DE4025776A1 - New curable prepolymers prepn. - from diol-or di:amino-terminated poly:tetra-hydro-furan with di:isocyanate and hydroxy-or amino-acrylate or with isocyanato-acrylate - Google Patents

Abstract

Prepolymers (I) are obtd. by reacting (A) polyether diol or polyether diamine of formula H-X1-PE-X1-H (where X1 = O, NH or NR, where R = 1-4C alkyl; PE = polyether residue consisting at least partly of polytetrahydrofuran units) with (B) di-isocyanate of formula OCN-A1-NCO (where A1 = opt. substd. 2-30C hydrocarbon gp.) and (C) monomeric hydroxy- and/or amino-functional deriv. of acrylic and/or methacrylic acid, of formula H-X2-R1-O-C(O)-C(R2)=CH2 (where X2 = O, NH or NR; R1 = 2-3C alkylene; R2 = H or Me) or by reacting (A) with (D) monomeric, isocyanate-functional deriv. of acrylic and/or methacrylic acid, of formula OCN-R1-O-C(O)-C(R2)=CH2. USE/ADVANTAGE - (II) is used as adhesive, sealant or potting material partic. bonding articles or surfaces of polycarbonate with articles or surfaces of polycarbonate or other material. (II) harden quickly, are economical in materials, have low shrinkage, and give durable bonds with polycarbonates.

Description

The invention relates to prepolymers based on bifunctional Polyether derivatives, the urethane and / or Ureidgruppen and contain polymerizable, ethylenically unsaturated groups. The invention also relates to curable compositions containing these Contain prepolymers and preferably photocurable and are solvent-free. The curable compositions are preferably used as adhesives, sealants or investments.

The use of new materials of different kinds in the Industrial production requires the increasing amount Use of adhesives and sealants in the connection of parts made of these materials. The advantages of Joining techniques are often due to inadequate material properties  used as adhesives and sealants Polymers diminished. Particularly critical z. B. the storage stability the adhesives and the weathering resistance and the long term behavior of the bonding material in the glue joint. In particular, plastics can be combined with others Materials such. Metal, glass, ceramics and the like, in terms of storage stability, weathering resistance and long-term behavior often insufficient connect. For example, there is a long-unmet Need for an adhesive with which Polycarbonates with other materials permanently and in each Respectfully connect.

DE-OS 23 24 822 are photopolymerizable polymers known by reaction of an organic di- or Polyisocyanate with an acrylate or methacrylate available are, whose ester component is a hydroxyl or amino group having. By (poly) addition of the acrylate to diisocyanate groups arise oligomers, the urethane and / or Ureidgruppen respectively. Leave from these known compounds by addition of polymerization initiators, accelerators, Inhibitors, diluents, thickeners, other means for adjusting the viscosity, plasticizers and produce such radically curable compositions, which are used as UV-curable adhesives. These known Adhesives possess due to their photosensitivity even with careful dark storage only an insufficient Storage stability. The very fast curing under UV irradiation leads to hard and brittle polymers, when gluing various materials occurring Temperature change voltages not in sufficient Withstand the dimensions. In addition, remain by the pronounced Oxygen inhibition (scavenging of free radicals by oxygen molecules the air) undesirable smear layers the surface of the cured polymers.  

In DE-AS 17 45 063 are under anaerobic conditions rapidly curing sealing compounds described in the same or very similar constructed monomers, as they from DE-OS 23 24 822 are known by (poly) addition of hydroxy and amino functional acrylates to polyisocyanates are available. Especially if they are in thicker Layers are processed, these are sealing compounds often too hard after hardening and therefore brittle and sticky insufficiently to be connected or sealed Substrates.

The invention is based on the object, prepolymers and to provide curable compositions prepared therefrom, which are the To enable the production of firm and permanent bonds and through improved flexibility, elasticity and stretchability the polymers in the cured state an improved Thermal shock resistance and resistance have over other mechanical stresses. The polymerizable compositions should also be used as sealing material can be used quickly and harden gently and as little shrinkage as possible polymerize. When cured, the masses should to be as inert as possible to solvents, to be durable to allow non-swelling seals or adhesions. The substrates to be connected to the masses should neither chemically nor by the curing mechanism negative to be influenced. Finally, the invention is the task basis, an effective means of permanent enrichment and bonding of polycarbonates.

This object is achieved by the prepolymers according to one of the claims 1 to 7, by the curable Compositions according to one of the claims 8 to 14 and by the use according to one of the claims 15 and 16 solved.  

The prepolymers of the invention based on bifunctional Polyether derivatives are available by reaction

• (A) a polyether diol or polyether diamine of the formula H-X₁-P-X₁-H (I) wherein X₁ represents an oxygen atom, NH or NR and R is an alkyl group having 1 to 4 C atoms and the polyether P is at least partially made of polytetrahydrofuran Units exists,
• (B) with a diisocyanate of the formula O = C = N-A₁-N = C = O (II) wherein A₁ is an optionally substituted hydrocarbon radical with 2 to 30 carbon atoms, and
• (C) with a monomeric, hydroxy and / or amino-functional derivative of acrylic and / or methacrylic acid of the formula wherein
  X₂ is an oxygen atom, NH or NR and R is an alkyl group having 1 to 4 C atoms,
  R¹ is a C₂-C₄-alkylene group and
  R² is H or CH₃,

or by reacting (A) and (D), wherein

• (D) a monomeric, isocyanato-functional derivative of acrylic and / or methacrylic acid of the formula with the meanings given for formula (III) for the radicals R¹ and R².

Preference according to the invention are those prepolymers, by Reaction of components (A), (B), (C) in the ratio A: B: C = 1: 2: 2 are available. These preferred prepolymers correspond of formula (V):

wherein P, A₁, X₁, X₂, R¹ and R² are as indicated above Own meanings.

As component (A) according to the invention is preferably a Polyether diol or diamine with an average Molecular weight of 1000 to 20,000 used. In the bifunctional Polyether derivative may be a homopolymer, a block copolymer or a copolymer to act with an irregular sequence of chain components. In any case, the bifunctional polyether derivative must at least partially consist of polytetrahydrofuran units. Preferably, it is a polytetrahydrofuran (PTHF) - Homopolymer of 4 to 200, more preferred with 10 to 100 [- (CH₂) ₄-O -] units (average Chain length in the oligomer or polymer molecule).

When as component (A) a bifunctional block copolymer is used, it is preferably such with structural elements of the formula

wherein
R³ is an alkylene or isoalkylene radical having in each case 2 to 4 C atoms and
y, z, which may be the same or different, are each an integer from 2 to 100, preferably from 5 to 50
mean.

Finally, as component (A) a copolymer of Tetrahydrofuran and an alkylene oxide with irregular distribution be used by - [(CH₂) ₄O] - and (R³O) units, wherein R³ has the meanings given above and is preferably an ethylene, propylene or butylene radical.

The definitions given for component (A) with the Formula (I) includes bifunctionally-substituted polytetrahydrofuran in which the two hydroxyl or amino groups (-X₁-H) not directly to tetramethylene oxide units of Polyethers are bound, but each to another Alkylene oxide group (-R³O-), with which the ends of (poly) - Tetramethylene oxide chains have been previously modified.

As component (A) suitable commercial products are, for. B. the Polytetrahydrofuran homopolymers PTHF 650, PTHF 1000 and PTHF 2000 from BASF, copolymers of tetrahydrofuran with other alkylene oxides, such as POLYRAN from Bayer AG, irregular copolymers of THF with ethylene oxide, poly- THF-diamine such as PTHF-diamine 5200 and bis (3-aminopropyl) - PTHF-diamine 2100 from BASF.

As component (B) are preferably such diisocyanates of formula (II) wherein A₁ is an aliphatic, cycloaliphatic or aromatic or a mixed one aliphatic-cycloaliphatic or a mixed aromatic aliphatic hydrocarbon radical, optionally with alkyl, alkoxy and carboxyl groups each having 3 to 6 Carbon atoms and / or with halogen atoms (F, Cl, Br and I) may be substituted. Particularly preferred are diisocyanates of the formula (II) used, wherein A₁ is an optionally  substituted alkyl group having 1 to 12 carbon atoms is.

Diisocyanates of the formula (II) which are suitable for the preparation of the prepolymers according to the invention are, for example, ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and 1,4-diisocyanate, tolylene diisocyanate, 4 , 4'-diphenyl diisocyanate, 4,4'-diphenylene methane diisocyanate, p-phenylene diisocyanate, trimethylene diisocyanate, nonamethylene diisocyanate, octamethylene diisocyanate, 2-chloropropane diisocyanate, isophorone diisocyanate, 3-heptene diisocyanate, tetrachlorophenylene diisocyanate-1,4, trans-phenylene diisocyanate, phoron diisocyanate, 1,5-naphthalene diisocyanate , 1,3-cyclopentylene diisocyanate, 1,4-xylylene diisocyanate, 3,3-dimethylbiphenylene diisocyanate, bis (isocyanato) tricyclo [5.2.1.0 ^2,6 ] decane.

Hydroxyl-containing and amino-containing derivatives of Acrylic acid and methacrylic acid used as component (C) for Preparation of the prepolymers of the invention are suitable, are, for example, hydroxyethyl acrylate, hydroxyethyl methacrylate, Aminoethyl methacrylate, 3-hydroxypropyl methacrylate, Aminopropyl methacrylate, hydroxyhexyl acrylate, Tert-Butylaminoethylmethylacrylat and hydroxyoctyl methacrylate.

Suitable components (D) are, for example, isocyanatoethyl methacrylate or isocyanatopropyl methacrylate.

In the preparation of the prepolymers of the invention takes place the reaction of components (A), (B) and (C) or (A) and (D) at -10 to + 100 ° C, preferably at 0 to 20 ° C. The reaction may be carried out in a suitable solvent, for example in dichloromethane, carried out takes place but preferably without the addition of a special solvent.  The reaction can also be carried out using catalysts, for example, organic tin compounds such as Dibutyltin dilaurate, carried out, but can also without addition a catalyst can be carried out.

The prepolymers of the invention preferably contain at least 2 to 10 urethane groups and 0 to 10 ureide groups. The total number of urethane and ureide groups is preferably 2 to 6, more preferably 4 per prepolymer molecule. Particularly advantageous is a number of each 2 urethane and 2 ureide groups per molecule proved.

The ratio between the molecular weight and the number the carbonyl group adjacent to a nitrogen atom in the prepolymer molecule according to the invention preferably 100 to 1000.

The producible from the prepolymers of the invention hardenable masses comprise at least one of these Prepolymers at least one copolymerizable with the prepolymer Diluent monomer, which both the setting of the desired viscosity as well as to modify the chain length the polymers is used, and contains the curable composition a hardener system for either radical polymerization or the anaerobic cure or for by actinic radiation or photo-induced curing and optionally further additives such as adhesion improvers, Polymerization inhibitors and other common Auxiliaries and additives, among which fillers, pigments, Odorants and the like are to be understood.

As copolymerizable diluent monomers are preferably those from the group of vinyl monomers and hydroxy-functional Derivatives of acrylic acid and methacrylic acid, for example, hydroxyethyl acrylate or hydroxypropyl methacrylate, selected. As Verdünnungsmonomere can thus Compounds are used simultaneously as well  Component (C) for the preparation of the prepolymers of the invention can be used.

This results in the advantage that the components (A), (B) and (C) in the preparation of the prepolymers also in the Way can be reacted with each other, that the component (C) is added in excess, so that the excess Proportion of the functional derivative of acrylic acid or At least partially methacrylic acid in the resulting prepolymer copolymerized and thus the chain extension serves, at least in part but also unchanged in the reaction mixture remains and thus as Verdünnungsmonomer serves. In the implementation of components (A), (B) and (C) in addition to the resulting prepolymer remaining vinyl monomer or acrylate / methacrylate monomer thus needs in the production not separated the prepolymer of the invention to become; rather, the reaction mixture can be as it is is, for the preparation of the curable compositions of the invention used and further processed.

According to the type of hardening mechanism desired the curable compositions of the invention is a hardener system added.

When the curing is done by radical polymerization if the hardening system consists of suitable initiators, optionally in conjunction with accelerators.

Suitable initiators are, for example, diacyl peroxides such as Dibenzoyl peroxide and di-p-chlorobenzoyl peroxide or peroxyester such as tert-butyl peroxybenzoate or alkyl peroxides such as Bis (tert-butyl peroxy) butane and dicumyl peroxide or hydroperoxides such as cumene hydroperoxide, tert-butyl hydroperoxide and Methyl ethyl hydroperoxide.

As a polymerization accelerator are optionally aromatic Amines added.  

When curing with light in the ultraviolet and / or visible Area to be carried out, the curable Added mass photoinitiators.

Suitable photoinitiators are, for example, in DE-OS 22 51 048 and 20 03 132 as well as in US-PS 25 48 685, 24 95 987, 35 51 246 and 35 58 387 and in EP-A 00 73 413 described. Some of these known and for the invention Useful photoinitiators are benzophenone and its derivatives, acyloins, such as benzoin and its derivatives, Anthraquinones, aromatic disulfides, vicinal diketones and their derivatives such as benzil, benzilacetates, z. B. benzil dimethyl ketal, Camphorquinone, fluorenone and thioxantone, Multinuclear quinones, acridines and quinoxalines; furthermore trichloromethyl s-triazines, 2-halomethyl-4-styryl-1,3,4-oxadiazole Derivatives, trihalogenmethylsubstituierte Halogenoxazole and the Tricarbonylmethylen- described in DE-OS 33 33 450 Heterocycles.

In addition to the photoinitiators, reducing agents, z. As tertiary amines, to accelerate the curing of Masses are added.

Suitable photoinitiators are also metal carbonyls such as Mo₂ (CO) ₁₀, Fe (CO) ₅, Re₂ (CO) ₁₀, Cr (CO) ₆, Co₂ (CO) ₈, Ni (CO) ₄ and Mo (CO) ₆ and derivatives of these carbonyls.

Preferred photoinitiators are acylphosphine oxide compounds and other phosphorus-containing compounds, such as. B. Dibenzoylisobutylphenylphosphine oxide, dibenzoylisopropylphenyl phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, Bis (2,6-dichlorobenzoyl) -4-n-propylphenyl phosphine oxide and bis (2,6-dichlorobenzoyl) -4-n-butylphenyl phosphine oxide.

When the compositions of the invention by an anaerobic curing mechanism are to be hardened, as a hardener system suitable activators such as cumene hydroperoxide and suitable  Accelerators such as saccharin, methyl-p-toluidine or N, N-dimethylaniline in amounts of 0.01 to 20 wt .-%, preferably from 0.1 to 10% by weight, and in the presence of traces of appropriate Metal ions, e.g. As copper ions added.

The curing of the compositions of the invention is also by Irradiation with actinic radiation, for example electron beams or gamma rays, possible.

The compositions of the invention may also be at least contain a compound that acts as a polymerization inhibitor acts. Polymerization inhibitors prevent premature Gelling the masses and thus increase their shelf life. They are in amounts of 0.001 to 1 wt .-%, preferably from 0.01 to 0.5 wt .-%, based on the weight of Total mixture, added. Suitable inhibitors are, for example Phenols, phenol derivatives, preferably steric hindered phenols in the ortho and / or para position alkylated, for example Toluhydrochinon, 2,6-di- tert-butyl-p-cresol and quinones or hydroquinones such as p-benzoquinone, naphthoquinone and di-tert-butyl-p-benzoquinone.

The curable compositions of the invention can also 0 to 10% by weight of an adhesion improver. When Adhesion improvers are free acrylic and methacrylic acid, Carboxyethyl acrylate, hexaethyl methacrylic phosphate, Silanes such as methacryloxypropyltrimethoxysilane and disilazanes such as divinyl-tetramethyldisilazane.

A preferred curable composition according to the invention contains the following components:

From 20 to 85% by weight of prepolymer,
14.4 to 60% by weight diluent monomer,
0.5 to 10% by weight of adhesion improver,
0.1 to 10% by weight of initiator.

The curable composition of the invention preferably has one Viscosity of 100 mPa · s to 10,000 mPa · s.

The compositions according to the invention can advantageously be used as adhesives, Sealing compounds or investments, particularly advantageous but as a means of joining and bonding bodies or surfaces made of polycarbonate with bodies or surfaces Polycarbonate or other materials. The compositions have excellent adhesion after hardening on different materials like glass, Metal and plastic. Surprisingly high adhesive strengths are used for bonding of various substrates Glass, polymethyl methacrylate (PMMA) and polycarbonates achieved. Also surprising is the surprisingly high stability the cured masses against many chemicals. In contrast, a corrosive behavior of the masses was compared metallic or polymeric substances are not detected. The Adhesions are permanent and show in both thin and also in thick layers in the glue joint a high elasticity of the connecting material, which is why the masses too withstand strong mechanical stresses. The masses own excellent storage stability, and curing times are extremely short. Especially with photoinduced Radical formation becomes an almost lubricant-free Hardening also found in unusually strong layer thicknesses. A polymerization-related shrinkage of the masses is barely noticeable.

Without wishing to be bound by theory, it is believed that the sum of the advantageous properties described the masses according to the invention in the first place the use of a bifunctional polyether derivative the preparation of the prepolymers is based, in whole or in part consists of polytetrahydrofuran units.

The invention will be described below with reference to exemplary embodiments further explained:

Example 1 a) prepolymer

In an anhydrous, nitrogen-purged apparatus in 50 ml of dry methylene chloride, 3.4 g (20 mmol) Submitted hexamethylene diisocyanate. Then be at a temperature of 0 to 5 ° C over a period of 50 57.2 g (10 mmol) of PTHF diamine 5200 (found Base equivalent: 2860) dissolved in a further 50 ml of methylene chloride, added. After stirring for another 90 minutes 0.1 g of dibutyltin dilaurate was added. The resulting Mixture will turn at 0 to 5 ° C within 10 Minutes with 24.5 g (170 mmol) of hydroxypropyl methacrylate (Surplus) offset. The mixture is added overnight Stirred room temperature and in vacuo at 30 ° C solvent-free made. The resulting reaction product consisting from 75% by weight prepolymer and 25% by weight unreacted Hydroxypropylmethacrylat, without further workup used for the preparation of the curable composition.

b) hardenable mass

18.9 g of the reaction product obtained above with 12.6 g of hydroxypropyl methacrylate, 2.63 g of methacryloxy propyltrimethoxysilane, 0.88 g of acrylic acid and 0.35 g Bis- (2,6-dichlorobenzoyl) -4-n-propylphenyl-phosphine oxide a homogeneous liquid adhesive composition mixed. These Mass has a viscosity of 3200 mPa · s (measured with a plate-cone viscometer) and is for the used adhesions described below.

Five pressure shear strength test specimens of the dimensions 20 mm × 20 mm × 5 mm are washed with isopropanol, then with the adhesive mass at room temperature glued and with a standard UV lamp (DELO-Lux 03 of the company DELO Kunststoffchemie GmbH & Co. KG, Munich-  Graefelfing) irradiated for 60 seconds. At these moldings be with a universal tester of the company Zwick (test speed: 10 mm / min) the compressive shear strengths measured, with the following values were:

Glass / glass | 20.4 mPa PMMA / PMMA 17.8 mPa Polycarbonate / Polycarbonate 7.7 mPa

(The specified measured values are those from the individual measurement results average values.)

On each of five tensile test specimens with the dimensions 26 × 6 × 2 mm (shoulder rod measuring section 10 × 2 × 2 mm) become 16.2 mPa tensile strength at 183% elongation at break measured (cohesion crack; 5 mm / min).

example 2 a) prepolymer

In an anhydrous apparatus, 200 g (100 mmol) PTHF 2000 and 0.16 g of dibutyltin dilaurate added. At 35 to 40 ° C over 33 minutes 33.6 g Dropped (200 mmol) of hexamethylene diisocyanate and over Night stirred. This mixture is over at 35 to 40 ° C a period of 25 minutes with 67.3 g (468 mmol) Added hydroxypropyl methacrylate and stirred overnight and again with 46.75 g of hydroxypropyl methacrylate. The resulting reaction product, consisting of 75 Wt% prepolymer and 25 wt% unreacted hydroxypropyl methacrylate) is without further workup to Preparation of the curable composition used.  

b) hardenable mass

15.65 g of the reaction product obtained above with another 6.16 g of hydroxypropyl methacrylate and 0.173 g of bis (2,6-dichlorobenzoyl) -4-n-propylphenylphosphine oxide mixed to a homogeneous adhesive mass.

With this adhesive composition are in Example 1 bonded Druckscherfestigkeitsprüfkörper described, UV cured, and the tensile strengths are below the same Conditions as described in Example 1, measured, whereby the following average measured values resulted:

Glass / glass | 22 mPa PMMA / PMMA 16.7 mPa Polycarbonate / Polycarbonate 10.0 mPa

The tensile test gave a tensile strength of 17 mPa at 150% elongation at break (coherence crack).

Comparative example a) prepolymer

In a dry, nitrogen-purged apparatus 530 g (265 mmol) of polypropylene glycol-2000 (PPG) 2000) and treated with 0.42 g of dibutyltin dilaurate. To this mixture are at 40 to 50 ° C in the course of 60 minutes 89 g (530 mmol) of hexamethylene diisocyanate added, after which overnight at room temperature is left standing. The next day will turn at 40 to 50 ° C for 20 minutes 352.4 g (2.45 mmol) Hydroxypropylmethacrylat added and again over Stirred at room temperature overnight.  

b) hardenable mass

45 g of the PPG diurethane dimethacrylate / hydroxypropyl methacrylate Mixture with 3.75 g of methacryloxypropyltrimethoxysilane, 1.25 g of acrylic acid and 0.5 g of bis (2,6- dichlorobenzoyl) -4-n-propylphenyl-phosphine oxide homogeneous mass mixed. The mass has a viscosity of 3000 mPa · s (plate cone viscometer).

As described in Example 1, with this adhesive composition Pressure shear test body glued, the Mass is cured and the tensile strengths are reduced the same conditions as described in Example 1, determined. This resulted in the following average values:

Glass / glass | 11.8 mPa PMMA / PMMA 13.1 mPa Polycarbonate / Polycarbonate 0.7 mPa

The measured tensile strength was 10.1 mPa at 192% Elongation at break (coherence tear).

As the comparison between the examples of the invention and the comparative example on the other hand, are with the adhesive compositions of the invention, in particular in the Bonding of polycarbonate, surprisingly higher shear strengths achieved as with the conventional adhesive masses, and at comparable high elongation at break.

Claims (17)

1. Prepolymers based on bifunctional polyether derivatives, obtainable by reaction

• (A) a polyether diol or polyether diamine of the formula H-X₁-P-X₁-H (I) wherein X₁ is O, NH or NR and R is an alkyl group having 1 to 4 carbon atoms and the polyether P at least partially composed of polytetrahydrofuran units,
• (B) with a diisocyanate of the formula OCN-A₁-NCO (II) wherein A₁ represents an optionally substituted hydrocarbon radical having 2 to 30 carbon atoms, and
• (C) with a monomeric, hydroxy- and / or amino-functional derivative of acrylic and / or methacrylic acid of the formula wherein
  X₂ is O, NH or NR and R is an alkyl group having 1 to 4 C atoms,
  R¹ is a C₂-C₄-alkylene group and
  R² is H or CH₃,

or by reacting (A) and (D), wherein

• (D) a monomeric, isocyanato-functional derivative of acrylic and / or methacrylic acid of the formula wherein R¹ and R² have the meanings given above, is.

2. Prepolymer according to claim 1, obtainable by reaction the components (A), (B) and (C) in the ratio A: B: C = 1: 2: 2. 3. Prepolymer according to claim 1 or 2, obtainable thereby, that as component (A) a polyether diol or diamine with an average molecular weight of 1000 to 20,000 is used. 4. Prepolymer according to one of claims 1 to 3, characterized available as component (A) is a polyether derivative of Formula (I) is used, wherein P is a polytetrahydrofuran Homopolymer with an average chain length of 4  to 200 [(CH₂) ₄O] units. 5. A prepolymer according to any one of claims 1 to 3, obtainable in that a polyether derivative of the formula (I) is used as component (A), wherein P is a block copolymer having structural elements of the formula is in which
R₃ is an alkylene or isoalkylene radical having in each case 2 to 4 C atoms and
y, z, which may be the same or different, are each an integer from 2 to 100
mean. 6. Prepolymer according to one of claims 1 to 3, characterized available as component (A) is a polyether derivative of Formula (I) is used, wherein P is a copolymer of Tetrahydrofuran and an alkylene oxide with irregular Distribution of [(CH₂) ₄O] - and [R³O] units, wherein R³ has the meanings mentioned in claim 5. 7. Prepolymer according to one of claims 1 to 6, characterized available as component (B) is a diisocyanate of the formula (II) is used, wherein A₁ is an aliphatic, cycloaliphatic or aromatic or a mixed aliphatic cycloaliphatic or a mixed aromatic aliphatic hydrocarbon radical. 8. A curable composition comprising at least one prepolymer according to one of claims 1 to 7, at least one with the Prepolymer copolymerizable diluent monomer, a hardener system and optionally adhesion improvers, polymerization inhibitors and customary auxiliaries and additives.   9. curable composition according to claim 8, characterized the copolymerizable diluent monomer is selected from the group of vinyl monomers and hydroxy-functional Derivatives of acrylic acid and methacrylic acid. 10. A curable composition according to claim 9, characterized the copolymerizable diluent monomer is hydroxyethyl acrylate or hydroxypropyl methacrylate. 11. A curable composition according to any one of claims 8 to 10, characterized characterized in that the hardener system is an initiator for radical polymerization, a photoinitiator or an activator and / or accelerator for the anaerobic Curing includes. 12. Hardenable composition according to one of claims 8 to 11, characterized characterized in that it acts as an adhesion promoter 0 to 10 wt .-% of at least one compound selected is from the group: acrylic acid, methacrylic acid, carboxyethyl acrylate, Hexaethylmethacrylphosphat, silanes, disilazanes. A curable composition according to any one of claims 8 to 12, comprising: 20-85% by weight prepolymer
14.4-60% by weight diluent monomer
0.5-10% by weight of adhesion improver
0.1-10% by weight of initiator. 14. Hardenable composition according to one of claims 8 to 13, characterized by a viscosity of 100 to 10,000 mPa · s. 15. Use of the curable composition according to one of the claims 8 to 14 as an adhesive, sealant or investment material. 16. Use of the curable composition according to one of the claims 8 to 14 as a means for joining and bonding of bodies  or surfaces made of polycarbonate with bodies or surfaces Polycarbonate or other materials.