DE1266982B - Process for the production of molded bodies or coatings on the basis of epoxy polyadducts - Google Patents

Description

III UNITED REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C08g

HOIb

German KL: 39 c - 30
/

Number: 1 266 982

File number: A 38589IV d / 39 c

Filing date: October 18, 1961

Opening day: April 25, 1968

When using epoxy compounds-carboxylic acid anhydride mixtures for impregnation and pouring purposes, e.g. B. for the impregnation of electrical Machines and apparatus, such as transformers, it is desirable that the mixtures have a low viscosity so that they penetrate properly into the object to be impregnated or poured can. For example, when impregnating coils for high-voltage electrical machines and of insulated high voltage conductors, it is of vital importance that the impregnation agent can penetrate completely into the insulation and fill all cavities occurring in it, so that the occurrence of glow phenomena is prevented.

In the production of polyadducts, it is known to use epoxy compounds with more than one epoxy group to react in the molecule with carboxylic acid anhydrides in the presence of additions of aliphatic alcohols.

According to the invention, it has surprisingly been found that the viscosity of the known mixtures of epoxy compounds and carboxylic acid anhydrides as well as those of the known mixtures of epoxy compounds and carboxylic acid anhydrides in the presence of additives when using special additives can be significantly lowered.

The invention relates to a process for the production of moldings or coatings on the Basis of polyadducts by reacting epoxy compounds with more than one epoxy group in the Molecule with carboxylic acid anhydrides in the presence of 2.5 to 60 percent by weight of additives on the sum of the weight of the carboxylic acid anhydrides and additives, which is characterized by that methyl isopropylphenols are used as additives.

As an example of methyl isopropylphenols that can be used, 3-methyl-6-isopropylphenol (thymol), 3-methyl-5-isopropylphenol (isothymol), 2-methyl-5-isopropylphenol (Karvakrol), 3-methyl-4-isopropylphenol, 2-methyl-6-isopropylphenol and 4-methyl-2-isopropylphenol to be named.

The methyl isopropyl phenols can either be used individually or as a mixture of at least two used by them.

It is particularly advantageous to prepare the starting mixture containing the epoxy compound in such a way that the carboxylic acid anhydride and methylisopropylphenol are first mixed before the mixture obtained is combined with the epoxy compound. The mixture of carboxylic acid anhydride and methyl Process for the production of moldings or coatings based on
Epoxy polyadducts

Applicant:

Allmänna Svenska Elektriska Aktiebolaget,

Västeräs (Sweden)

Representative:

Dipl.-Ing. H. Missling, patent attorney,

6300 Giessen, Bismarckstrasse. 43

Named as inventor:

Jostein Andreassen, Västeräs (Sweden)

Claimed priority:

Sweden of October 28, 1960 (10 360)

This is because isopropylphenol is liquid at room temperature, which is why heating is otherwise necessary of the carboxylic acid anhydride to bring it into molten form and its distribution in the epoxy compound to enable, avoids and thus also the risk that the anhydride and the epoxy compound react with each other and thereby shorten the service life.

The content of methyl isopropylphenol can be between 2.5 and 60 percent by weight, based on the The sum of the weight of the carboxylic acid anhydrides and the methylisopropylphenols varies, but it is usually undesirable to use excessive amounts of it. Calculated from the sum of Acid anhydride and methyl isopropylphenol, which, as said, preferably to a special mixture which is later added to the epoxy compound, the preferred content is methylisopropylphenol 5 to 30 percent by weight.

As the carboxylic acid anhydride, those known as reaction components for epoxy compounds can be used Acid anhydrides are used, phthalic anhydride, tetrahydrophthalic anhydride and hexahydrophthalic anhydride, either individually or as a mixture of at least two of them. When using a mixture of tetrahydrophthalic anhydride and hexahydrophthalic anhydride has proven advantageous to such proportions

809 540/473

the same to use that the content of the first mixture, which consisted of 76.5 parts of hexahydrophthalic acids 10 to 30, preferably 15 to 25, parts by weight of tetrahydrophthalic anhydride and 13.5 parts Percent, and the content of the latter is 70 to 90, and 10 parts of 3-methyl-6-isopropylphenol, preferably 75 to 85 weight percent mixing acid. The said mixture of acid anhydrides anhydride mixture is. 5 and 3-methyl-ö-isopropylphenol has a melting

Compared to known processes, in which a mi- point of -18 ° C. The resulting mixture of mixtures with the addition of benzyl alcohols, epoxy compounds, acid anhydrides and 3-methyl the invention brings about the addition 6-isopropylphenol has a viscosity of about 700 cP of methyl isopropylphenols the advantage that the and a storage time of several months. the molded articles produced therewith, e.g. B. electrical io implementation takes place under those given in Example 1 Coils, high heat resistance, good thermal conditions, see aging properties and a low di-.

have electrical dissipation factor. Example 5

The invention is shown below on the basis of a 100 parts of the same epoxy compound as in the extra of exemplary embodiments explained in more detail, in 15 game 1 with 110 parts one prepared in advance which the specified parts of the various substances mixture consisting of 76 parts of hexahydrophthalic acid parts by weight affect. anhydride, 19 parts of tetrahydrophthalic anhydride

_. -I _{consists of 1} ^and 5 parts of 3-methyl-6-isopropylphenol,

e 1 s ρ 1 e l l mixed. The mixture of acid anhydrides and

100 parts of a liquid epoxy compound, which in 20 3-methyl-6-isopropylphenol has a melting point known way from epichlorohydrin and 4,4'-dioxy of 9 ° C. The resulting mixture of epoxydverdiphenyl-dimethylmethane has been established and bond, acid anhydrides and 3-methyl-6-isopropyl, about 5.2 gram equivalents of epoxy groups per kilophenol has a low viscosity and long storage gram has, with 100 parts one in advance time and is given under the in example 1 from prepared mixture, which implemented from 90 parts of hexahydro 25 conditions, phthalic anhydride and 10 parts of 3-methyl-6-iso-. .

propylphenol, mixed. The mentioned Mi-Example 6

Schung of anhydride and 3-methyl-6-isopropylphenol 100 parts of the same epoxy compound as in

has a melting point of 10 ° C and is thus liquid Example 1 are made with 115 parts of one in advance at room temperature. The resulting mixture of 30 prepared mixture, which consists of 68 parts of hexahydro-epoxy compound, acid anhydride and 3-methylphthalic anhydride, 17 parts of tetrahydrophthal-6-isopropylphenol has a viscosity of about 700 cP acid anhydride and 15 parts of S-methyl-fi-isopropyl at 23 ° C and a storage time of several monophenol, mixed. The said mixture was ten at room temperature. The reaction of the acid anhydrides and 3-methyl-6-isopropylphenol mixture with shaping is by heating 35 has a melting point of -12 ° C. The obtained only at HO ⁰ C for 15 hours and then mixed with the epoxy compound is advantageously 140 ⁰ C made for 24 hours or by heating in the manner indicated in earlier examples directly to 180 ⁰ C for 5 hours. implemented.

The amounts of epoxy compound and acid anhydride Example 7

are preferably adjusted so that to 1 gram-40

equivalent epoxy group 1 to 1.3 gram molecules 100 parts of a liquid epoxy compound, which in

Acid anhydride can be used. known way from epichlorohydrin and 4,4'-dioxy-

_. . diphenyl-dimethylmethane has been produced and

Example 2 _about 4 gram equivalents of epoxy groups per KiIo-

A pre-made mixture of 45 grams methyl becomes 80 parts one in advance

Isopropylphenol and acid anhydride is prepared in a mixture of 72 parts of hexahydrophthalic example 1 and with the acidic anhydride contained therein, 4 parts of 3-methyl-6-isopropylphenol given components and their amounts prepared and mixed 4 parts of 3-methyl-5-isopropylphenol.

treated with the difference that instead of the mixture of acid anhydride and dialkylphenols 3-methyl-6-isopropylphenol 3-methyl-5-isopropylphe-50 has a melting point of -13 ° C. The received nol is used. The melting point of the mixture mixture of epoxy compound, acid anhydride of dialkylphenol and acid anhydride is in this and the phenols mentioned is in the in the earlier

Case 15 ° C. Implemented in the manner indicated in the examples.

Example 3 Example 8

A previously prepared mixture of methyl 100 parts of a liquid, in the manner described

isopropylphenol and acid anhydride or a modified epoxy compound, which is about 4.5 gram

adorned epoxy resin is in Example 1 has equivalent epoxy groups per kilogram,

in the same manner and with the components specified therein, with 90 parts of a prepared in advance nents and quantities of the same prepares and treats 60 mixture of 81 parts of hexahydrophthalic acid

with the difference that instead of 3-methyl-6-iso-anhydride, 6.3 parts of 3-methyl-5-isopropylphenol and

propylphenol 2-methyl-5-isopropylphenol uses 2.7 parts of 2-methyl-5-isopropylphenol mixed. the

will. The melting point for the mixture of the mixture obtained is that described earlier

hydride and 2-methyl-5-isopropylphenol is converted 13 ⁰ C. manner to form molded bodies.

^{Example4 Ö5 Example9}

100 parts of the same epoxy compound as in the case of 100 parts of the same epoxy compound as in the case

game! will be with 100 parts of a prepared in advance Example 1 will be with 100 parts of a prepared in advance

prepared mixture, consisting of 90 parts of hexahydrophthalic anhydride, 5 parts of 3-methyl-6-isopropylphenol and 5 parts of 3-methyl-5-isopropylphenol. This mix is used in the earlier described manner implemented to moldings.

Example 10

100 parts of the same epoxy compound as in Example 1 is mixed with 100 parts of one in advance prepared mixture of 76.5 parts of hexahydro- ίο phthalic anhydride, 13.5 parts of phthalic anhydride, 5 parts of 3-methyl-6-isopropylphenol and 5 parts of 3-methyl-5-isopropylphenol mixed. This specified The mixture is reacted in the manner indicated in Example 1.

Instead of, as indicated in the examples, a special mixture of methyl isopropylphenol and to prepare acid anhydride before adding this mixture to the epoxy compound the epoxy compound, methyl isopropylphenol and acid anhydride in a single step be mixed. Next, either the methyl isopropylphenol or acid anhydride can be used with the epoxy compound be mixed before the remainder of the component is added. In all of these cases goes however, lost the particular advantage that a particular heating of the acid anhydride in connection so that it is distributed in the epoxy compound is avoided.

Claims (1)

Claim: Process for the production of moldings or coatings based on polyadducts by reacting epoxy compounds with more than one epoxy group in the molecule Carboxylic anhydrides in the presence of 2.5 to 60 percent by weight of additives, based on the sum of the weight of the carboxylic acid anhydrides and additives, characterized in that that methyl isopropylphenols are used as additives. Considered publications:
German interpretative document No. 1 035 361. 809 540/473 4.68 © Bundesdruckerei Berlin