JPS6136861B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a powdered chlorosulfonated ethylene polymer. Chlorosulfonated ethylene polymers are generally said to have the best properties when manufactured by a solution method, in which ethylene polymer is dissolved in an organic solvent, such as a halogen-containing organic solvent, and chlorine and sulfur dioxide gas are dissolved. , or 10-60 using chlorine and sufuryl chloride
% chlorine and 0.5-4.0% sulfur.

The present invention uses the chlorosulfonated ethylene polymer-containing reaction product liquid obtained by this reaction, that is, the chlorosulfonated ethylene polymer dissolved in a halogen-containing organic solvent, as a raw material, and uses this as a cationic solution. Aqueous emulsification is performed using a surfactant, and then the solvent is removed from this emulsion, and then this is mixed dropwise into an aqueous solution containing a water-soluble anionic polymer compound to obtain a chlorosulfonated ethylene polymer as a powder. In this method, a powdered chlorosulfonated ethylene polymer is produced by separating, dehydrating, and drying the chlorosulfonated ethylene polymer.

Conventionally, chlorosulfonated ethylene polymers have been produced by reacting in a solution as described above, contacting it with steam to remove the solvent, and then drying it, or removing the solvent and drying it on a heated drum. It is then made into chips or bales and supplied for various purposes.

Although chlorosulfonated ethylene polymer has excellent performance as a rubber, its disadvantage is that its properties tend to change depending on thermal history. Coalescence often results in blocks during transportation and storage, or the tackiness and fluidity change significantly due to heating operations during processing. In order to prevent this, it is desirable to use a powder form.

Furthermore, in applications such as paints and adhesives, the chips of the polymer are further shredded to speed up the dissolution rate.

Furthermore, attempts have been made to improve these properties by mixing synthetic resins or other synthetic rubbers with chlorosulfonated ethylene polymers. In such cases, the fact that the chlorosulfonated ethylene polymer is in the form of chips or veils is considered to be a difficult point in processing operations.

Therefore, if the chlorosulfonated ethylene polymer were to be powdered, these manufacturing and processing difficulties would be largely solved.

In general, methods for turning rubber into powder include mechanical methods in which the rubber is cooled to below its embrittlement temperature with liquid nitrogen and crushed, and rubber latex is mixed in the presence of a powder dispersant such as aluminum chloride or water glass. A method of separating rubber or separating rubber by adding a water-soluble polymer compound and a water-soluble inorganic compound to rubber latex (Japanese Patent Application Laid-Open No. 78785/1985) and a method of mixing rubber latex with an anionic polymer. A method of separating rubber particles by adding them to an aqueous solution of cationic polymers, etc., and then adding a synthetic resin emulsion to this (Japanese Patent Application Laid-open No. 73244/1983).
Chemical methods such as

However, these methods have problems such as heat removal, the need for large amounts of anti-blocking agents and powder separation agents, and the quality of the obtained powdered rubber is poor.

In particular, in the case of the chlorosulfonated ethylene polymer that is intended to be powdered in the present invention, there are many difficulties in powdering it by mechanical methods due to its characteristics. Therefore, powdering by chemical methods is considered effective, but there are many problems in powdering chlorosulfonated ethylene polymers obtained by solution methods. In the above-mentioned JP-A No. 53-73244, anionic polymers, cationic polymers, etc. are added in amounts of 0.1 to 100 parts of rubber.
Basically the same amount is used in each 10 parts, but in this method, the chlorosulfonated ethylene polymer obtained from the halogen-containing organic solvent solution of the chlorosulfonated ethylene polymer obtained by the solution method as in the present invention is used. Difficult to powder. If such a method were to be applied, a significantly large amount of anionic polymer and then cationic polymer would have to be used. These substances remain in the polymer and cause coloring, and also accelerate gelation, which has an adverse effect.

The present invention is the result of intensive research aimed at solving the above-mentioned difficulties of the conventional method.

That is, in the present invention, a halogen-containing organic solvent solution containing 100 parts by weight of a chlorosulfonated ethylene polymer obtained by a chlorosulfonation reaction of an ethylene polymer by a solution method is mixed with 11 to 30 parts by weight of a cationic interface. Aqueous emulsification is performed using an activator, and then the organic solvent is removed, and then this is mixed dropwise into an aqueous solution containing 0.5 to 10 parts by weight of a water-soluble anionic polymer compound to form a powder of chlorosulfonated ethylene polymer. This is a method for producing a powdery chlorosulfonated ethylene polymer, which is characterized by separating it into chlorosulfonated ethylene polymers, dehydrating it, and drying it.

According to the present invention, by directly emulsifying a reaction product solution containing a chlorosulfonated ethylene polymer with a cationic surfactant in the amount used above,
Since powdering can be achieved using a relatively small amount of anionic compound, it is possible to control the effects of emulsifiers and additives on the physical properties of the polymer.

Furthermore, with the chemical powdering method described above, it is generally difficult to reduce the particle size to 0.5 m/m or less, and even if powdered, it becomes blocks during the dehydration process such as centrifugation, so this should be prevented. Therefore, it is necessary to add a synthetic resin emulsion, but according to the present invention, the particle size of the powdered chlorosulfonated ethylene polymer is 0.5 m/m or less, and there is no need to add a synthetic resin emulsion.

The present invention will be explained in more detail below.

As a raw material for the chlorosulfonated ethylene polymer to be powdered in the present invention, as described above, a reaction product solution containing a chlorosulfonated ethylene polymer obtained by chlorosulfonation of an ethylene polymer by a solution method is used. A method for obtaining this reaction product liquid containing a chlorosulfonated ethylene polymer is already known, and an outline thereof will be described below. As the ethylene polymer, linear polyethylene or branched polyethylene having a melt index of 0.1 to 200, or a copolymer of ethylene and an ethylenic comonomer copolymerizable therewith can be used.

Comonomers include vinyl acetate, butene-1,
Propylene, acrylic acid, etc. are preferred. These can contain up to 50% by weight, based on the total monomers. Next, the solvent for dissolving these ethylene polymers and chlorosulfonation is a halogen-containing organic solvent, that is, a hydrocarbon compound having 1 to 12 carbon atoms in which part or all of the hydrogen has been replaced with a halogen element. For example, carbon tetrachloride, tetrachloroethane, chloroform, chlorobenzene, hexachlorobutane, etc. can be used.

These solvents are used in an amount of 200 to 2000 parts by weight per 100 parts by weight of the ethylene polymer. The dissolution of the polymer is carried out in an autoclave at a temperature of 50-150°C.

In the chlorosulfonation reaction, chlorine and sulfur dioxide gas or chlorine and sulfuryl chloride are used to react to contain 10 to 60% chlorine and 0.5 to 4.0% sulfur, but chlorine and sulfuryl chloride are used relatively often. To describe the reaction, first, 5-
100 parts by weight of chlorine and 5 to 100 parts by weight of sururyl chloride are added to the polymer solution. The temperature of chlorination is
Although it can be carried out at the same temperature as the solubility of the polymer, when adding sulfuryl chloride, the temperature is preferably 50 to 80°C. Thus, for example, until the chlorine content of the polymer is around 20% by weight, chlorine is added at a temperature of 80-120°C and then sulfuryl chloride is added at a temperature of 50-80°C.

While adding chlorine and sulfuryl chloride, an azo catalyst such as azobisisobutyronitrile was used as a catalyst per 100 parts by weight of the polymer.
It is dissolved in the halogen-containing organic solvent and added continuously in a proportion of 0.1 to 2 parts by weight.

When chlorosulfonation reaches a predetermined value, stop adding the catalyst and boil the solution while blowing an inert gas, such as nitrogen or argon, into the reaction system to eliminate unreacted chlorine gas and by-products. Removes hydrochloric acid.

In the manner described above, a reaction product liquid containing a chlorosulfonated ethylene polymer as a raw material is obtained. This reaction product liquid is then mixed with a cationic surfactant for emulsification.

As the cationic surfactant, higher amines such as polyoxyethylene tallow propylene diamine, tallow alkylamine, hardened tallow alkyldimethylamine, alkyl trilylmethyl ammonium chloride, higher alkyl amines, or acid salts thereof are used.

These surfactants are used in an amount of 11 to 30 parts by weight, preferably 15 to 25 parts by weight, per 100 parts by weight of the chlorosulfonated ethylene polymer. If the amount of surfactant is less than the above range, emulsification will be insufficient and the emulsion will become creamy, resulting in poor stability of the emulsion. If too much is used, it may be difficult to recover the solvent from the emulsion, or the resulting powdered rubber may become unstable. becomes easier to block. Emulsification is
Add these surface active substances to the polymer solution and mix them, or
This is carried out by preparing an aqueous solution of a surfactant in advance and mixing it with a polymer solution.

For emulsification, use an emulsifying machine such as a homomixer or homosinizer that can rotate at high speed. The solvent can be recovered from the emulsified chlorosulfonated ethylene polymer by a conventional method. For example, this can be carried out by contacting with water vapor under reduced pressure or by using a rotary evaporator.

The aqueous emulsion (latex) of the chlorosulfonated ethylene polymer thus obtained is then dropwise mixed into a solution of a water-soluble anionic polymer compound to be powdered.

As the water-soluble anionic polymer compound, sodium carboxymethyl cellulose, gum arabic, sodium alginate, cellulose acetate phthalate, etc. are used, and these are 0.5 parts by weight per 100 parts by weight of the chlorosulfonated ethylene polymer.
100 to 10 parts by weight, preferably 1 to 8 parts by weight
When used by dissolving in 2000 parts by weight of water, if the water-soluble anionic polymer compound is less than this range, it will be difficult to separate the rubber powder, and if it is too much, the physical properties of the obtained rubber will deteriorate.

This solution and the aqueous latex of the chlorosulfonated ethylene polymer can be mixed at room temperature, and the aqueous latex of the chlorosulfonated ethylene polymer is dropped into a gently stirred aqueous solution of the anionic polymer compound. The chlorosulfonated ethylene polymer immediately begins to separate into powder. After the mixing is completed and the powdered chlorosulfonated ethylene polymer is separated, the upper water layer is removed by decantation, centrifugally dehydrated, and then dried with ventilation at below 50°C until the volatile content is below 1%. dry.

The present invention will be explained below with reference to examples, but the present invention is not limited thereto. Note that unless otherwise specified, parts are by weight, and % is by weight.

Example 1 A reaction product solution containing a chlorosulfonated ethylene polymer was prepared using a raw material solution method as follows.

1000 parts of branched polyethylene obtained in a high-pressure production process with a melt index of 10 are dissolved in 10000 parts of carbon tetrachloride at 120° C. in a glass-lined 20 autoclave equipped with a stirrer. Next, chlorine gas is introduced into the system at a rate of 1.5 per minute. At this time, 2.0 parts of azobisisobutyronitrile as a catalyst is dissolved in 200 parts of carbon tetrachloride and continuously added using a pump. When chlorination reached about 20%, the reaction temperature was lowered to 70°C and sulfuryl chloride
Add 350 parts in 1 hour. In the reaction, when the chlorination reaches a predetermined value (about 4 hours later), the addition of the catalyst and chlorine is stopped, and the unreacted chlorine and by-product hydrogen chloride in the solution are boiled while blowing nitrogen. Remove. As a result, 11,904 parts of a carbon tetrachloride solution containing 1,400 parts of chlorosulfonated ethylene polymer was obtained. The resulting chlorosulfonated ethylene polymer contained 30.4% chlorine and 1.4% sulfur.

To 850 parts of carbon tetrachloride solution containing 100 parts of the chlorosulfonated ethylene polymer thus obtained, 20 parts of polyoxyethylene beef tallow propylene diamine (Nimeen DT-203, manufactured by NOF Corporation) was added. Emulsify 1000 parts of water containing 6 parts of glacial acetic acid using a homomixer at room temperature.

Next, carbon tetrachloride was removed from this under reduced pressure using a rotary evaporator at a temperature of 80°C to obtain an aqueous latex of chlorosulfonated ethylene polymer.

Then, 1,000 parts of the aqueous latex containing 100 parts of the obtained chlorosulfonated ethylene polymer was added dropwise to 2,000 parts of an aqueous solution containing 5 parts of sodium carboxymethyl cellulose at room temperature with stirring to form rubber particles. Separated. The upper water layer was decanted and the engine was heated at 1800 rpm for 10
It was centrifugally dehydrated for a minute and dried in a fluidized bed dryer at a temperature of 50° C. or less to a volatile content of 1% or less. The powdered chlorosulfonated ethylene polymer obtained was 98 parts, of which 95% was a fine powder of 60 mesh or less.

Example 2 In a glass-lined 20 autoclave with a stirrer similar to that in Example 1, ethylene vinyl acetate containing 5% vinyl acetate as a raw material and having a melt index of 7 obtained by a high-pressure manufacturing process was heated. 100 parts of polymer to 16,000 parts of carbon tetrachloride
Melts at a temperature of °C. Then add chlorine gas to 1.2
into the system at a rate of 1 minute. At this time, as a catalyst,
2.0 parts of azobisisobutyronitrile to 400 parts of carbon tetrachloride
Dissolve in 1 part and add continuously using a pump. Then 250 parts of sulfuryl chloride are added over about 1 hour. When chlorination reaches a predetermined value, the addition of the catalyst and chlorine is stopped, and unreacted chlorine and by-product hydrogen chloride in the reaction solution are removed by blowing in nitrogen.
22,000 parts of a carbon tetrachloride solution containing 7.2% of chlorosulfonated ethylene vinyl acetate copolymer containing 30.9% and 1.1% of sulfur was obtained.

Next, 1390 parts of this solution (containing 7.2% polymer) was treated in the same manner as in Example 1 to obtain a cationic aqueous latex, which was then powdered to obtain powdered chlorosulfonated ethylene vinyl acetate. 95 parts of copolymer were obtained. Of this, 92% was fine powder of 60 mesh or less.

Example 3 A finely powdered chlorosulfonated ethylene polymer 92 was prepared in the same manner as in Example 1 except that gum arabic was used instead of sodium carboxymethylcellulose as the anionic polymer compound.
I got the department. 85% of this was powdered rubber of less than 60 mesh.

Example 4 After mixing and dissolving an alkyl trilyl melammonium chloride part in 850 parts of a carbon tetrachloride solution containing 100 parts of the same chlorosulfonated ethylene polymer as used in Example 1 at 50 to 60°C, this was heated to 50°C. The mixture was added dropwise to 1,200 parts of water heated to 1,200 parts while stirring with a homomixer to emulsify.

Next, carbon tetrachloride was removed from the mixture under reduced pressure using a rotary evaporator at a temperature of 80°C to obtain an aqueous latex of chlorosulfonated ethylene polymer.

Next, 1,200 parts of the resulting aqueous latex containing 100 parts of the chlorosulfonated ethylene polymer was treated and powdered in the same manner as in Example 1 to obtain 97 parts of a powdered chlorosulfonated ethylene polymer. 92% of it was fine powder of 60 mesh or less.

Comparative Example 1 In preparing the aqueous latex of chlorosulfonated ethylene polymer in Example 1, the same procedure as in Example 1 was carried out, except that the amount of polyoxyethylene beef tallow propylene diamine was changed to 4.0 parts. However, the latex of this product was cream-like and could not be powdered.

Comparative Example 2 A sample was treated in the same manner as in Example 1, except that the amount of carboxymethyl cellulose sodium added in Example 1 was changed to 0.1 part. The obtained powdered rubber had a poor separation condition and was partially separated into lumps.

Claims (1)

[Claims] 1 A halogen-containing organic solvent solution containing 100 parts by weight of a chlorosulfonated ethylene polymer obtained by a chlorosulfonation reaction of an ethylene polymer by a solution method is mixed with 11 to 30 parts by weight of a cationic surfactant. After aqueous emulsification and then removing the organic solvent, the chlorosulfonated ethylene polymer is separated into powder by dropwise mixing it into an aqueous solution containing 0.5 to 10 parts by weight of a water-soluble anionic polymer compound. , dehydration, and drying.