JPH0713112B2 - Method for producing triallyl isocyanurate polymer composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a triallyl isocyanurate polymer composition. More particularly, it relates to a method for producing a composition having a triallyl isocyanurate polymer dissolved in triallyl isocyanurate, which is useful as a crosslinking agent for rubber, plastics and the like.

(Prior Art and Problems) Triallyl isocyanurate is widely used as a cross-linking agent for rubber, plastics, etc., and its heat resistance,
It is known to be useful for improving chemical resistance, hydrolysis resistance, mechanical properties, weather resistance and the like.

However, since triallyl isocyanurate is liquid at room temperature and has relatively poor compatibility with rubber and plastics, when triallyl isocyanurate is used as a crosslinking agent for rubber and plastics, etc. In the step of prepreg or the step of prepreg, a so-called bleeding phenomenon in which triallyl isocyanurate oozes out on the surface, which hinders workability such as handling and also has a problem in uniformly crosslinking the material, and improvement is required. Was there.

This bleeding phenomenon can be reduced or overcome by using a part of triallyl isocyanurate as a polymer, that is, by using the triallyl isocyanurate polymer dissolved in triallyl isocyanurate.

As a polymerization method of triallyl isocyanurate, a method of heating in the presence of a radical initiator (Japanese Patent Publication No. 357835),
Alternatively, a method of emulsion polymerization in the presence of a radical initiator (US Pat. No. 3,576,789) is known. But,
The polymers obtained by these methods are insoluble not only in triallyl isocyanurate but also in other organic solvents, and are not suitable as a crosslinking agent.

Further, triallyl isocyanurate is polymerized in the presence of a radical initiator in an organic solvent having a relatively large chain transfer constant, and the reaction solution is charged into an organic solvent in which triallyl isocyanurate is dissolved but the polymer is not dissolved. There is also known a method of separating the polymer by the method described in JP-A-48-54192.
Japanese Patent Publication No. 50-11435).

According to this method, a solvent-soluble polymer can be obtained, and a crosslinking agent composition having a desired polymer content can be obtained by dissolving the polymer in triallyl isocyanurate. However, since the reaction solvent acts as a chain transfer agent and is bonded as a molecular weight modifier to the polymer obtained by the above method, it cannot be said to be a homopolymer of triallyl isocyanurate. From an industrial point of view, in addition to using a large amount of organic solvent for the polymerization reaction and separation of the polymer from the reaction solution to obtain the polymer, separation of unreacted triallyl isocyanurate from the polymer, radical initiation It is not a preferable method because it requires complicated steps such as removal of the agent.

(Means for Solving Problems) The present inventors have studied the method for producing a composition in which a triallyl isocyanurate polymer is dissolved in triallyl isocyanurate, and have achieved the present invention. In the presence of molecular oxygen, triallyl isocyanurate is heated to 100 ° C. or higher to partially polymerize it, and then the triallyl isocyanurate polymer is dissolved in triallyl isocyanurate. And a method for producing the composition.

According to the theory of polymerization of allyl compounds described in Chemical Review, Vol. 5, pp. 807-843 (1958), molecular oxygen generally acts as a disturbing agent for polymerization of allyl compounds.

However, according to the study by the present inventors, it was found that triallyl isocyanurate is rapidly polymerized when heated to 100 ° C. or higher in the presence of molecular oxygen. Moreover, it is extremely easy to take a three-dimensional structure in the process of polymerization,
As a result, insoluble, from a polyfunctional triallyl isocyanurate that tends to produce an infusible gel, despite not using a chain transfer agent according to the method of the present invention, an insoluble, without producing an infusible gel, The selective formation of a polymer soluble in triallyl isocyanurate is surprising.

The present invention will be specifically described below.

According to the method of the present invention, triallyl isocyanurate is heated to a temperature of 100 ° C. or higher in the presence of molecular oxygen to cause a polymerization reaction. This reaction can be carried out under normal pressure or under pressure. As the molecular oxygen, oxygen gas or an oxygen-containing gas such as air is used. The supply amount of molecular oxygen varies depending on its form, supply method, polymerization temperature and the like, and cannot be unconditionally specified.

The polymerization temperature needs to be 100 ° C. or higher, and at a temperature lower than 100 ° C., the polymerization reaction does not substantially proceed even in the presence of molecular oxygen. Moreover, the upper limit of the polymerization temperature is not particularly limited, but at a temperature of 180 ° C. or higher, the polymerization reaction proceeds rapidly, and it becomes difficult to control the polymerization rate. Usually 110-1
A range of about 60 ° C is preferable.

The progress of the polymerization reaction can be traced by checking the viscosity or the refractive index of the reaction solution against the calibration curve of the viscosity or the refractive index of the polymerization reaction solution and the polymerization rate which is prepared in advance. When the polymerization rate reaches a predetermined value, the polymerization reaction is stopped, but if the supply of oxygen is stopped and the temperature is lowered to less than 100 ° C, the reaction is stopped immediately. In the present specification, the polymerization rate is% by weight of the amount of the polymer in the polymerization reaction liquid, and the amount of the polymerization is 1 part by weight of the polymerization reaction liquid in 5 parts by weight of methanol with vigorous stirring to cause precipitation. The thus obtained methanol insoluble matter was collected by filtration, washed twice with 5 parts by weight of methanol, and then vacuum dried at 60 ° C. to be obtained.

In the present invention, the polymerization reaction is usually allowed to proceed until the polymerization rate reaches 5% or more. A reaction liquid having a polymerization rate of less than 5%, that is, a composition comprising a polymer of less than 5% and triallyl isocyanurate, when used as a crosslinking agent for rubber or plastics, bleeds triallyl isocyanurate from a compound or prepreg. The suppression effect is relatively small.

As the polymerization rate of the reaction solution increases, the bleeding suppressing effect when it is used as a crosslinking agent also increases. But,
If the polymerization rate is too high, the reaction solution gels and becomes unsuitable as a crosslinking agent. Usually, the polymerization is stopped before the rate of polymerization reaches 35%.

Although a polymerization inhibitor is usually added to triallyl isocyanurate for the purpose of stabilizing storage, it can be used in the method of the present invention without being particularly removed.

(Effect of the Invention) According to the method of the present invention, isocyanuric acid useful as a cross-linking agent for rubber, plastics, etc. by an extremely simple method without using an organic solvent or a radical initiator and at low cost. A composition in which the triallyl polymer is dissolved in triallyl isocyanurate can be obtained.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Example 1 Volume 50 equipped with stirrer, thermometer, gas inlet pipe and exhaust port
During reactor 0 ml, 50 ppm of 3,5-Sita - Chari - triallyl isocyanurate containing butyl-4-hydroxytoluene (antioxidant) (refractive _{^{index: ▲ n 30 D ▼ 1.5095)}} 300g
Was charged and heated to 145 ° C. with stirring, and the polymerization reaction was carried out at the same temperature while introducing 50 ml of air per minute through a gas introduction tube.

During the reaction, a part of the reaction solution was sampled, the reaction was continued while measuring the refractive index at 30 ° C using an Appe refractometer, and the polymerization rate was calculated from the calibration curve of the refractive index and the polymerization rate created in advance.
% Refractive index: n ³⁰ _D At the time of 1.5230, the air supply was stopped and the mixture was cooled to obtain a composition in which the triallyl isocyanurate polymer was dissolved in triallyl isocyanurate.

A part of this composition was taken and the polymerization rate was measured to be 25.4%.

The polymer thus obtained is acetone, methyl ethyl ketone, benzene, toluene, xylene, dichloromethane, carbon tetrachloride, tetrahydrofuran, N, N.
-A gel-free polymer that is completely dissolved in dimethylformamide and the like, and the weight average molecular weight measured by GPC method was 203,000 in terms of polystyrene.

Example 2 The reactor of Example 1 was charged with 300 g of triallyl isocyanurate used in Example 1, and the polymerization reaction was carried out at 120 ° C. while introducing 250 ml of air per minute with stirring. During the reaction
As in the case of Example 1, a part of the reaction solution was sampled, the reaction was continued while measuring the refractive index at 30 ° C., and a refractive index of 10% was calculated from the calibration curve of the refractive index and the polymerization rate prepared in advance. At the time when the value reached: (n ³⁰ _D) 1.5144, the air supply was stopped and the mixture was cooled to obtain a composition in which the triallyl isocyanurate polymer was dissolved in triallyl isocyanurate. A part of this composition was taken and the polymerization rate was measured and found to be 10.3%.

The polymer thus obtained is acetone, methyl ethyl ketone, benzene, toluene, xylene, dichloromethane, carbon tetrachloride, tetrahydrofuran, N, N.
-A gel-free polymer completely soluble in dimethylformamide and the like, and the weight average molecular weight measured by GPC method was 7,800 in terms of polystyrene.

Claims (5)

[Claims] 1. In the presence of molecular oxygen, triallyl isocyanurate is heated to 100 ° C. or higher to partially polymerize it.
Then, a method for producing a composition in which a triallyl isocyanurate polymer is dissolved in triallyl isocyanurate, which comprises terminating the polymerization. 2. The method for producing the composition according to claim 1, wherein the polymerization reaction is allowed to proceed until the degree of polymerization reaches 5% or more. 3. The method for producing the composition according to claim 1, wherein the polymerization reaction is stopped before the reaction solution gels. 4. The method for producing a composition according to claim 1, wherein the polymerization reaction is stopped before the degree of polymerization reaches 35%. 5. A polymerization reaction is carried out while introducing an oxygen-containing gas into the reaction solution, and when the polymerization rate reaches a predetermined value, the supply of the oxygen-containing gas is stopped and the reaction solution is cooled to carry out the polymerization. Claim 1 characterized in that the reaction is stopped
Item 5. A method for producing the composition according to any one of Items 4 to 4.