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
  • 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
  • D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
  • D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
  • D21H17/45—Nitrogen-containing groups
  • D21H17/455—Nitrogen-containing groups comprising tertiary amine or being at least partially quaternised
• • 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
  • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
  • D21H13/36—Inorganic fibres or flakes
  • D21H13/38—Inorganic fibres or flakes siliceous
  • D21H13/40—Inorganic fibres or flakes siliceous vitreous, e.g. mineral wool, glass fibres
• • 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
  • D21H17/37—Polymers of unsaturated acids or derivatives thereof, e.g. polyacrylates

Definitions

• binders In the production of flexible fabrics such as paper, cardboard and non-woven fabrics from fibers by wet means, binders must be used in order to achieve sufficient strength.
• binders are often used in the form of aqueous dispersions which the pulp '. added and precipitated at a later stage.
• the quality of the binders has primarily been subject to requirements from a manufacturing point of view.
• the degree to which the binders or the polymeric components are used generally plays an important role from an ecological and commercial point of view.
• the focus of interest was the needs and requirements of the paper industry.
• DE-AS 12 09 867 specifies a process in which, before dewatering, the anionic and cationic, thermoplastic plastics (latices) are added to the aqueous, optionally ground pulp slurry, one after the other, by known incorporation and / or polymerization of ionic compounds electrically neutral monomers are anionic or cationic.
• DE-OS 26 1.9 310 proposes conversely, by adding an anionic, water-soluble hydrophilic polymer - preferably poly (meth) acrylic acid, polymeric itaconic acid - and / or salts thereof before adding the polymer latex, which can be quite conventional, to separate the latex for fiber suspension.
• Alum must be added to the fiber slurries (except in the case of asbestos).
• the water-soluble polymers should contain more than 60% by weight of acid and less than 40% by weight of other copolymerizable monomers.
• US Pat. No. 2,995,512 teaches the clarification of colloidal aqueous dispersions by adding water-soluble cationic polymers to anionic disperse phases and vice versa.
• DE-OS 27 10 966 an anionically stabilized aqueous dispersion of a carboxyl group-containing resin with a carboxyl group content of at least 6 wt.
• DE-OS 27 10 996 also gives indications that — by means of the composition of the binder and the amount of binder, the mineral fiber papers that can be produced according to the application can be made either hard and rigid or soft and pliable.
• the primary manufacturing requirements primarily the 100% separation of the binder on the mineral fibers, are also largely met.
• the present invention has for its object to provide a method that gives mineral fiber-based fabrics good tear and splitting strength as well as flexibility and kink resistance. In addition, sufficient initial wet strength, good drainage and clear waste water with the lowest possible foam tendency are expected.
• R 1 is an alkyl radical having at least 2 carbon atoms, preferably 4 to 18 Carbon atoms and optionally crosslinkable polymerizable monomers and optionally copolymerizable monomers, especially those with an influence known as "film-curing" on the overall polymer, to a lesser extent.
• acrylic esters of the formula I in which R 1 is a C 4 radical, such as isobutyl or in particular n-butyl, or in which R 1 is 2-ethylhexyl, or mixtures thereof.
• the proportion of the acrylic ester of the formula I is at least 50% by weight, based on the total polymer, preferably in the range from 60 to 95% by weight, particularly preferably in the range 70-93% by weight.
• the proportion of crosslinkable monomers in the cationic acrylic dispersion is such that a sufficient crosslinking effect occurs in order to prevent the film from blocking at high temperatures or high air humidity.
• crosslinkable monomers In general, the proportion of crosslinkable monomers does not exceed a value of 15% by weight, based on the total polymer in the cationic dispersion. As a standard value e.g. a content of 3 to 10 wt .-% can be considered.
• crosslinkable monomers are to be understood primarily as self-crosslinking systems.
• Suitable self-crosslinking monomers are primarily, for example, those with an N-methylolamide or ether, along with nitrile and carboxyl groups.
• N-methylolacrylamide N-methylolmethacrylamide, N-alkoxymethylacrylamide and N-alkoxymethylmethacrylamide, for example N-athoxymethyl methacrylamide and N-butoxymethyl methacrylamide.
• N-methylol methacrylamide is preferred, optionally in combination with methacrylamide.
• self-crosslinking monomers also come with two or more reactive double bonds in the molecule, for example glycol dimethacrylate, 1,4-butanediol dimethacrylate, ethylene dimethacrylate, triglycol dimethacrylate, trimethylolpropane trimethacrylate or allyl compounds such as allyl methacrylate or allyl cyanurate, triallyl cyanurate and the like.
• the monomers which can be copolymerized in smaller proportions, especially those with an influence on the overall polymer known as film-hardening, generally make up between 0 and 40% by weight, preferably between 0 and 30% by weight, based on the polymer content of the cationic acrylic dispersion .
• the film can be given increasing hardness depending on the requirements.
• copolymerizable monomers examples include esters of methacrylic acid with C 1 to C 4 alcohols, styrene, ⁇ -methylstyrene, vinyl chloride, vinylidene chloride, vinyl esters of fatty acids, such as vinyl acetate, vinyl propionate. If necessary, flame retardant additives can also be added to the agents according to the invention in minor amounts.
• water-soluble polyanionic compounds are suitable as precipitants (cf. Ullmann's Encyclopedia of Industrial Chemistry, 4th edition, vol. 11, pp. 581-586, Verlag Chemie).
• examples include polymers or copolymers of acrylic acid, in particular with electrically neutral monomers, especially with acrylamide, in the form of suitable salts, for example the sodium salt, and also those of methacrylic acid and maleic acid.
• the average molecular weight is usually 5-10 million.
• copolymers of acrylic acid with acrylamide in the form of their sodium salts are suitable.
• the preparation of the polymers which are used according to the invention can be carried out in a manner known per se, e.g. done in emulsion polymerization in water. (See H. Rauch-Puntigam, Th. Völker, "Acryl- und Methacryl -educationen; Springer-Verlag 1967).
• the procedure can be carried out according to the one-pot ("batch") or preferably according to the monomer feed or emulsion feed process.
• water, emulsifier and initiator water-soluble initiators such as hydrogen peroxide, perborate, persulfate and azo compounds
• emulsion feed process an emulsion is first prepared from monomers, water, emulsifier and initiator and part of it is heated in the polymerization kettle. After the onset of polymerization, the remaining emulsion is slowly metered in from the feed tank.
• emulsifiers e.g. Salts of long-chain amines in amounts of normally 0.5-6% by weight, based on the amount of water, are used.
• the method according to the invention can be carried out based on the known methods of technology:
• Mineral fibers such as glass fibers or rock wool and their mixture with glass fibers, as well as asbestos and mixtures with natural fibers such as cellulose fibers, for example fibers obtained from waste paper and fiber waste and textile fibers themselves, are particularly suitable as carrier fibers for the flexible sheetlike structures of the invention.
• the fiber thickness is usually in the range of 5 - 20 ⁇ m, the fiber length is generally 3 to 7 mm. Shorter fibers result in fabrics of lower strength.
• the dry fiber can be suspended, for example, with about 100 times its weight in water.
• the amount of binder depends on the requirements. Binder contents of 2.5-10% by weight, calculated as the dry weight of the binder resin, based on the dry weight of the fibers j , already meet the stated requirements in many cases. However, the proportion of binder can also be increased up to about 100% of the fiber weight. Methods for producing cationic dispersions are known.
• the cationic acrylic dispersions used according to the invention generally contain 10-60% by weight, preferably about 30 to 55% by weight, of binder in the aqueous phase which contains a cationic dispersant.
• non-ionic dispersants are generally between 0.5 and 6% by weight in the water phase.
• non-ionic dispersants can also be used in an amount of about 1-3% by weight will.
• Compounds with a surfactant character are preferably used as nonionic dispersants, such as oxyethylated fatty acids, fatty alcohols or alkylphenols, but also protective colloids such as polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone or polyalkylene oxides and block copolymers of ethylene oxide and propylene oxide are suitable.
• the cationic acrylic dispersion diluted to the appropriate solids content, is metered into the fiber suspension and evenly distributed for a certain time, about 3-5 minutes.
• the anionic precipitant in aqueous solution is then expediently metered in with stirring.
• the suitable amount can usually be easily determined by preliminary tests.
• the concentration of the flocculant can be of the order of magnitude ⁇ 1% by weight. Shortly after the precipitant is evenly distributed in the mass, the binder is completely deposited on the mineral fibers. After the precipitation, the serum is completely clear. You can also add the precipitant and then the binder to the fiber-water mixture.
• the fiber-water mixture can now be used in the usual way
• the draining water is clear and practically free of binders.
• the fabric thus obtained is introduced into a drying zone, where the crosslinkable binder also hardens.
• the mineral fiber-based fabrics obtained according to the invention can be used, for example, as filter material or for production of largely chemical and heat resistant protective suits. They mainly serve as a carrier layer for various types of coated materials, such as rot-resistant bitumen cardboard, plastic floor coverings or synthetic leather-like materials.
• Example 1 50 g of dry rock wool fibers (length 3 - 5 mm) are suspended in 10 l of water. 30 g of the dispersion of Example 1 diluted to 25 fat content are added to this suspension After approx. 1 min. 8.5 ml of a 0.2% solution of a copolymer of acrylamide and the Na salt are added to this suspension. added to the acrylic acid (commercial product PRAESTCL® 2935/73), whereby flocculation occurs. Then 2000 ml of this substance / water mixture are dewatered on a sieve (No. 0.100 DIN 4188), a clear waste water being obtained.
• the flexible stone wool fleece obtained has a weight per unit area of approximately 320 g / m 2.
• the flexible fabrics manufactured according to the invention largely meet the requirements mentioned at the beginning. They are characterized by high flexibility with very good strength properties. The process is particularly characterized by the rapid drainage and the absolutely clear wastewater obtained.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Paper (AREA)
• Porous Artificial Stone Or Porous Ceramic Products (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

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Citations (4)

• 1979
  • 1979-06-15 DE DE19792924085 patent/DE2924085A1/de not_active Withdrawn
• 1980
  • 1980-04-02 EP EP80101762A patent/EP0020884A1/fr not_active Withdrawn
  • 1980-06-13 JP JP7917480A patent/JPS564800A/ja active Pending

Patent Citations (4)

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