JPH08113663A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE: To obtain a vinyl chloride resin compsn. which is excellent in releasability from a mold and gives a molded foam having a good appearance and uniform cells by compounding a vinyl chloride resin, a specific olefin oligomer, and a thermally decomposable blowing agent. CONSTITUTION: This resin compsn. contains 100 pts.wt. vinyl chloride resin, 0.1-20 pts.wt. olefin oligomer obtd. by subjecting a 20C or higher α-olefin and a 1--20C unsatd. fatty acid to addition reaction followed by polymn. and 0.1-5 pts.wt. thermally decomposable blowing agent.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a vinyl chloride resin composition.

[0002]

2. Description of the Related Art Conventionally, vinyl chloride resin has been used for impact resistance,
It has been widely used in building materials because of its excellent physical properties such as heat resistance; chemical properties such as solvent resistance, acid resistance, and alkali resistance. However, its use as a foam was further developed. Is being used in a wider range of applications.

Such a vinyl chloride resin foam molded article generally uses a pyrolytic inorganic or organic foaming agent,
It is manufactured by extrusion. For example, as a foaming agent, a heat-decomposable organic foaming agent made of an azo compound and a heat-decomposable inorganic foaming agent made of sodium bicarbonate are used in combination, and further a methacrylic acid ester resin (processing aid) and calcium carbonate, talc, A highly foamable vinyl chloride resin composition containing a filler such as clay, asbestos or silica (Japanese Patent Publication No. 63-9540) is disclosed. From this composition, a uniform and fine foam cell structure is formed. It is described that a foamed molded product having a skin layer having a high surface height as well as having an excellent surface gloss can be obtained.

However, in general, in a foamable vinyl chloride resin composition, as compared with a non-foaming hard vinyl chloride resin composition, the resin adheres to a metal part during melting, for example, a barrel or a screw of an extruder. There is a problem that it is easy and molding becomes difficult.

In order to solve this problem, polyvalent esters synthesized from pentaerythritol and fatty acids, polyvalent esters synthesized from dipentaerythritol and fatty acids, etc. have been used as external lubricants. However, while these polyhydric esters improve the metal releasability, they delay gelation, which causes problems such as roughening the surface of the molded product and difficulty in obtaining uniform foam cells.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an object thereof is to exhibit excellent metal releasability at the time of molding and to provide a foam cell having a good appearance and a uniform appearance. Another object of the present invention is to provide a vinyl chloride-based resin composition capable of obtaining a foamed molded article having the above.

[0007]

The vinyl chloride resin composition of the present invention comprises a vinyl chloride resin (a), an olefin oligomer (b) and a thermal decomposition type foaming agent (c).

As the vinyl chloride resin (a), those conventionally known can be used, for example, vinyl chloride homopolymers, vinyl chloride and polymerizable monomers other than vinyl chloride. A graft copolymer obtained by grafting vinyl chloride onto a polymer other than vinyl chloride;
A chlorinated vinyl chloride resin obtained by post-chlorinating these (co) polymers by a conventionally known method; a mixture of the above (co) polymers and the like can be mentioned.

The polymerizable monomer other than vinyl chloride is not particularly limited as long as it has a reactive double bond, and for example, α-such as ethylene, propylene and butylene.
Olefin; Vinyl acetates such as vinyl acetate and vinyl propionate; Vinyl ethers such as butyl vinyl ether and cetyl vinyl ether; Methyl acrylate
Acrylic acid esters such as ethyl acrylate; Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, phenyl methacrylate; styrene, α
-Aromatic vinyls such as methylstyrene; vinyl halides such as vinylidene chloride and vinyl fluoride; N- such as N-phenylmaleimide and N-cyclohexylmaleimide
Substituted maleimides and the like may be used alone or in combination of two or more.

The polymer other than vinyl chloride used in the graft copolymer is not particularly limited, and examples thereof include ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer, ethylene. -Ethyl acrylate copolymer, ethylene-ethyl acrylate-carbon monoxide copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, acrylonitrile-butadiene copolymer, polyurethane resin, chlorinated polyethylene resin, chlorine And the like. These may be used alone or in combination of two or more.

When the average degree of polymerization of the above vinyl chloride resin is small, the mechanical properties of the obtained molded article, particularly impact resistance, is lowered, and when it is large, the melt viscosity at the time of molding becomes high and molding becomes difficult. Since the foam cells will be non-uniform,
It is preferably 400 to 2,000, more preferably 500.
~ 1,200.

The olefin oligomer (b) is α-
It is obtained by subjecting an olefin to a saturated fatty acid in the presence of an organic peroxide, and then polymerizing an α-olefin to which a saturated fatty acid is added.

If the carbon number of the α-olefin becomes small, the melt viscosity of the obtained olefin oligomer (b) becomes small and the effect of metal releasability cannot be exhibited. Therefore, it is limited to 20 or more, preferably 30 or more. Is.
Further, even if the carbon number becomes too large, the effect of metal releasability cannot be exhibited, so that the carbon number is preferably 100 or less.

If the carbon number of the saturated fatty acid increases, the addition reaction to the α-olefin becomes difficult.
Limited to 0 or less. Such saturated fatty acids include
Examples thereof include acetic acid, butyric acid, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid and the like, with acetic acid, butyric acid and caproic acid being preferred.

The reaction of adding the fatty acid to the above α-olefin is carried out by adding an organic peroxide to the mixture of both while heating and stirring. The method for polymerizing the α-olefin added with the fatty acid is not particularly limited, and a conventionally known olefin polymerization method is used.

The olefin oligomer (b) is not particularly limited, but in order to further exert the effect of metal releasability, the weight average molecular weight is 10,000 to 500,000 and the acid value is 5.
It is preferably at least mgKOH / g, more preferably at least 10 mgKOH / g.

In the vinyl chloride resin composition of the present invention, when the amount of the above-mentioned olefin oligomer (b) is small, the effect of metal releasability is hardly exhibited, and when the amount is large, the slipperiness of the vinyl chloride resin is strong. Since the gelation becomes slower and the foamability and the appearance of the molded article are adversely affected, it is limited to 0.1 to 20 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the vinyl chloride resin. It is a department.

Examples of the heat-decomposable foaming agent (c) include a heat-decomposable inorganic foaming agent and a heat-decomposable organic foaming agent, which may be used alone or in combination. Examples of the thermal decomposition type inorganic foaming agent include sodium bicarbonate, ammonium bicarbonate, ammonium carbonate and the like, and sodium bicarbonate is preferable from the viewpoint of toxicity and foamability.

Further, as the above pyrolyzable organic foaming agent,
For example, nitroso compounds such as N, N′-dinitrosopentamethylenetetramine and N, N′-dimethyl-N, N′-dinitrosoterephthalamide; azo compounds such as azodicarbonamide and azobisisobutyronitrile; benzene Examples thereof include sulfonyl hydrazide compounds such as sulfonyl hydrazide and toluene sulfonyl hydrazide, and these may be used alone or in combination of two or more kinds.

In the vinyl chloride resin composition of the present invention, if the blending amount of the above-mentioned pyrolyzable organic foaming agent (c) is small, almost no foaming occurs and a uniform foamed molded article cannot be obtained. Therefore, since a uniform cell structure cannot be obtained, the amount is limited to 0.1 to 5 parts by weight, preferably 0.3 to 3 parts by weight, based on 100 parts by weight of the vinyl chloride resin (a).

In molding the vinyl chloride resin composition of the present invention, a polymethylmethacrylate-based processing aid, if necessary, in order to improve moldability, thermal stability and the like,
A heat stabilizer, an antioxidant, an antistatic agent, an ultraviolet absorber, a lubricant, a filler, a flame retardant, a plasticizer, a pigment, a paint and the like may be added appropriately.

Examples of the heat stabilizers include tin-based stabilizers such as dibutyltin malate and dibutyltin mercapto; organometallic soap-based stabilizers such as calcium stearate, barium stearate and zinc stearate; and lead compound-based heat stabilizers. Can be mentioned.

Examples of the above-mentioned lubricants include aliphatic hydrocarbons such as paraffin wax and polyethylene wax; higher aliphatic alcohols such as stearyl alcohol; higher fatty acid such as stearic acid and hydroxystearic acid;
Examples thereof include monoalcohol fatty acid ester type such as butyl stearate; polyhydric alcohol fatty acid ester type such as glycerin monostearate and glycerin tristearate.

Examples of the filler include calcium carbonate, clay, mica, glass fiber, and the like, and examples of the flame retardant include halogen-based, phosphorus-based, and metal oxide-based oxides such as antimony trioxide.

The method for molding a foam from the vinyl chloride resin composition of the present invention is not particularly limited, and for example, an extrusion molding method is preferably adopted. As the extrusion molding method, for example, a modified forming method using a pipe die, a selka foam molding method,
A grain-like foam molding method using a porous die may be used. Any extruder may be used as the extruder used in the extrusion molding method, and a single-screw extruder, a twin-screw extruder, or the like is preferably used.

In the case of molding by an extruder, the molding temperature is
The linder temperature is the supply side temperature (hereinafter C ₁Is 80)
160 ° C, central temperature (hereinafter C₂Is said to be 100-1
80 ° C and discharge side temperature (hereinafter C₃Is called) 130-2
It is preferable to set each temperature to 00 ° C, and the mold temperature (below
The lower temperature D) is preferably 120 to 200 ° C.

[0027]

Embodiments of the present invention will be described below. Synthesis of Olefin Oligomer Olefin oligomer was synthesized from a predetermined amount of α-olefin oligomer, saturated fatty acid and organic peroxide shown in Table 1. In addition, (1) of the obtained olefin oligomer
The molecular weight and (2) acid value were measured by the following methods and are shown in Table 1. (1) Molecular weight Gel permeation chromatograph ("C" manufactured by Tosoh Corporation
P-8000 series ”) was used to measure the number average molecular weight and the weight average molecular weight. (2) Acid value It was measured according to JIS K3504.

[0028]

[Table 1]

Examples 1 to 6 and Comparative Examples 1 to 4 Predetermined amounts of vinyl chloride resins shown in Tables 2 and 3 (average degree of polymerization: 80)
0) (a), the synthesized olefin oligomer (b) and the thermal decomposition type inorganic foaming agent (c) (“Cerbon SC-D” manufactured by Eiwa Chemical Industry Co., Ltd.), and a tin stabilizer (Sankoki Co., Ltd.). 2 parts by weight of "ONZ-142F", 5 parts by weight of an acrylic processing aid ("Metablene P-530" manufactured by Mitsubishi Rayon Co., Ltd.), calcium carbonate ("CC manufactured by Shiraishi Calcium Co., Ltd."
R ”), 5 parts by weight, glycerin monostearate (“ Rikemal S-100 ”manufactured by Riken Vitamin Co.) and 1 part by weight, and an ester-based lubricant (“ SL-02 ”manufactured by Riken Vitamin Co.).
Two parts by weight were supplied to a Henschel mixer and uniformly mixed to obtain a vinyl chloride resin composition.

The resulting vinyl chloride resin composition was applied to a single-screw extruder having the following specifications ("GT manufactured by Plastic Engineering Laboratory Co., Ltd."
-32-A ") and molded under the following molding conditions to obtain a vinyl chloride resin foam. [Extruder specifications] 1) Cylinder: diameter 300 mm 2) Screw: L / D = 28 3) Mold: T die, lip: width 150 x thickness 2 mm [Molding conditions] 1) Molding temperature: C ₁ = 150 ° C , C ₂ = 175 ° C., C ₃
= 180 ° C., D = 175 ° C. 2) Screw rotation speed: 20 rpm

The vinyl chloride resin foams obtained in the above Examples and Comparative Examples were evaluated as follows, and the results are shown in Tables 1 and 2. (1) Density AST of apparent density of vinyl chloride resin foam obtained
It measured based on MD1565.

(2) Cell Diameter The cross section of the obtained vinyl chloride resin foam was observed with an optical microscope to measure the average cell diameter.

(3) State of Foam Cell At the same time as observing the bubble diameter, the state of the foam cell was observed.
The evaluation was made according to the following criteria. ◯: The cells are uniformly dispersed, Δ: The cell dispersion state is slightly non-uniform, x: The cell dispersion state is non-uniform.

(4) Appearance The appearance of the obtained vinyl chloride resin foam was evaluated according to the following criteria. ◯: Good, Δ: Some defective parts, ×: Bad

(5) Metal releasability After the vinyl chloride resin composition was extruded for 1 hour,
The mold was disassembled and the screw was taken out, and the resin adhesion state to the mold and the screw was observed and evaluated according to the following criteria. ◯: No resin adhered, Δ: Slight resin adhered,
X: A large amount of resin is attached

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

EFFECT OF THE INVENTION The vinyl chloride resin composition of the present invention is as described above, the resin does not adhere to the metal part on the molding machine at the time of molding, the long-term thermal stability is excellent, and the obtained foamed molded product is uniform. Since it has a structure of various foam cells and has a good appearance, it can be suitably used for building materials such as deck materials, sizing materials, roofing materials, heat insulation applications, sound insulation applications, and the like.

Claims (1)

[Claims] 1. (a) 100 parts by weight of vinyl chloride resin,
(B) 1 to 10 carbon atoms in α-olefin having 20 or more carbon atoms
Chloride characterized by comprising 0.1 to 20 parts by weight of an olefin oligomer obtained by subjecting 20 saturated fatty acids to an additional reaction and then performing a polymerization reaction, and (c) 0.1 to 5 parts by weight of a thermal decomposition type blowing agent. Vinyl resin composition.