WO2003031495A1

WO2003031495A1 - Adducts consisting of epoxides and polyaminoamides containing imidazoline groups

Info

Publication number: WO2003031495A1
Application number: PCT/EP2002/011040
Authority: WO
Inventors: Wolfgang Scherzer; Jörg Volle
Original assignee: Vantico Gmbh & Co. Kg
Priority date: 2001-10-08
Filing date: 2002-10-02
Publication date: 2003-04-17

Abstract

The invention relates to an adduct, containing free amine hydrogens that can be obtained by reacting a) a polyaminoamide containing imidazoline groups, which in turn can be obtained by reacting a1) a polyethylene polyamine containing 5 or more amine hydrogens with a2) an acid containing between 2 and 40 C atoms, with b) a polyfunctional epoxide compound containing on average more than two epoxide groups per molecule. Said adduct is characterised in that the epoxide compound b) is selected from a tetraglycide of 4,4 diaminodiphenyl methane and a triglycide of aminophenol. The adduct is suitable for use as a curing agent for curable epoxy resin compositions, which are in particular suitable for use as adhesives, matrix resins, tooling resins or as coating agents.

Description

Adducts of epoxides and polyaminoamides containing imidazoline groups

The present invention relates to adducts obtainable by reacting polyaminoamides containing imidazoline groups with certain epoxy compounds, their use as hardeners for epoxy resins, curable mixtures based on these curing agents, and the use of these curable mixtures.

Curable mixtures based on aminic curing agents and epoxy resins are widely used in industry for coating and coating metallic and mineral substrates, as adhesives and sealants, as matrix resins, as tool resins or more generally as casting resins for the production of moldings or fabrics. In particular, aliphatic, cycloaliphatic or aromatic amines are used as amine curing agents. The mechanical and physical properties of the curable mixtures based on these amines are sufficient for many applications.

However, where amine compounds must be used from which low volatility is expected, pre-adducts of such amines with epoxy resins are used. The advantages are a lower vapor pressure and thus also less odor and toxicology. However, since the free amine content in such compounds is still very high, so-called "isolated adducts" are frequently used. The excess of free amine is separated off by distillation. The disadvantage of these compounds is, however, their far too high viscosity. At room temperature and lower In order to be processable at high temperatures, larger amounts of diluents have to be added, but this leads to a significant deterioration in the mechanical properties of the hardened thermoset, which is why aminoamides are often used, which consist of long-chain fatty acids and polyamines (see for example GB 988 484), in usually polyethylene polyamines, are produced by polycondensation, but in practice these products have disadvantages in many cases, such as massive tensile shear strengths, on various substrates.

It was therefore an object of the present invention to provide curing agents whose free amine content is comparatively low, but which at the same time are Room temperature low viscosity and can be processed without the addition of diluents, and the mechanical data of the hardened thermosets have a high level.

This object is achieved according to the invention by certain adducts which can be obtained by reacting polyaminoamides containing imidazoline groups with certain polyepoxides. The free amine content of these adducts is low (less than 5%) and the viscosities of such adducts enable processing at room temperature.

Surprisingly, the adducts according to the invention have significantly higher tensile shear strengths than the previously known polyaminoamides.

The invention therefore relates to adducts comprising free amine hydrogens, obtainable by reacting a) an imidazoline-containing polyaminoamide, obtainable by reacting a1) a polyethylene polyamine containing 5 or more than 5 amine hydrogens, with a2) an acid containing 2 to 40 ° C. -Atoms, with b) a polyfunctional epoxy compound containing an average of more than two epoxy groups per molecule, characterized in that the epoxy compound b) is selected from tetraglycide of 4,4-diaminodiphenylmethane and triglycide of aminophenol.

The imidazoline group-containing polyaminoamides are prepared by a process known per se by condensation of polyethylene polyamines and fatty acids. Amines containing 5 or more than 5 amine hydrogen atoms in the molecule, such as e.g. Diethylene triamine (DETA), triethylene tetramine (TETA), tetraethylene pentamine (TEPA), pentaethylene hexamine (PEHA) and higher polyethylene polyamines.

The acids or fatty acids with 2-22 C atoms used for the condensation with the polyethylene polyamines can contain monomeric, dimerized, trimerized, saturated or unsaturated hydrocarbon radicals. Fatty acids which contain at least 8 carbon atoms are preferred according to the invention. Monomeric, unsaturated fatty acids which contain at least 14 carbon atoms, such as oleic acid, tall oil fatty acid, linoleic acid, linolenic acid, and dimerized fatty acids are particularly preferred. Such fatty acids are available, for example, under the trademark Pripol from Unichema.

To produce the imidazole-containing polyaminoamides, the polyethylene polyamine is placed in the reaction vessel and the fatty acid is added at 60 ° C. to 100 ° C. The reaction mixture is heated to 260 ° C. and the water of reaction formed is distilled off. A polyamino amide is formed in a first condensation step and a polyamino amide containing imidazoline groups is formed therefrom in a second condensation step. The degree of conversion of the second condensation step can be adjusted via the amount of water distilled off and can be up to 90% with respect to the polyaminoamide of the first condensation step. For this reason, mixtures of at least 10 mol% of polyaminoamide and a maximum of 90 mol% of imidazoline-containing polyaminoamide are formed in practice. According to the invention, preference is given to product mixtures in which the polyaminoamides containing imidazoline groups are present to more than 50%, in particular to more than 70%. The molar ratio of polyethylene polyamine to acid groups is preferably from 1: 1 to 1: 1.5.

According to the invention, the polyepoxides used to adduct the polyaminoamides containing imidazoline groups are the tetraglycide of 4,4-diaminodiphenylmethane (Araldite HY 9663 from Vantico) and the triglycide of aminophenol (Araldite HY 500 HC from Vantico). According to the invention, the triglycide of aminophenol is preferred.

For the adducting, the imidazole-containing polyaminoamide is introduced and heated to 60 ° C to 100 ° C. The preheated polyepoxide compound to about 50 ° C is within about 60 min. added. To complete the reaction, allow 60 min. stirred. The triglycidyl isocyanurate is solid and is added in portions.

According to the invention, the adductation level is chosen so that 0.01 to 0.5, preferably 0.05 to 0.2, epoxy equivalents of the polyfunctional epoxy compound are accounted for per mole of the polyaminoamide compound containing imidazoline.

Another object of the invention is a curable composition containing c) an adduct containing free amine hydrogens, obtainable by reacting a) an imidazoline group-containing polyaminoamide, obtainable by reacting a1) a polyethylene polyamine containing 5 or more than 5 amine hydrogens, with a2) an acid containing 2 to 40 carbon atoms, with b) a polyfunctional epoxy compound containing an average of more than two

Epoxy groups per molecule, characterized in that the epoxy compound b) is selected from tetraglycide of 4,4-diaminodiphenylmethane and triglycide of

Aminophenol, and d) an epoxy resin with an average of more than one epoxy group per molecule.

The mixing ratio of c) to d) is preferably chosen to be equivalent, ie one epoxide equivalent is used per amine equivalent. However, depending on the intended use and the desired end properties of the hardened thermoset, an excess or deficit of the polyaminoamide adduct c) according to the invention containing imidazoline groups can be used.

The curable compositions can furthermore contain the curing agents customary in epoxy resin technology, in particular amine curing agents, as co-curing agents.

The invention further relates to the cured products obtainable by curing such a composition. The epoxy resins d) used can be cured hot and cold (room temperature) with the polyaminoamide adducts according to the invention containing imidazoline groups.

The epoxy resins can be cured in the presence of further additives, such as auxiliaries and additives customary in epoxy resin technology. For example, gravel, sands, silicates, graphite, silicon dioxide, talc, mica etc. are to be mentioned in the grain size distributions customary in this area. Pigments, dyes, stabilizers, leveling agents, plasticizers, non-reactive extender resins, plasticizers can also be used.

The epoxy compounds d) used according to the invention are commercially available products with on average more than one epoxy group per molecule, which are derived from mono- and / or polyvalent and / or polynuclear phenols, in particular bisphenols and novolaks, such as, for example, bisphenol A and bisphenol F diglycidylether. An extensive list of these epoxy compounds can be found in the manual "Epoxy compounds and epoxy resins" from AM Paquin, Springer Verlag Berlin, 1958, Chapter IV, and in Lee & Neville, "Handbook of Epoxy Resins", 1967, Chapter 2. Mixtures of two or more epoxy compounds d) can also be used.

Mixtures of glycidyl ethers based on bisphenol-A, bisphenol-F or novolaks with so-called reactive diluents, such as, for example, monoglycidyl ethers of phenols or glycidyl ethers based on mono- or polyhydric aliphatic or cycloaliphatic alcohols, are preferred according to the invention. Examples of such reactive diluents are, for example, phenyl glycidyl ether, cresyl glycidyl ether, p-tertiary butylphenyl glycidyl ether, butyl glycidyl ether, C ₁₂ -C ₄ alcohol glycidyl ether, butane diglycidyl ether, hexane diglycidyl ether, cyclohexane dimethyl or glycidyl ether based on polyglycidyl ether. If necessary, the viscosity of the epoxy resins can be further reduced by adding these reactive diluents.

The compositions according to the invention can be used quite generally as casting resins for the production of hardened products, and can be used in the formulation adapted to the respective field of application, for example as adhesives, as matrix resins, as tool resins or as coating agents.

The adducts according to the invention are particularly suitable for applications in the adhesive sector.

Examples:

Production of the imidazole group-containing polyaminoamides:

The polyethylene polyamine is placed in the reaction vessel and heated to about 60 ° C. with stirring. At 60 ° C to 100 ° C within 60 min. the fatty acid added continuously. After the addition, the reaction mixture is heated to 260 ° C. and the water of reaction formed is distilled off. The temperature is held for 2 hours.

Then allowed to cool to room temperature. The characteristics of this

Imidazoline group-containing polyaminoamides prepared in this way are shown in Table 1. Table 1 :

1) PEPA = polyethylene polyamine

TETA = triethylene tetramine

TEPA = tetraethylene pentamine

2) TFS = tall oil fatty acid

LS = linolenic acid

D 96 = Dimerized TFS with 96% dimer

3) AZ = amine number

4) NHA = amine equivalent

Production of the adducts

An imidazole group-containing polyaminoamide from Examples 1-5 is placed in the reaction vessel and heated to about 60 ° C. At 60 ° C - 90 ° C within approx. 60 min. added the polyepoxide. To complete the reaction, allow 60 min. Stir at 60 ° C to 80 ° C. The properties of the adducts produced in this way are shown in Table 2.

Table 2

Legend:

1) IAPAA = imidazole-containing polyaminoamide according to the example

2) Epoxy = polyepoxide from A = tetraglycide of diaminodiphenylmethane

(Epoxy equivalent (EPA): approx. 110) = polyepoxide from B = triglycid of aminophenol (EPA: approx. 100);

3) = polyamidoimidazole from TETA and tall oil fatty acid (Example 1)

Application Examples

The imidazole-containing polyamino amide adducts listed in Table 2 are mixed in equivalent amounts with the epoxy resin Araldite GY 260 (bisphenol A diglycidyl ether,

Epoxy equivalent weight 187, Vantico) stirred homogeneously and in accordance with DIN 53283

Steel sheet applied.

The tensile shear strengths were measured both after curing for 24 hours

Room temperature as well as after 7 days curing at room temperature. The measurement results are shown in Table 3 below.

Table 3

As can be seen from Table 3, the tensile shear strengths of the adducts according to the invention consisting of polyfunctional epoxides and polyaminoamides containing imidazole groups are significantly higher both after 24 hours / RT and after 7 days / RT than with the polyaminoamide from triethylenetetramine which is not adducted with a polyfunctional epoxide Tall oil fatty acid (Example 14). The free amine content of the products according to the invention is comparatively low (<5%). These products therefore have a low toxicology. The viscosities of these products, especially those based on more monomeric fatty acids are also comparatively low. Isolated adducts with a comparatively low amine content are generally solid or have viscosities of up to several hundred Pas at 25 ° C.

Claims

claims

1. Adduct containing free amine hydrogens, obtainable by reacting a) an imidazoline group-containing polyamino amide, obtainable by reacting a1) a polyethylene polyamine containing 5 or more than 5 amine hydrogens, with a2) an acid containing 2 to 40 carbon atoms b) a polyfunctional epoxy compound containing an average of more than two epoxy groups per molecule, characterized in that the epoxy compound b) is selected from tetraglycide of 4,4-diaminodiphenylmethane and triglycide of aminophenol.

2. Adduct according to claim 1, characterized in that a1) is selected from diethylene triamine (DETA), triethylene tetraamine (TETA), tetraethylene pentamine (TEPA), pentaethylene hexamine (PEHA).

3. Adduct according to one of claims 1 and 2, characterized in that a2) is a fatty acid containing 8 or more than 8 carbon atoms.

4. Adduct according to claim 3, characterized in that a2) is an unsaturated, monomeric fatty acid containing 14 or more than 14 carbon atoms.

5. Adduct according to one of claims 1 to 4, characterized in that in the reaction for 1 mole of component a) 0.01 to 0.5, preferably 0.05 to 0.2, epoxide equivalents of component b) are eliminated.

6. Adduct according to claim 1, characterized in that the epoxy compound b) is the triglycide of aminophenol.

7. Curable composition containing c) an adduct according to claim 1, and d) an epoxy resin with an average of more than one epoxy group per molecule.

8. Curable composition according to claim 7, characterized in that the epoxy resin with an average of more than one epoxy group per molecule is a bisphenol glycidyl ether or epoxy novolak.

9. Hardened product obtainable by curing a composition according to one of claims 7 and 8.

10. Use of a curable composition according to one of claims 7 and 8 as an adhesive, as a matrix resin, as a tool resin or as a coating agent.