JPS6065012A - Graft polymerization - Google Patents

Abstract

PURPOSE:To form a copolymer having a uniform degree of grafting and excellent transparency, by graft-copolymerizing a vinyl chloride monomer in two stages with a trunk polymer suspended in an aqueous medium while keeping the pressure of the monomer at a specified value. CONSTITUTION:A vinyl chloride graft copolymer A [a vinyl chloride monomer (mixture) content of 40-70wt%] is formed by polymerizing a vinyl chloride monomer (optionally, together with other copolymerizable monomers) in the presence of 10-200pts.wt., per 100pts.wt. vinyl chloride monomer (mixture), trunk polymer (e.g., polythylene, chloroprene rubber or polyester) under the saturated vapor pressure of the vinyl chloride monomer (polymerization temperature of about 30-80 deg.C) by using a suspension stabilizer and an oil-soluble initiator in an aqueous medium. Next, the polymerization is continued at a pressure below the saturated pressure of the vinyl chloride monomer (a pressure equal to about 30-90% of the saturated vapor pressure) to produce a vinyl chloride graft copolymer B containing 50-95wt% vinyl choride monomer (mixture) component.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel graft polymerization method in which a vinyl chloride monomer or a mixture of a vinyl chloride monomer and a monomer copolymerizable is polymerized in the presence of a backbone polymer.

A vinyl chloride monomer or a mixture of vinyl chloride monomer and a monomer copolymerizable with vinyl chloride monomer (hereinafter abbreviated as vinyl chloride monomer, etc.) is graft-polymerized on the frame-shaped combination. Methods for producing vinyl chloride-based graft copolymers are already well known. Such graft copolymers are usually produced by a so-called suspension polymerization method, in which a frame-shaped polymer is preliminarily dissolved in vinyl chloride monomer, etc., and then suspended in an aqueous medium for polymerization. In recent years, a graft polymerization method has been proposed in which properties such as transparency are improved by polymerizing the trunk polymer in a swollen state without dissolving it. However, as a result of studies conducted by the present inventors, in this production method, when components such as vinyl chloride monomers polymerize and about 70% of vinyl chloride monomer is contained in the copolymer, the polymerization rate decreases dramatically, resulting in industrial production. It was found that it was extremely difficult to react further than that. Additionally, if excessive amounts of monomer and initiator are forcibly added, a large amount of graft copolymers and homopolymer powders of vinyl chloride monomer with different contents of components such as vinyl chloride monomer will be produced as by-products. It has been found that separation of the mixture is extremely difficult industrially.

The purpose of the present invention is to solve these drawbacks by adding vinyl chloride monomer and the like to water, a suspension stabilizer, and the like. 10 to 200 weight F14' per 100 parts by weight of oil-soluble initiator and vinyl chloride monomer.

Components such as vinyl chloride monomer are polymerized at saturated steam pressure in the presence of a frame type coalescence of 40 to 70% of vinyl chloride monomer.
Vinyl chloride kraft copolymer containing Mf'i41 [A]
Then, in the presence of the graft copolymer [A), vinyl chloride monomer, etc., was subjected to suspension polymerization from Hiko while keeping the polymerization pressure below the saturated vapor pressure of the vinyl chloride monomer, to obtain vinyl chloride monomer. The purpose of the present invention is to provide a new graft polymerization method for obtaining a vinyl chloride graft copolymer CB) containing 50 to 95% by weight of components such as polyvinyl chloride.

The present invention will be further explained in detail below.

, as the frame type combination used in the present invention, polyethylene.
Polyolefin polymers such as amorphous polypropylene, chlorinated polyethylene, chlorosulfonated polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene-diene copolymer, and chloroprene rubber. Phyl rubber. Rubbers or rubber-containing copolymers such as styrene-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, imprene rubber, and nitrile rubber.

Examples include condensation polymers such as polyester and polyurethane.

It is preferable that the frame type combination is present in an amount of 10 to 200 parts by weight per 100 parts by weight of the vinyl chloride monomer.

Monomers that can be copolymerized with vinyl chloride monomers include, for example, olefins such as ethylene and propylene, and monocarboxylic acids having carbon atoms ranging from 1 to 18, such as vinyl acetate and vinyl laurate. vinyl alcohols,
Methyl acrylate. Acrylic acid alkyl esters and methacrylic acid alkyl esters in which the alkyl group has a carbon number of 1 to 18, such as butyl acrylate, methyl methacrylate, butyl methacrylate, and octyl methacrylate, as well as phthyl pinylether and lauryl vinyl ether. and vinylidene chloride.

These monomers may be one type or a combination of several types,
Although it can be used freely, the amount to be mixed is preferably 50 parts by weight or less per 100 parts by weight of vinyl chloride.

The suspension stabilizer may be one commonly used in suspension polymerization such as vinyl chloride monomer, such as partially saponified polyvinyl acetate, gelatin, alkylcellulose, polyethylene glycol fatty acid ester, etc. is used. As oil-soluble radical polymerization initiators, azo compounds,
Peroxides can be used, such as azobisisobutyronitrile, dialkyl peroxydicarbonate, lauroyl peroxide, and the like.

The pressure below the saturated vapor pressure is within the range of 30 to 90 inches of the saturated vapor pressure at the reaction temperature of the vinyl chloride monomer.

If it is 90% or more, the effect of polymerization below the saturated steam pressure will not be exhibited, and if it is less than 60%, the reaction rate will be too slow, which is not preferable. An example of a method for keeping the pressure constant is a method in which vinyl chloride monomer or the like is added continuously or intermittently to the polymerization vessel.

The polymerization temperature is 5°C as in the case of ordinary vinyl chloride monomer polymerization.
A range of 0 to 80°C applies.

The amount of components such as vinyl chloride monomer in the graft copolymer CA) is preferably 40 to 70% by weight.

If it is less than 40%, the polymerization rate will be extremely slow if the content of components such as vinyl chloride monomer exceeds 70% during the subsequent polymerization below the saturated vapor pressure. The effects of polymerization, such as good transparency, cannot be obtained.

During the graft polymerization according to the present invention, polymerization regulators such as dodecyl mercaptan may be added if necessary, and processing stabilizers and auxiliaries for vinyl chloride polymers, such as epoxy stabilizers, metal soaps, etc., may be added in advance. can also be added.

As described above, the vinyl chloride graft copolymer CB) obtained by the method of the present invention has good transparency and can be used in a wide range of fields in the future.

The present invention will be explained below with reference to Examples, but the present invention is not limited thereto.

In addition, measurements of properties in the following examples were performed in accordance with the following.

[A) Formulation Table-1 CB) Transparency The formulation shown in Table-1 was rolled at a roll temperature of 1 using a 6-inch roll.
The mixture was kneaded at 60° C. for 5 minutes, pressed at 180° C. for 915 minutes at 9/cr/l to form a 1 m thick sheet, and its light transmittance and haze were measured using a haze meter.

[C] Trunk polymer tyrene-vinyl acetate copolymer (denoted as IDVA in the table)
The product is Toyo Soda Kogyo's Tsurutra Seven 750° Ethylene.
The ethyl acrylate copolymer (denoted as PEA in the table) is
DPDJ9169 manufactured by Nippon Unicar, polymethyl methacrylate (denoted as PMMA in the table), Delpet 6ON manufactured by Asahi Kasei Corporation, polyurethane (denoted as PU in the table),
Nippon Polyurethane (Puri Baraprene 22S, ethylene-propylene-diene copolymer (denoted as EPDM in the table)
EP570 manufactured by Nippon Synthetic Rubber (...) was used. Chlorinated polyethylene (indicated as OPK in the table) was Gisolac G255 manufactured by Osaka Soda.

Examples 1 to 5 Pure water 2 was placed in an SOZ stainless steel polymerization container equipped with a stirring device.
71c9. Frame type combination 4.6 and 9. After charging 36 g of partially saponified polyvinyl acetate, the lid was closed and the reactor was replaced with nitrogen. The reactor was evacuated and 12.6 kg of vinyl chloride monomer was introduced. Heating was started while stirring, and stirring was continued at 60° C. for 93 hours. Subsequently, 8 g of Z2/azobisλ4-dimethylvaleronitrile was added to initiate polymerization.

After 4 hours, the unreacted vinyl chloride monomer was recovered and the pressure was brought to 70 degrees, which is the saturated steam pressure. After that, vinyl chloride monomer was added successively to maintain this pressure, and after polymerization for 6 hours, it was dehydrated. It was dried to obtain a graft copolymer CB). Table 2 shows the measurement results of the properties of the obtained graft copolymer [B].

Examples 6 to 7 After charging 27.1% pure water, 8 kg of the combined frame, and partially saponified polyvinyl acetate 509 into the polymerization container used in Example 1, the lid was closed and the atmosphere was replaced with nitrogen, and then vinyl chloride was dissolved in a vacuum. Add 9 to 10 monomers, start heating while stirring, and heat to 65
C. Stirring was continued for 2 hours. followed by 2.2'Azobis2
．． Polymerization was started by adding 7.7 g of 4-dimethylvaleronitrile. After 5 hours, unreacted vinyl chloride monomer was recovered and the pressure was brought to 60% of the saturated steam pressure. After that, vinyl chloride monomer was added successively to maintain this pressure, and after polymerization for 4 hours, It was dehydrated and dried to obtain a graft copolymer [B]. Table 2 shows the measurement results of the properties of the obtained graft copolymer CB).

Comparative Examples 1 and 2 27 Jt9. 1.1 kg of frame combined, 16 vinyl chloride monomers, 9. After 40 g of partially saponified polyvinyl alcohol was charged and dissolved at 60°C for 3 hours, 6 g of 2,2'azobis2,4-dimethylvaleronitrile was added and reacted for about 8 hours. Thereafter, it was dehydrated and dried to obtain a graft copolymer. Table 2 of the results
It was shown to.

Comparative Example 5 In the polymerization container used in Example 1, 30 kg of pure water was added, 91% partially saponified polyvinyl acetate 50F was added to chlorinated polyethylene 5,
Z2'Azobisz4-dimethylvaleronitrile 109 was charged and vinyl chloride monomer 1. ．． 5 IC9
and heated to 60°C. The pressure at this time was about 65 inches, which is the saturated vapor pressure. After that, vinyl chloride monomer was added successively to maintain this pressure) 1
When vinyl chloride monomer was added after 0 hours, the pressure increased, so the reaction was continued for another 8 hours, but
There was almost no change in pressure.

After dehydration and drying, a graft copolymer was obtained. Table 2 of the results
It was shown to.

Comparative Example 4 50 kt1. of pure water was added to the polymerization vessel used in Example 1. Ethylene-vinyl acetate copolymer 5-gin 1 partially saponified polyvinyl acetate sa9. 4 g of zz'azobis2,4-dimethylvaleronitrile was charged and heated to 60°C while stirring.

The pressure at this time was about 55 inches, which is the saturated vapor pressure. Thereafter, vinyl chloride monomer was successively added so as to maintain this pressure, and the mixture was allowed to react for 6 hours.

Thereafter, 4 g of z2'azobis2,4-dimethylvaleronitrile was further added, and the mixture was reacted for 6 hours while maintaining the same pressure. After dehydration and drying, a pellet-shaped graft copolymer was obtained. The results are shown in Table-2.

The vinyl chloride component in the graft copolymer was 79%, but the fine powder with a vinyl chloride content of 95% or more was approximately 1.0%.
% sub-occurred.

Table 2 Note: The proportion of vinyl chloride component in the niger raft copolymer (A) was measured by partial extraction and extraction.

As described above, in all of the examples, the kraft copolymer CB has excellent transparency with no variation in the content of vinyl chloride component.
)was gotten.

Patent applicant: Toyo Soda Kogyo Co., Ltd.

Claims (1)

[Scope of Claims] 1) Vinyl chloride monomer or a monomer mixture of vinyl chloride monomer and a monomer copolymerizable with vinyl chloride monomer in water, a suspension stabilizer, and an oil-soluble an initiator and the monomer, or
The vinyl chloride monomer is polymerized at saturated vapor pressure in the presence of 10 to 200 parts by weight of a framework polymer per 100 parts by weight of the monomer mixture, and the vinyl chloride component or vinyl chloride and a monomer copolymerizable with vinyl chloride are obtained. A vinyl chloride graft copolymer [A) containing 40 to 70% by weight of polymer components is produced, and then vinyl chloride monomer or vinyl chloride monomer and vinyl chloride are added in the presence of the graft copolymer (A). A mixture of monomers and copolymerizable monomers is subjected to suspension polymerization while maintaining the polymerization pressure below the saturated vapor pressure of the vinyl chloride monomer, and copolymerized with the vinyl chloride component or vinyl chloride and vinyl chloride. A graft polymerization process characterized in that it produces a vinyl chloride graft copolymer CB) containing 50 to 95% by weight of possible monomer components. 2) The frame type is made of polyethylene and amorphous polypropylene. The graft polymerization method according to claim 1, wherein the graft polymer is a polyolefin polymer such as chlorinated ethylene, chlorosulfonated polyethylene, ethylene-vinyl acetate copolymer, or ethylene-propylene diene copolymer. 3) The frame type is made of chloroprene rubber and butyl rubber. Styrene-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, methyl methacrylate
The graft polymerization method according to claim 1, wherein the graft polymerization method is a rubber or a rubber-containing polymer such as a butadiene-styrene copolymer, isoprene rubber, or nitrile rubber. The graft polymerization method according to claim 1, wherein the frame-type polymer is a condensation polymer such as polyester or polyurethane.