SK4562001A3 - Impact-resistant epoxide resin compositions - Google Patents

Abstract

Condensation products comprised of carboxylic acid dianhydrides, diamines or polyamines, especially polyoxyalkylene amines and polyphenolene or aminophenolene are suited as structural constituents for epoxide resin compositions. In addition, these compositions contain conventional rubber-modified epoxide resins and liquid and/or solid polyepoxides and conventional hardeners and accelerators, and they optionally contain fillers and rheology auxiliary agents. The inventive compositions are suited as impact-resistant, impact-peel-resistant and peel-resistant adhesives used in vehicle manufacturing and in electronics. These adhesives exhibit very good impact-peel characteristics, especially at very low temperatures.

Description

Technical field

The present invention relates to mixtures of special copolymers with at least one polyamide or polyimide-terminated phenol having a glass transition temperature of at least -30 ° C and below, a mixture of these components with epoxy resins and / or epoxy resin adducts on a lower glass transition temperature copolymer and / or on polyamide or polyimide as well as thermally activatable latent hardeners of the resin components as well as optionally accelerators, fillers, thixotropic auxiliaries and other conventional additives. The invention further relates to a process for the production of these compositions as well as to their use as a reactive adhesive.

BACKGROUND OF THE INVENTION

Reactive hot melt adhesives are known. In the manufacture of machines, vehicles or apparatus, in particular in the manufacture of aircraft, rail vehicles or automobiles, components of various metal components and / or composites are increasingly bonded by means of adhesives. For structural adhesives with high strength requirements, epoxy adhesives are widely used, in particular as one-component hot-curing adhesives, which are often formulated as reactive hot-melt adhesives. Reactive hot-melt adhesives are adhesives which are solid and soft at room temperature only when they reach a temperature of approximately 80 to 90 ° C and behave as thermoplastic material. It is only at higher temperatures of approximately 100 ° C that the latent hardeners present in these adhesives are activated, so that an irreversible hardening to the thermosetting takes place. For joining components, for example in the automotive industry, the adhesive is first applied hot to at least one surface of the substrate, which is then bonded to the component to be joined. After cooling, the adhesive then solidifies and by this physical curing ensures sufficient handling strength, i. pre - connection. The parts so connected to each other are further forward

-2 ··· ········· · · ··· · · ··· · · ··· ··· ··· ··· ··· ··· , phosphating and varnishing baths. Only then does the adhesive cure in the furnace at higher temperatures.

Conventional adhesives and hot melt adhesives based on epoxy resins are hard and brittle when cured. As a result, the adhesives obtained have a very high tensile and shear strength. However, they exfoliate under the stress of splitting, impact or impact and splitting, especially at low temperatures, so that, in these types of stressing of the bonded joint, the connection is easily lost. There has therefore been a number of suggestions to modify epoxy resins in such a way that they are flexible additives so that their brittleness is clearly reduced. A common method is to use special rubber adducts on the epoxy resin that are deposited as a heterodisperse phase in the epoxy resin matrix, so that the epoxides will be more resilient. These epoxy resin compositions are also referred to as "Toughened". A conventional, known modification of epoxy resins of the above-mentioned type consists in the reaction of a polybutadiene-co-acrylonitrile copolymer with carboxyl end groups with an epoxy resin. The rubber-epoxy adduct is then dispersed in one or more different epoxy resins. The reaction of the epoxy resin with the carboxyl-terminated butadiene-acrylonitrile rubber must be carried out in such a way that it does not lead to premature curing of the adduct. Although such modified epoxy resin compositions are clearly superior in relation to impact resistance over unmodified epoxy resins, their behavior under the stress of grafting or impact and grafting is still inadequate.

EP-A-0 343 676 discloses hot-melt adhesive compositions comprising a mixture of a plurality of epoxy resins, a phenolic resin and a polyurethane epoxy adduct. The contained polyurethane-epoxy adduct consists of the reaction product of a plurality of polyalkylene glycol mono- and copolymers having primary and secondary OH groups, diisocyanate and at least one epoxy resin. It is reported that these hot melt adhesive compositions have improved shear resistance, chipping and impact resistance over various, commercial one-component hot melt adhesive compositions, and no data is provided on the properties of the adhesive-cured adhesive at low temperatures.

US-A-5 290 857 discloses an epoxy adhesive composition comprising an epoxy resin as well as a core / shell powder polymer and an epoxy resin hardener

-3 heat-activatable heat-activatable. The core / shell polymer powder is comprised of a core comprising an acrylate or methacrylate polymer having a glass transition temperature of -30 ° C or less and a shell comprising an acrylate or methacrylate polymer containing crosslinkable monomer units and having a glass transition temperature greater than or equal to 70 ° C. wherein the core to shell weight ratio ranges from 10: 1 to 1: 4. These compositions are said to have excellent adhesive properties such as impact resistance, tensile and shear resistance, and chipping resistance, and in addition have good partial gelling capability. Data on the properties of the joints glued by these adhesives at low temperatures are not given.

In an analogous manner, U.S. Pat. No. 5,686,509 discloses a composition with enhanced adhesion for epoxy resins consisting of powdered copolymer particles that are ionically crosslinked by mono- or divalent metal cations. The core / core region of the polymer comprises a diene monomer and optionally crosslinkable monomer units having a glass transition temperature less than or equal to -30 ° C. The shell copolymer has a glass transition temperature of at least 70 ° C and consists of acrylate or methacrylate monomer units and radically polymerizable unsaturated carboxylic acid units. The adhesive composition should comprise from 15 to 60 parts by weight of the enhanced adhesion powder copolymer and from 3 to 30 parts by weight of the heat-activatable curing reagent per 100 epoxy resin units. These compositions are recommended for use as structural adhesives for automotive parts. Data on low temperature properties of these bonded joints are not given.

EP-A-0 308 664 discloses epoxy resin compositions comprising an epoxy adduct of a carboxyl group-based copolymer based on butadiene acrylonitrile or similar butadiene copolymers, as well as a reaction product of an elastomeric prepolymer with end or is dispersible or amine-dispersible polyoxyphenol-soluble polyoxyphenol and the subsequent reaction of this adduct with an epoxy resin. Further, the compositions may comprise one or more epoxy resins. Furthermore, amine-functional hardeners, polyamino-4, are proposed to cure these compositions. Amides, polyphenols, polycarboxylic acids and their anhydrides or catalytic hardeners and optionally accelerators. It is stated that these compositions are suitable as adhesives which, depending on the particular composition, may have high strength, high glass transition temperature, high chipping resistance, high toughness or high crack resistance.

In an analogous manner, EP-A-0 353 190 describes epoxy resin compositions comprising an adduct of epoxy resin and a carboxylated butadiene acrylonitrile copolymer as well as a reaction product of a hydroxyl, mercaptan or amine group with a phenol carboxylic acid followed by reaction of the phenolic group with an epoxide. From EP-A-0 353 190 it can be found that these compositions are suitable for the production of adhesives, adhesive films, patches, sealants, lacquers or matrix resins.

According to the teachings of EP-A-0 354 498 or EP-A-0 591 307, hot-melt adhesive compositions can be prepared from a resin component, at least one thermally activatable latent resin hardener as well as an accelerator, fillers, thixotropic auxiliaries and other conventional additives. wherein the resin component is obtained by reacting one epoxy resin solid at room temperature and one epoxy resin liquid at room temperature with one or more linear or branched polyoxypropylenes having terminal amine groups. The epoxy resins are to be used in an amount relative to the amino-terminated polyoxypropylene in order to guarantee an excess of the epoxy groups with respect to the amino groups. These adhesive compositions already have high splitting resistance when attempting to split at an angle, which is retained even at low temperatures.

The object of the present invention is to improve the reactive adhesives of the initially mentioned type in such a way that they have sufficient flexibility, increased chipping resistance not only at room temperature but especially at low temperatures below 0 ° C. In particular, the resistance to chipping should be as high as possible at low temperatures and shock loads, so that the glued parts meet the modern safety requirements of the car construction even in the event of an accident (crash behavior). These improvements are to be achieved without limiting the high temperature cleavage resistance, as well as the tensile and shear strengths.

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In addition, reactive adhesives must have sufficient wash resistance immediately after application and before final curing. To do this, the adhesive compositions must be formulated as hot-melt adhesive, as hot-viscous adhesive. Another possibility is a formulation such as an adhesive which can be gelled by thermal pre-reaction in so-called "blast furnaces" or by induction heating of the parts to be joined.

SUMMARY OF THE INVENTION

The present invention provides compositions comprising:

A) copolymer with a glass transition temperature of at least -30 ° C and lower and with epoxy reactive groups as well as

(B) the reaction product of a diamine or polyamine with a carboxylic acid anhydride and a polyphenol or aminophenol, as well as

C) at least one epoxy resin.

In this case, components A), B) and C) can also be mixtures of compounds of the type mentioned. It is advantageous to react in separate reactions of components A) and B) with a large stoichiometric excess of epoxy resin and subsequently to optionally mix with other epoxy resins, thermally activatable hardeners and / or other additives.

Examples of copolymers of structural component A) are 1,3-diene polymers with carboxyl groups and other polar ethylenically unsaturated comonomers. The diene may be butadiene, isoprene or chloroprene, butadiene is preferred. Examples of polar, ethylenically unsaturated comonomers are acrylic acid. methacrylic acid, lower alkyl esters of acrylic or methacrylic acid, for example their methyl or ethyl esters, acrylic or methacrylic acid amides, fumaric acid, itaconic acid, maleic acid or their lower alkyl or semi-esters, or maleic or itaconic anhydride, vinyl esters such as vinyl acetate or in particular acrylonitrile or methacrylonitrile. Particularly preferred copolymers A) are carboxylic acid terminated butadiene acrylonitrile copolymers (CTBN), which are offered in liquid form under the trade name Hycar from B.F. Goodrich. These have molecular

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weight from 2000 to 5000 and acrylonitrile content from 10 to 30%. Specific examples are Hycar CTBN 1300 X 8.1300 X 13 or 1300 X 15.

In addition, the core / sheath polymers known from US-A-5 290 857 or US-A-5 686 509 can also be used as structural component A). The core monomers should have a glass transition temperature of less than or equal to -30 ° C, these monomers may be selected from the group of the aforementioned diene monomers or suitable acrylate or methacrylate monomers, or the core polymer may contain a small amount of crosslinkable comonomer units. The coating consists of copolymers having a glass transition temperature of at least 60 ° C. The coating is preferably composed of lower alkyl acrylate or methacrylate monomer units (methyl or ethyl ester) as well as polar monomers such as (meth) acrylonitrile, (meth) acrylamide, styrene or radically polymerizable unsaturated carboxylic acids or carboxylic acid anhydrides.

However, adducts of epoxy resins and of the aforementioned liquid CTBN rubbers are particularly preferred for structural component A).

Component B) can be represented by the following formula I

R ¹ ... [N | - (C = O) - X - (C = O) ™ Y - R ³ ™ (Z) _m ] n (I)

I

R ² where:

m = 1 or 2, n = 2 or 3,

R ¹ amino-terminated polyalkylene glycol residue after removal of functional groups,

R ² = H, C 1 to β-alkyl, -aryl or - (C = O) -, wherein for R ² = - (C = O) - both carbonyl groups, nitrogen and X form a five-membered cyclic imide ring,

X = C ₂ to β-alkyl or a carboxylic acid aromatic anhydride or dianhydride residue after removal of the cyclic anhydride groups,

Y = -O-, -S- or -NR ⁴ -, wherein R ⁴ = H or C 1 -C ₄ -alkyl or phenyl,

R ³ = carbocyclic-aromatic or araliphatic m + 1-valent radical with Z groups attached directly to the aromatic ring and Z = O, H or -NHR ⁴ .

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In this case, component B) is the reaction product of one diamine or polyamine and one carboxylic acid anhydride, the stoichiometric ratio being chosen so that the carboxylic acid anhydride is preferably in a double excess to the amino groups, then the remaining carboxylic acid anhydride groups or carboxylic acid groups are reacted. with polyphenol or aminophenol in stoichiometric excess in such a way that the condensation product has phenol or amine end groups. This condensation product is usually admixed directly into the composition according to the invention, but it is also possible to react it with a large stoichiometric excess of epoxy resin so as to form a condensation product with terminal epoxy groups.

In principle, a plurality of diamines or polyamines may be used for the condensation, but polyalkylene glycols with terminal amine groups are preferred, in particular polypropylene glycols, polyethylene glycols or copolymers of propylene glycol and ethylene glycol terminated with two- or three-functional amino groups. These are also known as "Jeffamin" (the trade name of Huntsman). Further particularly suitable are amino-terminated polyoxytetramethylene glycols, also called poly-THF. In addition, polybutadienes terminated with amine groups are suitable as structural components. The amino-terminated polyalkylene glycols have a molecular weight of from 400 to 5000.

Examples of suitable carboxylic acid anhydrides are maleic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, corkic acid, azelaic acid or sebacic acid or, in particular, aromatic carboxylic acid anhydrides or dianhydrides or their hydrogenation products such as phthalic anhydride, acid anhydride benzenetricarboxylic acid, tetrahydrophthalic dianhydride, melofanoic dianhydride, pyromellitic dianhydride, 1,8: 4,5-naphthalene dianhydride or 2,3: 6,7-naphthalene-tetracarboxylic acid dianhydride, perylene dianhydride, biphenyl tetracarboxylic acid dianhydride, biphenyl tetracarboxylic acid dianhydride, diphenylmethanetetracarboxylic acid, 2,2-diphenylpropanetetracarboxylic acid dianhydride or benzophenontetracarboxylic acid dianhydride as well as mixtures thereof.

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In addition to the aforementioned carboxylic anhydrides, maleic oils and fats may also be used as the anhydride component for the production of the condensation product B). Maleinized oils and fats as well as lower molecular polyenes are prepared in a known manner by reaction or free radical reaction of maleic anhydride with unsaturated compounds.

The polyphenols or aminophenols used for the condensation product B) are either aromatic di- or trihydroxy compounds which are derived from a carbocyclicaromatic radical having one or more cores, or they are the corresponding amino-hydroxy compounds. The aromatic rings can be either fused or linked to each other by means of bridging members or by a covalent bond.

Examples of the former are hydroquinone, resorcinol, pyrocatechin, dihydroxynaphthalene isomers (pure isomers or a mixture of multiple isomers), dihydroxyantracene isomers as well as the corresponding amino-hydroxy compounds. The polyphenols or aminophenols which are derived from carbocyclic aromatic compounds whose aromatic nuclei are linked by bridging members can be represented by the general formula II:

Z — AR — B — AR — Z (II) wherein Z is as defined above,

AR represents a mononuclear aromatic radical which may be optionally substituted by an alkyl or alkenyl radical.

B is a bridging member, which may be selected from the group consisting of a covalent bond, -CR ⁵ R ⁶ -, -O-, -S-, SO 2 -, -CO-, -C00-, -CONR ⁷ -, and SiR ⁸ R ⁹ . R ⁵ , R ⁶ and R ⁷ independently of one another are hydrogen, -CF ₃ or C 1 -C 6 -alkyl or R ⁵ and R ⁶ together form a C 5 -C 7 cycloaliphatic radical with a common carbon atom, R ⁸ and R ⁹ represent C 1 -C 6 - alkyl. In this case, the two groups B and Z of the formula II can be arranged independently of one another in the ortho-, meta- or para- position. Particularly preferred compounds of formula II are 4,4'-dihydroxy-diphenyl or bisphenols A and / or F.

Suitable epoxy resins for component C) or for epoxy adduct formation or for the mixing of components A) and B) are suitable amounts of polyepoxides which

-9 ·········································· They have at least two 1,2-epoxide groups per molecule. The epoxide equivalent of these polyepoxides may vary in the range of from 150 to 4000. The polyepoxides may in principle be saturated, unsaturated, cyclic or acyclic, aliphatic, alicyclic, aromatic or heterocyclic polyepoxide compounds. Examples of suitable polyepoxides include polyglycidyl ethers which are made by reacting epichlorohydrin or epibromohydrin with polyphenol in the presence of alkali. Suitable polyphenols are, for example, resorcinol, pyrocatechin, hydroquinone, bisphenol A (6 / s- (4-hydroxyphenyl) -2,2-propane, bisphenol F (b / s- (4-hydroxyphenyl) methane), (6 / s- (4-hydroxyphenyl) -1,1-isobutane, 4,4'-dihydroxybenzophenone, N / a (4-hydroxyphenyl) -1,1-ethane, 1,5hydroxynaphthalene.

Other principally suitable polyepoxides are polyglycidyl ether from polyalcohols or diamines. These polyglycidyl ethers are derived from polyalcohols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol or trimethylolpropane.

Other polyepoxides are polyglycidyl esters of polycarboxylic acids, for example from the reaction of glycidol or epichlorohydrin with aliphatic or aromatic polycarboxylic acids such as oxalic acid, succinic acid, glutaric acid, terephthalic acid or dimeric fatty acid.

Other epoxides are derived from the epoxidation products of olefinically unsaturated cycloaliphatic compounds or from natural oils and fats.

Particularly preferred are epoxy resins derived from the reaction of bisphenol A or bisphenol F and epichlorohydrin. As a rule, mixtures of liquid and solid epoxy resins are used, the liquid epoxy resins being preferably based on bisphenol A and having a sufficiently low molecular weight. In particular, room temperature epoxy resins having an epoxy equivalent weight of from 150 to about 220 are used to form the adduct of components A) and B), and an epoxy equivalent weight range of 182 to 192 is particularly preferred.

The hardness of the reactive adhesive in the cooled state, i. in particular after application to the substrate to be bonded, but before curing, depends on the degree of condensation and hence on the molecular weight, in particular of component B), as well as the ratio of the solid epoxy resin to the liquid epoxy resin. The higher the degree of condensation (and thus the molecular · · · · · ·

-10% weight of the condensation product B) and the higher the proportion the solid epoxy resin in the composition, the harder the cooled, semi-crystalline adhesive.

Guanidines, substituted guanidines, substituted ureas, melamine resins, guanamine derivatives, cyclic tertiary amines, aromatic amines and / or mixtures thereof may be used as a thermally activatable or latent hardener for an epoxy bonding system composed of components A), B) and C). The curing agents can be used in the curing reaction in a stoichiometric amount, but they can also act catalytically. Examples of substituted guanidines are methylguanidine, dimethylguanidine, trimethylguanidine, tetramethylguanidine, methylisobiguanidine, dimethylisobiguanidine, tetramethylisobiguanidine, hexamethylisobiguanidine, hepamethylisobiguanidine, and especially (cyanidine diamide). Representative of suitable guanidine derivatives are alkylated benzoguanamine resins, benzoguanamine resins, or methoxymethylethoxymethylbenzoguanamine. Of course, for heat-curing one-component hot-melt adhesives, the selection criteria are low solubility of these substances at room temperature in the resin system, so that solid, finely ground hardeners are preferred, dicyandiamide being particularly suitable. This ensures good storage stability of the composition.

Catalytically active substituted ureas may be used in addition to or in place of said hardeners. These are in particular p-chlorophenyl- N, N -dimethylurea (Monuron), 3-phenyl-1,1-dimethylurea (Fenuron) or 3,4-dichlorophenyl- N, N -dimethylurea (Diuron). In principle, it is also possible to use catalytically active tertiary acrylic or alkyl amines, such as benzyldimethylamine, cis (dimethylamino) phenol, piperidine or piperidine derivatives, but these often have too high solubility in the adhesive system, so that the usable stability of the one-component system is not achieved. storage. Furthermore, various, preferably solid, imidazole derivatives can be used as catalytic accelerators. Representatives are 2-ethyl-2-methylimidazole, N-butylimidazole, benzimidazole as well as N-C 1 to C 12 -alkylimidazoles or N-arylimidazoles.

The adhesives according to the invention further contain, as a rule, fillers known per se, such as various milled or precipitated chalks, carbon black, magnesium carbonates, barite, and in particular silicate fillers of the aluminum magnesium calcium silicate type, for example wollastonite, chlorite.

-11 · • w 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11

Furthermore, the adhesive compositions of the invention may contain conventional additional excipients and additives such as plasticizers, reactive diluents, rheological auxiliaries, wetting agents, anti-aging agents, stabilizers and / or color pigments.

On the one hand, the adhesives according to the invention can be formulated as one-component adhesives, which can also be formulated as highly viscous hot-melt adhesives as well as thermosetting hot-melt adhesives. Further, the adhesives may also be formulated as one-component pregelatinized adhesives, in the latter case the compositions comprising either fine thermoplastic powders such as polymethacrylate, polyvinylbutyral or other thermoplastic (co) polymers, or the curing system is so shielded that a two-stage curing process the gelling step causes only partial curing of the adhesive and the final curing is carried out in the manufacture of an automobile, for example, in a paint furnace, more preferably in KTL furnaces.

The adhesive compositions according to the invention can also be formulated as two-component epoxy adhesives in which the two reactants are mixed with each other only shortly before application, and the curing can then be carried out at room temperature or at a slightly elevated temperature. Known reactants of two-component epoxy adhesives, for example diamines or polyamines, amino-terminated polyalkylene glycols (for example Jeffamin, amino-poly-THF) or polyaminoamides, can be used as the second reactant. Other reactive partners may be mercaptan group prepolymers such as liquid thiocolymers. In principle, the epoxy compositions of the invention may also be cured with carboxylic anhydrides as the second reactant in the two-component adhesive formulation.

In addition to the aforementioned applications, the adhesive compositions of the invention can also be used as potting compounds in the electrical or electronics industry, as die-attach adhesives in electronics for bonding components to printed circuit boards. Other applications of the compositions of the invention are matrix materials for composites such as fiber reinforced composites.

However, a particularly preferred field of application of the adhesives according to the invention is structural adhesives in automobile manufacturing.

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-12 ··· ··· ··· ·· ···

Depending on the profile of the adhesive requirements due to its processing properties, flexibility, impact resistance, impact and splitting resistance, or tensile strength, the quantitative ratios of the individual components may vary within relatively wide limits. Typical ranges for essential ingredients are:

Component A): from 5 to 25 wt.%, More preferably from 10 to 20 wt.

Component B): from 5 to 30 wt.%, More preferably from 5 to 20 wt.

Component C): from 10 to 45% by weight, preferably from 15 to 30% by weight, which component consists of one or more liquid and / or solid epoxy resins, optionally containing lower molecular epoxides as reactive diluents, • fillers: from 10 to 40% by weight, • curing components (for thermally cured one-component systems): from 1 to 10% by weight, preferably from 3 to 8% by weight, • accelerators: from 0.01 rheological auxiliaries (thixotropic agents): from 0.5 to 5 wt.% to 3 wt.%, more preferably from 0.1 to 0.8 wt.

As mentioned at the outset, the requirements for modern structural adhesives in vehicle manufacturing are steadily increasing, as more and more components are bonded together. As already mentioned in the article by G. Kôtting and S. Singh, "Adhesive requirements for structural bonding in bodywork", Adhesion 1988, workbook 9, pages 19 to 26, adhesives must satisfy, on the one hand, the practical aspects of production, to this include automated processing in short cycle times, adhesion to oiled sheets, adhesion to different types of sheets as well as compatibility with the coating line process conditions (resistance to rinsing and phosphating baths, curing during KTL priming, resistance to subsequent painting and drying operations) . In addition, even when cured, modern structural adhesives have to meet the increasing strength and formability properties. This includes high corrosion resistance or bending stiffness of structural parts as well as deformability of the bonded joint by mechanical loading. As far as possible the high formability of the components guarantees a considerable safety advantage in the event of an accident (crash-behavior) in an accident. This behavior can best be ascertained by determining the impact energy for the cured adhesive bond, while the desired or desired

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even at high temperatures up to + 90 ° C, and especially at low temperatures up to 40 ° C, high impact energy values are sufficiently high. In addition, the tensile and shear strengths which are as high as possible should also be achieved. Both strengths must be achieved on a number of substrates, in particular oiled plates such as body steel plates, galvanized steel sheets by various methods, sheets of different aluminum alloys or even magnesium alloys, as well as coilcoating organic-coated steel sheets "Bonazinc" or "Granocoat". Surprisingly, as will be shown in the following examples, the adhesive compositions according to the invention meet these requirements to a very high degree.

The following examples are intended to illustrate the invention in more detail. For compositions, all amounts are by weight unless otherwise indicated.

DETAILED DESCRIPTION OF THE INVENTION

General production of component A)

Under nitrogen atmosphere and with stirring, the carboxyl-terminated poly (butadiene-co-acrylonitrile) (Hycar CTBN 1300 X 13) was reacted at 140 ° C for 3 hours with an approximately 10 molar excess of liquid DGEBA-epoxy resin to the stability of the reaction.

General production of the condensation product B) moles of carboxylic anhydride or dicarboxylic acid anhydride is reacted in a heating reaction vessel with a stirrer under nitrogen atmosphere at 120 ° C to 160 ° C with 0.4 to 0.7 mol amino-terminated polyalkylene glycol for 3-4 hours. wherein the polyamine is initially heated to a temperature of 130 ° C first. The adduct thus formed reacts with about 1.1 to 1.5 moles of polyphenol up to the stability of the reaction. The progress of the reaction was monitored by gel permeation chromatography (GPC). This phenol-terminated polymer is then mixed with an epoxy resin, more preferably bisphenol A diglycidyl ether (DGBEA).

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General adhesive production

In the blender, the components A), B) and the liquid epoxy resin and the solid epoxy resin are mixed at room temperature or 80 ° C, respectively, with the addition of fillers, hardeners, accelerators and rheological auxiliaries until homogeneity and subsequently and optionally still warm. filled into storage tanks.

Examples 1 to 6

According to the general production of the condensation product B), the condensation products B) shown in Table 1 were prepared from Jeffamine D-2000 (polyoxylpropylenediamine, molecular weight 2000), pyromellitic dianhydride and resorcinol.

Table 1

Example 1 2 3 4 5 6 D-2000 219.0 229.5 222.0 235.5 237.5 200.0 PMSA 48.0 42.0 48.0 41.4 36.9 31.3 resorcinol 33.0 28.5 30.0 31.2 25.5 18.7

D-2000 = Jeffamine D-2000

PMSA = pyromellitic dianhydride

Component A) was produced according to the above method from Hycar CTBN 1300 X 13 and liquid DGEBA resin. The result was a composition with 40% butyl rubber and an epoxy equivalent weight of 900, a viscosity at 80 ° C of 200 Pa.s.

Examples 7 to 12

The adhesive compositions of the invention were prepared from components B) according to Examples 1 to 6, component A) as well as liquid DGEBA resin (epoxy equivalent weight 186), fillers, dicyandiamide as hardener as well as accelerators and hydrophobic silica as a thixotropic agent. The compositions are summarized in Table 2.

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Table 2: Adhesives according to the invention

Example 7 8 9 10 11 12 component B) of Example 1 13.5 component B) of Example 2 13.5 component B) of Example 3 13.5 component B) of Example 4 13.5 component B) of Example 5 13.5 component B) of Example 6 13.5 component A) 17.0 17.0 17.0 17.0 17.0 17.0 DGEBA-liquid resin 28.0 28.0 28.0 28.0 28.0 28.0 wollastonite 33.7 33.7 33.7 33.7 33.7 33.7 dicyandiamide 4.5 4.5 4.5 4.5 4.5 4.5 fenuron 0.3 0.3 0.3 0.3 0.3 0.3 silicic acid, hydrophobic 3.0 3.0 3.0 3.0 3.0 3.0

wollastonite = filler silicic acid: Cabosil TS 720

Table 3 compares the adhesive properties of the examples according to the invention and the adhesive properties of the prior art adhesives. The adhesive of Comparative Example 1 was Terokal 5051 from Henkel Teroson, which adhesive was made based on the teachings of EP-A-0 354 498. The adhesive of Comparative Example 2 was Betamate 1044/3 from Gurit Essex. It is believed that this adhesive was produced based on the teaching of EP-A-0 308 664.

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-16Table 3: Adhesive-Technical Properties

Example 7 8 9 10 11 12 Cf.. example 1 Cf.. example 2 Impact -40 “C [J] 8.7 11.7 9.4 13.1 6.7 0.7 0.5 3.3 Impact -20 ’C [J] 12.7 14.7 13.4 16.2 10.5 1.9 0.4 2.6 Impact 0 ’C [J] 13.2 13.6 15.0 16.8 12.1 3.9 0.9 4.4 Impact room temperature [J] 15.5 14.7 16.1 16.0 12.9 5.0 2.1 5.2 PTS -40'C [MPa] 34.1 scf 31,1 scf 25,2 scf 30,9 Cf 28,4 cf 37.8; Ca 80% 19,8 cf 20,2 Cf PTS room temperature [MPa] 25,7 cf 22,7 cf 21,6 cf 22,5 cf 18.7 cf 16.4; Ca 80% 21,8 cf 21,6cf PTS +90 ’C [MPa] 14.8 cf 11,9 cf 11,4 cf 12,0 cf 11.0 cf 12,4cf 10,9 cf 11.1 cf 500 h TSK 20,3 cf 17.0 cf 17.0 cf 18,9 cf 17.0 cf did not. 19,3 cf 18,8 cf 1000 h TSK 19.1 cf 17,9 cf 14,5 cf 18.2 cf 16.6 cf did not. 17,5 cf 16.7 cf

Impact: impact and splitting test according to ISO 11343 at 2 m / s

PtS: tensile and shear strength according to DIN 53283

TSK: salt chamber test according to DIN 50021 cf: 100% cohesive break, unless otherwise specified scf: cohesive break with partial film residue on substrate

As can be seen from these experimental results, the impact and chipping energy according to ISO 11343 of the adhesives of the invention is many times higher than that of the prior art adhesives. Especially at very low temperatures, the impact and chipping energy of the adhesives of the invention is clearly superior to that of the prior art adhesives without adversely affecting the tensile and shear strength or aging behavior of the salt chamber test.

Claims (14)

PATENT CLAIMS Compositions prepared by reacting a carboxylic acid anhydride or a carboxylic acid dianhydride with a diamine or polyamine and a polyphenol or aminophenol, characterized in that the stoichiometric ratio is selected so that the carboxylic acid anhydride is more preferably in a double excess to the amino groups and the remaining carboxylic anhydride groups or carboxylic acid groups are subsequently reacted with the polyphenol or aminophenol in stoichiometric excess in such a way that the condensation product has phenolic or amine end groups. 2. Compositions comprising: (A) a copolymer with a glass transition temperature of at least -30 ° C or less and epoxy-reactive groups; B) a reaction product produced by reacting a carboxylic acid anhydride or a carboxylic acid dianhydride with a diamine or polyamine and a polyphenol or aminophenol according to claim 1, C) at least one epoxy resin. Compositions according to claim 2, characterized in that component A) is a butadiene-based copolymer. Compositions according to claim 2 or 3, characterized in that component A) is a carboxyl-terminated copolymer based on butadiene acrylonitrile, butadiene ester of (meth) acrylic acid, butadiene acrylonitrile styrene copolymer or butadiene (meth) acrylate-styrene copolymer. Composition according to claim 2, characterized in that component A) is a core-shell polymer, the core polymer of which is a diene polymer or a (meth) acrylate polymer having a glass transition temperature of -30 ° C or less and optionally crosslinked with from 0.01 to 5 wt. a diolefinic comonomer and having a coating polymer having a glass transition temperature of 60 ° C or greater and consisting of -18 alkyl group monomers (meth) acrylate, (meth) acrylonitrile, (methyl) styrene and olefinically unsaturated carboxylic acids or carboxylic acid anhydrides or mixtures thereof. Composition according to at least one of the preceding claims, characterized in that the epoxy resin adduct and copolymer adduct according to claims 2 to 5 is used as component A). Composition according to at least one of the preceding claims, characterized in that component B) is prepared by a condensation reaction of a) a carboxylic anhydride selected from the group of maleic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, pimelic anhydride, corkic anhydride, azelaic anhydride or sebacic anhydride or phthalic anhydride, benzenetricarboxylic acid anhydride, dianhydride melophanic acid, pyromellitic dianhydride, 1,8: 4,5-naphthalene- or 2,3: 6,7-naphthalene-tetracarboxylic acid dianhydride, perylenedianhydride, biphenyl-tetracarboxylic acid dianhydride, diphenyl ether-tetracarboxylic acid dianhydride, diphenyl dianhydride, dianhydride, - diphenylpropanetetracarboxylic acid, benzophenontetracarboxylic acid dianhydride or mixtures thereof, and (b) a polyamine selected from the group of polyethylene glycolamine, polypropylene glycolamine, polyoxytetramethylene amine or polybutadiene-di- or triamine; and c) polyphenol or aminophenol. in Composition according to claims 2 to 7, characterized in that component B) according to claim 7 is dissolved in liquid polyepoxide. Composition according to claims 1 to 5, characterized in that component B) according to claim 7 is reacted with a stoichiometric excess of polyepoxide. • ······················ -19 ·· ··· ·· · Composition according to at least one of the preceding claims, characterized in that, in addition to components A), B) and C), it comprises: A) latent hardener from the group of dicyandiamide, guanamines, guanidines, aminoguanidines, solid aromatic diamines and / or hardening accelerator, as well as B) optionally a plasticizer, reaction diluent, rheological auxiliaries, fillers, wetting agents and / or anti-aging agents and / or stabilizers. A process for curing components A), B), C), D) and optionally E) according to claim 10), characterized in that the composition is heated to a temperature of from 80 ° C to 210 ° C, more preferably from 120 ° C to 180 ° C. Use of a composition according to claim 10 as a high strength, impact resistant structural adhesive in the manufacture of automobiles, aircraft or rail vehicles. Use of the compositions according to claim 10 for the production of composites as potting compounds in the electrical and electronics industries as well as die-attach adhesives in the production of printed circuits in the electronics industry. 14. A method of bonding metal and / or composite materials comprising the following essential process steps: - applying an adhesive composition according to claim 10 to at least one surface of the substrate to be bonded, optionally after prior cleaning and / or surface treatment, - joining of parts, - optionally pre-gelling the adhesive composition, curing the bonded joint by heating the parts to a temperature in the range of 80 ° C to 80 ° C