JPH10265533A - Production of vinyl chloride-based resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a vinyl chloride-based resin capable of providing a molding product more excellent in transparency and impact solution than those of conventional vinyl chloride-based resin. SOLUTION: In this method for producing a vinyl chloride-based monomer obtained by grafting 99-70 wt.% of vinyl chloride alone or a vinyl chloride-based monomer consisting essentially of vinyl chloride onto 1-30 wt.% of an acrylic copolymer latex, the acrylic copolymer latex is obtained by grafting 95-30 wt.% of a mixed monomer composed of (B) 100 pts.wt. of a (meth)acrylate monomer having >=140 deg.C and <30 deg.C glass transition temperature of a homopolymer and (C) 0.1-30 pts.wt. of a polyfunctional monomer onto 5-70 wt.% of a copolymer composed of (A) 100 pts.wt. of a radically polymerizable monomer having 1.51-1.75 birefringence of a homopolymer and (C) 0.1-30 pts.wt. of the polyfunctional monomer. The acrylic copolymer latex has 1.51-1.55 birefringence and 1-200 nm average particle diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a vinyl chloride resin having excellent transparency and impact resistance.

[0002]

2. Description of the Related Art Vinyl chloride resins are originally used in many applications as materials having excellent properties in mechanical strength, weather resistance and chemical resistance. However, when used for hard materials, they have a disadvantage of poor impact resistance, and various improvement methods have been proposed. In particular, for the use of hard vinyl chloride resins which require long-term weather resistance and impact resistance, for example, Japanese Patent Application Laid-Open No. 60-25813 discloses an acrylic copolymer comprising an alkyl (meth) acrylate and a polyfunctional monomer. A vinyl chloride-based resin in which vinyl chloride is graft-copolymerized with the coalescing is disclosed.

However, when the above-mentioned elastic component is mixed into a vinyl chloride resin, the resulting composition generally has an improved impact resistance with an increase in the amount of the elastic component.
On the other hand, transparency, tensile strength, mechanical strength such as flexural modulus tend to decrease, while maintaining impact resistance,
There is an industrial need to improve transparency and mechanical strength.

Japanese Patent Application Laid-Open No. 61-195106 discloses an acrylic copolymer of an alkyl (meth) acrylate, styrene and a polyfunctional monomer as an example for the purpose of improving the transparency and the flexural modulus. A method of graft copolymerizing vinyl chloride has been proposed. However, in this method, although the transparency and mechanical strength of the vinyl chloride resin are somewhat improved, since a homopolymer having a glass transition temperature of about 100 ° C. is used as a copolymer component such as styrene, As the amount of addition increases, the elasticity of the elastic body component is lost, and the impact resistance of the obtained vinyl chloride resin tends to decrease. Therefore, a resin having sufficient balance between transparency, impact resistance and mechanical strength has not been obtained at present.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to obtain a molded article having excellent transparency and impact resistance as compared with conventional vinyl chloride resins. An object of the present invention is to provide a method for producing a base resin.

[0006]

The invention according to claim 1 (hereinafter referred to as the first invention) comprises 1 to 30% by weight of an acrylic copolymer latex containing vinyl chloride alone or vinyl chloride as a main component. In the method for producing a vinyl chloride resin obtained by graft polymerization of 99 to 70% by weight of a vinyl chloride monomer, the acrylic copolymer latex has a homopolymer having a refractive index of 1.51 to 1.75. 100 parts by weight of polymerizable monomer (A) and polyfunctional monomer (C)
5 to 70% by weight of a copolymer comprising 0.1 to 30 parts by weight
To the glass transition temperature of the homopolymer −140 ° C. or higher and 30 ° C.
(Meth) acrylate monomer (B) less than 100
95 to 30% by weight of a mixed monomer comprising 0.1 to 30 parts by weight and a polyfunctional monomer (C) is graft copolymerized, and the refractive index of the acrylic copolymer latex is 1.51 1.55 and the average particle size is 1
２００200 nm.

According to a second aspect of the present invention, there is provided a method for producing a vinyl chloride resin, wherein the acrylic copolymer latex has a glass transition temperature of a homopolymer of −140 ° C. to 30 ° C. Less than 100 parts by weight of a (meth) acrylate monomer (B) and a multifunctional monomer
(C) a copolymer of 30 to 95 consisting of 0.1 to 30 parts by weight
A mixed monomer comprising 100 parts by weight of a radical polymerizable monomer (A) having a refractive index of 1.51 to 1.75 of a homopolymer and 0.1 to 30 parts by weight of a polyfunctional monomer (C) based on the weight%. The acrylic copolymer latex has a refractive index of 1.51 to 1.5% by graft copolymerization of 70 to 5% by weight.
5, and an average particle diameter of 1 to 200 nm.

Hereinafter, the manufacturing method of the first invention will be described. The vinyl chloride resin obtained in the first invention is obtained by graft copolymerization of vinyl chloride alone or vinyl chloride monomer containing vinyl chloride as a main component on an acrylic copolymer latex.

The above-mentioned acrylic copolymer latex comprises a radical polymerizable monomer (A) and a polyfunctional monomer.
A copolymer obtained by graft copolymerizing a copolymer comprising (C) and a mixed monomer comprising (meth) acrylate monomer (B) and polyfunctional monomer (C).

The acrylic copolymer latex is composed of a radical polymerizable monomer (A) having a homopolymer refractive index of 1.51 to 1.75 and a polyfunctional monomer (C). The copolymer has a central layer, and its outer layer is composed of a (meth) acrylate monomer (B) having a glass transition temperature of -140 ° C or more and less than 30 ° C and a polyfunctional monomer (C). A latex having a two-layer structure in which a copolymer having excellent flexibility at room temperature is formed is used.

In the above-mentioned copolymer forming the central layer (hereinafter referred to as the core layer), the homopolymer has a refractive index of 1.51.
The radical polymerizable monomer (A) of ~ 1.75 is used for adjusting the refractive index of the acrylic copolymer latex, and depends on the type of the monomer forming the outer layer (hereinafter referred to as a shell layer). By adding an appropriate amount and adjusting the refractive index of the obtained acrylic copolymer latex to 1.51 to 1.55 which is almost equal to the refractive index of the vinyl chloride resin, the transparency of the vinyl chloride resin is improved. be able to.

In general, when a (meth) acrylate copolymer is added to a vinyl chloride resin, the refractive index of the (meth) acrylate copolymer becomes 1.5, which is the refractive index of the vinyl chloride resin.
Since it is less than 1 to 1.55, the transparency of the vinyl chloride resin is lost due to the incorporation of the (meth) acrylate copolymer, but the acrylic copolymer latex is obtained by conventional pre-mixing of monomers. Unlike copolymerization, the shell layer that absorbs impact by graft copolymerization and the core layer that adjusts the refractive index have an independent two-layer structure, so that transparency is improved without impairing impact resistance. Can be.

Further, by controlling the average particle diameter of the acrylic copolymer latex in the range of 1 to 200 nm, the transparency was further remarkably improved. That is,
The average particle diameter of the latex is set to one half of the wavelength of visible light.
By suppressing the content below, the transparency can be improved.

The above (meth) acrylate monomer (B)
Is generally less than 1.51, the radical polymerizable monomer (A) is selected from monomers having a homopolymer refractive index of 1.51 or more, and has a refractive index of 1 or more. It is difficult to adjust the refractive index of the latex to 1.51 to 1.55 even if it is more than 0.75,
The refractive index of the homopolymer of the radical polymerizable monomer (A) is limited to 1.51 to 1.75.

Examples of the radical polymerizable monomer (A) include 1,3 dichloropropyl methacrylate,
Polar group-containing alkyl (meth) acrylates such as chlorohexyl methacrylate; aromatic alkyl (meth) acrylates such as phenyl methacrylate and benzyl methacrylate; acrylic acid, methacrylic acid, 2-hydroxyethyl (meth) acrylate, 2- Polar group-containing vinyl monomers such as acryloyloxyethylphthalic acid and vinylidene chloride; styrene, α-methylstyrene, o, m, p-
Methylstyrene, o, m, p-propylstyrene, o,
aromatic vinyl monomers such as m, p-chlorostyrene; and unsaturated nitriles such as acrylonitrile and methacrylonitrile. These can be used alone or in combination of two or more.

The radical polymerizable monomer (A)
Is 2 times higher than conventionally used styrene.
Use of a vinyl monomer having a glass transition temperature of 30 ° C. or less of a homopolymer such as -hydroxyethyl acrylate or vinylidene chloride is more preferable in order to enhance the impact resistance of the vinyl chloride resin.

Incidentally, the refractive index of the radically polymerizable monomer (A) can be determined by the method described in Willie Interscience's "Polymer".
Handbook ".

The above (meth) acrylate monomer (B)
Has a glass transition temperature of 30 ° C. for the homopolymer in order to impart flexibility at room temperature to the acrylic copolymer latex.
It is necessary that the temperature be less than 30 ° C., but there is no particular limitation as long as it is less than 30 ° C. However, the temperature is limited to −140 ° C. or more in view of the glass transition temperature of a polymer generally used industrially.

The above (meth) acrylate monomer (B)
Examples thereof include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl (meth) acrylate, isobutyl acrylate, sec-butyl acrylate, cumyl acrylate, n-hexyl (meth) acrylate, and n
-Heptyl (meth) acrylate, n-octyl (meth) acrylate, 2-methylheptyl (meth) acrylate, 2-ethylheptyl (meth) acrylate, 2
-Ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, 2-methyloctyl (meth) acrylate, n-decyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl acrylate, myristyl (meth) acrylate, palmityl methacrylate And alkyl (meth) acrylates such as stearyl methacrylate; 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, and the like. These may be used alone or in combination of two or more. .

In addition, (meth) acrylate monomer
The glass transition temperature of the homopolymer of (B) is published by Baifukan,
Quoted from "Polymer Data Handbook (Basic)" edited by the Society of Polymer Science, Japan.

The polyfunctional monomer (C) not only crosslinks the core layer copolymer and the shell layer copolymer to improve the impact resistance of the vinyl chloride resin, but also provides a copolymer at the time of production and after production. Ideally, coalescing of the coalesced latex particles is prevented, and furthermore, by suppressing the diffusion of the monomer for the shell layer into the core layer copolymer in the second stage of polymerization, phase mixing of the core phase and the shell phase is prevented. For the purpose of forming a typical two-layered latex.

Examples of the polyfunctional monomer (C) include di (meth) acrylate and tri (meth) acrylate. Examples of the di (meth) acrylate include:
Examples include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1.6-hexanediol di (meth) acrylate, and trimethylolpropane di (meth) acrylate. Examples of the acrylate include trimethylolpropane tri (meth) acrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, and pentaerythitol tri (meth) acrylate.

Further, other polyfunctional monomers other than those described above may be used. For example, pentaeristol tetra (meth) acrylate, dipentaeristol hexa (meth) acrylate, diallyl phthalate, diallyl maleate, diallyl fumarate And diallyl compounds such as diallyl succinate and triallyl isocyanurate; and divinyl compounds such as divinylbenzene and butadiene. These may be used alone or in combination of two or more.

In the copolymer for forming the core layer (hereinafter, referred to as the core layer copolymer), the smaller the amount of the polyfunctional monomer (C), the smaller the amount of the particles added during the production and the lower the core layer copolymer. Since the impact resistance of the vinyl chloride resin decreases due to phase mixing of the polymer and the shell layer copolymer, and when the impact resistance increases, it becomes difficult to obtain impact resistance due to an excessively high crosslinking density.
For 100 parts by weight of the radical polymerizable monomer (A),
It is limited to 0.1 to 30 parts by weight, preferably 0.3 to 5 parts by weight.
Parts by weight.

The copolymer for forming the shell layer (hereinafter referred to as “copolymer”)
In the shell layer copolymer), when the addition amount of the polyfunctional monomer (C) is small, coalescence of particles at the time of production and phase mixing of the core layer copolymer and the shell layer copolymer occur, resulting in chloride. The impact resistance of the vinyl-based resin decreases, and if it increases, it becomes difficult to obtain impact resistance due to excessive crosslinking density. Therefore, 0.1 to 30 parts by weight based on 100 parts by weight of the (meth) acrylate monomer (B). And preferably 0.3 to 8 parts by weight.

The weight fraction of the core layer copolymer and the shell layer copolymer forming the acrylic copolymer latex is as follows:
Depending on the combination of the monomers (A) and (B) constituting each, the refractive index of the latex is 1.51 to 1.5.
5, is not particularly limited, but if the weight fraction of the flexible shell layer copolymer is too small, sufficient impact resistance of the vinyl chloride resin cannot be obtained, If it is too large, the transparency of the vinyl chloride resin will not be improved, so that the core layer copolymer is limited to 95 to 30% by weight with respect to the flexible shell layer copolymer of 5 to 70% by weight.

In the present invention, the monomers of the constituents are arranged such that the refractive index of the acrylic copolymer is 1.51 to 1.55, which is substantially equal to the refractive index (1.52 to 1.55) of the vinyl chloride resin. The composition ratio is determined and copolymerized. Refractive index is 1.
If it is less than 51 or greater than 1.55, irregular reflection of light occurs at the interface between the acrylic copolymer and the vinyl chloride resin, and the transparency of the vinyl chloride resin is impaired. The refractive index of the acrylic copolymer is determined by the following formula according to the refractive index of the homopolymer of each monomer forming the core layer and the shell layer and the weight fraction in the latex.

N (P ₁₂ ...) = N (P ₁ ) × W (P ₁ ) + n (
P ₂ ) × W (P ₂ ) +... N (P ₁₂ )) Refractive index of acrylic copolymer 12... N (P ₁ ) Refractive index of homopolymer 1 W (P ₁ ) Acrylic copolymer 12 Weight fraction of homopolymer 1 in n n (P ₂ ) Refractive index of homopolymer 2 W (P ₂ ) Weight fraction of homopolymer 2 in acrylic copolymer 12・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・

The radical polymerizable monomer (A)
The refractive indices of the (meth) acrylate monomer (B) and the polyfunctional monomer (C) were taken from "Polymer Handbook" of Willie Interscience. However,
The refractive index of poly (2-ethylhexyl acrylate) was 1.463, and the refractive index of trimethylolpropane triacrylate was 1.48.

Next, the manufacturing method of the second invention will be described. The vinyl chloride resin obtained in the second invention is obtained by graft copolymerizing an acrylic copolymer latex with vinyl chloride alone or a vinyl chloride monomer containing vinyl chloride as a main component. In addition, the acrylic copolymer latex is obtained by adding a radical polymerizable monomer (A) and a polyfunctional monomer to a copolymer composed of (meth) acrylate monomer (B) and polyfunctional monomer (C). It is obtained by graft copolymerization of a mixed monomer composed of a monomer (C).

The radical polymerizable monomer (A), (meth) acrylate monomer (B) and polyfunctional monomer (C) constituting the acrylic copolymer have the same components as in the first invention. Used.

In the above acrylic copolymer, (meth) acrylate monomer (B) and polyfunctional monomer
The copolymer composed of (C) has a two-layer structure of a core layer, and the copolymer composed of radically polymerizable monomer (A) and polyfunctional monomer (C) has a shell layer.

For the same reason as in the first invention, the acrylic copolymer is limited to a refractive index of 1.51 to 1.55 and an average particle diameter of 1 to 200 nm. In the second invention,
Although the two-layer structure of the core layer and the shell layer is formed of a copolymer opposite to that of the first invention, even if this acrylic copolymer latex is used, the impact resistance of the vinyl chloride resin is impaired. And the transparency can be improved.

In the core layer copolymer, the addition amount of the polyfunctional monomer (C) is 0.1 to 100 parts by weight of the (meth) acrylate monomer (B) for the same reason as in the first invention. It is limited to 1 to 30 parts by weight, preferably 0.3 to 5 parts by weight.

In the above shell layer copolymer, the amount of the polyfunctional monomer (C) added is 0.1 to 100 parts by weight of the radical polymerizable monomer (A) for the same reason as in the first invention. It is limited to 30 parts by weight, preferably 0.3 to 8 parts by weight.

Hereinafter, the production method of the present invention will be described. The method for obtaining the acrylic copolymer latex is not particularly limited, and examples thereof include an emulsion polymerization method and a suspension polymerization method, but from the viewpoint of impact resistance,
In addition, an emulsion polymerization method is preferable because the particle size of the latex can be easily controlled.

When the acrylic copolymer latex is synthesized by the emulsion polymerization method, it is preferable to first synthesize a core layer copolymer and form a shell layer copolymer on the outer layer. At that time, the refractive index of the (hard layer) copolymer comprising the radical polymerizable monomer (A) is 1.51 to 1.75.
The glass transition temperature of the (flexible layer) copolymer comprising the (meth) acrylate monomer (B) is preferably less than 30 ° C.

Further, an emulsifying dispersant and a polymerization initiator are used in the emulsion polymerization method. The emulsifying dispersant is added for the purpose of improving the dispersion stability of the mixed monomer in the emulsion and efficiently performing the polymerization. For example, an anionic surfactant, a nonionic surfactant, and a partially saponified polyether are used. Examples include vinyl acetate, cellulose dispersants, and gelatin. Particularly preferred are, for example, anionic surfactants such as polyoxyethylene nonylphenyl ether sulfate.

Examples of the polymerization initiator include water-soluble polymerization initiators such as potassium persulfate, ammonium persulfate and aqueous hydrogen peroxide, organic peroxides such as benzoyl peroxide and lauroyl peroxide, and azobisisobutyrate. An azo initiator such as lonitrile is exemplified.

In the emulsion polymerization method, a pH adjuster, an antioxidant and the like may be added as necessary.

The emulsion polymerization method includes a batch polymerization method, a monomer dropping method, and an emulsion dropping method depending on the difference in the monomer addition method, but is not particularly limited.
The batch polymerization method is, for example, collectively adding pure water, an emulsifying dispersant, a mixed monomer comprising the acrylic monomer and the polyfunctional monomer into a jacketed polymerization reactor, and removing oxygen and pressurizing by a nitrogen stream. Under these conditions, the emulsion is sufficiently emulsified by stirring, the inside of the vessel is heated to a predetermined temperature by a jacket, and then a polymerization initiator is added to carry out polymerization.

In the monomer dropping method, for example, pure water, an emulsifying dispersant, and a polymerization initiator are charged into a polymerization reactor equipped with a jacket, and the reaction is first carried out under a condition of oxygen removal and pressurization under a nitrogen stream. Is brought to a predetermined temperature by means of a jacket, and then the above-mentioned mixed monomer is added dropwise in a fixed amount to gradually polymerize.

The emulsion dripping method is, for example,
The above-mentioned mixed monomer, emulsifying dispersant, and pure water are sufficiently emulsified by stirring to prepare an emulsifying monomer in advance, and then pure water and a polymerization initiator are put into a jacketed polymerization reactor,
Under the conditions of oxygen removal and pressurization under a nitrogen stream,
First, after the inside of the vessel is heated to a predetermined temperature by a jacket, polymerization is carried out by dropping the above-mentioned emulsified monomer by a predetermined amount. Further, in the emulsion dropping method, if a method of adding a part of the above-mentioned emulsified monomer at a time in the early stage of polymerization (hereinafter referred to as a seed monomer) and then dropping the remaining emulsified monomer is used, by changing the amount of the seed monomer, The particle size of the produced latex can be easily controlled.

To form the core layer copolymer and the shell layer copolymer, any of the above three monomer addition methods may be used. First, the method for forming the core layer copolymer is as follows. The mixed monomer or emulsified monomer is added or dropped at a time, and a polymerization reaction is carried out to synthesize core layer latex particles. Subsequently, the above mixed monomer or emulsified monomer for newly forming a shell layer copolymer is added or dropped at a time, and copolymerization with the core layer particles is performed to form a shell layer on the surface of the core layer particles. It is.

The formation of the shell layer may be performed in the same polymerization process as the formation of the core layer, or the synthesis of the core layer
After recovery, a monomer may be added again to polymerize and form the shell layer. However, in the latter case, it is preferable to newly add the above-mentioned initiator again at the time of polymerization of the shell layer.

The resin solid content of the latex obtained after the polymerization reaction of the acrylic copolymer latex is not particularly limited, but is preferably from 10 to 60 in view of the productivity of the latex and the stability of the polymerization reaction. % By weight is preferred.

In the present invention, the transparency of the vinyl chloride resin is remarkably improved by making the average particle diameter of the acrylic copolymer latex finer than before. That is, it is very important to suppress the average particle diameter of the resin particles to half or less of the wavelength of visible light in order to improve the transparency of the vinyl chloride resin, and it is an essential element of the present invention. ing. Therefore, as the resin particle size of the latex increases, the transparency of the vinyl chloride resin decreases, so that it is limited to 200 nm or less, and is not particularly limited as long as it is 200 nm or less, but the average particle size of the latex that can be generally manufactured industrially In view of this, 1 nm or more is appropriate.
Preferably it is 10 to 100 nm.

The above-mentioned acrylic copolymer latex includes:
For the purpose of improving the mechanical stability of the latex emulsion, a protective colloid agent may be added as needed after the completion of the latex polymerization reaction.

When the proportion of the acrylic copolymer latex in the vinyl chloride resin is small, it is difficult to obtain sufficient impact resistance, and when the proportion is large, the mechanical strength such as bending strength and tensile strength becomes low. , Is limited to 1 to 30% by weight, preferably 4 to
20% by weight.

The method of graft-copolymerizing vinyl chloride alone or vinyl chloride-based monomer containing vinyl chloride as a main component to the acrylic copolymer latex is not particularly limited. For example, a suspension polymerization method, Examples thereof include an emulsion polymerization method, a solution polymerization method, and a bulk polymerization method. In order to carry out the present invention advantageously, a suspension polymerization method is preferable.

The monomer containing vinyl chloride as a main component is
It means a mixture of 50% by weight or more of vinyl chloride and a copolymerizable vinyl monomer, and the copolymerizable monomer is a commonly known vinyl monomer, for example, vinyl acetate, alkyl (meth) acrylate , Alkyl vinyl ether, ethylene, vinyl fluoride, maleimide and the like, and at least one of them can be used.

When graft copolymerizing vinyl chloride,
A coagulant may be added to the acrylic copolymer latex for the purpose of reducing the scale adhering in the polymerization tank during the polymerization.

In the above suspension polymerization method, a dispersant and an oil-soluble polymerization initiator are used. As a dispersant used for suspension polymerization,
The acrylic copolymer latex is added for the purpose of improving the dispersion stability of the latex and efficiently performing graft polymerization of vinyl chloride. For example, poly (meth) acrylate, (meth) acrylate-alkyl acrylate copolymer is added. Polymers, methylcellulose, ethylcellulose, hydroxypropylmethylcellulose, polyethylene glycol, polyvinyl acetate and its partially saponified products, gelatin, polyvinylpyrrolidone, starch, maleic anhydride-styrene copolymer, and the like, alone or in combination of two or more Are used in combination.

Of the above oil-soluble polymerization initiators, radical polymerization initiators are preferably used because they are advantageous for graft copolymerization. Examples thereof include lauroyl peroxide, t-butylperoxypivalate, and diisopropylperoxydioxide. Organic peroxides such as carbonate, dioctyl peroxy dicarbonate, t-butyl peroxy neodecanoate, α-cumyl peroxy neodecanoate, 2,2-azobisisobutyronitrile, 2,2-azobis- Azo compounds such as 2,4-dimethylvaleronitrile and the like can be mentioned.

In the above suspension polymerization method, a pH adjuster, an antioxidant and the like may be added as necessary.

In the method for producing the resin of the present invention, for example, pure water, the above-mentioned acrylic copolymer latex, dispersant, oil-soluble polymerization initiator, water-soluble thickener, Add polymerization degree regulator as needed,
After that, the air in the polymerization vessel was exhausted by a vacuum pump, vinyl chloride and other vinyl monomers were added under stirring conditions, and then the inside of the reaction vessel was heated with a jacket to graft copolymerize vinyl chloride. Is performed.

Since the graft copolymerization of vinyl chloride is an exothermic reaction, the temperature in the reaction vessel, that is, the polymerization temperature can be controlled by changing the jacket temperature.
After completion of the reaction, unreacted vinyl chloride is removed to form a slurry, and the slurry is dehydrated and dried to produce a vinyl chloride resin.

If the degree of polymerization of polyvinyl chloride in the vinyl chloride resin is too small, it becomes difficult to obtain sufficient moldability of the molded article.
2,000, more preferably 400-1600.

The vinyl chloride resin obtained by the production method of the present invention may contain, if necessary, a heat stabilizer, a stabilizing aid, a lubricant, a processing aid, an antioxidant, a light stabilizer and the like at the time of molding. It may be added and used.

Examples of the heat stabilizer include dimethyltin mercapto, dibutyltin mercapto, dioctyltin mercapto, dibutyltin malate, dibutyltin malate polymer, dioctyltin malate, dioctyltin malate polymer, dibutyltin laurate, dibutyltin Organic tin stabilizers such as laurate polymers, lead stabilizers such as lead stearate, dibasic lead phosphite, and tribasic lead sulfate, calcium-zinc stabilizer, barium-zinc stabilizer, barium- Cadmium stabilizers and the like can be mentioned.

Examples of the above stabilizing aid include epoxidized soybean oil, epoxidized linseed oil epoxidized tetrahydrophthalate, epoxidized polybutadiene, phosphate ester and the like.

Examples of the lubricant include montanic acid wax, paraffin wax, polyethylene wax,
Stearic acid, stearyl alcohol, butyl stearate and the like can be mentioned.

Examples of the processing aid include an acrylic processing aid which is an alkyl acrylate / alkyl methacrylate copolymer having a weight-average molecular weight of 100,000 to 2,000,000, and specific examples include n-butyl acrylate / Methyl methacrylate copolymer, 2-ethylhexyl acrylate / methyl methacrylate / butyl methacrylate copolymer and the like can be mentioned.

Examples of the above antioxidant include phenolic antioxidants.

Examples of the light stabilizer include a salicylic acid ester-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ultraviolet absorber, and a hindered amine-based light stabilizer.

Further, a plasticizer may be added to the vinyl chloride resin for the purpose of improving the processability at the time of molding, for example, dibutyl phthalate, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate. And the like.

The above additives may be mixed with the vinyl chloride resin by hot blending or cold blending. Examples of the molding method include extrusion molding, injection molding, and calendering. Molding method, press molding method and the like.

[0068]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples and comparative examples of the present invention will be described below, but the present invention is not limited to these examples.

(Examples 1 to 7, 9, 10 and Comparative Examples 1 to
6, 8, 9) (Preparation of Copolymer Latex Containing Acrylic Polymer) According to the composition table in Tables 1 and 2, a predetermined amount of pure water, an emulsifying dispersant (polyoxy Ethylene nonylphenyl ether ammonium sulfate), a radical polymerizable monomer, and trimethylolpropane triacrylate (hereinafter, referred to as TMPTA) were mixed and stirred to prepare an emulsion monomer. Separately, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), a (meth) acrylate monomer, and TMPTA are mixed and stirred to form an emulsion monomer for forming a shell layer copolymer. did.

On the other hand, pure water was charged into a reaction vessel equipped with a stirrer and a reflux condenser, and oxygen in the vessel was replaced with nitrogen. Then, the temperature of the reaction vessel was raised to 70 ° C. under stirring conditions. Ammonium persulfate (hereinafter referred to as APS) and 50% of the emulsified monomer prepared for forming the core layer copolymer were collectively charged as a seed monomer into the reactor where the temperature was raised, and polymerization was started. Subsequently, the rest of the emulsified monomer prepared for forming the core layer copolymer was dropped. As soon as the dropping of the monomer for the core layer copolymer was completed, the dropping of the monomer for the shell layer copolymer was started. 3 drops all emulsified monomers
After an aging period of 1 hour, polymerization was terminated to obtain an acrylic polymer latex (hereinafter referred to as latex) having a solid content of about 30% by weight.

(Preparation of Vinyl Chloride Resin) Then, pure water, the latex, a 3% aqueous solution of partially saponified polyvinyl acetate, t-
Butyl peroxy neodecanoate and α-cumyl peroxy neodecanoate were charged all at once, then the air in the reactor was discharged with a vacuum pump, and vinyl chloride was further charged under stirring conditions. Was started at a polymerization temperature of 57 ° C. After about 5 hours, the completion of the reaction was confirmed when the pressure in the reactor was reduced to a pressure of 5 kg / cm ² , and the reaction was stopped. Thereafter, the unreacted vinyl chloride monomer was removed, and further dehydration drying was performed to obtain a vinyl chloride resin composition having an average degree of polymerization of vinyl chloride in the vinyl chloride resin of about 1,000.

Example 8 According to the composition table in Table 1, a vinyl chloride resin was synthesized in the same manner as described above. The only difference is that the polymerization was carried out with the amount of the seed monomer being 15% by weight of the emulsified monomer prepared for forming the core layer copolymer.

(Comparative Example 7) According to the composition table in Table 2, a vinyl chloride resin was synthesized in the same manner as described above. The only difference is that the polymerization was carried out with the amount of the seed monomer being 3% by weight of the emulsified monomer prepared for forming the core layer copolymer.

Comparative Example 10 According to the composition table in Table 2, a predetermined amount of pure water, an emulsifier / dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), a radical polymerizable monomer, a (meth) acrylate monomer,
MPTA was mixed and stirred to prepare an emulsion monomer. 35% by weight of the emulsified monomer is used as a seed monomer.
An acrylic copolymer latex and a vinyl chloride resin were synthesized in the same manner as described above.

(Examples 11 to 17, 19 and 20 and Comparative Examples 11 to 16, 18 and 19) (Preparation of copolymer latex containing acrylic polymer) For forming a polymer, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), a (meth) acrylate monomer, and TMPTA were mixed and stirred to prepare an emulsifying monomer. Separately, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), a radical polymerizable monomer, TM
PTA was mixed and stirred to prepare an emulsion monomer.

On the other hand, pure water was charged into a reaction vessel equipped with a stirrer and a reflux condenser, and oxygen in the vessel was replaced with nitrogen. Then, the temperature of the reaction vessel was raised to 70 ° C. under stirring conditions. Into the reactor where the temperature was raised, 50% of the above-mentioned emulsified monomer prepared for the formation of the APS and the core layer copolymer was collectively charged as a seed monomer, and polymerization was started. Subsequently, the rest of the emulsified monomer prepared for forming the core layer copolymer was dropped. As soon as the dropping of the monomer for the core layer copolymer was completed, the dropping of the monomer for the shell layer copolymer was started. After the dropping of all emulsified monomers was completed in 3 hours, and after an aging period of 1 hour, the polymerization was terminated to obtain an acrylic polymer latex (hereinafter referred to as a latex) having a solid content of about 30% by weight. Was.

(Preparation of Vinyl Chloride Resin) Then, pure water, the above latex, a 3% aqueous solution of partially saponified polyvinyl acetate, t-
Butyl peroxy neodecanoate and α-cumyl peroxy neodecanoate were charged all at once, then the air in the reactor was discharged with a vacuum pump, and vinyl chloride was further charged under stirring conditions. Was started at a polymerization temperature of 57 ° C. After about 5 hours, the completion of the reaction was confirmed when the pressure in the reactor was reduced to a pressure of 5 kg / cm ² , and the reaction was stopped. Thereafter, the unreacted vinyl chloride monomer was removed, and further dehydration drying was performed to obtain a vinyl chloride resin composition having an average degree of polymerization of vinyl chloride in the vinyl chloride resin of about 1,000.

Example 18 According to the composition table in Table 3, a vinyl chloride resin was synthesized in the same manner as described above. The only difference is that the polymerization was carried out with the amount of the seed monomer being 15% by weight of the emulsified monomer prepared for forming the core layer copolymer.

(Comparative Example 17) According to the composition table in Table 4, a vinyl chloride resin was synthesized in the same manner as described above. The only difference is that the polymerization was carried out with the amount of the seed monomer being 3% by weight of the emulsified monomer prepared for forming the core layer copolymer.

(Comparative Example 20) According to the composition table in Table 4, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), a (meth) acrylate monomer, a radical polymerizable monomer,
TMPTA was mixed and stirred to prepare an emulsified monomer.
Using 35% by weight of the emulsified monomer as a seed monomer, an acrylic copolymer latex and a vinyl chloride resin were synthesized in the same manner as described above.

The evaluation items and evaluation methods were implemented by the following methods.

[Charpy impact value] JIS K7111
A Charpy impact test was performed in accordance with. The sample was prepared by adding 100 parts by weight of a vinyl chloride resin to 0.1 part of an organotin stabilizer.
Roll kneading of a resin composition obtained by mixing 5 parts and 1.0 part of a montanic acid-based lubricant was performed at 200 ° C. for 3 minutes.
It was prepared from a 3 mm-thick press plate obtained by press molding for 1 minute. The measurement temperature is 23 ° C.

[Tensile strength] A tensile strength test was performed according to JIS K7113. The same sample as the press plate used in the above Charpy impact test was used as the sample. The measurement temperature is 23 ° C.

[Light Transmittance] The light transmittance was measured according to JIS K-6714.

[0085]

[Table 1]

[0086]

[Table 2]

[0087]

[Table 3]

[0088]

[Table 4]

[0089]

The method for producing the vinyl chloride resin of the present invention is as described above.
Transparency, impact resistance and tensile strength are all well-balanced and excellent. By blending ordinary lubricants, stabilizers, etc. used for molding vinyl chloride resin, molding can be performed with good fluidity. Suitable for not only applications such as building materials that require transparency and high impact resistance and tensile strength by utilizing the above properties, and sound barriers with irregular cross sections, but also various plates that require good transparency. Is done.

Claims (2)

[Claims] 1. Acrylic copolymer latex 1 to 30
In a method for producing a vinyl chloride resin obtained by graft polymerization of 99 to 70% by weight of vinyl chloride alone or vinyl chloride-based monomer containing vinyl chloride as a main component, the acrylic copolymer latex is Radical polymerizable monomer (A) 1 having a homopolymer refractive index of 1.51 to 1.75.
The glass transition temperature of the homopolymer is from −140 ° C. to less than 30 ° C. to 5 to 70% by weight of a copolymer composed of 00 parts by weight and 0.1 to 30 parts by weight of the polyfunctional monomer (C) (meth). 95 to 30% by weight of a mixed monomer comprising 100 parts by weight of an acrylate monomer (B) and 0.1 to 30 parts by weight of a polyfunctional monomer (C) is graft copolymerized,
The acrylic copolymer latex has a refractive index of 1.51.
A method for producing a vinyl chloride resin, wherein the average particle diameter is 1 to 200 nm. 2. The acrylic copolymer latex according to claim 2,
A copolymer comprising 100 parts by weight of a (meth) acrylate monomer (B) having a glass transition temperature of 140 ° C. or more and less than 30 ° C. and 0.1 to 30 parts by weight of a polyfunctional monomer (C). Radical polymerizable monomer (A) 1 having a refractive index of a homopolymer of 1.51 to 1.75 at 30 to 95% by weight.
The acrylic copolymer latex has a refractive index of 1.50 parts by weight and 70 to 5% by weight of a mixed monomer comprising 0.1 to 30 parts by weight of a polyfunctional monomer (C). 51 to 1.55, and the average particle diameter is 1
The method for producing a vinyl chloride resin according to claim 1, wherein the thickness is from 200 to 200 nm.