DE1494419B2 - USE OF POLYESTERIMIDE RESINS TO MANUFACTURE STOVE ENAMELS - Google Patents

Description

Amines, it is only possible to achieve stoving enamels, which are particularly also because of the built-in Imide bonds are characterized by very good electrical and mechanical properties. So it was found that the thermal shock resistance of paints with an amine and trimellitic acid content is higher than without these additives. In addition, the polyesterimide resins used in the present invention exhibit a much less tendency to crack than

or are present in the high molecular weight ester and on the other hand carboxyl groups including those bonded in an ester-like manner Shares viewed. Primary amino groups are calculated to be 2 equivalents.

The amines can be aliphatic or aromatic in nature and preferably contain two primary ones Amino groups on the aromatic nucleus; may be mentioned e.g. B. ethylenediamine, diethylenetriamine, propylenediamine, Penta- or hexamethylene diamine, phenylene

those resins that are made without the use of amines io diamine, benzidine, diaminodiphenylmethane, diamino

were manufactured. diphenylethane, diaminodiphenyl ether, transesterification

The reactions for the digestion can with products of ρ, ρ'-diphenylolpropane with ethyleneimine

Temperatures of e.g. 170 to 250 ° C or mixtures of such compounds. you will be

will. The transesterification is expediently carried out at Tem- expediently in an amount of 3 to 45, preferably

Temperatures above 180 ° C, preferably above 15, used from 5 to 40 equivalent percent.

200 ° C and below the decomposition point of the The high molecular weight esters can be uniform

Reaction participants made, whereby sol- products or mixed esters or ester mixtures be,

Form borrowed polyester resins. The transesterification can terephthalic acid esters are preferred. For the her-

However, this high molecular weight ester is also in a stage with mixtures of alcohols

and acids or with low molecular weight esters of 20 no protection is sought.

polyvalent alcohols and polybasic acids _. ., ",.,

Examples 1 to 6

200 g waste of high molecular weight terephthalic acid ethylene glycol ester be changing with

25 quantities of ethylene glycol and / or glycerine under protective gas and stirring to temperatures between Heated at 220 and 270 ° C until a resin that is clear in the cold is formed. After cooling to 150 ° C are varying amounts of trimellitic acid and

30 ρ, ρ'-diaminodiphenylmethane was added and the mass then maintained at a gradually up to 22O ⁰ C increasing temperature in vacuum of 20 to 30 torr, until the melting point of the resin is 60 to 90 ° C. The amount of reactants results from

or be carried out in such a way that initially transesterified with a mixture or one of the esters mentioned and the reaction product is then reacted with further alcohol or further acid.

Instead of the acids, ester-forming derivatives, such as their anhydrides or esters with one or more polyhydric alcohols can be used. Esters of the bis (ethylene glycol) maleate type are known as to consider dihydric alcohols.

Examples of polyhydric alcohols include: ethylene glycol, 1,2- or 1,3-propanediol, 1,3-butanediol, 2,2-dimethylpropanediol, ρ, ρ'-dihydroxydicyclohexylpropane, Glycerine, trimethylolethane or -propane,

Pentaerythritol, sorbitol, the adduct of 35 in the table below. 2 moles of ethylene oxide in ρ, ρ'-dihydroxydiphenylpropane,. . l ^ -Dimethylolcyclohexane or mixtures thereof. Wer- examples / and 8 the mixtures of trihydric alcohols with other alcohols used 200 g waste of high molecular weight terephthalate, so the proportion of trivalent acid ethylene glycol esters were under protective gas with Alcohols in this mixture preferably contain at least 40 varying amounts of trimellitic or maleic acid-10 Mole percent, e.g., 20 to 60 mole percent. The anhydride is heated to 200 to 250 ° C until The proportion of alcohols of even higher value is in the form of a stirrable melt; then became generally not more than 20 mole percent. the mixture of ethylene glycol and glycerin inner-suitable anhydride-forming polycarboxylic acids are added dropwise at 200 to 230 ° C. within 2 hours z. B. Malein-, Itacon-, Citracon-, Bernstein-, Phthal-, 45 and 30 minutes later below 180 ° C the 4,4'-di-trimellite- or mellophanic acid, benzene carboxylic acid aminodiphenyl methane added slowly. After the end mixtures, as they are in the oxidation of z. B. Charcoal of the addition was stirred at 210 to 230 ° C for so long with nitric acid, condensation products arise until the melting point of the clear, grindable resin of maleic acid with abietic acid, conjugated un- was 70 to 80 ° C. The amount of reaction partially saturated Fatty acids such as 9,11-linoleic acid or Eläo can be found in the following table. Stearic acid, maleic acid terpene adducts or gels The resins obtained are in phenol, cresol, mix such polycarboxylic acids. Three- or four- xylenol, dimethylformamide, dimethylsulfoxide, soluble Acids are preferred. borrowed. As electrical insulating varnishes, they are used under user-die polyhydric alcohols and at least the usual painting processes and the usual dibasic anhydride-forming carboxylic acids are 55 painting machines preferred in the form of their crescent_ generally used in an amount of 2 to each solution. The stoving temperatures were -30 Equivalent percent, preferably together in one gene at 350 to 450 ° C. The hardening can in itself Amount of 10 to 40 equivalent percent used in known manner, e.g. B. by adding 1 to 5% where, before adding the amine, preferably a super-titanium butylate or aluminum alcoholates, the shot of hydroxyl groups against _ the Car- 60 with keto-enol compounds, z. B. acetoacetic ester, staboxyl groups are mostly bilized by at least 5 equivalents or by stabilized diisocyanates percent is applied. The term »equivalent- accelerated. Those using the percent «is based on all of the coatings obtained in the inventive resins The same functional groups contained in the mix are characterized by excellent heat and heat pes based. As equivalent groups are 65 shock resistance, furthermore by one on the one hand Amino and alcohol groups of superior abrasion resistance and low elasticity Alcohols, including those that in ester-like loss on long aging at temperatures above Bond, e.g. B. as maleic acid monoethylene glycol ester 120 ° C.

5 Ethylene glycol Glycerin Trimellitic acid
or anhydride 6th Diaminodi-
- phenylmethane example High molecular weight
Terephthalic acid
glycol ester (G) (G) (G) Maleic acid. '
anhydride (G) (s) 37 28 50 (g) ' 50 1 200 43 28 80 : 80 2 200 43 28 127 ".. ' 100 3 200 37 - 64 60 4th 200 37 64 40 5 200 37 - 64 30th 6th 200 56 28 96 70 7th 200 56 28 - 60 8th 200 40

Claims (6)

1 2 diamines or trimellitic anhydride with claims: aromatic or aliphatic diamines and dihydric alcohols are produced. These resins 1. Use of polyesterimide resins, are produced on their own or in mixtures with the made by digestion of high molecular weight, 5 reaction products of terephthalic acid methyl-insoluble Tere- and / or isophthalic acid esters, esters with di- and trihydric alcohols used, preferably waste from these materials, which are initially characterized by a wire enamel on this basis _x . . ,. ... astonishingly high heat resistance and excellent a) with at least two, preferably three, _mechanical properties. ^We uf?, JÜ α ^ole " ^um | ^eestert ' ^dar ™ l ^mlt ίο On the other hand, it is known to use electrical insulating varnishes Anhydndbildenden Di-, Tn- and / or Tetra- _{to produce by first} monomeric terephthalic carboxylic acids partially esterified or acid dimethyl ester with trivalent or higher valence b) partially chain-esterified with the acids mentioned under a), alcohols and linear diamines, then implemented with the lengthening and possibly branching mentioned under a) Alcohols are transesterified or 15. This is followed by the further implementation c) isocyanates in one stage with mixtures of alcohols. In the reaction in the first stage, however, and the acids mentioned under a) or with ^{always a so-called f} osse amount of monohydric alcohol, low molecular weight esters of polyhydric * ™ ^d ^ ^m original monomeric esters are present, alcohols and polybasic acids or so, ^since p ^the terminals have no reactive groups that initially with a mixture or a ² ° Since the reaction with the alcohols the ester-called transesterification and reaction ^u _t ^{nd de "Ami? s in e"} f ^r ^ f ^{evel before} _T! ^ch § ^{eht '15} I ^d f tion product then given with another disadvantage that the linear diamines in place Alcohol or other acid has been reacted, ^{the three} " ^and higher alcohols preferably with react with the monomeric terephthalic acid ester, each wound with polyvalent amines, 25 due to undesired premature amide formation at least two primary amino groups can occur, so that the chain length is not sufficient hold, have been implemented, is obtained for production. In addition, due to the in that of stoving enamels, in particular electrical insulation polyester molecule still present monovalent alcohol lacquers. hol components the amount of the three- and higher- 2. Embodiment according to claim 1, characterized by 30 valent alcohols apparently not in order to indicate that the high molecular weight insoluble crosslinking of the polyester amides to guarantee tere- and / or isophthalic acid esters with contribute. Therefore, even isocyanates trivalent and other alcohols must also be used containing that have been implemented by a urethane ^mixtures: in which adequate crosslinking effect. The proportion of the trihydric alcohol is at least 35. These disadvantages are eliminated according to the invention. 10 mole percent, preferably 20 to 60 mole percent. Thereafter, polyesterimide resins are envisaged to be produced amounts to. by digesting high molecular weight, insoluble ones 3. Embodiment according to claim 1 or 2, terephthalic and / or Isophthalsäureestern, preferably Abdadurch in that the reaction with cases from these materials, the alcohol mixtures has been conducted initially _vorzugswe in 40 _{a) having at least two} _ ₅ i _S e trivalent where the alcohol component is transesterified at most 20 mol alcohols, then with di-, tri- and / or tetracarboxylic acids forming anhydride percent of an at least tetravalent alcohol AA tu t UA ■■ u 1 u- -j partially esterified or 4. Embodiment according to claims 1 to 3,, *. , " ., · characterized in that, during the reaction, the 45 ^b > ^{with the} acids mentioned a) are partially polyhydric alcohols and the at least two-esterified, then transesterified with the valent anhydride-forming carboxylic acids mentioned under a) in each case alcohols, in an amount of 2 to 30 equivalent percent and then each with polyvalent amines, the and preferably contain together in an amount of at least two primary amino groups, 10 to 40 equivalent percent have been used 50 have been converted to produce stoving. ■ "'··' ·. ' varnishes, especially electrical insulating varnishes, 5. Embodiment according to claims 1 to 4, apply. characterized in that before the addition of the Amine counteracts an excess of hydroxyl groups, polyester, especially terephthalic acid over the carboxyl groups of at least 5 equiv. 55 and / or isophthalic acid esters, as they are in particular valent percent was present. . incurred in fiber and film production, and 6. Embodiment according to claims 1 to 5, which are so high molecular weight that they are insoluble, characterized in that the amine is soluble in a high amount by chemical reaction Convert from 3 to 45, preferably from 5, to valuable products that can be used as stoving 40 Equivalent percentage has been used. '' 60 paints, especially electrical insulating paints, are sensible . can be evaluated. The from the invention stoving enamels produced by the resins used ■ '"... differ in their structural structure and thus . , 'also in their properties from those after It is known as stoving enamels, e.g. for. ', The 65 previous technique from the monomolecular starting insulation from current-carrying wires, lacquers to corresponding products made of fabrics. By use the combination of a two-stage transesterification with the condensation of pyromellite acid dianhydride with aromatic or aliphatic a subsequent reaction with polyvalent