DE1134353B - Process for making a non-woven fiber product - Google Patents

Description

Method of Making a Nonwoven Fiber Product The invention relates to a process for the production of a non-woven fiber product or fleece, in which the fibers in a random position with a linear addition polymer of monoethylenically unsaturated Compounds are arrested under polymerization.

Such bonded nonwovens are used in the manufacture of a wide variety of flat or three-dimensional objects, including insulating material and the like, valuable. "Fiber fleece" is understood to mean a random arrangement of fibers, although there is often a partial orientation in a carded web.

It is known to use natural rubber latex to join the nonwovens and aqueous dispersions of synthetic rubbers, such as with styrene, acrylonitrile etc. copolymerized butadiene, but there are various Disadvantages, such as B. a strong coloration of the products and their poor resistance to ultraviolet radiation. In addition, a rubber-like handle is produced. It is also known to use nonwovens in which the fibers are in a random position, to connect with the help of certain polyvinyl compounds. The British patent specification 732 980 describes the use of polyvinyl chloride, according to the British patent 705 057 are used polyvinyl acetate emulsions and according to the Swiss patent 288,511 Thermosetting Condensation and Polymerization Resins. U.S. Patent 2689199 describes the manufacture of fiber products from thermoplastic fibers Character and the fusion of these fibers at certain points. If binder made of polyvinyl acetates, chlorides or their copolymers are used, the handle becomes paper-like, i.e. that is, the product shows a wrinkled, brittle appearance Handle and appears thin and brittle. The use of thermoplastic polymers like simple esters of acrylic or methacrylic acid, provides products in which the The binder remains permanently thermoplastic and therefore increases when exposed to it Can change temperatures. The simple acrylic and methacrylic acid esters are also included due to poor adhesion to hydrophobic fiber types such as polyamide and vinyl resin fibers, Cellulose esters and polyesters such as polyethylene glycol terephthalate. Furthermore, when using many of these previously used binders, the products cannot be washed, cleaned or dry cleaned. They also have binders a strong tendency, during the drying of the fiber products, on which the dispersions have been applied to migrate to the surfaces.

It has been found that when using certain linear addition polymers, which contain hydroxyl groups and which are applied by means of an aqueous system can avoid the disadvantages mentioned above.

According to the invention, a water-insoluble copolymer composed of at least 3% of a compound of the formula serves as the binder CH2 = CH-AR-OH (A = oxygen or sulfur and R = a straight-chain or branched alkylene group with 2 to 10 carbon atoms or a - (CnHznA) mCnH2n group, n = an integer from 2 to 4, m = an integer from 1 to 5) and a further monomer, the binder being crosslinked to the insoluble and infusible state and being contained in the product in an amount of 2 to 400% of the weight of the fibers. As monomers of the formula CHZ = CHAROH, z. B. are used: ß-Hydroxyethyl vinyl sulfide ß-Hydroxyäthylvinyläther 3-Hydroxypropylvinylsulfid 5-Hydroxypentylvinylether 6-Hydroxyhexylviiiyläther 8-Hydroxyoctylvinylether 10-Hydroxydecylvinylether thiodiglycolmonovinylether the use, of which it is not necessary to use Hydroxyethylsulfinyls, of which, thiodiglycol monovinyl ethers, of which, it is not necessary to use hydroxyethylsulfinyl ether, thiodiglycol monovinyl ethers of which, from which it is not necessary to use hydroxyethylsulfinyl ether, thiodiglycol monovinyl ethers of which, if it is not necessary for water-soluble homopolymers are obtained to use a water-insolubilizing comonomer.

The binder preferably contains 3 to 30 ° / a of compound C HZ = C H - A - R - OH.

The molecular weight of the polymers should be between about 100,000 and 10,000,000.

The comonomers can be chosen so that they are suitable for the binder give different properties. You can e.g. B. a soft and pliable one Binder or a hard and rigid binder form the bonded fiber product gives a corresponding rigidity.

This gives comonomers of the formula where R 'is hydrogen or the methyl group and Rx, when R' is methyl, is a primary or secondary alkyl group with 5 to 18 carbon atoms or - when R 'is hydrogen - an alkyl group with not more than 18 carbon atoms and preferably 2 to 12 carbon atoms, soft polymers.

Alkyl methacrylates with no more than 4 carbon atoms in the alkyl group, also tert-amyl methacrylate, tert-butyl or tert-amyl acrylate, cyclohexyl or Benzyl acrylate or methacrylate, acrylonitrile or methacrylonitrile, styrene, Vinyl chloride, chlorostyrene, vinyl acetate, acrylic acid amide, methacrylic acid amide, p-methylstyrene, Methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, sec: butyl methacrylate and tert-butyl methacrylate produce hard polymers.

It may be useful to copolymerize the hydroxyl-containing monomer with a mixture of two or more different monomers, one or more of which belong to the group forming hard polymers and another of which can belong to the group forming soft polymers. An example of this is a copolymer of 8 to 5501, ethyl acrylate, 44 to 90% methyl methacrylate and about 3 to 6% β-hydroxyethyl vinyl ether.

The polymers used as binders according to the present invention can also be graft or block copolymers, one or more of the Monomers, but not all, polymerized first and then another monomer or more are copolymerized with the copolymer obtained first.

The binder of the invention may further contain the hydroxyl-containing one Polymer heat-curable aminoplast condensates, e.g. B. from urea or Melamine or the like and formaldehyde, and to accelerate the condensation of the aminoplast product to an insoluble and infusible state The catalyst serves simultaneously and / or cooperatively to harden the hydroxyl-containing one Polymer.

The use of an aminoplast condensate in conjunction with the binders the invention serves to modify the handle and possibly increase the strength and resistance to wrinkling, pinching, and wrinkle formation.

Serving as an auxiliary binder aminoplast condensate can in a Amount of up to 25 percent by weight, preferably 2 to 11 percent by weight, of the Hydroxyl group-containing polymer are used.

These hydroxyl-containing polymers are unusual in that they compared to common organic solvents that are used in dry cleaning as well as other cleaning processes through simple hardening elevated temperatures, preferably between about 110 and 350 ° C or even up to 400 ° C or above for about 1 to 5 minutes at the higher temperatures and up to about 30 minutes or more at the lower temperatures will. Under such conditions, other hydroxyl-containing polymers, z. B. those that are the same in every other respect, but hydroxyl-containing Have groups consisting exclusively of hydroxyethyl or hydroxypropyl acrylates or methacrylates, no solvent or washing resistance.

The binders used according to the invention contain a large number of hydroxyl groups, affecting their ability when heated with or without catalysts to become insoluble and infusible is due. The hardened or tempered Product therefore shows improved resistance to cleaning, dry cleaning and stain removal, against various chemicals and heat. According to the invention The nonwovens obtained can be heated to a significantly higher temperature than the previously known products made with the above-mentioned binders, without discolouring, becoming brittle or suffering from detrimental decomposition. The nonwovens show excellent ironing resistance, but they do not how the previously used thermoplastics become sticky. The hydroxyl groups also seem to produce more versatile adhesion, because the binders of the present invention not only by good adhesion to hydrophilic ones Fibers such as cotton, regenerated cellulosic rayon and the like., Characterized are, but also by an excellent adhesion to hydrophobic fiber types, such as polyamide resins, vinyl resins such as copolymers of vinyl chloride with vinyl acetate or acrylonitrile, polymers of 70 to 90% acrylonitrile and others Monomers such as vinyl chloride, Vinyl acetate, one of the vinyl pyridines such as 2-vinylpyridine or a mixture of such additional monomers, polyesters such as poly (ethylene glycol terephthalate) and cellulose esters such as cellulose acetate, cellulose acetate propionate, Cellulose acetate butyrate, etc.

The binders used according to the invention have good adhesiveness even on silica-like fibers that have hitherto been colorless because of the difficulty To find binders that are sufficient on the silicic acid-like material, such as. B. glass fibers, adhere, were difficult to process. Because of the characteristic Adhesion of the binder of the present invention to both hydrophilic as well as on hydrophobic fibers, the fiber products are excellent Marked for resistance to abrasion. The fiber products with the invention Binders also have the advantage that they are in the moist state or during the first drying, but before it is completely dry, be permanently embossed can.

The hardened or insolubilized binders are made by water or organic solvents, such as. B. styrene, even at deformation temperatures not attacked, which is why the connected fiber products are used as preforms or mold inserts in the manufacture of molded articles from various heat curable Resins can be used as described in more detail below. The binders also show no cold flow and are also at elevated temperatures flow resistant, causing a displacement of the fibers or threads in the connected Products is made impossible even at elevated temperatures.

The fibers are in the form of a so-called "non-woven" fleece before, in which they are distributed completely randomly. The fleece can be produced by carding when the fibers are so designed in their length and flexibility that they enable carding. The fleece obtained from a card can be treated directly but it is generally advisable to lay several such fleeces on top of one another, so that mats of the required thickness are obtained. To produce such mats you can superimposed layers of carded nonwovens are placed so that their fiber orientation directions rotated by 60 or 90 ° with respect to those of the neighboring layers.

Mats can also be made by depositing natural or artificial Fibers are made from a stream of air.

The binder of the invention is in the form of an aqueous dispersion applied by emulsion copolymerization of the hydroxyl-containing monomers can be prepared with the other monoethylenically unsaturated comonomers.

The binder used is preferably an aqueous dispersion with a content of 2 to 60 percent by weight of the water-insoluble copolymer upset. A concentration of 20 to 40 percent by weight is best.

The binder can also be applied as a powder. Farther you can apply the binder dispersion or the powder to the fibers, if these fall through a settling chamber to the place where they were deposited.

Regardless of whether there is an aminoplast condensate in connection with the Hydroxyl group-containing polymer is applied or not, the system - either in the aqueous dispersion of the polymer or by separate application on the fiber fleece before or after the application of the aqueous dispersion of the polymer - A catalyst can be added to the hardening of the binder (implementation of the Hydroxyl groups). The catalyst can be used in an amount up to 2 %, Preferably about 0.5 to 1 percent by weight, based on the polymer, added will. The catalyst can be chosen so as to avoid undue impairment of the fibers used in the respective fiber product is avoided, but it is in any case an acidic or acid-forming substance, the latter being latent Catalyst works and releases acid when heated. When hardening is likely to occur a bond with reactive groups, e.g. B. in cellulose fibers the hydroxyl groups of cellulose.

The quantity ratio of binder to fiber component can vary, depending on the type of product required. For the production of preforms that are to be converted into shaped objects, are preferably 2 to 10 "/, Binder, based on the weight of the fibers, applied. For the production of insulating compounds, the amount of binder used can be in the lower part of the just specified range when the binder is mainly on the surface or the surfaces of the product is applied or when it is in conjunction with other binders is used.

When the main purpose of the binder is to bind the fibers together to connect to a coherent unified structure, in which the largest possible Porosity combined with a minimum change in the natural fiber grip should be maintained, 2 to 50 percent by weight of solid binder, based on the fiber. The products thus obtained are for sanitary Purposes valuable, e.g. B. as napkins, bibs, tablecloths, medical mouth towels, Towels or diapers, bandages and compresses to be destroyed after use. It is characteristic of the binder applied in the proportions just given, that there is virtually no or no "windowing" at all, d. H., the spaces between the fibers remain open, so that a highly porous, loose Product is formed. Of course, the density of the product can be increased by compressing it before or in many cases even after curing the product.

Nonwoven fiber products for which 40 to 150 percent by weight binder, based on the weight of the fiber, are usually very valuable for clothing purposes, e.g. B. as inner clothing for skirts, suits, etc. or as Outerwear fabrics, e.g. B. for blouses, skirts, shirts, etc. The items of clothing these fabrics do not need to be ironed or mangled to get their appearance, their shape and their grip after hand washing, machine cleaning or dry cleaning restore. Except for the general uses mentioned above in the home and for clothing, fiber products containing 2 to 100 percent by weight can be found Binders on a fiber basis contain extensive industrial use as Wipes, lining materials for packaging, being filters, seals and packs for technical purposes.

Fiber products of the invention in which 100 to 400 percent by weight Binders used based on the weight of the fiber are particular valuable for technical purposes where they are highly stressed and durable and must be wear-resistant, e.g. B. for seals, filters, etc. The products, the 20 to 200 "/, of the binder of the present invention, by weight of the Fiber-related, included, are as sub-layers, i. H. as intermediate layers or as backing layers, for plastic films and foils, e.g. B. made of polyethylene, polyamide etc., or in connection with woven, braided, knitted, knotted or Felted textile fabrics can be used.

The fiber mats connected according to the invention can also be used as heat or sound insulation, as permeable membranes z. B. in batteries or electrolytic capacitors, serve as a cushion or cushioning material for upholstery purposes, etc.

The following examples illustrate the invention. Unless otherwise stated, all parts and percentages are units of weight. Example 1 a) A carded fleece made from 75 parts of viscose (staple fibers of 3 denier and 2.54 cm in length) and 25 parts of cotton (medium quality, 2.38 cm in length), weighing 25 g / m 2, is impregnated with an aqueous dispersion , the 100 parts 25.0 parts of an emulsion copolymer of 7.5% ß-Hydroxyäthylvinylsulfid and 92.5% butyl acrylate, 2 parts of tert-octylphenoxy polyethylene, which contains about 35 oxyethylene units (emulsifier and dispersant), 0 Contains, 4 parts octylphenoxyethoxynatriumsulfat (wetting agent), 0.1 part silicone as an antifoam agent, the fibers absorbing 600 ″ of their weight on a wet basis. The fleece is dried for 1.5 minutes at 107 ° C. and 1.5 minutes cured at 177 ° C. The nonwoven cloth obtained contains fiber and binder in a proportion of about 80:20. It is very porous and has a soft and elastic feel.

b) The procedure of part a) is repeated with Pyrex glass fibers, only the carded fabric weighs about 17 g / m2, and the impregnation with the aqueous dispersion is carried out on a wet basis up to an absorption ratio of 300%, which means results in a fiber to binder weight ratio in the finished sheet of 53:47 . The product is extremely porous and soft and yet sticks together.

Example 2 A carded fleece made entirely of viscose (staple fibers 5 denier and 3.2 cm in length), which weighs about 68 g / m2, is made with a pattern a large number of rings are printed at intervals with an aqueous dispersion which for every 100 parts 25.0 parts of an emulsion copolymer composed of 10 parts of ß-hydroxyvinyl ether, 20 parts of butyl acrylate and 70 parts of ethyl acrylate, 2 parts of tert-octylphenoxypolyethoxyethanol, which contains about 35 oxyethylene units (emulsifier and dispersant) and sufficient Methyl cellulose to achieve a Brookfield viscosity of about 2000 centipoise at 24 ° C (measured with spindle no.3 at 30 rev / min.). The fleece will Dried at 116 ° C for 1 minute and cured at 149 ° C for 2 minutes. The resulting nonwoven cloth contains fibers and binders in a proportion of about 80: 20. The fleece is held together by the bound rings and is through and by porous.

EXAMPLE 3 The process of Example 1, a) is repeated with an aqueous dispersion of an emulsion copolymer composed of 300% diethylene glycol monovinyl ether and 700 % ethyl acrylate. A coherent, bound fleece with a soft feel is obtained, which can be used as a table napkin.

Example 4 Contiguous, bonded nonwovens with soft, textile-like Handle will be carded by repeating the procedure of Example 1, a) with similar Nonwovens obtained with the following composition: 1. 50% polyamide and 50% cellulose acetate, 2. 50% viscose rayon with 50% polymer of about 85 to 90% acrylonitrile, 3. 55% polyamide and 45% viscose rayon, 4. 100% cotton (card waste, Roving and yarns), 5. 1000 /, polyamide, 6. 1000 /, viscose rayon (staple fibers 5 denier and 3.8 cm) and 7. 35% cotton and 65% poly (ethylene glycol terephthalate).

Example 5 The procedure of Example 1, a) is carried out with 25 parts of a Emulsion copolymer of 7.5% 5-hydroxypentyl vinyl ether and 92.5% n-butyl acrylate repeated instead of the copolymer used there. A similar one, strong porous, but cohesive, non-woven fleece with a soft and elastic Grip is preserved.

Claims (3)

CLAIMS: 1. A method for producing a non-woven fiber product wherein the fibers are arrested in random orientation with a linear addition polymer of monoethylenically unsaturated compounds to bring the polymerization, data carried in that as binder a water insoluble copolymer of at least 3 ° / o of a compound the formula C HZ = CH -AR-OH (A = oxygen or sulfur and R = a straight-chain or branched alkylene group with 2 to 10 carbon atoms or a crosslinked and infusible state and should be contained in the product in an amount of 2 to 400% of the weight of the fibers. 2. The method according to claim 1, characterized in that the binder 3 to 30 "/, which contains compound C HZ = C H - A - R - O H. 3. The method according to claim 1, characterized in that the binder is used as an aqueous dispersion with a content of 2 to 60 percent by weight of the water-insoluble copolymer. - (C. HZ. A). Batch group n = an integer of 2 to 4, m = an integer from 1 to 5) and another monomer is used, wherein the binder to the insoluble Contemplated publications: USA. Patent No. 2,689,199. ; British Patent Nos. 705 057, 732 980; Swiss patent specification No. 288 511.