CS196997B1 - Method of curing epoxysiloxane resins - Google Patents

Description

The invention relates to a process for curing epoxy siloxane resins with a mixed catalyst, in particular for the production of reinforced materials, preferably glass laminates.

Epoxysiloxane resins prepared, for example, by the reaction of methylsilyl polysiloxane resins containing methoxy and / or hydroxyl groups and epoxy polymers based, for example, on epichlorohydrin and 2,2-bis (p-hydroxyphenyl) propane can be cured at elevated temperatures up to 300 ° C. curing catalysts: aliphatic, cycloaliphatic or aromatic polyamines, phenol-aldehyde or urea-formaldehyde resins, polyfunctional acids or their anhydrides, etc. (e.g., U.S. Pat. No. 3,154,597, U.S. Pat. No. 3,455,877, Britishrit. 864,697). A quaternary ammonium base was used to cure epoxysiloxane resins having a low content of epoxy and hydroxyl groups capable of participating in the curing process (cf. No. 165890). However, the resin or product prepared using epoxy siloxane resin and quaternary ammonium base needs to be further hardened at elevated temperature, but even then the binder is not sufficiently crosslinked, resulting in, for example, less resistance to organic solvents. Increasing the degree of curing cannot be achieved by adding more catalysts, since the catalysed lacquer then has a low shelf life, and in particular increases the risk of resin hardening even when the glass fabric is impregnated, even at drying temperatures.

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Mp 198 997-90 ° C. If the drying temperature is lowered, the solvent is not completely removed and the quality laminates cannot be pressed.

Said drawbacks can be substantially reduced as curing epoxy siloxane compositions of this invention which consists in the fact that AE epoxy siloxane resin is mixed with the quaternary ammonium base of the general VORC ^ (RjRgRjR ^ JNJ ⁺ X ", Me, R, Hg, R ^ and R ^ are alkyl C 1 -C 4 alkyl, phenyl optionally substituted with C 1 -C 3 alkyl, X is an alkoxy group wherein C 1 -C 6 alkyl, optionally hydroxy or C 2 -C 6 acyloxy, in an amount of 1.10 "? up to 1% by weight on the resin, and with zinc or cobalt salts of fatty acids saturated or unsaturated with a number of carbon atoms of 6 to 24 in an amount of 1.10 to 9.10 ^rl by weight of metal on the resin, and the resin so treated is cured at temperature 80 ⁰ to 250 ° C.

According to the invention, the epoxysiloxane resin produced by the reaction of methylphenylpolysiloxane with the epoxy resin in different weight ratios can be cured according to the invention with a mixed catalyst, i.e. a quaternary ammonium base and a metal salt of a fatty acid. No. 165889. Preferably, the mixed catalyst may cure less epoxy siloxane resin; more than 5% epoxy groups.

The epoxysiloxane resin is admixed, preferably in an organic solvent solution, with a quaternary ammonium base of the type ((R, R, R, R, R, N), for example with tetramethylammonium hydroxide, benzyltrimethylammonium hydroxide etc. in an amount of 1.10 to 1.0% by weight on the resin. This solution is further homogenized with a metal salt of a fatty acid in an amount of 1.10 ^- 9.10 ¹ % by weight per resin.

According to the invention, the metal fatty acid salt is understood to mean, for example, octoates, stearates, naphthenates, linolates, etc., zinc, cobalt, zirconium salts, etc.

Research has found that in the presence of a metal salt of a fatty acid, the epoxysiloxyne resin can be catalyzed by a quaternary mannium base in substantially greater amounts than without the metal salt. The catalysed system has a good processing time and there is no danger of binder hardening when painting the glass fabric for the preparation of glass laminates. La. minates prepared using epoxy siloxide resin and mixed catalyst have good mechanical properties and exhibit lower weight loss when immersed in an organic solvent. This suggests that under the same glass fiber laminate production conditions, the binder cured, i.e. higher, when the mixed catalyst is used.

density of the polymer network.

The use of the mixed catalyst and the properties of the glass laminates are exemplified in the examples.

I Example 1

AND

To a solution of epoxysiloxane resin in toluene (prepared according to

¹ Certificate No. 165889, dry matter 63.9% by weight, viscosity 114.8 mPa.s / 25 ° C, epoxy group I content 0.034 g eq / 100 g) a solution of tetramethylammonium hydroxide in butanol (base content 6.2%) was added %) in an amount of 0.077 and 0.155 wt. based on the polymer, the blends were perfectly

19-997 were mixed and measured for their gelling time by the Gough and Stoith method at temperatures of 110-150 ° C. At the same time a sample of epoxysiloxane resin containing quaternary ammonium base and zinc octoate was prepared and gelling times were measured again. The results are shown in Table 1.

Table 1 gelatinization times quaternary base amount Zn gelatinization time (a) (% w / polymer) (% w / polymer)

T = 110 ° C Mp: 140 ° C Mp 150 ° C 0,077 - 388 129 90 0.155 - 233 100 ALIGN! 70 0.155 0,047 392 130 92

It can be seen from Table 1 that the addition of Zn salt made it possible to double the amount of quaternary ammonium base to twice the same gelation times.

Example 2

The epoxysiloxane resin (as in Example 1) was catalysed with tetramethylammonium hydroxide and metal salts (Zn-octoate. Co-naphthenate) in the amount shown in Table 2. The EV 99-206 (K4) glass cloth was impregnated with the lacquer. 90 ° C. From the impregnated fabric, glass laminates with a thickness of 3 mm, a compression pressure of 6.0 MPa, a compression temperature of 180 ° C and a time of 60 minutes were pressed. The resulting laminates having a binder content of < 30 > 2% were cured at 200 [deg.] C. for 6 hours and 250 [deg.] C. for 2 hours. The properties of the laminates are given in Table 2.

Table 2

Preparation and properties of glass laminates

% Cat gelatine- limit fortress resistant against quaternary metal time in bend trichlorethylene base salt (/ 150 ° C) (MPa) and b 0.134 Zn 0.009 180 370 unchanged 2.4 0.134 Co 0.013 115 385 N 3.5 0,076 170 390 total de- 7.3 strukce 0.134 57 C - -

a ... evaluation after 7 hours of boiling b ... water absorption after 24 hours at 23 ° C /% w / w ... laminate cannot be pressed

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It can be clearly seen from Table 2 that a glass laminate prepared using only a quaternary base is strongly attacked by tri-chloroethylene, and when the base content is increased without the application of metal salts, the laminate cannot be prepared at all due to curing of the resin before compression.

When using a mixed catalyst, the amount of quaternary base can be increased and the laminates exhibit higher resistance to trichlorethylene due to the higher degree of cure.

Claims (1)

. Pressurized feed vessels curing epoxy siloxane mixed catalyst vyznaSený that ee epoxyailoxanová resin is mixed with the quaternary ammonium base of the general formula £ (R rjh ^ ~ nJ ^{+ x} "where B].» ®2 ^fi · 3 ^{and E} 4 j ^sou alkyl β 1 X is alkoxy, wherein the alkyl contains 1 to 6 carbon atoms, optionally hydroxy or aeyloxy, and 2 to 6 carbon atoms, in an amount of 1 to 10 carbon atoms; % by weight of the resin, and the zineěnatou or cobalt salts maetné kyeeliny saturated or unsaturated carbon number 6 to 24 in an amount of 1.10 ^J to 9 · 10% strength by weight of metal on the resin, so prepared resin ee after cured at teplotfe 80 ^0-250 Deň: 32 ° C.