KR20050024456A - Liquid duroplastics - Google Patents

Abstract

The present invention relates to a strengthened liquid durohplastic material prepared by the addition of pyrolytically prepared silica to the duroh plastic material, surface modified with methacryl group containing silane.

Description

Liquid duroplastics

Comparative Example 1:

100 parts by weight of an unsaturated styrene-containing isophthalic acid polyester resin and 1 part by weight of a 33% methyl ethyl ketone peroxide solution in dimethyl phthalate are mixed using a dissolvers. Viscosity is measured at 23 ° C using a flow meter. (Viscosity data measured in this example and the following examples are summarized in Table 1). The liquid is then poured into a right angle steel mold lined with separation foil and heated at 80 ° C. under a closed pressure of 100 bar for 15 minutes. During this time, the composition is fully cured and shaped as a transparent sheet.

Comparative Example 2:

100 parts by weight of the resin from Comparative Example 1 were mixed with 15 parts by weight of silica using a dissolver, wherein the silica was coated with trimethylsilyl group, prepared by flame hydrolysis, and had a specific surface area of 173 m ² and measured by carbon analysis. The content is 3.4% by weight and its structure has been modified by mechanical post treatment. Viscosity is measured at 23 ° C. with short degassing in a low pressure cabinet. The paste composition thus obtained has significant flow restrictions, but is diffusible. 1% by weight of 33% MEK peroxide solution is added thereto and heated in a right angle mold at 80 ° C. over 15 minutes. During this time, the formulation is fully cured and removed from the mold as a transparent sheet.

Example 1 (Prior Art)

15 parts by weight of silica containing methacryl group, prepared by flame hydrolysis, specific surface area of 160 m ² / g, average particle size of 12 nm, and carbon content of 5% using an unsaturated styrene-containing isophthalic acid polyester resin 100 Mix with parts by weight. Mixed air is removed by short degassing in a low pressure cabinet. Viscosity is measured at 23 ° C. using a conical / plate flow meter.

The composition has a flow limit but is very easily diffuseable. 1% by weight of 33% MEK peroxide solution is added thereto and heated in a right angle mold at 80 ° C. over 15 minutes. During this time, the composition is fully cured and is removed from the mold as a transparent sheet.

Comparative Example 3 (Prior Art)

1% by weight of 33% MEK peroxide solution is added to 100 parts by weight of unsaturated styrene-containing vinyl bromide ester resin as in Example 1, the mixture is molded to form a sheet, and then cured.

Comparative Example 4 (Prior Art)

100 parts by weight of an unsaturated styrene-containing vinyl bromide ester resin was mixed with 15 parts by weight of silica as in Example 1, wherein the silica was coated with trimethylsilyl group, prepared by flame hydrolysis, and had a specific surface area of 173 m ² and a structure thereof. It is changed by mechanical post-treatment. The composition flows easily.

Example 2 (according to the invention)

15 parts by weight of unsaturated styrene containing methacryl groups, prepared by flame hydrolysis, specific surface area of 160 m ² / g, average particle size of 12 nm, carbon content of 5% and its structure modified by mechanical post-treatment It mixes with 100 weight part of containing vinyl bromide resin. There is no noticeable flow limit and the composition can be poured very easily. It is mixed with 1% by weight of 33% MEK peroxide solution, degassed, molded to form a sheet and cured as in Example 1.

Comparative Example 5 (Prior Art)

Monomer component (a) 20-95 consisting of 60-100 weight part of (meth) acryl compounds (a1), 0-40 weight part of polyfunctional (meth) acrylates (a2), and 0-10 weight part of graft crosslinking agents (a3). weight%,

5 to 80% by weight of polymer (b) soluble in component (a) and

100 parts by weight of a solution of PMMA resin in monomeric methyl methacrylate, having a composition of already 0.1 to 15% by weight free radical generating agent (c) with a low flow limit, is mixed with 3% by weight of curing agent and poured to form a thin sheet And cured at room temperature. After 15 hours, the sheet is fully cured. The surface has residual tack.

Comparative Example 6 (according to the invention)

15 parts by weight of silica containing trimethylsilyl group and prepared by trimethylsilyl flame hydrolysis, specific surface area of 173 m ² / g, average particle size of 12 nm, and carbon content of 3.4% 100 parts by weight of PMMA resin from Comparative Example 5 Mix with The formulation has a significantly increased flow limit compared to Comparative Example 5. It is mixed with 3% by weight of curing agent, poured to form a sheet, and cured at room temperature. The surface has some residual tack.

Example 3 According to the Invention

100 parts by weight of the PMMA resin from Comparative Example 5 were intimately mixed with 15 parts by weight of silica by a lab dissolver, wherein the silica contained methacryl groups and was prepared by flame hydrolysis and had a specific surface area of 160 m ² / g. The flow limit is only slightly increased compared to the unfilled resin (Comparative Example 5). The mixture is then mixed with 3 parts by weight of the curing agent, poured to form a thin sheet and cured at room temperature. After 16 hours, the sheet is fully cured. The surface is non-tacky.

Summary of test results

Properties of Uncured Formulations Viscosity at 5 / s (Pas) Thixotropic Index 2.5 / 5 Flow Limit (Pas) Comparative Example 1 1.34 One 0.2 Comparative Example 2 101.7 1.68 218 Example 1 12.9 1.42 7.6 Comparative Example 3 0.573 One 0.002 Comparative Example 4 95.7 1.77 258 Example 2 2.62 1.13 0.1 Comparative Example 5 8.24 One 40 Comparative Example 6 69 1.65 261 Example 3 23 1.26 65

Evaluation of Table 1:

At selected high doses, silica containing methacryl groups and prepared by flame hydrolysis achieves a relatively small viscosity increase as well as a low flow limit of the plastic resin composition. This property is very advantageous for further processing.

Characteristics of Cured Formulations Shore D (10s / 60s) Indentation hardness Tensile Strength (Mpa) Tensile Modulus (Mpa) Bending modulus Comparative Example 1 78/76 87 47 2367 13853 PE Comparative Example 2 84/83 106 48 3507 18893 R8200 Example 1 84/83 118 55 4103 23764 R7200 Comparative Example 3 86/85 73 70 4218 23764 VE Comparative Example 4 85/84 119 50 4960 25213 R8200 Example 2 85/84 121 43 6051 23540 R7200 Comparative Example 5 82/80 101 n.m. n.m. n.m. MMA Comparative Example 6 83/81 110 n.m. n.m. n.m. R8200 Example 3 85/83 129 n.m. n.m. n.m. R7200

Evaluation of Table 2

As expected, both silicas cause an increase in hardness and modulus in the crosslinked resin formulation. Despite the relatively low BET surface area, silica modified with methacryl groups is distinguished by a substantially more pronounced action, which leads to a noticeable brittleness of the resin in Example 2. One of ordinary skill in the art will recognize the savings potential here, and will reduce capacity and use more flexible base resins.

The present invention relates to a process for strengthening liquid duroplastics and to the resulting duroplastics.

Duroplastics material means all plastic materials made from curable resins. According to DIN 7724, below the decomposition temperature they are crosslinked closed reticulated high polymer materials which are strongly-elastic at low temperatures and elastically behave with very limited deformation at temperatures between 50 ° C and decomposition. Shear modulus does not drop below 10 ² kp / cm ² at a given temperature.

Duroplastic materials are generally amorphous. Due to the crosslinking of the duroplastic materials, their molecules are not able to perform any macro-brown movement. On the other hand, micro-Brownian movement of polymer molecules is possible at glass transition temperatures in excess of 50 ° C.

The term duroplastic material has the same meaning as the term duromer, which is often preferred because it is a designation for two different classes of plastic materials because the form is very closely related to elastomers and plastomers (thermoplastics). Do.

Duroplastic materials are widely used as molding compositions, molding resins, resin adhesives and lacquer resins. Duroplastic materials include, in particular, diallyl phthalate resin (DAP), epoxy-maleamine-formaldehyde resin (MF), melamine-phenol-formaldehyde resin (MP), phenol-formaldehyde resin (PF) and unsaturated polyester resins ( UP) includes a commercially important group of materials (in parentheses, abbreviations according to DIN 7728, P1, January 1, 1988).

It is known to use powdered silica as a filler for polymers.

In general, finely distributed fillers in the form of hard phases surrounded by softer polymers improve many of the commercially available mechanical properties. This includes hardness, tensile strength, stress values and other measurable properties.

In principle, the thermoplastic polymer and the crosslinkable polymer should be distinguished. Silica can be used as filler in both classes of materials. However, the amount and effect of addition due to the polymer can be very different.

It is also known to use silica as a thickener in liquid duroplastic materials. However, this is not the subject of the present invention, but rather the thickening action of silica should be as small as possible.

The present invention describes the use of silica modified with unsaturated organic groups in low molecular weight, generally liquid, reactive polymers. This will achieve an advantageous combination of rheological and mechanical properties, i.e. an advantageous combination of low viscosity and low flow restriction in the uncrosslinked state on the one hand, and an advantageous combination of high hardness and high modulus in the crosslinked state on the other hand. It turns out that you can.

It is known to treat the fillers used in the polymers with vinylsilane or methacryl silanes in order to obtain advantageous properties in the crosslinked product. It is in accordance with the prior art to carry out this treatment while mixing the filler with the polymer.

A disadvantage of this process is that the chemical reaction sequence required for the desired bonding of silane to solids occurs under an uncontrollable environment and some reproducibility thereof is required. Moreover, alcohols are formed as unavoidable waste products, which are generally undesirable as constituents of polymeric materials and have to be removed in complex operations.

The silanes themselves and the degradation products formed therefrom present a risk associated with combustibility and toxicity and often require additional safety measures and investments. Therefore, it is preferable to use fillers which already contain the desired reactive group and which do not release undesirable substances into the polymer or the environment.

The present invention provides a method for strengthening a liquid durroplastic material, the method of the present invention is characterized in that a mixture of silica and uncrosslinked resin prepared by pyrolysis, surface-modified with methacryl group-containing silane, is prepared. do.

The present invention also provides a liquid durohplastic material characterized by containing silica produced by pyrolysis, surface modified with methacryl group containing silane. In certain embodiments of the invention, silica produced by pyrolysis can be structurally modified.

According to the invention, particularly effective fillers are silicas which contain methacryl groups and are prepared by flame hydrolysis and whose structure has been altered by mechanical workup.

Silica prepared by the pyrolysis method which can be used according to the present invention has a BET specific surface area of 20 to 380 m ² / g, particle size of 6 to 110 nm, tapping density of 50 to 600 g / l, pH value of 3 to 10 and carbon It is characterized by a content of 0.1 to 15% and a DBP number of less than 200%.

It can be prepared by first mixing the silica closely with water or dilute acid in a suitable mixing device and then mixing it with the surface modifier or by applying a mixture of various modifiers by spraying. The components are further mixed for 15 to 30 minutes and then heat treated over 1 to 6 hours at a temperature of 100 to 400 ° C.

In a preferred embodiment of the present invention, silica produced by pyrolysis can be used as silica.

Fumed silica is produced by flame hydrolysis of volatile silicon compounds such as SiCl ₄ , methyltrichlorosilane and the like. These are known from Ullmann's Enzyklopadie der technischen Chemie 4th edition, volume 21, page 464 (1982).

In a preferred embodiment of the invention, exothermic silicas having a BET surface area of approximately 200 m ² / g can be used.

As surface modifiers, monomeric materials such as methacryloxypropyltrialkoxysilanes in which alkoxy may be methoxy, ethoxy and / or propoxy may be used.

A practical feature of the invention mentioned is the combination of fillers by photopolymerization with reactive monomers and lacquer oligomers.

Surprisingly, in certain liquid resin systems, even in the absence of light rays, silicas containing methacryl groups and prepared by flame hydrolysis and whose structure has been altered by mechanical post-treatment are known as hard polymers distinguished by their advantageous properties. It was found to produce disproportionately.

Examples of such resin systems are as follows:

Unsaturated polyester resins of various compositions:

A. ethylenically unsaturated polyester,

B. ethylenically unsaturated monomers copolymerized with component (A),

C. 5-300% by weight fibrous reinforcement (based on component (A + B)),

D. any powder filler,

E. 0.5 to 5% by weight of any thickener (based on component (A + B)),

F. 0.5-5% by weight of organic peroxides (based on component (A + B)),

G. aromatic amines, metal salts of organic acids such as cobalt compounds and

H. Any further conventional additives.

A. As unsaturated polyesters, conventional polycondensation products of polyhydric, in particular divalent carboxylic acids and their esterifiable derivatives, especially anhydrides, are suitable, which are esterified in the manner of polyhydric, in particular bound to dihydric alcohols and are monohydric alcohol radicals And / or optionally further contains a hydroxycarboxylic acid radical, wherein at least part of the radical should have an ethylenically unsaturated copolymerizable group.

Multivalent, especially divalent, optionally unsaturated alcohols include conventional alkanediols and oxalkanediols having bicyclic or cyclic groups such as ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1 , 3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, 2,2-dimethylene-1,3-propanediol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, 1 Preference is given to, 2-cyclohexanediol, 2,2-bis- (hydroxy-cyclohexyl) -propane, trimethylolpropane monoallyl ether or 1,4-butanediol.

In addition, small amounts of mono, tri or higher alcohols such as ethylenehexanol, fatty alcohols, benzyl alcohol, 1,2-di- (allyloxy) -propanol- (3), glycerol, pentaerythritol Or trimethylolpropane may be used simultaneously. Polyhydric, especially dihydric alcohols generally react in stoichiometric amounts with polybasic, especially dibasic carboxylic acids or their condensable derivatives.

Suitable carboxylic acids and their derivatives are dibasic olefinically unsaturated, preferably β-olefinically unsaturated carboxylic acids such as maleic acid, fumaric acid, chloromaleic acid, itaconic acid, methyleneglutaric acid, mesaconic acid and derivatives thereof, Or preferably these anhydrides. In addition, aromatic carboxylic acids with modifications condensed with polyesters, as well as other dibasic unsaturated and / or saturated carboxylic acids, such as succinic acid, glutaric acid, methylglutaric acid, adipic acid, sebacic acid, pimelic acid , Phthalic anhydride, o-phthalic acid, isophthalic acid, terephthalic acid, dihydrophthalic acid, tetrahydrophthalic acid, tetrachlorophthalic acid, 3,6-endomethylene · 1,2,3,6-tetrahydrophthalic acid, endomethylenetetrachlorophthalic acid or Hexachloroendomethylenetetrahydrophthalic acid, but also monobasic, tribasic and higher basic carboxylic acids such as ethylhexanoic acid, fatty acids, methacrylic acid, acrylic acid, propionic acid 1,2,4,5-benzene-tetracarboxylic acid It is also possible. Maleic acid or anhydrides thereof and fumaric acid are preferably used.

Unsaturated polyesters prepared using dicyclopentadiene can also be advantageously used.

It is also possible to use mixtures of unsaturated polyesters, including those which have only limited solubility in monomers (B) and are easily crystallized. Such unsaturated polyesters which are easily crystallized may be composed of, for example, fumaric acid, adipic acid, terephthalic acid, ethylene glycol, 1,4-butanediol, 1,6-hexanediol and neopentyl glycol.

Unsaturated polyesters have an acid value of 5 to 200, preferably 20 to 85, and an average molecular weight of about 800 to 6000, preferably about 1000 to 4000.

Amorphous and optionally crystallizable unsaturated polyesters are generally prepared from their starting components by melt condensation under azeotropic conditions according to a continuous or discontinuous process.

B. Suitable copolymerizable ethylenically unsaturated monomer compounds are allyl and preferably vinyl compounds commonly used in the preparation of unsaturated polyester molding compositions, for example vinyl aromatic compounds such as styrene, methylenestyrene, p-chlorostyrene Or vinyltoluene), esters of acrylic acid and methacrylic acid with alcohols having 1 to 18 carbon atoms (e.g., methacrylic acid methyl ester, acrylic acid butyl ester, ethylhexyl acrylate, hydroxypropyl acrylate, dihydrodicyclopentadienyl Acrylates, butanediol diacrylates and (meth) acrylic acid amides), allyl esters such as diallyl phthalate and vinyl esters such as ethylhexanoic acid vinyl ester, vinyl acetate, vinyl propionate, vinyl pivalate and the like. . Also suitable are mixtures of the olefinically unsaturated monomers mentioned. Preferably, as component (B), styrene, vinyltoluene and diallyl phthalate are suitable. The monomer (B) is generally contained in the polyester molding composition in an amount of 10 to 80% by weight, preferably 20 to 70% by weight, based on the total weight of components (A) and (B).

C. Reinforcing fibers include inorganic or organic fibers in the form of rovings or flat structures optionally woven therefrom, such as mats (eg glass, carbon fibers, asbestos, cellulose) and synthetic organic fibers (eg polycarboxylic acid esters). , Polycarbonates and polyamides) are suitable. Reinforcing fibers are used in amounts of 5 to 300% by weight, preferably 10 to 150% by weight, based on component (A + B).

D. Suitable fillers are, for example, conventional finely divided or granular inorganic fillers such as chalk, kaolin, quartz powder, dolomite, barite, metal powder, aluminum hydrate, cement, talc, diatomaceous earth, wood dust, Great rice and pigments. These are used in amounts of 0 to 200% by weight in the SMC molding composition and in amounts of 100 to 400% by weight in the BMC molding composition, based on component (A + B).

E. As thickeners, mention may be made, for example, of alkaline earth oxides or hydroxides such as calcium oxide, calcium hydroxide, magnesium hydroxide and preferably magnesium oxide as well as mixtures of oxides or hydroxides thereof. They can also be partially replaced by zinc oxide. In some cases polyisocyanates or metal alcoholates are suitable. The thickener is added to the molding composition in an amount of 0.5 to 5% by weight, based on component (A + B).

F. As the polymerization initiator, 0.05 to 5% by weight, preferably 0.1 to 3% by weight, of ordinary organic peroxides that generate free radicals at elevated temperatures, based on the total weight of components (A) and (B). Use in quantity. Suitable initiators are, for example, benzoyl peroxide, tert-butyl peroctoate, tert-butyl perbenzoate, dicumyl peroxide, di-tert-dibutyl peroxide and perketal, for example Trimethylcyclohexamonperketal, and percarbonate.

G. Conventional additional additives include, for example, inhibitors, for example hydroquinone, 2,6-dimethylhydroquinone, tert-butylbenzocatechin, p-benzoquinone, chloranyl, 2,6-dimethyl Quinones, nitrobenzenes such as m-dinitrobenzene, thiodiphenylamine or salts of N-nitroso-N-cyclohexylhydroxylamine, and mixtures thereof. The inhibitor is contained in the molding composition generally in an amount of 0.005 to 0.2% by weight, preferably 0.01 to 0.1% by weight, based on component (A + B).

As lubricants, for example, zinc stearate, magnesium stearate and calcium stearate and polyalkylene ether waxes are contemplated.

Such polyester resins are known, for example, from EP 0 120 272 A1.

VE resins, also known as vinyl ester resins and phenacrylate resins (abbreviated PHA), are reaction resins based on phenyl (ene) derivatives, for example, aromatics of phenols in which molecules are esterified with (meth) acrylic acid. Glycidyl ether or epoxidized novolac.

So-called "vinyl ester" classes of resins have been recognized for many years as useful in various resin applications, especially those requiring good chemical resistance. Such resins are chemical reaction products of epoxy resins and ethylenically unsaturated products of epoxy resins. Commercial vinyl commercial resins currently commercially available include EPOCRYL resins (commercially available from Shell Chemical Company), DERKANE 411 (Dow Chemicals Company). Commercially available from Saga] and CO-REZYN VE-8300 (available from Itnerplastic Company).

In the use of vinyl ester resins in the production of molded articles, in particular glass fiber reinforced plastic (FRP) structures, the viscosity of the resin composition is fluid enough to allow the composition to permit easy applicability of the filler and good wettability and reinforcement. It should be adjusted so that it is not fluid to the extent that it is ejected from it and causes resin depletion in the molding. Furthermore, in many applications, for example, when molded articles such as pipes, tanks, dust collectors or conduits are produced using vinyl ester resins, good body and support characteristics are not critical to the process, but especially molding and Very important during the curing step. In this field, the resin is usually dissolved in a vinyl monomer, for example styrene, and then molded and cured to produce a molded article. During the molding and curing step, the resin surface of the molded article may be of an uneven thickness if the body and supporting features of the composition cause an outflow or flow of the composition, for example when the resin composition is applied to a vertical surface for lining. And reduced mechanical strength.

It has already been proposed to add certain thixotropic agents to improve the viscosity, body and support characteristics of vinyl ester resins. Fumed silica has been reported to be a "very effective" thixotropic additive in certain vinyl ester resin compositions. See "Unsaturated Polyester Technology" edited by Paul F. Gruins; Gordon and Breach Science Publishers.

Compositions of the present invention may include comonomers to promote handling and curing and to provide the desired mechanical properties. Suitable miscible comonomers include reactive ethylenically unsaturated comonomers such as styrene, chlorostyrene, vinyltoluene, methylstyrene, diallyl phthalate, triallyl cyanurate, acrylate esters, methacrylate esters and divinyl -Benzene is included. Styrene is the preferred miscibility adjuvant. The composition may also include non-reactive diluents, such as acetone, if properties that can only be obtained by pure resins are desired.

The vinyl ester resin used in the present invention may be any resin known in the art and may be prepared by addition reaction of an epoxy resin with an ethylenically unsaturated monocarboxylic acid. Processes for producing suitable vinyl ester resins are described in U.S. Pat. It is described in.

In general, the reaction for producing the vinyl ester resin used in the present invention is a direct reaction. It may be catalyzed by a suitable catalyst, for example tertiary amine, phosphine, alkali or onium salts. The general scheme can be written as:

In the above scheme, R is, for example, alkylene, cycloalkylene, arylene, arylalkylene, oxyarylene, oxyarylalkylene or cycloalkylene ester.

Suitable acids are acrylic acid, methacrylic acid, crotonic acid and cinnamic acid. Suitable epoxy resins are as follows:

Substantial numbers of different vinyl esters combining different features can be prepared by combining different epoxy resins with various unsaturated acids. Of course, various products can be further extended depending on the choice of unsaturated monomers that can be blended and copolymerized with the vinyl ester resin. Preferred vinyl ester resins for achieving maximum use and for use in the present invention are bisphenol-A (BPA) -epoxy based vinyl ester resins. These resins can be used in the compositions of the present invention with or without co-reactive monomers such as styrene.

In addition to vinyl ester resins, thixotropic additives and, optionally, reactive or non-reactive diluents, the resin compositions of the present invention may also include catalysts, inhibitors, fillers, pigments and / or other known conventional additives.

The compositions of the present invention can be polymerized and crosslinked using free radical generating initiators known in the art. The polymerization reaction of the resin is substantially by addition reaction, and usually no by-products are formed. Suitable initiators include peroxides, preferably organic peroxides such as benzoyl peroxide or methyl ethyl ketone peroxide, and other free radical sources. For example, a photoinitiator that generates free radicals can be used to initiate the polymerization of the compositions of the present invention. Initiators can be used with conventional accelerators or accelerators, such as tertiary amines such as dimethyl or diethyl aniline, and metallic soaps such as cobalt or manganese octoate or naphthenate.

Various molding methods can be used to mold the resin composition. Suitable methods include hand layup methods, cold press methods, bag methods, matched die methods, filament winding methods and continuous molding methods.

The acrylic resin can be a cooling or heat curable synthetic resin, which is obtained by homopolymerization of (meth) acrylic acid esters (so-called pure A.) or by copolymerization with, for example, styrene or vinyl esters. Heat curable acrylic resins further contain functional groups capable of conducting crosslinking reactions (hydroxy, hydroxymethyl, carboxy groups), which are self-crosslinked or (eg, aminoplastic or epoxy resins). After addition) can be crosslinked by external means. The solubility and mechanical properties of the acrylic resin can vary widely depending on the choice of monomer. Cured acrylic resins are generally transparent products that are resistant to UV light and free from discoloration.

The cooling cured coating resin has the following composition, for example,

(A) 50 to 100% by weight of (meth) acrylate,

0-5% by weight of methyl (meth) acrylate,

0-5% by weight ethyl (meth) acrylate,

0 to 97% by weight of C ₃ -C ₆ (meth) acrylate,

≥C ₇ (meth) acrylate 0-50% by weight,

Polyvalent (methacrylate) 3 to 10% by weight,

Comonomer 0-50% by weight,

0-30% by weight of a vinyl aromatic compound,

0 to 30% by weight of vinyl esters (where the sum of the components of component (A) is 100% by weight),

(B) 0 to 2 parts by weight of the (pre) polymer [soluble per component (A) [per 1 part by weight of component (A)] (wherein the amount of methyl (meth) acrylate or ethyl (meth) acrylate is a component Exceeding 5% by weight based on (B)),

(C) 2 to 5 parts by weight of one or more paraffins and / or waxes [per 100 parts by weight of component (A + B)],

(D) a redox system that must be separated for at least one component of the redox system until the polymerization of the polymerizable component of the redox system, wherein the redox system is in an amount sufficient for cold curing of component (A) Accelerators and peroxide catalysts or initiators),

(E) It contains a usual additive.

The mixed resin may be a mixture of polyester resin and vinyl ester and / or acrylic resin, in order to achieve a combination of properties which are particularly advantageous from a commercial point of view.

The resin is carefully mixed with silica and a curing agent and optionally an accelerator are added. Depending on the curing agent, curing occurs at a temperature that can be distinctly below room temperature, in the room temperature region or in a temperature range clearly above room temperature. The uppermost temperature limit is generally determined by the physicochemical data of the resin, for example the vapor pressure of the monomers.

Duroplastic materials according to the invention containing structurally modified silica containing acrylic groups may be in liquid, paste or solid form.

They are additional powder or fibrous filler materials, for example quartz powders, glass fibers, pigments, flame retardants, metal oxides, metal powders, graphite, carbon black or liquid additives in the form of solvents, plasticizers, non-reactive extender resins (e.g. hydrocarbons). Resins), flexibility imparting resins and phenolic resins, waxes, polymerization aids and adhesion promoters.

Further additives may be thickeners, blowing agents, mold release agents and stabilizers for increasing the useful life.

Silicas used according to the invention, which contain methacryl groups and are prepared by flame hydrolysis and whose structure has been altered by mechanical post-treatment, have many technical advantages in the resins according to the invention and formulations prepared therefrom. Cause.

In contrast to known finely divided silica, thixotropic action is very slow. This has many advantages in the application and loss behavior of coatings and adhesive formulations.

Acrylic functional groups bound tightly to the solid surface react during the polymerization of the reactive resin to form crosslinking sites, which give the final product a high degree of hardness, strength and elasticity. In addition, the rate of crosslinking reaction is increased so that the coating can be dust dried more quickly and the laminate can be removed from the mold faster.

Similarly, the treatment of the molding composition is improved, especially in the case of highly filled systems, and the reactivity of the silica according to the invention achieves uniform overall curing of the molding composition in a short time.

A particular advantage of using silica according to the invention containing methacryl groups and prepared by flame hydrolysis is that free alcohol is not formed at the time of manufacture, which is unavoidable when preparing liquid silanes according to the prior art.

Alcohols released by in situ silanization by hydrolysis reactions can cause various drawbacks, such as facilitating or delaying the crosslinking process, during further processing of the resin formulation. In addition, the silanization reaction requires not only measurable time and / or use of catalysts and / or heat, but also means of removing the optionally formed alcohol and excess silane.

The use of silicas according to the invention in liquid or paste resins containing methacryl groups and prepared by flame hydrolysis is not preceded by the effect, but in the precipitation behavior of other fillers, mainly those with relatively coarse particle sizes. It can have an advantageous effect.

Claims (3)

Liquid duroplastics, characterized in that they contain silica prepared by pyrolysis, surface-modified with methacryl group-containing silanes. The liquid duroroplastic material according to claim 1, characterized in that the silica produced by pyrolysis is structurally modified. A method of strengthening a duroh plastic material, characterized in that a mixture of a non-crosslinked resin with silica produced by methacryl group containing silane is prepared.