JPS5821433A - Vinyl chloride foamable resin composition - Google Patents

Abstract

PURPOSE:To prepare the titled resin composition capable of forming fine and uniform cells even by the atmospheric foaming method, and giving a foamed article having high expansion ratio and excellent rubber elasticity, heat resistance, and chemical resistance, by compounding an acrylic rubber and a crosslinking agent to a vinyl chloride resin. CONSTITUTION:The objective composition is prepared by compounding (A) 100pts.wt. of a vinyl chloride (co)polymer preferably having an average polymerization degree of 700-1,900, (B) 0.5-30pts.wt. of an acrylic rubber which is a copolymer composed of an alkyl acrylate as a main component and an active group (preferably epoxy group, or hydroxyl group) making a crosslinking point as a subsidiary component, (C) 0.1-5pts.wt. of a crosslinking agent which is a compound having two or more functional groups reactive with the active group of the component (B), (e.g. tolylene diisocyanate), (D) 1-20pts.wt. of a decomposing-type foaming agent, (E) 1-5pts.wt. of a stabilizer, and (F) 40- 180pts.wt. of a plasticizer. The modifying effect of the combined use of the components (B) and (C) is remarkable when the ratio of expansion is as high as >=7.

Description

DETAILED DESCRIPTION OF THE INVENTION Relating to eyelids. More specifically, the present invention has a vinyl chloride polymer or a vinyl chloride copolymer as the main component, and the cell structure of the foam is dense and uniform even when foamed at normal pressure using a calendar, etc., and even when foamed at a high ratio. Regarding a polyvinyl chloride foamable resin composition that has closed cells with excellent compression recovery properties and provides a foam with excellent rubber elasticity, heat resistance, chemical resistance, etc.〇 Manufacture of vinyl chloride resin foam Normal pressure foaming method or pressure foaming method is usually adopted as the foaming method.

In the normal pressure foaming method, a vinyl chloride foamable resin composition is usually molded at a temperature lower than the temperature at which the blowing agent decomposes, and then
A method is used in which the foaming agent is heated to a temperature higher than the decomposition temperature of the foaming agent, and the foam generated by the decomposition of the foaming agent causes foaming. On the other hand, in the pressure foaming method, the vinyl chloride foam resin composition is heated under pressure to a temperature higher than the decomposition temperature of the blowing agent to melt it, and the gas generated when the blowing agent decomposes is finely dispersed into the resin. A method is used in which the material is dispersed, then returned to normal pressure and foamed.

In normal pressure foaming of vinyl chloride-based foamable resin compositions, continuous molding is possible using calendar rolls or extruders; ), there are technical difficulties in that the cells in the resin become unevenly coarsened and even collapse, making it impossible to obtain the desired foam. The reality is that only foams with a certain expansion ratio can be obtained. In addition, the thick 7 ohm (10 V'm thickness 7 ohm) produced by normal pressure foaming remains distorted when compressed, and is not comparable to polyurethane foam or polyolefin 7 ohm in terms of cushioning properties.

On the other hand, in pressure foaming of a vinyl chloride foamable resin composition, a foam with rubber elasticity and a density of 0.03 to 0.15 g/am3 and an extremely high expansion ratio can be obtained, but as a foam, The heat resistance and chemical resistance expected of polyvinyl chloride are extremely low.

In order to solve the above-mentioned drawbacks in normal pressure foaming and processing foaming of vinyl chloride-based polymers, crosslinking agents, blowing agents, and plasticizers are added to vinyl chloride/I/based copolymers that have active hydrogen such as hydroxyl groups or carboxyl groups. A method has been proposed in which a foam is manufactured by blending a foaming agent with a foaming agent, but this method requires precise control of foam molding conditions, in which active hydrogen (i.e., hydroxyl or carboxyl The reaction between the crosslinking agent and the vinyl chloride copolymer containing hydrogen (such as On the other hand, when crosslinking precedes foaming, foaming is inhibited, and it has therefore been found that it is extremely difficult to scale a foam with uniform and fine cells and a high expansion ratio.

The present inventors have eliminated the above-mentioned drawbacks, and have improved rubber elasticity, heat resistance,
As a result of extensive research in order to provide a vinyl chloride resin foam with excellent chemical resistance and high expansion ratio, (4) 100 parts (parts by weight, the same applies hereinafter) of vinyl chloride polymer or copolymer. B) 0.5 to 60 parts of acrylic rubber and (0
) When a vinyl chloride foamable resin composition comprising 0.1 to 5 parts of a crosslinking agent, a blowing agent, a stabilizer and a plasticizer is used to produce a foam with a high expansion ratio, ordinary vinyl chloride polymers or copolymer It completely eliminates the disadvantage of conventional methods using coalescence, where cells (bubbles) in the foam become uneven, coarse, or collapse, resulting in only a foam with a low expansion ratio being obtained. We discovered a new fact that a foam with fine and uniform cells, excellent rubber elasticity, heat resistance, and chemical resistance, and a high expansion ratio can be obtained.
This led to the completion of the present invention.

The component (A) used in the present invention, that is, the vinyl chloride polymer or copolymer, is a vinyl monomer that can be copolymerized with vinyl chloride heptamer alone or with vinyl chloride hetamine! −
It includes all vinyl chloride polymers and vinyl chloride copolymers that can be obtained by ordinary suspension polymerization, emulsion polymerization, or other known polymerization methods. Examples of the vinyl yarn yarn copolymerized with vinyl chloride monomers include vinyl esters (e.g., vinyl acetate, vinyl propionate, vinyl stearate, etc.), olefins (e.g., ethylene, propylene, butylene, styrene, etc.), vinyl ethers (e.g., ethylene, propylene, butylene, styrene, etc.), (e.g. stearin vinyl ether, vinyl methyl ether, 3-hydroxybutyl vinyl ether, etc.), acrylic acid or methacrylic acid, or derivatives thereof (e.g. ethyl acrylate, ethyl methacrylate, 2-hydroxyethyl acrylate, 2- and droxyethyl methacrylate, 2-
hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, 3-hydroxybutyl acrylate, etc.), acrylamide or its derivatives (e.g. N-methylol acrylamide, N-butoxymethyl acrylamide, etc.), vinyl carboxylic acids (e.g. undecylenic acid, etc.), maleic acid or 7! vinylic acid, or their derivatives (e.g., motuptil maleate, diethyl 7-maleate in ethyl-2-hydrogen, etc.), and one or more of these vinyl monomers can be used together with the agglomerated vinyl monomer. Polymerized.

Copolymers obtained by further chemical treatment of vinyl chloride copolymers, such as terpolymers obtained by partially saponifying a coprimer of vinyl chloride and vinyl acetate, can also be suitably used.

Furthermore, one or two of vinyl chloride polymers or copolymers
A mixture of more than one species may also be used.

These vinyl chloride polymers or copolymers can be used with an average degree of polymerization in the range of 600 to 6,000, but from the viewpoint of workability, it is preferably in the range of 700 to 190G. When the average degree of polymerization is greater than 3,000, high temperature or long-term cross-contact is performed, and when the average degree of polymerization is less than 600, a sufficiently high expansion ratio and rubber elasticity cannot be obtained, and both are unfavorable.

In the present invention, the component (B), that is, the acrylic rubber, is an elastic body containing an acrylic acid alkyl ester as a main component, and is a copolymer with a subcomponent having an active group that serves as a crosslinking point. For example, ethyl acrylate, propyl acrylate, butyl acrylate,
acrylic! The main component is one or more of acrylic acid alkyl esters such as 2-ethylhexyl, including glycidyl ether, glycidyl acrylate, glycidyl methacrylate, toda xyethyl acrylate, hydroxyethyl methacrylate, and 2-chloroethyl vinyl ether. Examples include copolymers with subcomponents having an active group as a crosslinking point, such as, among others, acrylic rubber having a nigex group or a hydroxyl group as an active group is preferably employed.

Acrylic rubber is generally produced by salting out and drying an emulsion polymer obtained by an emulsion polymerization method, and is usually obtained in bulk form, but it can also be produced by a suspension polymerization method. Acrylic rubber is a general-purpose diolefin-based synthetic rubber J%, which has good compatibility with vinyl chloride-based resins and excellent heat resistance. Even when added in a small amount of about 1 part to 100 parts of vinyl chloride resin, it promotes gelation of the vinyl chloride resin and also exhibits the effect of controlling the air bubbles in the foam, making it extremely convenient as a processing aid.

The blending ratio of the acrylic rubber is 0.5 to 100 parts per 100 parts of the above-mentioned component (1) to impart excellent crosslinking properties to the resulting resin composition and to obtain a foam with excellent rubber elasticity.
60 parts (preferably 1 to 15 parts) If the blending ratio of acrylic rubber is less than the above range, the rubber elasticity of the foam, especially when foamed at a high magnification, will be poor, and if the proportion is greater than the above range. In this case, it is possible to use a foam with good rubber elasticity, but it is uneconomical because it requires a large amount of expensive acrylic rubber, and it also impairs the roll processability, which is an advantage of vinyl chloride resin. It's also undesirable.

However, in the present invention, only 1 to 5 acrylic rubbers are used.
Even though it is used in extremely small amounts of 1.5 parts, it can exhibit excellent crosslinking properties and rubber elasticity, and, as mentioned above, it also has the advantage of being able to improve the processability of vinyl chloride resins. The industrial value is enormous.

The above-mentioned component (0), that is, the crosslinking agent, used in the present invention includes compounds having two or more functional groups in the molecule that react with the active groups of acrylic rubber, such as isocyanate groups, blocked isocyanate groups, and carboxyl groups in the molecule. Compounds and dibasic acid anhydrides having a hydroxyl group, a nigex group, an alkoxyalkylamino group, a dorxyalkylamino group, an amino group, an alkyl mono- or di-substituted amino group, and the like are used. Typical examples thereof include tolylene diisocyanate, diphenylmethane diisocyanate, polyethylene phenyl isocyanate, or compounds having at least bifunctional active hydrogen in combination with the polyisocyanate (for example, trimethylolpropane, pentaerythritol, glycerin, polyethylene glycol, polytetramethylene glycol, polyethylene adipate, etc.) and an initial addition polymer having an isocyanate group at the molecular end; Acetoxime, acidic sodium sulfite, and more! Blocked isocyanates blocked with blocking agents, succinic acid, glutaric acid, adipic acid, 7-thalic acid, phthalic anhydride, cyclohexanedicarboxylic anhydride, triglycidyl isocyanurate, epoxy resin, triethylenetetramine, methylolmelamine, butoxy Examples include methylmelamine, and blocked isocyanates are particularly preferred.

The amount of these crosslinking agents used varies depending on the type of crosslinking agent used and the resin composition, but is in the range of 0.1 to 5 parts, preferably 0.3 to 4 parts, per 100 parts of the ((trans)component). When the amount of crosslinking agent used is more than 5 parts, it is economically disadvantageous and the effect of improving foamability and elasticity is small. When the amount is less, the cells tend to become rough due to insufficient crosslinking, and the rubber elasticity is poor, making it impossible to obtain a product with good recovery properties and feel, which are both unfavorable.

As the blowing agent used in the present invention, ordinary decomposition type blowing agents can be used as appropriate without any restrictions, and
Examples include azodicarbonyl hydrazide, p+p'-oxybisbenzenesulfonyl hydrazide, p-toluenesulfonyl hydrazide, and benzenesulfonyl hydrazide, which may be used alone or in combination of two or more. In particular, azodicarbonamide is preferably used. The amount of blowing agent used is (A) component 1
A range of 1 to 20 parts, preferably 2 to 15 parts per 0.00 parts is adopted, thereby producing a foam with a dense cell structure, uniform foamability, and excellent feel, and a foaming ratio of about 2 to 20 times. It will be done.

The modification effect of the foam using the above-mentioned (B) component and (0) component in the present invention is particularly noticeable in high-expansion foams with a foaming ratio of 7 times or more. Even when either component (B) or component (0) added as a modifier to component ) is missing, or when either of these components is out of the above range, the foam seen will have a cellular structure. It is not possible to significantly improve uniform density, compression recovery, rebound resilience, heat resistance, and chemical resistance.

Although the reason for this is not clear, components (II) and (0) are uniformly dispersed and mixed together with other ingredients in component (4), and this ( Because components B) and (0) are partially crosslinked, the viscosity of the resin composition becomes slightly higher during foaming at high temperatures compared to normal non-crosslinked products, and the superior properties of acrylic rubber Uniform partial crosslinking progresses due to stretchability and miscibility, and the cell film becomes tougher. Even when made into a high-magnification foam, the cells remain closed and uniformly dense. It is thought that a foam with rubber-like compression recovery properties, rebound resilience, and excellent heat resistance and chemical resistance can be obtained.

Stabilizers used in the present invention include, for example, metal compounds such as zinc, cadmium, barium, sodium, potassium, calcium, lithium, and tin, compound stabilizers thereof, and organic stabilizers such as oxidized compounds. Component (4): 1 to 5 parts, preferably 2 to S parts, per 100J3 parts. When the amount of the stabilizer used is less than 1 part, the vinyl chloride copolymer is likely to be deteriorated by heat, and when it is used in excess of 5 parts, it is uneconomical and undesirable.

Examples of the plasticizer used in the present invention include dioctyl 7
7-talate diethyl nitrates such as dibutyl phthalate and dinonyl phthalate, aliphatic dibasic acid esters such as dioctyl adipate and dioctyl sebacate, phosphoric triesters such as tricresyl phos-7ace and trioctyl phosphate, epoxidized soybean oil, etc. ester plasticizers such as polyester plasticizers, polyethylene adipate, diallyl phthalate, ethylene glycol dimethacrylate), 1,3-butylene gelicol diacrylate, trimethylolpropane trimethacrylate, etc. One type or a mixture of two or more types of flame retardant plasticizers such as reactive plasticizers, triβ-tri-WW ethylphos 7A), and chlorinated paraffins can be used.

The amount of these plasticizers used is 40 to 100 parts of the plasticizer component.
180 parts, preferably in the range of 50 to 150 parts. If the amount of plasticizer used is outside the above range, a foam with uniform cellization and a high expansion ratio can be obtained, but the rubber elasticity will decrease. This is a trend and is not desirable.

In the method of the present invention, a foamable resin composition prepared by blending a specific crosslinking agent, a commonly used blowing agent, a stabilizer, and a plasticizer with a specific resin composition is heated and foamed. Depending on the purpose, the product may contain other coloring agents such as organic dyes, organic pigments, and inorganic pigments, fillers such as calcium carbonate, aluminum hydroxide, clay, and talc, as well as powder type chlorinated paraffin,
A combustible agent such as antimony trioxide may be added as appropriate.

The following methods are usually employed to carry out the method of the present invention, but it goes without saying that other methods may also be employed.

11) The specific resin component, crosslinking agent, stabilizer, plasticizer, and other additives are mixed using a ribbon blender, pickler, Henschel mixer, etc., kneaded using a mill rule or Banbury mixer, and calendered. - The blowing agent is supplied to a mold or an extruder to form a sheet at a temperature below the decomposition temperature of the blowing agent, and then heated at a temperature of about 180 to 251) for about IIo seconds to 4 minutes to decompose the blowing agent and form a foam. do.

(2) Mix the specific resin component, crosslinking agent, stabilizer, plasticizer, and other additives in the same manner as in (1) above, and use a mill roll, Banbury mixer 1 extruder, etc. to reach the decomposition temperature of the blowing agent. After kneading at the following temperature, fill the mold at a ratio of 70 to 100% of the mold capacity, apply external pressure to the mold that can withstand the decomposition pressure of the blowing agent, and heat at a temperature of about 160 to 20,000 °C for 5 to 60 minutes. and decompose the blowing agent. The resin composition is then cooled to 20 to 60 degrees under external pressure, taken out from the mold, and expanded in a heating furnace heated to 90 to 150°C to form a foam.

+31 Component (B), that is, acrylic rubber, is dissolved in an organic solvent such as xylene, toluene, or benzene, a vinyl chloride plasticizer such as dioctyl phthalate or dibutyl phthalate, or Puma-7 oil for rubber, and then dissolved in other specified The resin components, cross-linking agents, stabilizers, plasticizers, and other additives are mixed using a ribbon mixer, pickling machine, Henschel mixer, etc., and then evenly mixed using a paint mill, homogenizer, etc. to produce release paper and flame retardant wallpaper. Apply to the desired thickness on a base material such as paper or woven fabric using a knife coater or roll coater, and apply at a temperature of 12°C at which the blowing agent does not decompose.
It is heated for 50 seconds to 6 minutes at a temperature of 0 to 160 degrees 0 to form a gel, and then heated at a temperature of about 180 to 250 degrees for 30 seconds to 4 minutes to decompose the foaming agent and form a foam.

As described above, in the method of the present invention, the problems in conventional normal pressure foaming of vinyl chloride foam resin compositions are completely solved, and even at a foaming ratio of 10 times or more, the cells are uniform and fine. It is possible to easily and reliably produce foams with high expansion ratios that have good rubber elasticity and excellent heat resistance and chemical resistance, and also have no residual distortion due to compression even when foamed under pressure. Improves elasticity. It is possible to produce a foam with excellent heat resistance and chemical resistance and a high expansion ratio, making it extremely useful industrially.

The resulting foam has rubber elasticity, heat resistance, and chemical resistance that cannot be obtained with ordinary vinyl chloride foam, making it ideal for use as cushioning materials, cushioning materials, flotation materials, and insulation materials. In addition, it can be applied to very good applications such as foamed leather for bags, clothing, and furniture without requiring high-density foaming, and its industrial value is extremely high.

Next, the resin composition of the present invention will be explained with reference to Examples and Comparative Examples, but it goes without saying that the present invention is not limited to these Examples.

The measurement and evaluation methods for the expansion ratio, cellular II% compression recovery, heat resistance, and chemical resistance in the following Examples and Comparative Examples are as follows.〇(1) Expansion ratio In the case of pressurized foam block shape (21 cell state ○: cell diameter is Q, uniform within 3 mm Δ: cell diameter is Q
, some with a diameter of 15 mm or more mixed, slightly uneven ×: Cell roughness is noticeable (many with a cell diameter of 1 mm or more)
The central part of the non-uniform (3) compression recovery foam was compressed with fingers about 90 times, and the recovery state after the pressure was removed was evaluated.

O: Immediate recovery after depressurization, and no traces of compression remained.

Δ: After the pressure was removed, traces of compression remained, but recovered within 10 seconds.

×: After the pressure was removed, traces of compression remained and did not recover even after 10 seconds had passed.

(4) The heat-resistant foam was cut into 5 cm square pieces, and changes in shape were examined after leaving them in the open at 200'0 for 5 minutes.

O: Almost no change in shape was observed.

Δ: The shape was slightly distorted.

×: The shape was completely destroyed.

(5) Chemical resistance! Place the foam of X3 om square in a 200 mA beaker,
0.1 liter of tetrahydro7ran was poured into the solution, and the state of dissolution of the foam was observed while shaking gently.

○: No dissolution was observed even after 30 minutes, and almost no change in shape was observed.

Δ: It did not dissolve even after 10 minutes had passed, but the shape was distorted.

×: Completely dissolved in the glass for 10 minutes.

Examples 1 to 5 and Comparative Example 1 The resin components and additives shown in Table 1 were kneaded for 7 minutes at 145% using two rolls to obtain each foamable resin sheet with a thickness of 0.7wn.

Place these sheets in the oven at 220°0 for 2-3 minutes.
It was heated and foamed for a minute.

The foaming ratio, cell state/compression recovery, heat resistance, and chemical resistance of each foam sheet obtained were examined. The results are shown in Table 1.

(Poured vinyl chloride homopolymer product (II! Shoulder polymerization, average degree of polymerization 1050) (Note 1 Acrylic rubber containing water-based groups (Tisan Rubber #5001 manufactured by Teikoku Kagaku Sangyo ■) (Note 5)) Diisocyanate adduct (Note 4) Ba-Kn system From the results in Table 1, it was found that the ordinary foamable resin composition (Comparative Example 1)
) The foam obtained in Examples 1 to 2 had a foaming ratio of 7.6 times under the above foaming conditions (heated at 22Goo for 2 minutes), and had significant cell roughness and poor compression recovery properties. In No. 5, the foaming ratio was increased to 10 by blending 1 to 60 parts of acrylic rubber and 4 parts of a crosslinking agent.
Even when it was doubled, the cell state remained dense and uniform, and it had excellent compression recovery properties, heat resistance, and chemical resistance.

Examples 6 to 11 and Comparative Example 2 The resin components and additives shown in Table 2 were kneaded and formed into a sheet in the same manner as in Examples 1 to 5, and heated for 2 minutes 60 seconds to 3 minutes in an open atmosphere at 220@O. The mixture was foamed.

The expansion ratio and physical properties of each foam are shown in Table 2.0 (Note 1) Vinyl chloride-vinyl acetate copolymer (suspension polymer, average degree of polymerization 700) -Hydroxypropyl acrylate copolymer (suspension polymer, average degree of polymerization 1200.2-
Hydroxypropyl acrylate content: 2.0 mol%
) (Note 6) Hydroxyl group-containing acrylic rubber (Tissan rubber 001 mentioned above) (Note 4) 4,4'-diphenylmethane diisocyanate (Note 5) Oa = Zn system From the results in Table 2, the blending effect of acrylic rubber is 0. You can see what can already be seen from part 5. When acrylic rubber is not added (Comparative Example 2), both the S cell shape and the compression recovery properties are sufficiently satisfied, and the foam cannot be stretched.

Examples 12 to 18 and Comparative Example 3 The resin components and additives shown in Table 6 were added to Examples 1 to 5.
The mixture was mixed and formed into a sheet in the same manner as above, and heated in an oven at 220°O for 2 minutes and 60 seconds to 3 minutes to foam.

Table 6 shows the expansion ratio and physical properties of each foam.

(Note 1) Vinyl chloride homopolymer (suspension polymer, average degree of polymerization 1550) (Note 2) jJ [vinyl chloride-motuptil 7! Rate copolymer (emulsion polymer, average degree of polymerization 1400. Motuptil 7 malate content: 3 mol%) (Note 5) Epoxy group-containing acrylic rubber (Toa Paint ■
(Note 4) 4.4'-diphenylmethane diisocyanate (Note 5) -caprolactam-blocked isophorone diisocyanate (Note 6) Flexible resin (Nippon Soda's Polymer resin FFB-12B) ) (Note 7) Butyl ether melamine resin (Mitsui Toatsu Chemical ■
(Note 8) Tolylene diisocyanate (Note 9) Ba-Kn system From the results in Table 6, polyisocyanate system, plastic isocyanate system, epoxy resin, butyl ether melamine resin as a crosslinking agent. It can be seen that any of them can be used, and that the amount added is preferably 0.1 to 5 parts. It is understood that isocyanate-based crosslinking agents are particularly preferred from the viewpoint of compression recovery properties.

Moreover, if no crosslinking agent is added (Comparative Example 3), the Comparative Example 1
Similarly, cell roughness already occurs after 6 times foaming, and it is impossible to increase the foaming ratio beyond that, and the compression recovery property is also poor.

Examples 19 to 21 and Comparative Examples 4 to 5 The resin components and additives shown in Table 4 were mixed uniformly using a Nemo mixer, and the mixture was coated onto release paper (surface treated with a knife) to a thickness of 0.5 mm. After applying with
Heat it for 1 minute in the open at 50c'a to gel it,
Further, the mixture was heated with C, 220'O oats for 1 minute and foamed to obtain a foam. In Table 3, the acrylic rubber used was one that had been previously dissolved in a sanitiser (dibutyl 7-thalerate) at a concentration of more than 15 times.

# The foaming ratio and physical properties of each foam obtained! It is shown in Table 4.

(Note 1) Vinyl chloride homopolymer (emulsion polymer, average degree of polymerization 1000') (Note 2) Vinyl chloride-2-hydroxypropyl acrylate-docopolymer (emulsion polymer, average degree of polymerization 1200.2')
Hydroxypropyl acrylate content = 2.5 mol%
) (Note 3) Hydroxyl group-containing acrylic rubber (NR-02 manufactured by Nissin Chemical Industry Co., Ltd.) (Note 4)) Rimethylolpropane tolylene diisocyanate adduct (Note 5) Oa-211 yarn Examples 22 to 24 and comparative examples 6-7 The resin components and additives shown in Table 5 were mixed, kneaded, and gelated using a mixing roll heated to 14,000 ℃.
After a minute, a 1.5-inch thick sheet was taken out.

110g of this material has an inner volume of 10 x 10 x 16
! After filling the iron mold with DA plating on the inside using l, the hot plate area is filled! The mold was placed in a 3 x 55 am steam-heated 50 ton press, and an external pressure of 100 kg per unit area was applied to increase the steam pressure to 7 kp/a.
m'' for 10 minutes to foam.

Next, the steam was discharged, and tap water with a water temperature of 17°0 was introduced to cool it for 7 minutes, and the external pressure of the press was removed.The foam was taken out from the mold and introduced into a hot air circulation oven at 100°0 for 20 minutes. The foamable resin composition was expanded by heating.

Table 5 shows the expansion ratio and physical properties of the obtained foam.

(Note 1) Vinyl chloride homopolymer (suspension polymer, average degree of polymerization 1100) (Note 2) Vinyl chloride-2-hydroxypropyl acrylate copolymer (emulsion polymer, average degree of polymerization 1200.2-
(Note 3) Hydroxyl group-containing acrylic rubber (NR-Q2 mentioned above)
) (Note 4) ε-Kakabura Utamputsu Isophorone Diisocyanate (Note 5) Based on the results in Table 5 for Ba-Zn-an system, the foamable resin composition of the present invention has excellent heat resistance and resistance even in pressure foaming. It can be seen that the chemical properties are greatly improved, and the compression recovery properties are also improved.

Claims (1)

[Scope of Claims] 1 (A) 100 parts by weight of vinyl chloride polymer or copolymer, (B) 0.5 to 30 parts by weight of acrylic rubber, and (0)
A vinyl foam resin composition comprising 0.1 to 5 parts by weight of a crosslinking agent, a blowing agent, a stabilizer, and a plasticizer. 2. The resin composition according to claim 1, wherein the acrylate rubber is an elastic body containing an acrylic acid alkyl ester as a main component, and is a copolymer with a rigid component having an active group serving as a crosslinking point. . 3. The resin composition according to claim 1, wherein the crosslinking agent has two functional groups in its molecule that can react with the active groups of the acrylate rubber.