JPS6142504A - Production of epoxidized polymer - Google Patents

Abstract

PURPOSE:To produce the titled polymer excellent in weather and heat resistances and suitable for use in adhesives, sealing agents, paints, etc., without side reactions such as gelation, by reacting hydrogenated polyisoprene with an epoxidizing agent. CONSTITUTION:In the production of an epoxidized polymer by reacting polyisoprene with an epoxidizing agent, hydrogenated polyisoprene of a rate of hydrogenation of 30-95% is used as said polyisoprene. It is preferable that the polyisoprene before hydrogenation has a MW of 5,000-150,000. Because the hydrogenation and the epoxidation can proceed without side reactions such as gelation, it is possible to obtain an epoxidized polymer easily at a high conversion in high yields.

Description

[Detailed description of the invention]! The present invention relates to a method for producing an epoxidized polymer. More specifically, the present invention relates to a method for producing an epoxidized polymer by reacting a hydrogenated polyisoprene with an epoxidizing agent.

Conventional technology Conventionally, a portion of the carbon-carbon double bonds in polyisoprene are converted into epoxy groups using an epoxidizing agent, and the resulting nine-epoxidized polymer is treated with a catalyst such as Raney nickel or carbon-supported platinum catalyst. Hydrogenation using a homogeneous catalyst or a homogeneous catalyst such as a Ziegler catalyst is described, for example, in JP-A-56
It is known from the publication No.-127641.

Departure F! Problem A aims to solve However, when hydrogenating an epoxidizing agent as described above, when a heterogeneous catalyst is used as a catalyst in the hydrogenation reaction, the epoxidized polymer is adsorbed on the catalyst surface. The ash rate of hydrogenation is extremely slow and the catalyst is extremely difficult to remove from the reaction solution. Also,
When a homogeneous catalyst is used, the epoxy groups in the epoxidized polymer react with each other during the hydrogenation reaction, resulting in a significant increase in the viscosity of the reaction system, or in severe cases, gelation, which prevents the hydrogenation reaction from proceeding. do not.

The purpose of the present invention is to
The object of the present invention is to provide a method for producing an epoxidized polymer from polyisoprene in high yield.

Another object of the present invention is to provide a method for producing an epoxidized polymer that has excellent weather resistance and heat resistance without impairing the inherent properties of the epoxidized polymer.

In producing an epoxidized polymer by reacting with - Oboro ■, the polyisoprene has a hydrogenation rate of 30 to 9.
This is accomplished by using a 5-inch polyisoprene hydrogenate.

The hydrogenated polyisoprene used in the production method of the present invention is obtained by hydrogenating polyisoprene in a conventional manner.

The above polyisoprene before hydrogenation (hereinafter also referred to as unmodified polyisoprene) has a molecular weight of 5,000 to 1
It is desirable to have a molecular weight within the range of 50,000.

If the molecule t is too small, the strength of the finally obtained epoxidized polymer will be insufficient when used as an adhesive or coating material. On the other hand, if the molecular weight is too large,
The viscosity of the reaction system during the hydrogenation reaction and epoxidation reaction is too strong, making it difficult for the reaction to proceed, and the viscosity of the epoxidized polymer ultimately obtained is too high, making it difficult to handle. It is inconvenient when handling or using it.

The molecular weight here means the viscosity average molecule t (MY), which is the intrinsic viscosity at 30°C in toluene solution ((
77)), and formula (17) = 1. ! IX
10-4 MY
No. 102938 It is desirable that the content is 50% or less. If the amount of vinyl bonds exceeds 50%, it is not preferable because a flexible molded article cannot be manufactured using the epoxidized polymer finally obtained.

Such unmodified polyisoprene can be obtained by polymerizing imprene monomers or by decomposing high molecular weight polyisoprene. Among these, since the molecular weight can be easily adjusted, the vinyl bond content of polyisoprene obtained by anionic polymerization using an anionic polymerization initiator and living polymerization using a lithium-based polymerization initiator falls within the above-mentioned desirable range. Therefore, Q is most preferably adopted.
The gist of the present invention is to hydrogenate the double bonds of the polyisoprene and then subject it to an epoxidation reaction.

Hydrogenation of polyisoprene includes a method in which molecular hydrogen is brought into contact with polyinoprene in the presence of an insoluble solvent using a heterogeneous catalyst made of a metal such as nickel, platinum, or palladium or a Ziegler-based homogeneous catalyst. The reaction temperature at that time is 0 to 300°C, the hydrogen pressure is 1 to 500 atm, and the reaction time in the hydrogenation reaction under these conditions is 0.1 to 10 hours. Examples of the solvent used in the reaction include hexane, heptane, toluene, and xylene. The production of polyisoprene is 30% by weight.
Although it can be made as high as 5 to 20 weights, it is usually preferred.

In the present invention, the hydrogenation rate in the hydrogenated polyurethane, that is, the carbon-
The proportion of hydrogenated double bonds to carbon unsaturated double bonds is in the range 50-95%. If the hydrogenation rate is too small, the proportion of remaining double bonds will be too high.
When made into an epoxidized polymer, the weather resistance and heat resistance are not sufficiently improved, which is undesirable. On the other hand, if the hydrogenation rate is too high, the reaction rate during the epoxidation reaction will be extremely slow and the amount of epoxy groups introduced into the molecule will be too small. Furthermore, the effect of improving physical properties based on the epoxy groups of the resulting epoxidized polymer becomes insufficient.

The epoxidation reaction is carried out by adding an epoxidizing agent to polyisoprene and heating it, or by using a combination of compounds that can act as an epoxidizing agent in the reaction system and heating it. Typical epoxidizing agents include organic peracids such as peracetic acid, perpropionic acid, and perbenzoic acid, t-butyl hydroperoxide, cumene hydroperoxide,
Examples include organic hydroperoxides such as diisoglobenylbenzene peroxide. Two compounds that can serve as epoxidizing agents include a combination of a carboxylic acid such as formic acid, acetic acid, or propionic acid and hydrogen peroxide. Although this reaction can be carried out in the absence of a solvent, it is preferably carried out in the presence of a solvent that is inert to the epoxidizing agent and the like. Preferably, the solvent is an aliphatic hydrocarbon such as hexane or heptane, an aromatic hydrocarbon such as benzene or xylene, or a halogenated hydrocarbon such as chloroform or carbon tetrachloride. The amount varies depending on the degree of epoxidation and reaction conditions, but is preferably within the range of 0.1 to 10 equivalents relative to the double bond in the hydrogenated polyisoprene. The reaction temperature is preferably within the range of 0 to 20°C, but when using organic peroxides as the epoxidizing agent, a higher temperature is required; When using other epoxidizing agents, the temperature is preferably within the range of 20 to 120°C.
The reaction time varies depending on the amount of epoxidizing agent used, the reaction temperature, etc., but is usually within the range of 0.5 to 10 hours.

The ratio of epoxy groups converted from carbon-carbon unsaturated double bonds in the epoxidized polymer of the present invention is the molar ratio to the carbon-carbon unsaturated double bonds in unmodified polyisoprene (hereinafter referred to as epoxidation rate). ) is within the range of 0.2 to 70%. If the epoxidation rate is too low, sufficient crosslinking will not be formed when the epoxidized polymer is crosslinked with a crosslinking agent, making it impossible to use it as a sealing material, coating material, etc. On the other hand, the epoxidation rate does not exceed 70% due to the relationship with the hydrogenation rate. From this point of view, the jepoxidation rate is preferably 5 to 50%.

Action In the present invention, how the hydrogenated polyisoprene and epoxidizing agent act in the reaction system,
Its mechanism of action itself is not clear. However, as shown in the above-mentioned Japanese Unexamined Patent Publication No. 56-127641, when a hydrogenation reaction is performed after an epoxidation reaction, the catalyst used for hydrogenation is The epoxy groups in the epoxidized polymer react in a complex manner to form intramolecular or intermolecular crosslinks in the epoxidized polymer. The hydrogenation reaction is carried out in the absence of active groups, and during the epoxidation reaction, there are few carbon-carbon unsaturated double bonds, and there are other groups that can easily react with the epoxidizing agent. Therefore, it is expected that the epoxidation reaction will proceed easily.

Effects of the Invention In the production method of the present invention, the hydrogenation reaction and the epoxidation reaction proceed without accompanying side reactions such as gelation. Therefore, combined with a high reaction rate, an epoxidized polymer can be easily obtained at a high yield.In addition, the resulting epoxidized polymer does not contain gels or impurities, and has few residual double bonds, so it has good weather resistance and It has excellent heat resistance and also shows high reactivity due to the introduced epoxy group. Therefore, as well as polyhydric compounds with low molecular weight and low epoxy value, amines such as diethylenetriamine, metaphenylenediamine, and tris(dimethylaminemethyl)phenol, carboxylic acids such as phthalic acid, cono-phosphoric acid, and their anhydrides, Crosslink with its anhydride, polyamide resin, boron trifluoride complex, etc. Taking advantage of these features, the present invention is suitably used for applications such as adhesives, sealants, coating materials, paints, etc.Examples The present invention will be specifically explained using Examples below, but the present invention is not limited by them in any way. It is not something that can be done.

Example 1 Molecular weight: 19,000, obtained by solution polymerization using n-butyllithium as a catalyst. Low molecular weight polyisoprene 1002 with vinyl bond content of 21 and cyclohexane 40
After charging 01 into an autoclave and dissolving it, a carbon-supported baladicium catalyst (palladium: 5% by weight) was added and dispersed, and the mixture was pressurized to 35 KP/- by hydrogen gas. Next, a hydrogenation reaction was carried out at 50° C. with stirring. reaction 1
After an hour, the mixture was cooled to room temperature, residual hydrogen was released, and the reaction was stopped. The catalyst was removed from the reaction mixture by filtration and dried under vacuum to obtain a hydrogenated product of polyisoprene.

The hydrogenation rate determined by infrared spectroscopy was 59%. The hydrogenated material 602 is dissolved in toluene 100fK,
101 of formic acid was added, the temperature was raised to 50°C, and while maintaining this temperature, 100 tons of hydrogen peroxide solution (30% by weight) was added dropwise over about 1 hour to carry out an epoxidation reaction. After the dropwise addition was completed, the mixture was kept at 50° C. for 1 hour, and then the aqueous layer was separated, the organic layer was washed with water, and the product was taken out by vacuum drying. When the product was examined by infrared spectroscopy, the epoxidation rate was 32.
It was a modified polyisoprene with a hydrogenation rate of 59%.

Add 5 parts by weight of tris(dimethylaminomethyl)phenol to 100 parts by weight of the above modified polyisoprene, then apply the mixture to a glass plate so that the thickness of the dry curing agent is 1 layer, and heat at 120°C for 2 hours. A cured film was created by heating. The weather resistance of the cured film was examined using a medium senone weather meter, and no change was observed in the cured film even after 500 hours of irradiation.

Further, 100 parts by weight of the above modified polyisoprene, 130 parts by weight of anhydrous methylnazic #1 and 1 part by weight of tris(dimethylaminomethyl)phenol were mixed, poured into a Teflon-coated metal frame, and heated at 150°C for 30 minutes to form a cured molded product. The resulting molded product was heated in a gear oven at 180° C. for 1 hour, but no change was observed in the surface condition or shape of the molded product.

Comparative Example 1 Epoxidation was carried out in the same manner as in Example 1, except that in the epoxidation reaction of Example 1, the unmodified polyisoprene used in Example 1 before hydrogenation was used instead of the hydrogenated polyisoprene. Epoxidized polyisoprene having a ratio of 36 mol was obtained. This reaction was repeated twice to obtain about 3252 epoxidized polyisoprene.

In the hydrogenation reaction of Example 1, the hydrogenation reaction was carried out in the same manner as in Example 1, except that the above-mentioned epoxidized polyisoprene was used in place of the non-hydrogenated unmodified polyinoprene, and the reaction time was changed to 2 hours. However, hydrogen absorption was extremely slow, and the hydrogen pressure in the system stopped decreasing one hour after the start of the reaction. Two hours after the reaction had started, the reaction was stopped and an attempt was made to separate the catalyst from the reaction mixture, but the reaction mixture was so viscous that it was extremely difficult to filter it.

When we examined the barely obtained reaction product, we found that the residual rate of double bonds was 45%, the hydrogenation rate was 19%, and the epoxidation rate was 3.
The material was 67 Ru0 modified polyisoprene.

A cured film and a cured molded product were prepared from the above modified polyisoprene in the same manner as in Example 1, and the weather resistance and heat resistance were examined using a xenon weather meter and with the gear open at 180°C. After 300 hours of irradiation, the cured film A thin cured film separated from the surface, and cracks appeared on the surface after 500 hours of irradiation. Further, the surface of the cured molded product showed some stickiness after 30 minutes of heating, and the surface was washed away after 1 hour of heating.

Example 2 Molecule! 52,000. Polyisoprene 100f'e with a vinyl bond content of 16% is dissolved in hexane, charged into an autoclave, and then added to cobalt naphthenate and 0.1 mol per 100 isoprene monomer units in the trieboline. and pressurized with hydrogen at 10 Kp/mK,
After the hydrogenation reaction was completed at 50°C, the resulting product was examined by infrared spectroscopy, and it was found that a hydrogenated polyisoprene product with a hydrogenation rate of 72% was obtained. It turns out.

The above hydrogenated product 60F was dissolved in toluene 100F, 10f of formic acid was added, the temperature was raised to 50°C, and while maintaining this temperature, 30% by weight hydrogen peroxide solution 100V was added dropwise over about 1 hour to initiate the epoxidation reaction. I did it. After the dropwise addition was completed, the mixture was kept at 50°C for an additional hour, and then the aqueous layer was separated, the organic layer was washed with water, and the product was filtered out by vacuum drying. When the product was examined by infrared spectroscopy, it was found that the hydrogenation rate was 7.
It was found that modified polyisoprene with an epoxidation rate of 21% was obtained.

When the weather resistance of the modified polyisoprene was examined in the same manner as in Example 1, no change in condition was observed even after irradiation with a xenon weather meter for 9,500 hours.

Claims (2)

[Claims] (1) An epoxidized polymer characterized in that when producing an epoxidized polymer by reacting polyisoprene with an epoxidizing agent, a hydrogenated polyisoprene with a hydrogenation rate of 30 to 95% is used as the polyisoprene. manufacturing method. (2) The molecular weight of polyisoprene before hydrogenation is 5
,000 to 150,000.