JPH08157632A - Vinyl chloride resin composition for expansion molding - Google Patents

Abstract

PURPOSE: To obtain a vinyl chloride resin composition for expansion molding and suitable for the production of an expanded vinyl chloride resin article having high stiffness and surface hardness and giving an excellent surface free from tackiness. CONSTITUTION: This vinyl chloride resin composition for expansion molding use contains a vinyl chloride resin for paste molding, a plasticizer, a foaming agent and a styrene polymer, an A-B-type block copolymer or a mixture of a styrene polymer and the A-B-type block copolymer. The amount of the polymer or copolymer is 2-15 pts.wt. based on 100 pts.wt. of the vinyl chloride resin for paste molding. The A-B-type block copolymer is composed of a polymer block A containing styrene as a constituent unit and a polymer block B containing vinyl acetate or a (meth)acrylic acid ester as a constituent unit.

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 for foam molding used for producing foams such as wallpaper and ceiling materials. More specifically, the present invention relates to a vinyl chloride resin composition for foam molding, which is suitable for producing a foam having a good surface having high rigidity and high surface hardness without stickiness.

[0002]

2. Description of the Related Art This type of vinyl chloride resin composition comprises a vinyl chloride resin for paste processing (hereinafter abbreviated as paste vinyl chloride) containing a plasticizer, a filler, a foaming agent, a stabilizer and a pigment as main components, It is prepared by blending a diluent, a deodorant, a fungicide, a fragrance, etc., if necessary, and stirring and mixing them.

The vinyl chloride resin composition thus prepared is then applied to a substrate such as flameproof paper by a knife coater,
It is applied by a roll coater or the like and further printed by a gravure printing machine, a rotary screen printing machine or the like.
Then, the paste is melted and the foaming agent is decomposed, and the foamed body is molded by heating under a condition suitable for foaming. In the production of foam products, the foam is embossed or various patterns are printed prior to foaming. Further, if necessary, a matte treatment, a stain prevention treatment and the like are performed before and after the foaming process. The paste PVC foam product manufactured in this manner is widely used as a wallpaper or ceiling material as an interior decoration material having excellent design.

Various measures have been taken to improve the quality of the product, such as imparting a design property by diversifying multicolor printing, patterns and embossing, matting, deodorizing, antifungal, antibacterial, anticondensing, and stain prevention. It is intended to add functionality such as.

[0005]

However, the foam product obtained from the paste PVC has a problem that the product surface is easily scratched during construction or use because it has a low rigidity and a low surface hardness. Therefore, foam products that are strong and have high surface hardness have been desired. Further, since the foamed product is essentially a soft product, there is a problem that a sticky feeling remains on the surface, and a product having a good surface without sticky feeling has been desired.

[0006] As a composition satisfying such requirements, there is known a composition in which the compounding amount of a plasticizer is minimized. However, if the compounding amount of the plasticizer is reduced, the paste viscosity becomes high and the coatability deteriorates. Therefore, it is necessary to adjust the paste viscosity by using a large amount of diluent. This method has a problem that a large amount of the diluent is volatilized in the step of heating and foaming, which causes the foamed surface to be rough and the working environment to be deteriorated.

Further, in Japanese Patent Laid-Open No. 5-339413, a special plasticizer having a structure represented by the following chemical formula (1) is blended in an amount of 5 to 70% by weight based on the total amount of the plasticizer, whereby a foam product made of paste PVC is used. It is disclosed that the hardness of the sheet is high, the surface hardness is high, and the stickiness of the surface is reduced. However, no substantial improvement can be expected in the composition obtained by improving the plasticizer.

[0008]

Embedded image

(In the formula, R represents an alkylene group having 2 to 4 carbon atoms, X represents a linear or branched alkyl group having 1 to 10 carbon atoms, and n is an integer of 1 to 5.) As described above. In the past, it was difficult to obtain a foamed product having a good surface which is firm, has a high surface hardness, and is not sticky without deteriorating the workability and the working environment during the heat foaming process. .

The present invention has been made by paying attention to the problems of the prior art. An object of the invention is to provide a vinyl chloride resin composition for foam molding, which is suitable for producing a foam having a good surface which is firm and has a high surface hardness and is not sticky.

[0011]

In order to achieve the above object, in the invention of the vinyl chloride resin composition for foam molding according to claim 1, the styrene polymer is added to the paste vinyl chloride 10
2 to 15 parts by weight is contained with respect to 0 parts by weight.

According to the second aspect of the present invention, the polymer portion A having styrene as a constitutional unit and vinyl acetate or (meth) acrylic acid ester [in the present invention, acrylic and methacrylic are generically referred to as (meth) acrylic). 2 to 15 parts by weight of an AB block copolymer consisting of a polymer part B having a unit of
It is to contain by weight.

Further, according to the invention described in claim 3, a styrene polymer and a polymer portion A containing styrene as a constitutional unit.
2 to 15 parts by weight in total with respect to 100 parts by weight of the above paste vinyl chloride, and an AB type block copolymer comprising a polymer portion B having vinyl acetate or (meth) acrylic acid ester as a constitutional unit. It is a thing.

The present invention will be described in detail below. Examples of the paste vinyl chloride in the present invention include a vinyl chloride homopolymer, a vinyl chloride / vinyl acetate copolymer, a vinyl chloride / ethylene copolymer and the like, and one or more of these are used. Further, for the purpose of adjusting the sol viscosity of the vinyl chloride resin composition, increasing the amount of the vinyl chloride resin composition, or delustering the foam, an average particle diameter of 2
A vinyl chloride resin having a thickness of 0 to 50 μm can also be used in combination.

Examples of the plasticizer in the present invention include phthalate ester plasticizers such as dioctyl phthalate, dibutyl phthalate, diisononyl phthalate, butylbenzyl phthalate, dihexyl phthalate, and diisodecyl phthalate, as well as malonates. System plasticizers, succinic acid ester plasticizers, adipic acid ester plasticizers, sebacic acid ester plasticizers, epoxy plasticizers, polyester plasticizers, etc., and one or more selected from these Used.

If desired, a secondary plasticizer may be used in combination with the plasticizer. Examples of the secondary plasticizer include phosphite plasticizers, chlorinated paraffins, alkylbenzenes, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, and the like.

The blending amount of the plasticizer containing the secondary plasticizer is not particularly limited, but is preferably 30 to 100 parts by weight, more preferably 40 to 8 parts by weight with respect to 100 parts by weight of the paste vinyl chloride.
0 parts by weight. If the amount is less than 30 parts by weight, the flexibility required for the foam will be lost, and cracking will tend to occur during bending. On the other hand, when it exceeds 100 parts by weight, bleeding of the plasticizer occurs, and the foam surface tends to have a sticky feeling.

Next, as the foaming agent, for example, azo-based foaming agents such as azodicarbonamide, azobisformamide, azobisisobutyronitrile and diazoaminobenzene,
N, N-dimethyl-N, N'-dinitrosoterephthalamide, N, N'-dinitrosopentamethylenetetramine and other N-nitroso type foaming agents, benzosulfonyl hydrazide, toluene-4-sulfonyl hydrazide, benzene-
Examples include sulfonyl hydrazide-based foaming agents such as 1,3-disulfonyl hydrazide, 4,4′-oxybis (benzenesulfonyl hydrazide) and sulfone hydrazide, which are used for foam molding of vinyl chloride resin.
Azodicarbonamide is particularly preferable.

The blending amount of the foaming agent is not particularly limited, but it is preferably 2 to 10 parts by weight, more preferably 3 to 8 parts by weight with respect to 100 parts by weight of the paste vinyl chloride. If it is less than 2 parts by weight, a good foam having a sufficient expansion ratio cannot be obtained under ordinary foaming conditions, and if it exceeds 10 parts by weight, uniform foam cells cannot be obtained and the foamed surface is It tends to get rough.

Next, as the styrene-based polymer, a styrene-based copolymer such as a styrene homopolymer, a styrene / methyl methacrylate copolymer, a styrene / acrylonitrile copolymer or the like is used. This styrene polymer is
A polymer containing 50% by weight or more of styrene as a constitutional unit is preferably used, and two or more kinds can be used in combination.

The amount of the styrene polymer compounded is 2 to 15 parts by weight, preferably 4 parts by weight, based on 100 parts by weight of the paste vinyl chloride.
10 to 10 parts by weight. When the amount is less than 2 parts by weight, it is not possible to produce a vinyl chloride resin foam having a high rigidity and a high surface hardness from the obtained vinyl chloride resin composition for foam molding. On the other hand, when it exceeds 15 parts by weight, the paste viscosity of the obtained vinyl chloride resin composition for foam molding becomes high, the coatability is deteriorated, the flexibility of the foam is lost, and cracking occurs during bending. .

Further, instead of the styrene polymer,
By using an AB block copolymer composed of a polymer portion A having styrene as a constituent unit and a polymer portion B having vinyl acetate or a (meth) acrylic acid ester as a constituent unit, a vinyl chloride resin is obtained. The compatibility is improved, and a foam having a good surface without stickiness can be obtained. Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate. One or more of these may be used, with methyl methacrylate being most preferred.

In the AB block copolymer,
The weight ratio of the polymer portion A and the polymer portion B is not particularly limited, but is preferably 50/50 to 99/1, more preferably 70/30 to 95/5. When the ratio of the polymer portion A is less than 50/50, it is difficult to produce a vinyl chloride resin foam having high rigidity and high surface hardness from the vinyl chloride resin composition for foam molding. On the other hand, when the ratio of the polymer portion A exceeds 99/1, the compatibility between the AB type block copolymer and the vinyl chloride resin is slightly deteriorated and the bleeding of the AB type block copolymer on the surface is caused. Tend to occur, and the surface of the foam tends to be sticky.

The mixing amount of the AB block copolymer is 2 to 15 parts by weight, preferably 4 to 10 parts by weight, based on 100 parts by weight of the paste vinyl chloride. If the blending amount is less than 2 parts by weight, it is not possible to produce a vinyl chloride resin foam having good rigidity and high surface hardness from the vinyl chloride resin composition for foam molding. On the other hand, if the amount exceeds 15 parts by weight, the paste viscosity of the resulting vinyl chloride resin composition for foam molding becomes high, the coatability deteriorates, the flexibility of the foam is lost, and cracking occurs during bending. There is a tendency.

Further, in the styrene-based polymer, an AB type block copolymer comprising a polymer portion A having styrene as a constitutional unit and a polymer portion B having vinyl acetate or a (meth) acrylic acid ester as a constitutional unit is used. By using the polymer together, the compatibility with the vinyl chloride resin is improved, and a foam having a good surface without stickiness can be obtained.

When the AB type block copolymer is used in combination with the styrene polymer, the weight ratio of the polymer portion A to the polymer portion B in the AB type block copolymer is not particularly limited. It is preferably 1/99 to 99/1, more preferably 5/95 to 95/5. When the ratio of the polymer portion A is less than 1/99, the styrene polymer and A
The compatibility of the mixture with the -B type block copolymer with the vinyl chloride resin is slightly deteriorated, bleeding of both polymers to the surface is likely to occur, and the foam surface tends to be sticky. On the other hand, when the ratio of the polymer portion A exceeds 99/1, the ratio of the polymer portion B in the AB block copolymer becomes less than 1/99, and the block copolymer is changed to the styrene polymer. When used in combination, the proportion of the polymer portion B is further reduced from 1% by weight, so that the styrene polymer and A-
The compatibility of the mixture with the B-type block copolymer with the vinyl chloride resin is slightly deteriorated, the bleeding of both polymers to the surface is likely to occur, and the surface of the foam tends to be sticky.

The combined ratio of the styrene-based polymer and the AB type block copolymer is not particularly limited, but A in the total amount of the styrene-based polymer and the AB type block copolymer is used.
The proportion of the polymer portion B based on the -B type block copolymer is preferably determined to be 1 to 50% by weight. When the amount is less than 1% by weight, the compatibility of the mixture of the styrene polymer and the AB block copolymer with the vinyl chloride resin is slightly deteriorated, and the bleeding of both polymers on the surface easily occurs, and foaming occurs. The body surface tends to be sticky. On the other hand, when it exceeds 50% by weight, it tends to be difficult to produce a vinyl chloride resin foam having a high rigidity and a high surface hardness from the vinyl chloride resin composition for foam molding.

The total compounding amount of the styrene polymer and the AB block copolymer is 2 to 15 parts by weight, preferably 4 to 10 parts by weight, based on 100 parts by weight of the paste vinyl chloride. If the blending amount is less than 2 parts by weight, it is not possible to produce a vinyl chloride resin foam having good rigidity and high surface hardness from the vinyl chloride resin composition for foam molding. On the other hand, when it exceeds 15 parts by weight, the paste viscosity of the vinyl chloride resin composition for foam molding obtained from it becomes high,
In addition to the poor coatability, the foam loses flexibility and tends to crack during bending.

Next, the AB type block copolymer is manufactured by a known production process (for example, Japanese Patent Publication No. Sho 3) using a polymeric peroxide (for example, described in Japanese Patent Publication No. 60-3327) as a polymerization initiator. 60-332
No. 7, Japanese Patent Publication No. 63-30956). Further, as the polymerization method, any polymerization method such as a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method or a solution polymerization method is adopted, but the suspension polymerization method is most preferable industrially. Specifically, vinyl acetate or (meth) acrylic acid ester is polymerized in the first stage polymerization reaction to obtain a polymer having a peroxy bond in the molecule, and styrene is reacted in the second stage polymerization reaction. Done. Conversely, styrene may be polymerized in the first-stage polymerization reaction, and vinyl acetate or (meth) acrylic acid ester may be polymerized in the second-stage polymerization reaction.

In this case, the polymer having a peroxy bond in the molecule produced by the first-stage polymerization reaction can be taken out from the reaction system as an intermediate and used as a raw material for the next block copolymerization. May be subsequently subjected to block copolymerization without being taken out from the reaction system.

As the polymeric peroxide, various polymeric peroxides (for example, Japanese Patent Publication No. 60-3)
327), and one or more of them are used. The following chemical formula (2)
Are most preferable.

[0032]

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The amount of the polymeric peroxide used is preferably 0.1 to 10 parts by weight based on 100 parts by weight of vinyl acetate or (meth) acrylic acid ester or styrene. Further, the polymerization temperature is 40 to 80 ° C. for the first stage polymerization and 60 to 10 for the second stage polymerization.
It is preferable that the temperature is 0 ° C. and the polymerization temperature in the second-stage polymerization is higher than the polymerization temperature in the first-stage polymerization. The polymerization time is 1 to 3 hours in the first-stage polymerization and 3 to 3 in the second-stage polymerization.
It is preferably 10 hours.

A homopolymer of styrene and vinyl acetate or a (meth) acrylic acid ester is by-produced during the production of the AB block copolymer. However, according to the above-mentioned production method, since the ratio of the net AB block copolymer in the whole polymer, that is, the block ratio is as high as 80% or more, there is no particular need for purification and it can be used as it is. it can.
Therefore, in the AB block copolymer of the present invention, the polymer portion A having styrene as a constitutional unit has a styrene homopolymer as a by-product, vinyl acetate or (meth) acrylic acid ester as a constitutional unit. The polymer portion B to be contained may contain a vinyl acetate homopolymer or a (meth) acrylic acid ester homopolymer produced as a by-product, respectively.

The styrene-based polymer and the AB block copolymer may be blended directly when the vinyl chloride resin composition is prepared, or diluted with the above-mentioned plasticizer to prepare a diluted plasticizer. You may use for preparation of a vinyl chloride resin composition.

Next, in the vinyl chloride resin composition for foam molding according to the present invention, an appropriate amount of a filler, a stabilizer, a pigment or a diluent which is generally blended can be blended. Examples of the filler include heavy or light calcium carbonate, clay, magnesium carbonate, wood powder, aluminum hydroxide and the like. Examples of the stabilizer include fatty acid salts of alkaline earth metals or alkali metals such as barium stearate, calcium stearate, lead stearate and tin stearate. Examples of the pigment include titanium oxide and the like. Examples of the diluent include organic solvents such as mineral spirits and mineral terpenes that are difficult to swell pasty vinyl chloride and easily volatilize during the heating step. Furthermore, if necessary, an appropriate amount of perfume, deodorant, antifungal agent, antibacterial agent and the like can be added.

The method for producing a vinyl chloride resin foam from the vinyl chloride resin composition for foam molding according to the present invention is carried out according to general heating and foaming processing conditions which are mainly determined by a combination of a vinyl chloride paste, a foaming agent and a stabilizer. Be seen. Specifically, first, the vinyl chloride resin composition is applied to a base material such as flameproof paper to a predetermined thickness with a knife coater or a roll coater. Then, the vinyl chloride resin foam is manufactured by heating under conditions suitable for foaming processing by melting the paste vinyl chloride and decomposing the foaming agent, preferably at 180 to 230 ° C. for 30 to 90 seconds.

If the heating temperature is lower than 180 ° C., a good foam having a sufficient expansion ratio cannot be obtained. on the other hand,
When the heating temperature exceeds 230 ° C., uniform foam cells cannot be obtained and the foam surface tends to become rough. If the heating time is less than 30 seconds, a good foam having a sufficient expansion ratio cannot be obtained. On the other hand, heating time is 90
Beyond seconds, it wastes time and loses economy.

[0039]

EXAMPLES The present invention will be described more specifically below with reference to examples, examples and comparative examples. In these examples, parts and% represent parts by weight and% by weight, respectively, unless otherwise specified. The measurement and evaluation items in each example were performed according to the following methods. (1) Block ratio A part of the polymer obtained by the production of the AB block copolymer was extracted with a Soxhlet extractor for 24 hours using cyclohexane as an eluent. Then, when vinyl acetate was used as a monomer constituting the polymer part B, methanol was used as an eluent, and when methyl methacrylate was used, acetonitrile was used as an eluent for extraction for 24 hours.

The weight loss due to extraction with cyclohexane is polystyrene (abbreviated as PS hereinafter), the weight loss due to extraction with methanol or acetonitrile is polyvinyl acetate (abbreviated as PVAc hereinafter), and polymethylmethacrylate (abbreviated as PMMA hereinafter). ) And the extraction residue as the net content of the AB block copolymer. The ratio of the net AB block copolymer in the polymer was defined as the block rate. (2) Constitutive ratio of polymer portion A and polymer portion B in AB type block copolymer Nuclear magnetic using a part of the polymer obtained by the production of AB type block copolymer Resonance spectroscopy (NMR) was performed. Then, the area of the signal (chemical shift δ = about 6.4 to 7.1 ppm) corresponding to the benzene ring proton of styrene (hereinafter abbreviated as St), that is, the integrated value, and vinyl acetate (hereinafter abbreviated as VAc) Area of signal corresponding to methine proton (chemical shift δ = about 5.2 ppm), that is, integrated value, or methyl methacrylate (hereinafter referred to as MM
Signal corresponding to a methyl proton bonded to the α-position carbon (abbreviated as A) (chemical shift δ = about 1.0 ppm)
Area, that is, the ratio (molar ratio) to the integrated value is converted into a weight ratio.

Then, S in the AB block copolymer is
Polymer portion A having t as a constitutional unit and VAc or MMA
A constituent ratio with the polymer portion B having a constituent unit (hereinafter referred to as A /
Abbreviated as B). (3) VAc based on AB block copolymer in the total amount of St-based polymer and AB block copolymer
Alternatively, the proportion of the polymer portion having MMA as a constitutional unit is formed by the following formula to form VAc or MMA based on the AB block copolymer in the total amount of the St-based polymer and the AB block copolymer. Percentage of polymer portion as unit (hereinafter abbreviated as proportion of PVAc or PMMA portion)
I asked.

Percentage of PVAc or PMMA part (%)
= (A-B type block copolymer blending amount x polymer portion B)
Ratio) × 100 / (blending amount of St-based polymer + blending amount of AB type block copolymer) (4) Foaming ratio Various foaming with respect to thickness of various semi-gel-like sheets produced by the method described in Example 1. The thickness ratio of the body was taken as the expansion ratio. (5) Waist Using the various foams produced by the method described in Example 1, a strip having a length of 200 mm and a width of 25 mm was prepared, and a sag test was performed with the strip at the center in the length direction. The waist strength of the foam was evaluated based on the degree of sagging according to the following criteria.

1: Weak, 2: Weak, 3: Strong,
4: Strong (6) Surface hardness Various foams produced by the method described in Example 1 were used to perform a finger touch test, and the surface hardness of the foams was evaluated according to the following criteria.

1: Soft, 2: Slightly soft, 3: Slightly hard, 4: Hard (7) Feeling of stickiness Using various foams produced by the method described in Example 1, a finger touch test of their surface was conducted. The tackiness of the foam surface was evaluated according to the following criteria.

X: Sticky feeling, Δ: Slightly sticky feeling, ◯: No sticky feeling (8) Cracking property during bending Various foams produced by the method described in Example 1 were subjected to a bending test, and The presence or absence of cracks during bending was evaluated. [Production of AB Block Copolymer of the Present Invention] (Reference Example 1) 300 parts of water, partially saponified polyvinyl alcohol (Nippon Gosei) in a glass reactor equipped with a thermometer, a nitrogen introducing tube, a stirrer and a condenser. 15 parts of a 1% aqueous solution of Chemical Industry Co., Ltd., trade name: Gohsenol KH-17) and 15 parts of a 10% aqueous dispersion of hydroxyapatite (Nippon Chemical Industry Co., Ltd., trade name: Super Tight 10) are charged. It is. Next, 0.5 part of the polymeric peroxide represented by the chemical formula (2) (hereinafter abbreviated as P.PO) was dispersed in the aqueous solution at room temperature for 1 hour, and then VAc10 was added.
Part, and while introducing nitrogen into the reactor, under stirring 6
Polymerization (first stage polymerization) was carried out at 0 ° C. for 2 hours.

After that, the reactor was cooled to room temperature and St9 was added to the reactor.
After charging 0 part and performing impregnation for 1 hour at room temperature with stirring, nitrogen was introduced into the reactor while stirring at 80 ° C. for 8 hours.
Polymerization (second-stage polymerization) was performed for 30 minutes at 90 ° C. for a time. After cooling to room temperature, the obtained polymer was washed with 130 parts of 5% hydrochloric acid, subsequently with water, filtered off, and vacuum dried to obtain 94 parts of a white granular polymer. By using a part of the obtained polymer, the block ratio and A / B in the AB block copolymer were
I asked for B. The results are shown in Table 1. (Reference Examples 2 to 4) An AB block copolymer was produced in the same manner as in Reference Example 1 except that the charged amounts of P.PO, VAc and St were changed as shown in Table 1. A polymer of The block ratio and A / B in the AB block copolymer were determined using a part of the obtained polymer.
The results are shown in Table 1. Reference Example 5 An AB type block copolymer was produced in the same manner as in Reference Example 1 except that VAc was replaced with MMA to obtain a white granular polymer. By using a part of the obtained polymer, the block ratio and A in the AB type block copolymer are
/ B was calculated. The results are shown in Table 1. (Reference Examples 6 to 8) An AB block copolymer was produced in the same manner as in Reference Example 5 except that the amounts of P.PO, MMA and St were changed as shown in Table 1. A granular polymer was obtained. The block ratio and A / B in the AB block copolymer were determined using a part of the obtained polymer. The results are shown in Table 1.

[0047]

[Table 1]

[Preparation of Vinyl Chloride Resin Composition and Production of Foam] (Example 1) Various materials shown in Table 2 were weighed in a 500 cc polyethylene cup and lightly premixed until the contents began to become a sol. After that, homomixer (Tokushu Kika Co., T
A vinyl chloride resin composition was prepared by stirring at 3000 rpm for 5 minutes with a K homomixer). This vinyl chloride resin composition was applied on a flameproof paper with a roll coater to a thickness of 0.3 mm, and then with a tabletop type gear oven at 150 mm.
The vinyl chloride resin composition was solidified by heating at 30 ° C. for 30 seconds to form a semi-gel sheet. The semi-gelled sheet was subsequently heated in a gear oven at 200 ° C. for 60 seconds to produce a foam. The expansion ratio, waist, surface hardness, surface tackiness, and cracking property during bending of the obtained foam were examined. The results are shown in Table 3.

[0049]

[Table 2]

(Examples 2 and 3) In Example 1,
A vinyl chloride resin composition was prepared according to Example 1 except that the compounding amount of PS was changed as shown in Table 3 to produce a foam. In Example 2, heating at 190 ° C. for 70 seconds,
In Example 3, a foam was manufactured by heating at 220 ° C. for 50 seconds. The results are shown in Table 3. (Examples 4 to 9) In Example 1, the AB block copolymers obtained in Reference Examples 1 to 3 and Reference Examples 5 to 7 were used in place of PS as shown in Tables 3 and 4. Except that a vinyl chloride resin composition was prepared according to Example 1,
A foam was produced. The results are shown in Tables 3 and 4.

[0051]

[Table 3]

[0052]

[Table 4]

As shown in Tables 3 and 4, when the vinyl chloride resin composition contains PS (Examples 1 to 3),
When the vinyl chloride resin composition contains a block copolymer (Examples 4 to 9), the obtained foams have a strong elasticity,
The surface hardness is high, the stickiness is good, and there are no cracks when bent. (Examples 10 to 15) In Example 1, except that the AB block copolymers obtained in Reference Examples 1 to 8 were used in combination with PS as shown in Table 5, chloride was prepared according to Example 1. A vinyl resin composition was prepared to produce a foam. The results are shown in Table 5.

[0054]

[Table 5]

As shown in Table 5, when a predetermined amount of the block copolymer was contained in the vinyl chloride resin composition (Example 1
0 to 15), the produced foam has a strong elasticity, a high surface hardness, no sticky feeling, and no cracking during bending. Comparative Examples 1 to 4 In Example 1, PS and the AB block copolymers obtained in Reference Example 1 or 7 are shown in Table 6.
A vinyl chloride resin composition was prepared in the same manner as in Example 1 except that the composition was used as shown in Example 1 to produce a foam. The results are shown in Table 6.
It was shown to. (Comparative Example 5) In Example 1, the blending amount of the plasticizer was 25.
And a vinyl chloride resin composition was prepared according to Example 1 except that the St-based polymer and the AB block copolymer were not blended together, and the viscosity of the composition was very high. The coatability was very poor. Then, a foam was produced from the composition. The results are shown in Table 6. (Comparative Example 6) In Example 1, dioctyl phthalate and 2-butoxyethyl benzoate were used as plasticizers in 75/15.
Example 1 except that the St-based polymer and the AB block copolymer were not blended together, using a total of 50 parts at a ratio of%.
A vinyl chloride resin composition was prepared according to the above procedure to produce a foam. The results are shown in Table 6. This comparative example is disclosed in Japanese Patent Laid-Open No.
This is a supplementary test of Japanese Patent No. 339413.

[0056]

[Table 6]

As shown in Table 6, when the content of PS or block copolymer in the vinyl chloride resin composition is too small (Comparative Examples 1 and 4), the resin foams have a weak elasticity and surface hardness. Low. In addition, when the content of PS or the block copolymer is too large (Comparative Examples 2 and 3), cracking occurs during bending. Furthermore, when neither PS nor the block copolymer is used (Comparative Examples 5 and 6), the resin foams have a weak rigidity, the surface hardness is low, and cracks occur during bending.

Comparing the above examples with the comparative examples, by adding a specific amount of the St-based polymer to the vinyl chloride resin composition for foam molding comprising paste vinyl chloride, a plasticizer and a foaming agent, it is possible to obtain a good elasticity. It was found that a vinyl chloride resin composition for foam molding suitable for producing a vinyl chloride resin foam having high surface hardness can be obtained.

Furthermore, S is added to the vinyl chloride resin composition.
Polymer part A having t as a constitutional unit and polymer part B having VAc or (meth) acrylic acid ester as a constitutional unit
A vinyl chloride resin foam having good physical properties can also be produced by blending a specific amount of a mixture of an A-B type block copolymer or a St-based polymer and the AB type block copolymer. It has been found that a suitable vinyl chloride resin composition for foam molding can be obtained.

The technical ideas other than the claims will be described below along with their effects. (1) The proportion of the polymer part B based on the AB block copolymer in the total amount of the styrene polymer and the AB block copolymer is 1 to 50% by weight. The vinyl chloride resin composition for foam molding described in the above. According to this structure, it is possible to reliably obtain a vinyl chloride resin foam having a good surface which is strong and has a high surface hardness and is not sticky. (2) The vinyl chloride resin composition for foam molding according to claim 2, wherein the AB type block copolymer is mainly composed of a polymer portion A having styrene as a constitutional unit. If configured in this way, the obtained vinyl chloride resin foam will be stiffer,
The surface hardness can be increased. (3) The vinyl chloride resin composition for foam molding according to claim 2 or 3, wherein the AB block copolymer is obtained by a two-step polymerization using a polymeric peroxide. With this configuration, the block copolymer can be easily obtained with a high block ratio. (4) A method for producing a vinyl chloride resin foam, which comprises subjecting the vinyl chloride resin composition according to any one of claims 1 to 3 to heating and foaming.
According to this production method, it is possible to easily obtain a vinyl chloride resin foam having a good surface with high rigidity, high surface hardness and no sticky feeling.

[0061]

As described in detail above, according to the invention of the foam molding vinyl chloride resin composition of claims 1 to 3,
It is possible to obtain a vinyl chloride resin foam having a good elasticity, a high surface hardness, and a good surface without stickiness.

Claims (3)

[Claims] 1. A vinyl chloride resin composition for foam molding, which comprises a vinyl chloride resin for paste processing, a plasticizer and a foaming agent as constituents, and further comprises a styrene polymer with respect to 100 parts by weight of the vinyl chloride resin for paste processing. A vinyl chloride resin composition for foam molding containing 2 to 15 parts by weight. 2. A vinyl chloride resin composition for foam molding, comprising a vinyl chloride resin for paste processing, a plasticizer and a foaming agent as constituent components, further comprising a polymer portion A having styrene as a constituent unit and vinyl acetate or (meth). Vinyl chloride for foam molding containing 2 to 15 parts by weight of an AB block copolymer consisting of a polymer portion B having an acrylic ester as a constitutional unit with respect to 100 parts by weight of the vinyl chloride resin for paste processing. Resin composition. 3. A vinyl chloride resin composition for foam molding, comprising a vinyl chloride resin for paste processing, a plasticizer and a foaming agent as constituents, further comprising a styrene polymer and a polymer portion A having styrene as a constituent unit. AB comprising a polymer portion B having vinyl acetate or (meth) acrylic ester as a constitutional unit
A vinyl chloride resin composition for foam molding, which contains a mold block copolymer in a total amount of 2 to 15 parts by weight based on 100 parts by weight of the paste processing vinyl chloride resin.