Method of producing resin,especially for dental purposes

Inventor _

Patent holder: Bayer Aktiengesellschaft, Leverkusen (Federal Republic of Germany)

A method of producing resin, especially for dental purposes and

The present invention relates to a process for the production of a polyurethane resin containing vinyl groups, especially for dental purposes. These resins are used in impression materials, i.e. masses that undergo a hardening process from a plastic state to a hardened or elastic state. Impression materials are used in dentistry to recreate the shape corresponding to the mucosa and teeth. For this purpose, masses that are hardenable to a gum-type elastic consistency are preferably used.

The production of flexible rubber products can be carried out in various ways. In addition to the polymerization of unsaturated hydrocarbons with one or more double bonds to obtain rubber-type elastic products, for example, the hardening of thioplasts, which can take place by reaction of aqueous solutions of alkali metal polysulfides with aliphatic dihalides. De-rubber-like products are also obtained by polycondensation of silicates. Rubber-type elastic products can also be produced by polyaddition of polyester or polyether with a diisocyanate.

Thiokols before and after cross-linking have an unpleasant odor. Polyurethanes are not physiologically indifferent as they contain free isocyanate groups. Moreover, all of these masses exhibit relatively high polymerization shrinkage.

which one tries to compensate by introducing a high proportion of fillers.

Also, rubbery elastic masses similar to rubber are produced on the basis of ethylene imine. These products show relatively low polymerization shrinkage, but suffer from the following disadvantages: when water is added, there are strong changes in volume due to swelling processes, moreover, the products are not inert and physiologically because they are cross-linked via aziridine end groups, and some aziridines are known as carcinogens.

All impression materials used in ₁₅ dentistry has time constraints in terms of both the treatment period and the curing period. After the preparation of the reducible mixture, a working period of about 3 minutes is usually available. The next hardening period_M. usually takes about 5 rpinuts.

Surprisingly, it has been found that polyurethane resins containing vinyl groups can be hardened to flexible rubber-like masses during these practical periods, and that these masses used as impression materials do not have the above-mentioned disadvantages.

The subject of the invention is a method of producing a resin, especially for dental purposes, ₃₀ which is carried out in the molding process

113 841

113 841 into a cross-linked state, in which the reaction is:

a) diisocyanates,

b) dihydroxy compounds with a molecular weight of 300 to 10,000, preferably 1,000 to 8,000,

c) monohydroxy vinyl compounds, preferably acrylic and / or methacrylic acid derivatives containing hydroxyl groups.

Substances of group a) can be diisocyanates such as ethylene diisocyanate, hexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, 2,4- and 2,6-toluene diisocyanate and mixtures thereof, isophorone diisocyanate, phoronodiodiisocyanate, 1,5-naphthalene diisocyanate, 1,3-diisocyanate. cyclopentylene diisocyanate, m- and p-phenylenedisocyanate, 2,4,6-toluene triisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate, 1,3- and 1,4-xylylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyldiphenylene diisocyanate, 4,4^,- diphenylene diisocyanate, durene diisocyanate, 1-phenoxy-2,4'-phenylenediisocyanate, 1-tertiary-butyl-2,4-phenylenediisocyanate, methyl-bis-4.4^,-cyclohexyldiisocyanate 1-chloro-2,4-phenylenedisocyanate and 4,4'-diphenylether diisocyanate.

It is also possible to use higher molecular weight and optionally also higher functional polyisocyanates which are prepared from lower basic substances by polymerization into uretdiones or isocyanurate derivatives. Examples are uretdione with 2 moles of 2,4-toluene diisocyanate and polymerization products from 2,4-isocyanurate containing an isocyanurate ring. and 2,6-toluene diisocyanate or hexamethylene diisocyanate, a system with an average of 2 isocyanurate rings per molecule and formed from 5 moles of toluene diisocyanate, or the corresponding derivative with an average of 2 moles of toluene diisocyanate and 3 moles of hexamethylene diisocyanate.

It is also possible to prepare from di- or polyisocyanates by partial hydrolysis via the carbamic acid step and amines of higher urea- or biuret-coupled systems, such as e.g. a biuret-coupled compound, which is formally formed from 3 moles of hexamethylene diisocyanate with the addition of 1 mole of water and splitting of 1 moles of carbon dioxide.

Preferred substances containing isocyanate groups are also obtained during the reaction of di- or polyols with di- or polyfunctional isocyanates, if the molar ratio of the hydroxyl compound to the isocyanate is selected such that in the statistically formed reaction products, free NCO functions are still free and the molar weight does not exceed 2000-3000.

Particularly preferred isocyanate-containing compounds for use in the inventive resins are hexamethylene diisocyanate, toluene diisocyanate, isophorone diisocyanate and 4,4'-diphenylmethane diisocyanate.

Components b) used are compounds having two hydrogen atoms which are capable of reacting with isocyanates and having a molecular weight of 300 to 10,000, preferably 1,000 to 8,000.

As such compounds, in addition to compounds containing amino groups, thiol groups or carboxyl groups, preferably polyhydroxyl compounds, especially compounds having 2 to 8 hydroxyl groups, in particular compounds with a molecular weight of 300 to 10,000, preferably 1,000 to 8,000, e.g. generally two hydroxyl groups are polyesters, polyethers, polythioethers, polyacetals, polycarbonates and polyesteramides, as are known for the preparation of homogeneous and cellular polyurethanes.

Polyesters containing hydroxyl groups are, for example, reaction products of polyvalent, preferably divalent and optionally trivalent alcohols with polyvalent, preferably divalent carboxylic acids. Instead of free polycarboxylic acids, it is also possible to use the corresponding polycarboxylic acid anhydrides or polycarboxylic acid esters with lower alcohols or mixtures of these compounds for the preparation of the polyesters. The polycarboxylic acids may be aliphatic, cycloaliphatic, aromatic and / or heterocyclic in nature and may be optionally substituted, for example with halogen atoms, and / or may be unsaturated.

Examples of such compounds are succinic acid, adipic acid, cork acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid, phthalic acid anhydride, tetrahydrophthalic acid anhydride, hexahydrophthalic acid anhydride, tetrachlorophthalic acid anhydride, anhydride tetrachlorophthalic anhydride. glutaric acid anhydride, maleic acid, maleic acid anhydride, fumaric acid, dimeric and trimeric fatty acids such as oleic acid, optionally in admixture with monomeric fatty acids, terephthalic acid dimethyl ester and terephthalic acid bis glycol ester. The polyvalent alcohols used are e.g. ethylene glycol, propylene glycol-1,2 and -1,3, butylene glycol-1,4 and -2,3, hexanol-1,6, octadiol-1,8, neopentyl glycol, cyclohexanedimethanol (1,4-bis- hydroxymethylcyclohexane), 2-methyl-1,3-propadiol, glycerin, trimethylpropane, hexantriol-1,2,6, butantriol-1,2,4, trimethylethane, pentaerythritol, quinite, mannitol and sorbitol, methylglycoside, and also diethylene glycol, glycol triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, polypropylene glycols, dibutylene glycol and polybutylene glycols. The polyesters may contain some carboxyl end groups. Polyesters of lactones, for example ε-caprolactone, or of hydroxycarboxylic acids, for example, r-hydroxycaproic acid, can also be used.

The polyethers which are generally of two hydroxyl group and are also used in the present invention are compounds of a known type. They are obtained, for example, by the polymerization of epoxides such as ethylene oxide, propylene oxide,

113 841 of butylene, tetrahydrofuran, styrene oxide or epichlorohydrin with one another, for example in the presence of BF3, or by attaching these epoxides, optionally in admixture or sequentially, to starting components with reactive hydrogen atoms such as water, alcohols, ammonia or amines, for example ethylene glycol, 1,3 or -1,2 propylene glycol, 4,4'-two-hydroxy-diphenylpropane, aniline, ethanolamine. Preference is given to those polyethers which for the most part (up to 90% by weight, based on all OH groups present in the polyether) contain primary OH groups. Preference is also given to polyethers modified with vinyl polymers, e.g. by polymerization of styrene and acrylonitrile in the presence of polyethers (U.S. Patent Nos. 3,383,351, 3,304,273, 3,523,093, 3,110,695 and German Patent No. 1). 152 536) as well as polybutadienes containing OH groups.

Polythioethers are, in particular, the condensation products of thiodiglycol molecules with one another and / or with other glycols, dicarboxylic acids, formaldehyde, amino carboxylic acids or amino alcohols. Depending on the ingredients, mixed polythioethers, polythioether esters or polythioether esters are obtained as products.

Polyacetals are, for example, compounds obtained from glycols such as diethylene glycol, triethylene glycol, 4,4'-dioxyethoxydiphenyl dimethylmethane, hexadiol and formaldehyde. It is also possible to obtain polyacetals which can be used according to the invention by polymerization of cyclic acetals.

Known substances are used as hydroxyl-containing polycarbonates, which can be prepared, for example, by reacting diols such as 1,3-propadiol, 1,4-butanediol and / or 1,6-hexandiol, dimethylene glycol, triethylene glycol or tetraethylene glycol with diaryl carbonates. such as diphenyl carbonate or with phosgene.

Polyesteramides and polyamides include, for example, compounds obtained from polyvalent saturated and unsaturated carboxylic acids or their anhydrides and polyvalent saturated and unsaturated amino alcohols, avuamines, polyamines and mixtures thereof, with linear condensation products being preferred. /

It is also possible to use polyhydroxy compounds containing urethane or urea groups and optionally modified natural pliols such as castor oil, carbohydrates or starch. It is also possible to introduce alkylene oxide linkage products to phenol-formaldehyde resins or to urea-formaldehyde resins.

It is of course also possible to use mixtures of the abovementioned compounds having generally two hydrogen atoms capable of reacting with isocyanates and having a molecular weight of 300 to 10,000, for example mixtures of polyethers and polyesters.

As components c), polymerizable vinyl compounds with an isocyanate-reactable hydrogen are used. The hexalkylation products of acrylic and / or methacrylic acid, such as acrylic acid hydroxyethyl ester, acrylic acid hydroxypropyl ester, methacrylic acid hydroxyethyl ester and methacrylic acid hydroxypropyl ester, are preferably introduced.

The three components of the polyurethane resins containing vinyl groups according to the invention, namely diisocyanates, dihydroxy compounds and hydroxyalkyl esters of acrylic and / or methacrylic acid, are preferably introduced in the following ratios: 2 diisocyanate phthols are used per 1 mole of the dihydroxy compound and 2 moles of hydroxyalkyl ester of acrylic acid and / or methacrylic acid. However, deviations from this rule are possible, in particular, a larger number of the dihydroxy compound molecules can first be extended by reaction with diisocyanates before the molecule ends are loaded with acrylic and / or methacrylic acid hydroxyalkyl esters.

According to the invention, polyurethane resins containing vinyl groups are preferably prepared in the presence of known catalysts. Such catalysts are tertiary amines such as triethylamine, triethylamine, N-methylmorpholine, N * ethylmorpholine, N-cocomorpholine, Ν, Ν, Ν'-ether methyl ethylenediamine, 1,4-diaza-bicyclo- (2,2, 2) -N-methyl-N'-dimethylamino-ethyl-piperazine -acetate, Ν, Ν-dimethylbenzylamine, di- (N, N-dimethylaminoethyl) adipate, N, N-dimethylbenzylamine, five iomethylglimethylene triamine, Νumethyl, amina-dimethylbenzylamine Ν, Ν, Ν ', Ν-tetramethylO¹1,3-butanediamine, N, N-dimethyl - /? - phenylethylamine, 1,2-dimethylimidazole, 2-methylimidazole. Also used as catalysts are the known Mannich bases from secondary amines such as dimethylamine and aldehydes, preferably formaldehyde, or ketones such as acetone, methyl ethyl ketone, cyclohexanone, and phenols such as phenol, nonylphenol, bisphenol.

The tertiary amines with hydrogen atoms active towards isocyanate groups used as catalysts are, for example, compounds such as triethanolamine, trisopropanolamine, N-methyl diethanolamine, N-ethyldimethanolamine, Ν, Ν-dimethylethanolamine, and their reaction products with alkylene oxides such as propylene oxide and / or ethylene oxide.

In addition, silamihas having carbon-silicon bonds are used as catalysts, such as those described, for example, in German Patent Specification No. 1,229,290 (equivalent to U.S. Patent No. 3,620,984), e.g. trimethyl-2-silamorpholine, 1,3-diethylaminomethyl-tetramethyl-disiloxane.

Also used as catalysts are nitrogen-containing bases such as tetraalkylamine hydroxides, furthermore alkali metal hydroxides such as sodium hydroxide, alkali metal phenates such as sodium phenate, or alkali metal alkoxides such as sodium methoxide. Hexahydrotriazines can also be used as catalysts.

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Furthermore, organic metal compounds, in particular organic tin compounds, can also be used as catalysts. The stannous salts of karam acids are preferably used as organic tin compounds. boxylates such as stannous acetate, stannous heptane carboxylate, stannous ethylpentane carboxylate and stannous laurate, and also tin compounds, for example dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltinate, dibutyltinate^J. dibutyltin maleate or dioctyltin diacetate. Of course, it is also possible to use all the above-mentioned catalysts in the mixtures Apostate.

Further examples of suitable catalysts and details of their mode of operation are described in Kunststoff-Handbuch, Vol. VII, Vieweg and Hóchtlen, Carl Hanser, Munich, 1966, pp. 96-192. The catalysts are generally used in an amount of about 9.001-10% by weight, based on the total weight. J

In the preparation of the resins according to the invention, the dihydroxy compound is mixed with the hydroxyalkyl ester of acrylic acid and / or ethacrylic acid and reacted with the diisocyanate subsequently fed. In general, however, it is recommended that this procedure is first reacted with equimolar amounts of unsaturated hydroxyalkyl ester and a diisocyanate and then the precondensate is reacted with an oxyhydroxy compound. In principle, however, the procedure depends on the properties that the unsaturated uric acid must exhibit.

In order to prevent premature gelation of these masses and to guarantee storage properties, one or more polymerization inhibitors are preferably added during the production process. Suitable auxiliaries of this type in an amount of 9.991 to 0.1% by weight, based on the total mixture, are, for example, phenols and phenol derivatives, preferably spherically hindered phenols, which contain both ortho to the phenolic hydroxyl groups alkyl substituents with 1 to 6 carbon atoms, amines, especially secondary amines and their derivatives, quinones, cuprous salts of organic acids or products of attachment of cuprous halides to phosphites, and also phosphites as such.

Examples of such compounds are 4,4'-bis- (2,6-di-tertiary butylphenol), 1,3,5-trimethyl-2,4,6-tris- (3,5-di- Tertiary butyl-4-hydroxy-benzyl) -benzene, 4,4'-butylidene-bis- (6-tertiary butyl-m-cresol), 3,5-di-tertiary acid diethyl ester - tertiary .- butyl-4-hydroxybenzylphosphonic, N NN ^bis-Cj-naphthyl] -β-phenylenediamine. Ν, Ν'-bis- (1-methylheptyl) -p-phenylenediamine, phenyl- β-naphthylamine, 4,4'-bis- (α, α-dimethylbenzyl) -diphenylamine, 1,3,5-tris- ( 3,5-two-tertiary butyl-4-hydroxy-hydrocinnamoyl) - hexahydro-s-triazine, hydroquinone, p-benzoquinone, 2,5-two-tertiary butylquinone, toluhydroquinone, p-tertiary .butylpyrocatechin, 3-methylpyrocatechin, 4-tetylpyrocatechin, chlorines, naphthoquinone, copper naphthenate, copper heptanecarboxylate, cuprous chloride (triphenylphosphophyll, cuprous chloride) phosphorus^f trimethyl, cuprous chloride (tris-chloroethyl phosphite, cuprous chloride), tripropyl phosphite, p-nitrosodimethylaniline, triethyl phosphite.

Further suitable stabilizers are described in "Methoden der organischen Chemie" (Houben-Weyl), 4th Edition, Vol. XIV / 1, pp. 435-452, 756, Georg Thieme, Publishing House; Stuttgart, 1961. Phenothiazine is also a very good stabilizer.

The masses prepared from the above-described components in the above-described manner can be used as impression material in dentistry. During their hardening into shapes similar to rubber n2, the phenomenon of polymerization shrinkage is observed at all or only to a very small extent. 1 '· ->_f;

The hardening of these ointments is carried out with the aid of customary curing catalysts (for example as used for hardening so-called unsaturated polyester resins. Suitable polymerization starters are peroxides, optionally in the presence of accelerators such as aromatic amines or cobalt compounds. The elevated temperature curing can be carried out with peroxides alone or with radical starters such as azoisobutyric acid dinitrile, while room temperature curing requires the addition of accelerators. ₃0 preferably aromatic amines. The usual curing for polyurethane compositions containing vinyl fluids according to the invention can be carried out, for example, with the addition of 1% by weight of benzoyl peroxide and 1% by weight of N, N-dimethylaniline.

Curing may also be carried out by means of an energy-rich radiation, such as electron rays or gamma rays, or by means of ultraviolet light if ₄₀ photoinitiators are added to the resin. Suitable photoinitiator is, for example, benzophenone and its derivatives, benzoin and its derivatives such as benzoin ether, anthraquinone and aromatic disulfides.

When introducing polyurethane sand ₄₅ In dental practice, it is assumed that a certain viscosity is maintained, which must be selected in such a way that it is possible to use it in practice. The maintenance of the desired viscosity can be achieved to a large extent by means of the stoichiometry of the reaction components₅₀ in the synthesis of unsaturated urethane resins. It is also possible to influence the desired consistency by selecting the diluents and fillers in the desired manner. Diluents are, for example, inert organic solvents, such as hydrocarbons, toluene, xylene, and furthermore ethers, such as diethyl ether, ethylene glycols, and also liquid polyethers, alcohols, such as ethanol, butanol, octanol, glycol and glycerin. Particularly preferred diluents are the so-called plasticizers, such as are used, for example, in the treatment of polyvinyl chloride. For example, esters of phthalic acid or esters of adipic acid and esters of phosphoric acid can also be used. The phenyl esters of the alkali sulfonates are also preferred.

In some * * cases it may be advisable to use polymerizable vinyl monomers as diluents. For example, esters of acrylic acid, esters of methacrylic acid, styrene, vinyl acetate can be added. Preference is given to using acrylic acid esters such as acrylic acid isooctyl ester, acrylic acid dodecyl ester, 1,6-hexanaiol diacrylate, trimethylol propane triacrylate , ethylene glycol diacrylate and the corresponding methacrylic acid esters.

Other excipients mentioned are animal and vegetable fats, such as cottonseed oil, peanut oil, corn germ oil, olive oil, castor oil and sesame oil, moreover waxes, paraffin, polyethylene glycols, silicones, etc. In the case of fillers, reinforcing and / or non-reinforcing fillers can be used. Reinforcing fillers are understood to mean fillers; at least 50 m²/ g area. Examples include progressively produced silicon dioxide, silicon dioxide aerosols, calcium silicate, diatomaceous earth, titanium dioxide. As non-reinforcing fillers, quartz flour, sea sand, zirconium silicate, aluminum silicate, aluminum hydroxide, aluminum oxide, zinc oxide, gypsum, limestone, dolomite, hollow gypsum, chalk, as well as fillers of origin are mentioned.₍ organic material such as starch and powdered plastics such as powdered polyethylene, powdered polyvinyl chloride, powdered polyamide.

Mixtures of different fillers can also be included. The fillers are preferably used in an amount of 1 to 90% by weight, in particular 5 to 80% by weight, based on the total weight of the base materials.

Non-reinforcing fillers are preferably used in an amount greater than 10% by weight of the total weight.

The reinforcing fillers are preferably used in an amount of 1 to 10% by weight of the impression material. However, it can be used. also higher amounts of reinforcing fillers as long as the uniformity of the masses is not adversely affected.

The impression materials may also contain flavor and taste-improving additives, for example peppermint or eucalyptus oil, and sweeteners, for example saccharin. They can also be colored with organic dyes, as well as with organic or inorganic pigments.

Contrary to all other products used in impression materials to date, the new material has a special hardening behavior. Contrary to e.g. of polyethers and thiokols, the viscosity of which increases slowly immediately after the addition of the hardener components, this material changes only slightly during the treatment period required in dentistry, moreover, when, for example, polyethers and thiokols reach their final hardness only after about 30 minutes, the new material acquires its final hardness. final hardness immediately after the hardening is completed, i.e. in a much shorter time * after approx

4-5 mirftit. It should also be emphasized that the high desired degree of hardness, in contrast to thiokols and polyethers, is achieved with very little¹ participation of fillers. The specific properties of the resin-based impression compositions obtained by the method of the invention vary greatly depending on the selection of the appropriate starting materials, so that the mechanical properties and processing properties can be₍ adapted to all impression material applications.

In contrast to the hitherto used rubber-elastic impression materials, for example based on thiokols, the new material has an important advantage, namely that it is odorless. It should also be emphasized that these products have a very good adhesion or adhesive capacity, especially to metals and plastics, i.e. materials from which impression trays are made.

The finished impression material can be packaged both in pre-proportioned form and in larger quantities. The peroxide hardener can be added in liquid, solid or pasty form, and in the case of pasty hardeners any of the abovementioned auxiliaries and peroxide-stable fillers can be added. The hardener paste preferably has a consistency similar to the impression paste, and preferably the hardener is dosed in parallel with the base paste.

The new polyurethane resins containing vinyl groups are advantageously used in the field of dentistry. It is obvious, however, that their application is not limited to this field. They can be used wherever precise contour mapping is needed. The molds thus obtained can be filled in the usual manner with plaster or other casting materials to obtain a positive copy of the original object. .

The following examples explain the preparation and use of the new polyurethane resins containing vinyl groups.

EXAMPLE 1 581 g of hexamethylenediisocyanate are introduced into a 2-liter round bottom flask equipped with a dropping funnel, stirrer and air injection device, and a mixture of 504 g of hydroxypropyl methacrylate, 1.12 g of phenothiazine and 5.3 is slowly added while air is passed through at 60 ° C. g of tin heptane carboxylate solution (Desmorapid SN, Bayer AG). After completion of the exothermic reaction, this condensation product is introduced under stirring at 60 ° C while air is passed through 4559 g of a linear polyester of adipic acid and dimethylene glycol (molecular weight = 2100, hydroxyl number = 40 ± 5).

After 10 hours at 60 ° C, the content of the analytically determined NCO groups was 0.14%. After cooling the reaction product, a sticky resin is obtained.

Example II. Using a stoichiometric composition as in Example 1, hydroxypropyl methacrylate, a polyester with adipic acid is blended

113 841 and diethylene glycol, phenothiazine and tin heptane carboxylate and reacted with hexamethylene diisocyanate at 60 ° C while passing air through it. After 15 hours, a resin is obtained which is viscous at room temperature and which still shows 0.34% of free NCO groups by analysis.

Example III Analogously to Example I, 432 g of hydroxypropyl methacrylate, 1.7 g of phenothiazine, 5 g of tin heptane carboxylate solution, 485 g of hexamethylene diisocyanate and 5880 g of linear polyester made of adipic acid, butandiol and ethylene glycol (molecular weight = 4000, hydroxyl number = 28.6). After a reaction time of 10 hours, a viscous resin with a free isocyanate group content of 0.05% is obtained.

Example IV. Analogously to Example 2, 116 g of acrylic acid hydroxyethyl ester, 0.06 g of p-methoxyphenol, 1.0 g of triethylamine, 168 g of hexamethylene diisocyanate and 1000 g of linear polypropylene oxide (molecular weight = 2000 ± 100, hydroxyl number = 56) are reacted. ± 3). The result is a fluid resin having a viscosity of 2400 mPa · s.

EXAMPLE 5 By analogy with Example 1, 852 g of toluene-2,4-diisocyanate, 720 g of hydroxypropyl methacrylate, 0.5 g of p-methoxypheuol, 4 g of tin heptanecarboxylate solution and 3256 g of polyester from adipic acid and diethylene glycol (molecular weight) were reacted. = 2100, hydroxyl number = 40 ± 5). After 12 hours at 60^QC, a viscous resin is obtained in which the presence of free NCO groups can no longer be determined analytically.

Example VI. According to example / 1, 220 g of isophorone diisocyanate, 144 g of hydroxypropyl methacrylate, 0.53 g of phenothiazine and 1302 g of a polyester made of adipic acid and dimethylene glycol (MW = 2100, hydroxyl number = 40 ± 5) are reacted. After 24 hours at 60 ° C, a viscous resin with a free NCO content of 0.51% is obtained.

Example VII. 60 parts by weight of the resin described in Example 1 are mixed in a crusher with 20 parts by weight of talcum powder, 4 parts by weight of calcium silicate, 15.9 parts by weight of a linear polyester with a molecular weight of 2000 and 0.1 parts by weight of p-dimethyltoluidine for 1 hour.

parts by weight of the above paste are vigorously mixed for 30 seconds with 0.2 parts by weight of a paste consisting of 50% by weight of dibenzoyl peroxide and 50% by weight of dibutyl phthalate. Curing is complete after approximately 4 minutes. As a result of linear shrinkage measurement, the following results are obtained:

15’ = —0,013%

30 '= —0.007% lh = + 0.020%

6h = + 0.033%

24h = + 0.018%

Example VIII. 54 parts by weight of the resin described in Example 2 are mixed in a crusher with 37.8 parts by weight of talcum, 8.1 parts by weight of dioctyl phthalate and 0.1 part by weight of p-dimethyloxylidine for 1 hour.

parts by weight of the above-described paste are mixed with 2 parts by weight of a paste consisting of 4 parts by weight of 50% dibenzoyl peroxide in dibutyl phthalate, 61 parts by weight of talc and 35 parts by weight of dibutyl phthalate. The following hardness limits were obtained:

<td> 4’30”</td><td> : 58</td>

<td> 6’</td><td> : 60</td>

<td> 8’</td><td> : 60</td>

<td> 10’</td><td> : 61</td>

The linear shrinkage at 2 hours 30 minutes is 0.0294%.

Example IX. 44 parts by weight of the resin described in Example 3 are mixed in a crusher with 12 parts by weight of alkylsulfonic acid phenyl ester (MesamollR from Bayer AG), 12 parts by weight of a linear polyester with a molecular weight of 400, 22 parts by weight of talc, 5 parts by weight of polypropylene powder and 0, 1 parts by weight of dimethylaniline for 2 hours.

parts by weight of the above-described paste are mixed with 4 parts by weight of a paste consisting of 4 parts by weight of 50% dichlorobenzoyl peroxide in dibutyl phthalate, 60 parts by weight of annaline (burned gypsum) and 36 parts by weight of alkylsulfonic acid phenyl ester (MesamollR from Bayer AG). The following values ​​of linear contractility were found:

15’ = _0,037%

30 '= —0.060% lh = —0.075%

3h = —0.117%

6h = —0.126%

24h = —0.212%

Example 10 33.3 parts by weight of the resin prepared according to Example 3 and 7.4 parts by weight of the resin prepared according to Example 1, 9.3 parts by weight of alkylsulfonic acid phenyl ester (MesamollR from Bayer AG),

18.5 parts by weight of a linear 2000 molecular weight polyester, 18.5 parts by weight of talc,

12.9 parts by weight of powdered polyethylene and 0.1 parts by weight of p-dimethyltoluidine are mixed in a crusher for 4 hours.

parts by weight of the paste described above are mixed with 2 parts by weight of the peroxide paste described in Example 8. The following values ​​of linear contractility were found:

15’ :-0,013%

30 ': -0.007% lh: ± 0%

4h: + 0.009%

24h: -0.004%

The value of the sustained deformation is

1.11%, and the value of elastic deformation is 5.68%.