4651 4655.output

* GB785058 (A)

Description: GB785058 (A) ? 1957-10-23

Improvements in or relating to the impregnation of sheet materials withsynthetic resin latices

Description of GB785058 (A)

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PATENT SPECIFICATION -785,058 Date of Application and filing Complete Specification: March 25, 1955. No 8872155. Application made in United States of America on July 22, 1954. : Complete Specification Published Oct 23, 1957. Index at Acceptance:-Classes 17 ( 2), B 9 A; and: 140, P 3 (E: F 4: G 5). International Classification:-A 43 b, 'D 06 b. COMPLETE SPECIFICATION A, Improvements in or relating to the Impregnation of Sheet Synthetic Resin Latices. Materials with ERRATU% SPECIFICATION NO 785,058 Page 5, line 69, for " 30 0 % by weight of an Inlonlc" read " 3 O % by weight of an anlonlc". THE PATENT OFFICE, 18th November, 1957 material with finely divided

particles of cellulose nitrate After drying this product was stored until ready for use, at which time the impregnated flannel was dipped into a solvert for 'the cellulose nitrate, applied to the appro-. priate shoe part and allowed to dry in a stiffened condition It is also known that sheet material such as flannel may be impregnated by dipping the flannel into an aqueous dispersion of synthetic resin, such as a synthetic rubber latex However in all the known processes-there are operating difficulties which arise because of the tendency of such a latex to deposit in the form of a dense impervious layer As a result of forming such a layer the porosity of the impregnated material is low and the ability of the material to absorb solvents is poor The low porosity and, poor solvent absorption prevents the achievement of thie greatest stiffnes's for a given composition of impregnated, fabric Therefore to obtain a' desired stiffness, according to known processes, heavier, 'flannels or other supporting materials, must be impregnated with a greater amount of xesin, and such pro,A cedures are commercially unattractive. In our'United Kingdoni Patent Specifica:;' tion No 766,866 there is disclosed and lPrice 3 s6 d l DB 00801/2 (e) /3603 150 11/57 R resin latex impregnation This process, in general, involves dipping a sheet material into an aqueous bath containing a vinyl, or vinylidene polymer or copolymer, a water ' soluble polyvalent metal salt, and a' non-ionic 65 dispersing agent which is water-soluble at room temperatures and up to about 40 C and insoluble at higher temperatures The, impregnated sheet is heated to a temperature of C to'120 C, causing the dispersing agent 70 to become insoluble and thus allowing coagulation to take place The impregnated sheet material prepared in this manner contains uniformly dispersed agglomerates of synthetic resin particles and the sheet material is 75 dry, flexiblie and easy to handle or to store. The present invention is an alternative procedure to that described and 'claimed in Specification No 766,866 The present ii vention provides' a two-step process for 80 impregnating a fibrous sheet material: 'with ( 1) an aqueous latex containing dispersed vinyl resin solids 'and,an anionic sirface-active wetting agent and ( 2) a coagulent for the dis persed resin solids in the form of an aqueous 85 solution of a polyvalent minetal salt to produiace a sheet material capable of being stiffened by treatment with a solvent for the resin In the h -7 "_x _ ±',,. -PATENT S Pi ECIFCATION:" ,; Lf a " ':'::: a ls' ", ' ""'-'" " -" Index at A:"epta-ce:: 1-Classes 17 ( 2), BA'; and:'140, P 3 (E: s'),:' ' ' ':'' ' ' -0-). Internatiomal"Classi catibn; 7 43 b,:'DOO,,":l: " M Nao 5887 ? 2/55 ' -, A t;;;g Y: Apphcation made in United States of America on July 22

>,954 k ^ W ffi t Comp fete Speciflcdtioh Published Oct 23, 1957 ' ' ' '; '-' Index -at Acceptance:-Classes 17 ( 2), B 9 A; and10 1 3 E 4 (-: International C 1 assificatfon 7-4 b: 'D 06 j,,40, P-( F 4, ' .: -;' -COMPLETE SPECIFICATION::' ''' Improvements in or relating to the Impregnation of Sheet Materials with Synthetic Resin Latices We,,THE CELASTIC CORPORATION, a Cor claimed a process whereby,certain relatively 45 poration organized and existing uinder the laws cheap synthetic resin latices may be imof the State,,of Dejaware, United States of pregnated in the form of finely divided parAmnerica,, located at Arlington, New Jersey, tides into, a flanne L sheet inaterial, which has-a United States of America, do hereby declare long storage life, and which may thereafter be ' the invention, forwhich we pray that a patent treated with a solvent for'the synthetic resin, 50 may be granted to us, and the method by applied to the shoe part, and allowed to dry which it is to be, performed, to be particularly and form a high -quality shoe stiffener -The described in and by the following statement:, sheet material utilized in the process of, the l O This inventionrelates to amethod-of stiffen said Specification No 766,866 may be of-the n:: ing a fibrous,,sheet material, and' more par lightest -grade and yet be impregnated, with 55 ticularly it relates to -a method of preparing sufficient resin to be stiffened to a very high shoe stiffeners,by treating a sheet material degree, because -the process produces a hilhy'with a synthetic resin latex porous' impregnated fabric having the ability High, quality, shoe stiffeners in the past have to absorb larger percentages of solvhrent than c been made by 'im pregnating a flannel sheet has ever been achieved by the use of synthetic 60 material with finely divided particles, of cellu resin latex impregnation This process, in lose nitrate After, drying this product was general, involves dipping a sheet material into stored untii ready for use, at which time the a aqueous bath ontaining a vinyl, or impregnated flannel was dipped into a solvent vinylidene polymer or copolymer, a water l. for'the cellulose nitrate, applied to the appro soluble polyvalent metal salt, and a' non-ionic 65 priate shoe part and allowed - to dry in a dispersing agent which is water-soluble at stiffened condition she room temperatures and up to about 40 C and It is also known that sheet material such as insoluble at higher temperatures The imflannel may be impregnated by dipping the pregnated sheet is heated to a temperature of flannel into an aqueous dispersion of synthetic 40 C to'120 C, causing the dispersing agent 70 resin, such as a synthetic rubber latex However to become insoluble and thus allowing in all the known processes-there are operating coagulation to take place The impregnated difficulties which arise because of the tendency sheet

material prepared in this manner conof such a latex to deposit in the form of a tains uniformly dispersed agglomerates of syndense impervious layer As a result of forming thetic resin particles and the sheet material is 75 such a layer the porosity of the impregnated dry, flexible and easy to handle or to-store. material is low and the ability of the material The present,invention is an alternative proto absorb solvents is poor The low porosity cedure to that described and claimed -in and poor solvent absorption prevents the Specification No 766,866 The present inachievement of the greatest stiffness for a given vention provides: a two-step process for 80 composition of impregnated fabric Therefore impregnating a, fibrous sheet material 'with to obtain a desired stiffness, according to ( 1) an aqueous Iatex containing dispersed known processes, heavier flannels or other vinyl, resin solids'and ani anionic surface-active supporting materials, must be impregnated wetting agent and ( 2) a coagulent for the diswith a greater amount of resin, and such pro persed resin solids in the form-of an aqueous 85 cedures are commercially unattractive solution of a polyvalent metal salt to produce a In our'United Kingdom Patent Specifica sheet material capable of being stiffened by tion No 766,866 there is disclosed and treatment-with a solvent for the resin In the lPrice 3 s6 d l UED M 2 Cij 2: : A 7855058 -present process the sheet material 'is im-' 'tibn and, at least partially, dried, and then pregnated&with a resin latex in one step and impregnated with the resin latex, stripped and -freated' with coagulant in a separate step The dried In still a third embodiment, a creamed order of treatment is immaterial, and there latex is prepared by adding to the above-' fore the sheet'-materialmay:bb -impregnated ' described resin latex enouglf coagiilant salt to 70 with latex either before or after the sheet cause the watery latex to coagulate partially material is contacted with the latex coagulant and to have a creamy consistency Thie fibrous: The latex particles are agglomerated irmme sheet material is first impregnated with this diately upon contact with the coagulant in the creamed latex, stripped, and then impregnated present process, while in the process of the with a dilute coagulant solution and dried 75 copending application agglomeration does not Each of the above methods produces a dry, occur until the impregnated material is heated flexible, sheet material impregnated with resin It is an object of this invention to provide a agglomerates, and this material, after drying, novel method for stiffening fibrous materials may be stored for long periods of time without It is another object of this invention to prepare suffering harm due to chemical or physical 80 high quality shoe stiffeners by using a synthetic change This material

is capable of being resin latex as the impregnating medium It is stiffened by treatment with a volatile solvent still anotherobject to provide a two-step pro-: for:the resin Upon evaporation lof the solvent, cess for impregnating fibrous sheet materials the-shleet material stiffens. which are capable of being stiffened by sub In the preferred embodiment of this inven 85 sequent solvent treatment tion an impregnating medium is prepared by The above objects are accomplished in mixing at room temperature, 3 parts by weight accordance with the process of -this invention of an -aqueous polystyrene latex contaifiing by impregnating a fibrous sheet material with 50 % solids, 1 part of an aqueous latex of a an aqueous latex of a synthetic vinyl resin The copolymer of -styrene and butadiene' (in the 90 sheet material may be treated prior to the approximate proportion of 80 parts styrene to above-latex impregnation 'step -with a poly 20 parts butadiene) containing 45 %' solids, and. valent metal salt coagulant, or the sheet 1 % by weight of resin solids of an anionic material may be treated with a solution of such surface-active organic phosphate or sulfonate a coagulant by a step-subsequent to' the latex as a wetting agent The desired sheet material 95 impregnation step The aqueous resin latex is then dipped into this latex and stripped of comprises from 20 % to 60 % by weight 'of excess liquid by passing between closely spaced vinyl resin particles and at least 0 10 % and rolls The sheet material is then dipped into a preferably not more than 3 0 % by weight of second bath containing aluminium isulfate, in an anionic surface-active wetting agent This the form of a'1 % aqueous solution -Agglomera 100 amount of wetting 'agent is equivalent to 0 5 % tion of the resin solids takes place within the to 5 0 % by weight of the resin solids present sheet material at this time The material is In a step separate from the above latex irm then dried in air at '100 C and there is pregnation the fibrous sheet material is con-' recovered a dry, flexible, impregnated sheet tacted with an aqueous solution of a polyvalent material containing 60 % to '70 % or more'105 metal salt, -normally in the form of a 5 %' resin solids in the form of small 'agglomerates aqueous solution Whether the coagulant is dispersed throughout the sheet material. applied prior to or subsequent to the latex im Because of these agglomerates the sheet pregnation, the resin solids agglomerate immoe material is -highly porous and is capable of diately upon contact between the coagulant and absorbing a large amount of resin solvent which 110 the resin particles The agglomeration takes in turn is the principal factor permitting the place in the interstices of the impregnated achievement of a high degree of stiffness in the material

forming resin agglomerates in situ impregnated sheet miaterial After the sheet material has been impregnated When this impregnated material is ready for with the latex and the-coagulant, -it is dried, use as a stiffener, it is blanked into the desired 115 for example, in an air oven at 100 C, to form shape, treated with a volatile solvent for the a flexible composition, and' may at any time resin, such as methyl ethyl ketone, toluene, or thereafter be treated with' a solvent for the mixtures of these materials' with diluents, resin causing the dry flexible 'material to applied to the base which is to be stiffened, become stiffened and the solvent is allowed to evaporate, thus'120 There are several embodiments of this in producing a stiffened sheet material. vention, all of which produice the same dry, The following examples are given to illusflexible impregnated sheet material ' In one trate various embodiments of this invention. method, the fibrous sheet material is first im Parts and percentages are by weight unless pregnated with the above-described resin latex, otherwise specified ' 125 stripped to remove excess liquid, and then EXAMPLE 1 An impregnating medium impregnated withy an aqueous coagulant' was prepared by blending 3 parts of an aqueous solution, followed bydrying In a second pro latex containing 50 % solids in the form of cedure, the fibrous sheet material is first -p'Olystyrene and 1 part of an aqueous latex conimpregnated with an aqueous coagulant solu taining 45 % solids in the form of an 80/20 130 slightly stiffer and harder compositions as the butadiene proportion is reduced and softer more elastic compositions as-the:butadiene,proportign is;,inereased:, -,The,:samervariety of ?compositions can be obtained by mixing well 70 known plasticizers with; for example; polystyrene,, a polymerised vinyl or vinylidene halide or polymerised acrylates The latex used as starting material in the preparation of the impregnating bath of this 75 invention is a, colloidal dispersion of one or more of the above resins in an 'aqueous medium. Preferably, the dispersion contains from 40 % to 60 % resin solids, while the remainder is substantially all: water These dispersions or 80 latices are available commercially on the open market in: concentrations of 40 % to 60 % solids, or they may be prepared by knowi methods, such as dispersion polymerization. The latei of resin and water constitutes the 85. largest portion' 6 f the impregnating mixture of this invention -'and,,-the -additives described below constitute less than 15 %, of the total weight of the impregnating mixture, although there are some embodinfents of ibis invention 90 wherein a large amount of filler is employed, After all additives are incorporated into the latex, it may then be diluted if desired, and in any case will contain 20 % to 60 %

resin solids in the final form as -an impregnating bath 95 Anionic surface-active -',wetting agents are required additives to the latex utilized in this invention The wetting agent is' required to cause the fabric-tobe easily wetted byythe latex and thus permit the interstices-of the" support'100 ing fibrous materials to fill quickly and completely with the impregniating latex(' The more commonly known of, such compounds are the alkali metal organic sulfates, sulfonates, phosphonates, and phosphates,, in which the organic 105. group is a long chain alkyl -or alkyl aryl group. Included among these compounds are isopropyl naphthalene sodium sulfonate, 'the -dioctyl ester of sodium, sulfosuccinic acid, sodium alkyl sulfates, sodium -alkyl phosphates, sodium alkyl 110 o phosphonates, the sodium salt of 2-ethylhexyl. polyphosphate, ammonium soaps, and other commonly'known -;anonicg detergents. The preferred amount of the surface-active wetting agent may vary from 0 5 % to 5 % by 115 weight of the resin solids present When the solids content of-the latex is 20 % to 60 % the amount of the surface-active wetting agent becomes 0 1 % to 3 0 % by weight of the total latex Larger amounts than 3-% are not harm 120 ful to the process and the limit of 3 % is selected for economic reasons entirely Less than 010 % of wetting agent reduces the speed with which -the, sheet material may be impregnated and thereby' the efficiency of the-125 process, if time is-a factor in the process Coagulants which,may" be employed in the process' of this invention are the water-soluble polyvalent metal salts such as chlorides, nitrates, sulfates and, acetates-of, for example; 130 copolymer of styrene/butadiene 'To this latexblend, there was added 0 5 %: by weight -of resin solids of an organic phosphate surfaceact Ove agent salt under,the namen Victor ' Stabilizer" sold, by the, 'Victor 'Chemical' Works (Chicago, Ill) A piece of cotton flannel weighing 0 36 pounds per square yard was dipped into, a 1 % aqueous solution of aluminium sulfate, stripped of excess liquid by passing the wet fabric between rolls spaced: 033 " aparti and thereafter the fabric was dried at 100 C in an air oven The dried fabric was then dipped into-the above' described latexblend and passed between stripping rolls spaced 033 ': apart The impregnated fabric' was placed horizontally in an air oven maintained at 100 C and dried in that position, The' amount of resin solids in the dried impregnated fabric amounted to 69,% of the total weight of the impregnated fabric A portion of' this-impregnated fabric was tested tot determine its. ability to absorb a solve nt,for the resin The solvent utilized was a mixture of' 90 % by weight of toluene and 10 % by weight of a commercial petroleum naphtha fraction boiling "in'the range 6 ff 100

"'t 167 C The-material was sufficiently absorbent that 71 7 % -of the dry weight of the fabric was solvent Upon evaporation of the solvent material the fabric -30 is a stiff, boardy, material which is very tough and flexes with difficulty. As the major ingredient of the impregnating latex there may be employed, for example;polystyrene, polymethylstyrene, polyvinyl halides, polyvinylidene halides, polyacfylates, polyacrylonitrile, and polyalkylacrylates Copolymers of styrene/butadiene, high in styrene content and low in butadiene content are also operable It is desirable in many instances to employ a plasticized resin, such as a mixture of polystyrene and a copolymer of high styrene content and low butadiene content, the copolymer acting as a plasticizer and thereby causing the polystyrene to be less brittle although retaining its stiffness Other knowi' plasticizers such as organic esters, may be in, corporated with the base resin to reduce brittleness in the same manier as the styrene/' butadiene copolymer is used above Polymers of styrene or of vinyl halides are particularly desirable because of their availability and low cost Many varieties of resins and combinations of polymers have been found to be -useful in this process One useful group of resins is a copolymer of styrene/butadiene containing 4 % to 20 % by weight of butadiene A press ferred formulation-is a mixture of 3 parts polystyrene with 1 part of an 80/20 copolymer of styrene/butadiene, which mixture has a total composition of 95 %' styrene and 5 %. butadiene The proportions of polystyrene and the-styrene/butadiene copolymer cain be varied within the general range of 4-20 % by weight 65, of butadiene' in the total mixture' to, produce 785 058 ' 3. aluminium, magnesium,;calcium, iron, tin, copper, cobalt, chromium, ?: cadmium;and strontium Of' these various salts: calcium chloride, ferric sulfate 1 magnesium sulfate, and aluminium sulfate are-desirable, althotlgh the latter two are preferred because of their lower costs, better solubility characteristics, and the fact that they do not impart undesirable-color to the finished product The alums, such as:the i O ' potassium, 'sodium, or' ammonium aluminium sulfates are as desirable as aluminium sulfate as the coagulant in this process The 'amount of coagulant required will vary slightly with the chemical nature of the i-5 coagulant salt, the type and amount of resin employed, and' other reaction conditions For the preferred coagulant, aluminium sulfate, used with a latei of styrene/butadiene resin approximately 0 5 %' by weight of the resin solids present in the latex is sufficient 'to accomplish the desired result When used with other resin formulations, 'the amount of aluminium sulfate may vary from 0 5 % to 3 0 % by weight of-the resin solids For other coagulants, some of which-are known to be less active and less efficient than aluminium 'sulfate, the amount employed may be as' high

as 10 % or 1-5 % by weight of the resin Solids:. In one embodimnent of this invention, the resin latex is creamed by partially coagulating the latex solids, and theresulting creamed latex is utilized as the impregnating medium. Creaming of the' resinous latex-is accomplished by the well'known and simple procedure of ' adding small quantities of a coagulant tio the latex while the latex is being agitated As mote and more coagulant is added the latex-becomes creamy in appearance and in consistency, due to the formation of small agglomerates from 402 the original latex containing colloidal particles. The addition -of more coagulant will cause the formation of large lumps of resin which separate easily from the aqueous medium and this should be avoided Visual observation may be employed to control the' amount of coagulant required to reach a creamy consistency in the latex In general the amount of coagulant required is 0 25 % by weight of the resin solids in the latex. As a final: step in the preparation of the impregnating latex, water may be added to form the desired concentration of resin solids, which for most embodiments of this -invention will be from 20 % to 60 % by weight of solids. For the preparation: of shoe stiffeners, a concentration of 40 % solids has been found to be preferable The material which is to be 'stiffened may, in general, be any fibrous sheet material such as fabric, textiles, felted materials, mats or paper. The sheet material may be made of natural or synthetic fibres ora mixture of the two; In the case of shoe stiffeners-the material commonly employed is a cotton flannel, although nonwoven fibrous sheet material or even paper may be used in some cases Filler-materials may be incorporated info the impregnating medium of this invention: to serve several useful purposes,:For example, the filler mniay be'used to reduce the'cost'of the materials 70used in-the impregnating bath The useiof T' filler in many instances causes the impregnated material to be -more porous and therefore to be able'to absorb more solvent and:achieve a greater stiffness In some cases, the use of a 75 filler enhances the adhesiveness of the impregnated material to an adjacent laminating layer In the manufacture of shoe parts using the impregnated shoe stiffener of this invention it has been found that the incorporation 80 of filler material permits the' shoe stiffener to be handled easily when it is wet'with solvent and ready-to be incorporated into the shoe part and, futhermore, 'after the shoe part has been assembled 'theeic is less likelihood that -resin 85 solids will migrate from the shoe stiffener and cause visible spotting on the leather surfaces of the shoes Filler materials which may be used include water-insoluble fillers such as siliceous materials,

infusorial earths, bentonite clays, 90 and "Dicalite " (Registered Trade Mark). The'amount of Sfiller mnaterial which may be used may' be as much'as 100 % by weight of the'resin solids present and a range of values of 20 % to 50 % is preferable for most em 95 bodiments of this inventiori ' Thickeners have utility in this inyention when it is desired to impregnate a fabric with greater and greater amounts of resin solids, and when fillers and other ingredients of the 100 latex have a tendency to settle out -Thickeners which have 'been -used successfully include methyl cellulose and methyl carboxy cellulose. In the process of preparing a stiffened material such as a shoe stiffener, cotton flannel 105 or other supporting sheet material is -dipped, sprayed or covered with the impregnating latex, which is prepared according to the above description. The excess liquid is removed from'the wet 110 impregnated material by a suitable means such as coacting stripping rolls, or a wiper knife. Such an operation is capable of -loading the supporting material to the desired amount of % -or more by weight of impregnating I 15 solids if the original impregnating latex contains 40 % solids The stripped impregnated material is then contacted with an aqueous solution of a coagulant salt such as-aluminium sulfate or alum and finally dried-at 100 ' C or 120 greater to evaporate-the remaining water from the impregnated material In the previous description it has already been shown that the fabric may be treated with the coagulant prior to the step of impregnating with the latex or 125 the fabric may be treated with coagulant subsequent to the latex impregnation and it is not intended that this invention be limited to any patiualar order of procedure so long as there are two steps-involved in this process; namely 130 78.5058. with each of the following two liquid baths in 45 any order of treatment: ( 1) an aqueous latex containing 20 % to 60 % by weight of dispersed vinyl resin solids and at least 0 10 % by weight of an anionic surface-active wetting agent and ( 2) an aqueous solution of a poly 50 valent metal salt; drying the thus impregnated sheet material and recovering a dry, flexible, impregnated sheet material capable of being stiffened by the action of a solvent for said resin 55 2 A process according to claim 1 in which said vinyl resin is a mixture of polymeric styrene and polymeric butadiene, the mixture containing 4 % to 20 % by weight of butadiene. 3 A process according to claim 1 or claim 2 60 in which said polyvalent metal salt is aluminium sulfate. 4 A process for preparing shoe stiffeners comprising dipping a cotton flannel fabric into an aqueous latex containing ( 1) 20 % to 60 % 65 by weight of resin solids comprising 75 % of polystyrene and 25 % of

an 80/20 copolymer of styrene and butadiene and ( 2) 0 10 % to, 30.0 % by weight of ani inionic surface-active organic compound from the group consisting of 70 alkali metal alkyl and alkali metal alkyl arylsulfates, sulfonates, -phosphates, and -phosphonates; dipping the latex impregnated flannel into an aqueous solution of aluminium sulfate, and thereafter drying the twice-dipped 75 flannel and recovering a dry, flexible shoe stiffener. The process for preparing sheet material capable of being stiffened substantially as herein described 80 6 The process for preparing shoe stiffeners substantially as herein described. ( 1) an impregnation of the, fabric with a resin latex and ( 2) an impregnation of the fabric with an aqueous solution of a coagulant salt. After the second impregnation step in any of the above process alternatives, the impregnated material contains small agglomerates of resin particles uniformly dispersed throughout the sheet material After drying to remove the remaining water, this material may be stored if desired, or it may be used in the production of a stiffened article of manufacture, such as a box toe or counter in a shoe, a laminate with other materials 'and shaped molds The stiffening process is accomplished by treating the dry, impregnated material with a solvent for the resin, forming the solventtreated material into the desired shape and allowing the solvent to evaporate leaving a stiff, self-supporting, article The solvent for the polystyrene resin may be methyl ethyl ketone, toluene, or mixtures of these materials, and the solvent for the polyvinyl chloride resin may be methyl ethyl ketone, cyclohexanone, or mixtures of these materials with each other or with diluents. The process of this invention is particularly useful in the preparation of shoe stiffening materials such as box toe or shoe counters and it also finds a wide variety of uses in the preparation of impregnated materials which areused to stiffen or otherwise strengthen material with which it is laminated The impregnated material of this invention may be used to repair sheet metal articles such as roof gutters, downspouts, fenders and bodies of automobiles. This material also finds use in covering the decks and hulls of small boats, in the preparation of artificial limbs, in the manufacture of puppets and display devices and in a variety of laminating applications.

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* GB785059 (A)

Description: GB785059 (A) ? 1957-10-23

Improvements relating to vinyl resin based sheet materials for use, forexample, as acovering material for floors and like surfaces



DE1059175 (B) FR1134353 (A) DE1059175 (B) FR1134353 (A) less Translate this text into Tooltip



PATENT SPEC IFICATINI N ' l, , , , l, '', PTNP I l A t N: - , " Of:' ' d _ E'"785059 e -Date of Application-andfi'irig>omple e Speif aeion: March 30, 1955. S t iNo9300155, l' '' - '. l B y Aplication nalein Italy on April 281 I ':. Comete Specification Published: Oct 23, 1957 ' ,: ' Index at Acceptance:-Class 140, A( 2 N 3 5 G 9 10 B 3 '. International Classification:-D 06 k ' ' -" ' , 'COMPLETE SPECIFICATION ' ' ' Improvements relatingto Vinyl Resin Based Sheet Materials for'Use, for example, as as'Covering Matierial for Floors and Like Surfaces ' ' We, SOCIETA DEL LIN Ot EUM SOCIETA PER -in the linear dimensions of the

material in'onie 45 AZ Io NI, a ' Limited Liability' -Company or -more directions '"The reason why pressure, organised under the laws of Italy, of 28 Via 'for example in these forms,, produces relaxation Macedonio Melloni, Milan, Italy, do hereby 'of the material is that, in contrast to vulcanised declare the invention, for which we pray' that rubber, which is inherently-elastic and capable a patent may be granted to us, and the method therefore of fully'returning to initial dimei S 50 bvwhich it is to be performed, to be particu sions when the stresses producing deformation larly described in' and by 'the 'following have been removed; a plastified vinyl' resin statement: -' mass, being a thermoplastic material, deforms ' This invention relates to vinyl resin based permanently, or' substantially 'so, under the sheet materials -for use,for example, as a applied stresses ' ' 55 covering material for fioors and like surfaces: The two opposing effects, of shrinkage and Such materials usually c ontain a substantial 'relaxation, generally occur 'in respectively proportion of a suitable plastifier, and it is different degrees-'in ha 'dimensional' ense, known that they tend to 'be disadvantageous depending inter alia on the position and by reason of their tendency to shrink' and also service conditions of the material Obviously, 60 to expand, the shrinkage and'-expansion, the in such a case only the net (resultant) effect latter being-usually referred to as "relaxation," of the two processes may be observed frequently occurring simultaneously and of It is':kno Wn, with a view to minimising the course in opposition to-one another in-'one and two effects of shrinkage and relaxation, to the same sheet of vinyl resin kbased material incorporate a afiller with the vinyl resin, the '65 Shrinkage is due to the effect-upon the effect of the filler in the'composition being to molecular structure of the vinyl resin of the reduce the percentage of vinyl resin therein presence in the composition of the plastifying -and proportionately the degree to which the agent Thus the plastifying agent, which processes of shrinkage and relaxation can usually requires to be present in substantial 'occur therein under any given conditions of '70 v:proportion,-causes a gelling or swelling of the service. vinyl resin component-of the composition with The presence of a filler in the vinyl resin resulting creep or spacing apart of the 'material produces however 'a marked molecules thereof and in course' of time this 'degradation of the material as regards certain creep or spacing apart 'of the molecules useful properties thereof, including resilience 75 may be reduced with resulting shrinkage of the -and resistance to wear and scratching, which material' either owing to loss: of' plastifying have to-be present-in high degree in a, material agent from the composition, e g through suitable for use as a floor

covering. evaporation, or through the effect of "thermo The present invention has had for its objet elasticity," by which is meant the elastic to provide an improvement' which will confer 80 recovery of a deformation,, such'recovery being upon a vinyl resin based sheet material such -confined by the limit of molecular creep, which structural characteristics as will prevent the is reduced as temperature rises ' appearance in the material of either shrinkage Relaxation: is -produced by the weight of or relaxation under any normal conditions of persons continually treading upon the material, service of the material and this,' without the '85 i.e In the case of a floor covering, and also 'necessary use of a filler for this purpose and by the weight of objects continually resting without impairing in any way or degree the -upon it and it generally results in an increase -peculiar features of vinyl-resins, in-particular lPrice 14 S 6 d: Price 4 A M. 2 ' f " 78 Q 59- 75: their marked resiliency and resistance to wear-ing and scratching. Akcc 6 ording to the invention, there is provided a laminated material for floor covering and like purposes comprising at least two laminae composed of a highly plasticised, highly resilient, wear and scratch resistant polyvinyl resin devoid or substantially devoid of filler material, and at least one other lamina composed of a vinyl resin which in lamina form is substantially non-deformable in' the plane of the lamina, this second mentioned lamina, or in a case where there are two or more, said second mentioned laminae, constituting a reinforcing element in the material effective to stabilize the first mentioned laminae and therewith the materia as a' whol againist j 6th hrinkage and relaxation, the -componeiint 'laiinae' of the imaterial being firmly bonded to one another therein and the resilient -laminae, or in a case where, there are more than two resilient laminae, two of the resilient laminae, forming respectively tle outer laminae of the material, one-of them carrying the w earing surface thereof For convenience in-the further description of -the invention and i the,appended claims the-laminae of plastified yinyl resin in the 39 laminated material will be referred to as the "resilient laminae "and -the other lamina or laminae will be referred to as the "nondeformable lamina, (or laminae)' " The arrangement -of the laminae in the laminated material may vary, for example to suit the particular service requirements of the material Owing,'to the absence or substantial absece of a filler ingredient in the resilient :40 laninae, a-material is-provided which is particularly suitable to withstand the -stresses which are produced in it under the conditions of use of the material, and inwhich moreover thl remarkable resilience

characteristic of C 45 vinyl resins is enhanced as compared with the use as heretofore of a filler ingredient in the resin material In a case where there are more than three lminae in the material, the -two types of 5.0 laminae (resilient and, non-deformable), as regards at least the majority of the laminae of the -material, may be arranged in alternate sequence as regards the order in which - they are superposed: upon one -another in the material -Alternatively, in a case where there are five, or an unevennumber more than five, laminae in the material, the two types -of laminae may be so arranged-that each nondeformable lamina is sandwiched between two -60 resilient laminae' There may:be-in the material two or more resilient ': liminae arranged in immediate success ion, i e unsepar ted from_ one another by an intervening nonii-deformable lamina, the arrangement generally being one in which, as in an embodiment of the invention hereinafter described, the lamina carrying thewearing surface of the material is one of suh two or nmore resilient lamina? rranged irishnid ate succession 70 The non-deforniabl: laminaiar laminae may conveniently be composed of'-fpire viiyl:esin, X by 'Which is meant vinyl resin dev soiinof-a content of either a plastifier 6 rsa- filler;'qr it may be composed of a vinyl Resin _which-con '75 tains a small proportion of aplast 'fier or a small proportion of a suitable filler. : Thi manufacture and general -structuire of. the laminated material of this invention will now be described in greater detail with refer 80 ence to an embodiment of the invention, it being understood that in the preparation of the'individual'lamiriae and-the'assdmbling and bonding' of the 'se iminam'tog'ether conventional technique in the art of manufacture of 85 vinyl resin floor covering materials is followed. The mixing of the vinyl resin with the other ingredients to form the respective laminaforming compositions:is carried out in any suitable mixer, e g a Banbury-mixer 90 By way of example, the two compositions -may have respectively the following percentage (by weight) compositions: Non-deformable lamina-forming composition: Polyvinyl chloride 90 95 Plastifying Agent 9 Stabilising Agent (Filler) 1 Resilient lamina-forming composition: Polyvinyl chloride 65 -Plastifying Agent Z5 100 Stabilising Agent (Filler) 3 Colouring matter including pigmnents -7Suitable plastifying agents include, fotinstance, the-dioctylphthalate and polyesters 105 of the " Paraplex" (Registered Trade Mark) type produced by Roehm & Hass of Philadelphia Suitable stabilising agents (filers) include, for instance, the basic lead silicate and 110 sulphates and the calcium and cadmium stearates. -After being processed under -heat qo a cylinder rolling mill of the

open-roll type,: the resulting composition, in a heated condition, 115 is caldndered in preparation for milling into larnminae having a thigkness of 0 5 to 0 6 mm and a length and width conforming with the dimensions required for the final {larninated) product 120 -In order to ensure a perfect bond between the non-deformable laminae and the resilient laminae, in spite of the marked difference between the two types of laminae as regards elongation characteristics, the surfaces of the 125 non-deformable laminae are:preferably treated -with a -solution of a vinyl polymer or co-polymer n a suitable solvent, e g cyclohexanone or chlorobenzene. The laminae to form the laminated product 130 material being firmly bonded to one another therein and the resilient laminae, or in a case where there are more than two' resilient laminae, two of the resilient laminae, forming 50 respectively the outer laminae of the material, one of them carrying the wearing surface thereof.

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* GB785060 (A)

Description: GB785060 (A) ? 1957-10-23

Process for obtaining bleached semi-chemical pulp



BE536814 (A) CH332820 (A) DE1034473 (B) FR1129498 (A) BE536814 (A) CH332820 (A) DE1034473 (B) FR1129498 (A) less Translate this text into Tooltip

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PATENT SPECIFICATION A 785 11 tl 7 vv v Date of Application:ond filing Complete Specification: April I, 1955. No 9496/,55 Application made in Germany on April 8, 1954. Complete Specification Published: Oct 23, 1957 y: ' ' Index at Acceptance:-Class 2 ( 2), W 2, W 3 A( 2 A 2 B 4 C 8: 10 12 B). International Classification:-D 21 c COMPLETE SPECIFICATION Process for Obtaining Bleached Semi-Chemical Pulp We, ZELLSTOFFFABRIK WALDHOF, a German Body Corporate, of 156, Sandhoferstiasse, Mannheim-Waldhof, Germany, 'do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:, The object of the invention is a process for obtaining bleached semi-chemical pulp from cellulose-containing raw material, such as wood, and annual plants. For some time, products which can be included under the term "semi-chemical pulp," have been known in the art They are identified by the feature that the cellulose-containing raw 'materials are first only partially disintegrated 'by chemical means and the pulping of the intermediate-product so obtained is completed by mechanical means The semichemical pulp obtained is regarded technicallyin respect of the process as somewhere in the middle between ordinary chemical pulp which is completely disintegrated by chemical means and mechanical wood pulp In the production of semi-chemical pulp the partial chemical disintegration is pursued only until the lignin of the centre lamella of the raw material becomes. soft and is only partly dissolved out without, however, a complete dissolving out of the lignin occurring -and without, in particular, large quantities of carbohydrates being removed By this means much higher yields are obtained than with the normal disintegration of chemical pulp As compared with mechanical wood pulp the advantages are obtained that, in the first place, less energy is required for pulping, during which process, moreover, less damage is done to the individual fibres and, owing to the fact that a portion of the lignin is dissolved out, a purer product is also obtained which, however, naturally contains much larger quantities of non-cellulosic substances than ordinary chemical pulp which is fully disintegrated chemically.

In contrast to mechanical wood pulp, it is possible in the case of semi-chemical pulp, to use the product for -high' grade purposes, for example, for the manufacture of quality papers. In such cases a special problem is caused by 50 the bleaching of the product; owing to the numerous substances accompanying the cellulose; for, on the one hand, a high degree of whiteness and purity is demanded"for many purposes of use, and on the other hand; the 55 essential advantage of the semi-chemical process over the completely chemical disintegra tion, namely, the much greater yield, should not be lost by removing an excess of accompanying materials ' It is therefore not imme 60 diately possible to transfer the processes which are known and usual for bleaching ordinary chemical pulp, to the bleaching of semi-chemical pulp Since with ordinary chemical pulp the object is always to remove as much of the 65 impurities contained therein as is required by the intended purpose of use of the product, and in practice the only possible reduction of the yield is' that: resulting from the removal of these impurities, the choice of the bleaching 70 process depends in general only on the cost involved In the bleaching of semi-chemical pulp, on the other hand, consideration -must be given not only to the risk of an undesirable reduction in yield but also to the chemical 75 nature and the physical structure of the intermediate product, which,-being only 'incompletely disintegrated chemically, can be largely influenced by the chemical bleaching process, By the partial chemical disintegration process, 80 in contrast to the complete chemical pulp disintegration process in which the individual fibres are chemically exposed, the fibre unions are here substantially maintained and are only loosened or pre-softened From all this it 85 appears that many points of view must 'be considered in the bleaching of semi-chemical pulp which make necessary a special choice of the bleaching process to be used and, in certain cases, a special arrangement thereof 90 ( _:-, -_:; 1: ; ' ' -785,060 Numerous processes for obtaining bleached ge'i-chemidal' pulp have already been proposed All these processes, however, have many important imperfections These originate partly in the disintegration process and partly in the bleaching Whilst no great care is needed for the complete chemical disintegration process and the process may be carried out vigorously, in the case of the semi-chemical disintegration of the semi-chemical pulp process, on the other hand, it is necessary to proceed very carefully and with accurate control of the conditions, so that, on the one hand, excessive disintegration with a reduction of the yield and strength of the product does not occur, while on the other hand, the presoftening of the fibre ufion-is sufficient During the subsequent mechanical finishing it must be ensured that the most complete distribution of

the material into the fibres occurs without thelatter being excessively damaged; at the same time, however, care must be taken to avoid unnecessary consumption of power These various conditions which should be observed make it difficult to obtain a really perfect product On the other hand, with the previously known methods, if a good yield was obtained, a semi-chemical pulp was always produced which still contained more or less undefibred bunches of fibres which give rise to trouble during the subsequent processing and can only be incompletely bleached and with difficulty and, therefore, have a disturbing effect on the cleanliness of the product. The processes proposed and normal hitherto for the bleaching of semi-chemical pulp showed considerable imperfections In the majority of cases the processes used previously -for the bleaching of normal chemical pulp were simply applied to the bleaching of semi-chemical pulp with very few or no variations at all However, from-the above it is already apparent that such simple transferences could scarcely lead to success In particular, the non-uniform nature of the product, that is to say, the bunches of fibre still contained therein, made really good bleaching difficult or even impossible In addition a uniform chemical decomposition of wood is not-possible in practice, as is known Whilst it is comparatively easily possible to remove the imperfectly disintegrated portions by sorting in the case of normal chemical pulp, this is not possible with semi-chemical pulp If, however, a sufficiently and uniformly bleached semi-chemical pulp was required, then it was hitherto necessary, owing to the resistance which the incompletely disintegrated wood portions offered to the bleaching,:to bleach much more intensively than normal, and this led to an undesirably high expenditure in bleaching agents and also damage to the fibre. It has now been found that it is possible to obtain bleached semi-chemical pulp from cellulose-containing raw material, such as wood, annual plants'and the like in a simple and effective manner if the raw material is first subjected to a partial chemical disintegration then bleached, and finally mechanicallydefibrated Surprisingly it became apparent that, by operating in this manner, it was also 70 possible to influence the bunches of fibre insufficiently affected by the chemical partial disintegration with a favourable chemical effect during the subsequent bleaching, so that with the mechanical finishing effected during the 75 last stage a practically complete defibration may take place At the same time, the, bleaching effect was also improved relative to the previously known processes This was not to be expected, since in the hitherto-known processes 80 for the production of semi-chemical pulp it was precisely the still-coherent bundles of fibre and incompletely-disintegrated wood

portions which had given rise to the greatest difficulties -in the bleaching treatment By the 85 invention it is therefore possible, both to improve the semi-chemical pulp disintegration and so to obtain a uniform and valuable product simultaneously with simple means and without additional operations, and also to 90 increase the bleaching effect so that a further improvement in the product is obtained. The partial chemical disintegration may be effected according to the invention by various known processes In a further development of 95 the invention it has proved to be particularly favourable to carry out the process with an acid sulphite solution For, apart from the advantages of the process which the sulphite disintegration has, for example, relative to the soda 100 or sulphate process, a product is obtained therewith which, in particular, makes possible the effect achieved by the invention in a particularly favourable manner. The bleaching following the chemical partial 105 disintegration may be carried out in various ways It is usually sufficient to use only one bleaching stage; however, multi-stage bleaching is obviously also possible All the known agents may be used as bleaching chemicals, 110 such as chlorine bleaching agents and per-compounds such as peroxides, per-acids and their salts The bleaching may be effected, according to the bleaching agents used, in acid, neutral or alkaline medium As an extension 115 of the invention it has proved to be of special advantage to carry out the final bleaching in alkaline medium When using a multi-stage bleaching it is therefore sufficient for the last stage to be effected in alkaline medium If 120bleaching is effected only in one stage, it is, of course, of special advantage to provide an alkaline bleaching in this stage It is preferable for the bleaching to be carried out with a high pulp consistency 125 It has proved to be expedient in many cases to carry out a mechanical preliminary defibration already between the chemical partial disintegration and the bleaching This mainly depends on the type of raw material used, on 130 'C 5 about 30 % of the added' quantity of wood being 'dissolved out The product obtained is washed in water and the excess water is removed The chippings now have a dry content of about 25-30 % They are 70 coarsely defibrated in a toothed disc mill adapted to coarse grinding in such manner that more than half the material is obtained in the form'of bunches of fibre Simultaneously with the'defibration or directly thereafter, the mass 75 is intimately-mixed' with such a quantity of a solutioni containing 5-7 % each 'of sodium peroxide and sodium silicate that 4 5 % sodium peroxide and 5 %/ sodium silicate are used on bonfie-dry fibrous substance After the mixing 80 the fibrous material is yielded with a pulp consistency of about 22-25 % (The term "pulp consistency ' defines the concentration of cellulose in water expressed as a percentage by weight) It is stored with this

pulp consistency 85 at room temperature' until the bleaching agent is substantially coinsumed; whereafter the fibre mass is separated without'previous thinning into individual fibres' by means -of a double pulveriser The fibre pulp yielded is further 90 worked up in the usual manner after intermediate washing About 13 5 'tons of'the above absolutely dry fibrous material are obtained. If the product obtained in this manner is compared with such a product in which the 95 division into individual'fibres is effected under otherwise equivalelit conditions directly after the chemical partial disintegration and is only then bleached, the-much-greater purity of the -material produced according to ihe process of 100 the invention is-striking The material is practically free of fragments and -bunches of fibre and makes possible the formation of a homogeneous and uniform sheet of excellent strength With the-same degree of beatinig a 105 continued tearing strength (i e the strength of a partly torn sheet on further tearing from the initial tear-cald'ulated according to 'BrechtImset) of 120 was obtained for the product according to the invention and Ai folding num 110 ber (i e the number of double folds possible without breaking) of 1785, as compared with a continued tearing strength of 68 and a folding number of 900 'in the case of the product obtained according to the known 'process 115 Example 2 tons of white barked birch wood are subjected in the form of chippings of about 20 x x 5 mm'to a chemical partial disintegration with the use of a bisulphite cooking liquor con 120 raining about-5 % sulphur-dioxide and about' 1 % Ca O, with a ratio of cooking liquor to wood of 4 5:1 and a disintegration temperature of C, whilst the disintegration is continued until about 20 %,6 f the quantity of added wood 125 is dissolved out ' The product obtained is washed with W 5 ater' and -the excess water is removed The chippings 'have, under these conditions, a 'dry content of about 30-35 %. They are coarsely defibrated in an intermediate 130 its degree of disintegration before boiling and on'the nature of the chemical partial disintegration Whilst a mechanical preliminary defibration is generally not necessary, -for example, when processing annual plants, such pro' limin'ary defibration may be applied in the processing of wood if a semi-chemical pulp is to be obtained with a particularly high yield, that is to say, with a particularly mild chemical pre-disintegration; nevertheless, the degree bof comminution should not be taken too far before the boiling ' ' The preliminary defibration, the bleaching and 'the final splitting-up into separate fibres' may be' effected with any desired pulp consistency: IR has proved to be particularly suitable to work' with the highest possible pulp consistency Subsequent to the bleaching it is in many cases unnecessary to effect washing out or thinning The process according to

the invention may be carried out under greatly varying conditions, according-to 'the raw material to be processed, the product desired and the other requirements resulting' from the existing situation ' The' optimum conditions should be ascertained from case to case according to given stipulations It was, however, found that the following method of operation is particularly'preferable and therefore fulfils most of the conditions in a favourable manner The raw material is first subjected to chemical partial disintegration which is taken only far enough for a ' part of the substances causing the mechanical cohesion of the -plant cells, such as the lignin, hemicellulose and pectine, to be dissolved out The intermediate product thus obtained is then first subjected to preliminary defibration under such conditions that a fibre pulp containing a preponderant amount of fibre bunches-is obtained This fibre pulp is then freed of a portion -of the fluid, if necessary after a washing, then mixed with 'any chemicals required, in the case of a peroxide bleaching, for example; with up to 10 %, preferably 2-4 %, dissolved silicate 'calculated on absolutely dry fibrous material, as well as with up to 2 5, preferably 0 125-2 5, gramme-equivalents per kilogram of absolutely dry fibrous material of a bleaching agent active in alkaline medium, such as hydrogen peroxide, sodium peroxide, hypochlorite, and salts of per-acids 5 preferably in the presence of 0 5% alkaline hydroxide calculated on-absolutely dry fibrous material, and afrer-sufficient. reaction with oxidizing agent, mechanically divided, in a pulping apparatus, for example, a disc mill, conical pulping mill or an edge mill. Example 1 tons of white barked birch-wood are'subjected in the form of chippings of about 20 xx 5 mm to a chemical partial disintegration' with 'the use of a bisulphite cooking liquor with about 5 %- sulphur dioxide and about-1 ':/YTO,' using a ratio of cooking liquor 'to 'wood of. ' 4 5 1 and a disintegration temperature of 785,060, 4 78506 disc mill -adjusted to coarse grinding so that the major part of the material is obtained in the form-of bunches of fibre Shortly before, during or directly after this pulping operation the material is' intimately mixed with such a quantity of a solution containing 5 = 7 % each of sodium peroxide and sodium silicate-that about 2 %, sodium peroxide:and: about 5 % sodium -silicate are used on bone dry fibre substance Subsequently, the fibre material is stored at room temperature for 10 hours and then split up into separate fibres by means of a double disc mill without previous thinning; or washing The fibre pulp obtained is washed in the usual manner and further worked-up, About 15 tons of a practically splinter-free product of a bright colour is obtained.

Example 3: tons of white-barked birch wood are subjected to a partial disintegration and coarse preliminary defibration as described in Example 1 The coarsely defibred material is next intimately mixed with 5 % sodium hypochlorite and 5 % Na OH, calculated on bone dry fibrous material, in a solution containing 3 % each of the two substances and stored for about 1 hour at room temperature Subsequently, intermediate washing is effected in known manner After'the washing the fibre pulp is brought to a pulp consistency of 30 %,by means of a revolving filter and subsequently mixed in a double shaft mixer with 2 % Na 20 and 3 % sodium silicate in a 7 % solution of each substance After storing for about 8-12 hours the fibrous material is split up immediately into separate fibres by means of a double-disc mill and subsequently washed in known manner A fibre pulp of a high degree of purity and good whiteness is obtained. Example 4 tons of white barked birch wood are subjected to a chemical partial disintegration, a preliminary defibration and bleaching as described in Example 1 Before splitting up into separate fibres a known washing is effected removing the incrustations dissolved out during the bleaching Subsequent to the washing'the fibrous material is dehydrated by means of a revolving filter or worm press and split up into ' separate fibres in a disc mill The fibre pulp thus obtained is somewhat behind the products obtained according to Examples 1-3 in respect of its purity, but is, after the splitting up into separate fibres, practically free of the dissolved reaction products formed during the bleaching, so that washing after splitting up into separate fibres may be dispensed with. Example 5 tons of white barked birch wood are subjected to chemical partial disintegration, a preliminary defibration, bleaching and washing as in Example 4 The fibre pulp thus obtained is then split up into separate fibres with a pulp consistency of 2-10 % in a disc mill or a conical staff engine The pulp obtained by this operation is not so pure as that obtained in Examples 1-3; it contains instead a considerably smaller proportion of splinters, fibre-bunches and the like than a-fibre pulp which has beensplit up under-otherwise'identical conditions directly 70 after the chemical partial disintegration, that is to say; before the oxidizing after-treatment. Example 6 - 10 tons-of chopped wheat straw are subjected with the use of a bisulphite cookingliquor con 75 taining about 3 % SO and about 0 8 % Na OH at a boiling temperature of 115 C and a ratio of cooking acid to straw of 75:1, to a chemical partial disintegration, by which about 35 % of the added, bone-dry above-mentioned quantity 80, of straw is dissolved The material thus obtained is, after intermediate

washing, dehydrated on a revolving filter, whereby a dry content of about 30 % is regulated Subsequently, the material is intimately mixed with such an 85 amount of a solution containing 5-7 % each of sodium peroxide and sodium silicate that about 4.5 % sodium peroxide and about 5 % sodium silicate are used on dry fibre-pulp The material obtained after about 10-20 hours storage is as 90 in Examples 1, 4 and 5 further treated and split up into separate fibres. Example 7 tons of white barked birch wood are subjected in the form of chippings of about 20 x 95 x 5 rmm to a chemical partial disintegration with the use of a cooking liquor containing about 5 % sodium sulphite (Na 2 SO,) and about 1 % sodium bicarbonate (Na HC Oo) at a ratio of cooking liquor to wood of 4 5:1 and a dis 100 integration temperature of 175 C, the period of boiling being such that about 25 % of the added quantity of wood is dissolved out The product obtained is washed with water and the excess water is removed The chippings now 105 have a dry content of about 25-30 % They are coarsely defibrated in a toothed disc mill adjusted to coarse grinding so that more than half the material is yielded in the form of fibre bunches Simultaneously with the defibration 110 or immediately thereafter, the mass is intimately mixed with such an amount of a solution containing about 5-7 % each-of sodium peroxide and sodium silicate that about 4 5 % sodium peroxide and about 5 % sodium silicate 115 are used on bone dry fibre substance After mixing, the fibre material is yielded with a pulp consistency of about 22-25 % It is stored with this pulp consistency at room temperature until the bleaching agent is substantially used up 120 Subsequently the fibre mass is split up into separate fibres by means of a double disc mill, without previous thinning The fibre pulp obtained is further worked-up in the usual manner after intermediate washing About 13 5 125 tons of absolutely dry fibre material are obtained. If the product obtained in this manner is compared with a product in which the splitting up into separate fibres is effected immediately 130 785,060 whereafter, if desired after washing, the fibre pul p is freed from a part of the liquid associated therewith, treated with any chemicals necessary for the bleaching, for example stabilisers and bleaching agents, and, after the bleaching 45 agent used has acted sufficiently, is mechanically defibrated. 7 A process as claimed in claim 6, in which the bleaching step is carried out with a bleaching agent effective in alkaline medium, such as 50 hydrogen peroxide, a hypochlorite or a salt of a per-acid. 8 A process as claimed in claim 7, in which the bleaching step comprises treating the fibre pulp with up to 2 5, preferably 0 125-2 5 55 gramme-equivalents per kg of absolutely dry fibre pulp, of a bleaching agent effective in alkaline medium, and preferably also 0

5-10 % alkaline hydroxide, calculated on absolutely dry fibre pulp 60 9 A process as claimed in claim 8, in which the bleaching step comprises treating the fibre pulp with a mixture comprising up to 10 %, preferably 24 %, dissolved silicate, calculated on absolutely dry fibre pulp, and up to 2 5, 65 preferably 0 125-2 5 gramme-equivalents per kg of absolutely dry fibre pulp, of a peroxide, and preferably also 0 5-10 % alkaline hydroxide, calculated on absolutely dry fibre pulp A process as claimed in any of claims 70 6-9, in which the mechanical defibration is effected by means of a disc mill, a conical pulping mill or an edge mill. 11 Processes for obtaining bleached semichemical pulp substantially as hereinbefore 75 described with reference to the Examples. W P THOMPSON & CO,, 12, Church Street, Liverpool 1. Chartered Patent Agents. after the chemical partial disintegration under conditions which are otherwise the same, the much greater purity of the pulp produced according to the process of the present invention is striking The pulp is practically free from splinters and bunches of fibre and makes possible the formation of a homogeneous and uniform sheet of excellent strength properties.


* GB785061 (A)

Description: GB785061 (A) ? 1957-10-23

Improvements in or relating to electro-luminescent elements

Description of GB785061 (A) Translate this text into Tooltip



PATENT SPECIFICATION 7859061 Date of Application and filing Complete Specification April 4, 1955. No 9764/55. Application made in Netherlands on April 6,1954. Complete Specification Published Oct 23, 1957. Index at Acceptance:-Class 39 ( 1), 54 (A: C: D: F: J: K: Q: R), S( 6: 8). International Classification: -C 09 k. COMPLETE SPECIFICATION Improvements in or relating to Electro-Luminescent Elements We, PHILIPS ELECTRICAL INDUSTRIES nescence The invention has for its principal LIMITED, of Spencer House, South Place, object to provide improved electro-luminescent 50 Finsbury, London, E C 2, a British Company,, elements comprising electro-luminescent do hereby declare the invention, for which we materials which exhibit a strong alternatingpray that a patent may be granted to us, and current luminescence and, moreover, in many the method by which it is to be performed, cases, direct-current luminescence. to be particularly described in and by the fol According to the invention an electro 55 lowing statement: luminescent element comprises a layer of This invention relates to electro-luminescent electro-luminescent material sandwiched elements between two electrodes, at least one of which It is known that certain materials emit radi electrodes is transparent to light emitted by ation when exposed to an electric field Until said material upon its excitation, is character 60 recently, such phenomena have been described ized in that the electro-luminescent material principally with respect to those cases where is manufactured by a method in which zinc the electric field was an alternating field, but sulphide or z Inc cadmium sulphide is heated recently it has been found that with certain in a sulphurizing atmosphere at 700 C to materials luminescence occurs if they are 1200 C admixed with compounds of one or 65 exposed to a constant electric field The two more of the alkali metals, which compounds phenomena will hereinafter be referred to as produce sulphides in a sulphurizing atmos"electro-luminescence " Where it is deskir phere, and with activator compounds of one able to distinguish between the two, the

last or more of the elements manganese, copper mentioned phenomenon will be referred to as and gold 70 "direct-current luminescence" and the first By employing the above method to manumentioned as "alternating-current lumines facture the electro-luminescent material cence" The electro-luminescence may be grains are produced consisting of zinc sulobserved, for example, if a layer of such a phide or zinc cadmium sulphide, activated by substance is covered on either side with an one or more of the elements manganese, 75 electrode and a voltage applied between the copper and gold, which grains have a thin surelectrodes at least one of the electrodes being face layer consisting of sulphides, (which may pervious to the radiation produced include poly-sulphides), of one or more of the A few satisfactory, known electro-lumines alkali metals Although the phenomenon of cent materials contain as a matrix zinc sul the electro-luminescence of the compounds 80 phide or zinc cadmium sulphide and an activ produced in this manner cannot completely be ator, for example manganese or copper In accounted for, it is practically certain that it the methods of producing these electro is related to the sulphide layer on the grain luminescent materials measures different from surfaces If the electro-luminescent material those taken in the case of the production of a obtained is washed with water, so that the sul 85, photo-luminescent material from the same phides are dissolved, it is found that the matrix and the same activators must be material has lost its electro-luminescent pro = employed In the literature a few data are perties. found on this subject, for example, concern From a large number of experiments it has ing the use of zinc oxide or lead oxide, applied been found that the copper, manganese or gold 90 to or in the grains of the luminescent material, is absorbed into the interior of the electrothe photo-luminescent material being ren luminescent grains and that the sulphides of dered, it is said, electro-luminescent the alkali metals are always found in a thin These known methods provide materials surface layer. which exhibit alternating-current lumines The above method may be carried out in 95 cence, but substantially no direct-current lumi various ways For example, first photolrprico t e, luminescent zinc-sulphide or zinc cadmium the side facing the electro-luminescent layer. sulphide may-be produced by -heating, in-nor- To this -end use; may for example be made mal manner,' zinc sulphide in a sulphurizing of two glass plates, a surface of each of which atmosphere at 7000 C to 1200 C with activ is rendered conductive, for example by treatator compounds of one or more of the elements -ing it with tin oxide These surfaces thus 70 manganese, copper and gold and by-heating treated

with tin oxide are transparent to the the photo-luminescent'product thus obtained:'emitted radiatioh If desired, one of the again in a sulphurizing atmosphere at 700 C plates may of course be covered simply by to 1200 C in the presence of compounds of adhering to it a metal foil for example of aluone or more of the alkali metals, -which-latter minium In order to -isolate the material 75 compounds produce sulphides-in this silpliur completely from the surroundings, the gap izing atmosphere However, as an alternat between the edges of the joined-plates are ive the two measures according to this method filled for example by paraffin wax or lacquer. may be combined and as a further alternative In order that the invention may be readily first z Inc sulphide-or zinc cadmium sulphide -carried into effect, examples of methods of 80 may be-heated-under the said conditions with manufacturing the electro-luminescent matericompounds of one or more of the alkali metals, als will now be described:-: after which the product obtained is activated by heating it wjth compounds of one or more EXAMPLE I of the elements manganese, copper and gold A mixture of The sulphurizing -atmosphere may, for 1 ginm mol of Zn S, 85 example, consist of hydrogen sulphide, carbon 0 05 gin tiol of Li CO, disulphide, or nitrogen charged with sulphur 0 01 gmn mol of Mn(NOQ), Suitable compounds of the alkali metals are is produced and heated to 900 C in an IIH 25or example carbonates, nitrates, oxides or: atmosphere for about one hour The sub_hydroxides For the compounds of man stance obtained exhibits yellow electro-lumin 90 ganese, copper and gold use may be made of escence. those compounds which are normally used fox In the aforesaid example the lithium carproducing photo-luminescent sulphides, for bonate may be replaced by the carbonate of example carbonates, nitrates or oxides sodium, potassium, rubidium or caesium If .The luminescent compounds or materials desired, carbonates of more than one of these 95 exhibit an emission which is determined sub elements may be employed, the sum being -' stantially only by the interior of the grains then 0 05 gin molecule Instead of usingand not by_ the surface layer of the alkali the H 2 S-atmosphere, use may be made of an metalf sulphide atm Eosphere of C 52 vapour As a further The, copper and, gold content is preferably alternative, the H 2 S may be charged with subl 100 chosen between 3 10 and 5 10 a gram atom phur by passing HS gas over molten sulphur. per gram molecule of zinc sulphide or zinc If desired, nitrogen may be passed over molten cadmium sulphide If manganese is used as sulphur and the heating may be performed in an activators the manganese content is prefer-, this nitrogen charged with sulphur. ably chosen to be 10-3 to 8 10-2 gram atom of manganese, per gram-molecule of zinc sul EXAMPLE II 105 phide or zinc cadmium

sulphide '1 gm mol of Zn S, The content of alkali metal is preferably O 01 gmn mol of Li CO,, chosen to be I O to 5 10 gram atom of alkali O 06 gin mol of Mn COM, metal per gram molecule of zinc sulphide or are mixed This mixture is heated at a tem:zinc cadmium sulphide perature of 1150 C in an H 2 S-atmosphere 110 A As with the, known photo-luminescent -for about one hour The material obtained : materials of -zinc sulphide or zinc cadmium may be ground, if necessary, before use It sulphide and the activators manganese, copper exhibits yellow electro-luminescence. or gold, so-called charge compensation may EXAMPLE m I be applied by incorporating aluminium in the ' A mixture is made of 115 -_crystal lattice =-: Thus the activator content I gin mol of Zn S, may be chosen to be higher The aluminium 5 10- gin mol of AI(NO,),, content -is then: preferably chosen between 10-4 gm mol of Cu(NO,),, I 0-2 and I 0-4 gram atom of aluminium per 10-4 gin mol of Li 2 CO,. gram molecule of zinc sulphide or zinc cad The mixture is heated in a hydrogen sulphide 120 ^ mium sulphide atmosphere or carbon disulphide at 1100 C. The electro-luminescent elements in accord for one hour The substance obtained is ance with the invention may be constructed as ground and, if necessary, sieved before use. follows A thin layer of the material is cormn It exhibits green electro-luminescence. pressed, its thickness varying with the voltage' EXAMPLE IV 125 for-which the element is intended; this layer A mixture is made of -is sandwiched between two plates, the sur 1 gin mol, of Zn S, and faces of which are electrically conductive on 10-2 gmn mol of Li 2 CO, 785,061 785,061 and heated at 800 C in a hydrogen sulphide atmosphere for one hour The material obtained is ground and then heated again in a hydrogen sulphide atmosphere for half an hour with 0 03 gin mol of Mn(NO,)2 at 1100 C The product obtained exhibits yellow electro-luminescence. Instead of using lithium carbonate, use may be made of one or more of the carbonates of the other alkali metals As in the foregoing examples, the heating may take place in a carbon disulphide atmosphere or in nitrogen or hydrogen sulphide charged with sulphur. EXAMPLE V 1 gin mol of Zn Cd S is moistened with a solution of Mn(NO,)2 in a manner such that the mixture contains O 005 gin mol of the last-mentioned nitrate; after drying the mixture obtained is heated in a hydrogen sulphide atmosphere at about 1000 C for about one hour The product obtained is then mixed with 0 02 gin mol of Li CO,, heating being then performed in the sulphurizing atmosphere at 900 C This heating is continued for about one hour A yellow luminescing product

is obtained. EXAMPLE VI A mixture is made of 1 gin mol of Zn S, 7 10-4 gin mol of Al(NO,), 3.10-4 gin mol of Au(N Os)3 and heated in a hydrogen sulphide atmosphere at 11500 C for one hour The product obtained is ground and mixed with 0 04 gin mol of Li 2 CO, This mixture is heated in a carbon disulphide atmosphere at 1080 C for 45 minutes A product is obtained which exhibits green electro-luminescence.


* GB785062 (A)

Description: GB785062 (A) ? 1957-10-23

Improvements in or relating to a method and apparatus for preheating feedwater in steam power plant


PATENT SPECIFICATION : 785,062 Date of Application and filing Complete Specification: April 6, 1955. No 10102155, Application made in Germany on April 6, 1954. Complete Specification Published: Oct 23, 1957. Index at Acceptance:-Class 64 ( 1), A 6 International Classification:-F 22 d COMPLETE SPECIFICATION Impiovements in or relating to a Method and Apparatus for Preheating Feed Water in Steam Power Plant. We, SIEMENS-SCHUCKERTWERKE AKTIENGESELLSCHAFT, a German Company, of Berlin and Wemer-von-Siemens:strasse -50, 13 a Erlangen, Germany, do hereby declare the invention, for which we pray that a patent ' may be granted to us, and the method by which it is to be performed, to be

particularly described in and by the following statement: ' This invention relates to a method and apparatus for pre-heating feed water in a high pressure steam power plant operating on a regenerative cycle. a Every modern -steam power plant requires highly efficient pre-heating in combination with a low exhaust gas temperature of the boiler, and in the ranges of moderate pressures and temperatures this requirement can be met without difficulty The operating conditions of the plant at very high pressures and the attendant very high temperatures, for example of 300 atmospheres and 550 C respectively, initially constitute an obstacle to achieving this object in both respects at the same time. Installations for such high operating values must operate with various stages of superheating, and calculations for such a boiler show that by far the greater part of the heating surface (probably up to 80 %) carries superheated steam, so that a low exhaust gas temperature is not readily possible, because the high superheating temperature necessitates a correspondingly high flue gas temperature, or in other words the flue gas temperature cannot be lowered to a sufficient extent Little change is produced in this respect by providing additional' heaters for heating the combustion air, since a correspondingly high air temperature must also be produced in such heaters On the other hand, if the feed water pre-heating were correspondingly increased by flue gases for the purpose of lowering' the gas temperature, the disadvantage would arise that the efficiency of the regenerative cycle would lPrice 3 s 6 d l be substantially impaired particularly 'in the 45 lower stages Therefore, a new arrangement of the heating surface' must be sought vwith which it is possible to' lower the flue gas temperature without any detriment to the regenerative cycle, or in any case without any 50 substantial detriment thereto. There is known a steam power plant of the kind comprising a main' steam prime mover or turbine and a condenser associated therewith, in which plant the condensate from the con 55 denser is progressively reheated by passing the condensate through a series of heaters, and is returned as feed water to the boilers In this known plants the condensate from the main condenser is first heated by steam from an 60 auxiliary turbine, and is passed into an open feed water tank, from which the condensate is passed by a circulatiing pump directly to an economiser where the condensate is heated by the products of combustion escaping from the 65 boilers, the condensate being subsequently heated to boiling temperature by further steam from the auxiliary turbine This known plant is adapted to operate at low to moderate pressures with a boiler temperature of 70 approximately 340

F. In contradistinction, one aspect of the invention provides a method of pre-heating the feed water in a high pressure steam power plant generating steam at temperatures in the 75 region of 550 C and pressures in the region of 300 atmospheres, and operating on a regenerative cycle, wherein the feed water is caused to flow from the feed water tank through a regenerative heating stage (as hereinafter de 80 fined) operating at high pressure, and wherein all,, or part of the feed water is thereafter heated by the flue gases in a flue gas preheater (as hereinafter defined), the feed water, or said part thereof, being thereafter immediately -fed 85 to a following regenerative stage operating at high pressure for further heating. According to another aspect of the invention there is provided in, or for use with a .-:igh pressure steam power plant adapted to -genieraf& steam at temperatures in the region of 550 C and pressures in the region of 300 atmospheres, anhd adapted io 'operate on a regenerative cycle, apparatus for carrying into effect the method just indicated above, wherein means is provided for'passing the feed water from the feed water tank to the first of two or more regenerative heating stages (as hereinafter defined) operating at high pressure, and wherein means is located immediately between two of such high pressure regenerative heating stages for causing all, or part of the feed water to flow from one of such stages through a flue gas pre-heater (as hereinafter defined) located in the boiler flue to a next succeeding stag For a better understanding of -the invention and to show how the same may be carried into effect, reference will niow be made to the accompanying drawing W Vhich diagrammatically illustrates a boiler with its associated auxiliary plant: Referring now to the drawing there is shown a forced flow boiler 1, and the auxiliary plant associated therewith, the boiler being adapted to geherate steam at a temperature in the region of 550 C ahd at a pressure in the region of 300 atmospheres The auxiliary plant comprises a feed pump 2,-regenerative heating stages 3, 4 and 5 which operate at high pressure, and air pre-heaters 6, 7 and 8. By the term "regenerative heating stage" as used in this Specification, there is meant a stage where the feed water is' heated with a portion of steam, which has been bled off from the steam tuirbine of the plant, in a manner known per se with steam power plants operating on a-regenerative cycle A shut-off valve 9 is located immediately between the high pressure regenerative heating stages 3 ' and 4 A flue gas pre-heater 10, connected to both sides of the shut-off valve 9, is located between the air pre-heaters 7 and 8 The water, heated in the regenerative heating stage 3, is fed, beyond this stage, to the flue gas pre-heater 10 By the term "flue gas preheater"

as used in this Specification, is meant a pre-heater for the feed water, which preheater obtains its heat source from the flue gas, the -feed water being heated by heat exchange with the flue gas At the pre-heater 10, the water is further heated to a predetermined extent, for example, by 20 C, and is then returned to a point located at, or near, the inlet to the stage 4. In a modification, only a part of the feed water leaving the stage 3 is fed to the flue gas pre-heater 10, this part by-passing the stage 4 through a conduit 11 shown by a broken line, and being re-combined with the main stream of feed water, at a point located beyond the outlet of the stage 4 and before the inlet to the stage 5, after having been t 1 appropriately further heated The conduit 11, shown in a broken line, replaces that shown in an unbroken line, the stage 5, thein becoming in effect the stage succeedingsstage -'t-fbr sutch partial stream: : ' 70 The arrangement is thus adapled to extract heat from the flue gas current by, means of an additional pre-heater 'in order-&t': lower the waste gas temperature without - thereby appreciably influencing the efficiency of;the 75 regenerative cycle Naturality,-some reaction on the regenerative cycle will'be unavoidable, because, while the feed-water is at a higher temperature before a egenerative heating stage than when no additional heating surface 80 is etmployed, the temperature difference in the regenerative heating stage is reduced However, calculation si 6 ws 'that the gain in efficiency of the'-plant due to the provision of the additional heater is greater than the reduc 85 tion in the efficiency of the regenerative cycle. The reaction on the regenerative cycle becomes smaller in proportion as the extent to which the temperature in the regenerative heating stage can be increased 90


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