JPS6219786B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vinyl chloride resin composition having excellent mechanical properties. Vinyl chloride resin (hereinafter abbreviated as PVC) is widely used as a general-purpose resin because it is inexpensive and has excellent physical and chemical properties. This resin is inherently hard and brittle, and easily decomposes in the processing and molding area.
It is known as a resin with poor processability. However, with the advent of other thermoplastic modifier resins that can impart flexibility, plasticity, impact resistance, and processability, these problems have been improved, and the field of application of PVC has expanded, and in recent years It has made remarkable progress.
These modifiers are typified by ABS resins, MBS resins, and acrylate resins, and many compositions made of PVC and resins containing various elastomers have also been proposed. Most of these modifiers have impact resistance,
1.3 as an elastomer component that contributes to flexibility
- Since it contains a diene elastomer such as butadiene, its physical properties such as weather resistance, discoloration resistance, and heat resistance are not satisfactory. For this reason, modifiers using saturated elastomers that do not contain double bonds in their main chains have been studied as impact resistance and flexibility improvers for PVC. These saturated elastomers are not polymers of their own.
It has low practical value due to poor compatibility with PVC, and various methods have been proposed to improve compatibility by chemically bonding other vinyl monomers that are compatible with PVC to this elastomer. . A typical example is a graft copolymer. In this case, the graft copolymer does not mean a pure graft copolymer, but for convenience refers to a polymer obtained by a so-called graft polymerization recipe in which another vinyl monomer is polymerized in the presence of a saturated elastomer. However, it is known that grafting reactions to saturated elastomers are usually extremely difficult to occur. For this reason, special studies have been made to increase the grafting reaction rate, and modifier compositions with considerably improved physical properties have been obtained. For example, a monomer having both an allyl group and a vinyl group in one molecule, such as allyl methacrylate, is bonded to the elastomer at the end of the polymerization of the elastomer polymer or after the polymerization, and another vinyl monomer is further polymerized on top of this. Attempts to improve the grafting reaction by using monomers have been known for a long time, and have recently attracted attention as so-called graft cross-monomers. Although such graft-activating monomers are certainly effective, they are also known to cause undesirable cross-linking reactions in the elastomer itself, and when the amount added is increased to increase the grafting rate, cross-linking occurs at the same time. It has the disadvantage that it also causes the reaction to proceed and reduces the impact strength and flexibility of the final product. On the other hand, it is easy to imagine that if a block copolymer is used for the same purpose as a graft copolymer, improvements in the various physical properties of PVC can be expected. Block copolymerization technology consists of (1) ionic polymerization technology;
It is broadly divided into (2) polycondensation technology, (3) radical polymerization technology, (4) polymer reaction technology, and (5) combination technology of the above.
With the exception of radical polymerization techniques, the major drawback is that the monomers (and hence polymers) are limited to special ones, require specific structures and functional groups, and require polymerization catalysts. It is not common because it requires solvents and equipment, and requires sophisticated techniques for purifying reagents, setting polymerization conditions, and performing polymerization operations.
It has the disadvantage that it is difficult to be widely adopted industrially because of the high manufacturing cost. On the other hand, the radical polymerization technique (3) is the most common technique, and the following methods are known so far. (a) A method using a special polymerization initiator (catalyst) or auxiliary agent (b) A method using a special chain transfer agent that has the ability to initiate repolymerization (c) A method that uses a special chain transfer agent that has a special functional group (photofunctionality, thermal functionality) Method using monomers (d) Method in which a vinyl compound is post-coupled to the end of a polymer (e) Method in which a radical initiator group is post-coupled to the end of a polymer (f) Method using living radicals (Tropradical) (g) Mechanical molecular cutting method (h) Ultrasonic method (i) Light irradiation flow method The method for synthesizing the block copolymer of the present invention is classified into (a) of the above radical polymerization techniques. However, the following synthesis methods using technology (a) are known so far. (1) Method using phthalyl peroxide (G.
Smets, J. Polymer Sci. 14 126 (1954)) (2) Method using diisopropylbenzene dihydroperoxide (P. Molyneux, Makromol,
Chem. 37 165 (1960)) (3) Method using 2,5-dimethylhexane 2,5-dihydroperoxide (Kobayashi, Ide, Nakatsuka, Kobunshi Kagaku 24 17 (1967)) (4) Tetraethylthiuram disulfide (T.Otsu, J.Polymer Sci. 26 236
(1957)) (5) Method using polypropylene hydroperoxide (K.Horie, Makromol, Chem. 175 2091
(1974)) (6) Method using dialkyl peroxide and specific amine (Japanese Patent Application Laid-Open No. 1984-84275) (7) Method using polyperoxide (S.
Jvanchev, Vysokomol, Soyed.A14 No.5
1027 (1972)) These synthetic methods have the following problems: synthesis of the catalyst is complicated and difficult, handling and storage are dangerous, polymerization conditions are special and the scope of application is narrow, polymerization rate is low, and molecular weight adjustment is difficult. This method involves various problems such as difficulty in obtaining a block copolymer, limitations on the monomers that can be used, and low yield of block copolymers, and has low practical value from an industrial standpoint. The present inventors have discovered that certain peroxides synthesized from cyclohexanone and hydrogen peroxide are useful in the synthesis of block copolymers, and the obtained acrylate-based elastomer block copolymers The present invention was completed based on the discovery that when mixed with PVC resin, excellent physical properties can be obtained. The present invention is based on the general formula (In the formula, R ₁ and R ₂ are each hydrogen, methyl group or ethyl group, each cyclohexanone ring can have up to three alkyl groups (methyl group and/or ethyl group), and R' is hydrogen or As the first stage polymerization, a redox catalyst consisting of a peroxide (which is a hydroxyl group) and a reducing compound that promotes the decomposition of the hydroperoxy group of the peroxide but does not easily promote the decomposition of the ketone peroxy group is used. 100 to 50% by weight of at least one alkyl acrylate having an alkyl group having 1 to 12 carbon atoms and 0 vinyl and/or vinylidene compounds copolymerizable therewith.
~50% by weight of a monomer or monomer mixture (A)
100 parts by weight is polymerized, and then as a second stage polymerization, 100 to 50 weight % of an alkyl methacrylate having an alkyl group having 1 to 12 carbon atoms and 0 to 50 weight % of a vinyl and/or vinylidene compound copolymerizable therewith.
0.3 to 50 parts by weight of a block copolymer () obtained by polymerizing 10 to 500 parts by weight of a monomer or monomer mixture (B) consisting of and a vinyl chloride resin ()
It is a resin composition consisting of 99.7 to 50 parts by weight. In the above, the block copolymer () is the first
The present invention also includes a resin composition obtained by polymerizing the monomer or monomer mixture (B) in the step polymerization and the monomer or monomer mixture (A) in the second step polymerization. included. The formation mechanism of the block copolymer, which is a component of the present invention, is expressed as follows when R' in the general formula is OH. That is, as shown in formula (1), the reducing compound RD
selectively acts on the hydroperoxy groups of the catalyst to generate hydroxy anions and catalyst radicals. When monomer A is added to this system, A undergoes polymerization to obtain a polymer as shown in (2). That is, the first
At the stage where the stage polymerization is completed, a polymer A linked by a ketone peroxy group, or a polymer containing two or more peroxy groups resulting from a bimolecular recombination termination reaction of such growing radicals, or An active polymer A is obtained in which one of the two remains without being decomposed and a peroxy group and a hydroperoxy group remain at the terminals of the polymer. Monomer B is then added in the second stage without addition of any other catalyst. By raising the temperature of the system, the remaining peroxy groups are decomposed to generate radicals, and monomer B is added to form an AB block copolymer as shown in formula (4). According to the reaction mechanisms of formulas (1) to (4), homopolymers of A and B are not produced, but in reality, some homopolymers of both are observed to be produced. This is because in the first stage, an inactive polymer is formed due to the decomposition of a trace amount of ketone peroxy groups, and at the end of the first stage polymerization, the hydroperoxy groups are not completely decomposed and a trace amount remains. , due to the formation of inert polymers due to side reactions of some hydroxyl radicals,
In order to generate an inert polymer by a radical chain transfer reaction, and a part of the dihydroperoxy group of the catalyst is changed to a hydroxy group during synthesis or storage, 1-hydroperoxy, 1' Possible causes include -hydroxydicyclohexyl peroxide. However, these are small compared to the main reaction, and by appropriately selecting the type of reducing compound used and polymerization conditions, the production of homopolymers can be kept to an extremely low level. Furthermore, the block copolymer which is one component of the composition of the present invention is composed of monomer A used in the first step and monomer A used in the second step.
Even if the order of the monomers B used in the step is reversed, a BA type block copolymer can be obtained in the same manner. The operation is extremely simple, with monomers A and 2 in the first stage.
It is only necessary to replace the monomer B in the column. A peroxide (catalyst) generally called cyclohexanone peroxide is easily synthesized from cyclohexanone and hydrogen peroxide, but the resulting reaction product varies depending on the reaction conditions and additives, and to date, the following structure has been used: known to. The amount of active oxygen is (a) 12.12%, (b) 21.61%, (c) 6.95
%, (d) 12.99%, (e) 18.29%, (f) 14.02%, (g) 14.02
%. Catalysts that are effective in the synthesis of the block copolymer that is part of the composition of the present invention are dicyclohexanone peroxides having structures (d) and (e); others are only useful as catalysts for polymerization and curing. Therefore, it cannot be used for the purpose of the present invention. It has become industrially possible to selectively synthesize (d) and (e), and peroxide (d) is actually commercially available. The peroxide catalyst represented by (e), which is most convenient for the present invention, has a relatively high theoretical active oxygen content of 18.29%, and care must be taken when handling it when taking it out as a pure product. There will be no problem if the synthesis and handling are carried out inside. During synthesis, some
Although by-products of (c), (f), and (g) or changes to (d) may occur, the purpose can be achieved even if a trace amount of these compounds is contained. R in the above (a) to (g) is a hydrogen atom and a methyl group,
Representing an ethyl group, monoalkylbis substituents at the 2, 3, 4, 2', 3', 4' positions, 2-3, 2-
5, 3-4, 2'-3', 2'-5', dialkylbis substituents at the 3'-4' positions, 3, 3, 5, 2, 2,
5, represents a trialkylbis substituted product at the 3', 3', 5', or 2', 2', or 5' position. In the synthesis of the block copolymer, which is one component of the present invention, the reducing compound used in the first stage polymerization promotes only the radical decomposition of the hydroperoxy group of the catalyst and peroxy group (ketone peroxy group). ) are selected that either do not promote the decomposition of the compound at all or have only a slight effect on it. Typical examples of such compounds include sodium sulfite, sodium bisulfite, sodium thiosulfate, sodium dithionite, sodium formaldehyde sulfoxylate, L-ascorbic acid, and dextrose.
Compounds of iron and copper can also be used if the polymerization conditions are strictly regulated. These reducing agents may be used alone or in combination of two or more. In addition, it has been recognized that the emulsifier, auxiliary agent, system pH, and polymerization temperature used during polymerization affect redox polymerization. Until now, cyclohexanone peroxide has been used as a curing catalyst for highly unsaturated polyesters, and for example, as a reducing agent, it has been used as a reducing agent for amines such as dimethylaniline and dimethyl para-toluidine, and organometallic compounds such as cobalt naphthenate, nickel octylate, and ferrocene. It is a well-known technique to use it in combination with The reaction mechanism of these catalyst systems is that these amines and metal compounds act on both the hydroperoxy groups and ketone peroxy groups of the catalyst to radically decompose them. Such a method of use merely increases the polymerization curing activity of the catalyst at low temperatures, and even if such a system is employed, a block copolymer cannot be obtained. Therefore, strong reducing compounds and strong electron-donating compounds that also promote the decomposition of ketone peroxy groups cannot be used for the purpose of the present invention. As the polymerization method for providing the composition of the present invention, emulsion polymerization method and suspension polymerization method are employed. It is also possible to carry out the first stage polymerization by emulsion or suspension polymerization, and to carry out the second stage polymerization by bulk or solution polymerization, but this is not preferred because the steps are complicated and the cost is high. Furthermore, since the reducing compound used in the first stage polymerization is relatively difficult to dissolve in organic solvents and monomers, emulsion polymerization and suspension polymerization using water as a medium are suitable. 100 to 50% by weight of alkyl acrylate having 1 to 12 carbon atoms in the alkyl group of monomer or monomer mixture A
and a monomer having a CH ₂ =C group copolymerizable therewith from 0 to 50% by weight. Examples of such acrylates include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, and dodecyl acrylate, and one or more of these may be used. As a monomer having a CH ₂ =C〓 group,
Alkyl methacrylate, styrene, α-methylstyrene, nuclear substituted styrene, vinyl cyanide,
vinyl halides, vinyl esters, unsaturated acids,
Examples include vinyl ether and divinyl monomer. Monomer or monomer mixture B is copolymerizable with 100 to 50% by weight of alkyl methacrylate.
It is composed of 0 to 50% by weight of a monomer having a CH ₂ =C group. Alkyl methacrylate is an essential component that is compatible with PVC polymers, and methyl methacrylate is a typical example, and other examples include ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, and lauryl methacrylate. . As a monomer having a CH ₂ =C〓 group,
Alkyl acrylate, styrene, α-methylstyrene, nuclear substituted styrenes, vinyl cyanide,
Examples include vinyl halides and vinyl esters. The ratio of monomer (A) to monomer (B) is limited to 10 to 500 parts by weight of monomer (B) per 100 parts by weight of monomer (A). When monomer (B) is less than 10 parts by weight
Due to poor compatibility with the PVC polymer, a composition with good physical properties cannot be obtained, and if the amount exceeds 500 parts by weight, the yield of the block copolymer decreases, resulting in a composition with good physical properties. I can't get things. Next, an embodiment of the present invention will be described in more detail using an emulsion polymerization system as an example, in which a monomer or monomer mixture A is used in the first stage. First, in the first step, 0.1 to 5 parts by weight of dicyclohexanone peroxide having at least one hydroperoxy group is dissolved in 100 parts by weight of A, and water, an emulsifier, and if necessary a polymerization aid are added to a reaction vessel.
In addition to the polymerization system being purged with an inert gas such as nitrogen, the temperature of the system is adjusted to 0° to 60°C, preferably 20° to 50°C.
℃ and add the reducing compound. After the polymerization of A is completed, add B in the second stage to the system and heat the mixture at 50°~
Polymerization is carried out at 150°C, preferably between 60° and 90°C. The monomers in the first and second stages may be added all at once, added in portions, or added continuously. The second stage monomer is initiated by radicals generated by thermal decomposition of the residual peroxide bonded to the first stage polymer A, resulting in the production of a block copolymer. If the second stage polymerization is desired to be carried out at a low temperature, a small amount of a known decomposition aid that promotes the decomposition of ketone peroxy groups may be added, but the addition of such an aid may reduce the yield of the block copolymer. Care must be taken as this will reduce the rate. Additionally, a chain transfer agent may be added during the second stage polymerization for the purpose of controlling the molecular weight, but since this also reduces the yield of the block copolymer, it should be added in the latter half of the polymerization, especially at the final stage, if necessary. It is preferable. The polymer latex thus obtained is coagulated with an aqueous solution of acid, salt, etc., washed, dehydrated, and dried to form a powder. The composition of the present invention is obtained by mixing 0.3 to 70 parts by weight of this block copolymer with 99.7 to 30 parts by weight of the PVC polymer. In addition to polyvinyl chloride, the PVC polymer includes a copolymer of 70% by weight or more of vinyl chloride and 30% by weight or less of a monomer copolymerizable with it. The block copolymer and PVC polymer are mixed using a known kneading machine. Mixing rolls, calendar rolls, extruders, Banbury mixers, injection molding machines, etc., and before this mixing, a Henschel mixer,
Preliminary mixing can also be performed using a blender or the like. At this time, known stabilizers, lubricants, colorants, and fillers used in processing and molding PVC can also be added. The composition comprising 0.3 to 5 parts by weight of the block copolymer () and 99.7 to 95 parts by weight of PVC () of the present invention is significant as a composition that greatly increases the molding process range of PVC, and is effective in forming gelatinized PVC. While promoting this, the processability of secondary molding is greatly improved. Random copolymers and graft copolymers of acrylic esters and methacrylic esters have been known as processing aids for PVC, but the composition of the present invention is different from these known processing aids. Different and interesting physical properties have been recognized, and it is expected that interesting applications will be developed in the future. For example, with known processing aids, the higher the molecular weight, the poorer the dispersibility and the slower the gelation of PVC, but in this composition, the molecular weight of the block copolymer is increased. It shows good dispersibility and a good gelation promoting effect even when used. Block copolymer 5-30 parts by weight and PVC95-70
The composition consisting of parts by weight has remarkable characteristics as a composition having flexibility and excellent impact resistance, and is superior to compositions consisting of known acrylate-based elastomer copolymers or graft copolymers and PVC. also exhibits even better impact resistance. In this, 30 to 50 parts by weight of block copolymer and
Compositions containing 70 to 50 parts by weight of PVC also exhibit excellent sheet and film properties, with flexibility and good spreadability. In the following examples, parts and % mean parts by weight and % by weight, respectively. Example 1 5 parts of 1,1' dihydroperoxy, 1,1' dicyclohexyl peroxide (active oxygen content 17.7%)
It was dissolved in 600 parts of n-butyl acrylate.
Furthermore, dioctyl sodium sulfosuccinate is added to this.
2.5 parts were dissolved. Add 2,000 parts of distilled water to a stainless steel reaction vessel, purge thoroughly with nitrogen, add 0.4 parts of sodium pyrophosphate and 3 parts of sodium bisulfite, maintain the system temperature at 40 to 50°C, and remove n-butyl containing the catalyst. Acrylate was added continuously over 120 minutes and held for an additional 90 minutes to complete polymerization.
Next, 400 parts of methyl methacrylate was added, the temperature of the system was raised to 65-75°C, and the reaction was carried out for 180 minutes to obtain a uniform latex of block copolymer (B-1). This latex is coagulated with an aqueous aluminum sulfate solution, kept at 60°C to 90°C for 30 minutes to solidify, and then dehydrated, washed, and dried to produce a white powder polymer (B-
1) was obtained. This block copolymer and degree of polymerization
700 PVC was mixed using a Henschel mixer blend, and a film was formed using an extruder-T-die device to evaluate its physical properties. 2.5 parts of dibutyltin malate, 0.5 parts of dibutyltin mercaptide, 0.3 parts of butyl stearate as stabilizer and lubricant.
1 part, 0.2 parts of stearyl alcohol, and 0.3 parts of montan wax are added to 100 parts of PVC. Table 1 shows the physical properties of compositions obtained by varying the ratio of PVC/block copolymer. As a comparative example, a known catalyst, cumene hydroperoxide, was used instead of the above catalyst, and 0.5% of the monomer was used as the first and second stage polymerization catalysts, and 0.3% of sodium formaldehyde sulfoxylate was used as the reducing agent.
%, a polymer (C-1) of the same composition was obtained, and the measurement results obtained by mixing it with PVC in the same manner and evaluating it are also shown.

【table】

[Table] Example 2 5.5 parts of the catalyst used in Example 1 was dissolved in a monomer mixture consisting of 500 parts of methyl methacrylate, 60 parts of butyl methacrylate, and 40 parts of methyl acrylate, and 4 parts of sodium dioctyl sulfosuccinate were dissolved therein. . Add 2000 parts of deionized water to the reaction kettle,
After sufficiently purging with nitrogen, 1 part of sodium pyrophosphate and 3 parts of sodium formaldehyde sulfoxylate were added and maintained at 40 to 50°C, and the monomer mixture was added over 120 minutes and held for an additional 90 minutes.
Simultaneously with the addition of the monomer mixture, an aqueous solution of 1 part of sodium thiosulfate dissolved in 100 parts of distilled water was continuously added for 120 minutes. After completion of polymerization, add 300 parts of n-butyl acrylate and 100 parts of ethyl acrylate.
part, 1,3 butylene glycol dimethacrylate
The reaction system was brought to 65% by adding a monomer mixture consisting of 0.8 parts.
The reaction was completed by keeping at ~80°C for 150 minutes, and the powder block copolymer (B
-2) was obtained. 100 parts of PVC with a degree of polymerization of 1000, 30 parts of dioctyl phthalate, 2.5 parts of dibutyltin malate
1 part higher alcohol, 0.7 part Montan wax
The film properties were examined by adding the polymer (B-2) and the polymer (B-2). The results are shown in Table 2. In addition, as a comparative example, the composition and amount of monomers in the first and second stages were exactly the same, the polymerization catalyst was 0.4% potassium persulfate (based on monomer), and the polymerization temperature was 60°C.
The film properties when the polymer (C-2) obtained at the same temperature was used in the same manner were also investigated. Film formation was performed using an extruder-T die device. As is clear from Table 2, it can be seen that the composition of the present invention exhibits excellent film properties. As in this example, a block copolymer synthesized by using a monomer mainly composed of methacrylate in the first stage and a monomer mainly composed of acrylate in the second stage will produce an equally effective composition. You can get things.

【table】

[Table] Example 3 In a monomer mixture consisting of 600 parts of methyl methacrylate and 200 parts of isobutyl methacrylate, 6
1 part of dioctyl sodium sulfosuccinate is dissolved, and then 7 parts of 1-hydroperoxy 1'-hydroxydicyclohexyl peroxide are added and dissolved. Add 2,000 parts of deionized water to the reaction vessel, purify the system with nitrogen, and add 0.8 parts of sodium pyrophosphate.
1.5 parts of L-ascorbic acid, and 3 parts of sodium formaldehyde sulfoxylate were added, and the monomers were continuously added to the system maintained at 45 to 55°C over 180 minutes to complete the polymerization. Thereafter, 180 parts of n-butyl acrylate and 20 parts of acrylonitrile were added, and the temperature was raised to 70 to 80°C to complete polymerization.
The obtained polymer was processed to produce a white powder (B-3)
I got it. (B-3) 5 parts and PVC100 with a degree of polymerization of 1000
45 parts of dioctyl phthalate, 2.5 parts of cadmium-barium stabilizer, 2 parts of epoxidized soybean oil,
Add and mix 0.9 parts of higher alcohol and 3.0 parts of azobisdicarbonamide as a blowing agent, extrude at 145°C or below to form pellets, and use an extruder with a modified die.
When extruding at 155-160℃ and cutting the cross section of the foamed irregularly shaped rod to examine the uniformity of the foamed cells, we found that the conventional processing aid (Metablen P-551 manufactured by Mitsubishi Rayon)
It was observed that the uniformity of the foamed cells was better and the molding area was wider than when using 5 parts. In addition, a known catalyst (ammonium persulfate) was added to 0.4
When using the same amount of a polymer having the same composition and the same polymerization order as those obtained using the same percentage of monomer, the uniformity of the foamed cells was significantly inferior. Example 4 A monomer mixture consisting of 600 parts of n-butyl acrylate, 50 parts of 2-ethylhexyl acrylate, and 2 parts of ethylene glycol dimethacrylate was mixed with 3 parts of sodium dioctyl sulfosuccinate and the 1·1' dihydroperoxy used in Example 1. Add 5 parts dicyclohexyl peroxide to 1800 parts deionized water.
Add 0.6 parts of sodium pyrophosphate, 2 parts of sodium bisulfite, and 0.01 parts of ferrous sulfate, thoroughly purify with nitrogen, and add the monomers continuously over 120 minutes at 40 to 55°C. Polymerization was completed. Then 300 parts of methyl methacrylate, 50 parts of acrylonitrile
was added and kept at 65-75°C for 180 minutes to complete the polymerization. The obtained latex was treated to obtain a white powder (B-4). 100 parts of PVC with a degree of polymerization of 700, 3.5 parts of dibutyltin malate, 1.0 parts of butyl stearate
A test piece (90 mm x 15 mm, thickness 5 mm) was prepared by adding 0.5 parts of higher alcohol, 0.4 parts of montanic acid wax, kneading with a mixing roll at 165°C, and press-forming at 175°C - 100 kg/cm ² . When a 2mm V-notch was inserted and the shear peace impact strength was measured (B-
4) 10% content is 16.8Kg-cm/ ^cm2 , 15% content is 38.6Kg-cm/ ^cm2 , 20% content is 138Kg-
cm/ ^cm2 . On the other hand, it is obtained by a known graft polymerization method (the catalyst is cumene hydroperoxide-sodium formaldehyde sulfoxylate, 0.3% each).
Comparing the monomer) composition (C-4) under the same conditions, the 10% content was 7.2Kg-cm/cm2, and the 15% content was 7.2Kg-cm/ ^cm2 .
It was 9.1 Kg-cm/cm ² and 23.8 Kg-cm/cm ² with 20% content.

Claims (1)

[Claims] 1. General formula (In the formula, R ₁ and R ₂ are each hydrogen, methyl group or ethyl group, each cyclohexanone ring can have up to three alkyl groups (methyl group and/or ethyl group), and R' is hydrogen or As the first stage polymerization, a redox catalyst consisting of a peroxide (which is a hydroxyl group) and a reducing compound that promotes the decomposition of the hydroperoxy group of the peroxide but does not easily promote the decomposition of the ketone peroxy group is used. 100 to 50% by weight of at least one alkyl acrylate having an alkyl group having 1 to 12 carbon atoms and 0 vinyl and/or vinylidene compounds copolymerizable therewith.
~50% by weight of a monomer or monomer mixture (A)
100 parts by weight is polymerized, and then as a second stage polymerization, 100 to 50 weight % of an alkyl methacrylate having an alkyl group having 1 to 12 carbon atoms and 0 to 50 weight % of a vinyl and/or vinylidene compound copolymerizable therewith.
A block copolymer (B) obtained by polymerizing 10 to 500 parts by weight of a monomer or monomer mixture (B) consisting of ) and in the second stage polymerization, 0.3 to 50 parts by weight of a block copolymer (') obtained by polymerizing the monomer or monomer mixture (A), and 99.7 to 99.7 parts by weight of a vinyl chloride resin (). 50 parts by weight of a vinyl chloride resin composition.