JPH10130445A - Vinyl chloride resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtian a vinyl chloride resin compsn. which does not cause the deposition of solids at the top of a metal mold, etc., and is excellent in long- term moldability and in the surface smoothness of a molded item obtd. therefrom by compounding a vinyl chloride resin with specified amts. of fly ash and an acrylic process aid. SOLUTION: This compsn. comprises 100 pts.wt. vinyl chloride resin, 0.1-50 pts.wt. fly ash, and 0.1-10 pts.wt. acrylic process aid. The vinyl chloride resin includes a vinyl chloride homopolymer, of vinyl chloride and an unsatd. monomer copolymerizable therewith, a graft copolymer obtd. by grafting vinyl chloride onto a polymer, etc., and each of these polymers, pref. having average degree of polmn. of 500 to 2,000 may be used alone or two or more polymers may be used jointly. An alkyl acrylate homo- or copolymer is used as the process aid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vinyl chloride resin composition having excellent long-term moldability and excellent surface smoothness of a molded article obtained.

[0002]

2. Description of the Related Art Vinyl chloride resins are inexpensive.
Because of its excellent physical properties such as impact resistance and heat resistance, and chemical properties such as solvent resistance and acid resistance, it is formed into various shapes by extrusion or injection molding, and is used in a wide range of applications such as building materials and pipe materials. Used in Due to the fact that the decomposition temperature and the molding temperature of the vinyl chloride resin are close to each other, even if only the vinyl chloride resin is extrusion-molded, a good molded product cannot be obtained. For this reason, when extruding the vinyl chloride resin, various additives such as a stabilizer and a solvent are blended.

However, when such a composition in which an additive is blended with a vinyl chloride resin is subjected to molding for a long period of time, a phenomenon occurs in which a solid adheres to the tip of a mold of a molding machine. This solid material, scratches, streaks, etc. on the molded product,
It adheres to the molded product itself. Therefore, in order to obtain a good molded product, it is necessary to frequently remove this solid from the tip of the mold, which has been a cause of a decrease in productivity.

Japanese Patent Application Laid-Open No. 4-178449 discloses a technique for reducing the adhesion of solids to the tip of a mold by using needle-like materials such as wollastonite and potassium titanate as additives. However, it cannot be said that it is exerting a sufficient effect. Also, Japanese Patent Application Laid-Open No. 1-1745
No. 51 discloses a technique for reducing the adhesion of solid matter to the tip of a mold by using titanium oxide and magnesium hydroxide as additives, but titanium oxide is often present in the solid matter. And may increase the adhesion of solids.

[0005]

DISCLOSURE OF THE INVENTION In view of the above, the present invention provides a vinyl chloride resin composition having no long-term moldability and excellent surface smoothness of the resulting molded article without adhesion of solid matter to the tip of the mold. The purpose is to provide things.

[0006]

The present invention provides a vinyl chloride resin comprising 100 parts by weight of a vinyl chloride resin, 0.1 to 50 parts by weight of fly ash, and 0.1 to 10 parts by weight of an acrylic processing aid. It is a resin composition. Hereinafter, the present invention will be described in detail.

The vinyl chloride resin used in the present invention is not particularly restricted but includes, for example, a vinyl chloride homopolymer; a vinyl chloride monomer and a polymerizable monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer. Copolymers: Graft copolymers obtained by graft copolymerizing a vinyl chloride monomer with a polymer, and the like. These may be used alone or in combination of two or more.

The polymerizable monomer having an unsaturated bond is not particularly limited as long as it has a radical-reactive double bond and can be copolymerized with a vinyl chloride monomer by a radical polymerization initiator. Α-olefins such as ethylene, propylene and butylene; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as butyl vinyl ether and cetyl vinyl ether;
(Meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl acrylate, and phenyl methacrylate; aromatic vinyls such as styrene and α-methylstyrene; halogenation such as vinylidene chloride and vinylidene fluoride Vinyls; N-substituted maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide; These may be used alone or in combination of two or more.

The polymer to be graft-copolymerized with the vinyl chloride monomer is not particularly limited as long as it is capable of graft-copolymerizing the vinyl chloride monomer. Examples thereof include ethylene-vinyl acetate copolymer and ethylene-acetic acid. Vinyl-carbon monoxide copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate-carbon monoxide copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, acrylonitrile-butadiene copolymer , Polyurethane, chlorinated polyethylene; chlorinated polypropylene and the like.
These may be used alone or in combination of two or more.

The above-mentioned vinyl chloride resin has an average degree of polymerization of 50.
The thing of 0-2000 is preferred. If it is less than 500,
If the mechanical properties of the obtained molded product are reduced, and if it exceeds 2,000, the melt viscosity at the time of molding becomes high, and molding becomes difficult. More preferably, it is 600-1400.

The fly ash used in the present invention is used for removing solid matter adhering to the tip of a mold or the like. The fly ash preferably has an average particle size of 0.1 to 30 μm. When the thickness is less than 0.1 μm, the material is liable to be scattered at the time of inputting and mixing the raw materials.
If it exceeds μm, the appearance of the obtained molded article is impaired.

In the present invention, the amount of the fly ash is 0.1 to 50 parts by weight based on 100 parts by weight of the vinyl chloride resin. If the amount is less than 0.1 part by weight, the effect of removing solids is reduced. If the amount is more than 50 parts by weight, molding becomes difficult, and the appearance of the obtained molded article is impaired. . Preferably,
1 to 20 parts by weight.

The acrylic processing aid used in the present invention is not particularly restricted but includes, for example, homopolymers or copolymers of alkyl methacrylates such as methyl methacrylate, ethyl methacrylate and butyl methacrylate; , A copolymer with an alkyl acrylate such as ethyl acrylate and butyl acrylate; and the above-mentioned alkyl methacrylate and an aromatic vinyl compound such as styrene, α-methylstyrene and vinyl toluene, and a vinyl cyanide compound such as acrylonitrile and methacrylonitrile. And copolymers. These may be used alone or in combination of two or more.

In the present invention, the addition amount of the acrylic processing aid is 0.1 to 10 parts by weight based on 100 parts by weight of the vinyl chloride resin. If the amount is less than 0.1 part by weight, the appearance of the obtained molded article is impaired, and if it exceeds 10 parts by weight, the Amp becomes high during molding and molding becomes difficult, so the content is limited to the above range. Preferably, 0.3 to
6 parts by weight.

The vinyl chloride resin composition of the present invention may contain, if necessary, a heat stabilizer, a lubricant, a modifier, a filler, an antioxidant, an antistatic agent, a pigment and the like. Further, a plasticizer may be added to such an extent that the effect of the present invention is not impaired.

The stabilizer is not particularly limited, and examples thereof include a lead stabilizer, an organotin stabilizer, and a metal soap stabilizer. Examples of the lead-based stabilizer include tribasic lead sulfate, dibasic lead phosphite, lead stearate, dibasic lead stearate and the like. Examples of the organic tin-based stabilizer include organic tin mercapto, organic tin malate, and organic tin laurate. These may be used alone or in combination of two or more.

The lubricant is not particularly restricted but includes, for example, polyethylene waxes and paraffin waxes; various ester waxes; organic acids such as stearic acid and ricinoleic acid; organic alcohols such as stearyl alcohol; dimethylbisamide And the like.

The modifier is not particularly restricted but includes, for example, acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, chlorinated polyethylene, acrylic rubber and the like. The filler is not particularly limited, and includes, for example, calcium carbonate, talc, clay, mica, barium sulfate and the like.

The plasticizer is not particularly restricted but includes, for example, dibutyl phthalate (DBP), diheptyl phthalate (DHP), di-2-ethylhexyl phthalate (DOP), diisononyl phthalate (DINP), diundecyl phthalate (DUP) And phthalic acid esters such as dibutylbenzyl phthalate (BBP); di-2-ethylhexyl adipate (DOA), diisononyl adipate (DINA), diisodecyl adipate (DID)
And adipic acid esters such as A).

The vinyl chloride resin composition of the present invention may be in the form of powder or granulated pellets during molding. The method for obtaining a molded article from the vinyl chloride resin composition of the present invention is not particularly limited, and various conventionally known molding methods can be employed. For example, when forming into a pipe, a deformed product, or the like, it can be formed by extrusion molding, and when forming into a joint or the like, it can be formed by injection molding. The extruder used for the extrusion molding is not particularly limited, and an appropriate one can be used. Examples thereof include a single screw extruder, a conical twin screw extruder, and a parallel twin screw extruder. In general, in the case of hot runner injection molding, since the runner portion is heated and the resin is retained, it is easy for solid matter to adhere,
The vinyl chloride resin composition of the present invention can also be suitably molded by hot runner injection molding.

[0021]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Examples 1 to 4 and Comparative Examples 1 to 5 Vinyl chloride resin (polymerization degree 100
0, manufactured by Tokuyama Sekisui Co., Ltd.), tribasic lead sulfate (TL # 700
0, manufactured by Sakai Chemical Industry Co., Ltd.), dibasic lead sulfite (NB-20)
0, manufactured by Sakai Chemical Industry Co., Ltd.), fly ash (Superflow, manufactured by Chichibu Onoda), acrylic processing aid (P-53)
0A, manufactured by Mitsubishi Rayon Co., Ltd.) and stearic acid (F-
3, Kawasaki Fine Chemical Co., Ltd.) was stirred and mixed with a super mixer (100 l, manufactured by Kawata Co., Ltd.) to obtain a vinyl chloride resin composition.

The obtained vinyl chloride resin composition was subjected to a single screw extruder (GT-32, manufactured by Plastics Engineering Laboratory).
A 30 × 5 mm flat plate was extruded under the following extrusion conditions. (Barrel temperature) C1: 160 ° C, C2: 170 ° C, C
3: 180 ° C (mold temperature) AD: 185 ° C, D1: 185 ° C, D2:
185 ° C (rotation speed) 40 rpm

In the above Examples and Comparative Examples, the moldability and the appearance of the obtained flat plate were evaluated as follows, and the results are shown in Table 1. (1) Moldability The load at the time of molding and the state of adhesion of the solid matter to the mold were evaluated. Regarding the state of the solid matter attached to the mold, the molding was finished one hour after the start of extrusion molding, the mold was disassembled, and the presence or absence of the solid matter was visually observed. (2) Appearance The surface smoothness of the obtained molded article was visually observed.

[0025]

[Table 1]

Examples 5 to 7 and Comparative Examples 6 to 8 Vinyl chloride resins (polymerization degree: 600,
Tokuyama Sekisui Co., Ltd.), tribasic lead sulfate (TL # 7000, manufactured by Sakai Chemical Industry Co., Ltd.), dibasic lead sulfite (NB-200, manufactured by Sakai Chemical Industry Co., Ltd.), fly ash (Superflow, manufactured by Chichibu Onoda Co., Ltd.) ), Acrylic processing aids (P-530A,
Super Mixer (100%, manufactured by Mitsubishi Rayon Co., Ltd.) and stearic acid (F-3, manufactured by Kawasaki Fine Chemical Co., Ltd.)
1, manufactured by Kawata Co., Ltd.) to obtain a vinyl chloride resin composition.

The obtained vinyl chloride resin composition was granulated with a twin-screw extruder (OSC-30, manufactured by Nagata Seisakusho) under the following extrusion conditions. (Barrel temperature) C1: 120 ° C, C2: 130 ° C, C
3: 140 ° C (mold temperature) AD: 145 ° C, D1: 145 ° C, D2:
145 ° C (Rotation speed) SC: 35 rpm, Feeder: 20 rpm (Cut method) Hot cut

Using the resin composition granulated as described above, injection molding was performed under the following conditions. Using a 100 t injection molding machine (J100E-C5, manufactured by Japan Steel Works, Ltd.) as an injection molding machine, a pipe joint having an inner diameter of 20 mm was obtained. (Molding temperature) B1: 170 ° C., B2: 180 ° C., B3:
185 ° C, NH: 190 ° C (Mold temperature) 50 ° C (Injection speed) 80% (Injection pressure) 70%

With respect to the moldability and the appearance of the obtained pipe joint in the above Examples and Comparative Examples, the following evaluations were made. The results are shown in Table 2. (1) Moldability The presence or absence of burns during molding was visually observed, and those without burns were evaluated as 、, and those with burns were evaluated as x. (2) Appearance The external appearance of the obtained pipe joint was visually observed, and those without white solids were evaluated as ○, and those with white solids were evaluated as x.

[0030]

[Table 2]

[0031]

As described above, the vinyl chloride resin composition of the present invention does not adhere to a mold or a molded product because it has the above-mentioned structure. Therefore, it has excellent long-term moldability in the sense of stable running, and the resulting molded article has excellent surface smoothness and excellent appearance.

Claims (1)

[Claims] 1. A vinyl chloride resin composition comprising 100 parts by weight of a vinyl chloride resin, 0.1 to 50 parts by weight of fly ash, and 0.1 to 10 parts by weight of an acrylic processing aid. .