JPH10292080A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vinyl chloride resin compsn. which has a low linear thermal expansion coefficient, a high impact strength, a good moldability, and an excellent molded appearance such as smoothness. SOLUTION: This compsn. is prepd. by compounding 100 pts.wt. vinyl chloride resin with 5-100 pts.wt. inorg. fibrous filler (pref. wollastonite and/or aluminum borate fibers) having an average diameter of 0.5-10 μm and an aspect ratio of 3-18 and 1-20 pts.wt. polymer modifier (for a vinyl chloride resin) at least partly comprising chlorinated polyethylene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for dispersing a fibrous inorganic filler having a specific fiber diameter and an aspect ratio in a vinyl chloride resin uniformly, and using a chlorinated polyethylene alone or with another impact-resistant reinforcing agent. The present invention relates to a vinyl chloride resin composition capable of providing a molded article having a small expansion and contraction with respect to a temperature change and excellent appearance and physical properties when used together.

[0002]

2. Description of the Related Art In recent years, attempts have been made to improve the mechanical strength and the dimensional stability against thermal changes by combining a rigid vinyl chloride resin with an inorganic filler.

[0003] Japanese Patent Application Laid-Open No. 60-173037 discloses that 100 to 100 parts by weight of a vinyl chloride resin has a length of 0.05 to 3 m.
5 to 30 parts by weight of short glass fiber of
To 50 parts by weight and at least one selected from chlorinated polyethylene, ethylene-vinyl acetate copolymer, acrylonitrile-butadiene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer and acrylic resin It describes a vinyl chloride resin molded product in which 5 to 20 parts by weight of a modifier are dispersed.

Japanese Patent Publication No. 61-44105 discloses that
(A) a polyvinyl chloride resin, (B) a polyamide having a glass transition point in the range of about -30 ° C to about 15 ° C, modified by grafting acrylic acid or methacrylic acid, or modified by binding phenol. A composite composition comprising a modified polyamide and (C) a staple or lamellar filler is described.

Japanese Patent Publication No. 6-6671 discloses that at least one of 30 to 99 selected from the group consisting of vinyl chloride resins, polystyrene resins, polyamide resins, thermoplastic polyester resins and polyphenylene sulfide resins.
% By weight, an average fiber diameter of 0.1 to 2 μm, an aspect ratio of 20 to 100, and 70 to 1% by weight of a fibrous inorganic filler selected from the group consisting of magnesium hydroxide fibers and magnesium oxide fibers. % Of a thermoplastic resin composition.

[0006]

However, in the case of mixing a hard vinyl chloride resin with short glass fibers, or in the case of mixing a thin plate-like inorganic filler such as mica or talc,
Although the mechanical strength can be increased and the coefficient of linear expansion can be reduced, the impact strength is low and not practical.

When the shape characteristics of the inorganic filler are taken into consideration, the effect of dimensional stabilization against heat change is insufficient with a particulate inorganic filler having a small shape factor. 100 granular inorganic filler
If a large amount of filler is used, which exceeds the weight part, not only the molding processability is poor, but also the impact strength is significantly reduced.

Further, a fibrous inorganic filler having a large average fiber diameter and a long length, for example, a fiber diameter of 10 μm and a length of 30 μm.
For commercially available glass fibers such as over 0 μm,
Due to the large particle size of the filler, the surface of the extruded hard vinyl chloride is rough, the appearance is poor in extrusion molding, and the impact resistance is too low, which is not practical. on the other hand,
A fibrous inorganic filler having a small aspect ratio is similar to a granular filler, and has insufficient dimensional stability against heat change.

The inventor of the present invention has conducted intensive studies to solve the above problems, and as a result, by controlling the fiber diameter and aspect ratio of the fibrous inorganic filler within a specific range, the impact strength is less reduced and the rigidity is reduced. Was improved, and the coefficient of linear expansion could be effectively reduced.

That is, an object of the present invention is to provide a vinyl chloride resin composition having a combination of excellent appearance of a molded article such as a small coefficient of linear expansion, excellent impact strength, excellent moldability and smoothness. is there.

[0011]

According to the present invention, an average fiber diameter is 0.5 to 100 parts by weight of a vinyl chloride resin.
5 to 100 parts by weight of a fibrous inorganic filler having an aspect ratio of 3 to 18, preferably 5 to 15 μm, preferably 1 to 6 μm, and at least a part thereof is a chlorinated polyethylene for a vinyl chloride resin. Polymer modifier 1
There is provided a vinyl chloride resin composition characterized by comprising 20 parts by weight.

[0012]

DETAILED DESCRIPTION OF THE INVENTION

[Function] In the present invention, among the fibrous inorganic fillers, a fibrous inorganic filler having an average fiber diameter and an aspect ratio in a specific range is selected, and this is converted into a chlorinated polyethylene, at least a part of which is chlorinated polyethylene. It is characterized by being combined with a vinyl chloride resin in combination with a polymer modifier for vinyl resin.

Inorganic short fibers generally used for reinforcing thermoplastic resins such as vinyl chloride resins have a large aspect ratio of 20 to 100. Even if satisfactory for the purpose of keeping the coefficient of expansion at a low value, the moldability, especially the thin-wall moldability, is reduced, the impact resistance is remarkably reduced, and the appearance characteristics of the molded product, especially, the surface smoothness is deteriorated. That is the drawback.

In the present invention, by using a fibrous inorganic filler having an average fiber diameter and an aspect ratio in a specific range, as shown in an example described later, the moldability, particularly the linear expansion coefficient, is suppressed to a low value. It is possible to improve thin-wall moldability, remarkably improve impact resistance, and also improve appearance characteristics of a molded product, particularly, surface smoothness.

Considering the reinforcing effect of the fibrous inorganic filler by the fibrous inorganic filler, it is considered that the dispersion state of the fibrous inorganic filler in the vinyl chloride resin and its aggregation form have an important influence. . When the average fiber diameter of the fibrous inorganic filler is less than 0.5 μm or when the aspect ratio is more than 18, the fibrous filler becomes bulky, and is not only dry-blended but also melt-blended into vinyl chloride resin. Dispersion becomes worse. This makes molding processability unstable,
It is considered that the impact resistance is also reduced. On the other hand, when the average particle size is more than 10 μm or the aspect ratio is less than 3, even if there is no problem in dispersing in the resin, it becomes difficult to form a reinforcing structure by aggregation of the filler particles, which is also a problem in resistance. The impact strength is reduced and the linear expansion coefficient cannot be reduced.

According to the present invention, it has been found that a range satisfying both the improvement of impact resistance and the reduction of the coefficient of linear expansion exists in a range lower than the aspect ratio which has been conventionally considered to be appropriate. It is.

In the present invention, a fibrous inorganic filler having an average fiber diameter and an aspect ratio in a specific range is used, and a polymer modifier for a vinyl chloride resin, at least a part of which is chlorinated polyethylene, is used in combination. It is also very important to do so. That is, when the fibrous inorganic filler specified in the present invention is solely incorporated into the vinyl chloride resin, it is difficult to improve the impact resistance, but the polymer modifier for the vinyl chloride resin is difficult to improve. At the same time, it is possible to improve the impact resistance, and also improve the moldability and the appearance characteristics of the molded product.

The reason is considered as follows.
That is, the polymer modifier for vinyl chloride resin is a linear polymer having an appropriate polar group, and is considered to have a binder effect (can contain a large amount of inorganic substances), so that the surface of the fibrous inorganic filler can be coated. It is thought to improve dispersibility and adhesion in vinyl chloride resin, and furthermore, chlorinated polyethylene is said to have a high damping effect,
This is thought to have led to improvements in impact resistance and workability.

[Vinyl Chloride Resin Composition] In the present invention, a vinyl chloride copolymer is used as the vinyl chloride resin in addition to a straight polymer (homopolymer) of vinyl chloride. Vinyl-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, vinyl chloride-styrene copolymer, vinyl chloride-isobutylene copolymer, vinyl chloride-vinylidene chloride copolymer, chloride Vinyl-styrene-maleic anhydride terpolymer, vinyl chloride-styrene-acrylonitrile copolymer, vinyl chloride-butadiene copolymer, vinyl chloride-propylene copolymer, vinyl chloride-vinylidene chloride-vinyl acetate terpolymer Polymer, vinyl chloride-acrylate copolymer, vinyl chloride-maleate copolymer Copolymer, vinyl chloride-methacrylic acid ester copolymer, vinyl chloride-acrylonitrile copolymer, polymers such as internally plasticized polyvinyl chloride, and these chlorine-containing polymers and polyethylene, polypropylene, polybutene, poly-3-methylbutene Polyolefins such as α-olefin polymers or ethylene-vinyl acetate copolymers, ethylene-propylene copolymers and the like, and their copolymers, polystyrene, acrylic resins, styrene and other monomers (for example, maleic anhydride , Butadiene, acrylonitrile, etc.), acrylonitrile-butadiene-styrene copolymer, acrylate-butadiene-styrene copolymer, blended products with methacrylate-butadiene-styrene copolymer, and the like. Can be. Among these, polyvinyl chloride (PVC), chlorinated polyvinyl chloride (chlorinated PV)
C), ethylene-vinyl acetate-vinyl chloride graft copolymer (EVA graft PVC) and acryl-vinyl chloride graft copolymer (acryl graft PVC) are preferred, and those having an average degree of polymerization of 700 to 1400 are preferably used. Is done.

Examples of the fibrous inorganic filler used in the present invention include wollastonite, carbon fiber, alumina fiber, boron fiber, zonotolite, gypsum fiber, PMF processed mineral fiber, glass fiber and the like. Calcium carbonate, silicon carbide, silicon nitride, potassium titanate, aluminum borate, basic magnesium sulfate, which are commercially available as single crystal structural fibers (whiskers),
Zinc oxide, titanium oxide, magnesium oxide, graphite, magnesium hydroxide, and the like can be used. Of course, these fibers must satisfy the above-mentioned average fiber diameter and aspect ratio. One of the important factors for realizing the effect of the present invention is that the average particle diameter of the fibrous inorganic filler is 0.5 to 10 μm, preferably 1 to 6 μm.
μm and the aspect ratio is 3 to 18, preferably 5 to 15.

The fibrous inorganic filler to be used is selected from silane, titanate, aluminum, zirconium and other coupling agents in order to enhance the fiber opening effect and dispersibility in resin according to the filler. The surface may be treated with a surface treating agent such as a fatty acid, acrylic acid, or wax. These may be used alone or in combination of two or more.

The vinyl chloride resin composition of the present invention has an average fiber diameter of 0.5 to 10 μm and an aspect ratio of 3 to 1.
By adding 5 to 100 parts by weight of the fibrous inorganic filler of No. 8, it is possible to improve the dimensional stability against heat change of the molded product and to increase the rigidity without deteriorating the moldability and impact resistance. Can be. If the fibrous inorganic filler is added in a small amount of less than 5 parts by weight based on 100 parts by weight of the vinyl chloride resin, a sufficient effect cannot be expected, and a large amount exceeding 100 parts by weight is added. In such a case, the moldability deteriorates and the impact resistance also decreases.

The thermoplastic resin composition may further contain a non-fibrous filler in addition to the fibrous inorganic filler having specific shape characteristics. If the amount of the non-fibrous filler is more than 20 times, the impact resistance is remarkably reduced, so that a smaller amount should be used.

Examples of the non-fibrous filler include granular fillers such as calcium carbonate, titanium oxide, glass beads, and wood flour, and plate-like fillers such as mica, talc, kaolinite, montmorillonite, graphite, and pulp chips. No.

The polymer modifier for vinyl chloride resin is at least partially composed of chlorinated polyethylene,
In addition, ethylene-vinyl acetate copolymer (EVA), acrylonitrile-butadiene-styrene copolymer (AB
S), methyl methacrylate-butadiene-styrene copolymer (MBS), styrene-butadiene-styrene block copolymer (SBS) and acrylic resin
Species or a combination of two or more species can be mentioned.

Among these modifiers, chlorinated polyethylene is particularly preferred, and by adding it to the compounding system, the impact strength and tensile elongation characteristics of the molded article can be significantly improved. . The chlorine content of the chlorinated polyethylene is preferably in the range of 20 to 45% by weight, especially 30 to 40% by weight. Furthermore, EVA, ABS, MB
Other modifiers such as S, NBR, SBS and acrylic resin may be used in combination.

The vinyl chloride resin composition of the present invention comprises, in addition to other components, a polymer modifier for vinyl chloride resin containing chlorinated polyethylene as an essential component.
By adding 1 to 20 parts by weight with respect to parts by weight, the impact resistance of the molded article is improved without lowering the dimensional stability against heat change. No effective impact modification is observed when only a small amount of chlorinated polyethylene is added in an amount of less than 1 part by weight, and the coefficient of thermal expansion becomes too large when added in a large amount exceeding 20 parts by weight. Tend.

In the composition of the present invention, in addition to the above components, additives known per se such as heat stabilizers, processing aids, coloring agents, foaming agents, ultraviolet absorbers, antistatic agents, etc. It can be blended according to a known formulation.

The molding method of the composition of the present invention is not particularly limited, and is a vinyl chloride resin, a fibrous inorganic filler having a specific average fiber diameter and a specific aspect ratio, and a polymer-modified polymer for vinyl chloride resin. Ingredients, if necessary, mixed with the other additives at a predetermined ratio, mixed with a super mixer or the like, and molded with a calender roll, a single-screw extruder, a twin-screw extruder, etc. to obtain a directly molded product. Can be. Further, from the above-described composition, pellets are produced by an orn roll, a Banbury mixer, a single screw extruder, a twin screw extruder, and the like, and this is molded by extrusion molding, injection molding, calendar molding, compression molding, or the like, and a molded product is formed. May be obtained.

The obtained molded article has good mechanical properties, excellent dimensional stability against heat change, and good surface properties. The vinyl chloride resin composition of the present invention can be used in the housing industry such as building materials and home appliances. It is very useful as an industrial material for the electric industry.

[0031]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Examples are shown in Table 1 and Comparative Examples are shown in Table 2.

(Examples 1 to 7, Comparative Examples 1 to 7) A vinyl chloride resin of the type and amount shown in Tables 1 and 2 and an inorganic filler and a modifier were mixed by a super mixer, Was used to directly produce a window frame molded product using a twin-screw extruder, and the characteristics of the items shown in Tables 1 and 2 were evaluated. The results are shown in Tables 1 and 2.

[Table 1]

[Table 2]

Regarding the coefficient of linear expansion, the window frame molded product was left in a hot air circulating drying oven at 70 ° C. for 12 hours, immediately after being taken out of the drying oven, and then the dimensional change when left at 23 ° C. room temperature for 24 hours. Asked from.

The elongation was measured according to JIS-A-5706.

Regarding the impact strength, JIS-K-7111
The Charpy impact strength was measured at 23 ° C.

As is clear from Table 1, Examples 1 to 7
In each case, since the coefficient of linear expansion was small, the dimensional change with respect to the heat change was small, and the physical properties such as impact resistance were improved rather than Comparative Example 1 in which the inorganic filler was not blended.
In addition, the moldability was able to be extruded into a thin irregular-shaped product having a thickness of 1.0 mm, and the extruded product was good in terms of surface properties and free from aggregation of inorganic fillers.

In the case of Comparative Example 1, the coefficient of linear expansion is remarkably large and easily deformed due to a change in temperature. Also, Comparative Examples 2 to
In the case of No. 7, physical properties such as impact resistance and elongation are low, which is not practical. Further, Comparative Examples 5 to 7 have no flat smoothness in extrusion molding, cannot perform thin-wall profile extrusion molding, and are not practical.

[0038]

By using the vinyl chloride resin composition of the present invention, it is possible to provide an extruded product having good molding properties, a small coefficient of linear expansion, high impact resistance and good appearance. .

Claims (3)

[Claims] 1. 5 to 100 parts by weight of a fibrous inorganic filler having an average fiber diameter of 0.5 to 10 μm and an aspect ratio of 3 to 18 with respect to 100 parts by weight of a vinyl chloride resin, and at least a part thereof. Is a chlorinated polyethylene, wherein 1 to 20 parts by weight of a polymer modifier for a vinyl chloride resin is blended. 2. The vinyl chloride resin composition according to claim 1, wherein the fibrous inorganic filler is wollastonite. 3. The vinyl chloride resin composition according to claim 1, wherein the fibrous inorganic filler is an aluminum borate fiber.