DE2651226A1 - Aqueous POLYAMIDIMIDE DISPERSIONS - Google Patents

Description

BASF Aktiengesellschaft

Our reference: OZ 32 282 Ls / Br 6700 Ludwigshafen, November 8th 1976

Aqueous polyamide-imide dispersions

The present invention relates to aqueous polyamide-imide dispersions, Process for their production and their use.

It was known to produce polyamide-imides from trimellitic anhydride chloride and diamines (DAS 1 520 968). In this procedure Hydrochloric acid is formed in the course of the reaction, which is difficult to remove.

Another known process is the conversion of trimellitic anhydride with isocyanates (DT-OS 1 595 797). This must be done with the exclusion of water, as this is caused by the reaction of isocyanates with water amines are formed, which in turn can react with isocyanates to form polyureas, which are known to be bad have thermal properties. The use of polyamideimide solutions in organic solvents such as those produced by these processes are obtained, leads to a strong environmental impact in the wire enamelling,

It was also known that polyamide-imides from butanetetracarboxylic acid with organic diamines and with trimellitic anhydride in aqueous Preparing solutions (DOS 25 I9 673, DOS 25 42 866) “The water solubility was forced by the reaction of the free carboxyl groups with ammonia. The ammonia is burned in split off again and burned, producing nitrogen oxides that are dangerous for the environment.

The object of the present invention is to provide aqueous polyamide-imide dispersions to show the particularly favorable processing properties have, do not result in any pollution of the environment in their processing and have advantageous properties in their application to lead.

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The present invention relates to

aqueous polyamide-imide dispersions, which are characterized by that they

20 - 60 percent by weight of polyaraidide with a particle diameter of less than 5 / um as well

1 - 6 percent by weight of a water-thinnable protective colloid

and the polyamide-imide is a condensation product

(A) 35 - ^ 5 percent by weight of at least one aromatic diamine,

(B) 10 - 60 percent by weight of at least one aromatic tri

carboxylic anhydride or its derivatives,

(C) 5- ^ 5 percent by weight of hexane, pentane and / or butane tetra

carboxylic acid or its anhydrides and

(D) 0-20 percent by weight of an aromatic tetracarboxylic acid

or their derivatives,

as well as methods for preparing aqueous Polyamidimiddispersionen _s wherein the polyamideimide initially dry and then wet milled under Vert ^ ending of dispersing mills high local energy density.

Another method for making these aqueous polyamide-imide dispersions is that a solution of the polyamide-imide in a cyclic ether in water with the addition of protective colloid precipitated and the cyclic ether is removed.

The present invention also relates to the use of these aqueous polyamideimide dispersions as wire enamels and for

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Production of temperature-resistant impregnations and bonds.

With regard to the structural components for the inventive Polyamide-imides to be used in aqueous dispersions should be carried out as follows »

(A) Examples of aromatic diamines are p-phenylenediamine, m-phenylenediamine, benzidine or diamines the general formula

^X ~ C3 " ^NH 2" ^where

X is -CH ₂ -, -0-, -CO-, -S-, -SO ₂ - or -SO-,

ο such as 4,4'-diaminodiphenylmethane, 4,4 ^f -Diaminobenzophenon, 4,4'-and 4,4'-diaminodiphenylsulphone Diaminodiphenylather, -sulphoxyd or sulfide;

4,4'-diaminodipheny is particularly preferred as component (A) lmethane.

Component (A) is condensed into the polyamide-imide in an amount of 35-45, preferably 30-40 percent by weight.

(B) Aromatic tricarboxylic acid anhydrides or their derivatives (B) are, for example, suitable; Trimellitic anhydride, hemimellitic anhydride-3,4,3 ', diphenylmethane- _{tricarboxylic anhydride-3,3' 9} 4, diphenylketone-tricarboxylic anhydride-3i3 '»4, diphenylether-triarboxylic anhydride-3» 3' »4, diphenylsulfidtricarboxylic ^{anhydride-3,3!} "4, Diphenylsulfontricarbonsäureanhydrid-3,3 '" 4, and mixtures of these anhydrides "Esters and partial esters of these tricarboxylic acids are also suitable, e.g. Trimellitic acid tri, di, or monoglycol ester = Trimellitic anhydride is particularly preferred as component B. Component (B) is condensed in in an amount of 10-60, preferably 20-50 percent by weight.

(C) The aliphatic tetracarboxylic acids hexane, pentane and butane tetracarboxylic acid come into consideration as component (C). Preferred is 1,2,3,4-butanetetracarboxylic acid.

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Component (C) is 5-45, preferably 10-30, percent by weight condensed in the polyamide-imide.

(D) In addition, up to 20 percent by weight of an aromatic tetracarboxylic acid or its derivatives can be condensed into the polyamideimide be. Suitable aromatic tetracarboxylic acids are, for example, pyromellitic acid, 3,3 ·, 4,4'-benzophenone tetracarboxylic acid or 3 »3 ', 4,4'-diphenylsulphonetetracarboxylic acid.

The following can be said about the polyamide-imides to be used according to the invention: The production of polyamide-imides can be carried out by various processes. Best solved is the tri- and tetracarboxylic acids in polyhydric alcohols such as ethylene glycol, propylene glycol or triglycol, optionally in mixtures of glycols and water and / or N-methylpyrrolidone with heating to 60-100 ⁰ Co Thereafter, the diamine is added and the used Solvent distilled off while increasing the temperature up to 200-220 ^{0 C.} This increases the viscosity of the resulting resins, which is determined from time to time. The increase in the brittleness of the cooled resins is also checked by taking samples. If viscous resins are obtained that can be easily ground on cooling, the condensation is considered to have ended.

In addition to butane, pentane and hexane tetracarboxylic acids or their derivatives, up to 20 moles of other, preferably aromatic Use tetracarboxylic acids or their derivatives. They are added at the beginning of the reaction.

With diamines, too, you can use mixtures of 10 - 90 mol .- # of one or the other diamine work.

The weight ratios of the acids to diamine can be varied from 0.7-1 »2 to 1.2-1.0. Most cheaply achieved you get the desired viscosities if you work equimolar.

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The solvents used, such as glycols or water, are largely distilled off; if necessary, 1-10 SS are left Solvent in the resin to get better flow properties.

The polyamide-imides suitable for the preparation of the aqueous dispersions are polyamide-imide condensates with an inherent one Viscosity of <0.5 dl / g (measured as a 0.5 # solution in N-methylpyrrolidone at 30 ° C), preferably <0.3 Idl / gJ, either in polyhydric alcohols or in water with removal of the organic solvent. It was surprising that the resins produced on the one hand result in elastic coatings, on the other hand by mechanical comminution or by dissolving in cyclic ethers and cases in protective colloid containing Water can easily be converted into an aqueous dispersion by deducting the solvent »

The water-thinnable protective colloids can either be used before Grinding or added during grinding.

Suitable protective colloids are, for example, polyvinylpyrrolidones, Polyvinyl alcohols and copolymers of vinyl pyrrolidone and vinyl propionate and / or copolymers of vinyl pyrrolidone and acrylates in amounts of 1-6, preferably 3-5 percent by weight, based on the polyamide-imide in question.

The dispersions can be produced on the one hand by comminution the polyamide-imide condensate melt in the dry state to a particle size of £ 100, u by means of a Orphan or by spraying in the spray tower and then on mechanical mills, e.g. impact plate mill, Pin mill or similar done. This is followed by dispersion and wet grinding.

Wet milling can be carried out in mechanical dispersing devices, for example in ball mills, preferably in dispersing machines with grinding media with high local energy density, e.g. in agitator ball mills, sand mills, Netzsch mills, planetary ball mills

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mills, kettle mills and attritors are run. as Grinding media are preferably spherical grinding media made, for example, of glass, ceramic, hard abrasion-resistant Plastic (e.g. polyamide) can be and their diameter is between 0.2 to 8, preferably 0.4 to 5 now.

About 6 to 10 hours are necessary for grinding to the desired particle size. The grinding time depends on the brittleness depends on the polyamide-imide used.

A second method for making inventive Polyamidimide dispersions can be by way of dissolving the polyamidimide condensates in cyclic ethers, such as Tetrahydrofuran and / or dioxane and subsequent precipitation in water containing protective colloids. After that, that will Solvent distilled off. The dispersion particles are round and the maximum grain size is 5, u. For refinement of the dispersion particles, the dispersion can additionally be wet-milled.

Towards the end of the wet grinding process, leveling agents, antithixotropic agents and, if appropriate, other additives such as pigments, fillers, dyes and, if appropriate, catalysts can also be added. The inventive dispersions contain particles having diameters of less than 5, preferably less than ₅ To 0.05 to 1.5 at.

The following are suitable leveling agents which may also be used: 1-5 percent by weight, based on polyamideimide, N-methylpyrrolidone, Butyl glycol, triglycol, dimethylacetamide, dimethylformamide and similar.

As antithixotropic agents, 0.5-5 percent by weight can be used on polyamideimide, ethanolamine, diethanolamine or triethanolamine can be added.

Catalysts suitable for hardening are titanates or oxotitanium compounds, such as triethanolamine titanate, Oxotitanium oxalates, citrates, lactates, tartrates, salicylates,

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phthalates, formates and gluconates. These can be used in amounts of 0.1-5 parts by weight, based on solid resin will.

The dispersions prepared according to the invention have those described There are no disadvantages of organic or aqueous paint solutions. You save that for powder systems in general necessary additional equipment and are required for the order using conventional methods, such as spraying, Dipping, pouring, flooding, soaking, brushing or squeegeeing are suitable. Obtained with the dispersions prepared according to the invention high-quality, temperature-resistant wire enamelling, impregnation, Bondings, laminates, multilayer materials and prepregs. It was not foreseeable that the properties of Enameled wires, laminates, prepregs, impregnations and bonds made with the dispersions prepared according to the invention were obtained that at least achieve the properties of the coatings with solutions.

The parts and percentages mentioned in the examples are parts by weight and unless otherwise stated Weight percent.

Example 1;

184.3 parts of trimellitic anhydride, 95 parts of 4,4-diaminodiphenymethane, 0.4 part of manganese (II) acetate and 800 parts of glycol were placed in a 3-liter four-necked flask equipped with a stirrer, thermometer and separator brought in. The mixture was then heated with stirring. At a temperature of 90-100 ^° C., the mixture becomes clear. At a temperature of about 140 ° C. the diamide dicarboxylic acid precipitates. At about 180 ° C water distills off. After 3 hours at 195 to 200 ⁰ C, the melt is transparent.

730 parts of glycol are distilled off. The temperature is then cooled to about 150 ⁰ C. Then 237.6 parts

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4.4 * -Diamxnodiphenylmethan, 142.5 parts of butanetetracarboxylic acid and 50 parts of glycol fed. The water of reaction distills off at 180 to 190 ^{° C. over the course of 1 hour.} Thereafter, the temperature at 195 is - 200 ⁰ C increased and distilled off again 50 parts glycol. This produces a viscous resin with an inherent viscosity of 0.133 dl / g (measured as a 0.5 # strength solution in N-methylpyrrolidone at 30 ^° C.).

The product was then comminuted with an impact plate mill (n = 9000 rpm; M = 5 kg / h) to an average grain size of 20 μ. To prepare 1000 parts of finished dispersion, 300 parts of polyamideimide powder, 695 parts of water, 3 parts of a copolymer of vinylpyrrolidone-vinyl propionate, 1.5 parts of ethanolamine and 0.5 parts of a polyvinyl alcohol with a residual acetate content of 30 % were used in a Dyno laboratory mill grind to dispersion (10 passes, 10 kg / h). The maximum particle size was 3 _s 2, u.

The dispersion was used to coat copper wires in a wire enamelling machine with an oven length of 2.5 m at 500 ° C. (8 passes). It has a layer thickness of 30, and reached and the following magnet wire properties found.

Diameter increase (wire diameter: 0.08 mm) 60, u

Breakdown voltage 4.5 kV

Heat shock

300 ° C χ 1 hour 1 χ day ok

Pencil hardness 5H

Softening point 375 ° C

Wrapping curls around own diameter after $ 20 pre. _Q elongation

Example 2

In a 3 liter four-necked flask fitted with a stirrer, a thermometer and distillation tube was provided, 19 »2 parts of trimellitic anhydride, 2.9 parts of 4,4-diaminodiphenylmethane and 62 parts of glycol are added and the temperature is increased to 180 ° C. with stirring, with 38 parts Water and glycol distilled off. Then 33 »6 parts of trimellitic anhydride were added and 8.3 parts of isophthalic acid were added. The temperature

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was increased to 20O ⁰ C and distilled off 15 parts of glycol. The mixture was then cooled to 150 ⁰ C and the melt with 24.75 parts of butane tetracarboxylic acid and 24.75 parts was added 4,4-diaminodiphenylmethane ^f. After the temperature had been increased to 200 ^° C., 10 parts of water and glycol were distilled off. After 2 hours, a homogeneous clear melt with an inherent viscosity of 0.18 fdl / gl (measured as a 0.5% solution in N-methylpyrrolidone) was obtained.

The melt was worked up as described in Example 1 to give a dispersion. Glass mats were impregnated with the dispersion and ^{cured at 300 °} C. for 5 minutes. Glass fiber-reinforced laminates were then produced from the prepregs at 350 ° C. and under a pressure of 150 kgf cm ". These laminates had a flexural strength of 3600 kgf cm ~.

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Example 3

From 92.2 parts of trimellitic anhydride, 48.5 parts of 4,4'-diaminodiphenyl ether, 0.2 parts of manganese (II) acetate, 400 parts of glycol, 120 parts of 4,4'-diaminodiphenyl ether and 80.5 parts of 1,2, 3,4-butanetetracarboxylic acid was obtained according to Example 1, a viscous resin with an inherent viscosity of 0.189 dl / g (measured as a 0.5 / Sige solution in N-methylpyrrolidone at 30 ^° C.).

The resin was then dissolved in 500 parts of tetrahydrofuran at room temperature. After 2 hours the solution was with 400 parts of a 5% strength aqueous solution of a polyvinyl alcohol with a residual acetate content of 30 Mol .- # added. This produced a dispersion. Then 492 parts of tetrahydrofuran were distilled off, the temperature being increased to 95 ° C.

This production process gives aqueous dispersions with round particles, the maximum particle size of which is 5 / U.

The dispersion was used to coat copper foils, which were excellent exhibited elastic properties. They are suitable for the production of flexible printed circuits.

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Claims (6)

Claims 1. Aqueous polyamide-imide dispersions, characterized in that they 20-60 percent by weight of polyamide-imide with a particle diameter of less than 5 / um as well Contain 1 - 6 percent by weight of a water-thinnable protective colloid and the polyamide-imide is a condensation product the end (A) 35 - ^ 5 percent by weight of at least one aromatic diamine, (B) 10 - 60 percent by weight of an aromatic tricarboxylic acid anhydrides or their derivatives (C) 5- ^ 5 percent by weight of hexane, pentane and / or butane tetra carboxylic acid or its anhydrides and (D) 0-20 percent by weight of an aromatic tetracarboxylic acid or their derivatives. 2. A process for preparing aqueous Polyamidimiddispersionen I according to claim ₉ characterized in that the polyamide-imide ₉ initially dry and then using before. Wet grinding of dispersion mills with high local energy density 3. Process for the preparation of aqueous polyamide-imide dispersions according to Claim I _9, characterized in that a solution of the polyamide-imide in a cyclic ether in water is precipitated with the addition of protective colloid and the cyclic ether is removed. H. Aqueous Polyamidimiddispersionen according to claim 1, characterized in that the vinylpyrrolidone with vinyl and / or Acrylester and / or polyvinyl alcohol is used as water-dilutable protective colloid polyvinyl pyrrolidone, copolymers. 5. Use of the aqueous polyamide-imide dispersions according to Claim 1 as wire enamels. 6. Use of the aqueous polyamide-imide dispersions according to Claim 1 for the production of temperature-resistant impregnations and bonds. BASF Aktiengesellschaft 809820/0158
ORiGiNAL / NSPECTED