DE1815329A1 - Polyester impregnated fibre mats - Google Patents

Abstract

Impregnated sheets made from fibrous textiles containing 10-30 wt.% of a mixture of unsaturated polyester and a unsaturated polymerisable monomer of boiling point more than 50 degrees C and a photoinitiator in proportion 0.01-4 wt.% of the polyester/monomer. The product is crosslinked photochemically. The impregnating solution has unlimited pot life, and very short gelation time. Polymerisation can be interrupted if required.

Description

Methods of Making Nonwoven Fabrics The invention relates to a process for the production of nonwovens from nonwovens with a mixture made of an unsaturated polyester, with ethylene-unsaturated polyesters that can be polymerized onto it Monomers and a photoinitiator impregnated and then cured photochemically will.

It is known from nonwovens by means of natural or synthetic Produce polymer bonded sheet-like structures.

Such binders are, for example, solutions or dispersions of crosslinkable or vulcanizable polymers, such as natural or synthetic Rubber, used (cf.

DAS 1 014 957, German patent specification 906 568 and 864 845, Z.ges.

Textile ind. 64 (1962), page 590 ff.). In technology, in particular Aqueous plastic dispersions used as binders for nonwovens, wherein the fiber fleece is impregnated with the dispersion and then dried solidified and condensing to form a nonwoven (cf. DAS 1.159 384, DAS 1 135 412, DAS 1 135 413, DAS 1 086 208 and German patent specification 1 134 353).

These aqueous plastic dispersions, the copolymers very much may contain different composition, show against solutions of Polymers in organic solvents have significant advantages, such as simpler, physiologically harmless handling and less equipment required for drying, however, the auxiliaries required for production, such as emulsifiers, remain and protective colloids in the end product, increasing the resistance to cleaning of the nonwovens is decreased. In addition, the aqueous plastic dispersions migrate on drying impregnated nonwovens the binder particles in the capillary flow to the nonwoven surface, which leads to uneven fiber consolidation which-results in splitting of the nonwoven fabric noticeable during dry cleaning with organic solvents power.

It has now been found that the above-mentioned disadvantages are avoided and non-woven fabrics excellent in cleaning resistance will, if the nonwovens are produced by a process that is characterized is that the fiber fleece with 10 to 300 percent by weight, based on the fiber fleece, one Mixture of unsaturated polyester, at least one polymerizable olefinic unsaturated monomeric compound with a boiling point above 50 ° C and at least a photoinitiator in amounts vorl 0.01 to 4 percent by weight, based on the Polyester / monomer mixture, impregnated and then photochemically hardened.

The usual polycondensation products are suitable as unsaturated polyester resins from polybasic, in particular dibasic carboxylic acids, which with polybasic, in particular dihydric alcohols are linked in an ester-like manner, and optionally additional residues of monohydric carboxylic acids and / or residues of monohydric alcohols and / or Containing residues of hydroxycarboxylic acids, with at least some of the residues above Ethylenically unsaturated copolymerizable groups must have. These unsaturated Polyesters are usually made by melt condensation or condensation under azeotropic conditions made from their components.

It has proven to be useful in general if the unsaturated Polyester has an acid number of 5 to 70, preferably 25 to 45, and a medium one Have molecular weights of from about 800 to 4,000.

As polyvalent, especially divalent, optionally unsaturated Alcohols are the usual, especially acyclic groups, cyclic groups, as well as both types of alkanediols containing groups, such as ethylene glycol, propylene glycol (1,2), Butylene glycol (1,3), butanediol (1,4), hexanediol (1,6), 2,2-dimethylpropanediol ( 1,2), diethylene glycol, triethylene glycol, cyclohexanediol (1,2), 2,2-bis (p-hydroxycyclohexyl) propane, Neopentyl glycol, 1,4-bis-methylolcyclohexane or 1,4-butenediol. Furthermore, one, trihydric and higher alcohols, such as benzyl alcohols, 1,2-di- (allyloxy) -propanol- (3), Glycerine, pentacrythritol or trimethylolpropane are also used in subordinate amounts will.

The polyhydric, especially dihydric alcohols are generally in stoichiometric or approximately stoichiometric amounts with polybasic, in particular dibasic carboxylic acids or their condensable derivatives implemented.

Suitable carboxylic acids and their derivatives are olefinic dibasic ones unsaturated carboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid and mesaconic acid or its anhydrides. - In the polyester you can continue to use additional other dibasic unsaturated and / or saturated carboxylic acids, such as succinic acid, Glutaric acid, Z-methylglutaric acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, Terephthalic acid, 1,2j3,6-tetrahydrophthalic acid, 3,6-endomethylene-1,2,3,6-tetrahydrophthalic acid, or their choir substitution products, e.g.

2,3,4,5,7,7-hexachloro-2,5-endomethylene-1,2,5,6-tetrahydrophthalic acid, be condensed, furthermore mono-, tri- and higher basic carboxylic acids, such as e.g. Propionic acid, 1,2,4-benzene tricarboxylic acid or 1,2,4,5-benzene tetracarboxylic acid.

Unsaturated polyesters of this type are preferably composed of about 0.8 to 2.4 moles of maleic acid and 0.8 to 2.4 moles of phthalic acid and about 1.6 to 4.8 Mol of ethylene glycol and / or 1,2-propylene glycol or from approximately molar amounts of 2,3,4,5,7,7-hexachloro-2,5-endomethylene-1,2,5,6-tetrahydrophthalic acid and butanediol- (1,4).

As polymerizable olefinically unsaturated monomers with a boiling point of over 500C, all customary copolymerizable with unsaturated polyesters are suitable monomeric compounds, in particular (meth) acrylic and vinyl compounds, such as esters acrylic acid or methacrylic acid with alcohols with 1 to 8 carbon atoms, such as ethyl acrylate, butyl acrylate, methyl methacrylate or Glycol dimethacrylate, amides, N-methylolamides or etherified N-methylolamides or Nitriles of X, ß-unsaturated tlonocarboxylic acids5 such as acrylamide, methacrylamide, N-methylolacrylamide, N-butoxymethyl methacrylic acid amide, acrylonitrile or methacrylonitrile, Vinyl esters of mono- and polycarboxylic acids, such as .B. Vinyl acetate, vinyl propionate or divinyl succinate, N-vinyl compounds, such as N-vinylpyrrolidone, Vinyl ethers of mono- and polyoxy compounds, such as isobutyl vinyl ether, or Butanediol (1,4) divinyl ether. Allyl compounds, such as allyl esters, are also suitable of saturated or unsaturated mono- or polycarboxylic acids or of inorganic acids Acids such as diallyl phthalate, diallyl maleate, triallyl cyanurate or triallyl phosphate, as well as allyl ethers of i4ono- or poloxy compounds, such as glycol diallyl ether, Pentaerythritol tetraallyl ether, Tetramethylolaoetylenediureadiallyl ether and its still soluble condensation products. Vinylaromatic compounds such as styrene, alkyl and / or are particularly suitable Halogen-substituted styrenes, divinylbenzene, or vinylnaphthalene and O (-methylstyrene. Mixtures of the monomers mentioned are also suitable.

The composition of the mixture of unsaturated polyester and at least a polymerizable olefinically unsaturated monomeric compound can be broad Areas are changed. In general, the mixtures contain 20 to 70, preferably 30 to 60 percent by weight of olefinically unsaturated monomeric compounds and corresponding to 80 to 30, preferably to 40, percent by weight of unsaturated Polyester. These mixtures can also contain other unsaturated substances in minor amounts Polymers such as polybutadiene homo- and / or copolymers contain.

Compounds containing disulfide groups are used as photoinitiators, such as dialkyl, alkylaryl or diaryl disulfides, such as din-butyl disulfide, dibenzyl disulfide, Diphenyl disulfide, or 4> 4, -dimethyl-diphenyl disulfide, thiuram compounds, such as tetraalkylthiuram disulfide, such as tetramethylthiuram disulfide or tetra-ethylthiuram disulride, Dixanthates, such as dialkyl or diaryl or alkylaryldixanthates, such as e.g. Diethyl xanthate, diisopropyl xanthate, diphenyl dixanthate, or hexyl isobutyl dixanthate into consideration. Vicinal ketaldonyl compounds are also suitable as photoinitiators, such as diacetyl or benzil, i-ketaldonyl alcohols such as benzoin, acyloin ether, such as.

Benzoin methyl ether, aromatic substituted in the o (position. Aceloyle, such as (-Methylbenzoin aromatic ketones and aldehydes such as benzophenone, propiophenone or benzaldehyde, substituted anthraquinones such as ethyl anthraquinone. Particularly The acyloin ethers and mixtures of the photoinitiators listed are advantageous.

The photoinitiators are generally used in amounts from 0.1 to 4, preferably 0.1 to 3 percent by weight, based on the polyester / monomer mixture added.

The mixtures of unsaturated polyester, at least one olefinic unsaturated Compound and photoinitiator (s) can also be other in minor amounts common catalysts such as peroxides, common accelerators such as vanadium or contain C, obalt compounds and optionally fillers, insofar as they are dissolve in this mixture or its refractive index largely matches that of the mixture matches.

The polyester / monomer / photoinitiator mixtures can be used to increase the storage stability additional conventional polymerization inhibitors, such as monohydric or polyhydric phenols, e.g. hydroquinone, resorcinol, pyrocatechol or 2,6-di-tert-butyl-p-cresol, furthermore Copper compounds such as copper naphthenate and compounds with a similar effect in usual amounts of about 0.005 to 0.2 percent by weight, preferably 0.01 to 0.05 percent by weight.

While it is not possible to have one impregnated with just monomers Solidify fleece under the same conditions, as the oxygen in the air also occurs high photoinitiator concentrations cause the monomer to polymerize on the raw fleece is inhibited in the method according to the invention for producing nonwovens Exclusion of oxygen is not necessary. As with processing unsaturated Polyester resins are common, but skin-forming substances are also added, such as e.g. paraffin, an advantage for the polyester / monomer / photoinitiator mixtures (German Patent No. 94 & .a1).

The amount of skin-forming substances added is usually 0.01 to 0.3, preferably 0.05 to 0.2, percent by weight, based on the binder mixture.

The usual hardening of unsaturated polyesters with the help of peroxide / Amine or cobalt compounds. Must be carried out with a high starter concentration, if you want to set short, technically interesting setting and hardening times. At the same time, however, this shortens the pot life too much.

In contrast, the method according to the invention has the advantage that (with the exclusion of UV radiation) both an unlimited pot life and very short hardening and gel times, and photopolymerization at will can be interrupted.

In addition, the handling of the. Photoinitiators essential safer than the hardening systems that were photographed.

The mixtures are made from the individual components in common 'mixing units.

Fiber fleeces made from natural and synthetic materials are used as the substrate Fibers or their mixtures, such as wool, cotton, jute, nylon, polyester, Polyacrylonitrile, or inorganic fibers, such as glass fibers, into consideration. the The nature and manufacturing process of the substrate is essential for the process itself irrelevant.

Both the selection of the fiber fleece according to fiber type, fiber titre and fleece type, as well as the amount of polyester / monomer / photoinitiator mixture applied to the fiber fleece depends on the intended use for the nonwoven, e.g. according to the desired mechanical strengths and other properties.

The application of the polyester monomers / photoinitiator mixture to the The substrate can be processed using the usual methods, e.g. by impregnating the fiber fleece with this mixture and then removing the excess, e.g. by pressing between rollers or by spraying the mixture onto the nonwoven fabric.

The amount of polyester monomers / photoinitiator mixture with which the fiber fleece is impregnated, depending on what is intended for the fleece material Intended use between 10 and 300 percent by weight, preferably 30 to 200 percent by weight, based on the fiber fleece.

The light which triggers the polymerization can, for example, be a Have a wavelength of 2,300 to 4,500 A or a sufficient amount of light have this wavelength. In addition to sunlight, the UV light sources are preferably used the usual mercury-tungsten- and xenon lamps are considered, with both high and medium and low pressure lamps can be used, The method according to the invention is suitable particularly suitable for the production of voluminous nonwovens, especially so-called Fill-.

nonwovens that only solidify on the surface, the polyester / The monomer / photoinitiator mixture is sprayed onto the fiber fleece and then hardened by UV light. According to the process according to the invention, the web consolidation reached within a short time. In addition, the previously common ones are no longer applicable Process necessary removal of solvent or a drying process for Removal of water.

A migration of the binding agent partly dependent on the fiber material, such as fiber webs impregnated with aqueous plastic dispersions during drying show, and which is particularly pronounced in thick nonwovens, leads to unevenly solidified fleece monkeys that delaminate during dry cleaning. According to the invention Procedure, but independent of the type of fiber and the thickness of the nonwoven fabric, very evenly consolidated nonwovens.

If, for example, one produced by the method according to the invention is shaken If the nonwoven is in perchlorethylene for 30 minutes, it will remain at least 90 percent by area obtained, while nonwovens, those with usual applied for nonwoven bonding Aqueous plastic dispersions were prepared under the same conditions delaminate to at least 55 percent by area.

Another particular advantage of the method according to the invention is that it strengthens the web without the use of solvents and thinners enables.

The parts and percentages given in the examples are parts by weight or percentages by weight.

Example 1 A prepared according to the usual polycondensation technique Unsaturated polyester resin made from 2 moles of maleic acid, 1 mole of phthalic acid and 3 moles Propylene glycol-1,2 is dissolved 65% in styrene, with 0.1% paraffin of the melting point 500C and with 0.5% benzoin methyl ether offset. A nylon fleece with a surface weight of 60 g / m2 is impregnated with the above mixture in an immersion bath. The excess is then squeezed off between two rollers and the impregnated Fiber fleece then for 5 minutes with a UV light source in the wavelength range 3,500 - 4,000 A (e.g.

Philips-TLA 40/05 - lamp) exposed. The nonwoven fabric thus obtained proves to be very washable and dry-cleanable. The binder content is about 60% by weight, calculated on the weight of the raw fleece.

As proof of the very good dry cleaning resistance, the The fleece is shaken in trichlorethylene for 30 minutes. 90 percent of the area remains obtain.

Comparative experiment After the emulsion feed process, a 40% strength Aqueous dispersion of a copolymer of 79% by weight of n-butyl acrylate, 17 "methyl acrylate, 1.5" methacrylamide, 0.7 "methacrylic acid, and 2.0" N-methylol methacrylamide using 2% by weight, based on the monomers, of one anionic emulsifier. A nylon fleece with a basis weight of 60 g / m2 is impregnated with this dispersion, dried and condensed at 1500 for 15 minutes. The application of binding agent is 100% by weight, based on the weight of the raw material. The nylon nonwoven is shaken in 500 ccm of trichlorethylene for 30 minutes, with it breaks down into two layers, i.e. the cohesion of the area after the test O area percent.

Example 2 The polyester specified in Example 1 is used as a 50% strength Solution in a mixture of 70 parts of styrene and 30 parts of ethyl acrylate after adding 0.1% paraffin with a melting point of 50 ° and 0.3% benzoin methyl ether sprayed onto a cotton fleece. By Squeezing by rollers the application is brought to 130%> based on the mixture of the raw fleece. By exposing for 10 minutes to a UV light source (e.g. Philips-TLA 4O / O5 - Lamp) a nonwoven fabric with very good dry cleaning resistance is obtained.

Example 3 2 A polyester fleece (approx. 100 g / m) is made with 75% by weight, calculated on the weight of the raw fleece, binder from Example 1, instead of 1% diisopropylxanthogen disulfide of benzoin methyl ether is added after addition impregnated with 0.1% paraffin. By irradiating with the in example for 12 minutes 1, a tear-resistant and solvent-stable fleece is obtained.

Example 4 A mixed fiber fleece (wool, polyamide fibers, cotton) is impregnated with a 55% solution of a polyester in the immersion process 1 mole of MaleinsGure, 2 moles of phthalic acid and 3 moles of propylene glycol in a mixture of 70 parts of styrene, 15 parts of acrylic acid n-butyl ester and 15 parts of acrylonitrile and contains 0.1% paraffin, 0> 3% benzoin methyl ether and 0.7% diisopropylxanthogen disulphide as additives. It is exposed as in Example 1 for 12 minutes. The fleece contains 100 percent by weight, based on the raw fleece, binding agent, has a pleasant grip and remains with Shaking in trichlorethylene after 30 min. Obtained more than 90 area percent.

Example 5 As in Example 4, a mixed fiber fleece with 200 Percentage by weight, based on the raw fleece, impregnated binder. As a binder an above solution of a polyester from 7,7-hexachloro-2,5-endomethylene-1,2,5,6-tetrahydrophthalic acid is used and 1,4-butanediol-styrene. 0.1% paraffin and 0.6% benzoin isopropyl ether are added to the binder and 0.3% tetramethylthiuram disulride added. It will take 15 minutes with the example 1 specified lamps exposed. The fleece is 90% solvent-resistant and has reduced Flammability.

Example 6 With the solution of the unsaturated polyester in styrene according to Example 1, which does not contain paraffin and instead of 0.5% benzoin methyl ether 3.5 % BenzoinisopropylSther contains, a nylon fleece, as indicated in Example 1, impregnated and the excess squeezed off. The impregnated fiber fleece turns 15 Exposed for minutes with the lamps mentioned in Example 1. That solidified Fleece has the good properties mentioned in Example 1.

Claims (1)

Claim Method for producing nonwovens, characterized in that, that fiber webs with 10 to 300 percent by weight, based on the fiber web, a mixture of unsaturated polyester, at least one polymerizable olefinically unsaturated monomeric compound with a boiling point of over 50 ° C and at least one photoinitiator in amounts of 0.01 to 4 percent by weight on the polyester / monomer mixture, impregnated and then photochemically hardens.