JPH04272952A - Vinyl chloride resin composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 composition having excellent impact resistance.

0002

BACKGROUND OF THE INVENTION Vinyl chloride resins have various excellent chemical and physical properties and are inexpensive, so they are produced in large quantities and widely used among synthetic resins. However, molded products of vinyl chloride resins have a major drawback of being brittle against impacts, and great efforts have been made to overcome this drawback, and numerous technical improvements have been made.

For example, a method in which a graft copolymer obtained by graft polymerizing monomers such as styrene, acrylonitrile, and methyl methacrylate to a rubber-like elastomer is mixed with a vinyl chloride resin (Japanese Patent Publication No. 56-22339, No. 5)
No. 7-26536, No. 60-27689, etc.), and such graft copolymers are already commercially available as impact modifiers for vinyl chloride resins, and are expected to expand the use of vinyl chloride resin products. has made a major contribution.

[0004] However, in order to improve the impact resistance of vinyl chloride resins, it is necessary to incorporate relatively large amounts of these impact resistance modifiers, which may impair the original excellent properties of vinyl chloride resins. Therefore, there is a demand for the development of an impact modifier for vinyl chloride resins that exhibits high impact resistance with a small amount of addition.
A silicone-acrylic composite rubber is proposed in Japanese Patent No. 279954.

[0005]

[Problem to be solved by the invention] However, silicone
Graft copolymers using acrylic composite rubber have excellent impact resistance, but they have the drawback of poor colorability with pigments, which limits their application. Currently, there is a strong demand for an impact modifier for vinyl chloride resins that can exhibit high impact resistance with a small amount added.

[0006]

[Means for Solving the Problem] In view of the above circumstances, the present inventors have developed an impact resistance modifier for vinyl chloride resin that has excellent impact resistance, surface gloss, and colorability with dyes and pigments. As a result of intensive studies, we have integrated the polyorganosiloxane rubber component obtained by simultaneously performing emulsion polymerization of organosiloxane and emulsion polymerization of vinyl monomer with the polyalkyl (meth)acrylate rubber component so that they cannot be separated. A polyorganosiloxane-based composite rubber with a structure in which a vinyl monomer is graft-polymerized maintains the excellent impact resistance imparting effect derived from the polyorganosiloxane rubber, and has the ability to be colored with the dyes and pigments derived from this rubber. It was discovered that the impact resistance modifier for vinyl chloride resins has improved properties, and the present invention was achieved.

That is, the gist of the present invention is (1) a vinyl chloride resin, (2) an organosiloxane and a crosslinking agent for polyorganosiloxane rubber (hereinafter referred to as crosslinking agent (I)), and optionally a graft for polyorganosiloxane rubber. Emulsion polymerization with a cross-agent (hereinafter referred to as graft cross-agent (I)) and at least one radically polymerizable vinyl monomer (A)
One or more vinyl monomers are added to a composite rubber having a structure in which a polyorganosiloxane rubber component and a polyalkyl (meth)acrylate rubber component are integrated so that they cannot be separated. (B)
A vinyl chloride-based resin composition containing as a main component a composite rubber-based graft copolymer obtained by graft polymerization.

The vinyl chloride resin used in the present invention is a homopolymer of vinyl chloride or a copolymer of 80% by weight or more of vinyl chloride and 20% by weight or less of other vinyl monomers that can be copolymerized with vinyl chloride. Examples of other vinyl monomers include vinyl acetate, ethylene, acrylic ester, and vinyl bromide.

[0009] Furthermore, the composite rubber graft copolymer used in the present invention is a composite rubber having a structure in which a polyorganosiloxane rubber component and a polyalkyl (meth)acrylate rubber component are integrated so that they cannot be separated. Monomer (B) is graft-polymerized, and this polyorganosiloxane rubber component is composed of organosiloxane, crosslinking agent (I), and optional graft crosslinking agent (I).
It is obtained by simultaneously carrying out emulsion polymerization of a polyvinyl monomer and an emulsion polymerization of at least one radically polymerizable vinyl monomer in a state in which both are mixed.

[0010] This composite rubber is preferably composed of 1 to 90% by weight of a polyorganosiloxane rubber component and 99 to 10% by weight of a polyalkyl (meth)acrylate rubber component, both components being 10 to 90% by weight. % is more preferable. When the polyorganosiloxane rubber component exceeds 90% by weight in the composite rubber, the surface appearance of the molded product obtained from the composition deteriorates, and when it exceeds 1% by weight, the impact resistance of the composition decreases. be.

The number average particle size of the composite rubber used in the present invention is 0.
．． 08 to 0.6 μm, preferably 0.1 to 0
．． More preferably, the thickness is in the range of 4 μm. The particle size is 0
．． If it is smaller than 0.08 μm, the impact resistance of the resulting composition tends to decrease, and if it is larger than 0.6 μm, the impact resistance of the resulting composition tends to decrease and the appearance of the surface of the molded product tends to deteriorate.

Emulsion polymerization is the most suitable method for obtaining a composite rubber having such a number average particle size, and in the present invention, the polyorganosiloxane rubber component, which is one component of the composite rubber, is produced by emulsion polymerization.

The polyorganosiloxane rubber, which is one of the components constituting the polyorganosiloxane rubber component, is produced by emulsion polymerization of organosiloxane, a crosslinking agent (I), and optionally an optional grafting agent (I). It is obtained by

Examples of the organosiloxane include cyclic organosiloxanes having three or more membered rings, and those having three to six membered rings are preferably used. Specific examples of preferred cyclic organosiloxane include hexamethylcyclotrisiloxane,
Octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane,
tetramethyltetraphenylcyclotetrasiloxane,
Examples include octaphenylcyclotetrasiloxane,
These may be used alone or in combination of two or more. The amount of cyclic organosiloxane used is preferably 60% by weight or more in the polyorganosiloxane rubber, and 70% by weight or more.
More preferably, it is at least % by weight.

As the crosslinking agent (I), a trifunctional or tetrafunctional silane crosslinking agent, that is, a silane compound having three or four alkoxy groups, is used, specific examples of which include trimethoxymethylsilane, triethoxysilane, etc. Examples include phenylsilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, and tetrabutoxysilane. As the crosslinking agent (I), a tetrafunctional one is preferable, and among the tetrafunctional crosslinking agents, tetraethoxysilane is particularly preferable. The amount of crosslinking agent (I) used is preferably 0.1 to 30% by weight, more preferably 0.5 to 10% by weight, based on the polyorganosiloxane rubber.

What is the graft cross-agent (I)? The siloxane portion thereof participates in polymerization and is incorporated into the polyorganosiloxane rubber, but it does not react at this time and remains in the polyorganosiloxane rubber for subsequent graft polymerization or composite rubber preparation. It is a siloxane having a functional group that reacts during the polymerization for poly(meth)acrylate rubber described below.

[0017]

[Chemical formula 1]

(In each formula, R1 represents a methyl group, ethyl group, propyl group or phenyl group, R2 represents a hydrogen atom or a methyl group, n represents 0, 1 or 2, and p represents an integer from 1 to 6.)
A compound etc. that can form a unit represented by is used.

Among these, (meth)acryloyloxysiloxane that can form the unit of formula (I-1) has a high grafting efficiency, so it is possible to form an effective graft chain, and it has a high grafting efficiency. It is advantageous. Furthermore, the formula (I
Methacryloyloxysiloxane is particularly preferred as a compound capable of forming the unit -1).

Specific examples of methacryloyloxysiloxane include β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-methacryloyloxypropyldimethoxymethylsilane. Examples include methacryloyloxypropylethoxydiethylsilane, γ-methacryloyloxypropyldiethoxymethylsilane, δ-methacryloyloxybutyldiethoxymethylsilane, and among these, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropyldiethoxymethylsilane, Methoxysilane is more preferred.

Examples of compounds that can form units of formula (I-2) include vinyltrimethoxysilane and vinylmethyldimethoxysilane, and examples of compounds that can form units of formula (I-3) include 4-vinyl Examples include phenyldimethoxymethylsilane, 4-vinylphenyltrimethoxysilane, etc., and examples that can form the unit of formula (I-4) include γ
Examples include -mercaptopropyldimethoxymethylsilane, γ-mercaptopropyltrimethoxysilane, and γ-mercaptopropyldiethoxyethylsilane. The amount of grafting agent (I) used is 0.1 to 10% by weight in the polyorganosiloxane rubber.

When carrying out the emulsion polymerization of the organosiloxane, at least one kind of radically polymerizable vinyl monomer (A) is coexisting, and a radical polymerization initiator is added and allowed to act, thereby achieving the emulsion polymerization of the organosiloxane. This emulsion polymerization of the vinyl monomer is carried out simultaneously to finely disperse the polyorganosiloxane rubber and the vinyl polymer, thereby improving impact resistance and colorability with dyes and pigments.

Examples of the vinyl monomer (A) that can be used here include aromatic alkenyl compounds such as styrene, α-methylstyrene, and vinyltoluene; methyl methacrylate;
Methacrylic acid esters such as 2-ethylhexyl methacrylate; methyl acrylate, ethyl acrylate,
Acrylic acid esters such as butyl acrylate; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; unsaturated organic acids such as acrylic acid and methacrylic acid; various vinyl monomers such as olefins such as ethylene, propylene, butadiene, and isoprene. can be mentioned.

The vinyl monomer (A) may be a mixture of a monomer selected from the above and a polyfunctional vinyl monomer. Examples of the polyfunctional vinyl monomer include ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, Examples include divinylbenzene.

In the present invention, the polyorganosiloxane rubber is prepared by adding a mixture of the above monomer (A), organosiloxane, crosslinking agent (I), and optionally a grafting agent (I) to an alkylbenzene sulfone. In the presence of an acid, a sulfonic acid emulsifier such as an alkyl sulfonic acid, emulsification is carried out by shear mixing with water using, for example, a homogenizer,
Thereafter, the temperature can be raised to start polymerization of the organosiloxane, and at the same time, a radical polymerization initiator is added and allowed to act, thereby starting the polymerization of the vinyl monomer (A).

Alkylbenzenesulfonic acids are suitable because they act as emulsifiers for organosiloxanes and at the same time act as polymerization initiators for organosiloxanes. At this time, it is preferable to use an alkylbenzenesulfonic acid together with an alkylbenzenesulfonic acid metal salt, an alkylsulfonic acid metal salt, etc., since this is effective in maintaining the polymer stably during graft polymerization.

The radical polymerization initiator used here can be a peroxide polymerization initiator, an azo polymerization initiator, a redox type initiator, etc. Hydroperoxide, Rongalit, ethylenediaminetetraacetic acid disodium salt, sulfuric acid, etc. A redox initiator such as a sulfoxylate initiator consisting of a combination of ferrous iron, a peroxide initiator such as potassium persulfate, etc. can be preferably used.

Polymerization can be terminated by cooling the latex and neutralizing it with an aqueous alkaline solution such as sodium hydroxide, potassium hydroxide, sodium carbonate or the like.

The composite rubber used in the present invention has a structure in which the polyorganosiloxane rubber component and the polyalkyl (meth)acrylate rubber component are integrated so that they cannot be separated.

The polyalkyl (meth)acrylate rubber is alkyl (meth)acrylate, a crosslinking agent for polyalkyl (meth)acrylate rubber (hereinafter referred to as crosslinking agent (II)), and a graft crosslinker for polyalkyl (meth)acrylate rubber. (hereinafter referred to as graft cross-agent (II)).

[0031] Alkyl (meth)acrylate used here
Examples include straight-chain or branched alkyl acrylates in which the alkyl group has 1 to 8 carbon atoms, and alkyl methacrylates in which the alkyl group has 6 to 12 carbon atoms. Specific examples of these include methyl acrylate. alkyl acrylates such as ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and hexyl methacrylate;
Examples include alkyl methacrylates such as 2-ethylhexyl methacrylate and n-lauryl methacrylate;
Among these, n-butyl acrylate is preferred.

As the crosslinking agent (II), a (meth)acrylate having two or more polymerizable unsaturated bonds is used,
Specific examples include ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, and 1,4-butylene glycol dimethacrylate.

The grafting cross-agent (II) is a polyalkyl (
During polymerization to produce meth)acrylate rubber, it is polymerized with other components and incorporated into the rubber, but at least some of the polymerizable unsaturated groups remain unreacted during the subsequent graft polymerization. It is a monomer having two or more polymerizable unsaturated groups with mutually different reactivity such that the remaining unsaturated group can be polymerized together with the graft branch component, and specific examples include allyl methacrylate, triallyl cyanurate, Examples include triallyl isocyanurate. In allyl methacrylate, a part of the more reactive unsaturated groups reacts during polymerization of polyalkyl (meth)acrylate rubber to form a crosslink, and the rest reacts during graft polymerization to form a graft bond. Since it forms, it functions as both a crosslinking agent (II) and a grafting agent (II).

[0034] These crosslinking agent (II) and grafting agent (II) may each be used as a single component, or two or more types of components may be used in combination. The amount of these crosslinking agent (II) and grafting agent (II) used is 0.1 to 10% by weight in the polyalkyl (meth)acrylate rubber component.
and 0.2 to 2 when allyl methacrylate alone serves as the crosslinking agent (II) and the grafting agent (II).
It is sufficient to use 0% by weight.

The polyalkyl (meth)acrylate rubber component is polymerized by adding the above polyorganosiloxane rubber latex which has been neutralized by adding an aqueous alkali solution such as sodium hydroxide, potassium hydroxide, or sodium carbonate. Alkyl (meth)acrylate, crosslinking agent (II) and grafting agent (II) are added and impregnated into polyorganosiloxane rubber particles, followed by the action of an ordinary radical polymerization initiator. As the polymerization progresses, a crosslinked network of polyalkyl (meth)acrylate rubber intertwined with the crosslinked network of the polyorganosiloxane rubber is formed, and the polyorganosiloxane rubber component and the polyorganosiloxane rubber component are integrated so as to be virtually inseparable. A composite rubber latex comprising a polyalkyl (meth)acrylate rubber component is obtained.

As a composite rubber, the main skeleton of the polyorganosiloxane rubber component has repeating units of dimethylsiloxane, and the main skeleton of the polyalkyl (meth)acrylate rubber component has repeating units derived from n-butyl acrylate. It is preferable that it has a unit.

The composite rubber thus obtained can be graft copolymerized with the vinyl monomer (B), and the polyorganosiloxane rubber component and the polyalkyl (meth)acrylate rubber component are tightly intertwined. Because it is integrated, it cannot be extracted and separated using ordinary organic solvents such as acetone or toluene. As this composite rubber, toluene is 9
Gel content is 80% when measured after extraction at 0°C for 12 hours.
The above is preferable.

Examples of vinyl monomers used in graft polymerization include aromatic alkenyl compounds such as styrene, α-methylstyrene, and vinyltoluene; methyl methacrylate,
- Methacrylic acid esters such as ethylhexyl methacrylate; Acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate; Vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; Various vinyls such as epoxy group-containing vinyl compounds such as glycidyl methacrylate Monomers can be mentioned, and these can be used alone or in combination of two or more.

The amount of the vinyl monomer in the composite rubber graft copolymer is preferably 5 to 70% by weight, and 10 to 70% by weight based on the weight of the graft copolymer.
More preferably, it is 60% by weight. If the vinyl monomer content is less than 5% by weight, the graft copolymer will not be sufficiently dispersed in the resin and impact resistance will tend to be insufficient.
Moreover, if it exceeds 70% by weight, the rubber content decreases and the effect of developing impact resistance tends to decrease.

The graft copolymer used in the present invention is produced by adding the above vinyl monomer (B) to a composite rubber latex and polymerizing it in one stage or in multiple stages using radical polymerization technology, and then producing the composite rubber graft copolymer thus obtained. Polymer latex can be separated and recovered by pouring into hot water in which metal salts such as calcium chloride and magnesium sulfate are dissolved, followed by salting out and coagulation.

In the vinyl chloride resin composition of the present invention, the above-mentioned composite rubber graft copolymer accounts for 2% of the total resin composition.
It is preferable that the content is in the range of 40% by weight. If it is less than 2% by weight, the effect of improving the impact strength of the vinyl chloride resin tends to be insufficient, and if it exceeds 40% by weight, although the impact resistance is good, it tends to be uneconomical. .

The vinyl chloride resin and the composite rubber graft copolymer are mixed using a conventional kneading machine. Such machines include mixing rolls, calender rolls, Banbury mixers, extruders, blow molding machines, inflation molding machines, and the like.

Furthermore, dyes/pigments, stabilizers, reinforcing agents, fillers, flame retardants, etc. can be added to the vinyl chloride resin composition of the present invention, if necessary.

[0044]

[Example] The present invention will be specifically explained by the following example. In the following description, all "parts" mean parts by weight. The physical properties in each Example and Comparative Example were measured by the following methods. Average particle size: Using latex diluted with water as a sample solution, quasi-elastic light scattering method (MA
LVERN SYSTEM 4600, measurement temperature 25
℃, scattering angle 900). Izod impact strength: According to the method of ASTM D-256. (With 1/4" notch) Color measurement: According to the method of JIS Z-8729. (Method of displaying object color using L* a* b* color system) Note that L* value of 15 or less is good, and 20 It is said that the above may cause problems in practice. Gel content of composite rubber used for graft polymerization: 90°C in toluene, 12
It was determined by extracting the time.

Reference Example 1 Production of composite rubber-based graft copolymer (S-1): 2 parts of tetraethoxysilane, 0.5 part of γ-methacryloyloxypropyldimethoxymethylsilane and 92 parts of octamethylcyclotetrasiloxane were mixed. 94.5 parts of a siloxane mixture was obtained. A mixture of 5 parts of styrene and 0.5 parts of divinylbenzene was added to this mixture. Next, prepare 200 parts of distilled water in which 1 part each of dodecylbenzenesulfonic acid and sodium dodecylbenzenesulfonate is dissolved,
100 parts of the above-mentioned siloxane/styrene mixture was added, preliminarily stirred at 10,000 rpm using a homomixer, and then emulsified using a homogenizer at a pressure of 300 kg/cm2 to obtain an organosiloxane/styrene mixed latex. This latex was transferred to a separable flask equipped with a condenser and stirring blades, and the temperature was raised to 80°C while stirring and mixing.
of the aqueous solution and heated for 5 hours, then heated for 20 hours for 48 hours.
After being allowed to stand at ℃, the pH of this latex was neutralized to 6.9 with an aqueous sodium hydroxide solution to obtain a polyorganosiloxane rubber latex (hereinafter referred to as PDMS-1). The polymerization rate to the obtained polyorganosiloxane rubber was 8
The average particle diameter of the polyorganosiloxane rubber was 0.21 μm, and the concentration of solid content (polyorganosiloxane rubber) in the latex was 30.0%.

67 parts of this PDMS-1 was collected, put into a separable flask equipped with a stirrer, 53 parts of distilled water was added, the atmosphere was replaced with nitrogen, the temperature was raised to 50°C, and 58 parts of n-butyl acrylate was added. A mixed solution of 0.8 parts of allyl methacrylate, 1.2 parts of allyl methacrylate, and 0.24 parts of ter-butyl hydroperoxide was charged and stirred for 30 minutes to allow this mixed solution to penetrate into the polyorganosiloxane rubber particles. Next, a mixed solution of 0.002 parts of ferrous sulfate, 0.006 parts of ethylenediaminetetraacetic acid disodium salt, 0.26 parts of Rongalite, and 5 parts of distilled water was charged to start radical polymerization, and then kept at an internal temperature of 70°C for 2 hours. A composite rubber latex was obtained. A portion of this latex was sampled and the number average particle size of the composite rubber was measured and found to be 0.29 μm. Further, a part of this latex was dried to obtain a solid substance, and the gel content was measured and found to be 94.1% by weight.

A mixed solution of 20 parts of methyl methacrylate and 0.12 parts of tert-butyl hydroperoxide was added dropwise to this composite rubber latex over 15 minutes.
Thereafter, the mixture was maintained at 70° C. for 4 hours to perform graft polymerization into a composite rubber. The polymerization rate of methyl methacrylate is 96
．． 5%, and the average particle size of the graft copolymer is 0.20.
It was μm. The obtained graft copolymer latex was dropped into 200 parts by weight of hot water containing 1.5% by weight of calcium chloride, coagulated and separated, and washed with water repeatedly.
After drying at ℃ for 16 hours, the composite rubber-based graft copolymer (S
-1) 92.9 parts by weight of dry powder was obtained.

Reference Examples 2 to 5 Polyorganosiloxane-based graft copolymers (S-2 to
5) Production: The amount of PDMS-1 collected, the amount of distilled water added, the amount of n-butyl acrylate and allyl methacrylate, and the amount of tert-butyl hydroperoxide added in the composite rubber polymerization were as shown in Table 1. A composite rubber latex was obtained in the same manner as in Reference Example 1, except that these were used, and graft polymerization to the composite rubber was carried out in the same manner as in Reference Example 1, and the obtained latex was coagulated, separated, and dried. Composite rubber-based graft copolymer (S-2 to S
-5) was obtained. The number average particle size and gel content of composite rubber are shown.

[0049]

[Table 1]

Reference Examples 6 to 9 Reference examples except that octamethyltetrasiloxane, tetraethoxysilane, γ-methacryloyloxypropyldimethoxymethylsilane and styrene, divinylbenzene or acrylonitrile were used as the vinyl monomer in the amounts shown in Table 2. A polyorganosiloxane rubber latex was obtained in the same manner as in Example 1, a composite rubber was obtained in the same manner as in Reference Example 1 except that these rubber latexes were used, and graft polymerization was carried out in the same manner to obtain a composite rubber graft. A polymer was obtained. The concentration of the polyorganosiloxane rubber component (solid content) in the polyorganosiloxane rubber latex used in the synthesis of these composite rubbers was 30.0.
%Met.

[0051]

[Table 2]

Reference Example 10 A composite rubber was obtained in the same manner as in Reference Example 1, except that 53 parts of distilled water was not added during the production of composite rubber by polymerization in the presence of polyorganosiloxane rubber latex. The number average particle size of the composite rubber was 0.21 μm, and the gel content was 95.8% by weight. This composite rubber latex
A mixture of 0.1 part of ert-butyl hydroperoxide and 10 parts of styrene was added dropwise at 70°C over 20 minutes.
Thereafter, after holding at 70°C for 2 hours, a mixture of 0.1 part of tert-butyl hydroperoxide and 10 parts of methyl methacrylate was added dropwise at 70°C over 20 minutes, then held at 70°C for 2 hours, and then A composite rubber graft copolymer (S-
10) Dry powder was obtained.

Reference Example 11 2 parts of tetraethoxysilane, 97.5 parts of octamethyltetrasiloxane and 0.5 part of γ-methacryloyloxypropyldimethoxymethylsilane were mixed to obtain 100 parts of a siloxane mixture. Next, add 1 portion each of dodecylbenzenesulfonic acid and sodium dodecylbenzenesulfonate.
Prepare 200 parts of distilled water, add 100 parts of the above siloxane mixture, and mix with a homomixer to 10.0 parts of distilled water.
After pre-stirring at 00 rpm, the homogenizer
After emulsifying at a pressure of 00 kg/cm2 and heating at 80°C for 5 hours, it was cooled and kept at 20°C for 48 hours.
The mixture was then neutralized to pH 7.0 with sodium hydroxide to obtain a polyorganosiloxane rubber latex. Polymerization rate is 89
．． 1%, and the number average particle size was 0.24 μm. P
A composite rubber latex was obtained in the same manner as in Reference Example 1 except that the same amount of the polyorganosiloxane rubber latex obtained above was used instead of DMS-1. The composite rubber had a number average particle size of 0.30 μm and a gel content of 96.1% by weight. A composite rubber-based graft copolymer dry powder was obtained in the same manner as in Reference Example 1 except that this composite rubber latex was used.

Reference Example 12 195 parts of distilled water in which 1 part of sodium dodecylbenzenesulfonate was dissolved was placed in a separable flask equipped with a stirrer, and 97 parts of n-butyl acrylate, 3 parts of allyl methacrylate, and tert-butyl hydrochloride were added. A mixed solution consisting of 0.24 parts of peroxide was added and emulsified, and after nitrogen purging, the temperature was raised to 60°C, and 0.002 parts of ferrous sulfate was added.
parts, ethylenediaminetetraacetic acid disodium salt 0.006
A mixture of 0.26 parts of Rongalit, 0.26 parts of distilled water, and 5 parts of distilled water was charged to initiate radical polymerization, and the internal temperature was then maintained at 70° C. for 2 hours to obtain a polybutyl acrylate rubber latex.

182 parts of this polybutyl acrylate rubber latex and PDMS-1 obtained in the same manner as in Reference Example 1
This was placed in a separable flask equipped with a stirrer, heated to 70°C, and 0.0% of ferrous sulfate was added.
0013 parts, ethylenediaminetetraacetic acid disodium salt 0
．． 0.004 parts of Rongalit, and 5 parts of distilled water were charged, and then a mixed solution of 20 parts of methyl methacrylate and 0.1 part of tert-butyl hydroperoxide was added dropwise at 70°C over 15 minutes. A latex of graft copolymer S-12 onto a mixed rubber of polyorganosiloxane rubber and polybutyl acrylate rubber was obtained. The polymerization rate of methyl methacrylate was 95.8%. This latex was dropped into 300 parts of hot water containing 1.5% by weight of calcium chloride, coagulated, separated, and washed.
It was dried at ℃ for 16 hours to obtain 98 parts of dry powder.

Examples 1 to 9, Comparative Examples 1 to 3 A mixture 10 obtained by mixing 90 parts of a polyvinyl chloride resin with a degree of polymerization of 70 and 10 parts each of the graft copolymers obtained in Reference Examples 1 to 12.
Add 3 parts of dibutyltin maleate, 1 part of butyl stearate, 0.5 parts of stearyl alcohol, and 0.5 parts of carbon black (manufactured by Cabot, V-9) to 0 parts, mix for 5 minutes with a Henschel mixer, Extrusion was performed at 170° C. using an extruder equipped with a 4” square bar die to produce a 1/4” profile extruded bar. This rod was provided with a V-notch and subjected to an Izod impact test, and the results shown in Table 3 were obtained. Further, the colorability of this irregularly shaped extruded rod was measured by a colorimetric test, and the results shown in Table 3 were obtained.

[0057]

[Table 3]

From the results in Table 3, when the polyorganosiloxane rubber component does not contain a polymer derived from a radically polymerizable vinyl monomer (Comparative Example 2), the polyorganosiloxane rubber component and polyalkyl (meth)acrylate It can be seen that even though the rubber component is composite and the impact resistance is excellent, the coloring property with carbon black is poor. Furthermore, it can be seen that when the polyorganosiloxane rubber and the polyalkyl (meth)acrylate rubber are not composited (Comparative Example 3), both the impact strength and the pigment colorability are low. It is also found that when the polyorganosiloxane rubber component in the composite rubber exceeds 90% by weight, the pigment colorability decreases.

Furthermore, the radically polymerizable vinyl monomer in the polyorganosiloxane rubber component can be simultaneously polymerized with the polyorganosiloxane over a wide range of compositions, and the compositions obtained using them have good impact resistance. It can be seen that the pigment coloring properties are excellent.

[0060]

Effects of the Invention As described above, the vinyl chloride resin composition of the present invention is characterized by excellent impact resistance and pigment colorability.

[0061] Preferred embodiments of the present invention are as follows. 1) The vinyl chloride resin composition according to claim 1, wherein the gel content of the composite rubber measured by toluene extraction is 80% by weight or more. 2) The vinyl chloride resin composition according to claim 1, wherein the composite rubber has a number average particle size of 0.08 to 0.6 μm. 3) The main skeleton of the polyorganosiloxane rubber constituting the polyorganosiloxane rubber component has repeating units derived from dimethylsiloxane, and the main component of the vinyl polymer of the radically polymerizable vinyl monomer (A) is styrene. 2. The vinyl chloride resin composition according to claim 1, wherein the main skeleton of the polyalkyl (meth)acrylate rubber component has a repeating unit derived from n-butyl acrylate.

Claims (1)

[Claims] Claim 1: Emulsion polymerization of (1) a vinyl chloride resin and (2) an organosiloxane with a crosslinking agent for polyorganosiloxane rubber and optionally a graft crosslinking agent for polyorganosiloxane rubber, and at least one radical polymerization. Polyorganosiloxane rubber components 1 to 90 obtained by simultaneously carrying out emulsion polymerization of vinyl monomer (A)
A composite obtained by graft polymerizing one or more vinyl monomers (B) to a composite rubber having a structure in which % by weight and 99 to 10% by weight of a polyalkyl (meth)acrylate rubber component are integrated in an inseparable manner. A vinyl chloride resin composition containing a rubber-based graft copolymer as a main component.