WO2000046307A1

WO2000046307A1 - Resin composition and molded object for light reflection

Info

Publication number: WO2000046307A1
Application number: PCT/JP2000/000624
Authority: WO
Inventors: Hiroshi Shibata; Yoichi Takahashi
Original assignee: Maruo Calcium Company Limited
Priority date: 1999-02-05
Filing date: 2000-02-04
Publication date: 2000-08-10
Also published as: JP4603694B2

Abstract

A resin composition characterized by being obtained by compounding a heat-resistant thermoplastic resin with a particulate filler and calcium carbonate whiskers having a major-axis length of 3 to 50 νm, a minor-axis length of 0.3 to 2.0 νm, and an aspect ratio (major-axis length/minor-axis length) of 5 to 50; and a molded object for light reflection comprising the resin composition. The molded object has high mechanical strength and is excellent in adhesion to metallic films and in surface smoothness. It is suitable especially for light reflection.

Description

Description Resin composition and molded article for light reflection

The present invention relates to a resin composition and a molded article for light reflection, and more particularly, to heat resistance, strength, impact resistance, stiffness, and dimensions by adding a whisker-like calcium carbonate to a heat-resistant thermoplastic resin. It is excellent in stability and moldability, and especially when it is used as a light reflecting molded article such as a lamp reflector used for automobile headlights, it can provide good adhesion and surface smoothness of a metal film. The present invention relates to a resin composition that can be used. Landscape technology

In recent years, the use of plastics for metal parts in the automotive industry has been increasing at a faster pace. The demands on plastic materials to be replaced are not limited to lighter weight and increased design freedom, but also reduce the production cost and the productivity of the plastic parts themselves due to the reduction of the number of parts due to the combination of parts. It is becoming more sophisticated. Among them, automotive lamp reflectors are relatively large parts, and there is a strong demand for weight reduction and cost reduction by improving productivity.

Conventionally, the conversion of a lamp reflector into a plastic has been mainly made of a resin composition based on a thermosetting resin such as a phenol resin or an unsaturated polyester.

However, although lamp-reflecting made of thermosetting resin can achieve the objectives of light weight and low material cost, the molding cycle is long, mold contamination occurs frequently, and cleaning is frequently required. To Contains. In addition, there is a problem in terms of productivity, such as the need for a step of removing burrs from the molded product, which is likely to occur. In addition, in recent years, molded products that can be recycled due to environmental problems Is desired, but it is difficult to meet this request.

Therefore, conversion of lamp reflex into a thermoplastic resin material is being studied. For example, fibrous fillers such as polyamide (nylon) resin, polyester resins such as polybutylene terephthalate (PBT) and polyethylene terephthalate (PET), and polyphenylene sulfide resin (PPS) Attempts have been made to impart heat resistance, mass reduction and surface smoothness by blending a non-woven filler and a hollow filler further.

Specifically, Japanese Patent Application Laid-Open No. 4-334480 discloses a composition in which a fibrous inorganic filler, a non-fibrous inorganic filler and a hollow hollow inorganic filler having a specific diameter are mixed with PPS. Has been proposed. Also, Japanese Patent Application Laid-Open No. Hei 4-2-279962 discloses a molding mixture comprising PPS, whiskers of an alkaline metal salt or an alkaline earth metal salt, and a mineral filler. A reflector molded using the same has been proposed.

Furthermore, Japanese Patent Application Laid-Open No. 7-188555 discloses a lamp resin formed by molding a resin composition comprising PPS, a whisker-like aluminum borate reinforcing material, and a non-fibrous inorganic filler. Japanese Patent Laid-Open Publication No. Hei 8-4-1131 discloses a reflector for light reflection formed by molding a resin composition comprising PPS having a specific melt viscosity, potassium titanate whiskers, and calcium oxide having a specific particle size. Japanese Patent Application Laid-Open Publication No. Hei 10-237373 discloses a resin composition for lamp reflector Yuichi, which comprises PPS, calcium carbonate having a specific particle diameter, and wollastite having a specific fiber diameter. Being p

As described above, the technologies proposed in the past have demonstrated heat resistance, dimensional stability, and strength by blending a woven filler with a relatively inexpensive heat-resistant resin. JP00 / 00

Insufficient heat resistance, strength and dimensional stability of granular fillers are reinforced with arrowhead fillers, and surface smoothness is not affected by the inherent smoothness of resin. However, in terms of weight reduction, it is fundamental to use hollow filler materials.

In addition, the physical properties required for the lamp preflector are that it is relatively inexpensive in addition to heat resistance, dimensional stability, surface smoothness, light weight and high strength. In addition, metallization of aluminum or the like is performed in a later process for the lamp reflex, and it is required to have an adhesive property to the metallized film and a metasmoothness (gloss). In terms of price, Japanese Patent Application Laid-Open No. Hei 10-237330 proposes to mix wollastite, which is a relatively inexpensive fiber-like substance.

However, in any of the above methods, even if the physical properties are satisfied, a very expensive whisker is used, so that an increase in product cost is unavoidable and is not suitable for practical use. In addition, it is difficult to say that satisfactory physical properties are obtained when a relatively inexpensive wollastonite is used. The present invention is excellent in moldability, heat resistance, strength, rigidity, dimensional stability, adhesiveness to metal vapor deposition film and surface smoothness, especially for light reflection molding such as automotive lamp reflector It is intended to provide a resin composition suitable for a body and a molded article for light reflection obtained by molding the resin composition at low cost.

The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, a resin composition obtained by blending a heat-resistant thermoplastic resin with a powder having a specific particle diameter and a specific carbonic acid-containing calcium carbonate is desired. Have been found to be sufficiently satisfied, and the present invention has been reached. Disclosure of the invention

That is, the first aspect of the present invention is to provide a heat-resistant thermoplastic resin with a granular filler and a long diameter. It is characterized by the fact that whisker-like calcium carbonate with a ratio of 3 to 50 / m and a short length of 0.3 to 2.0 <m and an aspect ratio (major axis / minor axis) of 5 to 50 is blended. It contains a fat composition.

As a preferable glue, the mixing amount of whisker-like calcium carbonate is 5 to 50% by weight.

In a preferred embodiment, the calcium carbonate carbonate has a BET specific surface area of 1 to 1

It is.

In a preferred embodiment, the surface-treated calcium carbonate is treated with at least one selected from the group consisting of a silicone-based surface treatment agent, a titanate-based surface treatment agent, a carboxylic acid-based surface treatment agent, and a sulfonic acid-based surface treatment agent. It is a thing.

In a preferred embodiment, the particulate filler is fine calcium carbonate. In a preferred embodiment, the amount of the particulate filler is 10 to 80% by weight.

In a preferred embodiment, -wollastonite is further blended. In a preferred embodiment, the heat-resistant thermoplastic resin is a polyarylene sulfide resin.

A second aspect of the present invention includes a light-reflective molded article obtained by molding a resin composition.

In a preferred embodiment, the molded article for light reflection is a lamp reflector.

BEST MODE FOR CARRYING OUT THE INVENTION

Regarding the particle size of the whisker-like calcium carbonate used in the present invention, the major axis is 3 to 50 / zm, the minor axis is 0.3 to 2.0 m, and The cut ratio (major axis or short diameter) is 5 to 50. Preferably the major axis is 5 ^ 40 m, more preferably 1 C! 330 / zm, and the length of the short stomach is 0.25 to 2.0 m, more preferably 0.5 to 1.6 m. If the major axis is less than 3 μπι or the minor axis is less than 0.3 / m, not only does the resin pressure rise and workability deteriorates, but also the surface smoothness is impaired. If the major axis exceeds 5 Owm or the minor axis exceeds 2.0 m, the surface smoothness is impaired.

If the calcium carbonate calcium carbonate has an aspect ratio (major axis Z minor axis) of less than 5, heat resistance is insufficient, and if it exceeds 50, warpage occurs.

The diameter of the whisker-like carbonic acid lumps is determined by electron microscopy. Such a whisker-like calcium carbonate can be easily prepared, for example, by a method described in Japanese Patent Application Laid-Open No. 3-88871, Japanese Patent Application Laid-Open No. 4-21515, and the like. Manufacturable.

The BET ratio ¾ area of the whisker-like calcium carbonate used in the present invention is preferably 1 to 15 m ² Zg, more preferably 3 to 1 m ² Zg.

It is preferably 4 to 1 Om ² / g. When the BET specific surface area is larger than 15 m ² Z, the workability is deteriorated due to the increase of the resin pressure, and the surface smoothness tends to be deteriorated. If the BET specific surface area is smaller than lm ² /, it is difficult to obtain surface smoothness. The BET specific surface area is determined by a nitrogen adsorption method. When mixing the whisker-like calcium carbonate, considering the workability, it is preferable that the powder of calcium whisker-like calcium powder is low, and the method of reducing the bulk of the powder can be achieved by granulation or surface treatment. is there. The bulk of the powder is not more than 20. OmlZg, more preferably not more than 15. OmlZg, and still more preferably not more than 10. OmlZg. The powder bulk is JI

It is measured by the apparent specific volume (static method) of the SK 5101 pigment test method. The whisker-like calcium carbonate used in the present invention includes a silicone-based surface treatment agent, a titanate-based surface treatment agent, a carboxylic acid-based surface treatment agent, and a sulfo-based surface treatment agent. It is preferable to perform surface treatment with an acid-based surface treatment agent or the like. These surface treatment agents can be used alone or in combination of two or more. More preferably, the surface treatment is performed with a silicone-based surface treatment agent or a titanate-based surface treatment agent.

The silicone-based surface treating agent is a compound having a reactive silyl group in the molecule and a silicate or polysilicate such as silicon oil or silicon emulsion.

For example, silane coupling agents are organic silicon monomers having two or more different reactive groups, specifically, vinyl silane, acrylic (methacrylic) silane, epoxy silane, amino silane, mercapto, chlorop This is a pill-based silane cutting agent.

Monomers and partial condensates (tetraalkoxy silicates) having a reactive group of one spikelet include methyl silicate, ethyl silicate, α-pyr silicate, isopropyl silicate, butyl ligate, and isobutyl silicate. Monomer and partial condensate.

The titanate-based surface treatment agent is represented by the following structural formula.

(ΧΟ) „T i (OR) 4-„

XO: R 'COO, (R "0) 2 P (0) 0, etc.

RO: Lower alkoxy group

n: 1-3

One of the carboxylic acid-based surface treatment agents consists of a polymer of α, an unsaturated carboxylic acid monomer, and a partially or completely neutralized product thereof with an alkali salt, an aluminum salt, and an amine. It is a type, and preferably contains a hydroxyl group and a carboxyl group, which are obtained by copolymerizing a 3 unsaturated carboxylic acid and a 3 unsaturated carboxylic acid hydroxyester. The other is a fatty acid-based treating agent, which is a higher fatty acid of saturated or unsaturated fatty acids. Metal salts such as fatty acids or alkali metals, alkaline earth metal salts, ammonium salts, esters, zinc, and iron can be used.

Sulfonic acid-based surface treatments include: alkyl ether sulfate, alkyl ether sulfate, alkyl sulfate, alkyl aryl sulfate, alkyl amide sulfate, alkyl sulfonic acid, alkyl naphthylene sulfonic acid, monoolefin sulfonic acid, N— Sulfonic acid, verfluoroalkylsulfonic acid, alkylbenzenesulfonic acid and the like. The treatment amount of the surface treating agent is usually 0.1 to 5% by weight, preferably 0.2 to 3.0% by weight, more preferably 0.5 to 2.0% by weight. When the amount of surface treatment is less than 0.1%, the surface treatment effect is not sufficiently exhibited. When the amount is more than 5% by weight, the lamp may be undesirably exposed.

The surface treatment of the whiskers-like calcium carbonate with the surface treatment agent used in the present invention can be performed by any of a wet method and a dry method. In the case of wet surface treatment, a surface treatment agent may be added to the whisker-like calcium carbonate water or dissolved slurry, and in the case of dry surface treatment, powder such as a helical mixer or ribbon mixer may be stirred. Anonymity can be used.

Examples of the heat-resistant thermoplastic resin used in the present invention include polyester resin such as polyamide, polybutylene terephthalate (PBT) and polyethylene terephthalate (PET), polyarylene sulfide resin (PAS), and polyphenylene sulfide. Resin (PPS), polyphenylene ether, polyimide, polyether sulfone, polycarbonate, ABS, polyacetal, polyether ketone, and syndiotactic polystyrene (SPS). It can be used in combination of more than one species. Among these resins, heat resistance, workability, cost and From the balance of physical properties, PAS, PPS, and SPS are preferred.

PAS is PPS having a repeating unit represented by a typical structural formula 1 (Ph—S—) 1 (where Ph is a phenyl group) of 70% or more. Polyylene sulfide is generally known to have a molecular structure having substantially no linearly branched or crosslinked structure and a structure having a branched or crosslinked structure depending on its production method. This type is also effective, and may be a copolymer or a mixture of both. The amount of the heat-resistant thermoplastic resin is preferably 15 to 85% by weight, more preferably 25 to 65% by weight, and still more preferably 35 to 55% by weight. If it is less than 15% by weight, the impact strength is reduced, while if it exceeds 85% by weight, the strength becomes insufficient and the heat resistance becomes insufficient.

The mixing halo of the calcium carbonate is preferably 5 to 50% by weight, more preferably 5 to 30% by weight, and even more preferably 7 to 20% by weight. If the amount is less than 5% by weight, heat resistance and strength are insufficient. If the amount is more than 50% by weight, workability deteriorates due to an increase in resin pressure and the surface becomes flat. Worse.

Examples of the particulate filler used in the present invention include silicates such as alumina silicate, clay alumina, gay oxide, magnesium oxide, zirconium oxide, titanium oxide, iron oxide, calcium carbonate, magnesium carbonate, dolomite, and sulfuric acid. Examples thereof include calcium, barium sulfate, glass beads, ceramic beads, and calcium phosphate, and these can be used alone or in combination of two or more. In particular, calcium carbonate is preferred in terms of particle size control and compatibility with the resin.

Calcium carbonate includes calcium carbonate obtained by chemically reacting calcium carbonate and heavy calcium carbonate obtained by mechanically pulverizing and classifying.Either of them can be used. Finely pulverize the latter Fine ground calcium carbonate is preferred. There are dry and wet production methods for fine powdered calcium carbonate.

The blending amount of the granular filler is 10 to 80% by weight, preferably 30 to 60% by weight, and more preferably 40 to 55% by weight. 10 fold ;! : If it is less than%, the heat resistance cannot be satisfied, and if it exceeds 80% by weight, the workability may be deteriorated due to an increase in resin pressure.

Since the particle size of the fine powdered calcium carbonate is indefinite, it is common to use the particle size calculated from the specific surface area (air permeation type). (6 X 104) / 2.7 X ratio Calculated by surface area. For example, the particle diameter effective as a lamp reflector is 2 / zm or less, more preferably 1 or less, and further preferably 1 ^ πι or less. When the average particle size is larger than 2 m, the surface smoothness may be deteriorated. Further, the value of coarse particles of 10 or more measured by a laser particle size distribution analyzer (Microtrac FRA) is preferably 5% or less, more preferably 0%. More preferably, coarse particles of 5 m or more are 0%. When the amount of coarse particles of 10 / in or more is more than 5%, the surface smoothness may be deteriorated.

Other heat-resistant and dimensional stability reinforcing agents other than calcium carbonate, such as glass fiber, titanic acid, Riwis, aluminum borate, aluminum oxide, titanium oxide, rock wool, stone oxide, etc. Power that can be used in combination with wollastonite, apatite whisker, etc. In particular, including cost performance, Xixi Iskar and wollastonite are preferable, and wollastonite is particularly preferable. By using these whisker-like fillers containing Ca as a main component, the metal adhesion and plating property of a molded product such as a lamp reflector are improved.

As for stone power, the major axis is about 50 to 60 m and the minor axis is about 2 m Commercially available stone iskers can be used. Wollastonite has a major axis of 20 to 50 zrn and a minor axis of 0. ~ 5 m can be used. The content of these is preferably 5 to 30% by weight. If it is less than 5% by weight, the effect of addition is not sufficient, and if it exceeds 30% by weight, the surface smoothness may be deteriorated.

Other additives to be blended in the present invention include ordinary additives such as a release agent, an antioxidant, a heat stabilizer, a lubricant, and a crystal nucleating agent and a small amount within a range not to impair the effects of the present invention. Can be added. It is also possible to add plate-shaped sericite, kaolin, myriki, talc, and bentonite. There is no problem in using a hollow filler for weight reduction.

The method for preparing the resin composition used in the present invention is not particularly limited. For example, the mixture of the raw materials is melt-mixed in a single-screw or twin-screw extruder, a Banbury mixer, a mixer, a mixing roll, or the like. It is possible to supply and knead. There is no particular limitation on the mixing order of the raw materials, and the heat-resistant thermoplastic resin, the granular filler, the whisker-like calcium carbonate, and other fillers are dry-blended if necessary, and then melt-kneaded by the above-described method. Or a method of dry-blending a heat-resistant thermoplastic resin and a granular filler and then side-feeding whisker-like calcium carbonate, etc. It is preferable to disperse the pongee.

The degree of kneading of the filler is relatively strong, and favorable smoothness can be obtained by kneading with a shear. It is preferable to knead the mixture so that the aspect ratio of the whisker-like calcium carbonate is 10 or less, more preferably about 8 or less. If they are mixed together, heat resistance and strength tend to be insufficient. Follow It is desirable that the whisker-like calcium carbonate is kneaded with a shield such that the aspect ratio becomes 10 to 3. The analysis of the filler in the resin can be confirmed by baking at 500 ° C. for 2 hours and removing the resin component.

The resin composition thus obtained is formed into a light reflecting molded article such as a lamp reflector by injection molding or the like. For example, the resin composition is injection-molded using an injection molding machine having a sufficient capacity and a mold clamp, and the surface of the obtained molded body is subjected to a method such as vacuum deposition or plating (chemical plating, electric plating). In addition, a metal coating such as aluminum or zinc is applied to obtain a light reflecting molded article such as a lamp reflex. In the case of metal coating, it is also possible to previously prime the surface of the molded body.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but these do not limit the scope of the present invention in any way.

In the following description, “parts” and “%” represent “parts by weight” and “% by weight”.

(A) Pescar-like calcium carbonate

(1) Preparation of calcium carbonate iscar (without surface treatment) a to e As shown in Table 1, whisker-like carbonated calcium aes with different particle diameters a to e were prepared.

【table 1】

(2) Surface-treated whisker-like calcium carbonate f

Whisker-like calcium carbonate a shown in Table 1 (whisker A, manufactured by Maruo Calcium Co., Ltd.) After spraying a 1% aqueous slurry of calcium carbonate a (KBM-1003 vinyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.) as a 20% by weight water slurry onto whisker-like carbon dioxide, 100 ° C For 1 hour to obtain calcium f (powder bulk: 5 ml Zg).

) 2 (B) Preparation of fine powdered heavy calcium carbonate g- 〖

As shown in Table 2, three types of fine powdered heavy calcium carbonate g to i having different particle sizes were prepared.

[Table 2]

(C) Wollastonite j

Partek product name: Wickroll〗 0 (major axis / minor axis = 8 minor axis 4.3 m) ¾: Prepared.

Examples 1 to 4, Comparative Examples 1 and 2

PPS resin (melt viscosity: 190,000 Boys, manufactured by Tosoh 'Sastile Co., Ltd.) 40% by weight, fine powdered heavy calcium carbonate h45 weight, whisker-like calcium carbonate _{a to} e with different particle size and surface The treated whisker-like calcium carbonate f was blended at 15% by weight, then melt-kneaded at 32 n ° C using a twin screw extruder, and pelletized. Then, a flat molded product is obtained by an injection molding machine, and the tensile strength, bending strength and impact strength are measured by the following method did. Further, a flat molded product was subjected to aluminum vapor deposition by a vacuum vapor deposition method, and the adhesive strength and glossiness of the metal film were defined by the following method.

Table 3 shows the results.

[Table 3]

Tensile strength: ASTM D 6 3 8

Bending strength 2 ASTM D 7 9 0

Impact strength: AS TM D 2 5 6

Adhesive strength of metal film:

In a flat molded product on which aluminum was vapor-deposited, scratches were made on the aluminum vapor-deposited film of 100 squares at intervals of 1 mm using a cutter knife, and the aluminum vapor-deposited film was divided into a total of 100 square grids. Classified. A cellophane tape was stuck on this surface, and the aluminum vapor remaining on the flat molded product when it was peeled off.

1 The number of compartments for film deposition was counted and evaluated on a 4-point scale according to the following criteria.

◎: The number of remaining aluminum deposited film sections is 90 or more

〇: The number of sections of the remaining aluminum deposited film is 70 or more and less than 90 △: The number of sections of the remaining aluminum deposited film is 50 or more and less than 70 X: The number of sections of the remaining aluminum deposited film is 5 Less than 0

Metal film gloss (surface smoothness):

The glossiness of the aluminum vapor-deposited film was measured according to JISK 7105 (1981), and evaluated in four steps according to the following criteria.

：: Gloss degree of 120 or more

〇: Gloss 1 1 1 or more and less than 1 20

Δ: Gloss of 100 or more and less than 110

X: glossiness 100 droplets

Examples 5 to 7, Comparative Example 3

The same operation as in Examples 1 to 4 and Comparative Examples 1 and 2 was carried out, except that the blending amounts of the whisker illuminated calcium carbonate and the fine powdered heavy calcium carbonate h were changed as shown in 4. Table 4 shows the results. Example 1 is also shown for comparison.

[Table 4]

Examples 8, 9

The operations were performed in the same manner as in Examples 1 to 4 and Comparative Example 2 except that the type of the fine powdered calcium carbonate was changed as shown in Table 5. Table 5 shows the results. Example 1 is also shown for comparison.

[Table 5]

Examples 10 to 12, Comparative Example 4

The operation was performed in the same manner as in Example 14, Comparative Examples 1 and 2, except that wollastonite was added as shown in Table 6. Table 6 shows the results.

[Table 6]

From the results of Tables 1 to 6 above, the present invention uses calcium carbonate as a whisker, and is inexpensive, has good compatibility with resin, and further uses calcium carbonate as a filler. It is considered that the compatibility between the fillers is good, and not only the mechanical strength but also the adhesion to the metal film and the surface smoothness (the glossiness of the gold film) have been improved.上の Business availability

The resin composition of the present invention has good moldability, and is excellent in heat resistance, strength, impact resistance, rigidity, and dimensional stability, and has excellent adhesiveness of metal film and excellent surface smoothness for light reflection. A compact can be provided at low cost.

Claims

The scope of the claims

1. Heat-resistant thermoplastic resin with granular filler and major axis 3 ~ 50μ.τη, minor axis 0

A resin composition comprising whisker-like calcium carbonate having a ratio of 3 to 2.0 / m and an aspect ratio (major axis / minor axis) of 5 to 50.

2. The resin composition according to claim 1, wherein the amount of the calcium carbonate is 5 to 50% by weight.

3. The resin composition according to claim 1, wherein the calcium carbonate carbonate has a BET specific surface area of up to 15 m ² / g.

4. Claims wherein the calcium carbonate is surface-treated with at least one selected from a silicone surface treatment agent, a titanate surface treatment agent, a carboxylic acid surface treatment agent, and a sulfonic acid surface treatment agent. 4. The resin composition according to any one of 1 to 3.

5. The resin composition according to any one of claims 1 to 4, wherein the particulate filler is finely divided calcium carbonate.

6. The resin composition according to any one of claims 1 to 5, wherein the blending amount of the grain filler is 10 to 80% by weight.

7. The resin composition according to any one of claims 1 to 6, further comprising wollastonite.

8. The resin composition according to any one of claims 1 to 7, wherein the amount of wollastonite is 5 to 30% by weight.

9. The resin composition according to any one of claims 1 to 8, wherein the heat-resistant thermoplastic resin is a polyarylene sulfide resin.

10. A molded article for light reflection obtained by molding the resin composition according to any one of claims 1 to 9. 11. The molded article for reflecting light according to claim 10, wherein the molded article for reflecting light is a lamp reflector.