JP7285709B2 - Vinyl chloride resin composition and molding thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vinyl chloride resin composition, and more particularly to a vinyl chloride resin composition that can be suitably used for building materials such as sashes, and molded products thereof.

The sashes attached to the openings of the building frame are used differently depending on the region. Resin has better heat insulation than metal, so resin sashes are suitable for cold regions, but for regions where heat insulation is not required, metal sashes made entirely of metal materials such as aluminum are preferred. used. In recent years, the appearance and design of building materials such as window frames and sashes have become more important, and resin sashes, which are easier to impart design than metal sashes, are attracting attention. Therefore, there is a demand for resin sashes even in regions where heat insulation is not required.

Resin sashes use hard vinyl chloride resins, which are excellent in mechanical strength, weather resistance, heat insulation, and the like. On the other hand, rigid vinyl chloride resin has a large coefficient of linear expansion of about 8×10 ^-5 /°C, so in areas with large temperature differences, metal sashes with excellent dimensional stability have to be used. The problem of stability is one of the reasons why resin sashes are not popularized.

By the way, adding a filler (filler) is known as a general means for lowering the linear expansion coefficient of a resin. For example, in rigid vinyl chloride resins used for building materials such as rain gutters, the coefficient of linear expansion is reduced by adding inorganic fillers such as talc and calcium carbonate. However, although the coefficient of linear expansion decreases as the amount of the inorganic filler added increases, there is a problem that physical properties of the resin such as impact resistance decrease.

In response to the above problems, for example, Patent Documents 1 and 2 disclose chlorides that reduce the coefficient of linear expansion while maintaining impact resistance by using an inorganic filler having a particle shape with a high aspect ratio. Vinyl-based resins have been proposed.

Japanese Patent Application Laid-Open No. 2004-43774 JP 2009-97175 A

As proposed in Patent Documents 1 and 2, etc., the use of a specific inorganic filler can reduce the linear expansion coefficient while maintaining impact resistance, but the addition of the inorganic filler deteriorates the processability. may affect the appearance of the molding. In particular, among building materials, the appearance and design of sashes and the like are regarded as important, and problems such as roughening of the surface of molded products due to deterioration of workability arise.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a vinyl chloride resin composition which has a low coefficient of linear expansion, is excellent in impact resistance, and provides a molded article having a smooth surface and no rough surface.

As a result of extensive studies to solve the above problems, the present inventors have found that by adding a specific aluminosilicate to a vinyl chloride resin, the linear expansion coefficient is low, the impact resistance is excellent, and the surface is smooth. It was found that moldings without rough skin can be obtained by The present invention is based on such findings.

That is, the gist of the present invention is as follows.
[1] (A) a vinyl chloride resin;
(B) nepheline cyanite;
comprising
The (B) nepheline cyanite is contained in an amount of 5 to 40 parts by mass with respect to 100 parts by mass of the (A) vinyl chloride resin,
A vinyl chloride resin composition characterized by having a coefficient of linear expansion of less than 5×10 ⁻⁵ /°C.
[2] The nepheline cyanite (B) has a value (D ₅₀ ) of 3 to 3 at a cumulative frequency of 50% in a number-based cumulative frequency distribution curve measured using a laser diffraction/scattering particle size distribution analyzer. The vinyl chloride resin composition of [1] having a particle size of 10 µm.
[3] A molded article made of the vinyl chloride resin composition of [1] or [2].
[4] The molded product of [3] obtained by extrusion molding.
[5] The molding of [3] or [4] used for building materials.
[6] The molding of [5], wherein the building material is a sash.

According to the present invention, by adding a predetermined amount of nepheline cyanite, which is a kind of aluminosilicate, to a vinyl chloride resin, the linear expansion coefficient is low, the impact resistance is excellent, and the surface is smooth and free from surface roughness. A vinyl-based resin molding can be obtained.

The vinyl chloride resin composition according to the present invention contains (A) a vinyl chloride resin and (B) nepheline cyanite as essential components. Each component constituting the vinyl chloride resin composition according to the present invention will be described below.

<(A) Vinyl chloride resin>
The (A) vinyl chloride resin used in the vinyl chloride resin composition according to the present invention refers to all polymers having a group represented by —CH ₂ —CHCl—, and homopolymers of vinyl chloride; Copolymers of vinyl monomers and other monomers having unsaturated bonds copolymerizable with the vinyl chloride monomers; graft copolymers obtained by graft copolymerizing vinyl chloride monomers onto polymers other than polyvinyl chloride resins, etc. is mentioned. The polyvinyl chloride-based resin may be used alone or in combination of two or more. Also, the polyvinyl chloride resin may be further chlorinated. Examples of methods for chlorinating polyvinyl chloride-based resins include thermal chlorination and photochlorination.

Other monomers having unsaturated bonds copolymerizable with vinyl chloride monomers include, for example, α-olefins such as ethylene, propylene and butylene; vinyl esters such as vinyl acetate and vinyl propionate; butyl vinyl ether and cetyl vinyl ether. vinyl ethers such as; methyl (meth) acrylate, ethyl (meth) acrylate, butyl acrylate and other (meth) acrylic acid esters; styrene, α-methyl styrene and other aromatic vinyls; N-phenylmaleimide, N-cyclohexyl Examples include N-substituted maleimides such as maleimide. The other monomers may be used singly or in combination of two or more.

Examples of polymers graft-copolymerized with vinyl chloride monomers include ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate-monoxide. Examples include carbon copolymers, ethylene-methyl methacrylate copolymers, ethylene-propylene copolymers, acrylonitrile-butadiene copolymers, polyurethanes, chlorinated polyethylenes, chlorinated polypropylenes, and the like. These polymers may be used individually by 1 type, and may use 2 or more types together.

In the present invention, from the viewpoint of improving the impact resistance, it is possible to suitably use those obtained by graft polymerization of the above-described (meth)acrylate monomers. The (meth)acrylate constituting the vinyl chloride graft copolymer is not particularly limited as long as it improves impact resistance, but from the viewpoint of improving impact resistance, the glass transition temperature of the homopolymer is -140. C. to less than 0.degree. C. is preferably an acrylic copolymer composed of a radically polymerizable monomer containing (meth)acrylate as a main component and a polyfunctional monomer. (Meth)acrylate means acrylate or methacrylate. Such (meth)acrylates include, for example, n-butyl acrylate (Tg: -4°C, only the temperature is shown in parentheses below), n-hexyl acrylate (-57°C), 2-ethylhexyl acrylate (-85 ° C), n-octyl acrylate (-85 ° C), n-nonyl acrylate, isononyl acrylate (-85 ° C), n-decyl acrylate (-70 ° C), lauryl acrylate, lauryl methacrylate (-65 ° C), ethyl Acrylate (-24°C), n-propyl acrylate (-37°C), n-butyl acrylate (-54°C), isobutyl acrylate (-24°C), sec-butyl acrylate (-21°C), n-hexyl acrylate (-21°C) -57°C), n-octyl methacrylate (-25°C), isooctyl acrylate (-45°C), n-nonyl methacrylate (-35°C), n-decyl methacrylate (-45°C) and the like. These can be used singly or in combination of two or more.

For the vinyl chloride-based resin obtained by graft polymerization of the above-mentioned (meth)acrylate monomer, an emulsified monomer liquid containing a mixed monomer, an emulsifying dispersant, etc. is prepared in advance, and then the emulsified monomer liquid is mixed with the vinyl chloride-based monomer and polymerized. can be obtained by The graft polymerization method is not particularly limited, and examples thereof include suspension polymerization method, emulsion polymerization method, solution polymerization method, bulk polymerization method, etc. Among these, suspension polymerization method is preferred.

Also, the polyvinyl chloride resin may be crosslinked. Examples of the method for cross-linking the polyvinyl chloride-based resin include a method of adding a cross-linking agent and a peroxide, a method of irradiating an electron beam, a method of using a water cross-linkable material, and the like.

The average degree of polymerization of the polyvinyl chloride resin is preferably 400 to 1600 or less, more preferably 600 to 1400, from the viewpoint of mechanical strength and moldability of the molded product. The average degree of polymerization was determined by dissolving a polyvinyl chloride resin in tetrahydrofuran (THF), removing insoluble components by filtration, and then removing the THF in the filtrate by drying. It is the average degree of polymerization measured according to the "Vinyl chloride resin test method".

As the (A) vinyl chloride resin in the present invention, a commercially available one may be used, for example, polyvinyl chloride "ZEST 1000Z" (average degree of polymerization: 1000) manufactured by Shin-Daiichi Vinyl Co., Ltd., Shin-Etsu Chemical Co., Ltd. The company's polyvinyl chloride "TK-800" (average degree of polymerization: 800), "TK-1000" (average degree of polymerization: 1000), etc. can be used.

<(B) Nepheline cyanite>
The vinyl chloride resin composition according to the present invention contains (B) nepheline cyanite as a filler. Inorganic fillers such as talc and calcium carbonate have been conventionally added to vinyl chloride resins in order to reduce the coefficient of linear expansion of molded products. impact resistance tends to decrease. As a filler capable of maintaining impact resistance while reducing the coefficient of linear expansion, wallathonite, which contains β-metacalcium silicate as a main component, is known. The processability is affected, and the surface of the obtained molded product sometimes causes so-called rough skin. Profile extrusion molding for obtaining molded products such as resin sashes and window frames, which require particularly high designability, requires a higher molding temperature. It has been difficult to obtain a molding that is excellent in impact resistance, has a smooth surface, and does not have rough surfaces. In the present invention, it was found that by using nepheline cyanite as a filler, a molded article having a low linear expansion coefficient, excellent impact resistance, a smooth surface and no rough surface can be obtained.

Nepheline cyanite (nepheline syenite) is a powdery rock that constitutes fine-grained silica-deficient silicates in the form of sodium-potassium-aluminosilicates. Nepheline cyanite is a naturally occurring rock composed of a mixture of sodium feldspar, potassium feldspar, and nepheline (55% sodium feldspar, 20% potassium feldspar, and 25% nepheline) with a chemical composition of It is a compound represented by (Na, K) _AlSiO4 .

As described above, nepheline cyanite is in the form of fine particles, but from the viewpoint of moldability such as dispersibility in resin and workability, the particle size is measured using a laser diffraction/scattering particle size distribution analyzer. In the number-based cumulative frequency distribution curve, the value (D ₅₀ ) at 50% cumulative frequency is preferably 3 to 10 μm. The cumulative frequency distribution curve can be measured using, for example, a laser diffraction/scattering particle size distribution analyzer (SALD-2100, manufactured by Shimadzu Corporation).

From the viewpoint of maintaining impact strength, the particle size of nepheline cyanite is preferably such that the value (D ₉₀ ) at 90% cumulative frequency is 20 μm or less, more preferably 15 μm, in the cumulative frequency distribution curve. be. In order to adjust the particle size of nepheline cyanite within the above range, it can be appropriately adjusted depending on the pulverization conditions when pulverizing (crushing) the raw material. In addition, when the pulverization time is short, the particle size of the material to be pulverized tends to be large, and when the pulverization time is long, the particle size tends to be small.

The particle shape of nepheline cyanite preferably has an aspect ratio of 2 or less, more preferably close to 1. The aspect ratio is a numerical value obtained by dividing the major axis of the particle by the minor axis, and approaches 1 as the particle is closer to a true sphere. The aspect ratio of nepheline cyanite particles is, for example, observed with an electron microscope, randomly selecting 100 particles, calculating the aspect ratio from the major axis and minor axis of each particle, and averaging them. .

Nepheline cyanite having the shape described above may be commercially available, for _example , trade name " _NESPER " manufactured by Toyo Fine Chemical Co., Ltd. 1) etc. can be used.

(B) nepheline cyanite is contained in an amount of 5 to 40 parts by mass with respect to 100 parts by mass of vinyl chloride resin (A). If it is less than 5% by mass, the molded product is excellent in processability such as surface roughness, but the effect of reducing the coefficient of linear expansion is insufficient. On the other hand, if it exceeds 40 parts by mass, the impact resistance deteriorates. (B) Nepheline cyanite is preferably blended in an amount of 10 to 30 parts by mass.

<Other ingredients>
The vinyl chloride resin composition according to the present invention may optionally contain heat stabilizers, stabilizing aids, lubricants, processing aids, antioxidants, light stabilizers, colorants, fillers, and the like. .

The heat stabilizer is not particularly limited. Organotin stabilizers such as tin laurate polymers, lead stabilizers such as lead stearate, dibasic lead phosphite, tribasic lead sulfate, calcium-zinc stabilizers, barium-zinc stabilizers, barium - Cadmium-based stabilizers and the like are included. These may be used alone or in combination of two or more.

The stabilizing aid is not particularly limited, and examples thereof include epoxidized soybean oil, epoxidized linseed oil, epoxidized tetrahydrophthalate, epoxidized polybutadiene, and phosphate ester. These may be used alone or in combination of two or more.

The lubricant is not particularly limited, and examples thereof include montanic acid wax, paraffin wax, polyethylene wax, stearic acid, stearyl alcohol, and butyl stearate. These may be used alone or in combination of two or more.

The processing aid is not particularly limited, and examples thereof include acrylic processing aids that are alkyl acrylate/alkyl methacrylate copolymers having a weight average molecular weight of 100,000 to 2,000,000. Specific examples include n-butyl acrylate. /methyl methacrylate copolymer, 2-ethylhexyl acrylate/methyl methacrylate/butyl methacrylate copolymer, and the like. These may be used alone or in combination of two or more.

The antioxidant is not particularly limited, and examples thereof include phenolic antioxidants. These may be used alone or in combination of two or more.

The light stabilizer is not particularly limited, and examples thereof include salicylic acid ester-based, benzophenone-based, benzotriazole-based, cyanoacrylate-based ultraviolet absorbers, and hindered amine-based light stabilizers. These may be used alone or in combination of two or more.

It is not particularly limited, and examples include organic pigments such as azo-based, phthalocyanine-based, threne-based, and dye lake-based pigments, and inorganic pigments such as oxide-based, molybdenum chromate-based, sulfide/selenide-based, and ferrocyanide-based pigments. mentioned. These may be used alone or in combination of two or more.

In the present invention, (B) nepheline cyanite is included as an essential component as a filler, but other conventional fillers may be included as long as the effects of the present invention are not impaired, such as calcium carbonate, Talc and the like may be included.

The vinyl chloride resin composition according to the present invention is prepared by mixing the above component (A), the above component (B) and optional components as desired with any melt kneader (e.g., single screw extruder, twin screw extruder, It can be obtained by melt-kneading using rolls, mixers, various kneaders, etc.). The resulting vinyl chloride resin composition (compound) has a coefficient of linear expansion of less than 5×10 ⁻⁵ /° C. and excellent dimensional stability, so it can be suitably used for building materials such as sashes as described later. can be done. In the present invention, the coefficient of linear expansion is measured in accordance with JIS K 7197 (testing method for coefficient of linear expansion of plastics) under the measurement conditions of a temperature range of 0 to 50°C and a heating rate of 5°C/min. value.

<Molded product>
A desired molding can be obtained from the vinyl chloride resin composition according to the present invention. The method for obtaining the molded product is not particularly limited, and conventionally known methods such as extrusion molding, injection molding, calender molding, and press molding can be applied. In particular, it is preferable to obtain a molded article by an extrusion molding method. Among extrusion molding methods, profile extrusion molding methods for obtaining molded products such as resin sashes and window frames that require high designability require high molding temperatures, but the vinyl chloride resin of the present invention According to the composition, a molded article having a low linear expansion coefficient, excellent impact resistance, a smooth surface and no rough surface can be obtained.

Embodiments of the present invention will now be specifically described with reference to the following examples, but the present invention is not limited to these examples.

In this specification, the coefficient of linear expansion, Charpy impact strength, workability, and appearance were evaluated by the following methods.

<Linear expansion coefficient>
In accordance with JIS K 7197 (testing method for coefficient of linear expansion of plastics), a tape-shaped extrudate having a thickness of 4 mm was measured under the measurement conditions of a temperature range of 0 to 50°C and a heating rate of 5°C/min.

<Charpy impact strength>
According to JIS K 7111, a tape-shaped extrudate having a thickness of 4 mm was provided with a notch of 2 mm to prepare a sample, and the Charpy impact strength at 23° C. was measured.

<Processability (at the time of compound molding)>
The following raw materials are mixed according to the composition shown in Table 1, and compound molding is performed using a PLASTIC EXTRUDER (manufactured by Nakatani Kikai Co., Ltd., screw diameter 20 mm) at a screw temperature of 150 to 170 ° C. and a die temperature of 180 ° C. Extrusion load. (A) was measured.

<Processability (at the time of extrusion molding)>
Using the compound composition obtained by the above compound molding, a kneading/extrusion molding evaluation test device (Laboplastomill manufactured by Toyo Seiki Co., Ltd. 30 ml) was used with a preheating time of 2 minutes, a test temperature of 170 ° C., and a test rotation speed of 30 rpm. The gelling time and the torque load (N·m) when kneading were measured.

<Appearance>
The appearance of the tape-shaped extrudate having a thickness of 4 mm was visually observed and evaluated according to the following criteria.
◯: The surface of the molding is smooth and no rough surface is observed.
Δ: Slight roughness is observed on the surface of the molded product.
x: Rough surface is observed on the surface of the molding.

The materials used are as follows.

Component (A)
TK-1000 (polyvinyl chloride, average degree of polymerization 1000, Shin-Etsu Chemical Co., Ltd.)
Component (B)
(B-1): Nesper (nepheline cyanite particles, particle size D ₅₀ =5.2 μm, D ₉₀ =11.8 μm, aspect ratio 1, manufactured by Toyo Fine Chemical Co., Ltd.)
(B-2): KK600 (calcium bicarbonate particles, particle diameter D ₅₀ =4.0 μm, aspect ratio 1, manufactured by Shimizu Corporation)
(B-3): MS-Z (talc particles, particle diameter D ₅₀ = 15 μm, aspect ratio 8, manufactured by Nippon Talc Co., Ltd.)
(B-4): AB-25S (muscovite, particle size D ₅₀ =24 μm, aspect ratio 80, manufactured by Yamaguchi Mica Kogyo Co., Ltd.)
Other ingredients
RX-210 (Ca/Zn-based stabilizer, ADEKA STAB RX-210, manufactured by ADEKA Co., Ltd.)

The above raw materials were mixed according to the composition shown in Table 1, and the resin composition was temporarily kneaded under the conditions of a die outlet resin temperature of 180 ° C. using a single screw extruder and a flat plate die, and a width of 20 mm and a thickness Extrusion molding was performed so as to obtain a tape shape of 4 mm to obtain a molding. The linear expansion coefficient, Charpy impact strength, and appearance were evaluated for the obtained moldings. The evaluation results were as shown in Table 1.

As is clear from the evaluation results in Table 1, the vinyl chloride resin composition containing no filler (Example 4) has good impact resistance and processability, but has a linear expansion coefficient of 7.8 × 10. It is as large as ^-5 /°C. Further, in vinyl chloride resin compositions (Examples 6 to 8) to which conventional fillers are added, although the coefficient of linear expansion and impact resistance can be compatible to some extent, the processability is insufficient, especially talc (example 7) and those using mica (Example 8) have a rough appearance. On the other hand, the vinyl chloride resin compositions containing a specific amount of nepheline cyanite (Examples 2 and 3) had a low coefficient of linear expansion, excellent impact resistance, smooth surface and no rough surface. I know you can get it.

Claims (6)

(A) a vinyl chloride resin;
(B) nepheline cyanite;
comprising
The (B) nepheline cyanite has a particle shape with an aspect ratio of 2 or less, and is contained in an amount of 5 to 40 parts by mass with respect to 100 parts by mass of the vinyl chloride resin (A),
A vinyl chloride resin composition characterized by having a coefficient of linear expansion of less than 5×10 ⁻⁵ /°C. The nepheline cyanite (B) is particles having a cumulative frequency of 50% (D ₅₀ ) of 3 to 10 μm in a number-based cumulative frequency distribution curve measured using a laser diffraction/scattering particle size distribution analyzer. The vinyl chloride resin composition according to claim 1, which has a diameter. A molded article made of the vinyl chloride resin composition according to claim 1 or 2. 4. A molding according to claim 3, obtained by extrusion. 5. The molding according to claim 3 or 4, which is used as a building material. 6. Molding according to claim 5, wherein the building material is a sash.