SU395421A1 - METHOD OF OBTAINING POLYURETHANE - Google Patents

Description

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This invention relates to the production of polyurethanes suitable for the manufacture of paint and varnish coatings.

A known method for producing polyurethanes by the interaction of polyisocyanates and epoxy compounds modified with dialkanolamines.

However, the use of known zinc compounds, for example, glycinol ester based on aliphatic monocarboxylic acids, produces low viability compositions (from 40 seconds to 4 minutes), which makes it difficult to use them to produce coatings.

In order to increase the viability of the composition, cycloaliphatic or alicyclic diepoxides have been proposed as starting epoxides.

Depending on the nature, the diepoxides are modified by dialkolampolamps (aliphatic, alicyclic) at a room or elevated temperature P00 ° for 2-3 hours at a molar ratio of diepoxide; dialkanolamine 1: 0.1-1: 1 (in terms of equivalents 1: 0.05-1: 0.5). The modification provides only a partial conversion of the epoxy groups of the oligomer.

Linear or branched macroisocapates based on aliphatic or aromatic diisocyanates are used as iolisocyanates for the preparation of polyurethane film-forming compositions, which provides for the low toxicity of polynethane varnishes.

Na-primer, macroiso, myanates, containing free isocyanate groups, obtained by reacting hydroxyl-containing substances (polyester or polyether linear or split), without blends, diols, trpols — glycerol or its ethers, trimethylolpropane, etc., with diisocyanates (hexametane diisocyanate, heptane, isomers, etc.) 4-2,6-toluene diisocyanate or a mixture thereof, 4,4-diphenylmethane diisocyanate, etc.) or macro-isocipates of biuret structure.

The molar ratio of the isocyanate-containing component and the depalkanolamine-modified diepoxide in the lacquer can vary from 3: 1 to 1: 2. The lacquer is obtained by combination with a modified diepoxide with a pH of at room temperature in an organic solvent medium. Varnish life ability not less than 24 - 48 hours. Suvi coating at 100-120 ° С for 3 hours.

It forms 1TC11 coatings and imposes defect-free, colorless, transparent, with a good shine of 1m decorative gloss, materials that have good adhesion and high

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physico-mechanical indicators, as well as good chemical and weathering resistance.

Example 1. To 15 g of cycloaliphatic diepoxide formula

CH2-0-CH, -CH-CH7

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1.23 g of freshly distilled diethanolamine is added and stirred at room temperature for an hour until a clear, homogeneous liquid is obtained.

4 g of the modified dienoxide is combined with 9.5 g of polyurethanate biuret structure, obtained on the basis of 3 lula hexamethylene diisocyanate and 1 mol of water, in 10 ml of cyclohexanone. L disability varnish 48 hours. Cover dry at 120 ° C for 3 hours. The resulting film has a hardness of 0.75, an elasticity of 1 mm, a shock resistance of more than 50/50 kg / cm, a tensile strength of 450 kg / cm and an elongation of 40-50%. After an ekschnitsitsii in the IP-1 gauge for 100 hours, the strength and elongation at break remained practically unchanged.

The coatings deposited on the round metal rods remain defect-free 1) 1 mn after staying for 100 hours in 10% NaOli solution at 50 ° C and in boiling acetone.

Example 2. To 19.18 g of a modified diepoxide, according to lawn 1, was added 6.2 g of niisophosphate of biuret structure and 20 ml ml of cyclohexapone. Viability of the obtained varnish 48 hours The mode of the cured coating is the same as in example 1. The cured coating is a shiny, starless material, possessing: relative hardness of 0.75, elasticity of 1 mm, impact resistance of more than 50/50 kg / cm2, 200 kg / cm break, elongation 80%.

Example 3. 25 g of diepoxinda of the formula.

CH, gO-C- (CH -,), g (-0-CH7 OO

mixed with 7.2 g of diethanolamine and maintained at 100 ° C for 2 hours. 4 g of the modified dienoxide is combined with 8 g of a polyisocyanate adduct obtained on the basis of 1 mol of trimethylolpronan and 3 mol of 2.4 toluene diisocyanate, and 10 ml of a mixture of cyclohekeanone and methyl ethyl ketone. Viability varnish 36 hours. The film cures at 100 ° C for 2 hours. The cured film is transparent, colorless, free of defects, with a good decorative appearance, it has a relative hardness of 0.8, elasticity of 1 mm, impact resistance of more than 50/50 kg / s, a tensile strength of 660 kg / cm and relative elongation of 40%.

Example 4. 3 g of modified diepoxide, according to example 3, is mixed with 3.5 g of macroisocyanate obtained by the interaction of 2 mol of 4,4-dphenylmetadiisocyanate with 1 mol of oligodiethylene glycol adipinate containing 3.2% hydroxyl

groups and 3.6% of carboxyl, 0.6 g of a polyisocyanatine adduct, obtained by the interaction of 1 mole of methyl methanol propane and 3 moles of 2,4-toluylenpizotsnaiat, and 10 ml of cyclohexapone. 24 hour lacquer vitality The coating obtained is a transparent, non-glossy lint with a good decorative look, a relative hardness of 0.4, an elasticity of 1 mm, a tensile strength of 300 kg / cm2 and an elongation of 130%.

Subject invention

The method of producing polyurethanes by reacting epoxy compounds with single alkanols with subsequent treatment of the reaction products with poly (nsocyanates) in an inert solvent, characterized in that cycloaliphatic or aliquicles are used to increase the viability of the polyurethan compounds obtained by the epoxy compounds.