CS240069B1 - Hardenable epoxy composition - Google Patents

Abstract

Improved epoxy processability the compositions are achieved by the use of a novel a type of hardener that allows it simultaneously improved incorporation of reactive diluents into the macromaleicular skeleton. Essence the solution is that they contain the compositions 100 wt. epoxy resin parts 5 to 50 wt. hardener parts based on products reaction of lower aldehydes with amines a optionally up to 50 parts by weight reactive diluents in the form of specified keto compounds, esters of unsaturated carboxylic acids and fehols, up to 3 wt. parts of pigments or fillers and up to 40 wt. other parts additive

Description

Curable epoxy compositions

Improvement of the workability of the epoxy compositions is achieved by the use of a new type of hardener, which simultaneously allows for better incorporation of reactive diluents into the macromalocular skeleton. The essence of the solution is that the compositions contain 100 wt. parts of epoxy resin, up to 50 wt. parts of hardener based on reaction products of lower aldehydes with amines and optionally up to 50% by weight, parts of reactive diluents of the specified ketone compounds, unsaturated carboxylic acid esters and fehols, up to 3% wt. parts of pigments or fillers and up to 40 wt. parts of other additives.

240 069

240 069

The present invention relates to curable compositions based on epoxy resins containing a hardener to achieve different pot life of curable compositions and thereby to prepare systems for a variety of applications.

Uncured epoxy resins, with the exception of high molecular weight types, have very limited application properties. They form liquid to solid thermoplastic materials which are wetted, soluble in a variety of organic solvents and therefore unusable for common applications. Only by curing do they acquire the properties that are the reason for their wide use in technical practice. The most commonly used curing systems include polyamines (e.g., U.S. Pat. No. 4,007,160, U.S. Pat. No. 2,611,019, Japanese Pat.

082400, 51 098732 and 52 021093, belg. U.S. Pat. 661 056, 867 589 etc.), especially aliphatic and cycloaliphatic (M. Lidařík et al .: Epoxy resins, SNTL, Prague 1983 pp. 144 - 145), which are capable of curing epoxy resins and compositions based on them at normal or slightly elevated temperatures. However, their defect is that the resins and compositions cured by them have a limited pot life and that they react mainly with epoxy or even hydroxyl groups, which greatly limits their scope of use. In the absence of lower viscosity systems, it is necessary to add diluents if necessary to reduce the consistency of the compositions. Since non-reactive diluents are unusable for most applications of epoxy curable compositions, reactive types, especially liquid glycidyl ethers, are readily employed here, which, unlike other reactive diluents, are readily incorporated into the compositions when cured with polyamine hardeners. The major disadvantage of using these substances, however, is their severely adverse physiological effects.

The present invention is directed to curable epoxy compositions based on dian or novolak type epoxy resins, polyamine hardeners and optionally reactive modifying compounds, fillers, pigments and other additives. It is an object of the invention that the compositions consist of 100 wt. parts of epoxy resin of dian or novolak type with a mol. 340 to 900 and 5 to 50 wt. parts of a hardener based on the reaction products of aldehydes having a carbon number of 1 to 7 with aliphatic and / or cycloaliphatic amines having a number of carbon atoms of 2 to 18 and nitrogen atoms of 1 to 5 in mol. ratio 1; 0.8 to 1.2. In addition to these components, up to 50 wt. parts of ketone compounds having at least one active hydrogen atom capable of addition reactions in the (-) position, preferably diacetone alcohol, cyclohexanone, methylcyclohexanone and 2- (1-cyclohexenyl) cyclohexanone, further alkyl, aralkyl, aryl esters and polyalkylether esters of K, unsaturated monocarboxylic and dicarboxylic acids, preferably acrylic, methacrylic, maleic and fumaric acids, having a carbon number of 1 to 300 and phenols having a carbon number of 6 to 18, up to 300 parts by weight of pigments and / or fillers and up to 40 parts by weight of additives from the group of plasticizers, colorants, surfactants, fungicides, corrosion inhibitors and blowing agents.

The compositions according to the invention have advantageous workability even with the simplest composition, where they consist only of <

, w

240 069 of epoxy resin and hardener prepared by reaction of aldehydes with amines. E.g. when using a palm type epoxy resin of mol. weight 400 and a hardener based on the reaction product of diethylenetriamine and formaldehyde, a hard gel is formed at 20 ° C already after 60 to 90 minutes, the composition having a good workability after mixing the components for 45 minutes. However, the advantages of the compositions according to the invention are particularly apparent in the addition of reactive modifying compounds of the type specified above, keto compounds, unsaturated acid esters and phenols. These substances greatly reduce the viscosity of the reaction mixtures and are incorporated into the macromolecule backbone during curing by reacting the hardener with the compounds in addition to the hardener reaction with the epoxy resin. Because this reaction is exothermic, it will allow for better curing of the composition, especially when applied in a lower temperature environment. Moreover, depending on the type used, these substances react with the hardener at different rates, so that systems with very different pot life can be prepared. At the same time, the viscosity of the resins or the viscosity of the resins can be controlled to a large extent by the type and amount of these compounds. consistency of the compositions, allowing the preparation of reactive mixtures for a wide variety of applications, from very viscous sealants to low viscosity systems, suitable for grouting, pouring flooring or plastics. The addition of said modifying additives also favorably affects the surface tension of the compositions. The effect achieved is particularly evident in applications where good wetting of the substrate is required (eg gluing, sealing, potting, laminating, etc.) or where a perfect leveling of the composition (casting flooring) is required.

Epoxy resins based on the reaction products of dian (i.e., 2,2-bis (p-hydroxyphenyl) propane) or novolac with epichlorohydrin, β-methylepichlorohydrin or glycerol-KjT-dichlorohydrin are used as the resin component of the compositions of the invention. The starting novolak is obtained by reaction

- 4 240 089 phenol or its derivatives (cresol, xylenol, etc.) with formaldehyde. Useful keto compounds should have at least one active hydrogen atom capable of addition reaction in the ¢ (-position), such as diacetone alcohol, cyclohexanone and derivatives thereof, such as methylcyclohexanone, 2---cyclohexenyl) cyclohexanone, etc. polyvalent phenols having a carbon number of 6 to 18, in particular phenol, cresol, xylenol, nonylphenol, resorcinol,

From hydroquinone and others. Other modifying compounds may also be alkyl, aralkyl, aryl and polyalkylether esters of unsaturated monocarboxylic and dicarboxylic acids having from 1 to 300 carbon atoms. These are primarily derivatives of acrylic, m-ethacrylic, maleic or fumaric acids, e.g. methyl, ethyl, propyl, butyl, 2-ethylhexyl and possibly other types of esters, the substituents of which can be extended by reaction with alkylene oxides up to 300 carbons.

Aliphatic and cycloaliphatic amines having carbon numbers of 2 to 18 and nitrogen atoms of 1 to 5 are used to prepare the specified hardeners, mainly diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine, cyclohexylaminopropylamine, and possibly others, and the second reactive component is aldehydes having 1 carbon atoms. to 7, in particular formaldehyde (in the form of an aqueous solution or as paraformaldehyde), acetaldehyde, benzaldehyde and the like. ratio of 0.8 to 1.2: 1.

The compositions of the invention find a wide range of applications in a wide variety of industries and other industries. Due to their properties, they are most often used as adhesives, sealants, casting and potting materials, casting flooring, plastic concrete, impregnating materials, contact resins for the production of laminates or other technical products, such as solvent-free paints, etc.

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240 069

Example 1

Palm type epoxy resin of mol. weight 380

Dian-type epoxy resin of mol. weight 900

Hardener prepared by reaction of dipropylene triamine with formaldehyde in mol. 1: 1 ratio

Xylenol

Resorcinol wt. parts

4 wt. parts by weight parts by weight parts 14 wt. parts

The mixture of ingredients (except hardener) is homogenized at 80 ° C for 30 minutes, then cooled to 20 ° C and a hardener is added.

The pot life of the composition thus prepared is 14 minutes at 20 ° C and 30 minutes at 5 ° C. The composition is suitable for bonding fireclay or basalt linings of cement kilns where it satisfies both bond strength and cure speed.

Example 2

Novolak type epoxy resin containing epoxy groups of 0.55 eq / 100 g

Curing agent based on the reaction product of cyclohexylaminopropylamine with formaldehyde in mol. Ratio: 1, 2

Dibutyl maleate

100 wt. parts by weight parts by weight parts

First, the resin / dibutyl maleate mixture was homogenized at 60 ° C for 30 minutes, then cooled to 20 ° C and a hardener was added.

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The pot life of the composition at 20 ° C is 120 minutes, the hard gel is formed after 24 hours. The composition is preferably cured for 2 hours at 120 ° C. It has excellent adhesive properties (shear strength 15 MPa, peeling 1.2 N / mm), mixed with metal powders, molybdenum disulphide or graphite is suitable as a sealant.

Example 3

Dian-type epoxy resin of mol. weight 400

The hardener based on the reaction product of triethylenetetramine with benzaldehyde in mol. ratio 1: 0.8

Kresol

Nonylphenol

Titanium dioxide

Powdered dolomite

00 wt. parts by weight parts

12.5 wt. 12,5 wt. parts by weight 60 wt. parts

The ingredients are homogenized with each other, the resulting composition cures at 120 ° C for 2 hours. It is suitable as a sealant with excellent anticorrosive effects.

Example 4

Dian-type epoxy resin of mol. weight 380

The hardener based on the reaction product of diethylenetriamine with paraformaldehyde in wt. ratio of components 103: 30

Ground feldspar

00 wt. parts by weight parts by weight parts

The composition has a pot life at 20 ° C of 45 minutes after hardening with a hardener, a hard, tough gel is formed in 90 minutes. It is suitable for bonding metals and wood.

- 7 Example 5

Dian-type epoxy resin of mol. weight 500

Hardener prepared by reaction of diethylenetriamine with formaldehyde in mol. 1: 1 ratio

Dibutyl maleate

Di (2-ethylhexyl) phthalate

Cyclohexanone

240 089

100 wt. parts by weight parts by weight parts 6.7 wt. 6.7 wt. part

The composition formed by mixing the components has a pot life at 20 ° C of 50 minutes, a hard and tough gel is formed after 24 hours. It is suitable for grouting and filling cracks in concrete or after addition of 27 masses. parts of kaolin and 27 wt. parts of ground feldspar such as casting flooring or plastic concrete.

Example 6

Dian-type epoxy resin of mol. weight 900

Hardener according to Example 5

Dioctyl phthalate

Dibutyl maleate

Xylenol

100 wt. parts by weight parts 10 wt. 25 wt. parts by weight parts

The pot life of the homogenized composition at 20 ° C is 60 minutes, curing takes place in 24 hours. When mixed with mineral fillers, the composition is suitable as a material for plastics.

Claims (1)

SUBJECT OF THE INVENTION 240 069 Curable epoxy compositions based on epoxy resins of the palm or novolak type, polyamine hardeners and optionally reactive modifying compounds, fillers, pigments and other additives, characterized in that they consist of 100 wt. parts of qpoxide resin of palm or novolak type of mol. weight 340 to 900, 5 to 50 wt. parts of curing agent based on reaction products of aldehydes of carbon number 1-7 aliphatic 'ne _r bo cycloaliphatic amines of the number of carbon atoms of 2 to 18 and nitrogen atoms 1 to 5 in mol. ratio 1; 0.8 to 1.2% and optionally up to 50 wt. ketone compounds having at least one active hydrogen atom capable of addition reactions, preferably diacetone alcohol, cyclohexanone, methylcyclohexanone, 2- (1-cyclohexenyl) cyclohexanone, alkyl-, aralkyl-, arylesters and polyalkyletheresters unsaturated monocarboxylic and dicarboxylic acids, preferably acrylic, methacrylic, maleic and fumaric acids, having a carbon number of 1 to 300 and phenols having a carbon number of 6 to 18, up to 300 wt. parts of pigments or fillers and up to 40 wt. parts of additives from the group of plasticizers, dyes, surfactants, fungicides, corrosion inhibitors and blowing agents.