Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
  • D21H23/76—Processes or apparatus for adding material to the pulp or to the paper characterised by choice of auxiliary compounds which are added separately from at least one other compound, e.g. to improve the incorporation of the latter or to obtain an enhanced combined effect
  • D21H23/765—Addition of all compounds to the pulp
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L97/00—Compositions of lignin-containing materials
  • C08L97/02—Lignocellulosic material, e.g. wood, straw or bagasse
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/47—Condensation polymers of aldehydes or ketones
  • D21H17/49—Condensation polymers of aldehydes or ketones with compounds containing hydrogen bound to nitrogen
  • D21H17/50—Acyclic compounds
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
  • C08L25/04—Homopolymers or copolymers of styrene
  • C08L25/06—Polystyrene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L61/00—Compositions of condensation polymers of aldehydes or ketones; Compositions of derivatives of such polymers
  • C08L61/20—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
  • C08L61/22—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with acyclic or carbocyclic compounds
  • C08L61/24—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with acyclic or carbocyclic compounds with urea or thiourea

Definitions

• This inventionl relates :to the application ⁇ of f-'eo'ating" or limpregnating materials to fibrous cellulosic material, tocoatedor impregnated celluflosic bers obtainedl thereby, "and ⁇ to 'the ⁇ manu'- facture'of other articles fromthe coated-ordmapregnated lbers.
• pretreated eellulosio V1inmaterial into brous felted 1 ⁇ sneets or lvarticles f such as paper, .paper board, llifldedor prein'olded leellu'l'os'fic l articles andthe ilike.l
• the invention includes l'pro'cesses ffor fthe 'v'maniifacture of ⁇ new types' of lpaper, ,paper-fv board,
• the present invention fhas.asia :principal fobv:jee't anf-improvedf-metliod for the incorporation -o'f ⁇ impregnating agents 'fibrous "cellules-ie 'mateial'in suoh 4a mannerlthatmanyoffthef-dim- 1ciilties enumerated Vabove fare avoided; 11n "iaccordanfce with preferre'd embodiments ⁇ flo'f'the f in- ⁇ vl'enti'on,this is accomplished bylolitainngia'fniore uniform and completo coating or impregnation o"f 1the 'cellulosic 'libera-With the ir'np-'egnatin'g agent prior to the felting orfforihingfstep.
• a finftiie'r object is to eliniiiia'tej'rnany' of the ldileultie's ordinarily" eneoui'itered in the' ceag'ulationjoff inous -dispersions by lin'organi'c y precipitating agents suon as .aluminoluirig'dilnolties arising throughnon-uniform coverage of thelpiilpiiibers, formationoilstilry aggregates ofthepreopit ted material, and extremely slow drain'alg'l of Water :from agglomerated resin-fiber masses on the sheet-formingwir'e orscreen., ⁇ v
• resin-impregnated paper or paper board having superior properties can be prepared, as well as new types of products made from the treated paper of pulp by such conventional operations as laminating, molding, pressing, calendering, extruding and the like. Instead of forming the treated pulps or fibers, they can be shredded, chopped or ground to produce new types of insulating agents, molding powders, fillers for standard molding or casting resins, and the like.
• the present invention is based on the discovery of an unusual type of flocculation and deposition that is brought about by the action of cationic urea-formaldehyde resins in an aqueous system containing fibrous cellulosic material of the type of paper pulp suspended therein together with an aqueous dispersion of waterinsoluble coating or impregnating agents.V It has been found that in such a system the cationic urea-formaldehyde resin causes a controlled flocculation such that particles of the impregnating agent are uniformly coated upon or impregnated into the cellulose fibers.
• the cellulosic fibers When dispersed or deflocculated water-insoluble impregnating or coating agents are applied in this manner, the cellulosic fibers retain their property of felting or forming into shaped or sheeted articles despite the presence of large Aquantities of the impregnating agent, which in some cases may even be greater than the weight of the cellulosic fibers themselves.y Moreover, when the proper quantities of cationic urea-formaldehyde resin are applied in the manner hereinafter described a high degree of retention of the flocculated material by the cellulosic fibers is obtained, and losses of organic material in the white Water system are largerly avoided.
• the ⁇ process of the invention therefore comprises as an essential featurey the occulation of an aqueous dispersion of an impregnating agent in the presence of fibrous cellulosic material suspended inthe aqueous medium by the action of a cationic urea-formaldehyde resin.
• the distinctive type of ilocculation that is obtained when an aqueous solution of this type of resin is added to an aqueous dispersion such, for example, as an emulsion-polymerized polystyrene dispersion will be described and illustrated hereinafter in greater detail.
• the invention in its broader aspects includes any process wherein this flocculating action is used for the dispersion or incorporation of an impregnating agent into fibrous cellulosic material.
• one of the most importantfeatures of the invention is the discovery that the distinctive fiocculating action of the cationic urea-formaldehyde resin continues, and is in many instances actually enhanced, after the cationic resin has been absorbed on the brous cellulosic material.
• the importance, of this discovery resides inthe fact that the cationic resin, being distributed over and through the cellulosic fibers, causes a uniform dispersion and retention of the impregnating agent on the fibers after it has been flocculated.
• vresin-treated fibers in aqueous suspension exert an appreciable flocculating action on emulsions or dispersions of water-insoluble organic materials, and this is particularly evident when the emulsified or dispersed impregnating material carries a negative charge as when an anionic dispersing agent is employed in its preparation.
• the dispersed particles are occulated on the positively charged iibers forming a coating upon and around the fibers and permitting the formation of a mat of the coated fibers on a screen or paper machine wire, with substantial retention of both the fibers and the coagulated particles of the non-fibrous dispersion.
• the preferred cationic organic nitrogen compounds which are capable of condensing with diirnethylolurea or other urea-formaldehyde reaction products are water-soluble rpolyfunctional organic nitrogen bases; i. e., compounds having the ability to copolymerize with lurea-formaldehyde under acid conditions.
• Typical examples of such polyfunctional organic bases are the alkylene polyamines of the formula:
• dernethylolurea product is'preferablyformed under neutral orslightly alkaline ⁇ conditions, the latter being obtained-by theaddition of a smal-l vquantity -of basic materialfsuch' as sodium; hydroxide oratriethanolamine.
• a suitable quantity ofthe poly-- functional orga1iic-b ⁇ aseI is-then added-'as such or ⁇ after it has first beenreacted'- with formaldehyde'andthe resinsolution'is-'a-cidied-by the addition-o1 Vhydrochloric acid; nitric acidy or other strongly acidic material to'reducethe-pH ⁇ tothe polymerizing range,fwhich is about 1-4 and preferafbly Y1-2.-
• the resin-syrupis then further reacted o-r polymerized; preferably rat elevated Vtemperatureson the order-of 70-90' C., inI order'to bring about Ya polymerization or copolymerization' of the urea-formaldehyde yand* organic ybase andthereby-produce va cationic resin'.
• the relative proportions of polyalkylene poly- ⁇ arnine and primary ⁇ urea-formaldehyde condensation product may be varied over a wid-e range. This is an important advantage .of the invention, since it permits an adjustment ofthe degree of cationic properties .of the resin for lemulsions of Widely divergent characteristics including, vfor example, those containing anionic or non-ionic emulsifying agents.l Thus for somepllrposes -it' maybe most desirable to employ a resin preparedv from %V fbyeweight of.
• Cationic resins prepared from as much as 80 %j by Weight of a polyalkylene polyamine such'as tetramethylenepentamine and lby Weight of .the primary u re'aformaldehyde condensation product may be used in cases Where rapid curingof theresin is not important.
• Thepolyrnerized resinsyrup is preferably neutralized to a p I-I on the order of about .6 7 in order to obtain ⁇ a product whichV is stable on storage.
• the process of the invention may thus be used to .app-ly any'water-insclwble coating or impregnatingt agent in amounts varying from a few. lpercentgup to more thanthe weight of the fibrousv -cellulosic material'.
• agen We mean, of course. a material. which will coat or impregnato the cellulosic lbersand irnprove their; value. for their intended Zuse.
• the ⁇ following .types of materials of this. class are illustrative. of thewide variety .of impregQ hating agents Which'rnay be applied;
• Neoprene polymers Natural latices Synthetic latices Butadiene polymers Copolyiners of buta- Isoprene polymers diene, isoprene, etc.
• Thermopla'stic phenol-formaldehyde resins including phenol-aceta'ldehyde .and phenol-furfural resins and corresponding resins obtained from cresols and other alkyl phenols
• Oil-modified phenol-formaldehyde resins E'sters of rosinvvith polyhydric alcohols suchas glycerine, pentaerythritol, dipentaerythritol, polyallyl alcohols, etc.
• Polyindene resins C'oumaronc resins Vinylacetylene resins Vinso1" resin; i. e. residue from purified wood rosin Halogenated vinylacetylene resins Acetyl. gums Any of the above materials, either singly. or in admixture, may be applied to fibrous celllosic materials with the aid of cationic urea-formaldehyde resins by the process of the present invention.
• the impregnating agent is added to the aqueous stock suspension containing the cellulosic lbers as a dispersion in Water or aqueous liquid.
• the dispersions may require no added emulsifying or dispersing agents whatsoever, as in the case of natural latices.
• dispersions of finer particle size and :better impregnating properties are obtained with the ald of dispersing agents, and many types of dispersing agents may be used.
• any anionic or non-ionic dispersing agent may be employed in emulsifying or suspending the impregnating agents in Water or other aqueous liquids, and in certain cases the cationi-c emulsifying agents may also :be used.
• Typical anionic, emulsifying agents which have been employed with success are the soaps of aliphatic and cycloaliphatic acids such as potassium oleate, potassium naphthenate and the like, amine salts such as triethanolamine oleate; sulfated aliphatic compounds such as sodium lauryl sulfate and the sulfates of higher secondary alcohols and sulfonated castor oil; sulfonated products such as sodium keryl benzene sulfonate, sodium isopropyl naphthalene sulfonate, esters of sulfo-carboxylic acids such as esters of sodium sulfo-acetate, dialkyl sulfosuccinates, disodium monoalkyl sulfosucclnates; amides of sulfo-carboxylic acids such as lsodium sulfosuccnamates and the like, sulfon
• Ammonium or other water-soluble or waterdlspersible salts of alkyd resins of high acid number may also be employed, such as the products obtained by adding sodium hydroxide to condensation products of maleic acid and -glycerine, modified phthalic anhydride-glycerinefatty acid condensation products of high acid number, polyhydric alcohol esters of terpenemaleic acid condensation products and the like.
• any suitable :wetting or emulsifying agent may be used in practicing the invention.
• Any fibrous cellulosic material capable of ad-y sorbing cationic urea-formaldehyde resin from an aqueous solution thereof may be coated or impregnated by the process of the invention.
• a wide variety of fibrous cellulosic material used in the preparation of paper, board, molded resin fillers and the like may be used, such as kraft pulp. rag pulp, soda, sulfate, ground-Wood, ⁇ sulflte pulp and alpha pulp.
• other forms of fibrous cellulose such as cotton lnters, and the like may ibe Iemployed.
• These materials may be used alone or in adrnixture with fibers from other sources, s-uch as jute, hemp, sisal, strings, chopped canvas, asbestos fibers, glass fibers, and other material, either cellulosic or non-cellulosic, that may improve the impact resistance, mechanical strength or other properties of the formed or molded impregnated material.
• Typical products that may be improved by the process of the invention are -waterproof or moisturevaporproof paper, paper or board containers or cartons for milk, butter, foods, etc., resin-impregnated laminating paper, abrasives composed of resin-impregnated paper coated with abrasive particles, molded articles, premolded articles, electrical insulators, filter paper, heat-insulating paper, or loose masses of unfelted and unmolded impregnated cellulose stock used for air filters, dust filters, heat insulation and the like.
• the particular procedure whereby the impregnating agent is occulated and coated on the brous cellulosic material may vary somewhat with different impregnating agents, but usually follows the same general plan.
• the cellulosic material is preferably rst suspended in water and may be beaten for shorter or longer periods of time, after which the stock may be brushed out in a Jordan engine or other refining machine if desired. Any desired ratio of cellulosic material to water may be maintained but We prefer to operate at a stock consistency of about 0.5% to 6%.
• the cationic urea-formaldehyde resin is then added, preferably in the form of an aqueous solution of about 5%-l5% resin solids, after which the stock suspension is preferably allowed to stand for anywhere from 15 minutes up to 3-4 hours or longer.
• This period of aging is not a lnecessary step, since the adsorption of cationic resin by the paper pulp is quite rapid, but the subsequent behavior of the impregnated stock on a paper-making machine is much better when the addition of the impregnating agent is delayed for this period of time.
• the pH of the stock during the adsorption of the cationic urea-formaldehyde resin and prior to addition of the impregnating agent should preferably be within the range of from about 1 to about 6 since the resin retention is not as good at higher or lower values.
• the impregnating agent is introduced in the form of an aqueous suspension, preferably of relatively ne particle size.
• the flocculating action of the cationic urea-formaldehyde-polyamine resin is not dependent on the particle size of the added impregnating agent, but a much more uniform coating of the cellulose fibers and better performance on the paper-making machine is obtained when a dispersion of 'lne particle size is used.
• Aqueous dispersions having an average particle size of l-Z microns or less have given excellent results in practice, and therefore we recommend the addition of the impregnating agent in the form of an aqueous dispersion having at most this particle size.
• the flocculation' of the impregnating agent and its adsorption by the cationic resin-treated cellulose fiber is fairly rapid, and the standing time of the mixture after the impregnating' agent has been added makes very little difference in the resin retention.
• the stock can therefore be formed immediately after the addition of the impregnating agent or after a considerable period of time, as desired.
• the optimum quantity of the urea-formaldehyde resin that should be used to obtain the best retention of a dispersed or emulsied resin, wax, or other impregnating agent may vary with the nature and particle size of the dispersion, the nature of the cationic resin, the time of contact between the pulp ⁇ fibers and the .cationic resin solution, the pH of the stock and other factors. Also. because of the properties of vthe dispersed ⁇ accuses material added ⁇ and thev requirements of the finished-sheet or-article to be made, it maybe desirableto modify the proportion of urea-formaldehyde resin in order to obtain increased properties thereof 'in the finished product. In generaL'the proper amount of urea-formladehydeA resin.
• the optimum quantity of cationic resin is within the range of about 1 %-1.0%., based on the'weight of resin solids in the' impregnating agent. With'smallerquan'tities of impregnating agent such as 5%50% on the Weight of the cellulose," larger quantities of the cationic resin should be used.
• the principles of the invention may be applied in a wide variety of fields of paper making, molding, laminating, extruding, preforming and the like and in general Wherever a fibrous ⁇ cellulosic material intimately associatedwith thermoplastic, thermosetting, waxy, bituminous or other type of bonding,impregnating or coating material is .desired.
• Bleached kraft pulp, at a Green freeness of 475 andapproximately 1.5% consistency l was treated with various amounts of the above resin, as set forth in the table below, rand allowed-to stand for several hours at a pH of 4.0-5.0.
• the slurry was then adjusted to a pH of about 6.5 with dilute sodium hydroxide and a polystyrene emulsion, equivalent to 100% on polystyrene solids, of the dry fiber weight was added to the slurry Which'was then stirred for'15-'30 minutes. Thereafter, the slurry Was diluted to 1% liber consistency.
• Handsheets were'then made on a Williamsfreeness tester employing approximately 200 cc. of the fiber-resin suspension for each 10 sheet.
• The. polystyrene used inthis and the other illustrative examples was prepared as follows: 1.2 parts by Weight of sodium lauryl sulfate were dissolved in 58.8 parts of Water heatedv to l94 C. and 0.05 part of 40% hydrogen peroxide were added. 40 parts of styrene were then introduced uniformly over 1.5 hours,'with agitation sufficient to cause emulsication thereof. The exothermic polymerization reaction proceeded smoothly vand Was complete after .3.5 hours. Steam was blown through the batchl to remove unpolymerized material and the dispersion was adjusted to 25% solids.
• Example 3 Afresin syrup wasl prepared in the same Way as in Example 2 employing 11.25. grams of urea, 131 grams of 37% 'formaldehyde solution and 47 grams of tetraethylenepentamine.
• Example 5 vExample ⁇ 6 60 grams of urea were dissolved in 202 grams of 37% formaldehydesolution and the pH was adjusted to 8.5 by the addition of sodium hydroxide solution. The mixture was heated at. 70 C'. for 15 minutes and thereafter 1 ml. of concentrated hydrochloric acid Was added, followed by the addition of 24 grams of ethanoldiamine added as the hydrochloride. The mixture was heated at 70 C'. for 1 hour and the reaction mixture was thereafter neutralizedk With sodium hydroxide solution.
• a method of making a formed cellulosic product by the steps of preparing an aqueous suspension of fibrous cellulosic material, impregnating the cellulosic material with a waterinsoluble hydrophobic organic impregnating agent and forming the impregnated cellulosic material into a felted product, the improvement which consists in first adding a partially polymerized hydrophilic cationic urea-formaldehydepolyfunctional organic nitrogen base resin to the aqueous fibrous suspension, said cationic resin being formed by the condensation of a ureaformaldehyde reaction product with a watersoluble polyfunctional organic nitrogen base under acid conditions, then adding an aqueous dispersion of the organic impregnating agent in deflocculated condition and thereby immediately occulating the impregnating agent in the cellulosic fibrous suspension by the action of the cationic urea-formaldehyde-polyfunctional organic nitrogen base resin, and thereby depositing a
• a method of impregnating brous cellulosic material with an organic impregnating agent while preserving the freeness and felting properties thereof which consists in preparing a water suspension of the fibrous cellulosic material at 0.5%-6% consistency, adding to'said suspension a cationic urea-formaldehyde-polyfunctional organic nitrogen base resin in amounts of 1-l5% of the Weight of the fibrous cellulosic material, said cationic resin being formed by the condensation of a urea-formaldehyde reaction product with a Water-soluble polyfunctional organic nitrogen base under acid conditions, aging the suspension in non-alkaline condition for at least 30 minutes, then adding an aqueous dispersion of the organic impregnating agent in deocculated condition, thereby immediately fiocculating'the impregnating agent in the cellulosic fibrous suspension by the action of the cationic urea-formaldehyde-polyfunctional organic nitrogen base resin, and thereby depositing a substantial proportion of the
• a method of impregnating brous cellulosic material with 50-100% of its weight of an organic impregnating agent while preserving the freeness and felting properties thereof which -consists in preparing a water suspension of the fibrous cellulosic material at 0.5-6% consistency,
• a partially polymerized hydrophilic cationic urea-formaldehyde-polyfunctional organic nitrogen base resin in amounts of about 1%-15% of the Weight of the brous cellulosic material, said cationic resin being formed by the condensation of a ureaformaldehyde reaction product with a watersoluble polyfunctional organic nitrogen base under acid conditions, aging the suspension in a non-alkaline condition for at least 30 minutes, then adding the requisite quantities of an aqueous dispersion of the organic impregnating agent in deflocculated condition, thereby immediately occulating the impregnating agent in the cellulosic fibrous suspension by the action of the cationic urea-formaldehyde-polyfunctional organic nitrogen base resin, and thereby depositing 50-100% by weight of thev impregnating agent on said bers.
• hydrophobic organic impregnating agent is a polystyrene resin.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Wood Science & Technology (AREA)
• Materials Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Paper (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

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Citations (21)

• 0
  • BE BE486256D patent/BE486256A/xx unknown
  • NL NL73394D patent/NL73394C/xx active
• 1947
  • 1947-12-26 US US794116A patent/US2601598A/en not_active Expired - Lifetime
• 1948
  • 1948-11-30 FR FR975701D patent/FR975701A/fr not_active Expired
  • 1948-12-07 CH CH282395D patent/CH282395A/fr unknown
  • 1948-12-16 GB GB32566/48A patent/GB654955A/en not_active Expired
• 1950
  • 1950-09-29 DE DEA3765A patent/DE851162C/de not_active Expired

Patent Citations (22)

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