CA1335389C - Epoxy resins modified with block polymers - Google Patents

Abstract

Compositions comprising (A) an epoxy resin, and (B) a block polymer containing at least one block (B1) of a 1,3-diene-homopolymer or copolymer and at least two blocks (B2) of a lactone homopolymer or copolymer, are especially suitable in conjunction with hardeners for epoxy resins and optionally other additional components for the preparation of adhesives. The cured adhesive bonds are distinguished in particular by high T-peel values.

Description

~ 335389 K-17198/=

Epoxy Resins Modified with Block Polymers The present invention relates to mixtures of epoxy resins and special diene/lactone block polymers, to curable mixtures of this type addition-ally containing hardeners for epoxy resins, to adducts of said block polymers with epoxy resins, to the crosslinked products obtained from said curable mixtures, and to the use of the multicomponent mixtures as adhesives, especially as structural adhesives.

Epoxy resins are distinguished by numerous good properties. Cured products, however, have insufficient flexibility and impact strength for certain applications and their adhesion to oily steel is inadequate.
Although the known flexibilising modifiers do in general effect an enhancement of the flexibility of the cured products, the peel strength is largely unsatisfactory. In addition, the incorporation of such modifiers reduces the lap shear strength and the glass transition temperature.

The use of polycaprolactone and butadiene copolymer flexibilisers is known per se. For example, US patent specification 3 678 131 discloses adhesive compositions of enhanced toughness which contain, as epoxy resin component, a reaction product of a polyepoxide with a smaller amount of a carboxyl group containing polymer, for example a butadiene/acrylonitrile copolymer, and with 2,2-bis(4-hydroxyphenyl)sulfone.

Modified epoxy resin compositions which contain, as flexibiliser, a butadiene/acrylonitrile copolymer or a butadiene/methacrylonitrile copolymer containing COOH, OH or SH end groups are disclosed in US patent specification 3,947,522. The properties of the compositions, which are used for the preparation of adhesives, are enhanced by vulcanising the butadiene copolymer with an organic peroxide or with sulfur.

- 2 - ~ 3 3 ~ 3 ~ 9 Epoxy resins modified with polycaprolactone or with polypropylene oxideare described in the Journal of Polymer Science, Polymer Chemistry Edition, Vol. 12, pp. 689-705 (1974). The mixtures are cured with anhydride hardeners. The use of modifiers with a suitable molecular weight gives two-phase crosslinked systems which display a superior balance of heat distortion temperature and impact strength.

The modification of epoxy resins with reactive polybutadienes is described in Polym. Mater. Sci. Eng., Vol. 49, pp. 383-387 (1983). The miscibility of the epoxy resin with the polybutadiene is increased either by pre-reacting the terminal carboxyl groups of the polybutadiene with the epoxy groups of the resin or by attaching a polyester block to the polybutadiene. The polyester block is formed in situ by reacting the terminal hydroxyl or carboxyl groups of the polybutadiene with phenyl glycidyl ether as diol component and hexahydrophthalic anhydride as acid component. Such end-capped polybutadienes are used as flexibilising modifiers with epoxy resin based on bisphenol A, and the mixture is cured with hexahydrophthalic anhydride or with diethylenetriamine.

Mixtures of epoxy resins and phenol-capped polyurethanes are disclosed in GB patent specification 1,399,257. The polyurethanes are obtained by reacting prepolymeric diisocyanates with unsubstituted or substituted monophenols. The products no longer contain any free phenolic hydroxyl groups. They are combined with epoxy resins and polyamine hardeners to give curable coating compositions which display particular elasticity.

Prior art products based on epoxy resins and butadiene homopolymers or copolymers normally do not contain large amounts of the flexibilising modifier, as compositions containing a large amount of modifier cannot be cured or can only be insufficiently cured, or their viscosities are too high. Polybutadiene oligomers with epoxy reactive groups are not compat-ible with the epoxy resin.

It has now been found that it is possible to cure mixtures of epoxy resins and large amounts of special diene/lactone block polymers and thus to prepare highly flexible products. The diene/lactone block polymers as defined herein are readily dispersible without the addition of further dispersing auxiliaries.
Accordingly, the present invention relates to compositions comprising (A) an epoxy resin, and (B) a block polymer containing at least one block IBl) of a 1,3-diene-homopolymer or -copolymer which contains, in addition to the diene component, 0.1 to 50 mol-% of a vinylaromatic compound, acrylonitrile, methacrylonitrile or of an acrylic acid or methacrylic acid derivative and at least two blocks (B2) of a lactone homopolymer or copolymer which contains, in addition to the lactone component, up to 10% by weight of an alkylene oxide or a diol as co-component, and, if required, (C) a compound of formula I

R X - C -Y - R ~ )m ( ) wherein m is 1 or 2, n is 2 to 6, Rl is the n-valent radical of an elastomeric prepolymer, which is soluble or dispersible in epoxy resins, after removal of the terminal isocyanate, -3a-amino or hydroxyl groups, X and Y each are independently of the other -0- or -NR3-, with the proviso that at least one of these groups is -NR3-, R is an m+1-valent radical of a poly-phenol or aminophenol after removal of the phenolic hydroxyl groups or of the amino group, and R is hydrogen, C1-C6alkyl or phenyl, and, if required, (D) a hardener for epoxy resins, and, if required, (E) an accelerator.
In principle, any of the epoxy resins customarily employed in epoxy resin technology may be used as component (A).
Examples of epoxy resins are:
I) polyglycidyl and poly-(~-methylglycidyl) esters which can be obtained by reacting a compound containing at least two carboxyl groups in the molecule with epichlorohydrin or ~-methylepichlorohydrin. The reaction is conveniently carried out in the presence of a base.
An aliphatic polycarboxylic acid may be used as the compound containing at least two carboxyl groups in the molecule.
Examples of such polycarboxylic acids are oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and dimerised or trimerised linoleic acid.
It is also possible, however, to use cycloaliphatic polycarboxylic acids, for example tetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, hexahydrophthalic acid or 4-methylhexahydrophthalic acid.

-3b-Examples of further aromatic polycarboxylic acids which may be used are phthalic acid, isophthalic acid and terephthalic acid.

II) Polyglycidyl or poly-(~-methylglycidyl) ethers which can be obtained by reaction of a compound containing at least two free alcoholic hydroxyl groups and/or phenolic hydroxyl groups with a suitably substituted epichlorohydrin under alkaline conditions, or in the presence of an acid catalyst, and subsequent treatment with alkali.

Ethers of this type are derived, for example, from acylic alcohols suchas ethylene glycol, diethylene glycol and higher poly(oxyethylene) glycols, 1,2-propanediol or poly(oxypropylene) glycols, 1,3-propanediol, 1,4-butanediol, poly(oxytetramethylene) glycols, 1,5-pentanediol, 1,6-hexanediol, 2,4,6-hexanetriol, glycerol, 1,1,1-trimethylolpropane, pentaerythritol, sorbitol and polyepichlorohydrins.

They are also derived, for example, from cycloaliphatic alcohols such as 1,4-cyclohexanedimethanol, bis(4-hydroxycyclohexyl)-methane or 2,2-bis(4-hydroxycyclohexyl)-propane, or they contain aromatic nuclei such as N,N-bis(2-hydroxyethyl)aniline or p,p'-bis(2-hydroxyethylamino)diphenyl-methane.

The epoxide compounds may also be derived from mononuclear phenols, forexample resorcinol or hydroquinone, or they are based on polynuclear phenols, for example bis(4-hydroxyphenyl)methane, 4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)sulfone, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)-propane, as well as novolaks which can be obtained by condensing aldehydes such as formaldehyde, acetaldehyde, chloral or furfuraldehyde, with phenols such as phenol, or with phenols which are substituted in the nucleus by chlorine atoms or C1-Cgalkyl groups, for example 4-chloro-phenol, 2-methylphenol or 4-tert-butylphenol, or by condensation with bisphenols, as described above.

III) Poly(N-glycidyl) compounds which may be obtained by dehydrochlor-inating the reaction products of epichlorohydrin with amines which contain at least two amino hydrogen atoms. These amines are, for example, aniline, n-butylamine, bis(4-aminophenyl)methane m-xylenediamine or bis(4-methyl-aminophenyl)methane.

_ - 5 ~ 1 3 3 5 3 8 9 The poly-(N-glycidyl) compounds also comprise, however, triglycidyl isocyanurate, N,N'-diglycidyl derivatives of cycloalkyleneureas such as ethyleneurea or 1,3-propyleneurea, and diglycidyl derivatives of hydantoins such as 5,5-dimethylhydantoin.

IV) Poly(S-glycidyl) compounds, for example di-S-glycidyl derivatives derived from dithiols, for example ethane-1,2-dith~l or bis(4-mercapto-methylphenyl) ether.

V) Cycloaliphatic epoxy resins, for example bis(2,3-epoxycyclo-pentyl) ether, 2,3-epoxycyclopentyl glycidyl ether, 1,2-bis(2,3-epoxy-cyclopentyloxy)ethane or 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclo-hexanecarboxylate.

It is also possible, however, to use epoxy resins in which the 1,2-epoxy groups are attached to various heteroatoms or functional groups. These compounds comprise, for example, the N,N,O-triglycidyl derivative of 4-aminophenol, the glycidyl ether/glycidyl ester of salicylic acid, N-glycidyl-N'-(2-glycidyloxypropyl)-5,5-dimethylhydantoin or 2-glycidyl-oxy-1,3-bis(5,5-dimethyl-1-glycidylhydantoin-3-yl)propane.

It is preferred to use epoxy resins having an epoxy content of 2 to 10 equivalents/kg and which are glycidyl ethers, glycidyl esters or N-glycidyl derivatives of aromatic, heterocyclic, cycloaliphatic or aliphatic compounds.

Particularly preferred epoxy resins are polyglycidyl ethers of bis-phenols, for example 2,2-bis(4-hydroxyphenyl)propane or bis(4-hydroxy-phenyl)methane, of novolaks obtained by reacting formaldehyde with a phenol, or of the aliphatic diols mentioned above, especially 1,4-butane-diol.

The most preferred epoxy resins are polyglycidyl ethers based on bis-phenol A.

- 6 ~ 1 335389 The block polymer (B) of the compositions of this invention contains atleast one block (B1) of a 1,3-diene homopolymer or copolymer and at least two blocks (B2) of a lactone homopolymer or copolymer. The block polymer may be of the type B2-Bl-B2, Bl(B2) or -~Bl-B2~-. If the blocks Bl or B2 are copolymers, they are preferably random polymers.

Examples of 1,3-dienes for the preparation of the block (Bl) are butadiene, isoprene and chloroprene. Copolymers based on butadiene are preferred.

In addition to the diene component, the block Bl may contain 0.1 to 50 mol%, preferably 0.1 to 30 mol%, based on the entire block, of one or more ethylenically unsaturated co-components, especially of a vinyl-aromatic compound, acrylonitrile, methacrylonitrile or of an acrylic acid or methacrylic acid derivative.

Examples of suitable ethylenically unsaturated comonomers for the preparation of the block (B1) are acrylic acid, methacrylic acid, esters of acrylic or methacrylic acid, for example the methyl, ethyl or glycidyl esters, amides of acrylic or methacrylic acid, fumaric acid, itaconic acid, maleic acid or the esters or hemiesters thereof, for example the monomethyl or dimethyl esters, or maleic acid, or itaconic anhydride;
vinyl esters, for example vinyl acetate, styrene, substituted styrenes such as styrenes which are chlorinated or brominated in the nucleus, or vinyl toluene, ethylene, propylene, or preferably acrylonitrile or methacrylonitrile.

Preferred co-components of the block (Bl) are styrene, acrylates, methacrylates or, preferably, acrylonitrile. The block (Bl) of the block polymer is preferably a butadiene/acrylonitrile copolymer or, most preferably, a butadiene homopolymer.

The length of the block (Bl) is preferably equivalent to a molecular weight M of 500 to 10 000, more particularly from 1000 to 5000. If the co-component, or one of the co-components, of the block (Bl) contains groups which are reactive with epoxy resins of cyclic lactones, for - _ 7 _ 1 3 3 5 3 8 9 example the carboxyl groups of acrylic acid or methacrylic acid, then the block (B1) preferably contains not more than 10 mol% of said co-component.

Block polymers of the type B2-Bl-B2 re obtained by polymerising cyclic lactones on to end groups of the block (Bl) which are reactive with ryGlic lactones. Block polymers of the type Bl(B2) are obtained by polymerising cyclic lactones on to functional groups of comonomer units of the block Bl, which functional groups are reactive with cyclic lactones.

The block polymer (B) preferably contains not less then 20 % by weight,most preferably 25 to 55 % by weight, of the 1,3-diene, based on the total weight of the blocks (Bl) and (B2).

The blocks (B2) of the block polymer are preferably obtained by homo- or copolymerisation of lactones of formula ~ ~ ~ O or /C= ~ ~ ~ =O

wherein the substituents R are independently of one another hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl or aryl, with the proviso that the total number of carbon atoms of the sustituents R is not greater than 12, and wherein a is 1, 3, 4 or 5.

Alkyl groups R are straight-chain or branched radicals and are, for example, methyl, ethyl n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, 2-ethylbutyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl or n-dodecyl. Preferably R is C1-C6alkyl, especially straight-chain C1-C6alkyl and, most preferably, is methyl.

R as cycloalkyl is, for example, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl or cyclododecyl. The preferred meanings are cyclohexyl and cyclopentyl.

~ -- 8 R as alkenyl is, for example, vinyl, allyl, l-propenyl, l-butenyl, l-pentenyl or l-hexenyl, preferably vinyl or l-propenyl and, most preferably, allyl.

Cycloalkenyl is, for example, cyclohexenyl or cyclopentenyl. The preferred aryl radical is phenyl. R is preferably hydrogen.

Examples of suitable lactones are ~-propiolactone, ~-valerolactone, E-caprolactone and lactones of the following acids: 2-methyl-3-hydroxy-propionic acid, 3-hydroxynonanoic acid or 3-hydroxypelargonic acid, 2-dodecyl-3-hydroxypropionic acid, 2-cyclopentyl-3-hydroxypropionic acid, 3-phenyl-3-hydroxypropionic acid, 2-naphthyl-3-hydroxypropionic acid, 2-n-butyl-3-cyclohexyl-3-hydroxypropionic acid, 2-phenyl-3-hydroxytri-decanoic acid, 2-(2-methylcyclopentyl)-3-hydroxypropionic acid, 2-methyl-phenyl-3-hydroxypropionic acid, 3-benzyl-3-hydroxypropionic acid, 2,2-dimethyl-3-hydroxypropionic acid, 2-methyl-5-hydroxyvaleric acid, 3-cyclohexyl-5-hydroxyvaleric acid, 4-phenyl-5-hydroxyvaleric acid, 2-heptyl-4-cyclopentyl-5-hydroxyvaleric acid, 2-methyl-3-phenyl-5-hydroxyvaleric acid, 3-(2-cyclohexylethyl)-5-hydroxyvaleric acid, 4-benzyl-5-hydroxyvaleric acid, 3-ethyl-5-isopropyl-6-hydroxycaproic acid, 2-cyclopentyl-4-hexyl-6-hydroxycaproic acid, 3-phenyl-6-hydroxy-caproic acid, 3-(3,5-diethylcyclohexyl)-5-ethyl-6-hydroxycaproic acid, 4-phenylpropyl-6-hydroxycaproic acid, 2-benzyl-5-isobutyl-6-hydroxy-caproic acid, 2,2,4-trimethyl-3-hydroxy-4-pentenoic acid, 7-phenyl-6-hydroxy-6-octenoic acid, 2,2-bis(l-cyclohexyl)-5-hydroxy-5-heptenoic acid, 2,2-dipropenyl-5-hydroxy-5-heptenoic acid, 2,2-dimethyl-4-propenyl-3-hydroxy-3,5-heptadienoic acid and the like. Mixtures of two or more of the above lactones may also be used.

The lactone-containing block (B2) may also contain smaller amounts, preferably up to 10 % by weight, of co-components. Examples of suitable co-components are alkylene oxides such as ethylene oxide or propylene oxide, or diols such as hexanediol.

It is especially preferred to use E-caprolactone as lactone component of the block (B2).

g Block polymers containing 1,3-diene homopolymer or copolymer blocks andlactone homopolymer or copolymer blocks are known and can be prepared in known manner.

The blocks (B1) can be prepared, for example, by radical or anionic polymerisation of ethylenically unsaturated compounds using known catalysts. The blocks (B1) contain functional groups such as COOH, OH, SH, NHz, /NH or -¢-M groups, where M is an alkali metal such as Li, which may react further with the lactone monomer to give the block polymer. The functional groups can be introduced by using a suitable functional initiator or by incorporating comonomers which contain functional groups into the polymer chain.

Suitable diene-containing polymers containing functional end groups as well as methods of preparing them are described, for example, in Rubber Chemistry and Technology, Vol. 42, pp. 71-109 (1969).

The diene-containing block (Bl) may also consist of microparticles having a diameter of ca. 0.1-50 ~m, preferably of 0.1-20 ~m, which are prepared, for example, by emulsion polymerisation of dienes with comonomers which contain OH or COOH groups, or by polymerisation of such mixtures of monomers in a lactone such as ~-caprolactone. Suitable methods of preparing emulsion polymers are described, for example, in W.R. Sorensen, T.W. Campbell, Preparative Methods of Polymer Chemistry, Interscience Publishers, John Wiley & Sons, New York 1968, page 313.

Many such suitable diene-containing functional polymers are commercially available, for example HYCAR~ CTB, CTBN or ATBN polymers sold by Goodrich.

The reaction of the diene-containing polymers containing COOH, OH, SH, NH2 or /NH functional groups with a suitable lactone is preferably carried out in a temperature range from ca. 100-250C, more particularly at ca. 180C, for ca. 1 to 10 hours in the presence of a reaction catalyst such as dibutyltin oxide, dibutyltin laurate or titanium tetraisopropylate. The amount of catalyst is preferably 0.01 to 5 ~0 by weight, most preferably 0.1 to 0.5 % by weight, based on the weight of lo - 1 3 3 5 3 8 9 the lactone. The reaction of the diene-containing polymer which contains -¢-M groups such as -¢-Li groups with lactones is preferably carried out in the temperature range from ca. -30 to +150C, most preferably from ca. O to 120C.

Specific methods of preparing the diene/lactone block polymers using oxirane compounds or polyaziridinyl compounds are described by L.H. Hsien et al. in US patent specification 3,585,257, in J. Appl.
Polym. Sci. 22, 1119-1127 (1978), and in US patent specifica-tion 3,880,955. For example, an alkali metal containing diene polymer is reacted first with an oxirane such as ethylene oxide, and the resultant product is then reacted with a lactone such as ~-caprolactone to the corresponding block polymer. In the aforementioned US patent 3,585,257, individual cycloaliphatic diepoxides and individual glycerol tris(epoxy-alkanoates) are also cited as suitable oxirane compounds and used in Examples IX and X. Depending on their composition, the diene/lactone block polymers referred to above have rubber-like, leather-like or thermoplastic properties and display good mechanical properties and ozone resistance.

According to the teaching of German Offenlegungsschrift 3,000,290, similar block polymers are used together with aromatic polycarbonates as impact strength modifiers in thermoplastic polyester compositions. The block polymer is a homopolymer or copolymer of conjugated dienes and/or vinyl aromatic compounds, which block polymer is end-blocked with a rubber-like polyester, for example a styrene/butadiene copolymer which is end-blocked with E-caprolactone.

The block length of the polylactone-containing block (B2) of the eligible block polymers of this invention is preferably equivalent to a molecular weight M of 200 to 10 000, most preferably of 500 to 3000.

The average functionality of the block polymers (B) is not less than 2,preferably from 2 to 6 and, most preferably, from 2 to 3.

The block polymers (B) may also contain glycidyl groups. One possible method of preparing such glycidylated block polymers comprises reacting the block polymers (B) with a glycidyl group containing epoxy resin. In this process, the glycidyl groups of the resin react with the reactive functional groups, for example with carboxyl groups, of the block polymer. If desired, the reaction can also take place in the presence of an advanceme~t agent for epoxy resins, for example of a bisphenol. The reaction suitably takes place in the presence of a catalyst such as triphenylphosphine, a tertiary amine, a quaternary ammonium or phospho-nium salt or chromium acetylacetonate, at elevated temperature, for example at 140C, for ca. 4 to 5 hours. In this reaction it is preferred to use ca. 0.1-5 % by weight, more particularly ca. 1-2 % by weight, of the catalyst, based on the amount of epoxy resin and, if used, the advancement agent.

Another possible method of preparing the glycidylated block polymers comprises reacting the 1,3-diene-containing blocks with a glycidyl group containing epoxy resin in the absence of presence of an advancement agent, for example a bisphenol, and subsequently reacting the adduct obtained with a lactone, for example ~-caprolactone. In this method of preparation, the epoxy groups of the resin react with reactive functional groups, for example carboxyl groups, of the 1,3-diene polymer, and then the secondary hydroxyl groups formed by the addition of the carboxyl groups to the glycidyl groups react with the lactone to give the glycidylated diene/lactone block polymer. The reaction conditions and any catalysts used for the formation of the epoxy resin adducts and for the polymerisation of the lactone conform to the conditions already referred to for carrying out these reactions. The reaction of the epoxy resin adducts with cyclic lactones may also be carried out in situ during the curing if cyclic lactones with transesterification catalysts, for example dibutyltin oxide, are added.

The above described glycidylated adducts are novel and also constitute an object of this invention.

~~ - 12 - 1 335389 Accordingly, the invention relates to glycidylated adducts obtainable by reacting a block polymer (B) which contains at least one block (B1) based on a 1,3-diene homopolymer or copolymer and at least two blocks (B2) of a lactone homopolymer or copolymer with a glycidyl group containing epoxy resin.

The invention further relates to glycidylated reaction products obtainable by reacting a lactone with an adduct of a 1,3-diene homo-polymer or copolymer with a glycidyl group containing epoxy resin.

In addition to components (A) and (B), the composition of this invention may further comprise (C) a compound of formula I

Rl X--C--Y--R2--~OH) (I), -n wherein m is 1 or 2, n is 2 to 6, R1 is the n-valent radical of an elastomeric prepolymer, which is soluble or dispersible in epoxy resins, after removal of the terminal isocyanate, amino or hydroxyl groups, X
and Y are each independently of the other -O- or -NR3-, with the proviso that at least one of these groups is -NR3-, R2 is an m + l-valent radical of a polyphenol or aminophenol after removal of the phenolic hydroxyl groups or of the amino group, and R3 is hydrogen, C1-C6alkyl or phenyl.

Component (C) is a selected polyurethane or a selected polyurea derivedfrom a specific prepolymer. The term "elastomeric prepolymer radical R1"
will be understood as meaning within the context of this description the radical of a prepolymer which, after capping the n-isocyanate, n-amino or n-hydroxyl end groups of said radical, results in a compound of formula I
which, in conjunction with the epoxy resin (A) and the block polymer (B) produces, after curing, an elastomer phase or a mixture of elastomer phases. These elastomer phases may be homogeneous or heterogeneous combinations of components (A), (B) and (C). The elastomer phase or phases usually have a glass transition temperature below 0C.

The expression "prepolymer which is soluble or dispersible in epoxy resins" will be understood as meaning within the context of this description the radical of a prepolymer which, after capping the n iso-cyanate, n amino or n hydroxyl end groups of said radical, results in a compound of formula I which is soluble or dispersible in an epoxy resin (A) or in a combination of an epoxy resin (A) and a block polymer (B), without the addition of further auxiliaries, such as emulsifiers. Hence a homogeneous phase forms, or at least no macroscopic phase separation of one of components (A), (B) or (C) or of a mixture of said components takes place.

The solubility or dispersibility of (C) in the combination of (A) and (B) is effected primarily by the choice of suitable prepolymer radicals R1.
Examples of suitable radicals are cited hereinafter in the description of the preparation of component (C).

The compound of formula I is preferably a water-insoluble compound, by which is meant in the context of this description a compound whose solubility in water is less than 5 % by weight, preferably less than 0.5 % by weight, and which, when stored in water, absorbs only a small amount of water, preferably less than 5 % by weight, most preferably less than 0.5 % by weight, or which, in the course thereof, exhibits only slight swelling.

The prepolymers on which R1 is based usually have molecular weights (number average) of 150 to 10 000, preferably 1 800 to 3 000.

The average functionality of these prepolymers is at least two, prefera-bly 2 to 3 and, most preferably, 2 to 2.5.

The term "elastomeric polyurethane" or "elastomeric polyurea" is known per se to those skilled in the art (cf. C. Hepburn: "Polyurethane Elastomers", Applied Science Publishers, London 1982).

In general, elastomeric polyurethanes or polyureas contain rigid and flexible components (hard and soft segments).

Component (C) may be a liquid or thermoplastic phenol-terminated poly-urethane or polyurea of formula I. Compounds having a softening point below 80C, preferably below 40C, are preferred.

_ - 14 ~ 1 3 3 5 3 & 9 Component (C) may also be used as an adduct of a phenol-terminated polyurethane or polyurea of formula I with an epoxy resin. Adducts of this type can be prepared in the manner described above.

For highly flexible systems, adducts of such polyurethanes or polyureascontaining glyc-idyl ethers of aliphatic diols, such as 1,4-butanediol or 1,6-hexanediol, are preferred.

Suitable components (C) can be linear or are branched types. The degreeof crosslinking is chosen such that the polymer does not form a macro-scopic gel. This condition will generally be met if component (C) is soluble or at least dispersible in a polar organic solvent or in an epoxy resin.

The compounds of formula I in which X is -NR3- and Y is -NR3- or, preferably, -O-, may be prepared by various routes, depending on the nature of the prepolymer on which R1 is based.

Prepolymer isocyanates can be prepared by reacting compounds of formula IIIa with polyphenols or aminophenols of formula IVa (process a) Rl ~NCO ) ( I I I a), H--Y--R2 ~0H ) ( IVa);

polyureas of formula I, wherein X is -NR3- and Y is -NR3-, may also be prepared by reacting prepolymeric amines of formula IIIb with urethanes of formula IVb (process b) R1-~NR3H) (IIIb), R11-O- 8 NR3-R2 ~OH) (IVb).

Compounds of formula I, wherein X is -NR3- and Y is -NR3- or -O-, and which have ortho-phenols or peri-phenols or ortho-aminophenols or peri-aminophenols as end groups, can also be prepared by reacting compounds of formula IIIb with cyclic carbonates or urethanes of formula IVc (process c) ~ - 15 - l 3 3 5 3 8 9 Rl-~NR3H) (IIIb), O=C ~ 12 (IVc) In the formulae IIIa, IIIb, IVa, IVb and IVc above, the substituents R1, R2, R3 and Y and also the indices m and n are as defined previously, R
is a radical which acts as a leaving group, for example alkyl or aryl, preferably C1-C6alkyl or phenyl, a~d R12 is a divalent, carbocyclic-aromatic radical which has one of the meanings given for R2 and at which each of the groups -O- and -Y- are in the ortho- or peri-position relative to one another.

The compounds of formula I, wherein X is -O- and Y is -NR3-, may be obtained by methods analogous to those described in European patent application 247,467.

For example, an elastomeric and hydroxyl-terminated prepolymer of formula V, which is soluble or dispersible in epoxy resins, is reacted with an amount equivalent to the OH content of the prepolymer, of a carbamate of the formula IVb as defined above R1-~OH) (V), Rl1-O-C-NR3-R2-~OH) (IVb).
n m In these formulae, the substituents R1, R2, R3 and R11 and also the indices m and n are as defined above.

In another embodiment, the prepolymer of formula V may be reacted firstwith an amount of phosgene equivalent to the OH content, and the resultant chlorocarbonyloxy derivative can then be reacted with a phenol or aminophenol of formula IVa.

The radical R2 is normally derived from phenols or aminophenols con-taining a mononuclear or polynuclear, carbocyclic-aromatic radical.

Phenol or aminophenol radicals containing several carbocyclic-aromatic radicals can be condensed or, preferably, attached through bridge members.

Examples of phenols or aminophenols which contain condensed radicals are dihydroxynaphthalenes or dihydroxyanthracenes or aminonaphthols.

Preferred radicals R2 are derived from bisphenols of formula VI
HO OH
(VI), (~R4) (Rs) P q wherein Z is a direct C-C bond or a bridge member selected from the group consisting of -CR6R7-, -O-, -S-, -SOz-, -CO-, -COO-, -CONR8- and -SiR9R10-, R4 and Rs are each independently of the other C1-C2calkyl~
Cz-C6alkenyl, Cz-C6alkynyl or halogen, p and q are each independently of the other O, 1 or 2, R6, R7 and R3 are each independently of the other hydrogen, -CF3 or C1-C6alkyl, or R6 and R7, together with the carbon atom to which they are attached, form a cycloaliphatic radical having 5-12 ring carbon atoms, and R9 and R1~ are C1-C6alkyl.

Particularly preferred radicals R2 are derived from bisphenols of formula VI, wherein the hydroxyl groups are in the 4,4'-position, epsecially the derivatives in which p and q are 1 and R4 and Rs are allyl.

Other particularly preferred radicals R2 are derived from bisphenols offormula VI, wherein Z is selected from the group consisting of -CHz-, -C(CF3)2-, -O-, -SO2-, a direct C-C bond and, especially, -C(CH3)z-, p and q are each O or 1 and R4 and Rs are C~-C6alkyl, Cz-C6alkenyl, particularly allyl, or Cz-C6alkynyl, preferably propargyl.

Further preferred radicals R2 are derived from mononuclear aminophenols, for example 2-, 3- or 4-aminophenol, or from mononuclear polyphenols, for example resorcinol, hydroquinone or pyrogallol.

Patricularly preferred radicals R2 are derived from bisphenols. Examples of bisphenols are 4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)methane, 2,2-bis(4-- 17 - l 3 3 5 3 8 9 hydroxyphenyl)propane and the corresponding 3,3'-dimethyl, 3,3'-dinonyl, 3,3'-diallyl, 3,3'-dichloro, 3,3'-dibromo and 3,3',5,5'-tetrabromo derivatives of these compounds.

R4 or Rs as C1-Czoalkyl are linear or branched radicals. Examples of these radicals are: methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, n-hexyl, 2-ethylbutyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl or n-eicosyl. R4 and Rs are preferably C1-C6-alkyl, more particularly linear C1-C6alkyl and, most preferably, methyl.

Radicals defined as C1-C6alkyl are preferably linear radicals, i.e.
methyl, ethyl, n-propyl, n-butyl, n-pentyl or n-hexyl, most preferably methyl.

R4 and Rs as C2-C6alkenyl are typically vinyl, allyl, 1-propenyl, 1-butenyl, 1-pentenyl or 1-hexenyl. Vinyl, 1-propenyl and allyl are preferred, and allyl is most preferred.

R4 and Rs as C2-C6alkynyl are typically ethynyl, propargyl, 1-butynyl, 1-pentynyl or 1-hexynyl. Propargyl is preferred.

R4 and Rs as halogen may be fluoro, chloro, bromo or iodo. Chloro or bromo is preferred, and bromo is most preferred.

Compounds of formula VI containing alkyl or alkenyl substituents are preferably used if the composition of this invention is to have high adhesion to oily steel.

Halogen-containing compounds of the formula VI generally increase the flame resistance.

A cycloaliphatic radical CRsR7 is, for example, a cyclopentylidene, cyclohexylidene, cycloheptylidene, cyclooctylidene or cyclododecylidene radical. Cyclohexylidene and cyclododecylidene are preferred.

R3 is preferably hydrogen.

The isocyanate of the formula IIIa is either a prepolymer al) which is derived from the addition of a polyisocyanate, preferably a diisocyanate or triisocyanate and, most preferably, a diisocyanate, to a prepolymer polyhydroxyl or polysulfhydryl component or to a mixture of such pre-polymer components, if appropriate in combination with chain extenders (short-chain polyhydroxyl, polysulfhydryl or polyamine compounds) or a prepolymer polyisocyanate a2) which is derived from a prepolymer poly-amine of the formula IIIb, especially from a prepolymer polyetheramine.

Prepolymer components for the preparation of al) may be condensation oraddition polymers on to which in some cases 1-olefins may be grafted, which 1-olefins also contain polar groups, for example nitrile, ester or amide groups, in addition to non-polar groups. Examples of such polymers are polyesters, polyethers, polythioethers, polyacetals, polyamides, polyester-amides, polyurethanes, polyureas, alkyd resins, polycarbonates or polysiloxanes, provided these compounds are hydroxyl-terminated or sulfhydryl-terminated, result in compounds of formula I which are soluble or dispersible in epoxy resins, and impart elastomeric properties to these resins in accordance with the above definition.

Polyethers or segmented prepolymers containing polyether segments, suchas polyether amides, polyether urethanes and polyether ureas, are preferred.

These compounds are known to those skilled in the art in the field of polyurethane chemistry as components for the preparation of poly-urethanes. They can be linear or branched; linear types are preferred.

Preferred components for prepolymers al) are hydroxyl-terminated pre-polymers having average molecular weights (number average) of 150-10 000, most preferably 500-3 000.

In addition to the hydroxyl-terminated or sulhydryl-terminated pre-polymers, chain extenders may also be used for the preparation of the prepolymer polyisocyanates al).

Such monomers are preferably difunctional or trifunctional.

If trifunctional or polyfunctional hydroxyl-terminated or sulfhydryl-terminated prepolymers or trifunctional or polyfunctional chain extenders are used for the preparation of component al), these components should be chosen such that an adduct al) which is soluble or at least swellable in organic solvents is formed.

When using polyfunctional components, the degree of crosslinking can beregulated in a manner known per se by the nature and ratios of said components. It is also possible to vary the elastomer properties in a manner known per se by means of the degree of crosslinking.

Thus when using difunctional prepolymers or trifunctional or poly-functional chain extenders, normally only a small proportion of the polyfunctional component will be used. But if a combination of di-functional and trifunctional or polyfunctional prepolymers is used, then usually a larger amount of the polyfunctional chain extender can be present without excessive crosslinking taking place. The degree of crosslinking will also depend on the functionality of the polyisocyanate.
Thus if trifunctional or polyfunctional, hydroxyl-terminated or sulf-hydryl-terminated components are present, diisocyanates will normally be used; but if difunctional, hydroxyl-terminated or sulfhydryl-terminated components are used, then polyfunctional isocyanates will also be used.
Examples of prepolymer components for the preparation of polyiso-cyantes al) are hydroxyl-terminated polyethers, in particular polyethers which lead to water-insoluble compounds of the formula I.

These polyethers comprise, for example, the polyalkylene ether polyols which are obtained by anionic polymerisation, copolymerisation or block copolymerisation of alkylene oxides such as ethylene oxide, propylene oxide or butylene oxide, with difunctional or polyfunctional alcohols such as 1,4-butanediol, l,l,l-trimethylolethane, l,l,l-trimethylol-propane, 1,2,6-hexanetriol, glycerol, pentaerythritol or sorbitol, or with amines such as methylamine, ethylenediamine or 1,6-hexylenediamine, as initiator components, or by cationic polymerisation or copolymerisa-tion of cyclic ethers such as tetrahydrofuran, ethylene oxide or ~ ~ - 20 - l 3353~9 propylene oxide, using acid catalysts such as BF3.etherate or by poly-condensation of glycols which are able to undergo polycondensation with the elimination of water, for example 1,6-hexanediol, in the presence of acid etherification catalysts such as p-toluenesulfonic acid. It is also possible to use oxalkylation products of phosphoric acid or phosphorous acid with ethylene oxide, propylene oxide, butylene oxide or styrene oxide.

Other preferred hydroxyl-terminated polyethers are those on to which 1-olefins, such as acrylonitrile, styrene or acrylic acid esters, have been grafted. In this case the proportion by weight of the graft component is generally 10-50 ~/0, particularly 10-30 %, relative to the amount of polyether employed.

Other examples of prepolymer components for the preparation of polyiso-cyanates al) are hydroxyl-terminated polyester-polyols derived from dicarboxylic and/or polycarboxylic acids and diols and/or polyols, preferably from dicarboxylic acid and diols.

Examples of such polycondensates are the hydroxyl-terminated polyesters which can be obtained by polycondensation of adipic acid, sebacic acid, azelaic acid, dimeric and timeric fatty acids, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid and endomethylenetetrahydrophthalic acid with propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene, triethylene and tetraethylene glycol, dipropylene, tripropylene and tetrapropylene glycol, dibutylene, tributylene and tetrabutylene glycol, 2,2-dimethylpropane-1,3-diol, 1,1,1-trimethylolpropane, 1,1,1-trimethylolethane and 1,2,6-hexanetriol.

Other suitable prepolymer components for the preparation of polyiso-cyanates al) are hydroxyl-terminated polybutadienes, which are reacted especially with hydroxyl-terminated polyethers to form component al).

Further examples of suitable prepolymer components for the prepartion of polyisocyanates al) are polymerisation products of lactones, for example E-caprolactones; or polyalkylene thioether polyols, for example the ~ - 21 - 1 335389 polycondensation products of thiodiglycol with itself and with diols and/or polyols, for example 1,6-hexanediol, triethylene glycol, 2,2-di-methyl-1,3-propanediol or 1,1,1-trimethylolpropane.

The preferred prepolymer components for the preparation of polyiso-cyanates al) are hydroxyl-terminated polyethers or polyesters.

Yet further preferred prepolymer components for the preparation of polyisocyanates al) are mixtures of hydroxyl-terminated polybutadiene and hydroxyl-terminated polyalkylene glycol or hydroxyl-terminated poly-alkylene glycols on to which 1-olefins have been grafted, in particular styrene or acrylic acid derivatives such as acrylic acid esters or acrylonitrile.

~specially preferred prepolymer components for the preparation of polyisocyanates al) are hydroxyl-terminated polyethers, in particular dihydroxyl-terminated polyalkylene glycols.

Chain extenders for the preparation of the prepolymer polyisocyanate al) are known per se. Examples of these chain extenders are the diols and polyols mentioned above for the preparation of the hydroxyl-terminated polyethers, in particular the diols and triols such as 1,4-butanediol, 1,1,1-trimethylolpropane or hydroquinone 2-hydroxyethyl ether, or diamines such as diaminoethane, 1,6-diaminohexane, piperazine, 2,5-di-methylpiperazine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 4,4'-diaminocyclohexylmethane, 1,4-diaminocyclohexane and 1,2-propylene-diamine, or hydrazine, amino acid hydrazides, hydrazides of semi-carbazidocarboxylic acids, bishydrazides and bissemicarbazides.

The preferred chain extenders are short-chain diols or triols.

The prepolymer polyisocyanate a2) can be obtained in a manner known perse from amino-terminated prepolymers of formula IIIb, preferably from amino-terminated polyethers, by reaction with phosgene or with polyiso-cyanates, preferably diisocyanates or triisocyanates and, most prefera-bly, diisocyanates. In addition to containing the amino groups, the amino-terminated prepolymers generally do not contain any further - - 22 ~ 1 335389 radicals having active hydrogen atoms. Prepolymers having terminal amino groups are derived in general from the hydroxyl-terminated condensation or addition polymers described above as components for al), particularly from polyethers.

They can be obtained by reacting said condensation or addition polymerscontaining secondary hydroxyl groups with ammonia,:~r by reacting said condensation or addition polymers containing primary hydroxyl groups, for example polybutylene glycol, with acrylonitrile, and subsequently hydrogenating these products.

Prepolymeric amino-terminated poly-THF can also be obtained by the method of S. Smith et al. in Macromol. Sci. Chem., A7(7), 1399-1413 (1973), by terminating a difunctional, still active cationic THF polymer with potassium cyanate.

The polyisocyanates used for the preparation of components al) or a2) are normally aliphatic, cycloaliphatic, aromatic or araliphatic diiso-cyanates, triisocyanates or tetraisocyanates, or precursors which can be converted into such isocyanates.

Preferred polyisocyanates are the aliphatic, cycloaliphatic or araliphatic diisocyanates or triisocyanates, the aliphatic or cyclo-aliphatic diisocyanates being especially preferred.

The preferred aliphatic diisocyanates are usually linear or branched ~,~-diisoscyanates. The alkylene chains may be interrupted by oxygen or sulfur atoms and may or may not contain ethylenically unsaturated bonds.

~,~-Diisocyanates having linear, saturated Cz-C2~alkylene radicals are preferred.

Examples of such radicals are ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, deca-methylene, dodecamethylene, tetradecamethylene, hexadecamethylene, octadecamethylene and eicosamethylene.

_ - 23 ~ 1 335389 Examples of preferred aliphatic ~ diisocyante radicals which are interrupted by hetero atoms are -(CH2-CH2-O)o CH2-CHz-, -(CH(CH3)-CHz-O) - CH(CH3)-CH2-, -(CH2-CHz-CH2-CH2-O)o CHz-CH2-CH2-CH2-and -(CH2-CH2-S) - CHz-CH2-, wherein o is 1 to 20.

The preferred cycloaliphatic diisocyantes are usually derivatives whichare derived from substituted or unsubsti~uted cyclopentanes, cyclohexanes or cycloheptanes. Two such rings may also be attached to one another through a bridge member.

Examples of such radicals are 1,3-cyclohexylene, 1,4-cyclohexylene or dodecahydrodiphenylmethane-4,4'-diyl.

It is also possible to use diisocyanates or triisocyanates derived fromdimeric or trimeric fatty acids. These compounds can be obtained in a manner known per se from the fatty acids by rearrangement to give the corresponding diisocyanates or triisocyanates (Hoffmann, Curtius or Lossen rearrangements).

Examples of preferred aromatic diisocyanates correspond to the examplesof divalent phenol radicals cited above, in which the -OH groups are replaced by -NCO groups.

Examples of araliphatic diisocyanate radicals are 1,2-xylylene and 1,4-xylylene.

Specific examples of suitable polyisocyanates are 2,4-diisocyanatotoluene and technical mixtures thereof with 2,6-diisocyanatotoluene, 2,6-diiso-cyanatotoluene, 1,5-diisocyanatonaphthalene, 4,4'-diisocyanatodiphenyl-methane and technical mixtures of various diisocyanatodiphenylmethanes (for example the 4,4'- and 2,4'-isomers), urethanised 4,4'diisocyanatodi-phenylmethane, carbodiimidised 4,4'-diisocyanatodiphenylmethane, the uretdione of 2,4-diisocyanatotoluene, triisocyanatotriphenylmethane, the adduct formed from diisocyanatotoluene and trimethylolpropane, the trimer formed from diisocyanatotoluene, diisocyanato-m-xylylene, N,N'-bis-(4-methyl-3-isocyanatophenyl)urea, mixed trimerisation products of diiso-cyanatotoluene and 1,6-diisocyanatohexamethylene, 1,6-diisocyanatohexane, ~ - 24 - ~ 335389 3,5,5-trimethyl-1-isocyano-3-isocyanatomethylcyclohexane (isophorene diisocyanate), N,N',N"'-tris-(6-isocyanatohexyl)biuret, 2,2,4-tri-methyl-1,6-diisocyanatohexane, 1-methyl-2,4-diisocyanatocyclohexane, dimeryl, diisocyanate, 4,4'-diisocyanatodicyclohexylmethane, trimeric isophorone diisocyanate, trimeric hexane diisocyanate and methyl 2,6-diisocyanatohexanoate.

The preparation of component al) or a2) is effected in a manner known per se by reacting the hydroxyl-terminated, sulfhydryl-terminated or amino-terminated elastomeric prepolymer component with a polyisocyanate or with a mixture of these components The reactions may be carried out in the presence or absence of a chain extender.

The preparation of the component al) or a2) is carried out without a solvent or in solvents which are inert to isocyanates.

Examples of inert solvents are esters such as ethyl acetate, butyl acetate, methyl glycol acetate and ethyl glycol acetate; ketones such as methyl ethyl ketone or methyl isobutyl ketone; aromatic compounds such as toluene or xylene, or halogenated hydrocarbons such as trichloroethane or dichloromethane.

If a certain additional chain extending reaction via urethane or urea groups is tolerated or is even desired, then the prepolymers containing hydroxyl, sulfhydryl or amino groups and the monomers which may be present are reacted with the diisocyanate or polyisocyanate in an NCO/OH, NCO/SH or NCO/NHz ratio of 1.5-2.5, preferably 1.8-2.2, first at 0-25C
and with cooling, and subsequently for several hours by heating to preferably 50-120C.

If a chain extending reaction is not desired, then normally a sub-stantially larger excess of diisocyanate or polyisocyanate, for example an NCO/OH, NCO/SH or NCO/NHz ratio of 3-5, and no chain extender, will be used, and the procedure is otherwise as described for low NCO/OH, NCO/SH
or NCO/NHz ratios. After the reaction, any excess diisocyanate or polyisocyanate is removed, for example by thin film distillation or by solvent extraction.

~ - 25 - 1 335389 The reaction of the hydroxyl-terminated, sulfhydryl-terminated or amino-terminated prepolymers with polyisocyanates is carried out in the presence of catalysts which are known per se.

Examples of these catalysts are diazabicyclooctane, dibutyltin dilaurate or tin(II) octoate. These catalysts are added in the customary amounts, for example in amounts of 0.001-2 % by weight, based on the amount of polyisocyanate.

The reaction of components al) or a2) (polyisocyanate IIIa) with the phenol or aminophenol IVa is carried out in similar manner to the above-described reaction of the hydroxyl-terminated, sulfhydryl-terminated or amino-terminated component with the polyisocyanate.

The amount of polyphenol or aminophenol IVa used in this reaction is preferably such that the free NCO groups are substantially consumed by the reaction and that mainly one -OH or -NHz group reacts per polyphenol or aminophenol.

This condition will generally be met if about 2 or 3 mol of OH groups of the bisphenol or trisphenol or about 1 mol of NHz groups of the amino-phenol are supplied per 1 mol of free isocyanate groups.

In the case of the polyphenols IVa, the OH:NCO ratio is generally 1.5:1.0 to 3.0:1.0, preferably 1.8:1.0 to 2.5:1Ø

In the case of the aminophenols IVa, the NHz:NCO ratio is generally 0.8:1.0 to 1.2:1.0, preferably 0.8:1.0 to 1.0:1Ø

It is, of course, also possible to use excess amounts of component IVa,in which case chain lengthening can take place via the phenol; however, the end product should not contain more than 50 % by weight, preferably less than 10 % by weight, of unreacted component IVa, based on the total mixture.

~ - 26 - 1 3 3 ~ 3 8 9 In the case of the aminophenols IVa, a stoichiometric amount is generally desirable.

It is also possible to employ mixtures of phenol and/or aminophenol IVafor capping the polyisocyanate IIIa. These mixtures can also contain small proportions of monophenols. In this process variant, the proportion of monophenol is chosen such that the reaction ~roduct consists mainly of compounds of formula I which contain free phenolic OH groups.

The amino-terminated prepolymers IIIb in process b) or c) will normallybe the prepolymer polyamines which have already been described in process a) and which were used in that process for the preparation of the prepolymer polyisocyanate components IIIa. Preferred compounds IIIb are amino-terminated polethers as defined above.

The urethanes IVb are derived from aminophenols HR3N-R2-(oH) , wherein R2, R3 and m are as defined above. Urethanes IVb are prepared by capping these aminophenols with Rl1-O-CO-Cl in a manner known per se. In this formula, Rll is as defined previously. The reaction of components IIIb and IVb (process b) is generally carried out by adding the two components in stoichiometric proportion or using a small excess of component IVb and by heating the mixture such that virtually all the free amino groups of IIIb are capped.

The reaction is preferably carried out in an inert solvent. Examples ofthese solvents have been listed above.

The cyclic carbonates or urethanes IVc are derived from ortho- or peri-bisphenols or ortho- or peri-aminophenols of formula HO-Rl2-OH or HR3N-Rl2-oH, respectively. In these formulae R3 and Rl2 are as previously defined. The compounds IVc can be obtained therefrom by reaction with phosgene. The reaction of components IIIb and IVc (process c) is generally carried out by adding the two components in stoichiometric proportion or using a small excess of component IVc. In other respects the reaction is carried out as described in process a).

The molecular weight M of the polyurethanes or polyureas (C) is usually within the range from 500 to 50 000, preferably within the range from 500 to 10 000 and, most preferably, within the range from 500 to 3 000.

The viscosity of these compounds is normally less than 150 000 mPa-s, preferably less than 100 000 mPa-s (measured at 80C in an ~pprecht viscosimeter).

The structures of the phenol-terminated polyurethanes or polyureas of formula I which are derived from the reaction according to process a), b) or c) differ, depending on the functionality of the prepolymer radical Rl .

In process a) this functionality is determined, for example, by the functionality of the hydroxyl-terminated, sulfhydryl-terminated or amino-terminated prepolymers, by the chain extenders which may be used, by the functionality of the isocyanate used for the preparation of IIIa, and by the ratios of the individual reactants. Preferred components (C) are compounds of formula I in which X is -NH- and Y is -NH- and, most preferably, -O-.

Components (C) which are also preferred are compounds of formula I which are substantially free from isocyanate groups and contain at least two free phenolic hydroxyl groups and can be obtained by reacting a) a prepolymer polyisocyanate which is al) an adduct of a polyisocyanate with a prepolymer polyhydroxy or polysulfhydryl compound or with a mixture of such compounds, without or in conjunction with a chain extender, or a2) is derived from a prepolymer polyether-amine, with b) at least one phenol containing two or three phenolic hydroxyl groups or an aminophenol containing one or two phenolic hydroxyl groups.

~specially preferred compounds of formula I are derived from prepolymer polyisocyanates a) which have an average isocyanate functionality of 2 to 3.

Compounds of formula I which are particularly preferred are those in which component al) is an adduct of a polyisocyanate with a hydroxyl-terminated prepolymer having an average molecular weight M of 150 to 10 000. The most preferred compounds of formula I are those in which the component for the preparation of component al) is a hydroxyl-terminated polyether or polyester.

This component for the preparation of component al) is preferably used in conjunction with chain extenders.

Especially preferred compounds of formula I are those in which the polyisocyanate for the preparation of component al) is an aliphatic, cycloaliphatic, aromatic or araliphatic diisocyanate or triisocyanate.

In a preferred embodiment of the invention, the preparation of compo-nent al) is carried out using a hydroxyl-terminated polyether or poly-ester, in the absence of a chain extender and using an amount of polyiso-cyanate equivalent to the OH content or an excess thereof, to give, after capping with the polyphenol or aminophenol, polyurethanes of formula VII

[~(HO--~--R2-X-C-NH ~ Rl3-NH-8-o ~ R14 (VII), wherein R2, m and n are as defined above, r is an integer from 1 to 3, X
is -O- or -NH-, Rl3 is the r + l-valent radical of an aliphatic, cyclo-aliphatic, aromatic or araliphatic polyisocyanate after removal of the isocyanate groups, and Rl4 is an n-valent, hydroxyl-terminated polyester or polyether radical after removal of the terminal OH groups, with the proviso that the index m and the radicals R2 and Rl3 may be different within a given molecule.

Compositions containing compounds of the formula VII as component (C) are preferred.

The index m is preferably 1. The index n is preferably 2 or 3, most preferably 2. The index r is preferably 1. Preferred components (C) are compounds of formula VII in which m is 1, n is 2 or 3, r is 1, X is -O-, Rl3 is derived from an aliphatic, cycloaliphatic or aromatic diisocyanate -and R1 4 is a divalent or trivalent radical of a hydroxyl-terminated polyester or polyether having a molecular weight M of 150 to 10 000 after removal of the terminal hydroxyl groups.

Especially preferred components (C) are compounds of formula VII, wherein m is 1, n is 2 or 3, r is 1, X is -0-, R13 is derived from an aliphatic or cycloal;phatic diisocyanate and R1 4 is a divalent or trivalent radical of a polyalkylene ether polyol having a molecular weight M of 150 to 3 000 after removal of the terminal hydroxyl groups.

The particularly preferred components (C) of this last-defined type comprise those in which n is 2 and R14 is a structural unit of formula VIII
-(C H2s-0-)X CsH2s (VIII) in which s is 3 or 4, x is an integer from 5 to 40 and the units -C -H2 ~~ may differ within a given structural unit of formula VIII, within the scope of the given definitions.

Examples of structural units of formula VIII are:
-(CHz-CH(CH3)-O) -CH2CH(CH3)-, -(CH2-CH2-CH2-CH20)x-CHzCH2CH2-CHz- and copolymers containing these structural units.

Preferred components (C) of this invention also comprise compounds which are obtainable by reacting al) an adduct of a substantially equivalent amount of a diisocyanate with a mixture of a dihydroxyl-terminated or trihydroxyl-terminated polyether or polyester and less than 1 mol ~0, based on the hydroxyl-terminated prepolymer, of a diol or triol, preferably of a short-chain diol or triol, and b) an amount of a bisphenol or trisphenol which is substantially equiva-lent to the NC0 content.

In another preferred embodiment of the invention, the preparation of component a2) is carried out using an amino-terminated polyalkylene ether, reacting said ether, in the absence of a chain extender, with an amount of diisocyanate which is equivalent to the NH2 content or with an - _ 30 - 1 335389 excess thereof, or with phosgene, and capping the resultant polyiso-cyanate with a polyphenol or aminophenol IIIa, to give a compound of formula IX

(Ho-~-R3-Y-~-C-NH-R1s ~ ~-NH R1 6 (IX), m -n wherein R3, Y, m and n are as defined above, t is 0 or 1, R~ is the divalent radical of an aliphatic, cycloaliphatic, aromatic or araliphatic diisocyanate after removal of the isocyanate groups, and R16 is the n-valent radical of an amino-terminated polyalkylene ether after removal of the terminal NH2 groups.

Compositions containing compounds of formula IX as component (C) are preferred.

Particularly preferred compositions contain, as component (C), compounds of formula IX, wherein m is 1, n is 2 or 3, Y is -0-, R1s is derived from an aliphatic, cycloaliphatic or aromatic diisocyanate and R1 6 is a divalent or trivalent radical of an amino-terminated polyalkylene ether having a molecular weight M of 150 to 10 000 after removal of the terminal amino groups.

More especially preferred compositions contain, as component (C), compounds of formula IX in which m is 1, n is 2, t is 0, Y is -0- and R16 is derived from a divalent, amino-terminated polyalkylene ether having a molecular weight M of 150 to 6 000.

Most especially preferred compositions contain, as component (C), compounds of formula IX in which m and t are 1, n is 2, R1s is the divalent radical of an aliphatic or cycloaliphatic diisocyanate after removal of the isocyanate groups, and R1 6 is derived from a divalent, amino-terminated polyalkylene ether having a molecular weight M of 150 to 6 000.

The especially preferred components (C) of these two last-defined types comprise those in which R1s is a structural unit of formulae X, XI, XII
or XIII

~ - 31 - 1 335389 -8H-CHz ( O-CHz-CIH-~- (X), Z1 [ ( CIH-CH2-O-~-CH2-ICH ~ (XI), CH3 Y CH3 y in which y is 2 to 70, Z1 is a group -NH-CO-NH or _o-R17-o-, z2 is a group _o-~l 8 _o_, Rl 7 iS a radical of an aliphatic diol after the removal of the two OH groups, and R18 is a radical of an aliphatic triol after removal of the three OH groups.

The preparation of the compositions of the invention is effected in conventional manner by mixing the components withe aid of known mixing units (stirrers, rolls).

The compositions of the invention can be cured to crosslinked productsusing customary hardeners for epoxy resins. The invention accordingly relates also to compositions which, in addition to containing the above described components (A), (B) and (C), also contains a hardener (D) for epoxy resins and an optional accelerator (E).

Typical examples of hardeners (D) are aliphatic, cycloaliphatic, aromatic and heterocyclic amines such as bis(4-aminophenyl)methane, aniline/
formaldehyde resin, bis(4-aminophenyl)sulfone, propane-1,3-diamine, hexa-methylenediamine, diethylenetriamine, triethylenetetramine, 2,2,4-tri-methylhexane-1,6-diamine, m-xylylenediamine, bis(4-aminocyclohexyl)-methane, 2,2-bis(4-aminocyclohexyl)propane and 3-aminomethyl-3,5,5-tri-methylcyclohexylamine (isophoronediamine); polyaminoamides such as those obtained from aliphatic polyamines and dimerised or trimerised fatty acids; polyphenols such as resorcinol, hydroquinone, 2,2-bis(4-hydroxy-phenyl)propane and phenol/aldehyde resins; polythiols such as the polythiols commercially available as "Thiokols~"; polycarboxylic acids and anhydrides thereof, for example phthalic anhydride, tetrahydro-phthalic anhydride, hexahydrophthalic anhydride, hexachloroendomethylene-tetrahydrophthalic anhydride, pyromellitic anhydride, 3,3',4,4'-benzo-phenonetetracarboxylic dianhydride, the acids of the aforementioned anhydrides as well as isophthalic acid and terephthalic acid. Suitable hardeners are also carboxyl-terminated polyesters, especially if the curable mixtures of this invention are used as powder coating composi-tions for surface protection. It is also possible to use catalytic hardeners, for example tin salts of alkanoic acids, e.g. tin octanoate, Friedels-Craft catalysts such as boron trifluoride and boron trichloride and their complexes and chelates which are obtained by reacting boron trifluoride with e.g. 1,3-diketones; and substituted cyanamides such as dicyandiamide.

Examples of accelerators (E) are tertiary amines and salts or quaternary ammonium compounds thereof, such as benzyldimethylamine, 2,4,6-tris(di-methylaminomethyl)phenol, 1-methylimdiazole, 2-ethyl-4-methylimidazole, 4-aminopyridine, tripentylammonium phenolate or tetramethylammonium chloride; or alkali metal alcoholates such as sodium alcoholates of 2,4-dihdroxy-3-hydroxymethylpentane; or substituted ureas such as N-(4-chlorophenyl)-N',N'-dimethylurea or N-(3-chloro-4-methylphenyl)-N',N'-dimethylurea (chlortoluron).

Surprisingly, it is possible to cure a composition containing a high proportion of component (B) and optionally (C), for example more than 50 % by weight, based on the amounts of (A), (B) and (C).

Curing of the compositions of the invention can be effected at room temperature or at higher temperatures.

In general the curing temperatures for hot curing are in the range from80 to 250C, preferably from 100 to 180C. If desired, curing can also be carried out in two steps, for example by discontinuing the curing procedure or, if a hardener for higher temperatures is used, partially curing the curable composition at low temperature. The products so obtained are still fusible and soluble precondensates (B-stage resins) and are suitable, for example, for the preparation of moulding compounds, sintered powders or prepregs.

Components (B) and especially also (C) of the compositions of this invention effect a significant increase in the peel strength, and the cured products exhibit a diminished tendency to crack propagation and have high peel strength without loss of lap shear strength.

Depending on the resin formulation, it is possible to prepare with these modifiers elastic products of high peel strength and with low glass transition temperature or high-strength products with high glass transi-tion temperature and of high peel strength. The high-strength products display high resistance to crack formation, and crack propagation is markedly diminished even when the nroducts are subjected to very severe shock impact.

The properties of the cured final product can be varied in accordance with the proportion of components (A), (B) and optionally (C).

The following percentages relate in each case to the total weight of components (A), (B) and optionally (C).
.

If it is desired to obtain products having high strength, high glass transition temperature, high peel strength, high impact strength and high resistance to crack propagation (crack resistance), then the proportion of components (B) and optionally (C) should normally not exceed 60 % by weight. Systems of this type are normally heterogeneous. The lower limit will depend on the desired properties, for example peel strength. The proportion of components (B) and optionally (C) should normally be more than 5 % by weight, preferably more than 10 % by weight.

If, on the other hand, it is desired to obtain products of the highest possible flexibility, then the proportion of components (B) and optionally (C) should be not less than 40 % by weight, preferably more than 60 % by weight.

The weight ratio of (B) to (C) may vary within wide limits. The preferred range of (B) to (C) is 50:1 to 1:50, more particularly 20:1 to 1:10 and, most preferably, 5:1 to 1:5.

The proportion of the epoxy resin (A) to the total amount of (A), (B) and (C) may also vary within wide limits. For cured products of increased flexibility, small amounts of (A), for example 10 to 30 % by weight, will normally be used, which component (A) may also be in the form of an - _ 34 _ 1 335389 adduct with (B), whereas for cured products of high strength, substantial amounts of (A), for example 50 to 95 ~0 by weight, preferably 60 - 80 ~0 by weight, will normally be used.

If desired, reactive diluents, for example styrene oxide, butyl glycidyl ether, 2,2,4-trimethylpentyl glycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether or glycidyl esters of synthetic, highly branched, ..
mainly tertiary, aliphatic monocarboxylic acids, can be added to the curable mixtures to reduce their viscosity further.

The amount of hardener (B) or of accelerator (E) will depend on the type of hardener and will be chosen by the skilled person in a manner known per se. The preferred hardener is dicyandiamide. In this case, it is pre-ferred to use 0.1 - 0.5 mol of hardener per mol of epoxy groups.

As further conventional modifiers the compositions of this invention may contain plasticisers, extenders, fillers and reinforcing agents, for example coal-tar, bitumen, textile fibres, glass fibres, asbestos fibres, boron fibres, carbon fibres, mineral silicates, mica, powdered quartz, alumina trihydrate, bentonites, kaolin, silica aerogel or metal powders, for example aluminium powder or iron powder, and also pigments and dyes, such as carbon black, oxide colourants, titanium dioxide, flame re-tardants, thixotropic agents, flow control agents such as silicones, waxes or stearates (some of which can also be used as mould release agents), couplers, antioxidants and light stabilisers.

The cured products are distinguished by the advantageous properties described at the outset.

The invention therefore also relates to the crosslinked products obtainable by curing compositions which contain (A), (B), (D) and optionally (C) and (E).

The compositions of this invention can be used, for example, as adhesives, adhesive films, patches, matrix resins, lacquers or sealing compounds or, quite generally, for the preparation of cured products.
They can be used in a formulation adapted to suit each particular end ~ 335389 use, in an unfilled or filled state, as paints, coating compositions, lacquers, compression moulding materials, dipping resins, casting resins, impregnating resins, laminating resins, matrix resins and adhesives.

The invention also relates to the use of the compositions of this invention for the preparation of adhesives, adhesive films, patches, matrix resins, casting resins, coating compositions or sealing compounds.

As the compositions of this invention also have good adhesion to non-degreased objects, the present invention further relates to the use of the compositions for enhancing the compatability of adhesives with oil.

The invention is illustrated by the following Examples.

Examples A. Preparation of the components Phenol-terminated polyurethane lA
354 g of anhydrous polypropylene glycol (M = 2 OOO), 1.8 g of tri-methylolpropane and 0.1 ml of dibutyltin dilaurate are added at 100C and under nitrogen to 54.4 g of hexamethylene diisocyanate. After stirring the mixture at 100C for two hours and the isocyanate content has fallen below 4 %, this prepolymer is run at 80C into 135 g of anhydrous 3,3'-diallylbisphenol A, and the mixture is stirred for 2.5 hours at 80C
and for 30 minutes at 100C until free isocyanate is no longer detect-able. The following analytical data are obtained for the viscous resin:
viscosity ~40 = 128 600 mPa-s;
phenol content: 2.5 equivalents/kg;
molecular weight (GPC): M = 1260, M /M = 11.4.

Prepolymer for Example 1 A mixture of 33.3 g of carboxyl-terminated polybutadiene (Hycar~ CTB
2000 x 162, ex Goodrich), 66.6 g of dry ~-caprolactone and 0.3 g of dibutyltin oxide is heated, under nitrogen, for 2 hours to 220C. The mixture is then cooled to 140C and 150 g of bisphenol A diglycidyl ether - 36 - 1 3 3 5 3 ~ 9 (epoxy value: 5.4 Val/kg) and 2.5 g of triphenylphosphine are added. The batch is stirred for 2 hours at 140C, to give a viscous resin for which the following analytical data are obtained:
viscosity (according to Epprecht): 1560 mPa-s (80C) epoxy content: 2.9 Val/kg.

Prepolymers for Examples 2-9 Carboxyl-terminated butadiene/acrylonitrile copolymer (Hycar~ CTBN
1300 x 8 and 1300 x 13, ex Goodrich) and dry E-caprolactone are heated, under nitrogen, for 3 hours at the temperature indicated in Table 1 in the presence of 0.5 % of dibutyltin oxide. The properties of the com-pounds obtained are listed in Table 1. These carboxyl-terminated segmented polyesters are then reacted with an epoxy resin based on bisphenol A (epoxy value: 5.4 Val/kg) in the weight ratio of 1:1 by heating for 2 hours at 140C in the presence of 1 ~0 triphenylphosphine.
The properties of the epoxy adducts so obtained are listed in Table 1.

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Prepolymers for Examples 10-12 a) Preparation of butydiene/acrylonitrile copolymer epoxy resin adducts With stirring, 500 g of carboxyl-terminated butadiene/acrylonitrile copolymer (26 % acrylonitrile, 2.4 % carboxyl content, Hycar~ CTBN
1300 x 13, ex Goodrich) are reacted with 1000 g of bisphenol A diglycidyl ether (epoxy value: 5.4 Val/kg) for 3 hours at 140C in the presence of 2 g of triphenylphosphine. The resultant viscous resin has a viscosity (according to Epprecht) of 115 20 mPa-s (40C) and an epoxy value of 3.4 Val/kg.

b) Reaction of the epoxy resin adduct with E-caprolactone To 300 g of the adduct obtained in a) are added E-caprolactone in the amounts indicated in Table 2 and 2 g of dibutyltin oxide. The capro-lactone is grafted on to the adduct by heating for 4 hours to 190C. The analytical date are indicated in Table II.

Table II: Prepolymers for Examples 10-12 Example E-CaprolactoneViscosity (40C)Epoxy content (g) (mPa-s) (Val/kg) 100 34560 2.3 11 200 115200 1.7 12 300 125440 1.5 Prepolymer for Example 13 a) Preparation of the butadiene/acrylonitrile copolymer epoxy resin adduct In a ground glass flask equipped with stirrer, nitrogen inlet and reflux condenser, 730 g of bisphenol A diglycidyl ether (epoxy content:
5.4 Val/kg), 200 g of carboxylated-terminated acrylonitrile/butadiene copolymer (26 % acrylonitrile content, acid value 32 mg KOH/g, Hycar~ CTBN 1300 x 13, ex Goodrich), 64 g of bisphenol A and 5 g of triphenylphosphine are heated for 3 hours at 1 30C until a viscous resin with an epoxy content of 3.3 Val/kg and having a viscosity according to Epprecht of 130 000 mPas (40C) forms.

b) Reaction of the epoxy resin adduct with E-caprolactone In this Example, ~-caprolactone is added as reactive diluent to the mixture, and the butadiene/acrylonitrile caprolactone block copolymer is formed in situ during the curing of the epoxy resin adduct. This is brought about by further adding dibutyltin oxide as catalyst to the curable mixtures (q.v. Table III).

B. Preparation and testing of the adhesive compositions The components listed in Table III are mixed on a three-roll mill and used for bonding to degreased aluminium or steel. The test specimens with an overlap of 1.25 cm2 are cured for 1 hour at 180C.

The lap shear strength according to DIN 53 285 is determined using 1.5 mm thick steel and aluminium pieces which have been washed free of oil with methylene chloride.

The T-peel strength according to DIN 53 282 is determined using oil-free steel specimens having a thickness of 0.6 mm.

Table III: Adhesive compositions and test results Example A B A B A B A B A B A B

diglycidyl ether of bisphenol A 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 35 (epoxy content 5.4 Val/kg) (g) butanediol di-glycidyl ether 2 52.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 (epoxy content 9.2 Val/kg) (g) phenol-terminated 15 - 15 15 - 15 - 15 - 15 15 - 15 15 15 15 15 polyurethane lA (g) prepolymer (g) 32 15 32 15 15 32 15 32 15 32 15 15 32 15 15 15 15 15 15 ~-caprolactone (g) - - - - - - - - - - - - - - - - _ _ 7.5 dibutyltin oxide (g) - - - - - - - - - - - - - - - - - - 0.1 ~
dicyanidiamide (g)4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9 W
chlortolurone (g)0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 C3 wollastonite P1 )(g) 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 PY g 2) 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 silica (g) Table III: Adhesive compositions and test results (continuation) Example A B A B A B A B A B A B

lap shear strength 14.822.7 20 5 27 6 29 225 0 29.7 19.0 25.2 27.9 28.8 31.7 28.5 30.3 31.1 33.0 27.0 23.8 28.2 on Al (N/mm2) lap shear strength 20.923 8 13 1 23 5 21 924 6 23.0 16.1 21.4 21.0 25.3 25.0 24.6 23.7 25.1 26.7 24.1 21.0 27.1 on steel (N/mm2) T-peel strength n.d. 7.32.67.4 6.4 2.6 8.1 2.4 7.2 2.6 8.5 7.6 2.4 8.1 5.6 6.4 5.1 5.6 6.9 ) (N/mm2 ) fracture n.d. 80n.d.n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 70 70 70 70 ~~
(cohesion fracture in %) ) Sold by Interpace (Willsboro, N.Y.) ) Aerosil~9 380, ex Fa. Degussa ~
3) W
n.d. = not determined ~

Claims (17)

1. A composition comprising (A) an epoxy resin, (B) a block polymer containing at least one block (B1) of a 1,3-diene-homopolymer or -copolymer which contains, in addition to the diene component, 0.1 to 50 mol-%
of a vinylaromatic compound, acrylonitrile, methacrylonitrile or of an acrylic acid or methacrylic acid derivative and at least two blocks (B2) of a lactone homopolymer orcopolymer which contains, in addition to the lactone component, up to 10 % by weight of an alkylene oxide or a diol as co-component, and, if required, (C) a compound of formula I

(I), wherein m is 1 or 2, n is 2 to 6, R1 is the n-valent radical of an elastomeric prepolymer, which is soluble ordispersible in epoxy resins, after removal of the terminal isocyanate, amino or hydroxyl groups, X and Y each are independantly of the other -O- or -NK3-, with the proviso that at least one of these groups is -NR3-, R2 is an m + 1-valent radical of a polyphenol oraminophenol after removal of the phenolic hydroxyl groups or of the amino group, and R3 is hydrogen, C1-C6alkyl orphenyl, and, if required, (D) a hardener for epoxy resins, and, if required, (E) an accelerator.

2. A composition according to claim 1, wherein the epoxy resin (A) has an epoxy content of 2 to 10 equivalents/kg and is a glycidyl ether, a glycidyl ester or a N-glycidyl derivative of an aromatic, heterocyclic, cycloaliphatic or aliphatic compound.

3. A composition according to claim 2, wherein the epoxy resin (A) is a polyglycidyl ether of bisphenol A.

4. A composition according to claim 1, wherein the diene component of the block (B1) is butadiene.

5. A composition according to claim 1, wherein the co-component of the block (B1) is styrene, an acrylate, a methacrylate or acrylonitrile.

6. A composition according to claim 4, wherein the block (B1) is a butadiene/acrylonitrile copolymer or a butadiene homoploymer.

7. A composition according to claim 1, wherein the block length of the block (B1) is equivalent to a molecular weight Mn of 500 to 10000.

8. A composition according to claim 1, wherein the block polymer (B) contains not less than 20 % by weight of the 1,3-diene, based on the total weight of the blocks (B1) and (B2).

9. A composition according to claim 1, wherein the lactone component of the block (B2) is .epsilon.-caprolactone.

10. A composition according to claim 1, wherein the block length of the block (B2) is equivalent to a molecular weight Mn of 200 to 10000.

11. A composition according to claim 1, wherein the block polymer (B) contains glycidyl groups.

12. A composition according to claim 1, wherein the compound of formula I
is essentially free from isocyanate groups, contains at least two free phenolic hydroxyl groups, and is obtainable by reacting a1) an adduct of a substantially equivalent amount of a diisocyanate with a mixture of a dihydroxyl- or trihydroxyl-terminated polyether or polyester and less than 1 %, based on said hydroxyl-terminated prepolymer, of a diol or triol, and b) an amount of a bisphenol or trisphenol which is substantially equivalent to the content of NCO groups.

13. A glycidylated adduct obtainable by reacting a block polymer (B) which contains at least one block (B1) based on a 1,3-diene homopolymer or copolymer and at least two blocks (B2) of a lactone homopolymer or copolymer with a glycidyl group containing epoxy resin.

14. A glyeidylated reaction product obtainable by reacting a lactone with an adduct of a 1,3-diene homopolymer orcopolymer with a glycidyl group containing epoxy resin.

15. A crosslinked product obtainable by curing the composition of claim 1.

16. The use of the composition of claim 1 for the preparation of adhesives, adhesive films, patches, matrix resins, casting resins, coating compositions or sealing compounds.

17. The use of the compositions of claim 1 for enhancing the compatibility of adhesives with oil.