JPH10316723A - Vinyl chloride resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vinyl chloride resin which has excellent heat stability during molding and can give moldings having high impact resistance. SOLUTION: This resin is prepared by grafting 99-40 pts.wt. vinyl chloride or a vinyl monomer based thereon onto 1-60 pts.wt. acrylic copolymer comprising 100 pts.wt. mixture comprising 5-50 wt.% epoxy radical-polymerizable vinyl monomer and 95-50 wt.% (meth)acrylate monomer which can give a homopolymer having a secondary transition point of -140 to -20 deg.C and 0.1-30 pts.wt. polyfunctional monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin, and more particularly to a vinyl chloride resin having excellent thermal stability during molding and giving a molded article having high impact resistance.

[0002]

2. Description of the Related Art Vinyl chloride resins have been used in a wide range of applications because of their excellent mechanical strength, weather resistance and chemical resistance. However, they are poor in impact resistance and have restrictions such that they cannot be used for applications requiring these strengths, for example, pipes requiring earthquake resistance. As a method for imparting impact resistance to a vinyl chloride resin, for example, Japanese Patent Application Laid-Open No. 60-25813 discloses a method of graft copolymerizing vinyl chloride with a cross-linked acrylic copolymer to provide excellent impact resistance and weather resistance. A method for producing a vinyl chloride resin is disclosed.

[0003] However, the vinyl chloride resin obtained by the method for producing a vinyl chloride resin disclosed in Japanese Patent Application Laid-Open No. 60-255813 generates a large amount of heat upon kneading at the time of molding. In addition, the initial coloring becomes remarkable, and in particular, there is a problem that molding of a light-colored product becomes difficult.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above facts, and has as its object to provide a molded article having excellent thermal stability during molding and having high impact resistance. To provide a vinyl chloride-based resin.

[0005]

According to the first aspect of the present invention,
Epoxy group-containing radically polymerizable vinyl monomer 5 to 50
% By weight and the secondary transition point of the homopolymer is -140 to -20.
1 to 60 parts by weight of an acrylic copolymer consisting of 100 to 100 parts by weight of a mixed monomer composed of 95 to 50% by weight of a (meth) acrylate monomer and 0.1 to 30 parts by weight of a polyfunctional monomer. The gist of the present invention is a vinyl chloride resin characterized in that 99 to 40 parts by weight of a vinyl monomer mainly composed of vinyl or vinyl chloride is graft-copolymerized.

The epoxy group-containing radically polymerizable vinyl monomer used in the present invention is not particularly limited, but examples thereof include unsaturated hydrocarbon oxides such as 1-vinylcyclohexane-3,4-epoxide and butadiene monoxide. Unsaturated glycidyl ethers such as vinyl glycidyl ether and allyl glycidyl ether; glycidyl esters of unsaturated monocarboxylic acids such as glycidyl acrylate, glycidyl methacrylate, glycidyl crotonate, glycidyl cinnamate, and glycidyl vinyl benzoate; unsaturated dicarboxylic acids Monoalkyl monoglycidyl esters or diglycidyl esters of acids are mentioned. Of these, glycidyl acrylate and glycidyl methacrylate are preferred from the viewpoint of enhancing impact resistance, and glycidyl methacrylate is particularly preferred. These epoxy group-containing radically polymerizable vinyl monomers may be used alone or in combination of two or more.

The homopolymer has a secondary transition point (Tg) of-
The (meth) acrylate-based monomer having a temperature of 140 to −20 ° C. is not particularly limited, but, for example, ethyl acrylate (Tg = −24 ° C., hereinafter, only the temperature is shown in parentheses), n-propyl acrylate (− 37 ° C), n-
Butyl acrylate (-54 ° C), isobutyl acrylate (-24 ° C), sec-butyl acrylate (-2
1 ° C.), n-hexyl acrylate (−57 ° C.), 2-
Ethylhexyl acrylate (-85C), n-octyl acrylate (-85C), n-octyl methacrylate (-25C), isooctyl acrylate (-45C)
C), n-nonyl acrylate (-63C), n-nonyl methacrylate (-35C), isononyl acrylate (-85C), n-decyl acrylate (-70C).
° C), n-decyl methacrylate (-45 ° C), lauryl methacrylate (-65 ° C) and the like. These epoxy group-containing radically polymerizable vinyl monomers may be used alone or in combination of two or more.

If the homopolymer of the (meth) acrylate monomer used in the acrylic copolymer in the present invention has a Tg of less than -140, the tensile strength and the bending strength of the product molded from the obtained vinyl chloride resin are reduced. There is a possibility that sufficient mechanical strength such as elastic modulus may not be obtained, and if it exceeds -20 ° C, sufficient flexibility and impact resistance cannot be obtained.

In the acrylic copolymer of the epoxy group-containing radically polymerizable vinyl monomer, an alkyl (meth) having a secondary transition point of a homopolymer of -140 to -20 ° C.
If the copolymerization ratio with respect to the acrylate monomer is less than 5% by weight, the thermal stability during molding of the obtained vinyl chloride resin is reduced, and if it exceeds 50% by weight, the impact resistance is reduced. % By weight, preferably 10 to 40% by weight.

The above-mentioned polyfunctional monomer is, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane. (Meth) such as tri (meth) acrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate
Examples include acrylates, diallyl phthalate, diallyl maleate, diallyl fumarate, diallyl succinate, allyl compounds such as triallyl isocyanurate, divinyl compounds such as divinylbenzene, and dienes such as butadiene. These polyfunctional monomers may be used alone, or two or more kinds may be used in combination.

The acrylic copolymer is composed of 100 parts by weight of a (meth) acrylate monomer having a Tg of the homopolymer of -140 to -20 ° C. and 0.1 of a polyfunctional monomer.
It is obtained by copolymerization at a monomer weight ratio of ３０30 parts by weight.
When the copolymerization ratio of the polyfunctional monomer is T
If the amount is less than 0.1 part by weight based on 100 parts by weight of the (meth) acrylate-based monomer having a g of -140 to -20 ° C, the impact resistance of a product molded using the obtained vinyl chloride-based graft copolymer is reduced. The property cannot be improved sufficiently. On the other hand, if the amount is more than 30 parts by weight, the molded article becomes hard and brittle, the impact resistance is reduced, and the flexibility is significantly reduced. ) 100 parts by weight of acrylate monomer
It is limited to 1 to 30 parts by weight, preferably 0.1 to 15 parts by weight.

The vinyl monomer other than vinyl chloride, which is graft-copolymerized with the above-mentioned acrylic copolymer together with vinyl chloride, is appropriately selected and used depending on the use of the obtained vinyl chloride resin. Although it is not particularly limited as long as it can be copolymerized with vinyl chloride, for example, ethylene, propylene, α-olefins such as butylene, vinyl acetate, vinyl esters such as vinyl propionate, ethyl vinyl ether, Vinyl ethers such as butyl vinyl ether, (meth) acrylates such as methyl (meth) acrylate, butyl (meth) acrylate, and hydroxyethyl (meth) acrylate; aromatic vinyls such as styrene and α-methylstyrene; Halo such as vinyl, vinylidene fluoride and vinylidene chloride Examples thereof include N-substituted maleimides such as vinyl genide, N-phenylmaleimide, and N-cyclohexylmaleimide. These may be used alone or in combination of two or more.

The amount of the vinyl monomer other than vinyl chloride to be graft-copolymerized with the above-mentioned vinyl chloride is from 99 to 40 in the total amount of the vinyl monomer mainly composed of vinyl chloride.
Of the parts by weight, 20 parts by weight or less is desirable. If the amount of the vinyl monomer other than vinyl chloride exceeds 20 parts by weight, preferable properties inherent in the vinyl chloride resin may be reduced or lost.

The method for obtaining the acrylic copolymer is not particularly limited, and examples thereof include an emulsion polymerization method, a suspension polymerization method, and a dispersion polymerization method. Among them, the emulsion polymerization method is a preferred polymerization method because the particle size of the obtained acrylic copolymer is easily controlled. The emulsion polymerization method is not particularly limited, and a known method such as a batch polymerization method, a monomer addition method, and an emulsion dropping method can be appropriately selected and used. In the above polymerization, an emulsifying dispersant, a polymerization initiator, a pH adjuster, an antioxidant and the like are used as necessary.

Examples of the emulsifying dispersant include anionic surfactants such as polyoxyethylene nonyl phenyl ether sulfate, nonionic surfactants, partially saponified polyvinyl alcohol, cellulose dispersants, and gelatin. Examples of the polymerization initiator include water-soluble polymerization initiators such as ammonium persulfate, potassium persulfate, and hydrogen peroxide; organic peroxide-based polymerization initiators such as benzoyl peroxide and lauroyl peroxide; and azobisisobutyronitrile. And other azo compound-based polymerization initiators.

When the amount of the vinyl monomer mainly composed of vinyl chloride to be graft-copolymerized exceeds 99 parts by weight, that is, the content of the acrylic copolymer in the obtained vinyl chloride resin is 1% by weight. %, The thermal stability at the time of molding may not be sufficiently obtained, and the impact resistance of the molded article may not be sufficiently obtained. If the amount is less than 40 parts by weight, the moldability may be reduced. Therefore, the amount of the vinyl monomer mainly composed of vinyl chloride is 99 to 40.
Parts by weight, preferably 96 to 50 parts by weight.

Next, the above acrylic copolymers 1 to 60
With respect to parts by weight, vinyl chloride or 99 to 40 parts by weight of a vinyl monomer mainly composed of vinyl chloride is graft-copolymerized. When the graft copolymerization amount of the vinyl chloride is more than 99 parts by weight based on 1 to 60 parts by weight of the acrylic copolymer composition, sufficient thermal stability during molding cannot be obtained, and the molded article is formed. There is a possibility that the impact resistance of the molded article may not be sufficiently obtained, and if it is less than 40 parts by weight, the moldability is reduced, and the mechanical strength such as the creep strength of the molded article is decreased. The added amount of vinyl chloride or a vinyl monomer mainly composed of vinyl chloride is 99 to 40 parts by weight, preferably 96 to 50 parts by weight.

The method of graft copolymerizing vinyl chloride or a vinyl monomer mainly composed of vinyl chloride with the acrylic copolymer is not particularly limited. Examples thereof include emulsion polymerization, suspension polymerization, and solution polymerization. A polymerization method and the like can be mentioned. In particular, the suspension polymerization method can be suitably used because the productivity of the vinyl chloride graft copolymer is high.

The above graft copolymerization reaction is preferably carried out by a radical polymerization method. Examples of the radical polymerization initiator used include organic peroxides such as lauroyl peroxide, t-butylperoxypivalate, diisopropylperoxydicarbonate and dioctylperoxydicarbonate; and 2,2-azobisisopropane. Oil-soluble polymerization initiators such as azo compounds such as butyronitrile and 2,2-azobis-2,4-dimethylvaleronitrile are exemplified. These may be used alone or in combination of two or more.

When the above acrylic copolymer is graft-copolymerized with vinyl chloride or a vinyl monomer mainly composed of vinyl chloride by a suspension polymerization method, for example, pure water, an oil-soluble polymerization initiator is placed in a jacketed polymerization reactor. The emulsified water of the acrylic copolymer composition, a suspension stabilizer such as a dispersant, and a polymerization degree adjuster are added if necessary, and the inside of the reactor is sealed to exclude air therein. While stirring the inside, a vinyl chloride monomer and other vinyl monomers as needed are added, and the inside of the reactor is heated to a predetermined temperature to start graft copolymerization. The reaction is terminated while adjusting the inside of the reactor to a predetermined temperature by the heat medium in the jacket. After the completion of the reaction, unreacted vinyl chloride monomer and other vinyl monomers are removed to obtain a slurry-like vinyl chloride resin. This is dehydrated and dried to obtain a vinyl chloride resin product.

The degree of polymerization of the obtained vinyl chloride resin is not particularly limited. However, if the degree of polymerization is too small, the impact resistance of the obtained molded article decreases, and if it is too large, the moldability decreases. And the resulting molded article becomes hard and brittle,
For each application used, the viscosity average degree of polymerization determined in accordance with JIS K 6721 is preferably 300 to 250.
0, more preferably in the range of 400 to 2000.

The vinyl chloride resin is used alone as a molding material, but can also be used as a modifier for the vinyl chloride resin. When the vinyl chloride resin is used as a molding material, a stabilizer, a stabilizing aid, an antioxidant,
Various processing aids such as an ultraviolet absorber, a light stabilizer, a lubricant, a release agent, a filler, a coloring agent and a plasticizer are added, and these additives are commonly used vinyl chloride resins. Can be added in the same manner as described above.

The above-mentioned vinyl chloride resin is molded in the same manner as a commonly used vinyl chloride resin such as an extrusion molding method, an injection molding method, a blow molding method, a vacuum molding method, a calender molding method, a press molding method and the like. it can.

According to a second aspect of the present invention, 100 parts by weight of a (meth) acrylate monomer having a secondary transition point of a homopolymer of -140 to -20 ° C and 0.1 to 0.1 of a polyfunctional monomer are used.
On a core particle surface layer obtained by copolymerizing 30 parts by weight, 100 parts by weight of a radical polymerizable vinyl monomer containing an epoxy group-containing radical polymerizable vinyl monomer and 0 to 30 parts by weight of a polyfunctional monomer are graft-copolymerized. Core / shell structured acrylic copolymer particle surface layer,
A vinyl chloride resin characterized in that vinyl chloride or a vinyl monomer mainly composed of vinyl chloride is graft-copolymerized in a ratio of 99 to 40% by weight to 1 to 60% by weight of the acrylic copolymer particles. Is the gist.

The homopolymer has a Tg of -140 to -20.
The (meth) acrylate-based monomer having a temperature of ° C.
The (meth) acrylate monomer used in the described invention is used in the same manner. Further, the Tg of the homopolymer of the (meth) acrylate monomer used is -140 to
The reason for limiting the temperature to −20 ° C. is also due to the reason described in the first aspect of the present invention.

As the polyfunctional monomer, the polyfunctional monomer used in the first aspect of the present invention is similarly used. Further, the copolymerization ratio of the polyfunctional monomer used is based on 100 parts by weight of the above (meth) acrylate monomer.
The reason for limiting the amount to 0.1 to 30 parts by weight is also based on the reason described in the first aspect of the present invention.

The homopolymer has a Tg of -140 to -20.
The method for obtaining an acrylic copolymer from 100 parts by weight of a (meth) acrylate-based monomer and 0.1 to 30 parts by weight of a polyfunctional monomer at a temperature of 0 ° C is not particularly limited. The method used in the present invention can be used similarly.

The acrylic copolymer according to the present invention comprises 2
Acrylic copolymer fine particles obtained by the above polymerization reaction are used as a core, and a radical polymerizable vinyl monomer containing an epoxy group-containing radical polymerizable vinyl monomer is formed on the core particle surface layer in an amount of 100 parts by weight. Acrylic copolymer particles having a core / shell two-layer structure obtained by graft copolymerizing 0 to 30 parts by weight of a polyfunctional monomer.
Even when a polyfunctional monomer is used only for the core particles, it is possible to obtain physical properties such as impact resistance as a resin.

The radical polymerizable vinyl monomer containing the epoxy group-containing radical polymerizable vinyl monomer contains at least 3% by weight or more of the epoxy group-containing radical polymerizable vinyl monomer. It may be a vinyl monomer. As the epoxy group-containing radical polymerizable vinyl monomer, the epoxy group-containing radical polymerizable vinyl monomer used in the first aspect of the present invention is similarly used. The radical polymerizable vinyl monomer other than the epoxy group-containing radical polymerizable vinyl monomer is not particularly limited as long as it can be copolymerized with the epoxy group-containing radical polymerizable vinyl monomer. Aromatic vinyls such as α-methylstyrene, acrylic acid or its esters, acrylic monomers such as acrylamide, nitrile group-containing monomers such as acrylonitrile and 2,4-dicyanobutene, vinyl ester monomers such as vinyl acetate, isoprene And diene monomers such as butadiene, other olefins, unsaturated esters, halogenated olefins, and vinyl ethers. These may be used alone or in combination of two or more.

The radical polymerizable vinyl monomer 10 containing the above-mentioned epoxy group-containing radical polymerizable vinyl monomer.
The method of graft-copolymerizing 0 parts by weight and 0 to 30 parts by weight of the polyfunctional monomer is not particularly limited.
For example, the method used in the invention described in claim 1 can be similarly used.

The graft copolymer of the acrylic copolymer fine particles forming the core of the first layer and the epoxy group-containing radical polymerizable monomer and the polyfunctional monomer forming the shell of the second layer is formed of the first layer. The polymerization may be continuously performed in the same polymerization step as the polymerization of the acrylic copolymer fine particles forming the core. The continuous polymerization reaction includes, for example, a method in which an emulsion monomer liquid constituting a plurality of layers from a core portion to a shell portion is supplied in the order of the constitution, and the polymerization is sequentially performed.
By adjusting the blending ratio of the polymerizable monomer composition forming the core of the first layer and the polymerizable monomer composition forming the shell of the second layer, the core having the above-mentioned specific configuration is adjusted.
A shell two-layer structure can be adopted.

The acrylic copolymer thus obtained has the above-mentioned acrylic copolymer fine particles as a core,
The core particle surface layer has a structure in which a radical polymerizable vinyl monomer containing an epoxy group-containing radical polymerizable vinyl monomer and a shell layer obtained by graft copolymerization of a polyfunctional monomer are covered, and constitutes an interface between the two layers. The monomer of the component of the second layer is graft-copolymerized with the monomer of the component of the first layer, and the interface between the two layers is firmly compatible and bonded.

Next, 99 to 40 parts by weight of vinyl chloride or a vinyl monomer mainly composed of vinyl chloride is graft-copolymerized with 1 to 60 parts by weight of the acrylic polymer. As the vinyl monomer graft-copolymerized with the vinyl chloride, the vinyl monomer used in the first aspect of the present invention can be used similarly. The amount of the vinyl monomer to be graft-copolymerized is the same as in the first aspect of the present invention.

The method for obtaining a vinyl chloride-based graft copolymer by graft-copolymerizing vinyl chloride with the acrylic polymer may be the same as the polymerization means used in the first aspect of the present invention. The reason why the graft copolymerization amount of the acrylic polymer and vinyl chloride or a vinyl monomer mainly composed of vinyl chloride is limited to the above range is also due to the reason described in the first aspect of the present invention.

In the vinyl chloride resin according to the first aspect of the present invention, the epoxy group-containing radically polymerizable vinyl monomer has a homopolymer having a Tg of -140 to -20 ° C and a (meth) acrylate monomer and a polyfunctional monomer. A vinyl monomer having vinyl chloride or vinyl chloride as a main component is graft-copolymerized to an acrylic copolymer having a specific structure consisting of: and the acrylic copolymer has a crosslinked structure. Has excellent impact resistance. Further, the vinyl chloride resin according to the first aspect of the present invention has excellent thermal stability at the time of molding because the epoxy group contained in the vinyl chloride resin molecule supplements hydrogen chloride.

The vinyl chloride resin according to the second aspect of the present invention is preferably composed of a (meth) acrylate monomer and a polyfunctional monomer having a homopolymer having a Tg of -140 to -20 ° C in the innermost layer. By using it as a core component, it is a sanitary material that suppresses surface stickiness and the like derived from having a large amount of rubber components, and, on the core layer, the epoxy group-containing radical polymerizable vinyl monomer. A shell layer obtained by graft copolymerization of a radical polymerizable vinyl monomer and a polyfunctional monomer is formed in contact with the vinyl chloride layer, and the epoxy groups introduced into the vinyl chloride resin molecules are unevenly distributed in the shell layer. In addition to those that improve the thermal stability during molding more effectively, the resulting molded article has excellent impact resistance and an excellent balance between flexibility and rigidity Going on.

[0037]

Embodiments of the present invention will be described below. (Examples 1 to 3), (Comparative Examples 1 to 8) [Preparation of Acrylic Copolymer A] A predetermined amount of pure water was placed in a reaction vessel equipped with a stirrer and a temperature controller, and the inside of the vessel was replaced with nitrogen. Then, the temperature of the reaction vessel was raised to 75 ° C. with stirring, and then a polymerization initiator (ammonium persulfate, hereinafter abbreviated as APS) was charged. Separately, according to the composition shown in Table 1, emulsified dispersant (polyoxyethylene nonyl phenyl ether ammonium sulfate) and glycidyl methacrylate (hereinafter referred to as GMA) as a radical polymerizable vinyl monomer containing an epoxy group in a predetermined amount of pure water. Glycidyl acrylate (hereinafter abbreviated as GA), n-butyl acrylate (Tg = −54 ° C., hereinafter abbreviated as nBA), methyl methacrylate (Tg = 108 ° C., below) as an acrylic monomer. MMA) and trimethylolpropane triacrylate (hereinafter abbreviated as TMPTA) as a polyfunctional monomer were dispersed to prepare an emulsion monomer liquid. Next, the above-mentioned emulsified monomer liquid was dropped into the reaction vessel at a constant speed while stirring, and the entire emulsified monomer liquid was dropped in 3 hours. After completion of the dropwise addition, stirring was further continued for 1 hour to terminate the polymerization reaction, thereby preparing an acrylic copolymer A having a solid content of about 30% by weight (hereinafter abbreviated as latex A).

[Preparation of Vinyl Chloride Resin] The obtained latex A was placed in a reaction vessel equipped with a stirrer and a temperature controller.
According to the composition shown in Tables 3 and 4, a predetermined amount of pure water, a dispersant (3% by weight aqueous solution of partially saponified polyvinyl acetate), a polymerization initiator (t-butylperoxy neodecanoate and α) -Cumyl peroxy neodecanoate), and after the air in the reaction vessel was evacuated with a vacuum pump, vinyl chloride monomer was added with stirring,
The polymerization was started by controlling the inside of the reaction vessel to 64 ° C. Except for Comparative Examples 7 and 8, the vinyl chloride monomer polymerization ratio (% by weight) in the above Examples and Comparative Examples was set to 92% by weight. The completion of the reaction was confirmed when the pressure in the reaction vessel dropped to a predetermined pressure, and the unreacted vinyl chloride monomer was discharged to produce a vinyl chloride resin. The polymerization degree of the obtained vinyl chloride resin was about 800.

[0039]

[Table 1]

(Examples 4 to 7) and (Comparative Examples 9 to 15) A reaction vessel was prepared in the same manner as in Example 1, a predetermined amount of pure water was charged, the inside of the vessel was replaced with nitrogen, and the reaction vessel was stirred. Is raised to 75 ° C., and then a polymerization initiator (ammonium persulfate; hereinafter,
APS). Separately, according to the composition shown in Table 2, the emulsified monomer liquid for forming the core particles of the first layer is dispersed in a predetermined amount of pure water with an emulsified dispersant, nBA, and TMPTA, and the emulsified monomer liquid is dispersed. Was prepared.
Further, the emulsified monomer liquid for forming the shell layer of the second layer is similarly dissolved in a predetermined amount of pure water as an emulsifying dispersant and an epoxy group-containing radically polymerizable vinyl monomer as GMA, GA, and GMA and GA. An emulsified monomer solution was prepared by dispersing MMA as a copolymerizable vinyl monomer and TMPTA as a polyfunctional monomer.

Next, the above-mentioned emulsified monomer liquid for forming the first layer is dropped into the reaction vessel at a constant speed with stirring.
In the same manner, the whole emulsion monomer liquid was dropped in 3 hours. After completion of the dropwise addition, stirring was further continued for 1 hour to terminate the polymerization reaction, thereby preparing an acrylic copolymer B having a solid content of about 30% by weight (hereinafter abbreviated as latex B).

[0042]

[Table 2]

[Preparation of Vinyl Chloride Resin] The obtained latex B was placed in a reaction vessel equipped with a stirrer and a temperature controller.
According to the composition shown in Tables 3 to 5, a predetermined amount of pure water, a dispersant (3% by weight aqueous solution of partially saponified polyvinyl acetate),
After the polymerization initiators (t-butyl peroxy neodecanoate and α-cumyl peroxy neodecanoate) were charged together, the air in the reaction vessel was exhausted with a vacuum pump, and then vinyl chloride was stirred. The monomer was added, and the polymerization was started by controlling the inside of the reaction vessel to 64 ° C. Comparative Example 1
Except for Comparative Example 4 and Comparative Example 15, the vinyl chloride monomer polymerization ratio (% by weight) in the above Examples and Comparative Examples was set to 92% by weight. The completion of the reaction was confirmed when the pressure in the reaction vessel dropped to a predetermined pressure, and the unreacted vinyl chloride monomer was discharged to produce a vinyl chloride resin. The polymerization degree of the obtained vinyl chloride resin was about 800.

(Preparation of Sample) To 100 parts by weight of each of the obtained vinyl chloride resins, 1 part by weight of an organotin-based stabilizer (trade name “Stann ONZ-142F” manufactured by Sankyoki Gosei Co., Ltd.) and montanic acid 0.5 part by weight of a system-based lubricant (trade name “WAX-OP” manufactured by Hoechst Japan Co., Ltd.) was added and mixed for 5 minutes using a Henschel mixer, and the obtained vinyl chloride-based resin composition was mixed with an 8-inch mixing roll. At 19
Kneading at 0 ° C. for 3 minutes to form a 1 mm thick sheet,
A test piece of 0 mm × 30 mm was cut out to prepare a sample for a thermal stability test.

The above vinyl chloride resin sheet for thermal stability test was heated at 200 ° C. for 3 minutes using a press forming machine, and then pressed at a surface pressure of 70 kg / cm ² for 3 minutes to obtain a 3 mm-thick impact resistance. A sample for a sex test was prepared.

(Evaluation of Performance) In order to evaluate the performance of the vinyl chloride resin, the test pieces were tested for thermal stability and impact resistance by the following methods. Table 3 ~
It is shown in FIG.

1. Thermal Stability: The sample was heated in a gear oven at 180 ° C. and measured at 10 minute intervals as the time to decompose the time at which the sample became apparently black or began to develop black spots.

2. Impact resistance: A Charpy impact test at 23 ° C. was performed according to JIS K 7111 to measure impact strength.

[0049]

[Table 3]

[0050]

[Table 4]

[0051]

[Table 5]

[0052]

As described above, the vinyl chloride resin according to the first aspect of the present invention is a (meth) acrylate having a homopolymer of an epoxy group-containing radically polymerizable vinyl monomer having a Tg of -140 to -20 ° C. A vinyl monomer mainly composed of vinyl chloride or vinyl chloride is graft-copolymerized to an acrylic copolymer having a specific structure composed of a system monomer and a polyfunctional monomer, and the acrylic copolymer is
Since the crosslinked structure is formed, the molded article has excellent impact resistance. Furthermore, the vinyl chloride resin of the invention according to claim 1 is:
Since the epoxy group contained in the vinyl chloride resin molecule supplements hydrogen chloride, it has excellent thermal stability during molding.

The vinyl chloride resin according to the second aspect of the present invention is preferably composed of a (meth) acrylate monomer and a polyfunctional monomer having a homopolymer having a Tg of -140 to -20 ° C. in the innermost layer. By using it as a core component, it is a hygienic material that suppresses surface stickiness and the like derived from having a large amount of rubber components, and, on the core layer, the epoxy group-containing radical polymerizable vinyl. A shell layer obtained by graft copolymerizing a radical polymerizable vinyl monomer containing a monomer and a polyfunctional monomer is formed in contact with the vinyl chloride layer, and the epoxy groups introduced into the vinyl chloride resin molecules are unevenly distributed in the shell layer. Because
The thermal stability at the time of molding is more effectively improved, and the obtained molded article is excellent in impact resistance and excellent in balance between flexibility and rigidity.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 214: 06)

Claims (2)

[Claims] An epoxy group-containing radically polymerizable vinyl monomer of 5 to 50% by weight and a homopolymer having a secondary transition point of-
1 to 60 parts by weight of an acrylic copolymer consisting of 100 parts by weight of a mixed monomer composed of 95 to 50% by weight of a (meth) acrylate-based monomer at 140 to -20 ° C and 0.1 to 30 parts by weight of a polyfunctional monomer. A vinyl chloride resin characterized in that vinyl chloride or vinyl chloride or a vinyl monomer mainly containing vinyl chloride in an amount of 99 to 40 parts by weight is graft-copolymerized. 2. The homopolymer has a secondary transition point of -140 to-
Radical polymerization containing an epoxy group-containing radically polymerizable vinyl monomer on a core particle surface layer obtained by copolymerizing 100 parts by weight of a (meth) acrylate monomer at 20 ° C. and 0.1 to 30 parts by weight of a polyfunctional monomer. Vinyl chloride or vinyl chloride as a main component on the surface layer of an acrylic copolymer particle having a core / shell structure obtained by graft copolymerizing 100 parts by weight of a functional vinyl monomer and 0 to 30 parts by weight of a polyfunctional monomer. The vinyl monomer is 99 to 40% by weight based on 1 to 60% by weight of the acrylic copolymer particles.
A vinyl chloride resin characterized by being graft-copolymerized at a ratio of: