JP3226235B2 - Method for producing vinyl chloride polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a vinyl chloride polymer having excellent heat resistance and excellent moldability, which is suitable for applications exposed to high temperatures.

[0002]

2. Description of the Related Art Conventionally, polyvinyl chloride resin is physically,
Hard and soft materials are widely used in a wide range of fields because they are excellent in chemical properties, hard to age, and have excellent durability, and are inexpensive.

[0003]

However, it is difficult to use polyvinyl chloride resins at high temperatures because they are relatively poor in heat resistance and heat resistance. Therefore, chlorinated polyvinyl chloride resin with improved heat resistance has been developed.
There is a drawback that the molding processability is inferior to ordinary polyvinyl chloride. Further, a vinyl chloride-N-substituted maleimide-based copolymer has been developed, but has a drawback that its thermal stability is inferior to that of ordinary polyvinyl chloride resin. Furthermore, the above-mentioned drawback of thermal stability has been solved by blending an N-substituted maleimide-containing copolymer with a polyvinyl chloride-based polymer, but because of the blending method, heat resistance, especially the B method of JIS-K-7206 The effect is poor at the Vicat softening point. That is, an object of the present invention is to provide a method for producing a vinyl chloride polymer which is excellent in workability and heat deformation resistance in addition to the properties of a conventional polyvinyl chloride resin.

[0004]

Method for producing a vinyl chloride polymer according to the present invention, in order to solve the above-mentioned object, A) vinyl chloride: and 50 to 95 wt%, B) a) at least one represented by the following formula 3 formula N-substituted maleimide compound: 10 to 90% by weight, b) at least one compound selected from alkyl (meth) acrylate or aromatic vinyl: 10 to 90% by weight and c)
Polymeric peroxide represented by Formula 4: 0.01 to 5
N-substituted maleimide copolymer consisting of 5 to 50 % by weight
% By weight in the presence of a free radical generating catalyst.

Embedded image (Wherein, R ¹ is a substituted or unsubstituted aliphatic, alicyclic, or aromatic hydrocarbon group having 1 to 30 carbon atoms; R ² and R ³ are the same or different from each other; hydrogen, fluorine, chlorine, Or a bromine atom, a cyano group or an alkyl group having 3 or less carbon atoms)

Embedded image (However, n is an integer of 10 to 20)

Hereinafter, the present invention will be described in detail. In the method for producing a vinyl chloride polymer according to the present invention, the vinyl chloride of the component A is 50 to 95% by weight, and the N-substituted maleimide copolymer of the component B is 50 to 5% by weight. If the amount of the N-substituted maleimide copolymer as the component B is less than 5% by weight, the effect on heat resistance is poor, and if it exceeds 50% by weight, the formation of particles during the polymerization is not successful, resulting in a block shape, and the workability is also poor. Become inferior.

The N-substituted maleimide copolymer has a number average molecular weight ( _Mn ) of 500 to 1,000,000, a ratio to the weight average molecular weight ( _Mw ), _Mw / _Mn of 1 to 10, JIS-K-7206. It is preferable that the Vicat softening temperature according to the method A is 110 ° C. or higher and the N-substituted maleimide component is uniformly dispersed in the copolymer. In particular, the Vicat softening temperature is important not only for heat resistance but also for processability and physical properties of the vinyl chloride polymer. The constituent components of the copolymer include 10 to 90% by weight of the N-substituted maleimide compound as the component (a),
b) As for (meth) at least one compound selected from acrylic acid alkyl ester or an aromatic vinyl component 90-10 wt%, c) polymeric par as component
Oxide is composed of 0.01-5% by weight ,
By using b) and c) as essential components, it can be a heat-resistant component balanced with vinyl chloride. Here, if the component (a) is less than 10% by weight, the effect on heat resistance is poor, and if it exceeds 90% by weight, processability is poor, which is not preferable.

The N-substituted maleimide compound as the component a) is represented by the above formula (2). Specific examples thereof include N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, -Isopropylmaleimide, Nn-butylmaleimide, Nt-butylmaleimide, N-hexylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N- (p,
m, o) -hydroxyphenylmaleimide, N- (p,
m, o) -methoxyphenylmaleimide, N- (p,
m, o) -chlorophenylmaleimide, N- (p, m,
o) -Carboxyphenylmaleimide, N- (p, m,
o) -Nitrophenylmaleimide, N-laurylmaleimide, N-bicyclo- (2,2,1) -heptyl-2-
Methylmaleimide, N-9,10-ethano-9,10-dihydroanthracenemaleimide, N-triphenylmethylbenzylmaleimide, and the like.
Cyclohexylmaleimide and N-phenylmaleimide are effective.

Specific examples of the alkyl (meth) acrylate as the component (b) include methyl methacrylate, ethyl acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and stearyl methacrylate. Specific examples of the vinyl group include styrene, α-methylstyrene, vinyltoluene and the like. Both of the above components a) and b) can be used alone or in combination of two or more.

The N-substituted maleimide copolymer includes:
It is preferred that the polymeric peroxide represented by the following formula 5 formula as component c) contains 0.01 to 5 wt%.

Embedded image (However, n is an integer of 10 to 20) By this content, the heat resistance of the vinyl chloride polymer obtained by the present invention can be further improved. However, if it exceeds 5% by weight, it becomes difficult to control the polymerization reaction, which is not preferable.

The N-substituted maleimide copolymer further comprises, as d) component, at least one compound selected from polymerizable monomers other than both a) and b) in the range of 0 to 30% by weight. Can be used with Examples of such a polymerizable monomer include vinyl esters such as vinyl acetate, vinyl caproate, vinyl laurate and vinyl stearate; olefins such as ethylene, propylene and isobutylene; isobutyl vinyl ether, octyl vinyl ether, dodecyl vinyl ether, Alkyl vinyl ethers such as phenyl vinyl ether; halogenated olefins such as vinylidene chloride, vinyl fluoride, propylene chloride, and vinyl bromide; acrylics such as acrylic acid, methacrylic acid, crotonic acid, acrylonitrile, maleic anhydride, and itaconic anhydride Derivatives; and the like. The N-substituted maleimide copolymer may be a block copolymer, a random copolymer, or a combination of random copolymers in addition to the copolymer described above. However, in consideration of heat resistance, the N-substituted maleimide is copolymerized. It is desirable that they are uniformly dispersed in the coalescence.

In the method for producing a vinyl chloride polymer of the present invention, the following other polymerizable monomer and a polymer which can be graft-polymerized with vinyl chloride may be used in an amount of 30% by weight or less, preferably 15% by weight, respectively, if necessary. % Can be used. If the content exceeds 30% by weight, characteristics such as mechanical strength and durability inherent to the polyvinyl chloride resin are lost. In addition, the rubber component of these is 10% by weight.
Exceeds 10% by weight because the heat resistance effect is weakened.
It is preferable to stop below. Examples of the other polymerizable monomers include vinyl esters such as vinyl acetate, vinyl caproate, vinyl laurate, and vinyl stearate; olefins such as ethylene, propylene, and isobutylene; isobutyl vinyl ether, octyl vinyl ether, dodecyl vinyl ether; Alkyl vinyl ethers such as phenyl vinyl ether; halogenated olefins such as vinylidene chloride, vinyl fluoride, propylene chloride and vinyl bromide; ethyl acrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate Acrylic acid and methacrylic acid ester such as styrene and stearyl methacrylate; acrylic acid, methacrylic acid, crotonic acid, acrylonitrile, maleic anhydride, itako Acrylic derivatives such as acid, and the like are exemplified, and these may be used alone or in combination of two or more. Examples of the polymer that can be graft-polymerized with vinyl chloride include ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, chlorinated polyethylene, polyurethane, polybutadiene-styrene-methyl methacrylate, polybutadiene-acrylonitrile-α-methylstyrene. , Polybutyl acrylate, butyl rubber, polystyrene, styrene
Butadiene copolymer, cross-linked acrylic rubber and the like are exemplified,
Similarly, they may be used alone or in combination of two or more.

The polymerization of the vinyl chloride polymer according to the method of the present invention is carried out by blending the above-mentioned components at the above-mentioned ratios and performing any of a bulk polymerization method, a suspension polymerization method and an emulsion polymerization method. Generally, the suspension polymerization method is industrially and economically advantageous. The polymerization temperature is selected generally between 0 DEG and 100 DEG C., and the polymerization time is about 1-50 hours. As a method for preparing the N-substituted maleimide copolymer as the component B, a method in which the N-substituted maleimide copolymer is dissolved in a solvent, a method in which the N-substituted maleimide copolymer is dissolved in vinyl chloride, a method in which the copolymer is emulsified, and the like can be considered. Similarly, the method using a solvent adversely affects the reaction system, so the latter two methods are suitable. In this method of dissolving and adding in vinyl chloride, the entire amount is charged into a polymerization vessel before the start of polymerization. At this time, when the amount ratio of the N-substituted maleimide copolymer to vinyl chloride is large, it is not completely dissolved in vinyl chloride, so that the heat resistance effect is slightly weakened, but it is not a problem.

The free-radical generating catalyst used in the process of the present invention may be any of those commonly used in the polymerization of vinyl chloride, such as decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, diisopropyl Peroxydicarbonate, di-2
Diacyl peroxide compounds such as -ethylhexylperoxydicarbonate and acetylcyclohexylsulfonyl peroxide; organic peroxides of peroxyesters such as t-butylperoxypivalate and t-butylperoxyneodecanate; α, α Azo compounds such as' -azobisisobutyronitrile, α, α'-azobis-2,4-dimethylvaleronitrile and α, α'-azobis-4-methoxy-2,4-dimethylvaleronitrile; There are water-soluble peroxides such as potassium sulfate and ammonium persulfate, and these can be used alone or in combination of two or more. As the polymerization method, the suspension polymerization method is preferable as described above, and the suspension stabilizer and the like used in that case may be those usually used for polymerization of a vinyl chloride monomer, such as complete or partial saponification. Synthetic polymer compounds such as polyvinyl alcohol, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose, polyvinylpyrrolidone, maleic anhydride-vinyl acetate copolymer; and natural polymer substances such as starch and gelatin. Are used alone or in combination of two or more.

[0014] The vinyl chloride polymer obtained by the method of the present invention has substantially the same processability as a general polyvinyl chloride resin, and is characterized by giving a molded article having excellent heat resistance and mechanical strength. Have. In obtaining such a molded product, a molding composition may be prepared by blending the following stabilizers, lubricants, antistatic agents, impact modifiers, coloring agents, and the like, if necessary. Examples of the stabilizer include metal salts and soaps such as calcium, cadmium, barium or zinc laurate or stearate; tribasic sulfate, dibasic lead phosphite, dibasic lead phthalate, lead white, lead. Lead stabilizers such as laurate or stearate of di-n-alkyltin mercaptide, di-n-alkyltin dilaurate, dibutyltin dimaleate, dibutyltin lauryl mercaptide, di-octyltin-S, S'-
Bis- (isooctyl-mercaptoacetate), dibutyltin bis-isooctylthioglycolate, di- (n
-Octyl) tin maleate polymers, tin stabilizers such as dibutyltin mercaptopropionate; antimony stabilizers such as antimony mercaptocarboxylate or ester salts; and phosphates.
Among these, powdery ones are desirable because the present invention aims to improve heat resistance. Examples of the lubricant include metal soap, stearic acid, glyceryl monostearate, ethyl diaminostearate, paraffin, and low molecular weight wax.

As the antistatic agent, various cationic, anionic, nonionic or amphoteric surfactants are used. As impact modifiers, chlorinated polyethylene,
Acrylonitrile-styrene-butadiene copolymer, methyl methacrylate-styrene-butadiene copolymer, methyl methacrylate-ethyl-2-ethylhexyl-
Examples thereof include a styrene copolymer and an ethylene-vinyl acetate copolymer. Examples of the coloring agent include carbon black, calcium carbonate, titanium oxide, talc, asbestos, aluminum hydroxide, magnesium hydroxide, color carbon black, chrome yellow, titanium oxide, phthalocyanine green and the like. In addition, acrylonitrile-α-methylstyrene-butadiene copolymer, PMMA
And a heat-resistance improver such as an acrylate copolymer, or a processing aid, a filler, an antioxidant, a flame retardant, a smoke suppressant, and the like which are further compounded in a general vinyl chloride resin. It can be added within a range that does not impair the purpose. As described above, the vinyl chloride-based polymer according to the present invention can be blended, kneaded and molded in the same manner as in the case of a conventional polyvinyl chloride resin in molding processing, and can be produced as a product in any form of pellets or powders. May be supplied. In addition, the molding conditions are the same as those of the conventional vinyl chloride resin, and the above-mentioned excellent molded product can be easily obtained.

[0016]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Examples 1 and 2, Reference Examples 1 to 5 and Comparative Examples 1 to 8 N-substituted maleimide copolymers (component B) shown in Table 1 were put together with vinyl chloride (component A) in a 50 L stainless steel polymerization vessel. 15 kg were charged at the weight ratios shown in Tables 2 and 3, 30 kg of charged water, 20 g of partially saponified polyvinyl alcohol and 7 g of 2-ethylhexyl peroxydicarbonate were charged, and polymerization was carried out at a polymerization temperature of 60 ° C. for 10 hours. Observation and evaluation of the granular state of the obtained vinyl chloride polymer by the following method, measurement of the Vicat softening temperature,
The moldability and the appearance of the molded article were evaluated, and the results are shown in Tables 2 and 3.

Observation / evaluation of the granular form: A ‥‥‥ Good. B ‥‥‥ There is a little block. C ‥‥‥ Block state.・ Measurement of Vicat softening temperature: 100 parts by weight of the obtained vinyl chloride polymer, 5 parts by weight of a lead stabilizer and carbon black
0.003 parts by weight were added and mixed, and a pellet compound was produced with a 50 mmφ extruder. This was press-molded at 190 ° C. for 10 minutes to form a plate, and the Vicat softening temperatures of both A and B methods were measured according to JIS K-7206.・ Evaluation of molding processability and appearance of molded product: The above-mentioned pellet compound is formed into a 1/8 inch round bar by an extruder.
The appearance of the product was observed and evaluated according to the following criteria. ◎ ‥‥‥ The surface is smooth and uniform without flow mark gloss unevenness. ○ ‥‥‥ The surface is smooth and almost no flow mark gloss unevenness is observed. Δ ‥‥‥ Flow mark gloss unevenness is observed on the surface. × ‥‥‥ The surface is not smooth and there is large unevenness of flow mark gloss.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

The vinyl chloride polymer obtained by the production method of the present invention has excellent physical and chemical properties and durability as well as the conventional polyvinyl chloride resin, and also has good workability. Since it has excellent heat deformation resistance, it can be used for applications exposed to high temperatures.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tatsuya Fujimoto 1-figure Towada, Kamisu-cho, Kashima-gun, Ibaraki Shin-Etsu Chemical Co., Ltd. PVC Research Institute (56) References JP-A-2-49013 (JP, A JP-A-1-108209 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 267/10 C08F 257/00 C08F 265/06

Claims (1)

(57) [Claims] 1. A) vinyl chloride: 50 to 95% by weight; B) a) at least one N-substituted maleimide compound represented by the following formula: 10 to 90% by weight; b) (meth) At least one compound selected from alkyl acrylates or aromatic vinyls: 10 to 90% by weight and c)
Polymeric peroxide represented by Formula 2: 0.01 to 5
N-substituted maleimide copolymer consisting of 5 to 50 % by weight
% By weight in the presence of a free radical generating catalyst. Embedded image (Wherein, R ¹ is a substituted or unsubstituted aliphatic, alicyclic, or aromatic hydrocarbon group having 1 to 30 carbon atoms; R ² and R ³ are the same or different from each other; hydrogen, fluorine, chlorine, Or a bromine atom, a cyano group or an alkyl group having 3 or less carbon atoms ) (However, n is an integer of 10 to 20)