SU1121270A1 - Process for producing liquid polyurethanes with allyl end groups - Google Patents

Abstract

The formulation of the preparation of liquid polyurethane with final allyl groups by the interaction of 2,4-toluene diisocyanate, a high molecular diol and allyl alcohol in an organic solvent, characterized in that, in order to increase the content of allyl groups, the toothpaste is removed; the interaction between 2,4-toluenediisocyanate and allyl alcohol at their equimolar ratio, and then the interaction of the obtained product with a high molecular weight diol with an equivalent The valent ratio of NCO- and OH groups.

Description

ISO The invention relates to the field of producing liquid polyurethanes with terminal allyl groups and can be used in various industrial areas as additives to injection compounds, plasticizers of epoxy and acrylic resins, in compositions of polymeric adhesives, coatings. The closest to the invention in technical essence and the achieved effect is the method of obtaining liquid polyurethanes with terminal allyl groups by the interaction of high molecular weight diols with 2,4-toluene diisocyanate and the subsequent interaction of the obtained product with allyl alcohol. Such oligomers are stable during storage and practical use. However, along with the main condensation reaction, the polyaddition reaction can occur, resulting in the resulting oligomers are characterized by a high polydispersity with increased viscosity and low content of allyl groups, which causes low polymers. The aim of the invention is to increase the content of allyl groups, stages 1 through CH 3, NCO rQ -f. no-sn sn2O s (oHJ NHCOOCH, CH-dH

where R is the residue of a high molecular weight diol.

The first stage of the process is carried out in n-heptane at 20-25 C. As the product is formed, the product precipitates, which is filtered and washed. In the second stage, a molecular molecular diol is added to a 25% solution of mono-derivative 2,4-toluene diisocyanate in chloroform at an equivalent ratio of NCO and OH groups and the reaction is carried out in the presence of a catalyst, for example tin dibutyl dialurinate, at 20-25 ° C until the isocyanate groups disappear (6 h). The final product is isolated by precipitating B n-heptane 702 viscosity reduction and polydispersity (liquid polyurethanes with terminal allyl groups, the goal is achieved by the method of producing liquid polyurethanes with terminal allyl groups by reacting 254-toluene diisocyanate 5 with high molecular weight diol and allyl alcohol in the medium of an organic solvent, first interacting between 2,4-toluene diisocyanate and allyl alcohol at their equimolar ratio with the subsequent interaction The resulting product t is a high molecular weight diol with an equivalent ratio of NCO and OH groups. Polyethers, such as polyoxypropylene diols, with a molecular weight of 500-2000 and a hydroxyl group content of 1.7-6., 8, are used as the high molecular weight diol. %, or polydiene diol () with a content of hydroxyl groups of 38-0578% and a molecular weight of 4000-4300. The process for the preparation of liquid polyurethanes with terminal allyl groups can be represented by the following scheme

31

The structure of the polyurethanes obtained is confirmed by chemical analysis data (bromine number) and their molecular mass distribution data.

The resulting liquid polyurethanes are polymerized by a radical mechanism in the presence of radical type initiators, for example, methyl ethyl ketone peroxide, to form network elastic polymers having a higher tensile strength, hardness and lowered by: buoyancy in organic solvents.

Example 1. A three-neck round-bottomed flask equipped with a stirrer, a thermometer, and a tap to connect to a vacuum system is charged with 1000 ml of n-heptane, dissolved in it 174 mAh of 2,4-toluene diisocyanate at 20-25 ° C and added at stirring May 38 allyl alcohol. As it forms, the product precipitates, which is filtered off and washed repeatedly with n-heptane. The resulting product is a white crystal.

Solvent powder, soluble in organic solvents. To 33 ma.ch. of the resulting mono-derivative as a 25% solution in chloroform, 62.5 parts by weight were added with vigorous stirring. polyoxypropylene diol (content of hydroxyl groups 6.8%, molecular weight 500) with a ratio of NCO and OH groups of 1: 1, the catalyst — dibutyldyl-laurinate of tin in an amount of 0.05 wt.% of cass polyester. The reaction is stopped after the disappearance of the NCO-groups in the reaction mass (after 6 h). The resulting oligomer is planted in a 5-fold excess of n-heptane. The properties of polyurethane (D-ZTA) are presented in table. 2

Examples 2-4. According to the procedure described in Example 1, but using other diols, liquid polyurethanes with terminal allyl groups were obtained. Download the original components are given in table. 1. The properties of the obtained polyurethanes are given in table. 2-4.

Table 1

Polyurethane

High molecular weight

10TA

Polyoxypropylene, mol.mae. 1000, the content of OH groups of 3.4%

20TA

Polio zipropilendiol, they say. May 2000, the content of OH groups is 1.7%

BUT

Polydiol diol mol. May 4350, OH group content 0.78%

The synthesis is described in example 1.

Amount diol

2,4-toluene diisocyanate derivative,

parts by weight

123

33

250

33

543.7

33

Predlarae th way

table 2

Table 3

Polyurethane L. - Viscosity at, Properties of polymers obtained by 20 radical polymerization of liquid polyurethanes with terminal allylic

Continued table. 4 P; And - b1 ohm number, groups in the presence of methyl ethyl ketone peroxide, are presented in table. 5. ITABLE 5

9112127010

As can be seen from the above data, in addition to the proposed lyurethanes, which are spatially crosslinked to the prototype, the resulting radical method allows to obtain liquid polymerization of polyurethane and polyfetanes with aplil end oligomers with terminal endgroups that are distinguished by heightened orl groups, differ by (by 3.5-14.8%) content of allyl-enhanced tensile strength, groups, lower (by 12.5-49.5%) hardness and lowered toughness, and narrower p-ability in organic solution mass distribution leniem. Kromeritel x.

Claims (1)

METHOD FOR PRODUCING LIQUID POLYURETHANES WITH END ALYL GROUPS by interaction of 2,4- -toluylene diisocyanate, high molecular weight diol and allyl alcohol in an organic solvent medium, characterized in that, in order to increase the content of allyl groups, reduce the viscosity and polydispersity of liquid polyurethanes, they first carry out the interaction between 2,4-toluene diisocyanate and allyl alcohol at their equimolar ratio and then the interaction of the obtained product with a high molecular weight diol at an equivalent ratio of NC0 and OH groups.