JPH0443084B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a process for producing chlorinated vinyl chloride resins that produces low viscosity, clear solutions.

Vinyl chloride resin is a resin with good chemical resistance. Therefore, vinyl chloride resin is suitable for coating on the surface of objects to prevent corrosion caused by chemicals.
The easiest way to apply it is to dissolve the resin in a solvent to form a solution. However, when vinyl chloride resin is dissolved in an organic solvent, it produces a highly viscous solution, making it unsuitable for coating. Therefore, there was a need for a vinyl chloride resin that would produce a low viscosity solution.

Among vinyl chloride resins, copolymer resins obtained by copolymerizing vinyl chloride with other suitable monomers are known to produce solutions with lower viscosity than homopolymer resins of vinyl chloride. There is. Furthermore, it is known that chlorinated vinyl chloride resin obtained by subsequently chlorinating vinyl chloride resin produces a solution with a lower viscosity than vinyl chloride resin. Therefore, when used as a solution such as paint or adhesive,
Chlorinated vinyl chloride resins were sometimes used.

Chlorinated vinyl chloride resin (hereinafter referred to as CPVC)
Although CPVC has a lower viscosity than polyvinyl chloride resin (hereinafter referred to as PVC), it is still unclear what kind of composition CPVC should have in order to produce a solution with a low viscosity suitable for brush application. Improvements were needed. In addition, the conventional CVPC is
When this was dissolved in an organic solvent to form a solution, the solution became cloudy and could not become transparent. Transparency was required for paints, and transparency was also required in the field of adhesives. Therefore,
There was a desire for a CPVC that would produce a low viscosity, transparent solution.

In order to meet the above request, this inventor
We tried various experiments. As a result, when vinyl chloride is copolymerized with an α-olefin such as ethylene or propylene and the resulting copolymer resin is chlorinated to produce CPVC, this CPVC produces a solution with a low viscosity. It was confirmed. In addition, if only cellulose derivatives are selected and used as a dispersant in the copolymerization process among the CPVC obtained in this way, when the obtained copolymer resin is later chlorinated to produce CPVC, CPVC becomes transparent. It was confirmed that a suitable solution was produced. This invention was completed based on such confirmation.

This invention involves dispersing vinyl chloride and α-olefin in an aqueous medium in which substantially only a cellulose derivative is present as a dispersant, and combining vinyl chloride and α-olefin in the presence of an oil-soluble polymerization initiator. Chlorine to produce a low viscosity, clear solution characterized by polymerization to form a copolymer of vinyl chloride containing 2 to 10% by weight of alpha-olefin and subsequent chlorination of the copolymer. The present invention relates to a method for producing vinyl chloride resin.

In this invention, α-
It consists of a combination of steps: creating a vinyl chloride copolymer containing 2 to 10% by weight of olefin, and chlorinating the resulting copolymer in a subsequent step. By combining these processes,
It is already known to produce CPVC.

This invention is novel in that by using only cellulose derivatives as dispersants during suspension polymerization, CPVC is obtained that produces a clear solution. Cellulose derivatives are known as dispersants. In addition, as a dispersant, those belonging to surfactants and protective colloids can generally be used.
There are many types. That is, in addition to cellulose derivatives, there are many others such as polyvinyl alcohol, polyvinylpyrrolidone, sodium silicate, and sodium phosphate. These dispersants are actually used as a mixture of several types. However, in this invention, a cellulose derivative is selected from among these many dispersants, and this is used alone.
As a result, the resulting PVC was further chlorinated.
It is particularly different in that it is made of CPVC and produces a transparent solution.

In addition, this invention provides α-
CPVC that produces a low viscosity solution by specifically selecting a vinyl chloride copolymer resin containing 2 to 10% by weight of olefin and chlorinating it.
They are particularly different in that they have obtained Therefore, the CPVC obtained in this invention is easy to handle as a solution by dissolving it in a solvent, and is suitable for applying to objects as a paint or adhesive.

The dispersant that can be used in this invention is a cellulose derivative. Cellulose derivatives that can be used include, for example, methylcellulose, ethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose,
Carboxymethyl cellulose, etc. Two or more of these cellulose derivatives can be used in combination if necessary, but they cannot be used in combination with a dispersant other than cellulose derivatives, such as polyvinyl alcohol.

Cellulose derivatives are suitable for monomers to be polymerized.
It is used after being dissolved in water at a ratio of 0.01 part by weight to 0.2 part by weight. The mixing ratio and dissolution operation in this case are the same as those that have been performed up to now.
Something other than a dispersant can be present in the aqueous medium obtained in the presence of a cellulose derivative.

In this invention, the aqueous medium described above is placed in a polymerization vessel. In order to prevent gas such as oxygen from remaining in the polymerization container, the gas inside the polymerization container is removed by reducing the pressure. Thereafter, vinyl chloride and α-olefin are forced into an aqueous medium, and vinyl chloride and α-olefin are dispersed in the aqueous medium.
Copolymerization is carried out in the presence of a polymerization initiator.

Examples of α-olefin include ethylene,
Propylene, butylene, etc. These may be used alone or in combination of two or more.

Either vinyl chloride or α-olefin may be placed in the polymerization container first and then the other. The ratio of vinyl chloride to α-olefin is such that α-olefin is added in excess of the ratio of the desired copolymer.

The proportion of the monomer consisting of vinyl chloride and α-olefin in the aqueous medium is such that the amount of the aqueous medium occupies 100 to 300 parts by weight per 100 parts by weight of the monomer.

In this invention, an oil-soluble polymerization initiator is present in the polymerization vessel. As the oil-soluble polymerization initiator, one already known as a catalyst for suspension polymerization of vinyl chloride or olefin is added according to a known procedure. Oil-soluble polymerization initiators include, for example, benzoyl peroxide,
These are organic peroxides such as lauroyl peroxide and 2-ethylhexyl peroxycarbonate, and azo compounds such as azobisisobutyronitrile. The addition ratio of these polymerization initiators is 0.01 part by weight to 0.1 part by weight based on 100 parts by weight of the monomer to be polymerized.

Things other than those mentioned above, such as antioxidants and PH regulators, may be added to the aqueous medium. Also,
A small amount of an acrylic monomer or other vinyl monomer may be added as a third component as long as it does not adversely affect the intended use. The amount thereof is within the range of 1 to 10% by weight based on the total amount of α-olefin and vinyl chloride.

In order to carry out suspension polymerization in an aqueous medium, the aqueous medium is heated. Heating is preferably carried out at a temperature of 50 to 80°C. The resulting copolymer is separated from the aqueous medium and transferred to a chlorination step.

The chlorination step in this invention is no different from conventional methods. That is, chlorination can be performed in a suspended state, in a solution state, or in a solid state. When it is in a suspended state, the above copolymer is dispersed in water and chlorine is passed through it to chlorinate it. At this time, chlorination may be promoted by irradiation with ultraviolet rays. Also, at this time, a small amount of ketones such as acetone and methyl ethyl ketone may be added to the water.
Furthermore, hydrochloric acid may be added if necessary. Also,
A chlorinated solvent such as trichlorethylene or carbon tetrachloride may be added to an extent that does not significantly impair the particle shape of the copolymer.

The degree of chlorination is preferably such that the chlorine content of the obtained CPVC is 60 to 65% by weight.

The method of this invention is superior to the conventional method in that the obtained CPVC is easily dissolved in an organic solvent, and the resulting solution has a low viscosity and is transparent. Since the solution viscosity is low and it is transparent, it is an excellent component for paints and adhesives, and is industrially useful. Here, the organic solvent refers to a solvent often used in adhesives and paints, and refers not only to a single organic solvent but also to a mixture of a plurality of organic solvents. For example, methyl isobutyl ketone, methyl ethyl ketone,
A single solvent such as acetone, tetrahydrofuran, dimethylformamide, cyclohexanone, methylene chloride, etc., or a mixed solvent such as methyl ethyl ketone/toluene, methyl isobutyl ketone/toluene, ethyl acetate/toluene, etc.

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples and Comparative Examples, and the superior effects of the present invention will be specifically clarified. In Examples and Comparative Examples, parts simply mean parts by weight.

Example 1 (Manufacture of copolymer) In a stainless steel autoclave, 250 parts of ion-exchanged water, 0.25 parts of a cellulose derivative (product name: Metrose 60SH50, manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.13 parts of an oil-soluble polymerization initiator (product name, manufactured by NOF Corporation) were added. After the container was degassed under vacuum, 100 parts of vinyl chloride and 19 parts of ethylene were press-fitted into the container. Thereafter, polymerization was carried out at 60°C for 8 hours to obtain an ethylene-vinyl chloride copolymer.
This copolymer had an ethylene content of 7% by weight and an average degree of polymerization of 690.

(Chlorination process) 400 parts of pure water and 100 parts of ethylene-vinyl chloride copolymer were charged into a glass reactor, and after vacuum degassing, nitrogen was introduced into the container to bring it to normal pressure, and a high-pressure mercury lamp was used. Chlorination was carried out by blowing chlorine at 70°C while irradiating the material. When the chlorine content reached 63% by weight, the chlorination reaction was stopped, the residual chlorine was removed and dried to obtain CPVC.

(Solubility) When the above CPVC was added at a ratio of 15% by weight to a mixed solvent of 4 parts of methyl ethyl ketone and 1 part of toluene, it was easily dissolved. When the viscosity of the solution was measured at 25°C using a B-type viscometer, the viscosity was 1400 cp, which was found to be low. Moreover, this solution was colorless and transparent.

Comparative Example 1 (Production of copolymer) Instead of a cellulose derivative as a dispersant,
0.2 parts of partially saponified polyvinyl alcohol (manufactured by Nippon Gosei Kagaku Co., Ltd., trade name Gohsenol KH-17)
An ethylene-vinyl chloride copolymer having an ethylene content of 7% by weight was obtained in exactly the same manner as in Example 1, except that ethylene was used.

(Chlorination Step) The above copolymer was treated in exactly the same manner as in Example 1 to obtain CPVC with a chlorine content of 63% by weight.

(Solubility) When the viscosity of the above CPVC was measured in exactly the same manner as in Example 1, it was found that the viscosity was 1800 cp, which was low, but the solution was cloudy and the viscosity obtained in Example 1 was It was inferior to what it was.

Comparative Example 2 (Manufacture of copolymer) In a stainless steel autoclave, 200 parts of ion-exchanged water and 0.08 parts of a cellulose derivative (trade name: Metrose 90SH100, manufactured by Shin-Etsu Chemical Co., Ltd.),
0.04 parts of an oil-soluble polymerization initiator (trade name: Perloil L, manufactured by NOF Corporation) was added, the inside of the container was vacuum degassed, and then 100 parts of vinyl chloride was press-fitted. Thereafter, polymerization was carried out at 68°C for 7 hours to obtain a vinyl chloride polymer with an average degree of polymerization of 700.

(Chlorination Step) The above vinyl chloride polymer was chlorinated in exactly the same manner as in Example 1 to obtain CPVC.

(Solubility) When the CPVC thus obtained was dissolved in the mixed solvent of methyl ethyl ketone and toluene of Example 1, the solution became colorless and transparent, but the solution viscosity was high, 87,000 cp.

Example 2 (Production of copolymer) In Example 1, 10 parts of propylene was used instead of ethylene, and the polymerization temperature was changed to 55°C.
A propylene-vinyl chloride copolymer containing 4% by weight of propylene was obtained in exactly the same manner as in Example 1, except for the following. This copolymer had an average degree of polymerization of 450.

(Chlorination Step) The above copolymer was chlorinated in exactly the same manner as in Example 1 to obtain CPVC with a chlorine content of 63% by weight.

(Solubility) When the above CPVC was dissolved in a mixed solvent of methyl ethyl ketone and toluene in exactly the same manner as in Example 1, it was easily dissolved, and the obtained solution was colorless and transparent, and had a low viscosity of 700 cp. It was recognized that there is.

Comparative Example 3 (Production of copolymer) Instead of a cellulose derivative as a dispersant,
The procedure was carried out in exactly the same manner as in Example 2, except that 0.2 parts of polyvinyl alcohol (manufactured by Nippon Gosei Kagaku Co., Ltd., trade name Gohsenol KH-17) was used.
A propylene-vinyl chloride copolymer containing 4% by weight of propylene was obtained. This copolymer has an average degree of polymerization of
It was 450.

(Chlorination Step) The above copolymer was chlorinated in exactly the same manner as in Example 2 to obtain CPVC with a chlorine content of 63% by weight.

(Solubility) When the above CPVC was dissolved in a mixed solvent of methyl ethyl ketone and toluene in exactly the same manner as in Example 2, it was easily dissolved and a solution with a viscosity of 750 cp was produced. It was cloudy and could not be colorless and transparent.

Comparative Example 4 (Manufacture of copolymer) 0.15 parts of cellulose derivative (manufactured by Shin-Etsu Chemical Co., Ltd., trade name Metrose 90SH-100) was used as a dispersant.
A homopolymer of vinyl chloride was obtained in exactly the same manner as in Example 2, except that propylene was not used at all and the polymerization temperature was 85°C. The average degree of polymerization of this polymer is 430
It was hot.

(Chlorination Step) The above polymer was chlorinated in exactly the same manner as in Example 2 to obtain CPVC with a chlorine content of 63% by weight.

(Solubility) When the above CPVC was dissolved in a mixed solvent of methyl ethyl ketone and toluene in exactly the same manner as in Example 2, the solubility was good and the obtained solution was clear and colorless, but the viscosity was high. , the viscosity is
It was 5000 cp.

Example 3 (Manufacture of copolymer) In Example 1, 0.25 parts of a cellulose derivative (manufactured by Shin-Etsu Chemical Co., Ltd., trade name Metrose 90SH100) was used as a dispersant, 16 parts of ethylene was used, and 0.05 parts of a chain transfer agent were used. An ethylene-vinyl chloride copolymer having an ethylene content of 6.5% by weight was obtained in exactly the same manner as in Example 1, except that (mercaptoethanol) was added and the polymerization temperature was 65°C. This copolymer had an average degree of polymerization of 470.

(Chlorination Step) The above copolymer was chlorinated in exactly the same manner as in Example 1 to obtain CPVC with a chlorine content of 63% by weight.

(Solubility) When the above CPVC was dissolved in a mixed solvent of methyl ethyl ketone and toluene in exactly the same manner as in Example 1, it was easily dissolved, and the obtained solution was colorless and transparent, and had a viscosity of 200 cp. It was recognized that the viscosity was low.

Comparative Example 5 (Production of copolymer) In Example 3, no chain transfer agent was used, the amount of cellulose derivative was 0.2 parts, the amount of ethylene injected was 3 parts, and the polymerization temperature was 82°C.
An ethylene-vinyl chloride copolymer having an ethylene content of 1% by weight was obtained in exactly the same manner as in Example 3, except for the following. This copolymer had an average degree of polymerization of 440.

(Chlorination Step) The above copolymer was chlorinated in exactly the same manner as in Example 3 to obtain CPVC with a chlorine content of 63% by weight.

(Solubility) When the above CPVC was dissolved in a mixed solvent of methyl ethyl ketone and toluene in exactly the same manner as in Example 3, it was easily dissolved and the resulting solution was colorless and transparent, but the viscosity was high and the CPVC was 4000 cp. It was hot.

Comparative Example 6 (Production of copolymer) As a dispersant, instead of cellulose derivative
The same procedure as in Comparative Example 5 was carried out, except that 0.16 parts of polyvinyl alcohol (manufactured by Nippon Gosei Kagaku Co., Ltd., trade name Gohsenol KH-17) was used.
An ethylene-vinyl chloride copolymer having an ethylene content of 1% by weight was obtained. This copolymer has an average degree of polymerization of
It was 440.

(Chlorination Step) The above copolymer was chlorinated in exactly the same manner as in Example 3 to obtain CPVC with a chlorine content of 63% by weight.

(Solubility) When the above CPVC was dissolved in a mixed solvent of methyl ethyl ketone and toluene in exactly the same manner as in Example 3, it was easily dissolved, but the resulting solution was
It is cloudy, not colorless and transparent, and has a high viscosity.
It was 4000 cp.

Example 4 (Manufacture of copolymer) In Example 1, 0.23 parts of a cellulose derivative (manufactured by Shin-Etsu Chemical Co., Ltd., trade name Metrose 60SH50) was used as a dispersant, 10 parts of ethylene was used,
An ethylene-vinyl chloride copolymer was obtained in exactly the same manner as in Example 1, except that the polymerization temperature was 62°C. This copolymer contained 4% by weight of ethylene and had an average degree of polymerization of 700.

(Chlorination Step) The above copolymer was chlorinated in exactly the same manner as in Example 1 to obtain CPVC with a chlorine content of 65% by weight.

(Solubility) In exactly the same manner as in Example 1, the above CPVC was added to a 4:1 mixed solution of methyl ethyl ketone and toluene.
When dissolved, it was easily dissolved. The obtained solution was colorless and transparent, and had a viscosity of 950 cp, which was considered to be low viscosity.

Example 5 (Manufacture of copolymer) In Example 1, 0.2 parts of a cellulose derivative (manufactured by Shin-Etsu Chemical Co., Ltd., trade name Metrose 60SH100) was used as a dispersant, and 5 parts as an α-olefin.
An ethylene-vinyl chloride copolymer was obtained in exactly the same manner as in Example 1, except that 50% of ethylene was used and the polymerization temperature was 64°C. This copolymer had an ethylene content of 2% by weight and an average degree of polymerization of 590.

(Chlorination Step) The above copolymer was chlorinated in exactly the same manner as in Example 1 to obtain CPVC with a chlorine content of 64% by weight.

(Solubility) In exactly the same manner as in Example 1, the above CPVC was added to a 4:1 mixed solvent of methyl ethyl ketone and toluene.
When dissolved, it was easily dissolved. The obtained solution was colorless and transparent, and had a viscosity of 750 cp, which was considered to be low viscosity.

Claims (1)

[Claims] 1 Dispersing vinyl chloride and α-olefin in an aqueous medium containing substantially only a cellulose derivative as a dispersant, and copolymerizing vinyl chloride and α-olefin in the presence of an oil-soluble polymerization initiator. , chlorinated vinyl chloride to produce a low-viscosity, transparent solution, characterized by making a copolymer of vinyl chloride containing 2 to 10% by weight of α-olefin, and then chlorinating the copolymer. Method of manufacturing resin.