JP2715245B2 - Manufacturing method of chlorinated rubber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chlorinated rubber widely used for heavy-duty anticorrosive paints, inks and adhesives for outdoor buildings and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Chloride rubber is a resin obtained by chlorinating natural rubber or synthetic rubber (polyisoprene) until the chlorine content exceeds 60%. It is chemically stable, resistant to acids and alkalis, and weather resistant. Excellent, easily soluble in aromatic solvents such as toluene and organic solvents such as esters and ketones. For this reason, it is used in paints, inks and adhesives, especially in heavy anticorrosion paints, etc., and has been industrially manufactured since ancient times.

At present, in order to produce chlorinated rubber industrially,
Raw materials such as natural rubber and synthetic rubber are dissolved in carbon tetrachloride, which is a chlorine-based solvent inert to chlorine, and chlorination is performed by passing chlorine gas through this solution. Although a large amount of carbon tetrachloride is used in the solution method, it is difficult to completely recover carbon tetrachloride at low cost, and some of the carbon tetrachloride leaks from manufacturing equipment and volatilizes into the atmosphere, or is mixed in small quantities into products. Was. However, carbon tetrachloride is harmful to the human body, and its use has been decided worldwide to destroy the ozone layer. Also,
Chlorine-based organic solvents such as chloroform have problems in toxicity and reactivity with chlorine, and cannot be used as a solvent in place of carbon tetrachloride.

[0004]

Attempts have been made to chlorinate natural rubber latex as a chlorination method completely different from the solution method. This method
A surfactant and acid are added to natural rubber latex to prevent coagulation of the latex and chlorinate by blowing chlorine gas (British Pat. 634241 (1947), Industrial
and EngineeringChemistry, Vol. 43, p. 2535 (195
1)). However, these methods have a disadvantage that the progress of the reaction is extremely slowed in the latter half of the chlorination reaction, and that a product having a high chlorine content cannot be obtained. Therefore, in order to solve this problem, the present applicant has developed a method of performing a chlorination reaction in two stages consisting of specific temperature conditions and ultraviolet irradiation conditions (Japanese Patent Laid-Open Publication No.
No. 59801).

In this method, although the chlorination reaction proceeds, the reaction rate becomes slightly slower when the chlorine content is about 63% or more, and the viscosity of the system extremely increases in the latter half of the reaction. The following fine particles are disadvantageous in that they have poor dehydration properties in the post-process after chlorination, and that the dry powder of the chlorinated rubber is fine particles, so that handling is poor.

[0006]

The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, if the temperature is raised to a temperature higher than the softening temperature of the conventional resin, the resin aggregates and the continuation of the reaction becomes difficult. Surprisingly, by raising the temperature under specific conditions, the resin becomes several tens of μm
It has been found that the particles can be uniformly agglomerated to the size of to improve operability and reactivity, and the present invention has been accomplished. That is, in a chlorinated rubber obtained by adding a surfactant and an acid to a rubber latex and chlorinating a chlorine gas in an aqueous medium to a chlorine content of 60% to 75% with chlorine gas, after the chlorine content exceeds 50% It has been found that the above problem can be solved at least once by raising the temperature of the reaction system to a temperature higher than the softening start temperature of the resin and performing chlorination.

[0007] The rubber latex in the present invention refers to natural rubber latex, synthetic polyisoprene rubber latex, polybutadiene latex, SBR latex, polychloroprene latex, and the like, and includes synthetic diene rubber latex in addition to natural rubber latex. Of these, natural rubber latex and synthetic polyisoprene rubber latex are preferred because of their high industrial value.

As the natural rubber latex, a high ammonia type or a low ammonia type concentrated by a centrifugal separation method is generally used.
A special type treated with a chemical, or a latex by a creaming method or an evaporation method may be used. The natural rubber latex may be used as it is, or may be depolymerized to adjust the molecular weight. For the depolymerization, an oxidative method using oxygen or hydrogen peroxide or a method using a radical generator such as peroxide is used (adhesion, vol. 31, p. 308 (1987)).

The synthetic polyisoprene rubber latex can be produced by emulsion polymerization according to a known method ("Overview of Synthetic Rubber" p.130, Asakura Shoten (1971)). Further, a solution-polymerized polyisoprene is post-emulsified and the solvent is removed (manufactured by Sumitomo Seika Co., Ltd., trade name: Maxprene IR-900);
What emulsified liquid polyisoprene may be used. In addition, a latex in which a polar group is introduced by graft modification of a natural rubber latex, and a synthetic polyisoprene rubber latex in which a polar monomer is copolymerized can also be used.

The method of chlorinating rubber latex can be carried out by a known method described below (for example, JP-A-4-59801). If chlorine gas is blown directly into the rubber latex, the latex solidifies and cannot be chlorinated. This is because the latex is anionic, and when chlorine gas is blown, hypochlorous acid or hydrochloric acid is generated and the latex is destroyed. Therefore, a nonionic surfactant or a cationic surfactant is added to the rubber latex before chlorination. By performing this treatment, even if chlorine gas is blown into the rubber latex, the latex does not coagulate and chlorination can be performed.

The amount of the nonionic or cationic surfactant is preferably 0.5% to 10% based on the solid content of the latex. If it is less than 0.5%, the coagulation of the latex cannot be prevented. Does not improve. More preferably, it is 2% to 5%.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ester, sorbitan alkyl ester, polyoxyethylene sorbitan alkyl ester, and the like. And quaternary ammonium salts thereof, aromatic quaternary ammonium salts, and heterocyclic quaternary ammonium salts.

Before the chlorination, an acid is added to the latex.
This is to prevent hydroxylation to a double bond in the isoprene structure, and has the advantage of improving the solubility of chlorine in an aqueous solution and, in the case of natural rubber, improving the stability of the latex. The concentration of the acid is 0.1N or more, preferably 3N or more, more preferably 6N or more. If the acid concentration is too high, a side reaction may occur, so the upper limit is preferably about 8N. Examples of the acid used include hydrochloric acid and sulfuric acid, and hydrochloric acid is preferred.

Preferably, chlorination is performed at a temperature of 50 ° C. or less at the beginning of the chlorination reaction. If the temperature is too high in the initial stage, a large solidified product is easily formed, which is not preferable. Also,
In the initial stage, the reaction rate is high and heat is generated, so the temperature is more preferably 30 ° C. or lower. At this stage, since the reaction proceeds without a catalyst such as light, light irradiation does not need to be performed.

When the chlorine content reaches 30% or more, it is preferable to gradually increase the temperature and proceed with chlorination. From this stage, it is preferable to chlorinate while irradiating ultraviolet rays,
Chlorination can proceed without UV irradiation.

When the chlorine content is high, the rubber particles lose elasticity and become resin and become hard. In particular, when the chlorine content exceeds 50%, the softening temperature of the resin becomes considerably high.

Although the softening temperature of the resin has a width due to non-uniformity, in the present invention, the softening temperature is represented by the softening start temperature (the lowest point of the softening temperature). The softening start temperature is DS
It can be measured by C (differential scanning calorimetry). DS
When measuring the softening temperature of the resin in C, the softening start temperature means the temperature at which the endothermic peak rises. The softening start temperature varies depending on the molecular weight, but is 50 to 80 ° C at a chlorine content of 50% and 80 to 110 ° C at a chlorine content of 60%.

When the temperature is increased in a place where the chlorine content is low, a large coagulated product is formed and the reaction cannot be continued. Surprisingly, in a place where the chlorine content is high, the particles are uniformly aggregated and the particles are thermally fused. Thus, large particles having a uniform particle diameter can be generated. For this reason, after the chlorine content exceeds 50%, the reaction can be continued while raising the temperature to a temperature higher than the softening start temperature of the resin to enlarge the particles. The reaction temperature at this time is preferably 1 to 20 ° C. higher than the softening start temperature, and more preferably 3 to 10 ° C. higher. If the temperature is too high, the resin is undesirably colored.

In the method of raising the reaction temperature to a temperature higher than the softening start temperature, the temperature may be once raised to a temperature higher than the softening start temperature and then lowered, or the temperature may always be kept higher than the softening start temperature. . Preferably, the chlorination is carried out by increasing the chlorine content to more than 90 ° C after the chlorine content exceeds 58%. Further, it is preferable to increase the chlorine content to more than 100 ° C. under pressure after the chlorine content exceeds 61%. The upper limit of the temperature is preferably 180 ° C. or lower, more preferably 150 ° C. or lower, even in a place where the chlorine content is high in order to prevent decomposition of the resin. Further, when chlorinating at a high temperature of 100 ° C. or higher, there is an advantage that chlorination proceeds rapidly without a catalyst such as light.

When the temperature is raised to a temperature higher than the softening start temperature of the resin in this way, the particles aggregate and become larger, but the particle size varies depending on the width of the temperature raised above the softening start temperature and the time during which the temperature is raised. Therefore, when the reaction concentration and the number of rotations of stirring are constant, the particle diameter can be controlled by controlling the temperature and time. At this time, it is necessary to perform appropriate stirring, and it is desirable that the stirring be performed at least at 10 rpm or more, and more preferably 30 rpm or more.
Usually, it is preferable to make particles having a size of 5 μm or less into a size of 10 μm or more. More preferably, the size is 20 μm or more. If the particle diameter is too large, the reactivity of chlorination decreases. Therefore, the particle diameter is desirably 200 μm or less. The particle diameter can be measured by an optical method utilizing a laser diffraction phenomenon, and is represented by an average particle diameter. In this case, the measurement is performed after the measurement sample is sonicated to loosen loose aggregation. 150
The measurement is performed after irradiating ultrasonic waves with an output of W or more for 1 minute or more.

The latex concentration in the chlorination reaction is 1
% To 10% is preferable. If it is 10% or more, the viscosity becomes too high in the latter half of the chlorination reaction, and the reaction efficiency decreases. If it is 1% or less, the productivity is poor.

The reactor for chlorination can be carried out in a pressurized reaction tank equipped with a stirrer and a jacket, the inside of which is glass-lined. Chlorine gas is blown from the bottom of the reactor or the space above the reactor. The reaction may be carried out at normal pressure, but when the temperature is raised to 100 ° C. or higher, it is necessary to carry out the reaction under pressure.

In the present invention, if the stirring in the reaction vessel is insufficient, uniform aggregation may not occur. Therefore, it is desirable to use a device capable of appropriately stirring. When irradiating with ultraviolet light, a mercury lamp, a carbon arc lamp, a discharge tube of a rare gas and the like can be used as a light source, but a high-pressure mercury lamp is preferable and used by being incorporated in a reactor.

The depolymerization treatment may be performed during the chlorination reaction or after the chlorination reaction is completed. The depolymerization treatment can be performed by blowing oxygen or adding a radical generator such as a peroxide. The chlorine content can be measured by appropriately extracting the reaction solution during the reaction and measuring according to JIS-K7229.

After completion of the chlorination reaction, the reaction solution is dehydrated, neutralized,
Wash and dry to a powder. The chlorinated rubber powder is easily dissolved in an organic solvent such as toluene, xylene, ethyl acetate, and MEK, and can be used for paints, inks, and adhesives. The viscosity of the organic solvent solution and the properties of the coating film vary depending on the degree of polymerization of the chlorinated rubber.

[0026]

[Effect] Conventionally, adding a metal salt or the like to rubber latex
Although it was known to produce irregular shaped particles of mm, it was not expected that chlorinated rubber would give particles of a uniform size of several tens of μm without additives during the chlorination reaction. . The mechanism is not clearly understood, but is presumed as follows.

If the temperature is raised to several tens of degrees Celsius where the chlorine content is low, the particles themselves in the latex become quite soft and fluid. For this reason, if the interaction between the particles in the latex exceeds the stabilizing effect of the surfactant surrounding the particles, a large coagulated product is easily generated. However, in the case of the present invention, after the chlorine content exceeds 50%, the resin becomes hard, and particularly the outer shell of the particles becomes hard, and even at a temperature higher than the softening start temperature, the surface of the resin particles only partially softens. It is considered that no large coagulated product is formed because the softened portion has low fluidity. In addition, temperature, time,
It is presumed that a certain amount of particles are aggregated and thermally fused under moderate stirring to form uniform large particles.

[0028]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited thereto.

(Example 1) Natural rubber latex (Soctex)
Nonionic surfactant (Emanon 3199, manufactured by Kao) in 3 kg of -CC, high ammonia type, solid content 60%) 54
g in 1 liter of water and 10 liters of water were added and stirred well, and 25 liters of concentrated hydrochloric acid (36%) was added. This was charged into a pressure-resistant reaction vessel having an inner volume of 50 liters and equipped with a stirrer, a high-pressure mercury lamp, a thermometer, and a waste gas discharge port, the inside of which was lined with glass.

After purging the inside of the system with nitrogen gas, chlorine gas was blown at room temperature from a port provided at the bottom of the reaction vessel. Chlorination is continued while gradually increasing the temperature at a rate of 10 ° C./hour. When 4 kg of chlorine is blown in, sampling is performed and the chlorine content is measured. The softening start temperature by DSC is 55%.
80 ° C. The reaction temperature was raised to 85 ° C., the high-pressure mercury lamp was turned on, ultraviolet irradiation was started, and chlorination was continued while gradually increasing the temperature. When the reaction temperature reached 110 ° C., chlorination was continued while maintaining the temperature, and the reaction was terminated when 7 kg of chlorine was blown.

The reaction solution is neutralized, filtered, washed with water, and centrifugally dehydrated.
After 20 minutes, a resin having a water content of 35% was obtained. It was dried with a blow dryer to obtain a chlorinated rubber powder. The chlorine content was 68.0% (% by weight, the same applies hereinafter), and the average particle diameter was 24 μm when the particle diameter was measured by ultrasonic pretreatment (150 W, 1 minute) using a laser diffraction type particle size distribution analyzer. When dissolved in toluene at a solid concentration of 20%, it was easily dissolved and had a viscosity of 41 cp.

Example 2 Natural rubber latex (Soctex)
-CC, high ammonia type, solid content 60%) To 3 kg, add an aqueous solution in which 45 g of a nonionic surfactant (Nonion K-230, manufactured by NOF Corporation) is dissolved in 1 liter of water and 10 liters of water, and stir well. 25 liters of concentrated hydrochloric acid (36%) was added. This was charged into the same reaction vessel as in Example 1.

After purging the inside of the system with nitrogen gas, chlorine gas was blown at room temperature from a port provided at the bottom of the reaction vessel. Chlorination is continued while gradually increasing the temperature. When 5 kg of chlorine is blown, sampling is performed and the chlorine content is measured.
The softening start temperature by DSC was 95%. The reaction temperature was increased to 100 ° C., and chlorination was continued while gradually increasing the temperature. When the reaction temperature reached 120 ° C., chlorination was continued while maintaining the temperature, and the reaction was terminated when 6.5 kg of chlorine was blown.

Post-processing and analysis were performed as in Example 1. The water content of the centrifugally dehydrated resin was 38%, the chlorine content of the dried chlorinated rubber powder was 67.3%, and the average particle size was 30 μm. When dissolved in toluene at a solid concentration of 20%, the viscosity becomes
It was 145 cp.

Example 3 Natural rubber latex (Soctex)
-CC, high ammonia type, solid content 60%) 10 g of cumene hydroperoxide (50% toluene solution) in 3 kg
And 2 g (50% aqueous solution) of tetraethylenepentamine were added and heated to 50 ° C. while stirring. In this state, the reaction was carried out for 3 hours to obtain a depolymerized natural rubber latex.

The depolymerized natural rubber latex is treated with a cationic surfactant (Nymeen T2-210, manufactured by NOF Corporation).
Add 45 g and 15 liters of water, stir well, and add concentrated hydrochloric acid (36
%) 20 liters were added. This was charged into the same reaction vessel as in Example 1, and at room temperature, chlorine gas was blown through a port provided at the bottom of the reaction vessel. Chlorination was continued while gradually increasing the temperature. When 5.5 kg of chlorine was blown in, sampling was performed to measure the chlorine content. The softening start temperature by DSC was 105 ° C. The reaction temperature was increased to 110 ° C., and chlorination was continued while gradually increasing the temperature. When the reaction temperature reached 120 ° C, the temperature was maintained and chlorination was continued.
The reaction was terminated when kg was injected.

Post-processing and analysis were performed as in Example 1. The water content of the centrifugally dehydrated resin was 30%, the chlorine content of the dried chlorinated rubber powder was 65.2%, and the average particle size was 20 μm. When dissolved in toluene at a solid concentration of 20%, the viscosity becomes
13 cp.

(Example 4) Natural rubber latex (Soctex)
An aqueous solution obtained by dissolving 72 g of a nonionic surfactant (Newpole PE-108, manufactured by Sanyo Chemical) in 1 liter of water and 3 kg of 3 kg of -CC, high ammonia type, solid content 60%)
Then, 20 liters of concentrated hydrochloric acid (36%) was added. This was charged into the same reaction vessel as in Example 1.

After purging the inside of the system with nitrogen gas, chlorine gas was blown at room temperature from a port provided at the bottom of the reaction vessel. Chlorination is continued while gradually increasing the temperature. When 5 kg of chlorine is blown, sampling is performed and the chlorine content is measured.
The softening start temperature by DSC was 95%. The reaction temperature was increased to 100 ° C., and chlorination was continued while gradually increasing the temperature. When the reaction temperature reaches 120 ° C, maintain the temperature,
Chlorination was continued while simultaneously blowing chlorine gas and a small amount of oxygen gas, and the reaction was terminated when 6 kg of chlorine was blown.

Post-processing and analysis were performed as in Example 1. The water content of the centrifugally dehydrated resin was 30%, the chlorine content of the dried chlorinated rubber powder was 64.8%, and the average particle size was 25 μm. When dissolved in toluene at a solid concentration of 20%, the viscosity was 6 cp.

Example 5 100 parts of water was placed in a pressure-resistant reaction vessel equipped with a stirrer, a pressure gauge, a thermometer, and an internal injection valve.
3.6 parts of acrylic acid, 2.4 parts of polyoxyethylene alkylphenyl ether sulfate, 0.2 parts of t-dodecylmercaptan, 0.8 parts of potassium persulfate and 0.8 parts of potassium chloride were added, and the mixture was tightly closed and stirred well. Next, 80 parts of isoprene was added into the reaction vessel through an injection valve,
For 12 hours to carry out an emulsion polymerization reaction.

15 kg of water was added to 4 kg of the emulsion-polymerized polyisoprene rubber latex, and the mixture was stirred well.
%) 20 liters were added. This was charged into the same reaction vessel as in Example 1. After purging the inside of the system with nitrogen gas, at room temperature, chlorine gas was blown through a port formed at the bottom of the reaction vessel. Continue to chlorinate while gradually increasing the temperature, 4 kg of chlorine
When chlorine content was measured by sampling at the point where the gas was blown, the softening start temperature by DSC was 60 ° C. The reaction temperature was raised to 70 ° C., and chlorination was continued while gradually increasing the temperature. When the reaction temperature reached 120 ° C., chlorination was continued while maintaining the temperature, and the reaction was terminated when 6 kg of chlorine was blown.

Post-processing and analysis were performed as in Example 1. The water content of the centrifugally dehydrated resin was 35%, the chlorine content of the dried chlorinated rubber powder was 65.0%, and the average particle size was 28 μm. When dissolved in toluene at a solid concentration of 20%, the viscosity becomes
It was 20cp.

Comparative Example 1 Natural rubber latex (Soctex)
Nonionic surfactant (Emanon 3199, manufactured by Kao) in 3 kg of -CC, high ammonia type, solid content 60%) 54
g in 1 liter of water and 10 liters of water were added and stirred well, and 25 liters of concentrated hydrochloric acid (36%) was added. This was charged into the same reaction vessel as in Example 1.

After purging the inside of the system with nitrogen gas, chlorine gas was blown at room temperature from a port provided at the bottom of the reaction vessel. Chlorination is continued while gradually increasing the temperature at a rate of 10 ° C./hour. When 4 kg of chlorine is blown in, sampling is performed and the chlorine content is measured. The softening start temperature by DSC is 55%.
80 ° C. The reaction temperature was set to 75 ° C., a high-pressure mercury lamp was turned on, irradiation with ultraviolet rays was started, and chlorination was continued while gradually increasing the temperature. When the reaction temperature reached 90 ° C., chlorination was continued while maintaining the temperature, but the reaction solution became creamy and the viscosity increased, making it difficult to blow chlorine gas. Slowly inject chlorine gas little by little and take time
The reaction was terminated when kg was injected.

Post-processing and analysis were performed as in Example 1. After 1 hour of centrifugal dehydration, the resin had a water content of 65% and took a long time to dry. The chlorine content of the dried chlorinated rubber powder was 67.0%, and the average particle size was 3 μm. When dissolved in toluene at a solid concentration of 20%, the viscosity was 40 cp.

Comparative Example 2 Natural rubber latex (Soctex)
Nonionic surfactant (Emanon 3199, manufactured by Kao) in 3 kg of -CC, high ammonia type, solid content 60%) 54
g in 1 liter of water and 10 liters of water were added and stirred well, and 25 liters of concentrated hydrochloric acid (36%) was added. This was charged into the same reaction vessel as in Example 1.

After purging the inside of the system with nitrogen gas, chlorine gas was blown in at a temperature of 60 ° C. from a port provided at the bottom of the reaction vessel. Chlorination was continued while gradually increasing the temperature at a rate of 10 ° C./hour. Sampling was performed when 3 kg of chlorine was blown in, but the sampling port was slightly clogged. When the chlorine content was measured, the softening start temperature by DSC was 60 ° C. The reaction temperature was set to 70 ° C., a high-pressure mercury lamp was turned on, irradiation with ultraviolet rays was started, and chlorination was continued while gradually increasing the temperature. When the reaction temperature reached 110 ° C., chlorination was continued while maintaining the temperature, and the reaction was terminated when 7 kg of chlorine was blown.

Post-processing and analysis were performed as in Example 1. When the reaction solution was filtered, there were many lumps of several cm. The water content of the centrifugally dehydrated resin was 35%, and the dried chloride rubber powder was sieved and collected after passing through 200 mesh. The chlorine content was 67.0%, and the average particle size was 50 μm. When dissolved in toluene at a solid concentration of 20%, the viscosity was 45 cp. However, the toluene solution was turbid, and many small lumps that did not dissolve in toluene precipitated.

Performance test of chlorinated rubber The chlorinated rubber of Examples 1 and 3 and Comparative Examples 1 and 2 and the chlorinated rubber of the solution method (Supercron CR-10 (Nippon Paper Industries, Ltd.)
100 parts), 45 parts of salt para (A-40), 125 parts of titanium dioxide, 2.5 parts of stabilizer, and xylene were added and kneaded to prepare a paint. When preparing the paint, the chlorinated rubbers of Examples 1 and 3 were as easy to handle as the chlorinated rubber of the solution method. In the case of the chlorinated rubber of Comparative Example 1, the fine powder was scattered and the periphery was soiled with the powder.
Each paint was applied to a sandblasted steel sheet primed with an inorganic zinc paint and tested for performance. The results are shown in Table 1 below.

[0051]

[Table 1]

In the table, dehydration property: time of centrifugal dehydration (minute) / water content (%) Ease of handling: ease of handling of chlorinated rubber powder Test method Adhesion: Goban eye test, 7 days later Salt spray test: 5% NaCl water is sprayed at 35 ° C.,
After 30 days Moisture resistance: 50 ° C, 100% RH, after 30 days Alkali resistance: Immersion in 3% NaOH water, after 30 days Accelerated weathering: Sunshine weatherometer, 200
After time The results were displayed in five stages of ◎, △, Δ, ×, XX.

[0053]

According to the method of the present invention, the chlorination reaction rate does not decrease even in the latter half of the chlorination reaction, and the properties of the reaction solution do not deteriorate. It is clear from a comparison between Example 1 and Comparative Example 1. In Comparative Example 1, the solution became creamy in the latter half of the reaction and the progress of the reaction was delayed, whereas in Example 1 in which the present invention was carried out, the reaction was It is progressing smoothly.

According to the method of the present invention, the obtained rubber chloride has a large particle diameter, and thus has an effect of improving dehydration and improving handling. When Examples 1 to 5 and Comparative Example 1 are compared, the effect of improving the dewatering property becomes clear. In Examples 1 to 5, the moisture content was low and drying was fast, whereas in Comparative Example 1, the moisture content was very high and both the dehydration property and the drying property were poor. Furthermore, as described in the performance test of the chlorinated rubber, the chlorinated rubber of the present invention is as easy to handle as the chlorinated rubber of the conventional solution method, whereas the chlorinated rubber of Comparative Example 1 is fine powder and can be handled. Inferior.

Claims (6)

(57) [Claims] 1. A process for producing a chlorinated rubber in which a surfactant and an acid are added to a rubber latex and chlorinated with a chlorine gas in a water medium to a chlorine content of 60 to 75%.
And after the softening start temperature becomes 60 ° C or more ,
A process for producing a chlorinated rubber dissolved in an organic solvent, wherein the temperature of the reaction system is raised to a temperature higher than the softening start temperature of the resin at least once to agglomerate and chlorinate the rubber particles. 2. An average particle size of the chlorinated rubber is 10 μm or more.
The method for producing a chlorinated rubber according to claim 1, wherein the thickness is not more than 00 µm. 3. The process for producing a chlorinated rubber according to claim 1, wherein the chlorination is carried out at a temperature of 90 ° C. or more and less than 180 ° C. after the chlorine content exceeds 58%. 4. The method according to claim 1, wherein the rubber latex is a natural rubber or a synthetic polyisoprene rubber. 5. The method for producing a chlorinated rubber according to claim 1, wherein the rubber latex is a depolymerized natural rubber. 6. The process for producing a chlorinated rubber according to claim 1, wherein depolymerization is performed during or after the chlorination reaction.