EP1709094A2

EP1709094A2 - Thermally polymerisable mixtures of multifunctional macromonomers, polymerisation initiators

Info

Publication number: EP1709094A2
Application number: EP05700913A
Authority: EP
Inventors: Kathrin Michl; Matthias Gerst; Yvonne Heischkel
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2004-01-21
Filing date: 2005-01-14
Publication date: 2006-10-11
Also published as: JP2007518858A; DE102004003262A1; WO2005070982A3; JP4348370B2; US20070161765A1; WO2005070982A2

Abstract

The invention relates to thermally polymerisable mixtures consisting of multifunctional macromonomers containing at least one radically polymerisable group. The invention also relates to polymerisation initiators and the use of said mixtures as binding agents for substrates, especially as binding agents for glass fibres, rock wool, synthetic fibres and for core sand binding.

Description

Thermally polymerizable mixtures of multifunctional macromonomers and polymerization initiators and their use as binders for substrates

description

The invention relates to thermally polymerizable mixtures of multifunctional macromonomers and polymerization initiators and their use as binders for substrates.

The production of insulating materials from glass fibers is known from US Pat. No. 5,275,874, the glass fibers being bonded to one another with the aid of a binder based on methacrylate or maleate which can be polymerized by the action of UV radiation. In order to achieve the most uniform possible hardening of the binder, it is necessary to expose the glass fibers treated with the binder to UV radiation for a long time. However, this damages the binder that is on the surface of the mixture of glass fibers and binder to be irradiated.

US-A-6,221,973 discloses a formaldehyde-free, crosslinkable aqueous composition comprising a polyacid, a polyol and a phosphorus-containing reaction accelerator for use as binders for heat-resistant nonwovens, e.g. Glass fibers.

EP-A-0 990727 discloses binders for mineral fibers made of a low molecular weight polycarboxy polymer and a polyol, the pH of the binder being not greater than 3.5.

US Pat. No. 5,932,665 discloses polycarboxy polymer-based binders, with this system it being possible to harden at lower temperatures by adjusting the molecular weight and the copolymer composition than in comparable systems made from homopolyacrylic acids.

WO-A-97/31036 describes formaldehyde-free, aqueous binders composed of an ethylenically unsaturated acid anhydride or an ethylenically unsaturated dicarboxylic acid and an alkanolamine as a coating agent, impregnating agent and binder for nonwoven fabrics.

In the process known from DE-A-44 10 020 for polymerizing substances in fiber materials, such as, in particular, binders in mineral fiber material for insulation purposes, the fiber material treated with binder is subjected to irradiation with electron beams. Examples of suitable binders are compounds which contain at least two ethylenically unsaturated double bonds in the molecule, for example hexane-1,6-diol diacrylate, tripropylene glycol triacrylate, ethoxylated trimethylolpropane triacrylate or ethoxylated pentaerythritol tetraacrylate. DE-A-4421 254 discloses a process for polymerizing prepolymers in fiber materials for the production of mineral wool materials for insulation purposes, the fiber material being impregnated with prepolymers and the fiber material coated in this way having a certain thickness briefly being exposed to UV radiation with a subject to high intensity with the proviso that a complete polymerization of the prepolymers takes place and that a degradation of organic substances on the surface of the coated fiber material is avoided. As a prepolymer, multifunctional acrylic or methacrylic compounds are suitable, for example oligomers or polymers with polymerizable, unsaturated functional groups such as acrylate, methacrylate, vinyl, vinyl ether, allyl or maleate groups, which in the sense of chain extension and / or Cross-linking react. The binder can be a mixture of such oligomers and contain a photoinitiator.

In the case of processes in which the polymerization of binders, such as monomers or prepolymers, takes place in a fiber matrix with the aid of radiation curing, the fiber material coated with binder can only be cured to such a thickness as the radiation penetrates into the material. Since the radiation decreases sharply with increasing thickness of the layer, an uneven polymerization of the monomers or the prepolymers can be expected unless certain complex measures are taken.

From WO-A-91/10713 an aqueous coating composition is known which is used in particular for coating finish foils and continuous edges. It consists of two paint components I and II, the paint component I containing at least one water-dilutable melamine and / or urea resin, at least one hydroxyl-containing polyester and optionally pigments, conventional auxiliaries and additives, and diluents, and the paint component II contains an acidic curing catalyst. The melamine and / or urea resins contained in the compositions contain condensed formaldehyde, which can be eliminated to a small extent, for example, when the coating compositions are thermally stressed.

EP-A-0279 303 discloses radiation-curable acrylates which, by reacting (A), have one equivalent of a 2- to 6-valent oxyalkylated C ₂ - to C ₁₀ -

Alcohol with (B) 0.05 to 1 equivalent of a 2 to 4-valent C ₃ to C ₃₆ carboxylic acid or its anhydrides and (C) 0.1 to 1.5 equivalents of acrylic acid and / or methacrylic acid and subsequent ones Reaction of the excess carboxyl groups with the equivalent amount of an epoxy compound are available. The acrylics thus prepared are optionally mixed with reactive diluents such as 4-tert-butylcyclohexyl acrylate or hexanediol diacrylate and used as coating and coating agents. You can do this with the help of a dispersant dispersed in water and in Form of aqueous dispersions, for example, applied to nonwovens and cured by the action of electron beams or after the addition of photoinitiators by irradiation with UV rays, cf. also DE-A-28 53 921.

Radiation-curable reaction products from acrylates and epoxy compounds such as epoxidized olefins or glycidyl esters of saturated or unsaturated carboxylic acids are known from EP-A-0686 632. Radiation-curable urethane acrylates are also known, cf. the older, not prepublished DE application 10259 673.

The present invention has for its object to provide formaldehyde-free binders for fibrous and / or granular substrates such as glass fibers, rock wool, other synthetic and natural fibers and sand for the production of moldings such as mats or sheets in particular. The binders are said to give the moldings high mechanical strength and dimensional stability.

The object is achieved according to the invention with thermally polymerizable mixtures of multifunctional macromonomers which contain at least one radically polymerizable group and polymerization initiators. The macromonomers contain, for example, acrylate, methacrylate, maleate, vinyl ether, vinyl and / or allyl groups as radical-polymerizable groups.

Pre-polymers which are known, for example, from the literature references EP-A-0279303, EP-A-0686 621, DE-A-4421 254 and the older DE application 10259673 are suitable as multifunctional macromonomers. The multifunctional macromonomers contain at least one radical-polymerizable group, which is selected, for example, from acrylate, methacrylate, maleate, vinyl ether, vinyl and allyl groups. The double bond content of the macromonomers is, for example, 0.1 to 1.0 mol / 100 g, preferably 0.2 to 0.8 mol / 100 g of macromonomer (100%). Accordingly, the macromonomers have, for example, a functionality of 1.5 to 7.0, in particular 1.6 to 5.0, per molecule. If the macromonomers contain more than one functional group, these groups can be the same or different. The molecular weights M _{w of} the macromonomers are, for example, 300 to 30,000, preferably 500 to 20,000 g / mol.

Multifunctional macromonomers can be obtained, for example, by condensation of di- or polyfunctional polyols, which can contain 2-30 mol ethylene oxide and / or propylene oxide, with polycarboxylic acids and / or carboxylic anhydrides and / or difunctional alcohols (C ₂ -C ₁₈ ) and / or alkanolamines which contain at least two OH groups in the molecule, with ethylenically unsaturated carboxylic acids. Examples of ethylenically unsaturated C ₃ - to C ₅ -carboxylic acids are e.g. As acrylic acid, methacrylic acid, crotonic acid, maleic acid, ethyl acrylic acid and vinyl acetic acid, preferably acrylic acid and methacrylic acid. Preferred polycarboxylic acids are unsaturated C to C ₃₆ dicarboxylic acids, for example succinic acid, glutaric acid, sebacic acid, adipic acid, o-phthalic acid, their isomers and hydrogenation products, and esterifiable derivatives, or dialkyl esters of the acids or trimellitic acid mentioned. Preferred carboxylic anhydrides are maleic anhydride, phthalic anhydride, succinic anhydride and itaconic anhydride. Excess acid in the reaction product is removed, either by neutralization and washing out with water or by reaction with epoxides with catalysis (tertiary amines, ammonium salts) to give epoxy acrylates, which remain in the reaction mixture.

The reaction products can then be treated with a polyisocyanate, e.g. 2,4 toluenediisocyanate, optionally in the presence of a chain extender such as hydroxyethyl acrylate, to form macromonomers containing acrylate and polyurethane groups.

Ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexanedimethanol and polyglycols which contain ethylene oxide and / or propylene oxide units are preferred as diols. Examples of polyols are trimethylolpropane, glycerol or pentaerythritol. The diols and polyols can optionally be reacted with ethylene oxide or propylene oxide to give polyethers. Up to 30 moles of ethylene oxide and / or propylene oxide, usually 2 to 30, preferably 2 to 10 moles of ethylene oxide or propylene oxide are used per OH group of the diols or polyols. Polyesters containing OH groups also include polycaprolactone diols and triols.

In the esterification of hydroxyl-containing polyesters with acrylic acid and / or methacrylic acid, it is also possible to use these acids together with the starting materials for the preparation of the polyesters containing OH groups, e.g. To present dicarboxylic acids or their anhydrides and diols or polyols and to condense these starting materials together with acrylic acid and / or methacrylic acid in one step.

In the esterification of the compounds containing OH groups with acrylic acid and / or methacrylic acid, 0.1 to 1.5, in particular 0.5 to 1.4, and very particularly preferably 0.7 to 1.3 equivalents of acrylic acid and / or methacrylic acid are preferred , based on 1 hydroxyl group equivalent of the hydroxy compound.

The reaction of acrylic acid and / or methacrylic acid with the compounds containing hydroxyl groups takes place, for example, in the presence of an acidic esterification catalyst such as sulfuric acid or p-toluenesulfonic acid. The esterification can also be carried out in the presence of a hydrocarbon which is aze- otropic mixture forms. The water formed during the esterification is then expediently distilled off azeotropically from the reaction mixture. After the esterification has ended, the solvent can be distilled off from the reaction mixture, and the distillation is preferably carried out under reduced pressure in order to avoid thermal damage to the reaction product.

Preferred multifunctional macromonomers are e.g. obtainable by

a) 0.5-2.0 equivalents of a 2- to 6-valent oxyalkylated alcohol with b) 0 to 1 equivalents of a 2- to 4-valent C ₃ - to -C ₆ carboxylic acid and / or their anhydrides and c) 0.1 up to 1.5 equivalents of acrylic acid and / or methacrylic acid d) 0 to 1 equivalent of diol

reacted simultaneously with one another and the reaction product thus obtained is then reacted with an epoxy compound.

Suitable epoxy compounds have at least one, preferably at least two or three epoxy groups in the molecule, e.g. epoxidized olefins, gyicidyl esters of saturated or unsaturated carboxylic acids or glycidyl ethers of aliphatic or aromatic polyols. Such products are commercially available, e.g. B. Polyglydicyl compounds of the bisphenol A type and glycidyl ethers of polyfunctional alcohols such as butanediol, glycerol or pentaerythritol, such as Epikote®812 (epoxy value: approx. 0.67), Epikote 828 (epoxy value: approx. 0.53) and Epikote 162 (epoxy value: approx.0.61).

The epoxy compounds are generally added to the reaction product obtained in the first stage in amounts of 1 to 20% by weight, preferably 5 to 15% by weight, based on the reaction product in the first stage. Equimolar amounts of epoxy compounds are particularly preferably used, based on the amounts of acid equivalents still present in the reaction product of the first stage. In the reaction with epoxy compounds in the second stage of the reaction, excess or unreacted acid, in particular acrylic acid and / or methacrylic acid, but also, for example, dicarboxylic acid still present in a mixture as a starting material or monoesters of dicarboxylic acids formed with a free acid group are bound as epoxy esters , The reaction with epoxy compounds is preferably carried out at 90 to 130, preferably at 100 to 110 ° C. The reaction is carried out until the reaction mixture has an acid number below 10, in particular below 5 mg KOH / g. According to the prior art, the reaction of the epoxy compounds with the acid groups of the reaction products obtained in the first stage is preferably carried out in the presence of quaternary ammonium or phosphonium compounds, cf. EP-A-0686 621. They are described in Amounts of, for example, 0.01 to 5, in particular 0.1 to 2,% by weight, based on epoxy compounds.

Further multifunctional macromonomers can be prepared, for example, by reacting the multifunctional macromonomers described above with a polyisocyanate, for example 2,4-toluene diisocyanate, after the reaction with an epoxy compound, if appropriate in the presence of a chain extender such as hydroxyethyl acrylate, to form macromonomers containing acrylate and polyurethane groups implements.

The macromonomers containing multifunctional groups are in most cases prepared in the presence of inhibitors in order to prevent premature polymerization of the monomers. According to the invention, they are mixed with polymerization initiators which are heated e.g. decompose into radicals at temperatures above 40 ° C., preferably above 50 ° C., and thereby initiate the polymerization of ethylenically unsaturated compounds (so-called thermal polymerization initiators). The mixtures of multifunctional macromonomers and polymerization initiators according to the invention each contain, based on the solids, 0.05 to 15, preferably 0.5 to 10% by weight of at least one thermal polymerization initiator and 99.95 to 85, preferably 99.5 to 90% by weight of multifunctional macromonomers. Mixtures which contain 1.0 to 5.0% by weight of at least one polymerization initiator, which breaks down into free radicals when the mixtures are heated and thereby initiates the polymerization of the macromonomers, are particularly preferred.

Suitable polymerization initiators are, for example, peroxides, hydroperoxides, peroxydisulfates, percarbonates, peroxiesters, hydrogen peroxide and azo compounds. Examples of initiators, which can be water-soluble or water-insoluble, are hydrogen peroxide, dibenzoyl peroxide, dicyclohexyl peroxidicarbonate, dilauroyl peroxide, methyl ethyl ketone peroxide, di-tert-butyl peroxide, acetylacetone peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, tert-butyl peroxide,. Butyl perpivalate, tert-butyl perneohexanoate, tert-butyl per-2-ethylhexanoate, tert-butyl perbenzoate, lithium, sodium, potassium and ammonium peroxydisulfate, azodiisobutyronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2- (carbamoylazo) isobutyronitrile and 4,4-azobis (4-cyanovaleric acid).

The initiators can be used alone or in a mixture with one another, e.g. Mixtures of hydrogen peroxide and sodium peroxydisulfate. Water-soluble initiators are preferably used for the polymerization in an aqueous medium.

The known redox initiator systems can also be used as polymerization initiators. Such redox initiator systems contain at least one peroxide-containing term compound in combination with a redox coinitiator, for example reducing sulfur compounds, for example bisulfites, sulfites, thiosulfates, dithionites and tetrathionates of alkali metals and ammonium compounds. Combinations of peroxodisulfates with alkali metal or ammonium bisulfites can be used, for example ammonium peroxydisulfate and ammonium disulfite. The amount of the peroxide-containing compound to the redox coinitiator is, for example, 30: 1 to 0.05: 1.

In combination with the initiators or the redox initiator systems, additional transition metal catalysts can be used, e.g. Salts of iron, cobalt, nickel, copper, vanadium and manganese. Suitable salts are e.g. Iron-II-sulfate, cobalt-II-chloride, nickel-II-sulfate, copper-I-chloride. Based on monomers, the reducing transition metal salt is used in a concentration of 0.1 ppm to 1,000 ppm. So you can use combinations of hydrogen peroxide with iron-II salts, such as 0.5 to 30% hydrogen peroxide and 0.1 to 500 ppm Mohr's salt.

Redox coinitiators and / or transition metal catalysts can also be used in combination with the abovementioned initiators, for example in the polymerization in organic solvents, e.g. Benzoin, dimethylaniline, ascorbic acid as well as organically soluble complexes of heavy metals such as copper, cobalt, iron, manganese, nickel and chromium. The amounts of redox coinitiators or transition metal catalysts usually used here are usually about 0.1 to 1000 ppm, based on the amounts of monomers used.

The formaldehyde-free mixtures of multifunctional macromonomers and thermal polymerization initiators may optionally additionally contain at least one customary additive in the usual amounts, e.g. Emulsifiers, pigments, fillers, hardeners, anti-migration agents, plasticizers, biocides, dyes, anti-oxidants and waxes. The amounts of customary additives are, for example, 0.5 to 20% by weight.

The invention also relates to the use of thermally polymerizable mixtures of multifunctional macromonomers which contain at least one radical-polymerizable group and polymerization initiators as binders for substrates. Examples of fibrous substrates are glass fibers,

Rock wool, natural fibers such as cotton, fibers from wood and sisal, synthetic fibers such as fibers from polyester, polyacrylonitrile and nylon. The thermally polymerizable mixtures are also suitable for binding granular substrates, such as core sand. Depending on the shape, shaped bodies of various shapes are obtained, for example nonwovens, mats, plates or other shaped objects. The substrates are impregnated, for example, with the thermally polymerizable mixtures by spraying solutions or dispersions of the mixtures onto a substrate or immersing it in the substrate and the excess binder solution or dispersion of the immerses and drains off the excess binder solution or dispersion of the binder. The coated or impregnated substrates are solidified by heating to a temperature at which the mixtures according to the invention polymerize. This temperature depends on the particular decay characteristics of the polymerization initiator contained in the mixtures. The substrates coated or impregnated with the mixtures according to the invention are usually heated to temperatures in the range from 160 to 250 ° C., preferably 180 to 220 ° C. The heating time depends on various factors such as the thickness of the layer, the type of macromonomers and the decomposition temperature of the polymerization initiator. It is, for example, 2 to 90, preferably 2 to 30 minutes.

Based on the weight of the substrates, for example 2 to 35, preferably 5 to 25% by weight of the mixtures according to the invention are used as binders. Molded parts are obtained which have high mechanical strength and dimensional stability both in a moist climate and at elevated temperature.

Bound nonwovens are used, for example, as insulation material in the form of sheets or panels in the construction sector. The binders according to the invention are also suitable for the production of pot cleaners and pot scrapers based on bonded nonwovens.

The percentages in the examples mean percent by weight, unless the context indicates otherwise.

example 1

390 g of water and 180 g of a polymeric dispersing aid (30% aqueous solution of a copolymer comprising N-vinylpyrrolidone, vinyl acetate and vinyl acetate versatinate units with an expiration time of approximately 80 s measured with a Ford cup 5 in accordance with DIN 53211) were mixed in placed in a vessel provided with a stirrer and mixed with stirring with 450 g of a polyester acrylate which had been prepared according to Example 1 of EP-A-0279303 (polyester acrylate prepared by condensation of ethoxylated trimethylolpropane with an OH number of 630 mg KOH / g, Maleic anhydride and acrylic acid and subsequent reaction with the diglycidyl ether of bisphenol A).

1000 g of an aqueous dispersion with a viscosity of 250 mPas were obtained. The dispersion was mixed with 2%, based on solids content, of t-butyl perbenzoate. Example 2

In an apparatus equipped with a stirrer and a water separator, 1170 g of a 3: 1 molar ratio propoxylated and ethoxylated trimethylolpropane with an OH number of 480 mg KOH / g, 900 g acrylic acid and 9 g concentrated sulfuric acid, 560 g cyclohexane in The presence of 1.9 g of t-butyl p-cresol, 1.9 g of triphenyl phosphite, 1.9 g of hypophosphorous acid (50% in water), 5.6 g of 4-methoxyphenol and 0.2 g of phenothiazine were heated. 200 g of water were removed within 8 hours. The solvent was then distilled off in vacuo (20 mbar) at 100.degree. After the distillation, the acid number of the resin was approximately 1 mg KOH / g. It had a viscosity of 90 mPas according to DIN 53019. The polyether acrylate resin thus obtained was then mixed with 2% t-butyl perbenzoate.

Example 3

In an apparatus equipped with a stirrer and a water separator, 470 g of ethoxylated pentaerythritol with an OH number of 620 mg KOH / g, 440 g of acrylic acid and 2.5 g of concentrated sulfuric acid, 300 g of methylcyclohexane in the presence of 1 g of t-butyl p-cresol, 1 g triphenyl phosphite, 1 g hypophosphorous acid (50% in water), 3 g 4-methoxyphenol and 0.1 g phenothiazine heated. After a reaction time of 8 hours, 84 g of water were removed and 14 g of a 75% strength aqueous tetra (n-butyl) ammonium bromide solution were added. The solvent was then distilled off in vacuo (20 mbar) at 112 ° C. The acid number after distillation was approximately 80 mg KOH / g. The excess acrylic acid was reacted with 200 g of bisphenol A diglydidyl ether, epoxy content about 5.4 mol / kg, at a temperature of 105-110 ° C for 6 hours. The acid number of the polyether acrylate obtained was <5 mg KOH / g. The viscosity of the resin was 1.0 Pas according to DIN 53019. The resin was mixed with 2% t-butyl perbenzoate.

Example 4

In an apparatus equipped with a stirrer and a water separator, 1039.0 g of an approximately 15-fold ethoxylated trimethylolpropane with 304.0 g acrylic acid and 6.1 g sulfuric acid (96%) in 450.0 g methylcyclohexane were at an internal temperature esterified from 98 to 105 ° C. The stabilization was carried out with 1.2 g of t-butyl-p-cresol, 1.2 g of triphenyl phosphite, 1.2 g of hypophosphorous acid (50% in water), 4.0 g of 4-methoxyphenol and 0.037 g of phenothiazine. After a reaction time of 10 hours, 40.7 g of a 75% aqueous tetra (n-butyl) ammonium bromide solution were added and the solvent was distilled off at 112 ° C. in vacuo (20 mbar). The acid number after the distillation was 25 mg KOH / g. The OH number was 40 mg KOH / g. The excess acrylic acid was mixed with 106 g bisphenol A diglydidyl ether, epoxy content approx. 5.4 mol / kg, reacted for 2 hours at a temperature of 105-110 ° C. The acid number of the acrylate obtained was 2.0 mg KOH / g, the OH number 50 mg KOH / g.

467.5 g of the acrylate described above, 30 g of hydroxyethyl acrylate and 0.1 g of dibutyltin dilaurate were placed in an apparatus equipped with a stirrer and heated to 56 ° C. 58.2 g of 2,4-toluene diisocyanate were then added dropwise over a period of 20 minutes at an internal temperature of 55 to 65 ° C. The reaction was continued at an internal temperature of 65-70 ° C. for 7 hours until the isocyanate content had dropped to 0.5% by weight. Then 1.5 g of methanol were added and the reaction was continued at the same temperature for about 3 hours until the isocyanate content had fallen below 0.2% by weight. The urethane acrylate thus produced was then mixed with 2% t-butyl perbenzoate.

Application tests:

Formulation of the binder: 1% each (based on solids) of Silquest A-1100 (-aminopropyltriethoxysilane).

Raw fleece: glass fleece approx. 50 g / m ²

Solidification of glass fleece with the mixtures of multifunctional macromonomers and peroxides prepared according to Examples 1 to 4.

(a) with aqueous binders

Glass nonwovens 32 cm long and 28 cm wide were first lengthwise passed over a continuous PES sieve belt through a 20% aqueous binder liquor, each containing a mixture of multifunctional macromonomers and peroxide prepared according to Examples 1 to 4 , and then guided over a suction device. The belt speed was 0.6 m / min. The wet application was metered via an adjustable suction strength. In the case of a wet application of approx. 100%, a dry application of 20% + - 2% was obtained with a liquor concentration of the mixture of multifunctional macromonomers and peroxide of 20%.

b) binders dissolved in acetone

The glass fleece was placed in a 5% solution of the binder (a mixture of multifunctional macromonomers and peroxide prepared according to Examples 1 to 4) in acetone. The impregnated material was predried at 60 ° C. for 5 min after the solution had drained off. As in the case of aqueous impregnation, the amount of binder was set to 20% + - 2%. The impregnated nonwovens were cured for 3 minutes at 200 ° C. on a PES store as a carrier in a Mathis dryer (hot air was set to maximum).

Preparation of the test items:

5 test specimens for testing the tensile strength and 6 test specimens for testing the bending stiffness in the longitudinal direction were cut out of the impregnated nonwovens. The size of the fleeces for testing was

- Tear strength at 23 ° C without further treatment ("dry") 240 x 50mm tear strength after storage for 15 min in 80 ° C warm water ("wet") 240 x 50mm tear strength at 180 ° C ("hot") 200 x 50mm the bending stiffness 70x30mm.

Exams:

(a) tensile strengths

The averaged test values were given in N / 5cm, the clamping length was 200mm for testing the tensile strength "dry" and "wet", 140mm for testing the tensile strength. The pull-off speed was set to 25 mm / min When measured “hot”, the sample was heated to 180 ° C. in a sample chamber within one minute. After another minute at 180 ° C the tear strength was determined. The tensile strengths were weight-corrected to 60 g / m ² (calculation formula: F _max * 60 [g / m ² ] / “actual weight” [g / m ² ]). They are given in the tables.

b) bending stiffness

The test strips were each fastened in a clamping device and bent at a distance of 10 mm over a holder at an angle of 20 °. The height of the test strip was 30 mm. The measured force represented the bending stiffness. A total of 6 test specimens were measured from the front and rear and an average was determined. The results obtained are given in the tables.

Curing deviating from the procedure described above: 30 min at 200 ° C in a drying cabinet under a nitrogen atmosphere

Claims

claims

1. Thermally polymerizable mixtures of multifunctional macromonomers, which contain at least one radical-polymerizable group, and polymerization initiators.

2. Thermally polymerizable mixtures according to claim 1, characterized in that the macromonomers contain as radically polymerizable groups acrylate, methacrylate, maleate, vinyl ether, vinyl and / or allyl groups.

3. Thermally polymerizable mixtures according to claim 1 or 2, characterized in that the molecular weights M of the multifunctional macromonomers are 300 to 30,000.

4. Thermally polymerizable mixtures according to claims 1 to 3, characterized in that the molecular weights Mw of the multifunctional macromonomers are 500 to 20,000.

5. Thermally polymerizable mixtures according to claims 1 to 4, characterized in that the multifunctional macromonomers are obtainable by simultaneous reaction of a) 0.5-2.0 equivalents of a 2- to 6-valent oxyalkylated alcohol with b) 0 to 1 Equivalents of a 2 to 4-valent C ₃ to C ₆ carboxylic acid and / or their anhydrides and c) 0.1 to 1.5 equivalents of acrylic acid and / or methacrylic acid d) 0 to 1 equivalent of diol and subsequent reaction of the reaction product thus obtainable with at least one epoxy compound.

6. Thermally polymerizable mixtures according to claim 5, characterized in that the multifunctional macromonomers are obtainable by subsequent reaction of the reaction product reacted with an epoxy compound with a polyisocyanate, optionally in the presence of a chain extender, with the formation of macromonomers containing acrylate and polyurethane groups.

7. Thermally polymerizable mixtures according to claims 1 to 6, characterized in that they contain at least one initiator from the group of peroxides, hydroperoxides, peroxydisulfates, percarbonates, peroxiesters, hydrogen peroxide and azo compounds as polymerization initiators.

8. Thermally polymerizable mixtures according to claims 1 to 7, characterized in that they contain 0.05 to 15 wt .-%, based in each case on the solids, of a polymerization initiator.

9. Use of thermally polymerizable mixtures of multifunctional macromonomers which contain at least one free-radically polymerizable double bond, and polymerization initiators as binders for substrates.

10. Use according to claim 9, characterized in that the thermally polymerizable mixtures are used as binders for glass fibers, rock wool, natural fibers, synthetic fibers and for core sand binding.