DE1595814C3 - Process for the production of internally plasticized epoxy resins - Google Patents

Description

containing the reaction products of epichlorohydrin with more than one carboxyl group in the molecule represent acidic esters obtained from dimerized fatty alcohol and dicarboxylic acids or their anhydrides have been manufactured. These glycidyl esters can be represented by the general formula

CH ₂ CH-CHj-O-C-R'-CO-F-O-C-R-CO-CH ₂ -CH CH ₂

\ / Il Il Il II · \ /

ο oo oo ο

are reproduced, in which F = a divalent radical of dimeric fatty alcohol, R, R '= divalent Mean alkylene, arylene or cycloalkylene radicals. For example, R or R 'can be a phenylene-1,2-, Phenylene-1,3-, phenylene-1,4-, oxyphenylene-1,4-, naphthylene, Cyclohexylene, cyclopentylene, tetrachlorophenylene, tetrabromophenylene, ethylene, butylene-1,4-, 1,4-hexylene or 1,6-hexylene radicals. R and R ' can be the same or different.

To prepare the glycidyl esters described above, 1 mole of the dimeric can first be used Fatty alcohol with 2MoI dicarboxylic acid or its Esterify anhydrides such as phthalic anhydride or hexahydrophthalic anhydride. Afterward the resulting ester is converted into the glycidic ester with epichlorohydrin, for example in the presence an ion exchanger.

Polyvalent carboxylic acid anhydrides are used as polyadduct formers. There come here for example in question

Hexahydrophthalic anhydride,

Tetrahydrophthalic anhydride,

Phthalic anhydride,

Methylcyclohexanedicarboxylic anhydride,

Dodecenyl succinic anhydride,

Pyromellitic anhydride,

Endomethylenetetrahydrophthalic anhydride,

Methylendomethylenetetrahydrophthalic acid

anhydride,
Tetrachlor and

Tetrabromophthalic anhydride,
Dichloromaleic anhydride,
Hexachloroendomethylenetetrahydrophthalic acid

anhydride.

30th

35

40

45

The amount of carboxylic anhydrides to be used must be so large that 0.6 to one epoxy group 1.2, preferably 0.8 to 0.9, carboxylic acid anhydride groups are omitted.

Furthermore, organic nitrogen compounds can be used as polyadduct formers, which contain at least 2 contain active hydrogen atoms bound to nitrogen in the molecule. It can also be organic Compounds are used that only form compounds under the reaction conditions that the meet the aforementioned requirements.

For the implementation according to the invention, primary or secondary amines come into question, which both aliphatic as well as cyclic structure, έ ^ ο The cyclic amines can contain both cycloaliphatic, aromatic and heterocyclic rings. Furthermore, such amines can be used which have different of the aforementioned rings. Of the Amino nitrogen in heterocyclic amines can also be part of the ring. With the mentioned Compounds can have the active hydrogen atoms on one or on different nitrogen atoms.

Examples of the primary and secondary amines mentioned are as follows:

Ethylamine, propylamine, butylamine,

Hexylamine, dodecylamine, benzylamine,

Ethylenediamine, propylenediamine,

Butylenediarnine, diethylenetriamine,

Triethylenetetramine, dimethylaminopropylamine,

Diethylaminopropylamine,

1,2- or 1,4-diaminocyclohexane;

1,2-diamino-4-ethylcyclohexane,

l, cyclohexyl-3,4-diaminocyclohexane,

Aniline, o, m, p-phenylenediamine, benzidine,

4,4'-diaminodiphenylmethane.

Condensates of aniline with formaldehyde can also be used.

It is also possible to use those amines for the reaction according to the invention that are further contain functional groups, such as

Ethanolamine, propanolamine,

N- (hydroxyethyl) -l, 2-diaminopropane,

N- (Hydroxypropy!) - m-phenylenediamine,

N- (4-hydroxybenzyi) ethylenediamine,

N- (4-hydroxybenzyl) -diethylenetriamine,

4,4'-diaminodiphenyl sulfide,

4,4'-diaminodiphenyl sulfone,

Dicyanoethylethylenediamine,

1,4-bis-fy-aminopropoxymethylJ-cyclohexane,

chlorinated benzidines,

4,4'-diamino-3,3'-dichlorodiphenylmethane,

4,4'-diamino-3,3'-dimethoxydiphenyimethane,

4,4'-diaminodiphenyl oxide.

The amount of amines to be used is such that for an epoxy group 0.6 to 1.2, in particular 0.8 to 1.0, reactive amino hydrogens are omitted.

In principle, all are suitable as catalysts for curing the modified glycidyl isocyanurate Lewis acids, which can also be used in the form of their complexes. As a Lewis acid comes in primarily boron trifluoride and its complexes with monoethanolamine, piperidine, trimethylamine, Hexamethylenetetramine, urea, pyridine or water, ethylene glycol, glycerine, benzyl alcohol, Triethylamine, dimethylbenzylamine, dilaurylamine, vinylpyrrolidone, caprolactam and others. Further Tin tetrachloride, titanium tetrachloride, antimony pentachloride and others come in as Lewis acids Consideration.

Another important group of suitable catalysts are phosphines and tertiary amines, such as, for example

Triphenylphosphine,
Tetraphenylphosphonium chloride,

Diisopropylamine, Ν, Ν-dimethylaniline, 2,4,6-tris (dimethylaminomethyl) phenol, triethanolamine borate,
Tetramethylammonium chloride, benzyltrimethylammonium hydroxide and

-chloride,
N-alkyl pyridinium salts.

In addition, alcoholates such as aluminum triisopropoxide, aluminum tributoxide, aluminum, Cobalt, copper or nickel compounds of acetoacetic ester or acetylacetone. Furthermore is suitable butyl titanate.

A compilation of those suitable for the method according to the invention. Connections, i.e. the Polyadduct formers and the catalysts can be found in the book by A. M. P a q u i η »Epoxy compounds and Epoxydharze ", published in 1960 by Springer-Verlag, in the chapter on" Hardening in practice ". Of course this reference is not intended to mean that only the curing agents mentioned in the book by P a q u i η are useful.

The actual conversion or curing of the reaction components to the internally plasticized epoxy resins takes place between 20 and 200 ^° C., in particular at elevated temperatures of 120 to 180 ^° C., for 1 to 20, in particular 2 to 8 hours. In most cases, the formation of the cured epoxy resin has ended after this time. However, it may be useful to keep molded bodies at higher temperatures, e.g. B. 150 to 200 ⁰ C to anneal.

In the production of the epoxy resins according to the invention, dyes or Fillers are also used, such as metal powder, quartz powder, glass powder, glass fibers, mica, Aluminum oxide, titanium oxide, zirconium oxide, ground dolomite or barium sulfate. Under certain circumstances it can It may be useful to use accelerators to shorten the curing time of the mixtures. It come z. B. tert. Amines, N-alkylpiperidines, 2,4,6-tris (dimethylaminomethyl) phenol or triphenylphosphine for this purpose. It can also be in some In some cases, it may be advantageous to add reactive thinners, such as phenyl glycidyl ether, to the mixtures before curing Add butyl glycidyl ether, octylene oxide, butylene glycol diglycidyl ether, Ν, Ν-diglycidylaniline or styrene oxide.

The epoxy resins prepared according to the invention can be used particularly advantageously as casting resins will. It is possible, for example, to enclose complicated fittings with them without the Hardening Cracking occurs on edges or grooves. The electrical properties of the invention Epoxy resins produced show no decrease compared to the excellent values obtained with carboxylic acid anhydrides cured moldings based on crystallized triglycidyl isocyanurate are measured. Compared with these, they have superior impact strength and flexural strength.

The epoxy resins produced according to the invention are suitable as moldings, adhesives and coatings. The uncured mixtures can be used as casting resins, fillers, adhesives, dissolved in solvents,

for impregnation or together with fillers as

Molding compounds are processed.

In the following examples, the Marten temperature, the impact strength, the deflection, the Flexural strength and the tracking resistance according to DIN 53 458, DIN 53 453, DIN 53 542 and DIN 53 480 has been measured.

example 1

Mixtures were prepared from 100 g each of triglycidyl isocyanurate (mixture of the high and low melting form, epoxy oxygen content 15.5%), varying amounts of hexahydrophthalic anhydride and a diglycidyl ester of a dimerized fatty acid with an epoxy oxygen content of 3.6%. These mixtures were melted and, after thorough mixing, poured into molded bodies measuring 1px 15x120mm. The curing was up. carried out at 160 ^° C. for 3 hours and at 200 ^° C. for 20 hours.

The results are given in Table I below. In the first columns are the quantities of the added hexahydrophthalic anhydride (HHPA) and the dimeric fatty acid glycidyl ester (DFGE). In the following columns the Marten temperature, the impact strength, the deflection, the flexural strength, reproduced. The tracking resistance was KA 3 c in all cases.

Tabel I. Martens impact By Bend HHPA DFGE temp. Tough bend firm speed speed "C kp mm kp / cm ² G G cm / cm ² 186 18 5.5 1020 145 15th 157 26 8th 1180 150 25th 136 29 12th 1290 155 35 Example 2

As described in the previous example, mixtures of triglycidyl isocyanurate (epoxy oxygen content 15.5%) and varying amounts of methylhexahydrophthalic anhydride (MHHPA) and a glycidyl ester (GEDF) of a technical dimerized fatty acid, about 80% of which consists of dimer and about 20%, were used % consisted of trimer components. The glycidyl ester had an epoxy oxygen content of 3.4%. From the mixtures moldings were cast and cured for 3 hours at 160 ° C and 20 hours at 200 ⁰ C.

In the following table II, the amounts of the anhydride added and of the are in the first columns Glycidyl ester shown. This is followed by the Marten temperature, the impact strength, the deflection and the flexural strength. The tracking resistance was KA 3 c in all cases.

Tabel!!

MHHPA GEDP

Martenstemp.

Impact resistant
speed

cm / cm ²

Deflection bending strength

mm kp / cm ²

15th
25th
35

185
161
141

16
23
26th

7th
10

1000 1020 1160

Claims (1)

Claim: Process for the production of internally plasticized epoxy resins by converting more as compounds containing an epoxy group in the molecule with conventional ones for polyadduct formation substances capable of epoxy compounds and / or for ring-opening polymerization of epoxy compounds known catalysts, characterized in that as Compounds containing more than one epoxy group in the molecule crystallized triglycidyl isocyanurate with a content of at least 14% of epoxy oxygen and glycidyl esters of dimerized Fatty acids and / or glycidyl ethers of dimerized fatty alcohols and / or reaction products of epichlorohydrin with more than one carboxyl group in the molecule containing acidic esters consisting of dimerized fatty alcohol and dicarboxylic acids or their anhydrides have been produced, and as Substances capable of forming polyadducts with epoxy compounds are polyvalent carboxylic acid anhydrides or organic nitrogen compounds which have at least 2 active nitrogen-bound compounds Containing hydrogen atoms in the molecule, used, with 0.6 to 1.2 carboxylic anhydride groups per epoxy group or 0.6 to 1.2 reactive amino hydrogens are omitted, and the reaction is carried out between 20 and 200 ° C The invention relates to a process for the production of internally plasticized epoxy resins Reaction of compounds containing more than one epoxy group in the molecule with conventional compounds for polyadduct formation substances capable of epoxy compounds and / or for ring-opening polymerization catalysts known from epoxy compounds. Hardened synthetic resins based on organic compounds containing more than one epoxy group in the molecule Connections often have a very high heat resistance. This property shows, for example crystallized triglycidyl isocyanurate after reaction with conventional polyadduct formers or Catalysts. On the other hand, these epoxy resins often leave the mechanical properties that are expressed in the impact strength and flexural strength, much to be desired. Your tendency to crack Changes in temperature make them unusable for various purposes. If you bed z. B. metal fittings with Grooves and edges in a casting made of crystallized triglycidyl isocyanurate and, for example, dicarboxylic acid anhydride one, more or less large cracks appear, especially when there is a change in temperature. the mechanical, in particular the elastic properties of such epoxy resins can be determined by adding of plasticizers. "External plasticizers" can be used for this purpose, but they do bring certain disadvantages. Better results are achieved with "internal plasticizers". One has however, found that adding a small amount of internal plasticizers resulted in a relatively large drop the heat resistance occurs, which is in an unfavorable proportion to the improvement achieved mechanical properties You buy only a small improvement in elastic properties with significant losses of thermal ι ο properties (see "Kunststoffe", 1965, pp. 80 to 82). The invention is based on the object of avoiding the deficiencies of the known plasticization and to find a method that produces a good one with relatively little loss of thermal properties It has been found that more than one Compounds containing epoxy groups in the molecule for the production of internally plasticized Epoxy resins crystallized triglycidyl isocyanurate with a content of at least 14% of epoxy oxygen and also glycidyl esters of dimerized fatty acids and / or glycidyl ethers of dimerized fatty alcohols and / or reaction products of epichlorohydrin with more than one carboxyl group in the molecule containing acidic esters, which are derived from dimerized fatty alcohol and dicarboxylic acids or their anhydrides have been produced, and as substances capable of polyadduct formation with epoxy compounds polyvalent carboxylic acid anhydrides or organic nitrogen compounds which have at least 2 active ones Nitrogen-bonded hydrogen atoms in the molecule are used, with 0.6 per epoxy group up to 1.2 carboxylic anhydride groups or 0.6 to 1.2 reactive amino hydrogens are omitted, and the Implementation between 20 and 200 ° C is carried out For the process according to the invention, crystallized triglycidyl isocyanurate is used which is known in the art Way is made. It must have an epoxy oxygen content of at least 14%. In general Technical mixtures of the high and low melting form of triglycidyl isocyanurate are used The glycidyl compounds to be used according to the invention are made from dimerized fatty acids. Gemisehe are called dimerized fatty acids understood by "polymerized" unsaturated fatty acids, which in addition to the predominant proportion of dimeric fatty acids, trimeric and monomeric and possibly some proportions of tetrameric fatty acids contain. In technical dimerized fatty acids, for. B. about 10 to 30% of trimer and about 5 to 10% of monomeric fatty acids should be included. The dimerized ones obtained on the basis of natural fats Fatty acids have an average number of about 36 carbon atoms. You are as Starting material for the glycidyl esters or glycidyl ethers to be used according to the invention from practical Particularly suitable for reasons. Glycidyl esters of dimerized fatty acids are used. You can z. B. produce by Reaction of the free dimerized fatty acids with an excess of epichlorohydrin in the presence of a Ion exchanger. Furthermore, glycidyl ethers of dimerized fatty alcohols are used for the process according to the invention used, which can be obtained by reacting these fatty alcohols with epichlorohydrin in a known manner can get. Finally, such glycidyl esters are used,