JP2813248B2 - Vinyl chloride resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention comprises methyl methacrylate (component (a)) and a methacrylate ester having an alkyl group having 2 to 8 carbon atoms (component (b)). 80-40% (wt%, the same applies hereinafter), content of component (b)
The present invention relates to a vinyl chloride resin composition containing a processing aid for vinyl chloride resin comprising 20 to 60% of a copolymer. More specifically, a calender that gives an excellent gelation promoting effect at the time of molding without impairing the excellent physical properties and chemical properties inherent in vinyl chloride resins, and which could not be solved by conventional processing aids The present invention relates to a vinyl chloride-based resin composition obtained by adding and mixing a processing aid for a vinyl chloride-based resin, which simultaneously solves the generation of air marks and flow marks that are problematic during processing, to a vinyl chloride-based resin.

[0002]

2. Description of the Related Art Vinyl chloride resins are widely used in various fields because of their excellent physical and chemical properties. However, since the processing temperature is close to the thermal decomposition temperature, the temperature range in which molding can be performed is narrow, In addition, there are various processing problems such as a long time until the molten state. Many techniques are known that attempt to overcome these disadvantages. The outline is to add a plasticizer, copolymerize another monomer with vinyl chloride, and mix another resin-like substance with a vinyl chloride resin.

However, all of them have a drawback that the processability cannot be sufficiently improved while maintaining the excellent physical properties and chemical properties inherent in the vinyl chloride resin. For example, when a plasticizer is added or another monomer is copolymerized with vinyl chloride, the physical properties of a molded product are greatly changed. In addition, many of the materials in which other resin-like materials are mixed with the vinyl chloride resin are intended to lower the melt viscosity during molding and thereby lower the processing temperature, but these are apparently vinyl chloride. Although the flowability of the resin is improved, kneading energy is consumed by the flow, so that the gelation of the vinyl chloride resin ends insufficiently. Therefore, even if the product is apparently transparent, its physical properties are inferior to those of a sufficiently gelled vinyl chloride resin.

[0004] On the other hand, it promotes gelation during molding of vinyl chloride resin, improves secondary workability,
In addition, co-polymers containing methyl methacrylate as a main component are used for the purpose of improving workability, such as maintaining gloss on the surface of the molded product even during prolonged molding and smoothing the surface of the obtained molded product. A method of blending the coalesced as a processing aid has been proposed. These are all copolymers or copolymer mixtures consisting of methyl methacrylate and acrylate or methacrylic acid ethesyl except methyl methacrylate, but this is usually high in polymethyl methacrylate because of its softening temperature. This is because dispersion is not sufficiently performed under the processing conditions of the vinyl chloride resin, and an ungelled substance (fish eye) is left in a very large amount.

For example, Japanese Patent Publication No. Sho 53-2898 discloses a copolymer of methyl methacrylate and an acrylate ester of not more than 25 mol% in the total amount of the polymer. Are copolymers (I) comprising a superior amount of methyl methacrylate and an inferior amount of acrylate and / or methacrylic ester except methyl methacrylate, and an inferior amount of methyl methacrylate and A two-stage polymer consisting of a copolymer (II) consisting of acrylate and / or a predominant amount of methacrylate except methyl methacrylate,
And a copolymer mixture obtained by blending the copolymer (I) and the copolymer (II) in a latex state.

[0006] In any case of the above publications, copolymerization is carried out for the purpose of reducing the ungelled material.
A vinyl chloride-based resin composition containing a processing aid comprising such a specific copolymer has a high gelation rate during molding and an increased elongation at break at high temperatures. Subsequent workability can be greatly improved, so that not only deep drawing can be performed, but also vacuum forming, profile extrusion, and the like can be applied. The calendering also has the property of reducing air marks on the sheet. However, on the other hand, a vinyl chloride resin composition in which such a processing aid is blended with a vinyl chloride resin also has a drawback in that flow marks are generated on the sheet surface during calendering and the commercial value of the molded product is reduced. .

[0007]

In recent years, with the enlargement and high-speed production of calendering machines, the problem of the flow mark generated on the surface of the calendar sheet has become more important, and the flow mark has been reduced. There is an increasing demand for the development of technologies for obtaining high value sheets. The only drawback of conventional processing aids is the occurrence of this flow mark, which eliminates these drawbacks, and at the same time, the characteristics of conventional processing aids based on methyl methacrylate, namely the gelation of vinyl chloride resin. The development of a processing aid that promotes, improves the secondary workability of a molded article, and provides effects such as reducing air marks on a calendar sheet is of great industrial significance.

In order to solve the problem of the flow mark, when a methacrylic acid ester other than methyl methacrylate is used as a main component and the degree of polymerization is lowered, when it is blended with a vinyl chloride-based resin, it can be used in a molding process. A processing aid has been proposed which keeps the melt viscosity of the resin lower than that obtained by using a conventional processing aid (see Japanese Patent Application Laid-Open No. 1-247409). It has been shown that keeping the melt viscosity low improves the flow mark problem. The flow mark has been greatly improved by the use of such a processing aid, and keeping the melt viscosity at the time of molding processing low is certainly effective in improving the flow mark.

However, such a method improves flow marks in calendering, but at the same time sacrifices the favorable effects imparted by conventional processing aids, such as reducing air marks and improving secondary workability. . After all, the technique of keeping the melt viscosity low during the molding process is not an essential solution for improving the flow mark. That is, in the current technology, no processing aid has been obtained which simultaneously improves the flow mark, air mark, secondary workability, and the like in the calendar processing of the vinyl chloride resin to a sufficiently satisfactory level.

The present invention relates to a processing aid for improving a flow mark without sacrificing air marks, secondary workability, and the like.

[0011]

Means for Solving the Problems The present inventors have studied to solve the problem of the flow mark generated in the calendar processing of vinyl chloride resin without sacrificing the air mark, secondary workability, and the like. As a result, a specific amount of methyl methacrylate and a methacrylic acid ester having an alkyl group having 2 to 8 carbon atoms, and only a processing aid having a specific viscosity in a specific range are specific in solving this problem. In other words, by adding a specific amount of such a processing aid to the vinyl chloride resin, it promotes gelation that the conventional processing aid imparts to the vinyl chloride resin, improves secondary processing properties, and reduces air marks. It has been found that the effect of improving the processability such as the above can be obtained, and the problem of the flow mark in the calendering process is greatly improved.

That is, the present invention relates to a vinyl chloride resin
Parts (parts by weight, the same applies hereinafter) and a processing aid for vinyl chloride-based resin comprising 0.2 to 5 parts, wherein the processing aid for vinyl chloride-based resin is methyl methacrylate (a) 80 to 40.
%, 20 to 60% of a methacrylic acid ester having 2 to 8 carbon atoms in the alkyl group, and 2 to 0% of another type of monomer copolymerizable therewith, and having a specific viscosity ηsp (100 cm ³ (Dissolve 0.4 g of polymer in benzene and measure at 30 ° C) 0.8 to 2.0
The present invention relates to a vinyl chloride resin composition having good processability and physical properties in a calendering process, which is a vinyl chloride resin processing aid.

[0013]

The features of the present invention are, as described above, to promote gelation and improve secondary workability without impairing the excellent physical and chemical properties inherent in vinyl chloride resins. From the viewpoint of maintaining the characteristics of conventional processing aids such as reducing air marks in calendering and at the same time eliminating the problem of flow marks in calendering, the amount of acrylic acid ester conventionally used is reduced by 2%. % Or less, and only a copolymer having a specific range of specific viscosity and containing a specific range of methyl methacrylate and a methacrylic acid ester having 2 to 8 carbon atoms in an alkyl group as main components exhibits its effect specifically. That is the point that I found out.

The copolymerization of a methacrylic acid ester having 2 to 8 carbon atoms in the alkyl group is carried out for the purpose of preventing the formation of an ungelled product. In the prior art, as a means for preventing the generation of ungelled products of processing aids, copolymerization of methyl methacrylate with methacrylate esters other than acrylate or methyl methacrylate is carried out. If the purpose is to prevent the occurrence of acrylates and methacrylates other than methyl methacrylate, equivalent effects can be obtained by appropriately adjusting the content in the copolymer, and the object is achieved. . Therefore, in the prior art, there is no essential difference in the role played by methacrylates except acrylates and methyl methacrylate. In contrast, in the present invention Ru Tei clearly differentiate the properties of acrylic and methacrylic acid esters. That is, in order to maintain the advantages of the conventional processing aids and at the same time to solve the problem of the flow mark at the time of calendering, to obtain the effect of the present invention, the use amount of the acrylate is set to 2 % or less, Is a copolymer mainly composed of methyl methacrylate and a methacrylate having 2 to 8 carbon atoms.

The processing aid used in the present invention comprises 80 to 40%, preferably 70 to 50% of methyl methacrylate, and 20 to 60%, preferably 30 to 50% of a methacrylate having an alkyl group having 2 to 8 carbon atoms. 50% and 2 to 0% of other monomers copolymerizable therewith if necessary, and having a specific viscosity ηsp (1
Dissolve 0.4 g of polymer in 00 cm ³ of benzene and measure at 30 ° C)
Is a copolymer of 0.8 to 2.0.

[0016] The content of the methacrylic acid esters having a carbon number of 2 to 8 in the alkyl group of less than 20%, which would leave a lot of non-gelled in the molded body which had been kneaded with vinyl chloride resin. On the other hand, the content of methacrylate
If it exceeds 60% (for example, see Japanese Patent Publication No. 1-247409), if it is kneaded with a vinyl chloride resin, the secondary workability and transparency of the molded article will be reduced. When an acrylate is used in place of a methacrylate, the formation of ungelled substances is prevented, and the processing aid of the prior art has a sufficient kneading ability. The problem of the flow mark, which is an issue, cannot be solved.

When the specific viscosity ηsp of the processing aid is less than 0.8 , the flow mark is good, but a large number of air marks are generated.
In addition, there is a problem that the secondary workability of the molded body is reduced. Even if the amount of addition to the vinyl chloride resin is increased to improve this disadvantage, only the flow mark is deteriorated, and the air mark is improved. Can hardly be expected. on the other hand,
If the specific viscosity ηsp exceeds 2.0 , many flow marks will be generated, and if the amount added to the vinyl chloride resin is reduced to solve this drawback, the air mark will deteriorate, eventually satisfying both the flow mark and the air mark It cannot be improved to the extent possible (see Tables 1 and 2 below).

Examples of the methacrylate having 2 to 8 carbon atoms in the alkyl group include ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, benzyl methacrylate, and cyclohexyl methacrylate. Can be These may be used alone or in combination of two or more. Particularly preferred is n-butyl methacrylate.

The other monomer is used in an amount of 2 % or less in the processing aid so as not to impair the flow mark improving effect which is a characteristic of the processing aid of the present invention. Examples of such monomers include acrylates (eg, methyl acrylate, ethyl acrylate, n-butyl acrylate), unsaturated nitriles (eg, acrylonitrile, methacrylonitrile), and vinyl esters (eg, vinyl acetate, propionic acid). Vinyl, etc.). These may be used alone or in combination of two or more.

The processing aid used in the present invention can be obtained, for example, by subjecting the above-mentioned monomer to emulsion polymerization in the presence of an emulsifier, a chain transfer agent, a polymerization initiator and the like.

Known emulsifiers can be used, for example, anionic surfactants such as fatty acid salts, alkyl sulfate salts, alkyl benzene sulfonate salts, alkyl phosphate ester salts, sulfosuccinic acid diester salts, and the like. Nonionic surfactants such as oxyethylene alkyl ethers, polyoxyethylene fatty acid esters, and glycerin fatty acid esters, and cationic surfactants such as alkylamine salts can be used.

As the polymerization initiator, a water-soluble or oil-soluble polymerization initiator and a redox-based polymerization initiator can be used. For example, a common inorganic initiator such as a persulfate,
Or, an organic peroxide, an azo compound, or the like is used alone, or the compound and a sulfite, a hydrogen sulfite, a thiosulfate, a first metal salt, a sodium formaldehyde sulfoxylate, or the like are used in combination and used as a redox polymerization initiator. You can also. Preferred persulfates as initiators are sodium persulfate, potassium persulfate, ammonium persulfate, etc., and preferred organic peroxides are t-butyl hydroperoxide, cumene hydroperoxide,
Benzoyl peroxide, lauroyl peroxide and the like. The degree of polymerization is arbitrarily adjusted by combining a polymerization temperature, a chain transfer agent and the like in a usual manner.

The vinyl chloride resin used in the present invention is not particularly limited, and any conventionally used vinyl chloride resin can be used. Specific examples of such a vinyl chloride resin include, for example, polyvinyl chloride, preferably
Copolymers of 80% or more of vinyl chloride with monomers copolymerizable therewith (eg, vinyl acetate, propylene, styrene, acrylate, etc.), and post-chlorinated polyvinyl chloride. These may be used alone or in combination of two or more.

In the composition of the present invention, the ratio of the processing aid to the vinyl chloride resin is 100%.
Parts are from 0.2 to 5 parts, preferably from 0.5 to 3 parts, per part.
If the addition amount is less than 0.2 part, there is a problem in the air mark and the secondary workability of the molded article. If it exceeds 5 parts, the air mark is improved, but the flow mark problem occurs. .

The vinyl chloride resin composition of the present invention contains a stabilizer, a lubricant, an impact resistance enhancer, a plasticizer, a colorant, a filler,
A foaming agent or the like may be added.

As described above, the composition of the present invention is excellent in moldability and secondary workability, and retains the physical properties and chemical properties inherent in the vinyl chloride resin. It is suitably used in all fields used. In particular, it is possible to produce a molded product by calendering while significantly reducing the occurrence of flow marks without sacrificing air marks, secondary workability, and the like.

Hereinafter, the present invention will be described more specifically with reference to examples.

Example 1 In a reactor equipped with a stirrer, 2 parts of sodium dodecylbenzenesulfonate previously dissolved in water and 0.1 part of potassium persulfate were added.
And water was added to make the total amount of water 200 parts.
After the inside of the reactor was replaced with nitrogen to remove oxygen in the space and water, the content was heated to 70 ° C. while stirring. To this was added a monomer mixture consisting of 60 parts of methyl methacrylate and 40 parts of n-butyl methacrylate over 5 hours. After completion of the addition of the monomer mixture, stirring was continued for 1 hour and 30 minutes while maintaining the content at 70 ° C. to complete the polymerization, followed by cooling to obtain a polymer latex. The latex was salted out and coagulated with sodium chloride, filtered, washed with water and dried to obtain a powdery polymer sample. The specific viscosity ηsp of this polymer sample is 0.4 g / 100 cm ³
It was 1.2 when measured at 30 ° C. for the benzene solution.

3.0 parts of the obtained polymer sample (processing aid) were 100 parts of polyvinyl chloride (average degree of polymerization: 660), 100 parts of octyltin mercaptide stabilizer, epoxidized soybean oil
1.5 parts, 1 part of butyl stearate and 0.5 part of polyglycol ester of fatty acid were blended and subjected to the following test. Table 1 shows the results.

(I) Flow mark: kneading for 3 minutes at 200 ° C. and 20 rpm using an 8-inch roll to obtain a thickness of 0.5 mm
Was prepared, and the flow mark amount on the sheet was visually determined.

(Ii) Air mark: A sheet having a thickness of 2 mm was prepared under the same processing conditions as the flow mark, and the size and number of the air marks on the sheet were visually judged.

The flow mark and the air mark were evaluated by 良好, △, Δ, and × in a favorable order. Here ○
○ indicates that there is almost no flow mark or air mark, ○ indicates that the flow mark or air mark is very low, Δ indicates that the flow mark or air mark is conspicuous and seems to be a practical problem, The air mark is very prominent.

(Iii) Ungelled material: A sheet having a thickness of 0.3 mm is prepared under the same processing conditions as those for the flow mark, and the number of ungelled material (fish eyes) on the sheet is visually determined. , ○, △, Δ, ×. Where ○
は means no ungelled matter, 物 means almost no ungelled matter, △ means scattered ungelled matter and seems to be a practical problem, and × means many ungelled matters stand out.

(Iv) Transparency: After kneading with a roll at 170.degree. C. for 5 minutes and pressing at 180.degree. C. for 15 minutes, a plate having a thickness of 5 mm was used, and Nippon Denshoku Industries Co., Ltd. MEA
The total light transmittance (%) and scattered light (%) were measured by SURING SYSTEM.

(V) Tensile breaking elongation at 100 ° C .: As a measure of secondary workability, tensile breaking elongation at high temperatures was evaluated. The test piece was kneaded with a roll at 100 ° C for 5 minutes, then 180 ° C
Using a JIS No. 2 dumbbell prepared by pressing for 15 minutes at 100 ° C., the elongation at break was measured at 100 ° C. at a pulling speed of 200 mm / min.

Example 2 A polymer sample having a specific viscosity ηsp of 1.0 was obtained under the same conditions as in Example 1 except that the monomer mixture composition was changed to 45 parts of methyl methacrylate and 55 parts of ethyl methacrylate, and the same processing was evaluated. . Table 1 shows the results.

Example 3 A polymer sample having a specific viscosity ηsp of 1.0 was obtained under the same conditions as in Example 1 except that the composition of the monomer mixture was changed to 60 parts of methyl methacrylate and 40 parts of 2-ethylhexyl methacrylate. Done. Table 1 shows the results.

Example 4 A polymer sample having a specific viscosity ηsp of 1.0 under the same conditions as in Example 1 except that the composition of the monomer mixture was changed to 60 parts of methyl methacrylate, 38 parts of n-butyl methacrylate and 2 parts of n-butyl acrylate. And the same processing evaluation was performed. Table 1 shows the results.

Example 5 A polymer latex was prepared by adding 50 parts of methyl methacrylate over 2.5 hours to prepare a polymer latex in Example 1, and adding 25 parts of methyl methacrylate and 25 parts of methacrylic acid in the presence thereof. A two-stage copolymer latex was obtained in place of the method in which a monomer mixture consisting of 25 parts of n-butyl was added over 2.5 hours. This latex was treated in the same manner as in Example 1 to obtain a two-stage copolymer powder sample having a ηsp of 1.1, and the same processing evaluation was performed. Table 1 shows the results.

Comparative Example 1 A polymer sample having a specific viscosity ηsp of 1.1 was obtained under the same conditions as in Example 1 except that the monomer mixture composition was changed to 85 parts of methyl methacrylate and 15 parts of n-butyl methacrylate. Done. Table 1 shows the results.

Comparative Example 2 A polymer sample having a specific viscosity ηsp of 1.2 was obtained under the same conditions as in Example 1 except that the monomer mixture composition was changed to 30 parts of methyl methacrylate and 70 parts of n-butyl methacrylate. Done. Table 1 shows the results.

Comparative Example 3 A polymer sample having a specific viscosity ηsp of 1.0 under the same conditions as in Example 1 except that the monomer mixture composition was changed to 60 parts of methyl methacrylate, 30 parts of n-butyl methacrylate, and 10 parts of n-butyl acrylate. And the same processing evaluation was performed. Table 1 shows the results.

Comparative Example 4 A polymer sample having a specific viscosity ηsp of 1.0 was obtained under the same conditions as in Example 1 except that the monomer mixture composition was changed to 75 parts of methyl methacrylate and 25 parts of n-butyl acrylate. Done. Table 1 shows the results.

Comparative Example 5 A polymer sample having a specific viscosity ηsp of 1.0 was obtained under the same conditions as in Example 1 except that the monomer mixture composition was changed to 75 parts of methyl methacrylate and 25 parts of n-lauryl methacrylate. Done. Table 1 shows the results.

COMPARATIVE EXAMPLE 6 A polymer latex was prepared by adding 80 parts of methyl methacrylate in Example 1 over 4 hours to prepare a polymer latex, and adding 10 parts of methyl methacrylate and acrylic acid in the presence of the monomer. A two-stage copolymer latex was obtained in place of the method in which a monomer mixture consisting of 10 parts of n-butyl was added over 1 hour. This latex was treated in the same manner as in Example 1 to obtain a two-stage copolymer powder sample having a ηsp of 1.0, and the same processing was evaluated. Table 1 shows the results.

[0046]

[Table 1]

As shown in Table 1, the examples of the present invention have good evaluations of the gelled product, the flow mark and the air mark. The transparency and the elongation at break are also at the same level as those of the conventional processing aid. On the other hand, Comparative Example 1 has a large amount of ungelled matter because the amount of BMA copolymerized is small.
On the contrary, in Comparative Example 2, since the amount of BMA copolymerized was too large, the transparency was lowered. In Comparative Example 3, the flow mark and air mark were poorly evaluated because the amount of the acrylate was as large as 10 parts.
Comparative Examples 4 and 6 are one type of conventional processing aids composed of methyl methacrylate and an acrylate ester. However, as in Comparative Example 3, the evaluation of the flow mark and air mark was poor.
In Comparative Example 5, the flow mark and air mark evaluation was poor because the alkyl chain of the methacrylic acid ester used was too long.

Next, the flow mark, air mark, and the like were evaluated by changing the molecular weight or the amount of addition of the polymer sample (processing aid).

Example 6 The same operation was carried out except that the polymer sample obtained in Example 1 was added in an amount of 1.0 part per 100 parts of the vinyl chloride resin, and processed and evaluated. Table 2 shows the results.

Example 7 Polymerization was carried out in the same manner as in Example 1 except that the amount of the polymerization initiator was 0.04 part, and a polymer sample having a specific viscosity ηsp of 2.0 was obtained. Table 2 shows the results.

Comparative Example 7 The same operation was carried out except that the polymer sample obtained in Example 1 was added in an amount of 0.1 part per 100 parts of the vinyl chloride resin, and processing was evaluated. Table 2 shows the results.

Comparative Example 8 The same operation was carried out except that the polymer sample obtained in Example 1 was added in an amount of 8.0 parts per 100 parts of the vinyl chloride resin, and processed and evaluated. Table 2 shows the results.

Comparative Example 9 Polymerization was conducted in the same manner as in Example 1 except that the amount of the polymerization initiator was 0.01 part, and a polymer sample having a specific viscosity ηsp of 4.0 was obtained, and the same processing evaluation was carried out. Table 2 shows the results.

Comparative Example 10 The same operation was performed except that the polymer sample obtained in Comparative Example 9 was added in an amount of 1.0 part per 100 parts of the vinyl chloride resin, and processed. Table 2 shows the results.

Comparative Example 11 Polymerization was carried out in the same manner as in Example 1 except that 0.2 part of tertiary decyl mercaptan was added to the monomer mixture. A polymer sample having a specific viscosity ηsp of 0.3 was obtained, and the same evaluation was performed. Table 2 shows the results.

Comparative Example 12 The same operation was carried out except that the polymer sample obtained in Comparative Example 11 was added in an amount of 5.0 parts per 100 parts of the vinyl chloride resin, and processing was evaluated. Table 2 shows the results.

Comparative Example 13 A monomer latex was prepared in Example 1 by adding 80 parts of ethyl methacrylate, 10 parts of methyl methacrylate and 0.2 part of tertiarydecyl mercaptan over 4.5 hours. Then, a two-stage copolymer latex was obtained in place of the method of adding 10 parts of methyl methacrylate in the presence thereof over 0.5 hour. This latex was treated in the same manner as in Example 1 to obtain a two-stage copolymer powder sample having a ηsp of 0.3, and the same processing evaluation was performed. Table 2 shows the results
Shown in

[0058]

[Table 2]

As shown in Table 2, in Example 6, the amount of the polymer sample was set to 1.0 part by weight with respect to 100 parts of the vinyl chloride resin.
It can be seen that the parts also have good physical properties. Example 7 also shows that the polymer sample has good physical properties even when ηsp is 2.0. On the other hand, in Comparative Example 7, the evaluation of the air mark was poor because the number of blended parts of the polymer sample with the vinyl chloride resin was as small as 0.1 part. The evaluation of the flow mark is getting worse. Comparative Example 9 shows ηsp of a polymer sample.
Shows that the evaluation of the flow mark becomes poor when the value of the ま で is increased to 4.0.In Comparative Example 10, it was attempted to improve the flow mark by reducing the number of blending parts of the processing aid with respect to the vinyl chloride resin in which the ηsp was too high. In that case, the evaluation of the air mark will deteriorate, so the flow mark,
This indicates that it will not be a simultaneous improvement of the air mark.
In Comparative Examples 11 and 13, since ηsp was too low, the air mark,
Evaluation of the elongation at break is poor, and Comparative Example 12 shows that the physical properties are not improved even if the number of such processing aids added to the vinyl chloride resin is increased.

[0060]

Industrial Applicability The vinyl chloride resin composition of the present invention retains the excellent physical and chemical properties inherent in vinyl chloride resins, and has good gelling properties during molding. Furthermore, the secondary workability is good, and the occurrence of air marks and flow marks during calendering can be suppressed at the same time.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-74347 (JP, A) JP-A-1-247409 (JP, A) JP-A-60-223847 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) C08L 27/06 C08L 33/10

Claims (1)

(57) [Claims] 1. A composition comprising 100 parts by weight of a vinyl chloride-based resin and 0.2 to 5 parts by weight of a processing aid for a vinyl chloride-based resin, wherein the processing aid for a vinyl chloride-based resin is 80 to 40 methyl methacrylate. Weight% and the number of carbon atoms of the alkyl group is 2 to 8
Of methacrylic acid ester of 20 to 60% by weight and another monomer of 2 to 0% by weight copolymerizable therewith and having a specific viscosity of ηsp (0.4 g of a polymer dissolved in 100 cm ³ of benzene). ° C
A vinyl chloride resin composition having good processability and physical properties in a calendering process, which is a processing aid for vinyl chloride resins having a value of 0.8 to 2.0.