RU2122006C1 - Liquid prepolymer hardener with end isocyanate groups - Google Patents

Abstract

FIELD: chemistry of polymers, more particularly manufacture of cast products from polyurethane elastomers and polyurethane coatings. SUBSTANCE: present invention describes liquid prepolymer hardener having good aggregate stability at temperatures below 90 C. Liquid prepolymer hardener with end isocyanate groups includes 3,3'-dichloro-4,4' -diaminodiphenyl methane and non volatile solvent. Said unvolatile solvent includes polyols with molecular weight of 2100-5000, the ratio of components is as follows, wt.pts): 3,3'- dichloro-4,4'-diamino-diphenyl methane, 20-50; and nonvolatile solvent, 80-50. EFFECT: improved properties. 1 dwg, 9 ex, 1 tbl

Description

 The invention relates to liquid hardeners of prepolymers with terminal isocyanate groups used to obtain injection molded products from polyurethane elastomers, polyurethane coatings, etc.

The aromatic diamine 3,3'-dichloro-4-4'-diaminodiphenylmethane (trade name Dia. X) used as hardener of prepolymers with terminal isocyanate groups provides a high level of properties of polyurethane elastomers. However, it is a crystalline substance with a high melting point (about 105 ^o C), which creates difficulties in its processing (high energy consumption for heating equipment, high toxicity of vapors of Diamett X at temperatures above 100 ^o C, the risk of formation of plugs from unmelted Diamete X in the circulation channels of equipment, etc.) (Wright P., Kimming A. Polyurethane elastomers. Leningrad. "Chemistry", 1973).

It is urgent to develop methods for modifying Diamet X to transfer it to a liquid state of aggregation at low temperatures (20-90 ^o C) without a significant deterioration in the properties of polyurethane elastomers.

A known method for solving this problem is to use as a liquid hardener a solution of a mixture of aromatic diamines 3,3'-dichloro-4-4'-diaminodiphenylmethane and 3,3'-dichloro-4-4'-diaminotriphenylmethane in a 1: 1 molar ratio, in the amount of 60-75 parts by weight in a non-volatile solvent (polyol or oligoester acrylate with mol.m. 90-2000) in an amount of 40-95 parts by weight (A.S. USSR N 615095 class. C 08 G 18/32, 1978). This composition of the liquid hardener provides good aggregate stability of the solution of diamine in a non-volatile solvent at a temperature below 90 ^o C, including at a high concentration of diamine.

 However, the use of a mixture of aromatic diamines not only increases the solubility of diamine in a non-volatile solvent, but also creates an irregular structure of the urea hard blocks of the obtained polyurethane elastomers, which leads to a decrease in their properties (hardness, strength, etc.).

 Another way to solve this problem, the closest to the proposed one, is to use, as a liquid hardener, a solution of Diamet X in a non-volatile solvent-polyoxytetramethylene glycol with a mol.m. 500-1000, in the following ratio of components, parts by weight

Diameter X - 2.6 - 50
Non-volatile solvent - 97.4 - 50
(U.S. Patent No. 3,718,624, CL C 08 G 22/14, 1973).

The disadvantages of this liquid hardener include the instability of the aggregate state of the Diameter X - polyoxytetramethylene glycol system at a temperature below 90 ^o C and the content of Diametre X over 30 parts by weight, and, therefore, the impossibility of obtaining a liquid hardener with a high concentration of Diamett X, which is necessary to ensure properties of polyurethane elastomers approaching the properties of elastomers based on pure Diamet X.

The aim of the invention is to obtain a liquid hardener of prepolymers with terminal isocyanate groups, which is a solution of Diamet X in a non-volatile solvent with good aggregate stability in the temperature range below 90 ^o C and providing a high level of properties of polyurethane elastomers obtained on its basis.

где m_ДA и m_гсс - содержание Диамета Х и гидроксилсодержащего соединения в смешанном отвердителе, мас.ч. На чертеже представлены зависимости твердости полиуретановых эластомеров на основе предполимера (продукт взаимодействия полиокситетраметиленгликоля с мол. м. 1000 и ТДИ) и смешанного отвердителя, включающего Диамет Х и гидроксилсодержащее соединение, от состава отвердителя. Вид гидроксилсодержащего соединения: кривая 1-1,4 бутандиол (C $\genfrac{}{}{0ex}{}{\text{кр}}{\text{гсс}}$ = 0,09), кривая 2-полиокситетраметиленгликоль с мол.м. 1000 ( $\genfrac{}{}{0ex}{}{\text{кр}}{\text{гсс}}$ = 0,38) , кривая 3-полиокситетраметиленгликоль с мол.м. 2000 (C $\genfrac{}{}{0ex}{}{\text{кр}}{\text{гсс}}$ = 0,53). Из полученных данных следует, что в области C_гсс< C $\genfrac{}{}{0ex}{}{\text{кр}}{\text{гсс}}$ свойства полиуретановых эластомеров по мере роста C_гсс меняются мало и приближаются к свойствам эластомеров на основе чистого Диамета Х. В области C_гсс< C $\genfrac{}{}{0ex}{}{\text{кр}}{\text{гсс}}$ увеличение C_гсс сопровождается падением свойств полиуретановых эластомеров. Величина C $\genfrac{}{}{0ex}{}{\text{кр}}{\text{гсс}}$ зависит от молекулярной массы гидроксилсодержащего соединения и возрастает при ее увеличении. Из этого следует, что при увеличении молекулярной массы гидроксилсодержащего соединения его содержание в смешанном отвердителе может быть увеличено без значительного ущерба для свойств полиуретановых эластомеров.We have studied the properties of polyurethane elastomers based on prepolymers with terminal isocyanate groups and mixed hardeners, which are a solution of Diamet X in a hydroxyl-containing compound of different chemical structure depending on the composition of the hardener. At the same time, it was unexpectedly found that a critical concentration of hydroxyl-containing compound can be isolated on the dependences of the properties of elastomers on the composition of the mixed hardener

where m _DA and m _gss - the content of Diamet X and hydroxyl-containing compounds in the mixed hardener, parts by weight The drawing shows the dependences of the hardness of polyurethane elastomers based on prepolymer (the product of the interaction of polyoxytetramethylene glycol with a molecular mass of 1000 and TDI) and a mixed hardener, including Diametre X and a hydroxyl-containing compound, on the composition of the hardener. Type of hydroxyl-containing compound: curve 1-1,4 butanediol (C $\genfrac{}{}{0ex}{}{\text{cr}}{\text{gss}}$ = 0.09), the curve of 2-polyoxytetramethylene glycol with a mol.m. 1000 ( $\genfrac{}{}{0ex}{}{\text{cr}}{\text{gss}}$ = 0.38), the curve of 3-polyoxytetramethylene glycol with a mol.m. 2000 (C $\genfrac{}{}{0ex}{}{\text{cr}}{\text{gss}}$ = 0.53). From the data obtained it follows that in the region C, _gcc <C $\genfrac{}{}{0ex}{}{\text{cr}}{\text{gss}}$ the properties of polyurethane elastomers do not change much with the growth of C _gcc and approach the properties of elastomers based on pure Diamet X. In the region C, _gcc <C $\genfrac{}{}{0ex}{}{\text{cr}}{\text{gss}}$ an increase in C _{gcc is} accompanied by a drop in the properties of polyurethane elastomers. Value C $\genfrac{}{}{0ex}{}{\text{cr}}{\text{gss}}$ depends on the molecular weight of the hydroxyl-containing compound and increases with its increase. From this it follows that with an increase in the molecular weight of the hydroxyl-containing compound, its content in the mixed hardener can be increased without significant damage to the properties of polyurethane elastomers.

 Thus, the goal can be achieved by using as a non-volatile solvent in the composition of the liquid hardener polyols in mol.m. 2100-5000 in the following ratio of components in parts by weight

3,3'-dichloro-4,4'-diaminodefinyl-methane - 20-50
Non-volatile solvent - 80-50.

According to the invention, the following raw materials are used:
Aromatic diamine - 3,3'-dichloro-4,4'-diaminodefinylmethane (Diameter X)
TU 6-14-980-84
Non-volatile solvent:
- polyoxytetramethylene glycol mol.m. 1000 (polyfurite) TU 6-02-646-81
- polyethylene butylene glycol adipate mol.m. 2100 (polyester P5 14) - TU 2226-206-21081385-96
- polyethylene glycol adipate mol. m. 2200 (P6 polyester) TU 38.103582-85
- polydiethylene glycol adipate mol. m. 3200 (polyester P528) TU 6-05-221-687-86
- polyoxypropylene glycol mol.m. 1000 (laprol 1052) TU 6-05-2035-87
- polyoxypropyleneoxyethylene glycol mol.m. 3500 (laprol 3502-2B-20)
TU 6-05-2035-87
- polyoxypropyleneoxyethylene glycol mol.m. 3500 (laprol 3502-2B-20)
TU 2226-318-10488057-94
- polyoxypropyleneoxyethylenetriol mol.m. 5000 (laprol 5003-2B-10)
TU 2226-0008-10488-057-94
- a mixture of isomers of 2,4 and 2,6-toluene diisocyanate (product T80) TU 113-03-12-17-85.

 As prepolymers with terminal of cyanate groups, prepolymers based on polyols and toluene diisocyanate can be used.

Liquid hardener can be obtained by mixing Diamet X with a non-volatile solvent at a temperature of 90 ^o C until it is completely dissolved with stirring. Subsequently, the solution is cooled to a predetermined temperature (20-90 ^o C).

Mixing a liquid hardener with a prepolymer when molding products from polyurethane elastomer can be carried out at a temperature of from 20 to 90 ^o C.

The invention is illustrated by the following examples:
Example 1

 Liquid hardener contains 20 parts by weight Diameter X and 80 parts by weight polyethylene butylene glycol adipate with mol.h. 2100.

100 parts by weight Isocyanate-terminated prepolymer, which is the product of the interaction of polyethylene glycol adipate with mol.m. 2200 with a mixture of isomers 2.4 and 2.6 TDI, mixed with 36.23 wt.h. the specified liquid hardener (NCO: NH ₂ + OH = 1.05) at 90 ^o C, the mixture is poured into a mold heated to 100 ^o C and utverjdayut at 100 ^o C for 20 hours. After removing from the mold a sample of polyurethane elastomer is kept 10 days at 20 ^o C, then determine its properties (table).

 Example 2

 Liquid hardener contains 30 parts by weight Diameter X and 70 parts by weight polyethylene butylene glycol adipate with mol.h. 2100.

 100 wt. including prepolymer with terminal isocyanate groups used in example 1, cure 24.47 parts by weight of the specified liquid hardener and get a sample of the elastomer in example 1. The properties of the elastomer are shown in the table.

 Example 3

 Liquid hardener contains 40 parts by weight Diameter X and 50 parts by weight polydiethylene glycol adipate with mol.m 3500.

 100 wt. including prepolymer with terminal isocyanate groups used in example 1, cure 24.38 wt.h. the specified liquid hardener and receive a sample of the elastomer according to the procedure similar to example 1. The properties of the elastomer are shown in the table.

 Example 4

 Liquid hardener contains 40 parts by weight Diametre X and 60 parts by weight polyoxypropylenexyethylenetriol with mol.m. 5000.

 100 parts by weight prepolymer with terminal isocyanate groups, which is the product of the interaction of polyethylene butylene diethylene glycol adipate with mol.m. 2000 with a mixture of isomers 2, 4 and 2.6 TDI, mixed with 25.58 parts by weight the specified hardener and get a sample of the elastomer according to the procedure similar to example 1. The properties of the elastomer are shown in the table.

 Example 5

 Liquid hardener contains 50 wt.h. Diameter X and 50 parts by weight polydiethylene glycol adipate with mol.m 3500.

 100 wt. including prepolymer with terminal isocyanate groups used in example 4, mixed with 26,11 parts by weight the specified hardener and receive samples of the elastomer according to the procedure similar to example 21. The properties of the elastomer are shown in the table.

 Example 6

 Liquid hardener contains 50 wt.h. Diameter X and 50 parts by weight polyethylene butylene glycol adipate with mol.m. 2100.

 100 parts by weight prepolymer with terminal isocyanate groups, which is the product of the interaction of polyoxytetramethylene glycol with a mol.m. 1000, mixed with 21.6 wt. including the specified hardener and receive samples of the elastomer according to the procedure similar to example 1. The properties of the elastomer are shown in the table.

 Example 7

 Liquid hardener contains 40 parts by weight Diametre X and 60 parts by weight polyoxypropyleneoxyethylenediol with a mol.m. 3500.

 100 wt. including prepolymer with terminal isocyanate groups used in example 6, mixed with 35.77 parts by weight the specified hardener and receive samples of the elastomer according to the procedure similar to example 1. The properties of the elastomer are shown in the table.

 Example 8

 Liquid hardener contains 50 wt.h. Diameter X and 50 parts by weight polyethylene butylene glycol adipate with mol.m. 2100.

 100 parts by weight prepolymer with terminal isocyanate groups, which is the product of the interaction of polyoxypropylene glycol with a mol.m. 1000, mixed with 28.74 parts by weight the specified hardener and receive samples of the elastomer according to the procedure similar to example 1. The properties of the elastomer are shown in the table.

 Example 9

 The liquid hardener contains 44.5 parts by weight of Diametre X and 55.5 parts by weight polyoxytetramethylene glycol with a mol.m. 1000.

 100 wt. including prepolymer with terminal isocyanate groups used in example 6, mixed with 20.76 wt.h. the specified hardener and receive samples of the elastomer according to the procedure similar to example 1. The properties of the elastomer are shown in the table.

Claims (1)

Liquid hardener of prepolymers with terminal isocyanate groups, including 3,3'-dichloro-4,4'-diaminodiphenylmethane and a polyol as a non-volatile solvent, characterized in that as a non-volatile solvent it contains polyols with mol.m.2100 - 5000 in the following the ratio of components, parts by weight:
3,3'-Dichloro-4,4'-diaminodiphenylmethane - 20-50
Non-volatile solvent - 80 - 50i

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