Dentistry material

The invention relates to impression materials for dentistry.

Impression materials are understood as meaning masses which change from a plastic to a hard or elastic state as a result of a hardening process. Impression materials are used in dentistry to obtain a congruent reproduction of the mucous membranes and the teeth. For this purpose, preference is given to using compositions which harden to a rubber-elastic consistency.

The production of rubber-elastic products can be done in various ways. In addition to the polymerization of unsaturated hydrocarbons having one or more double bonds, for example, the curing of thioplasts, which can be effected by the reaction of aqueous solutions of alkali metal polysulfides with aliphatic dihalides, leads to products with rubber-elastic properties. Further rubber-like products are produced by polycondensation of silicones. Another group of rubber-elastic products is achieved by the polyaddition reaction of a polyester or polyether with a diisocyanate.

The thiols have an unpleasant odor before and after crosslinking. Polyurethanes are not physiologically acceptable because they contain free isocyanate groups. Furthermore, all of these compositions show a relatively high polymerization shrinkage, which is attempted to be compensated for by the use of high filler fractions.

Furthermore, it is common to produce elastomeric rubber-like ethylene-dimer based compositions. Although these products are distinguished by relatively low polymerization shrinkage, they have the following disadvantages: In the case of water storage, larger volume changes occur due to swelling processes. The products are also physiologically unacceptable because they are cross-linked via aziridine end groups. In addition, some aziridines are known as carcinogenic substances.

All impression materials used in dentistry are limited in time both in terms of their processing time and their curing time. After formulation of the reactive mixture, a processing time of about 3 minutes is usually available; the subsequent curing time usually extends to about 5 min.

It has now surprisingly been found that certain polyurethane resins containing vinyl groups can be cold-cured to elastic rubber-like compositions within these times specified by the practice and that compositions containing these resins do not exhibit the abovementioned disadvantages when used as impression materials.

The impression materials according to the invention for dentistry, which harden after about 3 to 5 minutes to give a product having a rubber-elastic consistency

A) the reaction products

a) diisocyanates,

b) 2 hydroxyl-containing polyesters, polyethers, polythioethers, polyacetals, polycarbonates or polyesteramides, each having a molecular weight of 300 to 10,000, preferably 1000 to 8000, which may optionally contain urethane or urea groups, and

c) polymerizable vinyl compounds having an isocyanate-reactive hydrogen, wherein a), b) and c) are present in a molar ratio of about 2: 1: 2;

B) a curing catalyst,

C) 1 to 90 wt .-%, in particular 5 to 80 wt .-%, reinforcing and / or non-reinforcing fillers, and

D) optionally diluent to adjust the desired processing consistency.

In DE-OS 2427089 and 2426280 processes for the preparation of plastics from diisocyanates, dihydroxy compounds and oxypropyl methacrylate are described. Apart from the special formulation of these known plastics, these are highly cross-linked and impact resistant or hard and brittle, so that there is no connection with the rubber-elastic products producible with the impression materials according to the invention.

On a) As for the preparation of the resin component of the impression materials according to the invention

The diisocyanates which can be used in 3,376,988 are the following:

Ethylene diisocyanate, hexamethylene diisocyanate, cyclohexane-l, 4-diisocyanate, 2,4- and 2,6-toluene diisocyanate and mixtures thereof, isophororidiisocyanate, phorone diisocyanate, 1,5-naphthalene diisocyanate, 1,3-cyclopentylene diisocyanate, m- and p-phenylene diisocyanate, 2 , 4,6-tolylene triisocyanate, 4,4 ', 4-triphenylmethane triisocyanate,

1,3- and 1,4-xylylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-di-phenyl-methane diisocyanate, 3,3'-dimethylbiphenyl diisocyanate, 4,4'-bisphenylene diisocyanate Durene diisocyanate, 1-phenoxy-2,4'-phenylene diisocyanate, 1-tert-butyl-2,4-phenylene diisocyanate, methyl bis-4,4'-cyclohexyl diisocyanate, 1-chloro-2, 4-phenylene diisocyanate and 4,4 'di-phenylätherdiisocyanat.

Furthermore, it is possible to use relatively high molecular weight and optionally also higher functional polyisocyanates which are prepared from low molecular weight basic bodies by polymerization reaction to form uretdiones or isocyanurate derivatives. For example, the uretdione of 2 moles of 2,4-Toluylendiiso15 cyanate and the isocyanurate ring-containing polymerization of 2,4- and 2,6-toluene diisocyanate or hexamethylene diisocyanate, an average containing 2 isocyanurate rings in the molecule and formed from 5 moles of tolylene diisocyanate system, or a corresponding derivative mentioned on average 2 moles of toluene diisocyanate and 3 moles of hexamethylene diisocyanate.

It is also possible to prepare from di- or polyisocyanates by partial hydrolysis over the stage of carbamic acid and amine higher urea or biuret linked systems, such as a biuret-linked compound formally from 3 moles of hexamethylene diisocyanate with the addition of 1 mole of water and elimination of 1 mole of carbon dioxide has formed.

Likewise suitable isocyanate group-containing substances are obtained in the reaction of diols or polyols with di- or polyfunctional isocyanates, if the molar ratio of hydroxy compound to isocyanate is chosen so that in the statically formed reaction products always free NCO functions remain present and a molecular weight of 2000 until 3000 is not exceeded.

Particularly preferred isocyanate-containing compounds which can be used in the resins according to the invention are hexamethylene diisocyanate, tolylene diisocyanate, isophorone diisocyanate and 4,4'-diphenylmethane diisocyanate.

B) Further components for the resin component of the molding compositions according to the invention are compounds having two isocyanate-reactive groups

Hydrogen atoms having a molecular weight of 300 to 10,000, but preferably from 1000 to 8000.

By means of these compounds is meant, in addition to amino groups, thiol groups or carboxyl-containing compounds, preferably polyhydroxyl compounds, especially compounds having from two to eight hydroxyl groups, especially those of molecular weight 300 to 10,000, preferably 1,000 to 8,000, eg usually two hydroxyl-containing polyesters, polyethers, Polythioäther, polyacetals, polycarbonates and polyester amides, as are known for the preparation of homogeneous and cellular polyurethanes.

The eligible hydroxyl-containing polyesters are, for example, reaction products of polyvalent, preferably dibasic and optionally additionally trivalent products

Alcohols with polybasic, preferably dibasic, carboxylic acids. Instead of the free polycarboxylic acids and the corresponding polycarboxylic anhydrides or corresponding

Polycarboxylic acid esters of lower alcohols or mixtures thereof are used to prepare the polyesters. The polycarboxylic acids may be aliphatic, cycloaliphatic, aromatic and / or heterocyclic in nature and optionally substituted, for example by halogen atoms and / or unsaturated.

Examples which may be mentioned are: succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid, phthalic anhydride, tetrahydrophthalic acid No. 3,776,988

4-anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, dimeric and trimeric fatty acids such as oleic acid, optionally in admixture with monomeric fatty acids, dimethyl terephthalate and bis-glycol terephthalate. As polyhydric alcohols come, for example Ethylene glycol, propylene glycol (1,2) and - (1,3), butylene glycol (1,4) and - (2,3), hexanediol (1,6), octanediol (1,8), neopentyl glycol, Cyclohexanedimethanol (1,4-bis-hydroxymethylcyclohexane), 2-methyl-1,3-propanediol, glycerol, trimethylolpropane, hexanetriol (1,2,6), butanetriol (1,2,4), trimethylolethane, pentaerythritol, quinitol , Mannitol and sorbitol, methyl glycoside, furthermore diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, polypropylene glycols, Dibutylene glycol and polybutylene glycols in question. The polyesters may have proportionately terminal carboxyl groups. It is also possible to use polyesters of lactones, for example ε-caprolactone or hydroxycarboxylic acids, for example ε-hydroxycaproic acid.

Also, the candidate, usually two hydroxyl groups having polyethers are those of the known type and are, for example, by polymerization of epoxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin with itself, for example in the presence of BF₃, or by addition of these epoxides, optionally in admixture or in succession, to starting components with reactive hydrogen atoms such as water, alcohols, ammonia or amines, for example ethylene glycol, propylene glycol- (1,3) or - (1,2), 4,4'- Dihydroxy-diphenylpropane, aniline, ethanolamine produced. In many cases, preference is given to those polyethers which predominantly (up to 90% by weight), based on all OH groups present in the polyether, have primary OH groups. Polyethers modified by vinyl polymers, such as are formed, for example, by polymerization of styrene and acrylonitrile in the presence of polyethers [ÜS-PS No. 3,383,351, No. 3,304,273, No. 3,523,093, No. 3,110,695, DE-PS No. 1,155,236], are also suitable , as well as OH-containing polybutadienes.

Among the polythioethers, mention may be made in particular of the condensation products of thiodiglycol with itself and / or with other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or aminoalcohols. Depending on the CO components, the products are polythiomous ethers, polythioether esters or polythioetheresteramides.

Examples of suitable polyacetals are the compounds which can be prepared from glycols, such as diethylene glycol, triethylene glycol, 4,4'-dioxethoxydiphenyldimethylmethane, hexanediol and formaldehyde. Also by polymerization of cyclic acetals can be produced according to the invention suitable polyacetals.

As hydroxyl-containing polycarbonates, those of the known type are suitable, for example, by reacting diols such as propanediol (1,3), butanediol (1,4) and / or hexanediol (1,6), diethylene glycol, triethylene glycol or tetraethylene glycol with diaryl carbonates, eg diphenyl carbonate, or phosgene can be prepared.

Examples of polyester amides and polyamides include those obtained from polybasic saturated and unsaturated carboxylic acids or their anhydrides and polybasic saturated and unsaturated aminoalcohols, diamines, polyamines and mixtures thereof, predominantly linear condensates.

Also already containing urethane or urea groups polyhydroxyl compounds and optionally modified natural polyols, such as castor oil, carbohydrates or starch, are usable. Addition products of alkylene oxides to phenol-formaldehyde resins or to urea-formaldehyde resins can be used according to experience.

Of course, mixtures of the abovementioned compounds with generally two isocyanate-reactive hydrogen atoms having a molecular weight of from 300 to 10,000, for example mixtures of polyethers and polyesters, can be used.

C) The third component of the resin constituent of the impression materials according to the invention is polymerizable vinyl compounds having an isocyanate-reactive hydrogen. Preference is given to the use of alkoxylation products of acrylic and / or methacrylic acid, such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.

Nr.376988

The three components from which the vinyl group-containing polyurethane compositions which form the resin constituent of the impression materials according to the invention are constructed, namely diisocyanates, dihydroxy compounds and oxyalkyl esters of acrylic and / or methacrylic acid, are preferably reacted with one another in the following stoichiometry: 1 mole of the dihydroxy compound, 2 moles of diisocyanate and 2 moles of the oxyalkyl esters of acrylic and / or methacrylic acid are used. However, deviations from this rule are quite possible: In particular, several molecules of the dihydroxy compound can first be extended by reaction with diisocyanates before the ends are reacted with the oxyalkyl ester of acrylic and / or methacrylic acid.

Advantageously, the preparation of the resin component of the impression materials of the invention takes place in the presence of known catalysts. As such are for example in question:

Tertiary amines, such as triethylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, N-cocomorpholine, N, N, N'-tetramethylethylenediamine, 1,4-diazabicyclo- (2,2,2) -octane, N-methyl-N'-dimethylamino-ethyl-piperazine, N, N-dimethylbenzylamine, bis (N, N-diethylaminoethyl) -adipate, N, N-diethylbenzylamine, pentamethyldiethylenetriamine, N, N'-dimethylcyclohexylamine, N, N, N ' , N'-tetramethyl-1,3-butanediamine, N, N-dimethyl-.beta.-phenylethylamine, 1,2-dimethylimidazole, 2-methylimidazole. Suitable catalysts are also known Mannich bases of secondary amines, such as dimethylamine, and aldehydes, preferably formaldehyde, or ketones, such as acetone, ethyl ethyl ketone, cyclohexanone and phenols, such as phenol, nonylphenol, bisphenol in question.

For example, triethanolamine, triisopropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N, N-dimethylethanolamine, and their reaction products with alkylene oxides, such as propylene oxide and / or ethylene oxide, are catalysts for isocyanate-active hydrogen atoms.

Further suitable catalysts are silylamines having carbon-silicon bonds, as described, for example, in DE-PS No. 12229290 [corresponding to US Pat. No. 3,620,984], for example 2,2,4-trimethy 1 -2- silylmorpholine, 1,3-diethylaminomethyltetramethyl, 1 -disiloxane.

Suitable catalysts are also nitrogen-containing bases such as tetraalkylammonium hydroxides, furthermore alkali metal hydroxides such as sodium hydroxide, alkali metal phenolates such as sodium phenolate or alkali metal alcoholates such as sodium methylate. Hexahydrotriazines can also be used as catalysts.

Furthermore, organic metal compounds, in particular organic tin compounds, can also be used as catalysts.

Tin (II) salts of carboxylic acids such as tin (II) acetate, tin (II) octoate, tin (II) ethyl hexoate and tin (II) laurate and the tin (IV) compounds are preferably used as organic tin compounds. eg dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate or dioctyltin diacetate. Of course, all the catalysts mentioned above can be used as mixtures.

Further representatives of suitable catalysts as well as details of the mode of action of the catalysts are described in Kunststoff-Handbuch, Volume VII, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich, 1966, eg on pages 96 to 102.

The catalysts are usually used in an amount between about 0.001 and 10 wt .-%, based on the total amount.

In the preparation of the resin component of the impression materials according to the invention, the dihydroxy compound can be mixed with the oxyalkyl ester of acrylic and / or methacrylic acid and reacted with the subsequently introduced diisocyanate. In general, however, a reaction is recommended in which initially equimolar amounts of the unsaturated oxyalkyl ester and of the diisocyanate are reacted with each other, whereupon this precondensate is reacted with the dihydroxy compound in the following. In principle, however, the procedure depends on the properties that the unsaturated urethane composition should possess.

In order to avoid premature gelling of these compositions and to guarantee shelf life, it is expedient to add one or more polymerization inhibitors already during production. Suitable auxiliaries of this kind, which can be added in amounts of from 0.001 to 0.1% by weight, based on the total mixture, are, for example, phenols and phenol derivatives, preferably sterically hindered phenols which have alkyl substituents in both ortho positions to form phenolic hydroxyl groups. 6 C atoms, amines, preferably secondary aryl amines and their derivatives, quinones, copper I salts of organic acids or addition compounds of copper (I) halides to phosphites, but also phosphites alone.

Namely, may be mentioned: 4,4'-bis (2,6-di-tert-butylphenol), l, 3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl) 4-hydroxybenzyl) benzene, 4,4'-butylidene bis (6-tert-butyl-m-cresol), diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, N, N'-bis -fe-naphthyl) -p-phenylenediamine, N, N'-bis (1-methylheptyl) -p-phenylenediamine, phenyl-g-naphthylamine; 4,4'-Bis (a, a -dimethylbenzyl) -diphenylamine, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxy-hydrocinnamoyl) -hexahydro-s-triazine, hydroquinone , p-benzoquinone, 2,5-di-tert-butyl-quinone, toluhydroquinone, p-tert-butylcatechol, 3-methylcatechol, 4-ethylcatechol, chloranil, naphthoquinone, copper naphthenate, copper octoate, Cu (I) Cl / triphenyl phosphite, Cu (I. ) C1 / trimethyl phosphite, Cu (I) Cl / trichloroethyl phosphite, Cu (I) Cl / tripropyl phosphite, p -nitrosodimethylaniline, triethyl phosphite.

Further suitable stabilizers are described in Methods of Organic Chemistry (Houben-Weyl), 4th Edition, Volume XIV / 1, pages 433 to 452, 756, Georg Thieme Verlag, Stuttgart, 1961.

Another very suitable stabilizer is phenothiazine.

The impression materials for dentistry according to the invention produced from the abovementioned components in the manner described prove to be particularly suitable for this purpose, since no or only an extremely low polymerization shrinkage is observed when they are cured into rubber-like shaped bodies.

The curing of the impression materials of the invention is carried out with the usual curing catalysts, as used for example for the curing of so-called unsaturated polyester resins. Suitable polymerization initiators are peroxides, optionally in the presence of accelerators such as aromatic amines or cobalt compounds. While cure at elevated temperature may be accomplished by peroxyde alone or radical initiators such as azoisobutyrodinitrile, room temperature cure requires the addition of accelerators, preferably aromatic amines. A typical curing can be carried out, for example, by adding 1% by weight of benzoyl peroxide and 1% by weight of N, N-dimethylaniline.

It is also possible to cure with energy-carrying rays such as electron beams or gamma rays or, if photoinitiators are added to the resin, with UV light. Examples of suitable photoinitiators are benzophenone and its derivatives, benzoin and its derivatives, such as benzoin ethers, anthraquinones and aromatic disulfides.

For the use of the impression materials according to the invention in the dental practice, a certain viscosity behavior is a prerequisite. This must be such that a practical application is possible. Such a desired viscosity behavior can be achieved largely by stoichiometry and reactants in the synthesis of the unsaturated urethane resins. It is also possible to influence the desired processing consistency by matching diluents and fillers in the desired manner. Suitable diluents are, for example: inert organic solvents such as hydrocarbons, toluene, xylene, further ethers such as diethyl ether, ethylene glycols, but also liquid polyethers, alcohols such as ethanol, butanol, octanol, glycol or glycerol. Particularly preferred diluents are so-called plasticizers, as used for example in the processing of polyvinyl chloride. For example, esters of phthalic acid or esters of adipic acid and esters of phosphoric acid can be used here. Also suitable are phenyl esters of alkanesulfonates.

In special cases, it may be appropriate to use copolymerizable vinyl monomers as diluents. For example, it is possible to add: esters of acrylic acid, esters of methacrylic acid, styrene, vinyl acetate. Preferred esters of acrylic acid are isooctyl acrylate, dodecyl acrylate, hexane diol 1,6-diacrylate, trimethylolpropane triacrylate, ethylene glycol diacrylate and the corresponding esters of methacrylic acid.

Nr.376988

As further formulation auxiliaries may be mentioned: animal and vegetable fats such as cottonseed oil, peanut oil, corn oil, olive oil, castor oil and sesame oil, waxes, paraffin, polyethylene glycols, silicones, etc.

The fillers may be reinforcing and / or non-reinforcing fillers 5. Reinforcing fillers are understood as meaning those fillers that are at least 50 m long²/ g have surface. Examples which may be mentioned are: pyrogenically produced silicon dioxide, silicon dioxide aerogels, calcium silicate, diatomaceous earth, titanium dioxide. As non-reinforcing fillers may be mentioned: quartz powder, sea sand, zirconium silicate, aluminum silicate, aluminum hydroxide, aluminum oxide, zinc oxide, gypsum, limestone, dolomite, dead burned gypsum, chalk, but also fillers organic

Origin, such as starches and plastic powders, such as polyethylene powder, PVC powder, polyamide powder.

It is also possible to use mixtures of different fillers. The fillers are preferably used in amounts of from 1 to 90% by weight, in particular from 5 to 80% by weight, based on the total weight of the respective base materials.

Non-reinforcing fillers are preferably used in amounts greater than 10% by weight of the

Total mass used.

Reinforcing fillers are preferably used in amounts of 1 to 10 wt .-% of the respective impression material. However, larger amounts of reinforcing fillers can be used as long as the mixing unit of the masses does not suffer.

The. Molding compositions according to the invention can also improve odor and flavor

Additives, for example peppermint oil or eucalyptus oil and sweeteners, such as saccharin. They can be colored with both soluble organic dyes and organic or inorganic pigments.

In contrast to all other products previously customary for impression materials, the material according to the invention is distinguished by a particular hardness behavior. In contrast to eg polyethers and Thiokolen, whose viscosity increases slowly immediately after the addition of the curing components, the material of the invention changes only slightly during the dental fixed processing width, while, for example Polyether and Thiokole their final Shorehär th only after about 30 min, the final Shore hardness in the material according to the invention already after the end of curing, ie in a much shorter time, after 4 to 5 min before. It is also worth noting that a high desirable Shore hardness, in contrast to Thiokolen and polyethers even with very low filler contents in the composition of the invention is achieved. The specific properties of the impression materials according to the invention are very variable by choice of suitable starting materials, so that the mechanical properties and the processing properties can be adjusted to all impression material applications.

Compared to the previously used rubber-elastic impression materials, for example based on Thiokol, the material according to the invention has the significant advantage of odorlessness. Of particular note is the very good adhesion or adhesiveness of the products according to the invention, in particular to metals and plastics, materials which are used for the production of impression trays.

The packaging of the finished impression materials can be pre-proportioned as well as in larger quantities. The addition of peroxygenic curing can be done either in liquid, solid or pasty form, with pasty hardeners can be used against all 45 Peroxde resistant, above-mentioned auxiliaries and fillers. Preferably, the hardener paste has a similar consistency as the impression paste, and preferably the dosage of the harder is in the same strand length as the stock paste.

The new vinyl-containing polyurethane resins according to the invention as impression-containing impression materials are used in the dental field. But it goes without saying that their use is not limited to this; Rather, they can be used wherever an accurate impression of contours is required. The molds thus obtained may be filled with plaster or other pouring materials, as is customary in the art, to obtain a positive copy of the originally molded article.

Nr.376988

In the following examples, the preparation and the use according to the invention of the vinyl-containing polyurethane resins according to the invention as impression materials containing resin constituents are explained in greater detail.

Preparation of the resin component:

Preparation 1:

In a 2-1 round bottom flask with drip funnel, stirrer and the introduction device for air 581 g of hexamethylene diisocyanate are introduced and mixed slowly with air at 60 ° C with a mixture of 504 g of oxypropyl methacrylate, 1.12 g of phenothiazine and 5.3 g Zinnoctoatlösung , After the exothermic reaction has subsided, this condensation product is stirred at 60 ° C. while passing air into 4559 g of a linear polyester of adipic acid and diethylene glycol (MW = 2100, hydroxyl number = 40 ± 5). After a reaction time of 10 h at 60 ° C, the analytically detectable content of NCO groups was 0.14%. After cooling the reaction product, a viscous resin resulted.

Preparation 2:

In the same stoichiometric composition as in Preparation 1, hydroxypropyl methacrylate, the polyester of adipic acid and diethylene glycol, phenothiazine and tin octoate are mixed and reacted at 60 ° C. while passing air through with hexamethylene diisocyanate. After a reaction time of 15 h, a viscous, viscous resin at room temperature results, in which 0.34% of free NCO groups could be analytically detected.

Preparation 3:

Analogously to Preparation 1, 432 g of oxypropyl methacrylate, 1.7 g of phenothiazine, 5 g of tin octoate solution, 485 g of hexamethylene diisocyanate and 5880 g of a linear polyester of adipic acid, butanediol and ethylene glycol (MW = 4000, hydroxyl number = 28.6) are reacted. The result after 10 hours of reaction time, a viscous resin with a content of free isocyanate groups of 0.05%.

Preparation 4:

According to Preparation 1, 116 g of ethyl acrylate, 0.06 g of p-methoxyphenol, 1.0 g of triethylamine, 168 g of hexamethylene diisocyanate and 1000 g of a linear polypropylene oxide (MW = 2000 ± 100, hydroxy number = 56 ± 3) are reacted. The result is a low-viscosity resin with a viscosity of 2400 cP.

Preparation 5:

Analogously to preparation 1, 852 g of tolylene 2,4-diisocyanate, 720 g of oxypropyl methacrylate, 0.3 g of p-methoxyphenol, 4 g of tin octoate solution and 3256 g of a polyester of adipic acid and diethylene glycol (MW = 2100, hydroxyl number = 40 ± 5) were reacted , After 12 h reaction time at 60 ° C results in a viscous resin in which analytically no free NCO groups can be detected.

Preparation 6:

According to Preparation 1, 220 g of isophorone diisocyanate, 144 g of oxypropyl methacrylate, 0.33 g of phenothiazine and 1302 g of a polyester of adipic acid and diethylene glycol (MW = 2100, hydroxyl number = 40 ± 5) are reacted. After 24 h at 60 ° C results in a viscous resin with a content of free NCO groups of 0.51%.

Production and use of the impression materials:

Example 1: 60% by weight of the resin prepared according to preparation 1 were mixed in a kneader with 20 parts by weight of talc, 4 parts by weight of calcium silicate, 15.9 parts by weight of a linear polyester having a molecular weight of 2000 and 0, 1 part by weight of p-dimethyltoluidine mixed for 1 h.

Parts by weight of the resulting paste were vigorously mixed with 0.2 parts by weight of a paste consisting of 50% by weight of dibenzoyl peroxide and 50% by weight of dibutyl phthalate for 30 seconds. The

<td colspan="3">Curing was completed in about 4 minutes. The measurement of the linear shrinkage gave the following</td>

<td>Values:</td><td>15 ':</td><td>-0.013%</td>

<td></td><td>30 ':</td><td>-0.007%</td>

<td></td><td>lh:</td><td>+ 0.020%</td>

<td></td><td>6h:</td><td>+ 0.033%</td>

<td></td><td>24 hours:</td><td>+ 0.018%</td>

- 9 No.376988

Example 2 54 parts by weight of the resin obtained in Preparation 2 were mixed in a kneader with 37.8 parts by weight of talc, 8.1 parts by weight of dioctyl phthalate and 0.1 part by weight of p-dimethylxylidine for 1 hour ,

Parts by weight of the resulting paste were 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

Parts by weight dibutyl phthalate mixed. The following shore hardnesses were measured:

<td></td><td>4 '30</td><td>: 58</td>

<td></td><td>6 '</td><td>: 60</td>

<td></td><td>8th'</td><td>: 60</td>

<td>10</td><td>10 '</td><td>: 61</td>

The shrinkage value was measured linearly after 2 h 30 'at 0.0294%.

Example 3: 44 parts by weight of the resin obtained according to Preparation 3 were mixed in a kneader with 12 parts by weight of phenylsulfonylphenyl ester, 12 parts by weight of a linear polyester having 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 mixed for 2 h.

Parts by weight of the resulting paste were mixed with 4 parts by weight of a paste consisting of 4 parts by weight Dichlorbenzoylperoxyd 50% in dibutyl phthalate, 60 parts by weight of dead burned gypsum and 36 parts by weight Alkylsulfonsäurephenylester.

The following linear shrinkage values ​​were found:

15 ': -0.037%

30 ': -0.060% lh: -0.075%

3h: -0.117%

6h: -0.126%

24h: -0.212%

Example 4: 33.3 parts by weight of the resin obtained according to Preparation 3 and 7.4 parts by weight of the resin obtained according to Preparation 1, and 9.3 parts by weight Alkylsulfonsäurephenylester, 18.5 parts by weight of a linear Polyester having a molecular weight of 2000, 18.5 parts by weight of talc, 12.9 parts by weight of polyethylene powder and 0.1 part by weight of p-dimethyltoluidine were in a kneader

4 h mixed.

Parts by weight of the resulting paste were mixed with 2 parts by weight of the peroxide paste described in Example 2. The following values ​​were found for the linear fading:

<td>15 '</td><td>: -0.013%</td>

<td>30 '</td><td>: -0.007%</td>

<td>lh</td><td>: ± 0%</td>

<td>4h</td><td>: + 0.009%</td>

<td>24 hours</td><td>: -0.004%</td>

For the permanent deformation a value of 1,11% was found and for the elastic deformation a value of 5,68%.