DE3034536C2 - Polyamide-imide resin composition and its use - Google Patents

Description

The invention relates to polyamide-imide resin compositions.
Polyester type varnishes are now widely used as electrical insulating varnishes, particularly as varnishes for enameled wires, because they have balanced properties in terms of mechanical properties, electrical properties, heat resistance and the like.

The current trend towards miniaturization and weight saving of electrical equipments requires that enamelled wire enamels have good heat resistance and excellent abrasion resistance as well as having excellent resistance to freon. As paints for enamelled wires with good heat resistance, abrasion resistance and resistance to Freon are varnishes with high heat resistance, such as polyimide varnishes, polyamide-imide varnishes and the like, known. However, these paints have problems because they only work in special solvents such as N-methylpyrrolidone (NMP), are soluble because the resins themselves are expensive and the like. To ensure the heat resistance of To improve polyester lacquers for enamelled wires, so-called polyester-imide lacquers have already been proposed containing imide groups in some parts of the resin component. Polyester-imides are though improved in heat resistance as compared with polyesters, but have disadvantages in terms of heat resistance the heat softening properties, the resistance to freon and the abrasion resistance. Even in the case of tris (2-hydroxyethyl) isocyanurate modified polyester imides, in which one Improvement in heat softening properties has been sought, these products are in terms of the abrasion resistance and the resistance to freon are unsatisfactory and they are Polyamide imides not equivalent.

There are also various studies on the production of polyamide-imide varnishes with excellent heat resistance, which are soluble in general-purpose solvents such as cresol been. It has also been suggested many times as a reactive component a lactam or the like (see, for example, JP-AS 29 730/71, 30 718/74, 20 993/75 and 47 157/78). That practically preserved, in Creso! however, soluble lactam-modified polyamide-imide was in terms of heat resistance, in particular the breakdown temperature, considerably inferior to conventional polyamide-imides.

To improve heat softening properties, it may be possible to use a polyisocyanate with a To use isocyanurate ring as part of an isocyanate compound, but such a mass is improved in terms of heat softening properties, but considerably in terms of flexibility deteriorates, whereby no practical resin is obtained. For example, if the burn time becomes long, although the heat softening property is good, the flexibility is lowered. if on the other hand, the firing time is short, then the resin cannot be polymerized enough to produce a high molecular weight, and the heat softening property and flexibility become

therefore deteriorated.

A polyamide-imide resin has already been developed, which is made from a polyisocyanate with isocyanurate rings, an aromatic diisocyanate, a lactam and an acid anhydride is WGrden and that had good heat resistance and flexibility and was soluble in cresol. However, this was resin with problems in terms of machinability, since in the case of rapid firing there is insufficient polymerization that a high molecular weight and a high breakdown temperature could be obtained could be achieved. Furthermore, the flexibility was reduced The problem of fast workability could depend on the curing speed of the resin. Extensive research has now shown that the main reason for this is the slow cure rate was.

It is also known to be a phenolic resin Epoxy resin, a maleic resin or the like can be used as a curing agent for linear polyamide-imides. So z. B. the use of melamine resins is described in JP-OS 102 278/73. Even if a Melamine resin to an essentially linear polyamide-imide that is not a polyisocyanate with isocyanurate rings as a component is added, there will be no improvement in flexibility and the Get through temperature. Rather, there is even a tendency that these properties deteriorate with the result that the melamine resin is not used in practice.

It has been found that a polyamide-imide resin is considerably higher in heat resistance than the linear one Polyamide-imide can be obtained by including polyisocyanate units which are isocyanurate rings contained in the resin skeleton. Furthermore, curing agents (crosslinking agents) for the polyisocyanate, the Contains isocyanurate rings, investigated.

As a result, it was found that when special components according to the invention for polyamide-imide resins, which with polyisocyanate with isocyanurate rings and lactam had been modified, had significant effects, namely a prevention of Decrease in flexibility and breakdown temperature at the time of high-speed processing could be without deteriorating the flexibility and the breakdown temperature of the enameled wires became.

Polyamid-imide resins continue to be used as heat-resistant coating compositions for coating heat-resistant ones Cooking utensils, for the manufacture of internal parts of electronic devices, magnet wires and like used. However, since general-purpose polyamide-imide resins such. B. Hl-404, Hl-600 (trademarks for Hitachi Chemical Co., Ltd. products), only in N-methylpyrrolidone (NMP) and similar special Solvents are soluble, there are significant due to the use of expensive solvents Cost problems. A polyamide-imide with good heat resistance and impact resistance has already been developed which is soluble in cresol. Such a polyamide-imide resin can have good heat resistance and impact resistance as well as good appearance without blistering when the firing conditions should be properly selected, but this product is general purpose resins HI-404, HI-600, and the like inferior in the surface appearance of the coating film because a fine one on the surface Roughening and wrinkling takes place

This appears to be the basic problem of polyamide-imide resins, those with polyisocyanate with isocyanurate rings and modified with lactam and which are soluble in cresol. This is likely due to that due to the slow curing rate. Extensive investigations have now shown that the fine roughening of the surface and the formation of wrinkles on the surface can be improved by adding a metal salt of Sn, Mn, Co and / or Zn to the resin clogs.

The invention relates to a polyamide-imide resin composition, which consists of

(A) a polyamide-imide resin, produced by reacting a polyisocyanate or one contains several isocyanurate rings, one aromatic diisocyanate, one lactam and one Polycarboxylic acid containing at least one acid anhydride group in a solvent from Cresohyp, and

(B) at least one substance from the group

(1) alkoxy-modified amino resins,

(2) polyisocyanates that contain one or more isocyanurate rings,

(3) phenol / formaldehyde resins,

(4) epoxy resins,

(5) polyester resins containing one or more hydroxyl groups and which have been obtained using terephthalic acid and / or isophthalic acid as the acid component are and

(6) at least one metal salt of Sn, Mn, Co and / or Zn

and optionally other additives and curing catalysts.

The F i g. 1 bh 3 shows the relationship between the percentage of extraction and heating time, Figs at 25O ⁰ C.. 4 shows a schematic drawing of an apparatus for measuring the Durchsühlagstemperatur.

The polyisocyanate with one or more isocyanurate rings can be obtained, for example, by trimerizing a polyisonyanate compound. These The reaction can be carried out in a solvent which does not react with the isocyanate group. In order to effectively carry out the reaction, it is desirable to use a catalyst for trimerization of polyisocyanate compounds to be used. The product is a polyisocyanate that contains one or more Contains isocyanurate rings, the polyisocyanate being a non-masked material. any which are capable of dissolving the polyisocyanate compounds can be used. Examples for such solvents are aliphatic and aromatic hydrocarbons, halogenated aromatic Hydrocarbons, esters, ketones, ether, ethylene glycol monoalkyl monoacetates, Dimethyl sulfoxide and the like.

Examples of catalysts for the trimerization of polyisocyanate compounds are alkali metal acetates, Metal salts of iron, magnesium, nickel, zinc. Tin, lead, vanadium, titanium etc., organometallic Connections such as B. Titanium tetrabutoxide, N-methylmorpholine, 1.S-Diazabicyclo ^^. Ojundecen- /, Mannich bases of phenol, such as 2- (dimethylaminomethyl) -4,6-dimethylphenol etc., tertiary amines, such as N, N-bis (dimethylaminoethyl) -N-methylamine, 2-dimethylaminoether

nol etc., and organic carboxylates of tertiary amines.

The trimerization of the polyisocyanate compound can, for example, at a temperature from 0 to 160 ° C.

Trimerization of polyisocyanate compounds is very complicated in practice. It won't always selectively obtain an isocyanate adduct which contains only one isocyanurate ring in a molecule. Farther a mixture is also obtained, the unreacted polyisocyanate and isocyanate adducts with two or contains several isocyanurate rings in one molecule. According to the invention, such a mixture can also be used. The amount of the catalyst and the reaction temperature can vary depending on the number of Isocyanurate rings present in the isocyanate adducts are selected. If, for example, the reaction is carried out so that the proportion of remaining isocyanate groups is about 50%, then preferably 0.01 to 2% by weight of a tertiary Amine, based on the weight of the starting polyisocyanate, and a reaction temperature of 30 to 150 ° C used.

As a starting polyisocyanate for the production of the polyisocyanate, which has one or more isocyanurate rings contains any diisocyanate compounds which can form isocyanurate rings can be used namely, either aliphatic, alicyclic or aromatic diisocyanate compounds. If taking heat resistance, solubility, and production cost into consideration, then are preferred Examples of aromatic diisocyanates, such as. B. 4,4'-Diphenylmethandiisüc> uiiai, tolylene diisocyanate, Xylylene diisocyanate, 4,4'-diphenyl ether diisocyanate and the like. These connections can be either can be used alone or as a mixture of two or more.

The polyisocyanates that contain one or more isocyanurate rings can be used either on their own or as a * mixture of two or more. It <to it is also possible to use one or more polyisocyanates that have previously been synthesized, or one or more Polyisocyanates which contain one or more isocyanurate rings and which are blocked by blocking agents, such as. B. Phenol, cresol eto, after synthesis have been stabilized to change over time prevent use. The number of isocyanurate rings in the polyisocyanate with one or more Isocyanurate rings can be changed depending on the purpose, but the content is the residual isocyanate groups preferably in the range from 10 to 70% (if you consider the content of isocyanate grapper. insane Output DÜEoeyar.at applies as 100%). If the content is too high, then the heat resistance will be lowered, while on the other hand if the content is too low, the flexibility is reduced.

The amount of polyisocyanate with one or more isocyanurate rings that is used is for the purposes of the invention are very important. The same applies to the amount of the lactam described below. It is preferred, the polyisocyanate with one or more isocyanurate rings in an amount of 1 to 30 Equivalent%, based on the total isocyanate equivalent, to use. If the amount is outside of the stated range then none will be balanced Properties of heat resistance and flexibility are obtained. On the other hand, if the Quantities are too large, then during the synthesis, due to an increased degree of branching, a Gelation take place.

As lactams, which, like the polyisocyanates with one or more isocyanurate rings, are important Are starting materials for solubilizing the end product in a solvent of the cresol type, any materials can be used which are capable of having isocyanate groups and / or Acid anhydride groups react in a cresol type solvent, and those in the solvent are soluble. Examples of suitable lactams are ε-caprolactam, dodecyllactam, etc. These lactams can be used either alone or as a mixture. Among these is with regard to the Soluble wedge, the reactivity and the production cost ε-caprolactam preferred.

It is not necessary to add the lactam in an amount equivalent to the isocyanate group use (taking ε-caprolactam as bifunctional, i.e. .. 1 mole is 2 equivalents equivalent to). There is no guarantee that using a large amount of lactam will be effective Uptake of the lactam leads to the skeleton of the resin formed. The lactam is used in an amount of 20 up to 90 equivalent%, based on the total isocyanate equivalent, taking into account the heat resistance, flexibility and solubility. The lactam is essentially in the resin built-in. If the amount is out of the above-mentioned range, a polyamide-imide resin will not become obtained, which has balanced properties in terms of heat resistance and flexibility and which has excellent resistance to freon and abrasion effects

As aromatic diisocyanates, 4,4'-diphenylmethane diisocyanate 4,4'-diphenyl ether diisocyanate, Tolylene diisocyanate, xylylene diisocyanate, etc. can be used. These diisocyanates can either can be used alone or as a mixture of two or more.

Any desired carboxylic acids can be used as polycarboxylic acids which contain at least one acid anhydride group having an acid anhydride group which reacts with isocyanate groups and their derivatives are used become, such as B. Products of the following formulas:

ROOC- {- IJ

COOR

(Π)

Where R stands for hydrogen, alkyl, preferably with 1 to 8 carbon atoms, or phenyl and X stands for -CH ₂ -, -CO-, --SO ₂ - or -O-. An example of this is trimellitic anhydride etc. This

Polycarboxylic acids can be used either alone or as a mixture. If necessary, can a part of the polycarboxylic acid with at least one acid anhydride group by at least one carboxylic acid dianhydride, such as B.

Pyromellitic dianhydride,

Benzophenone tetracarboxylic acid dianhydride,

Butanetetracarboxylic dianhydride,

carboxylic acid dianhydride and its derivatives,

ίο

and / or by at least one aliphatic or aromatic dibasic acid, such as adipic acid, Sebacic acid, etc., can be replaced. Among these, taking into account the heat resistance and trimellitic anhydride is preferably used for production costs.

The amounts of the isocyanate component and the acid component used are preferably in Range of 1.5 to 0.7 / 1 in terms of the ratio of the carboxyl group and the acid anhydride group to the Isocyanate group. In particular, in order to obtain a high molecular weight resin, a ratio of about 1/1 most preferable.

The reaction for production of the desired polyamide-imide resin can be carried out in such a way that it feeds all the starting materials at the same time and the reaction at a temperature of about 160 performs to 23O ⁰ C. A preferred process for the prevention of haze is to enter all isocyanate components, the lactam and the solvent cresol type in a reactor, to leave the mixture at a temperature of 160-190 ⁰ C 1 implement hours to 3, the polycarboxylic acid having at least one To give acid anhydride group in the reactor and continue the reaction at a temperature of 200 to 230 ° C for 3 to 20 hours. The progress of the reaction can be followed by measuring carbon dioxide gas bubbles generated during the reaction and the viscosity of the reaction solution. In order to prevent changes with the lapse of time and to carry out the reaction uniformly, it is desirable to dissolve the isocyanate component in the cresol type solvent beforehand. To support the progress of the reaction, organometallic salts, e.g. B. tin octoate, zinc octoate, cobalt octoate, etc. and tertiary amines, as are conventionally used, can be used.

As the cresol type solvent, cresol, phenol, xylenol, etc. can be used. These solvents can be used either alone or as a mixture. As part of a solvent mixture can high-boiling aromatic organic solvents, such as. B. Xylene Nisseki Hisol-100 and 150 (Trademark for aromatic hydrocarbons made by Nippon Petrochemicals Co, Ltd.), Cellosolve acetate and the like can be used.

The polyamide-imide resin thus produced, which is soluble in a cresol type solvent, has excellent heat resistance and resistance to freon and abrasion. It has a pretty good flexibility when the resin is used alone. However, as mentioned above, the Curing speed is relatively slow, there is the disadvantage that it is compared with conventional Lacquers require a longer burning time (& h, the product has poor fast processing properties). It is therefore necessary to shorten the burning time; H. to make hardening faster. on the other hand Usually, when the burning speed is increased, there is a deterioration in appearance and a degradation in flexibility.

In order to avoid such undesirable phenomena, the specific component (B) is used as the curing agent according to the invention. The component (B) is used in an amount of preferably 1 to 300 parts by weight per 100 parts by weight of the component (A) used

As the alkoxy-modified amino resins (1), any product can be used, which by Implementation of an amino compound, e.g. B. of melamine, benzoguanamine, urea or the like, with formaldehyde or paraformaldehyde by addition condensation reaction and by alkoxylation of the resulting methylol group or groups with a Alcohol such as methanol, ethanol, propanol, butanol or the like have been produced. It can also Cocondensation polymers or mixtures thereof can be used. Although the reasons for this are not yet are clear, are alkoxy-modified benzoguanamine / formaldehyde resins, such as butylated benzoguanamine / Formaldehyde resin, effective.

The effect of adding the alkoxy-modified amino resin is considerable in the case of the polyamide-imide resin used according to the invention, which is soluble in cresol. However, this effect cannot be exhibited in the case of conventional polyamide-imide resins which are soluble in NMP type solvents. The blended amount of the alcohol-modified amino resin (1) in the polyamide-imide resin (A) varies according to the composition of the alkoxy-modified amino resin to be blended, the molecular weight and the functional groups of the resin. In general, it is set within the range in which no phase separation occurs and depending on the purpose. In the case of baking enamels for wire, it is more preferred to add the alkoxy-modified amino resin in an amount of about 1 to 20% by weight in terms of resin weight based on the weight (solid content) of the polyamide-imide resin. Any method can be used as the mixing method. For example, a solution of the alkoxy-modified amino resin is previously dissolved in cresol and the resulting mixture is added to the polyamide-imide resin. One can also proceed by one is to a directly heated dropwise polyamide imidharzlösung a solution of the alkoxy-modified amino resin is the temperature at the time of mixing is where no phase separation takes place and possible uniform mixing in the range of room temperature to 200 ⁰ C.

As polyisocyanates that contain one or more isocyanurate rings contain, (2) any substances can be used, which by trimerizing a Polyisocyanate compound are generated. For example, a trimer is obtained by converting a aromatic diisocyanates, especially tolylene diisocyanate, in the presence of a tertiary amine, or a mixture of the trimer and polyisocyanates, the contain one or more isocyanurate rings, preferably

The amount to be added of the polyisocyanate with one or more isocyanurate rings (2) as curing agent varies according to the polyfunctionality

of the polyisocyanate to be added. In the case of wire stoving enamels, however, it becomes more preferred, about 1 to 20% by weight, expressed as solids content, based on the weight (solids content) of the polyamide-imide resin. Products that were previously used with Phenol, cresol, ε-caprolactam and the like have been masked. As for the method of addition, can the polyisocyanate (2) may or may be added to the polyamide-imide resin at normal temperatures be added to a directly heated solution of the polyamide-imide resin. It is also possible to use the resin with another resin for stoving enamels for wires, e.g. B. a polyester resin, a polyester-imide resin, each to mix according to the intended use.

Phenol / formaldehyde resin (3) can be a phenol / Formaldehyde resin, an alkylphenol / formaldehyde resin, a modified phenol derived therefrom / Formaldehyde resin or the like can be used. As to the nature of these substances exist no restrictions. As modified phenol / formaldehyde resins, for. B. with amino compounds modified phenol / formaldehyde resins, such as phenol / formaldehyde resin modified with melamine, with benzoguanamine modified phenol / formaldehyde resin and the like can be used. The amino compound can also be the aforementioned alkoxy-modified amino resin.

The amount of the phenol / formaldehyde resin to be mixed varies depending on the molecular weight and the Type of functional groups contained therein. Usually it resides in that depending on the end use Area where no phase separation occurs. In the case of wire stoving enamels, it is more preferred to put it in an amount of about 1 to 30% by weight, expressed as resin weight based on weight (solids content) of the polyamide-imide resin. As for the mixing method, that will be added Phenol / formaldehyde resin is previously dissolved in cresol and the resulting mixture becomes the polyamide-imide resin given. You can also proceed in such a way that the phenol / formaldehyde resin is added dropwise a directly heated solution of the polyamide-imide resin

Epoxy resins from Bisphe-

nol type, novolak type epoxy resins, heterocyclic ring-containing epoxy resins, acyclic type etc. can be used. There are none as to the epoxy resins to be used special restrictions.

The amount of the epoxy resin to be mixed varies depending on its kind. Usually it is depending on the End use selected within the range in which no phase separation occurs. So it is z. B. in the case of stoving enamels for wires, it is more preferred to use it in an amount of about 1 to 30% by weight, expressed as Resin weight based on the weight of the polyamide-imide resin. As for the mixing method is concerned, the epoxy resin to be added is previously dissolved in cresol and the resulting mixture becomes given to the polyamide-imide resin, or one can also proceed in such a way that the epoxy resin is added dropwise to a directly heated solution of the polyamide-imide resin gives. To increase the viscosity with the lapse of time after the addition of the epoxy resin To avoid it, it is preferred, if possible, to add the epoxy resin immediately before use To give polyamide-imide resin.

It is also possible to use the polyester resin with one or more hydroxyl groups as the curing catalyst or hydroxyl residues obtained by using terephthalic acid and / or isophthalic acid as the acid component (5) has been obtained. In the production of such a polyester (5) are In such a case, terephthalic acid and / or isophthalic acid can be used as the acid component instead of terephthalic acid and isophthalic acid, for example, one or more lower alkyl esters of Terephthalic acid and isophthalic acid, such as dimethyl terephthalate, monomethyl terephthalate, diethyl terephthalate, Dimethyl isophthalate, diethyl isophthalate and the like, or one or more condensates of Terephthalic acid and / or isophthalic acid with a glycol, such as polyethylene terephthalate, polyethylene isophthalate etc., can be used.

Acids, which are generally used for electrical insulating varnishes, can be used as the acid component become, such as B. adipic acid, succinic acid, phthalic acid, trimellitic anhydride, imidodicarboxylic acids Formula:

HOOC- <O

N-R -N

C /

COOH

(IID

where R stands for a divalent organic radical, can also be used. The imidodicarboxylic acid of the formula III can be prepared by Reacts 1 mole of a diamine with about 2 moles of trimellitic anhydride, as is, for example, in JP-AS 40113/76 is described. As diamine can 4,4'-diaminodiphenylmethane, m-phenylenediamine,

p-phenylenediamine, 1,4-diaminonaphthalene, 4,4'-diaminodiphenyl ether, 4,4'-dimethylheptamethylenediamine, hexamethylenediamine, 4,4'-dicyclohexylmethanediamine, Diaminodiphenyl sulfone, etc. can be used. Naturally an imidodicarboxylic acid obtained using a diisocyanate can also be used

instead of a diamine

As an alcohol component for the production of the polyester with one or more hydroxyl groups (5) One or more polyhydric alcohols can be used. As dihydric alcohols can e.g. ethylene glycol diethylene glycol neopentyl glycol, 1,4-ButanedioI, 1,6-HexanedioL 1,4-Cyclohexanedimethanol etc. can be used. As three or more valued Alcohols can e.g. glycerine, trimethylolpropane, Tris (2-hydroxyethyl) isocyanurate, pentaerythritol eta be used. The use of tris (2-hydroxyethyl) isocyanurate is preferred in terms of heat resistance

The synthesis of the polyester with one or more hydroxyl groups (5) can be carried out with excess hydroxyl groups until an OH value of preferably 60 to 200 is reached. As a catalyst for the synthesis, conventionally used materials such as. B. lead oxide, lead acetate, tetrabutyl titanate, etc., can be used. There are no particular restrictions on these materials. The synthesis temperature is usually 150 to 300 ⁰ C.

When the polyester having one or more hydroxyl groups (5) with the polyamide-imide resin mixed, then it is mixed with a solvent commonly found in enamelled wire enamels is used, e.g. B. cresol, phenol, xylenol, N-methylpyrrolidone, Xylene, etc., dissolved in such a way that the content of non-volatile substances is 10 to 90% by weight. Of the Polyesters having one or more hydroxyl groups (5) may contain a curing agent usually found in Varnishes for enamelled wires are used, e.g. B. tetrabutyl titanate, tetraisopropyl titanate, zinc naphthenate, Cobalt octoate, block isocyanate (Desmodule-CT stable, manufactured by Japan Polyurethane Industries, Co.) or the like before being mixed with the polyamide-imide resin.

The temperature for mixing the polyester (5) with the polyamide-imide resin is usually subjected to room temperature to about 200 ⁰ C and is not particularly limited as long as uniform mixing is possible.

The amount of the polyester (5) to be mixed is not particularly limited but usually 1 to 300% by weight, more preferably 3 to 30% by weight, based on weight (Solid content) of the polyamide-imide resin.

In order to improve the roughening of the fine surface or the formation of wrinkles, at least one Metal salt of Sn, Mn, Co and Zn (6) is added to the polyamide-imide resin. Examples of such Metal salts are dibutyltin laurate, dibutyltin acetate, manganese naphthenate, manganese octoate, cobalt naphthenate, Cobalt octoate, zinc naphthenate, zinc octoate and the like. These substances are commonly used as a dryer. These metal salts can either stand alone or used as a mixture.

The metal salt (6) is preferably used in an amount of 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, per 100 parts by weight in terms of solid content of the polyamide-imide resin. The mixing of the metal salt (6) with the polyamide -imide resin can be carried out at room temperature up to about 200 ⁰ C and in this respect there are no special? Restrictions.

In addition to the above component (B), i. H. the alkoxy-modified amino resin (1), the Polyisocyanate with one or more isocyanurate rings (2), the phenol / formaldehyde resin (3), the Epoxy resin (4), the polyester resin with one or more hydroxyl groups, made using Terephthalic acid and / or isophthalic acid has been obtained as the acid component, (5) and the metal salt of Sn, Mn, Co and Zn, one or more others can be Additives such as other polyester resins as above mentioned, other melamine resins, as mentioned above, Polyether, polyamides, e.g. NyIon-6, nylon-6,6, nylon-12, Polyamide-imide, polyimide, polyhydantoin, guanidine carbonate, BenzotriazoL furan resin, phenoxy resin, rubbers, e.g. B. telechelic rubber with a average molecular weight of several thousand, natural rubber, acrylic rubber, acrylonitrile / Butadiene rubber, hydrin rubber, urethane rubbers, thioether rubber, butadiene rubber, are added to improve the properties. These additives can be used in an amount of 0.1 to 30% by weight, based on resin solids content.

Furthermore, as a curing catalyst to improve the properties, tertiary amines, such as Triethylamine, triethylenediamine, N-methylmorpholine, Ν, Ν-diethylethanolamine, dimethylaniline etc., organic Titanium compounds such as tetrabutyl titanate, tetrapropyl titanate, etc. can be used.

The polyamide-imide resin composition obtained in this way can be used, for example, as a lacquer by dilution with a polar solvent, e.g. B. an above-mentioned cresol type solvent, NMP, dimethylformamide, Dimethylacetamide or the like can be used at a resin content of 20 to 40% by weight. In In such a case, taking resin concentration and viscosity into consideration as co-solvents Xylene, an aromatic hydrocarbon mixture, cellosolve acetate and the like are used will.

The coating film made using such a varnish has good heat resistance, Resistance to fluorocarbons (resistance to the cooling medium), flexibility and against abrasion. It has improved rapid curing properties and an improved appearance. The product therefore has good industrial applicability. Furthermore, the polyamide-imide resin composition, containing the metal salt (6), a coating film having good heat resistance, Impact resistance and with an improved prevention of the fine surface roughening and the Result in wrinkling.

The polyamide-imide resin composition of the present invention having quick-setting properties that is in a solvent Soluble of the cresol type can mainly be used as a varnish for enamelled wires. she can but also as an impregnation varnish for electrical Insulations, cast lacquer, means for achieving a heat-resistant coating, as heat-resistant paint or heat-resistant varnish, as a heat-resistant film, as a heat-resistant adhesive, as heat-resistant lamination material, as a heat-resistant complex material together with glass fibers or carbon fibers or the like can be used.

The invention is illustrated in the examples, in which all parts and percentages are by weight., unless otherwise stated

Comparative example 1

(1) Synthesis of the trimer of
aromatic diisocyanate

Components g

Tolylene diisocyanate 600

Xylene 600

2-dimethylammoethanol (catalyst) 1.8

The above ingredients were transferred to a four-necked flask fitted with a thermometer

and a stirrer was provided. The mixture was ^{heated to 140 °} C. in a stream of nitrogen. The reaction was carried out at this temperature until the isocyanate group content was 25% (the initial concentration was 48%). The resulting product showed the absorption of ^{the isocyanate ring at 1710 and 1410 cm -1} and the absorption of the isocyanate group at 2260 cm -1 in the infrared spectrum.

(2) Synthesis of one soluble in cresol
Polyamide-imide resin G 37.0 equivalent to
relationship Components 113.3 0.11 Diisocyanate trimers,
synthesized under (1)
(50% solution) 96.0 0.91 4,4-diphenylmethane
diisocyanate 36.6 1.00 Trimellitic anhydride 300 0.65 ε-caproiactam Cresol

The above ingredients, with the exception of the trimellitic anhydride, were placed in a four-necked flask equipped with a thermometer, a stirrer and a tube for fractional distillation. It was heated to 180 ° C. under nitrogen to carry out the reaction at that temperature for 90 minutes. Thereafter, trimellitic anhydride was added to the flask and the temperature was raised to 210 ° C. The reaction was carried out at 21O ⁰ C h 15 °. The resin concentration was adjusted to 30% with cresol to give a varnish. The paint had a viscosity of 250 poises. The infrared spectrum of the resin showed the absorption of the imide group at 1780 cm ^-1 and the absorption of the amide group at 1650 cm -1.

Comparative example 2

(1) Synthesis of butylated benzoguanamine / formaldehyde resin

Components

Mole

! 0 men until the temperature in the reaction system was increased to 130 ° C. Was increased as the temperature to 130 ⁰ C, the removal of the butanol was discontinued and the flask was cooled when the temperature at 50 ⁰ C was dropped, the reaction mixture was a mixed solvent of butanol / xylene (1/1 weight ratio) diluted to give a resin solution having a solid content of 55% was obtained.

(2) production of a polyamide-imide resin composition,

which contains butylated benzoguanamine / formaldehyde resin

To previously heated (100 ⁰ C) of NMP solvent row polyamide-imide resin was synthesized in the above (1) solution to the butylated benzoguanamine / formaldehyde resin with stirring in an amount of · 5 parts, expressed as solids content per 100 parts HI -404 in terms of solid content, whereby a uniform resin solution was obtained.

example 1

The polyamide-imide resin used in Comparative Example 1

(2) was synthesized to about 80 ° C

heated and with the in comparative example 2 (1)

synthesized solution of butylated benzoguanamine /

Formaldehyde resin in an amount of 3 parts,

expressed as solids content, per 100 parts of polyamide

imide resin, expressed as solids content, added,

whereby a uniform polyamide-imide resin composition

was obtained.

Example 2

The polyamide-imide resin synthesized in Comparative Example 1 (2) was heated to about 150 ° C and with the butylated benzoguanamine / formaldehyde resin solution synthesized in Comparative Example 2 (1) in an amount of 5 parts in terms of solid content per 100 parts of polyamide-imide resin, in terms of solid content, was added, whereby a uniform polyamide-imide resin composition was obtained.

Example 3

(1) Synthesis of butylated benzoguanamine / formaldehyde resin

35

40

45

Ingredients Mol

50

Benzoguanamine

Paraformaldehyde (purity 80%)
Isobutyl alcohol

The above ingredients were placed in a 300 ml three-necked flask fitted with a thermometer, a condenser with a receptacle for the quantitative determination of the water and a stirrer. The. Temperature was raised to 100 ⁰ C at a rate of 5 ° C per min under stirring and the reaction was conducted for one hour at this temperature for 1 After 50 mg of phthalic anhydride were added to the flask and the temperature was raised to 110 ⁰ C. While maintaining the temperature at HO ⁰ C, the dehydration was carried out under reflux. At the time of the completion of the dehydration reaction, the butanol was taken out of the system.

37.4 0.2 Benzoguanamine 22.4 0.12 30th 0.8 melamine 10.1 0.08 118.4 1.6 Paraformaldehyde (purity 80%) 36.0 0.96 "Isobutyl alcohol 118.4 1.6 inn-mi-

The constituents mentioned were reacted with one another as in Comparative Example 2 (1). That resulting resin was diluted with a mixed solvent of butanol / xylene (weight ratio 1/1), whereby a resin solution with a solids content of 55% was obtained.

(2) production of a polyamide-imide resin composition,

which contains butylated benzoguanamine / formaldehyde resin

A polyamide-imide resin composition was prepared in the same manner as described in Example 2, with the

Exception that the above under (1) synthesized butylated benzoguanamine / formaldehyde resin in a An amount of 8 parts in terms of solid content was added.

The resin masses (lacquers) obtained in this way were coated onto wires, enamelled (or insulated) To get wires. The properties were tested and are summarized in Table I.

In all examples the enameled wires were made under the following conditions:

Vertical furnace with a height of 4.5 m

10

Oven temperature

Inlet / middle / outlet = 300 ° C / 350 ° C / 400 ° C (in Comparative Examples 2 and 3 280 ° C / 300 ° C /

320 ⁰ C)
Wire diameter:

1 mm, finished with a kind
Pulling speed:

according to Tables 1, II and III

The properties were tested according to JIS standard C 3003. A load of 2 kg was used at break-through temperature

Table I.

Sample (example no.)

Comparative example 1

Polyamide imide resin

Comparative example 2

example 1

Example 2 Example 3

Draw speed - 7.5 9 10 12 10 12 7.5 9 7.5 9 7.5

speed (m / min)

properties

Breakthrough temperature- 370 310 391 390

temperature ( ⁰ C) (load 2 kg)

Flexibility (around-good many good good

winding around the crack

Diameter)

Abrasion resistance 102 50 202 181 45 52 101 88 92 88 90 94

(times) (load 600 g)

Surface condition

371 370 365 372 368 360 362 Cracks Cracks good good good good good good

good bubbles good bubbles good bubbles good good good good good good

As shown using HI-404 and Comparative Example 2, when an alkoxy-modified Amino resin to a conventionally used basically linear polyamide-imide resin the breakdown temperature, flexibility and abrasion resistance are significant decreased when these wires are drawn at a standard drawing speed of 10 m / min. Of the The surface condition of the wires is not improved when drawn at a drawing speed of 12 m / min.

On the other hand, when, as shown in Comparative Example 1 and Examples 1 to 3, an alkoxy-modified one Amino resin is added to a polyamide-imide resin, which with a polyisocyanate, the one or contains more than one isocyanurate ring, and one lactam has been modified, then none will Reduction in breakdown temperature, flexibility and abrasion resistance for wires made with pulled at a standard speed of 7.5 m / min. Furthermore, in the case of wires, which have been drawn at a high drawing speed of 9 m / min (high-speed machining), almost no lowering of the breakdown temperature, flexibility and abrasion resistance observed and the surface condition is greatly improved.

The above results show that when an alkoxy-modified amino resin is added to the polyamide-imide resin, modified with a polyisocyanate with one or more isocyanurate rings and a lactam has been, no lowering of the breakdown temperature, flexibility, abrasion resistance and the like, and that the high-speed processability is greatly improved can be.

Such an outstanding effect cannot only be achieved by a combination of a conventional polyamide-imide resin with an alkoxy-modified amino resin. The polyamide-imide resin composition of the present invention therefore has a very important technical meaning.

Comparative example 3

Synthesis of one soluble in cresol
Polyamide-imide resin

Components G 33.3 equivalent to relationship Diisocyanate trimers, im 0.10 Comparative Example 1 (1) syn 113.3 thetized (50% solution) 4,4'-diphenylmethane 96.0 0.91 diisocyanate 36.6 Trimellitic anhydride 300 1.00 ε-caprolactam 0.65 Cresol

The above ingredients, with the exception of the trimellitic anhydride, were placed in a four-necked flask, the one with a thermometer, a stirrer and

230 214/642

a tube for fractional distillation was provided. The mixture was ^{heated to 180 °} C. under a stream of nitrogen to carry out the reaction at this temperature for 90 minutes. Thereafter, trimellitic anhydride was added to the flask and the temperature was raised to 21O ⁰ C

The reaction was conducted for one hour at 210 ⁰ C 15 The resin concentration was adjusted to 30% with cresol thereby obtaining a varnish. The paint had a viscosity of 250 poises. The infrared spectra of the resin showed the absorption of the imide group at 1780 cm- ¹ and the absorption of the amide group at 1650 cm- ¹ . When using the varnish for firing enamelled wires, this was adjusted with cresol so that the solids content was 30%.

Example 4

The synthesized in Comparative Example 3 polyamideimide resin was heated to about 100 ⁰ C. For this purpose, the polyisocyanate with isocyanurate rings (diisocyanate

Table II

trimer) synthesized in Comparative Example 1 (1) in an amount of 3 parts given as solids content per 100 parts of polyamide-imide resin, expressed as solids content with stirring, whereby a uniform polyamide-imide resin composition having a solid content of 30% was obtained.

B e i s ρ i e 1 5

That in Comparative Example 1 (1) synthesized polyisocyanate with one or more isocyanurate rings was dissolved in previously heated to 120 ⁰ C cresol and reacted, the resulting solution was added to the synthesized in Comparative Example 3 Polyamide-imide resin in an amount of 8 parts, expressed as solids content, per 100 parts of polyamide-imide resin in terms of solid content, whereby a uniform polyamide-imide resin composition having a solid content of 30% was obtained.

The resin compositions (paints) obtained in this way were coated onto wires. The properties were tested and are summarized in Table II

Sample (Example No.) Comparative Example 3

Example 4 Example 5

Pulling speed (m / min) 7.5

properties
Breakdown temperature ( ⁰ C) (load 2 kg)

Flexibility (wrapping around the
Diameter)

Abrasion resistance (times) (load 600 g)
Surface condition

Comparative Example 3 and Examples 4 and 5 show that when a polyisocyanate is added with a or more isocyanurate rings to a polyamide-imide resin, which with a polyisocyanate with one or

several isocyanurate rings and a lactam modified

has been adorned, no degradation of the breakdown components temperature, flexibility, abrasion resistance

Wires is observed, which with a standard drawing

speed of 7.5 m / min. It is also shown that in wires with high Drawing speed of 9 m / min (high speed machining) have been drawn, almost none Lowering of the breakdown temperature, flexibility and abrasion resistance occurs and that the Surface condition has been significantly improved.

The above results show that when a polyisocyanate having one or more isocyanurate rings is added to the polyamide-imide resin, which with a polyisocyanate with one or more isocyanurate rings and has been modified with a lactam, no lowering of the breakdown temperature, the flexibility, abrasion resistance and the like. Furthermore, the high-speed workability can be significantly improved. Thus, the polyamide-imide resin composition has to be dissolved in a solvent of the cresol type is soluble, a very important technical importance according to the invention.

7.5

7.5

370 310 370 372 370 367 Well many cracks Well Well Well Well 102 50 110 95 104 100 Well blow Well Well Well Well

Comparative example 4

(1) Synthesis of one soluble in cresol
Polyamide-imide resin

Equivalent ratio

Diisocyanate trimers, im
Comparative example 1 (1) synthesized (50% solution)

4,4'-diphenylmethane diisocyanate

Trimellitic anhydride

ε-caproiactam

Cresol 33.3

113.3

0.10

0.91

96.0 1.00 36.6 0.65 340

The above ingredients except for trimellitic anhydride were placed in a four-necked flask equipped with a thermometer, a stirrer and a tube for fractional distillation. The mixture was ^{heated to 180 °} C. in a stream of nitrogen in order to carry out the reaction at this temperature for 90 minutes. Thereafter, trimellitic anhydride was added to the flask and the

Temperature was raised to 210 ° C The reaction was stirred for 15 h at 210 ⁰ C performed the resin concentration was adjusted with cresol to 30%, thereby obtaining a varnish. The paint had a viscosity of 250 poises. The infrared spectrum of the resin showed the absorption of the imide group at 1780 cm ^-1 and the absorption of the amide group at 1650 cm -1.

(2) Synthesis of the phenol / formaldehyde resin

10

Components

Equivalent ratio

Cresylic acid

Formaldehyde (37% aqueous solution)

Triethanolamine

425
303

1.17
1.00

The above ingredients were placed in a four-necked flask equipped with a thermometer, a stirrer and a reflux condenser. The mixture was refluxed with stirring at 98 ° C for 90 minutes. Thereafter, the reflux condenser was removed and the reaction was carried out under reduced pressure of 30 to 50 mm Hg at 50 ³ C for 5 hours. Then the resulting resin was mixed with 450 g of cresylic acid diluted to give a phenol / formaldehyde resin solution.

Example 6

The synthesized in Comparative Example 4 (1) polyamide-imide resin was heated to about 100 ⁰ C. To this, the phenol / formaldehyde resin synthesized in Comparative Example 4 (2) was added in an amount of 3 parts in terms of solid content with stirring per 100 parts of polyamide-imide resin in terms of solid content, whereby a uniform polyamide-imide resin composition was obtained.

each film-coated plate were about 1 g of the coated film peeled off in a fitted with a condenser flask and 50 g of cresol immersed was then 5 h at 100 ⁰ C, a heat treatment carried out after the Se treatment, the solution with a glass filter (3G 2) filtered and it was washed with methanol. The filtration residue (undissolved material) was dried in a dryer with reduced pressure for 8 hours at 100 ^° C. and weighed in order to determine the percentage extraction. The results obtained are shown in FIG. 1 compiled

From Fig. 1 it can be seen that the percentage extraction of Examples 6 and 7 compared to that Comparative Example 4 (1) was decreased in a short period of time. This means that the addition from phenol / formaldehyde resin to the polyamide-imide resin to the polyamide-imide resin compound quick curing properties The polyamideimide resin composition according to the invention therefore has in technical fields where high speed machinability is required is a great technical asset

Example 8

That in the Ve; jleichsbeispiel 4 (1) synthesized polyamide in.idharz was heated to about 8O ⁰ C and with an epoxy resin in an amount of 5 parts in terms of solid content, per 100 parts of polyamide-imide resin in terms of solid content was added with stirring to form a uniform polyamide -imide resin composition was obtained.

Example 9

The synthesized in Comparative Example 4 (1) polyamide-imide resin was heated to 100 ⁰ C. To this, an epoxy resin was added in an amount of 15 parts in terms of solid content per 100 parts of polyamide-imide resin in terms of solid content with stirring, whereby a uniform polyamide-imide resin composition was obtained.

Example 7

The polyamide-imide resin synthesized in Comparative Example 4 (1) was heated to 80 ° C. and for this purpose was the phenol / formaldehyde resin synthesized in Comparative Example 4 (2) in an amount of 8 parts, expressed as the solids content, per 100 parts of polyamide-imide resin, in terms of solid content, added with stirring, thereby forming a uniform polyamide-imide resin composition was obtained.

55

Film formation method and extraction method

The polyamide-imide resin compositions (paints) of Comparative Example 4 (1) and Examples 6 and 7 were so adjusted that their non-volatile content 30% and they were applied to steel plates previously bonded and polished with sandpaper (400 CW) (Thickness 0.8 mm) stacked to a thickness of 0.30 mm. The coated sheets were in a Hot air .ftbbsofen with 25 ^. "Given u ^ d they were Dried and baked for 15 minutes, 30 minutes and 45 minutes, respectively, to obtain film-coated panels. from

60

Example 10

That in Comparative Example 4 (1) synthesized polyamide-imide resin was heated to 100 ⁰ C and with a novolak type epoxy resin in an amount of 10 parts, ausgedi * 'kt as a solid content, per 100 parts of polyamide-imide resin, expressed as solids content, under Stirring was added, whereby a uniform polyamide-imide resin composition was obtained.

Example 11

The synthesized in Vergieichsbeispiei 4 (1) polyamide-imide resin was heated to 8O ⁰ C. To this, an alicyclic type epoxy resin was added in an amount of 5 parts in terms of solid content per 100 parts of polyamide-imide resin in terms of solid content with stirring, whereby a uniform polyamide-imide resin composition was obtained.

Film formation method and extraction method

The polyamide-imide resin compositions (paints) of Comparative Example 4 (1) and Examples 8 to 11 were adjusted to have a non-volatile content

Had ingredients of 30%. They were applied to steel plates (0.8 mm thick) previously bonded and polished with sandpaper (400 CW) to a thickness of 0.30 mm. The coated panels were placed in a Heißluftblasofen of 25O ⁰ C and they were 15 min 30 min 45 min or dried and fired. This gave panels coated with film. From each film-coated plate, about 1 g of the coated film was peeled off, placed in a flask equipped with a condenser, and immersed in 50 g of cresol. Thereafter, a 5-hour heat treatment at 100 ⁰ C was performed. After the treatment, the solution was filtered off with a glass filter (3G-2) and washed with methanol. The filtration residue (undissolved material) was ^{dried at 100 °} C. in a dryer with reduced pressure for 8 hours and weighed in order to determine the percentage extraction. The results are shown in FIG. 2 compiled.

The F i g. Figure 2 shows that the percentage extraction of Examples 8 to 11 compared to the Comparative Example 4 (1) is decreased in a short period of time. This means that the addition of epoxy resin to the Polyamide-imide resin imparts rapid curing properties to the polyamide-imide resin composition polyamide-imide resin composition of the present invention in fields where high-speed workability is required of great technical merit.

Comparative example 5

Synthesis of soluble in cresol
Polyamide-imide resin

Components

Equivalent ratio

Diisocyanate trimers, synthetic 30.0 0.09

tized in comparative example 1 (1)
(50% solution)

4,4-diphenylmethane 113.3 0.91

diisocyanate

Trimellitic anhydride 96.0 1.00

f-caprolactam 36.6 0.65

Cresol 300

30th

35

40

45

50

The above ingredients, with the exception of the trimelib suicanhydride, were placed in a neck bowl fitted with a thermometer, a stirrer and a tube for fractional distillation. The mixture was ^{heated to 180 °} C. in a stream of nitrogen in order to carry out the reaction at this temperature for 90 minutes. Trimellitic anhydride was then added to the flask and the temperature was increased to 210 ^° C. The reaction was ^{carried out at 210 °} C. for 15 hours. The resin concentration was adjusted to 30% with cresol, whereby a varnish was obtained. The paint had a viscosity of 250 poises. The infrared spectrum of the resin showed the absorption of the imide group at 1780 cm ^-1 and the absorption of the amide group at 1650 cm -1. When the lacquer was used for firing enamelled wires, it was adjusted with cresol so that the solids content became 30%.

Comparative example 6
Synthesis of the polyester

Components G Gram equi valent Dimethyl terephthalate 517.9 5.34 Tris- (2-hydroxyethyl) -iso- 381.6 4.38 cyanurate Ethylene glycol 100.5 3.24 Tetrabutyl titanate 1.0 (Catalyst) Cresol 176.5

The above ingredients were placed in a four-necked flask equipped with a thermometer, a stirrer and a tube for fractional distillation. The mixture was reacted at 180 to 220 ^° C. under a stream of nitrogen, whereby a resin with an OH number of 175 was obtained.

Cresol was added to the resin produced so that a varnish with a resin content of 30% was obtained became.

Comparative example 7

A polyester varnish made from terephthalic acid and glycerine and ethylene glycol was used.

Comparative example 8

A polyester varnish made from terephthalic acid, Imidodicarboxylic acid, tris (2-hydroxyethyl) isocyanurate, and ethylene glycol were used

Example 12

The polyamide-imide resin synthesized in Comparative Example 5 was heated to about 150 ^° C. and the polyester resin synthesized in Comparative Example 6 was added in an amount of 10 parts in terms of solids content per 100 parts of polyamide-imide resin in terms of solids content, with stirring, whereby a uniform Polyamide-imide resin composition was obtained.

Example 13

To the polyamide-imide resin synthesized in Comparative Example 5 in an amount of 100 parts, in terms of solids content, the polyester paint was of Comparative Example 7 in an amount of 10 parts in terms of solid content, whereby a uniform polyamide-imide resin composition was obtained.

Example 14

To the polyamide-imide resin synthesized in Comparative Example 5 in an amount of 100 parts, In terms of the solid content, the polyester paint of Comparative Example 8 was used in an amount of 5 Parts, expressed as solids content, given, whereby a uniform polyamide-imide resin composition was obtained. ■

In order to improve the quick setting properties by adding a polyester resin to the To show polyamide-imide resin, films were made from the

Paints of Comparative Example 5 and Examples 12 and 13 produced. From the paints of the comparative example 5 and Examples 12 and 14, enameled wires were formed with the burning times being varied. The percent extraction by cresol was measured on the films. With the enamelled wires the properties were measured in practice.

1) Film formation and extraction method
The polyamide-imide resin masses (lacquers) of the

Comparative Example 5 and Examples 12 and 13 were adjusted so that their non-volatile content would be 30%. They were applied to steel plates (0.8 mm thick) previously bonded and polished with sandpaper (400 CW) to a thickness of 0.30 mm. Each coated plate was placed in a Heißlufiblasofcn of 25O ⁰ C and 15 min 30 min 45 min or dried and fired, whereby film-coated

Table III

Plates were obtained. From each film-coated plate, about 1 g of coated film was peeled off, placed in a flask equipped with a condenser, and immersed in 50 g of cresol. A heat treatment was then carried out at 100 ^{° C. for 5 hours.}

After the treatment, the solution was filtered with a glass filter (3G-2) and washed with methanol. The filtration residue (undissolved material) was ^{dried at 100 °} C. in a dryer with reduced pressure for 8 hours and weighed in order to determine the percentage extraction. The results obtained are shown in FIG. 3 compiled.

2) Properties of the enameled wires

The properties of the enamelled wires obtained in the comparison example! 5 and in the example parts 12 and 14, were measured. They are summarized in Table III.

Sample (Example No.) \ Comparative example 5

Example 12 Example 14

Drawing speed im / min) 7.5 9 7.5 9 7.5 9

properties

Penetration temperature (C) (load 2 kg) 370 310 370 360 372 370

Flexibility (wrapping around the good many cracks good good good good Diameter)

Abrasion resistance (times) (load 600 g) 98 42 92 89 90 85

It can be seen from FIG. 3 that in the case of polyamide-imide resin which has been modified with a polyisocyanate having one or more isocyanurate rings and a lactam, a cresol extraction of 30% or less can only be obtained by running for 45 minutes or more 25O ⁰ C heated the other hand, in the case of Examples 12 and 13, in which polyester resins are added with one or more hydroxyl groups, obtained by using terephthalic acid and / or isophthalic acid as the acid component to the polyamide-imide resin, a Cresolextraktion of 30% or less can easily be obtained by heating to 250 ^° C. for only 15 min. This clearly shows that the addition of polyester resin with one or more hydroxyl groups, obtained using terephthalic acid and / or isophthalic acid as the acid component, improves the rapid curing properties of the polyamide-imide resin

As further shown in Table III, in Comparative Example 5, when the wire with a Pulling speed of 9 m / min is pulled, with a relatively short burning time the breakdown temperature, the flexibility and the abrasion resistance are considerably reduced, while in the case of Examples 12 and 14 almost no reduction in breakdown temperature, flexibility and abrasion resistance was observed. This also shows that the addition of polyester resin with one or more hydroxyl groups, obtained using terephthalic acid and / or isophthalic acid as the acid component, the Improved rapid curing properties of the polyamide-imide resin

The invention is therefore great in terms of improving the workability of polyamide-imide resins effective and it has a very important technical meaning.

Comparative example 9

Synthesis of one soluble in cresol
Polyamide-imide resin

Components

Equivalent ratio

Diisocyanate trimers, synthetic 407 0.10

tized in comparative example 1 (1)
(50% solution)

4,4'-diphenylmethane 1120 0.90

diisocyanate

Trimellitic anhydride 960 1.00

c-caprolactam 366 0.65

Cresol 3100

The above ingredients except for trimellitic anhydride were placed in a four-necked flask equipped with a thermometer, a stirrer and a tube for fractional distillation. The mixture was ^{heated to 180 °} C. under a stream of nitrogen to carry out the reaction at this temperature for 90 minutes. Then trimellitic anhydride was added to the flask,

and the temperature was increased to 210 ^° C. The reaction was carried out ^{at 210 ° C. for 15 hours.} The resin content was adjusted to 30% with cresol, whereby a varnish was obtained. The paint had one

Viscosity of 250 poises. The infrared spectrum of the resin showed the absorption of the imide group at 1780 cm ^-1 and the absorption of the amide group at 1650 cm -1.

Examples 15 to

To 100 parts, expressed as the solids content, polyamide-imide resin, which in Comparative Example 9 synthe- ι ο was tized, the individual metal salts listed in Table IV were added, creating a paint was obtained.

Table IV i-,

Example no. Metal salt

Zinc naphthenate
Cobalt octoate
Dibutyltin laurate
Manganese naphthenate

Quantity (parts)

2.0
0.5
0.5
1.0

20 After defoaming of the coatings of Comparative Example 9 and Examples 15 to 18, these paints were in a thickness of 0.325 mm on bonderized steel plate (thickness 0.775 mm), which had been polished with sand paper (400 CW), is applied. The individual coated panels were dried for 30 minutes at 25O ⁰ C fired, whereby film-coated plates were obtained.

For these film-coated panels, the breakdown temperature (as an index of heat resistance), the Erichsen test value (as an index for the flexibility) and the impact resistance (impact resistance test measured by the du Pont method). The appearance of the surface was visible to the naked eye rated.

The results are shown in Table V.

Table: V

Example no.
Comparative Example 9 Example 15 Example 16 Example 17 Example 18

Breakdown temperature * ') (C)
Erichsen test * ² ) (mm)

Impact strength (cm) (du Pont method, load 1 kg, core size
of the impact element 0.3 cm)

Appearance

370

70

35

fine roughening of the surface, wrinkling

371

70

35

370

370

72

35

no roughening of the surface and none
Wrinkling

" ¹ K breakdown temperature:

The film-coated plate was placed in the apparatus shown in Figure 4 to measure the breakdown temperature. In FIG. 4, the reference number 1 denotes a load (2 kg), the reference number 2 denotes metal support parts, and the reference number 4 the sample (film-coated plate with a thickness of 0.775 mm), reference number 4 the coated surface, the Reference number 5 a steel ball (diameter 5 mm), reference number 6 a sealing ring, reference number 7 a Steel plate (0.8 mm thick), numeral 8 an insulation plate (glass cloth), and numeral 9 an AC power source (100 V).

* ² ): Erichsen test according to JIS standard B 7777. The larger the values, the better the flexibility

From Table V it can be seen that the polyamide-imide resin, that modified with reaem polyisocyanate with one or more isocyanurate rings and a lactam and which is soluble in cresol has good heat resistance before being mixed with a metal salt (Breakdown temperature), good impact resistance, good flexibility (Erichsen test impact test) but has a bad appearance, i. h, a fine one Has surface roughening and wrinkling in the surface Examples 15 to 18, in which different types of metal salts according to Table V to the polyamide-imide resin were added, good results not only in terms of heat resistance, impact resistance and flexibility but also in terms of surface appearance. This clearly shows that the addition of special metal salts to the polyamide-imide resin improves the coated surface

The polyamide-imide resin composition of the present invention can therefore be applied to heat-resistant cooking utensils, magnet wires, etc. with good success.

For this purpose 4 sheets of drawings

Claims (8)

Patent claims: 1. Polyamide-imide resin composition, characterized in that it consists of (A) a polyamide-imide resin made by Reaction of a polyisocyanate with one or more isocyanurate rings, an aromatic one Diisocyanate, a lactam and a polycarboxylic acid having at least one acid anhydride group in a cresol type solvent, and (B) at least one substance from the group (1) an alkoxy modified amino resin, (2) a polyisocyanate with one or more isocyanurate rings, (3) a phenol / formaldehyde resin, (4) an epoxy resin, (5) a polyester resin having one or more hydroxyl groups obtained using of terephthalic acid and / or isophthalic acid as the acid component, and (6) at least one metal salt of Sn, Mn, Co and / or Zn and optionally other additives and curing catalysts. 2. polyamide-imide resin composition according to claim 1, characterized in that the polyisocyanate with one or more isocyanurate rings residual isocyanate groups in an amount of 10 to 70% contains. 3. polyamide-imide resin composition according to claim 1, characterized in that the lactam in one Amount of 20 to 90 equivalent percent, based on the total isocyanate equivalent, has been used. 4. polyamide-imide resin composition according to claim 1 or 2, characterized in that G is the polyisocyanate with one or more Isoeyanuratringen in an amount of 1 to 30 equivalent%, based on the Total isocyanate equivalent, has been used. 5. polyamide-imide resin composition according to claim 1, characterized in that as component (B) an alkoxy-modified amino resin in an amount of 1 to 20 parts by weight in terms of Solid content per 100 parts by weight in terms of solid content of the polyamide-imide resin is used has been. 6. polyamide-imide resin composition according to claim 1, characterized in that as component (B) a phenol / formaldehyde resin in an amount of 1 to 30 parts by weight in terms of solid content, used per 100 parts by weight in terms of solid content of the polyamide-imide resin has been. 7. polyamide-imide resin composition according to claim 1, characterized in that as component (B) an epoxy resin in an amount of 1 to 30 parts by weight in terms of solid content per 100 parts by weight in terms of solid content of the polyamide-imide resin was used. 8. polyamide-imide resin composition according to claim 1, characterized in that as component (B) a polyester resin having one or more hydroxyl groups obtained using terephthalic acid and / or isophthalic acid as the acid component, in an amount of 1 to 300 parts by weight in terms of solid content, per 100 parts by weight in terms of solid content of the polyamide-imide resin was used