DE2415195A1 - PROCESS FOR THE PRODUCTION OF SOLVENT-FREE POLYURETHANE REACTION COMPOUNDS AND THEIR USE IN ELECTRICAL TECHNOLOGY - Google Patents

Description

»The 28th H» ri

Applicant Dr. Bsck & Co. AG., 2 Hamburg 28, 9 A 1 £ 1 Q £ Grogmannstr ^ lOIS

Process for the production of solvent-free Polyurethane reactants and their use in electrical engineering

The invention relates to a method for producing Solvent-free polyurethane reaction media are required for the Used as insulation material in electrical engineering.

It i # t also more often. Patent ear lift 268 4l5 known » To produce purely aliphatically structured, branched polyester or polyetherps-lyurethane, and to produce them as air-conditioning-free Casting resins or reaction s »a * een for production of weather-resistant insulators or insulator covers.

According to the patent specification, the polyester polyurethanes are e.g. from adipic acid polyester kit hydroxy equivalents of \ 100 to 2000 and from hexeneethylene or tri-methylhexamethylene diisocyanate manufactured.

A major disadvantage of those used in the prior art Hvdroxypolyeater lies in the fact that it is at room temperature have an unfavorably high viscosity, so that processing is only possible at elevated temperatures is possible. Due to their high viscosity, fillers are very difficult to incorporate.

A way has now been found to incorporate solvent-free polyurethane reaction " to manufacture on the basis of such hydroxypolyesters $ whose viscosities are processed at 25 ° C ·? The technically favorable range of less than 10,000 cP, so that the addition of color and fillers without further ado possible 1st.

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According to the patent aollea mentioned by the German Technical Authority, alcohol © or carboxylic acids are preferably used for the production of the hydroxypolyesters, the esters of which are particularly weatherproof and hydroiys®b © 3-resistant. These include alcohols whose hydroxyl groups are on secondary carbon atoms and carboxylic acids whose Carboxyl groups are on tertiary carbon atoms.

Alcohols with secondary hydroxyl groups and carboxylic acids with tertiary carbxy groups, however, lead to polyesters or sssa polyester polyureihanen as end products, which have a lower thermal resistance than the products from exclusively alcohols old primary hydroxyl groups and from carboxylic acids old have primary carbxy groups. As is well known, however, the Väraebeständlgkeit an insulating material very important factor for its application. With the present invention, the 'task dissolved, weatherproof or hydrolysis-resistant polyester polyurethanes which also have an increased thermal resistance.

It has been found that from aliphatic dicarboxylic acids with preferably at least 9 carbon atoms and from polyhydric alcohols salt, preferably at least 6 carbon atoms, the carboxy groups or the hydroxyl groups preferably being on primary carbon atoms, low-viscosity polyesters are obtained which at 25 ° C have viscosities of < have 10,000 cP and with aliphatic and / or cycloaliphatic polyisocyanates Reaktionsmaseen result, the erhühte the insulators produced therewith or _c leolatorUberzttgen and electronic components. give thermal resistance and, due to their non-polar hydrophobic molecular structure, moisture resistance.

4098A6 / 0703

As particularly »advantageous for dividing up relative low-viscosity hydroxypolyeatern with in the heat Favorable electrical properties of the manufactured from it In polyurethanes, the use of azelaic acid has been shown to be the dicarbamic acid.

Among the longer-chain dicarboxylic acids are allea rait dodecane-l, 12-dicarboxylic acid favorable results obtain. Unfortunately, the high price of an economic utilization of this acid is still in the field.

As a diol with at least 6 carbon atoms and exclusively primary hydroxyl groups, it is advantageous to use 1,6-trimethylhexanediol. The technical grade is an isomer mixture of roughly equal parts 2,2,4 and 2, k , 4-trimethylhexanediol-l, 6.

The preferred use of diols with primary hydroxyl groups is intended to mean the use or co-use of diols with secondary hydroxyl groups such as 2-ethylhexanediol-1,3 cannot be excluded. This diol leads to end products with less favorable electrical properties in the market than Trimethylhexanedol-1,6, However, they have it Hydroxypolyester produced at 25 ° C viscosities <10,000 cP and have the desired resistance to hydrolysis.

In addition to the diols mentioned, a large number of other diols such as propylene glycol-1,2, butylene glycol-1,4, 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, 2,2-Dliaethylhexanediol-1,3 and neopentyl glycol proportionately to be used for the production of the hydroxypolyester.

An exclusive use of the last-mentioned diols cannot be within the meaning of the invention, since the hydroxypolyesters thus obtained either do not have the desired favorable hydrolysis resistance or they tend to crystallize.

4Q9846 / 0703

Likewise, the preferred use of aliphatic dicarboxylic acids with at least 9 carbon atoms, such as azelaic acid, should not exclude the use of other aliphatic dicarboxylic acids such as adipic acid.

When selecting such dicarboxylic acids, however, the hydrolysis resistance of the polyester-polyurethanes is also important to pay attention to the unsatisfactory result of using too large proportions of short-chain dicarboxylic acids will. Here, too, the tendency of most polyesters to crystallize must again be taken into account.

While the azelaic acid polyester described in the examples Remaining liquid even after prolonged storage is the result of liquid adipic acid polyesters otherwise identical composition a crystalline sediment, which of course processing technology seen is disadvantageous.

According to the invention, trimethylolpropane is preferably used as the trifunctional alcohol, but hexanetriol, trimethylolethane and glycerol can also be used. The proportion of short-chain dicarboxylic acids and short-chain polyhydric alcohols used should not exceed 20 mol% of the total amount of the carboxylic acids and alcohols.

The hydroxyl polyesters produced from the raw materials described can be mixed with the polyurethane cast resin systems common fillers such as quartz flour, Mikrodol, MlkrogliBuner and porcelain flour as well as with fillers such as aluminum oxide hydrate and melamine.

Isocyanates other than those mentioned in the aforementioned patent have been found to carry out the curing reaction aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate, the cycloaliphatic diisocyanates such as e.g.

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Isophorone diisocyanate and 3,3'-dimethyl-4, h * diieocyanatodicyclohexylmeth & n particularly proven. The use of these special isocyanates is a further characteristic component of the process according to the invention.

The formation of polyurethane can be accelerated by adding customary accelerators Amines, diazabicyclooctane »iron acetylacetonate and others can be achieved

The insulators or insulator covers produced from the reaction mixtures according to the invention show excellent weather resistance and also resistance to external leakage currents and arcs. In addition, they are resistant to temperature increases to 100 to 110 ° C. This temperature resistance means that there is a risk of damage to the outer insulator layer in particular excluded by prolonged exposure to the sun.

The electronic ones encapsulated with the reaction masses Component can withstand permanent temperatures of 80 - 90 ° C.

The invention is illustrated by the following examples.

Example 1:

3 moles of azelaic acid 3 moles of trimethylhexanediol-1,6 and 1 mole of trimethylolpropane are introduced with CO. and condensed with stirring at 200 ° C. until no more water of reaction distills over. The condensation is then continued at 200 ° C under vacuum for about 5 hours until the acid number is less than 5 and the hydroxy equivalent is 36Ο - 370. The viscosity is then at 25 ⁰ C for about 65ΟΟ cP.

The polyester obtained is mixed with various diisocyanates hardened

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1) 100 great polyester

30.5 Part · isophorone di · gel time is approximately 250 minutes at 8O ⁰ C.

2) 100 parts polyester

29 "Trimethylnexamethylendiisocyanat Di · G" lz # it is about 250 minutes at 8O ⁰ C.

3) 100 parts polyester

^ O "3,3» -Dimethyl-4,4'-diisocyanatodicyclo-

hexylmethane. Di · gel time is 230 minutes at about 8O ⁰ C.

Example 2;

2.77 moles azelaic acid, 2.77 moles-2-ethylhexanediol-1,3

and 1 mol of trimethylolpropane are _{condensed with passing in CO 2} and with stirring at about -170 ° C. until no more water of reaction distills over.

Then 4 hours at 210 ° C then 5 hours at

210 ^e C and 45-55 Torr condensed.

The vacuum condensation continues as long as

until the acid number is less than β 2 and that »hydroxy

Equivalent weight is 320-325. The viscosity

is then approx. 6200 cP ^{at 25 ° C.}

The polyester obtained is cured as follows:

1) 100 parts polyester

33 ^w Isophorondlieocyanat gel time at 8O ⁰ C for about 250 minutes.

2) 100 parts polyester

32 * Trimethylhexaeethylendiieocyanat gel time at 8O ⁰ C for about 250 minutes.

3) 100 parts polyester

^ 5 ⁿ 3 »3'-Eimethyl-4,4» -diisocyanato-

dicyclohexylmethane gel time at 80 ° C approx. 240 min.

409846/0703

Example 3t

4.5 moles of azelaic acid, 4.5 moles of 2-ethylhexanediol-1,3 and

1 mole of Trlmethylolpropane are introduced with the introduction of

CO ₂ and condensed with stirring at about 170 ° C until

no more water of reaction distilled over. It will be added

Condensed for 4 hours at 210 ° C and 45-55 Torr.

The vacuum condensation continues as long as

until the acid number is less than 2 and the hydroxy

Equivalent weight is 490-500. The viscosity is then approx. 9000 cP at 25 ° C. The polyester obtained is cured as follows

1) 100 parts polyester

22 "xsophorone diisocyanate gel tent at 80 ° C for approx. 270 min.

2) 100 parts polyester

21 parts of trinethylhexaiaethylendliaocyanct Gel time at 80 ° C approx. 270 min.

3) 100 parts polyester

29 parts of 3,3'-dimethyl-4,4 ^l -diisocyanato? Licyclo-

hexylmethane gel time at 80 ° C approx. 260 min.

The following table shows that the inventions £ -emektiven Products are better than the products on Basin pure aliphatic polyether polyols according to the Austrian patent " font 268 415.

The slower rise in the dielectric loss factors compared to the comparable product is particularly favorable and faster drop in resistance with temperature increases.

The Verte de »volume resistance after water storage prove the good hydrophobicity of the products. The Shore hardness is relatively low.

409846/0703

Dielectric example 1 Example 2 Example 3 Commercially available branched TMDI activity number RT IPDI TMDI. 'IPDI IPDI containing hydroxyl groups ⁴ ^ kO Polyether 170 P. ⁶⁰ IPDI Dielectric co 90 850 Verlu 31 JTakt or
XO · RT • t- 105 850 100 I5OO 245 I9OO 2500 40 co 130 300 100 i 420 75 > 10000 60 ^ 155
«-» 250 650 '. 135 170 I7OO - 90 Q through <-
_ω resistance RT 2200 4ooo 7OO 1500 > 10000 105 Q χ cm
40 3700 3000 1800 2800 130 60 65ΟΟ 9400 - 4ioo - 7.9 155 90 > 10000 > 10000 • - - 105 6.5 130 5.8 7.0 5.0 6.0 4.8 ", 5.8 6.3 6Λ 6.3 5.7 mm 5.8 5.8 6.0 5.4 XX.9 ■ ~ 5.1 5.1 5.3 4.9 5.2 5.1 4.9 4.5 - 10 ⁱ² 5.2 - 4.2 - - - - - 10 ¹¹ 10 ¹⁴ 10 ¹² 10 ¹ * 10 ¹ * ΙΟ « 10 ¹⁰ 10 ¹ ^ 10 ¹² ■ ιο ^χ 3 10 ¹² fm 10 ¹⁰ 10 " 10 ¹¹ > '10 ¹² • id ¹¹ ao ¹⁰ XO? 10 ¹⁰ 10 ¹⁰ ίο-? ¹ ΙΟ ¹¹ 10 ⁹ 10 ¹⁰ 10 ¹⁰ 10 ¹⁰ 10 ¹⁰ 10 ¹⁰ 10 ¹⁰ 10 ⁹ 10 ⁹ -

Transit
-Resistance b.RT after left storage 0 h Q χ cm _{2k h}

48 h

10 ¹⁴
10 ¹²
IOI2

10 ¹⁴ 10 ¹²

1012

Example 1 IPDI TMDI

Example 2 IPDI

Example 3 IPDI

Commercially available branched polyether containing hydroxyl groups
IPDI TMDI

h 2 * 10 h.

10

10

ts>

12th

Shore hardness A

TMDI * trimethyl hexaatethylene diocyanate IPDI β isophorone diisocyanate

Claims (3)

Claims 1)! Process for the production of solvent-free polyurethane reaction compounds for use as insulation material in electrical engineering based on hydroxyl-containing polyesters and polyisocyanates and optionally fillers, dyes and accelerators, characterized in that a hydroxyl-containing polyester made from aliphatic dicarboxylic acids with at least 9 carbon atoms and preferably primary carboxyl groups and from polyhydric alcohols with at least 6 carbon atoms and preferably primary hydroxyl groups with the use of 0-20 MoJ. on short-chain dicarboxylic acids and / or kurakettig9n polyhydric alcohols, calculated on the total amount of rol , has been prepared, is cured with aliphatic and / or cycloaliphatic polyisocyanates. 2} Use dmr according to claim 1 produced polyurethane reaction mixtures for the production of Insulators or insulator covers. 3) Use of the polyurethane reaction compounds prepared according to claim 1 as casting compounds for electronic components. 409846/0703