JPH0633326B2 - Method for producing and separating chlorinated polydienes - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a chlorinated polydiene used as a main ingredient such as a lacquer, a paint, and an adhesive, and a method for separating the same.

[Conventional technology]

Chlorination of polydienes has been known for a long time and has been carried out on an industrial scale, and the obtained chlorinated rubber is used as a main raw material in the lacquer, paint, adhesive and printing ink industries. In addition, chlorinated rubber has excellent properties such that it can be dissolved in an inexpensive solvent, its solution is easy to apply, spray, dip, etc. and it dries quickly, and it is used as an extremely useful resin. In particular, in the paint field, it has become a resin that has been generally used as a paint for corrosion prevention, such as a ship paint, and as a paint for steel buildings such as long bridges and huge tanks. Conventionally, when chlorinating a polydiene, a method of chlorinating by contacting chlorine gas in a fine powder state (gas phase method), a method of directly contacting a raw material resin with chlorine gas in a heated and molten state to chlorinate ( (Melting method), a method of suspending a resin raw material in water to bring it into contact with chlorine gas for chlorination (aqueous suspension method), a method of contacting with chlorine gas dissolved in a halogen-based organic solvent (halogen) Organic solvent method) and the like are known. However, since the reaction temperature is high in the melting method, it is difficult to chlorinate the resin without discoloring it. In addition, since the resin is insoluble in water in the aqueous suspension method, uniform chlorination cannot be expected. From the viewpoint of uniform chlorination, the reaction in a halogen-based organic solvent can be said to be the most suitable method, but at present it is difficult to industrially use due to environmental problems. For example, JP-A-47-
10845 and JP-A-50-86698 describe a method for producing chlorinated amorphous polybutadiene. In these patents, it is stated that the reaction temperature is allowed up to 100 ° C. and it is desirable to use a catalyst such as ultraviolet rays in combination. However, under these conditions, even the solvent is chlorinated, and even substances that may destroy ozone are produced. Chloroform, tetrachloroethane, methylene chloride, etc. are said to be preferable as a solvent for chlorination, but it goes without saying that if these halogenated solvents remain in the product, a significant odor will be generated and the product value will be drastically reduced. Nor.

[Problems to be Solved by the Invention]

As described above, chlorinated polydiene is very effective as the main agent for lacquers, paints, and adhesives, but the conventional manufacturing method uses a halogen-based organic solvent such as carbon tetrachloride, which causes many environmental problems. .

As a result of intensive studies to solve environmental problems, the present inventors have as a by-product a substance that may cause environmental pollution by chlorinating a polydiene in an aliphatic saturated hydrocarbon solvent. The present invention has arrived at the present invention in which a chlorinated polydiene that is uniformly chlorinated without any chlorinated polydiene is produced, and then a chlorinated polydiene is taken out from the reaction solution as a solid.

A first object of the present invention is therefore to produce chlorinated polydienes without the use or by-products of substances which may cause environmental pollution.

The second purpose is to separate the resulting chlorinated polydiene from the reaction solution as a solid.

[Means for Solving the Problems]

The object of the present invention is to provide a polydiene without using a catalyst such as a photo-radical generator or the like without using by-product or using a substance that destroys ozone by chlorinating at low temperature in an aliphatic saturated hydrocarbon solvent. It has been found that a chlorinated polydiene is obtained.

The polydiene which is a raw material of the present invention is a polydiene which is liquid at room temperature and has a double bond in its structure. For example, 1,2-butadiene, 1,3-butadiene polymers or their copolymers can be exemplified. The aliphatic saturated hydrocarbon solvent may be a liquid at room temperature, preferably a linear one having 5 to 20 carbon atoms and containing no impurities such as cyclohexane. If toluene, benzene, or cyclohexane is used instead of the saturated aliphatic hydrocarbon solvent, benzyl chloride or chlorobenzene may be produced, which may cause environmental pollution. The reaction can be carried out at a concentration of 0.1 to 40% by weight and a reaction temperature of 40 ° C or lower, preferably 10 ° C or lower. Under this condition, the substitution reaction does not occur and only the addition reaction occurs selectively. At this time, if light or a radical generator is present, the solvent is also chlorinated. On the other hand, if the temperature exceeds 40 ° C., the resin that has begun to precipitate causes blocking, or the substitution reaction occurs at the same time as the addition reaction, and the solvent is chlorinated, which is not preferable. The reactor can be used as long as it is a container that blocks light and has cooling ability, but specifically, a glass-lined reaction container or the like is preferable. Stainless steel is not preferable because corrosion may occur and iron may act as a catalyst for promoting dehydrochlorination. The reaction of the chlorinated polydiene thus obtained proceeds, and precipitation starts when the degree of chlorination exceeds 35% by weight. The chlorinated polydiene thus deposited can be easily separated by suspending or precipitating in the reaction solution in the form of a fine powder to complete chlorination, and then filtering, centrifuging or decanting. Even after the initiation of precipitation, the addition of chlorine to the double bond is carried out very smoothly, and the degree of chlorination can be freely controlled up to an amount that can be theoretically calculated. Needless to say, the supply of chlorine can be stopped before precipitation occurs to obtain a low chlorinated product. Even if an attempt is made to chlorinate a liquid polydiene by an aqueous suspension method, the liquid polydiene does not disperse uniformly in water and causes blocking during the chlorination reaction to form a huge mass, which makes it impossible to uniformly chlorinate. Is. However, it is possible to obtain a highly chlorinated product by chlorinating in an aliphatic saturated hydrocarbon solvent and chlorinating at 40% by weight or more and then chlorinating by an aqueous suspension method. That is, if the polydiene is chlorinated and the softening point becomes room temperature or higher and then chlorinated by an aqueous suspension method, light is uniformly dispersed in water without causing blocking, or chlorine gas is used in combination with a radical generator or the like. It is also possible to chlorinate up to 70% by weight by blowing.

〔Example〕

Hereinafter, the present invention will be specifically described, but the present invention is not limited thereto.

Example 1 In a three-necked flask equipped with a stirrer, a cooling pipe and a gas introduction pipe, liquid polybutadiene (Nisso polybutadiene B-
100 g of 3000) was dissolved in 400 g of n-hexane. After the solution was uniformly dissolved, 100 g of chlorine gas was introduced into the solution over 10 hours while maintaining the system temperature at 0 to 3 ° C. and stirring. After the reaction, residual chlorine was purged with nitrogen gas for 2 hours.

The chlorinated polydiene deposited in the solution was filtered and separated, and then dried in a vacuum dryer at 60 ° C. for 2 hours. The reaction product was a white powder having a chlorination degree of 46% by weight. When a 20 wt% toluene solution was prepared from the obtained powder, it became a colorless and transparent viscous liquid.

Example 2 100 g of the chlorinated polydiene obtained in Example 1 was dispersed in 900 g of pure water in a three-necked flask equipped with a stirrer, and then the temperature of the system was kept at 90 ° C. while irradiating light with chlorine gas of 150 g.
g was introduced over 3 hours. The reaction product has a chlorination degree of 65.
It was a white powder of wt%. When a 20 wt% toluene solution was prepared from the obtained powder, it became a colorless and transparent viscous liquid.

Example 3 Liquid polybutadiene (Idemitsu Petroleum 4
5RHT) was chlorinated. The obtained reaction product was a white powder having a chlorination degree of 55% by weight. When a 20 wt% toluene solution was prepared from the obtained powder, it became a colorless and transparent viscous liquid.

Example 4 The chlorinated polybutadiene obtained in Example 3 was chlorinated in the same manner as in Example 2. The reaction product obtained is
It was a white powder having a chlorination degree of 60% by weight. When a 20 wt% toluene solution was prepared from the obtained powder, it became a colorless and transparent viscous liquid.

Example 5 20% by weight of the chlorinated polybutadiene obtained in Example 2,
Chlorinated paraffin 9% by weight, titanium dioxide 30% by weight,
A topcoat paint consisting of 1% by weight of epoxy resin and 40% by weight of xylene was prepared and applied onto a polished copper plate. After drying, make a cut that reaches the base on the coating surface and adhere 100 pieces of cross-cut tape to peel it in the direction of 180 degrees, then count the number of cross-cuts remaining, and it will not come off as one showed that.

Example 6 The gloss retention was 90% or more after the topcoat paint prepared in Example 5 was applied on a polished copper plate and then tested with a sunshine weather meter for 500 hours.

Comparative Example 1 In a three-necked flask equipped with a stirrer, a cooling pipe and a gas introduction pipe, liquid polybutadiene (Nisso polybutadiene B-
100 g of 3000) was dispersed in 400 g of pure water. After uniformly dispersing, 100 g of chlorine gas was introduced into the solution by stirring for 10 hours while keeping the temperature of the system at 0 to 3 ° C. After 30 minutes, it became a huge lump and wrapped around the stirring blade. After the reaction, residual chlorine was purged with nitrogen gas for 2 hours. The obtained product was a white block and had a chlorination degree of 14% by weight.

Comparative Example 2 In a three-necked flask equipped with a stirrer, a cooling pipe and a gas introduction pipe, liquid polybutadiene (Nisso polybutadiene B-
100 g of 3000) was dissolved in 90 g of carbon tetrachloride. After uniform dissolution, 200 g of chlorine gas was introduced into the solution over 10 hours while irradiating with light while maintaining the system temperature at 65 ° C. After the reaction, residual chlorine was purged with nitrogen gas for 2 hours. To take out chlorinated polybutadiene in carbon tetrachloride, toluene substitution was carried out to obtain a 20% by weight colorless and transparent viscous liquid. The degree of chlorination was 65% by weight.

〔The invention's effect〕

The polydiene chlorination production method and separation method of the present invention,
Since chlorination is carried out in an aliphatic saturated hydrocarbon solvent while cooling in a catalyst-free manner, a chlorinated polydiene can be obtained without by-products which may pollute the environment. Further, since it can be easily taken out as a fine powder after chlorination, there is an advantage that it is not necessary to perform a complicated process such as toluene replacement.

Claims (4)

[Claims] 1. A process for producing a solvent-soluble chlorinated polydiene, which comprises uniformly chlorinating a polydiene in an aliphatic saturated hydrocarbon solvent in the absence of a catalyst at 40 ° C. or lower. 2. The method for producing a chlorinated polydiene according to claim 1, wherein the degree of chlorination is 0.1 to 55% by weight. 3. A method for separating a chlorinated polydiene, which comprises depositing the chlorinated polydiene according to claim 1 or 2 having a chlorination degree of 35 to 55% by weight from a reaction solution. 4. A solvent-soluble chlorination degree of 55 to 70% by weight, characterized in that the separated chlorinated polydiene according to any one of claims 1 to 3 is further chlorinated in an aqueous suspension.
Method for producing chlorinated polydiene.