JPH064739B2 - Low warp styrene resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel low-warp styrene resin composition. More specifically, the present invention is based on a styrene resin and has a low warpage styrene resin which has a small molding shrinkage factor and a small linear expansion coefficient, a high heat deformation temperature, and a good mechanical property and appearance characteristic. The present invention relates to a resin composition.

2. Description of the Related Art In recent years, in the fields of automobiles, office equipment, electric products, etc., it has been attempted to substitute some of the parts, particularly sheet metals, with resin products for the purpose of weight saving, energy saving, and cost reduction. As a result, there is an increasing demand for resins, especially those reinforced with tougheners. For example, a resin composition in which glass fibers are mixed with a crystalline resin such as a polyamide resin, a polyester resin, or a polyacetal resin to improve heat resistance and rigidity, a non-crystalline resin such as a polycarbonate resin, a polyphenylene ether resin, or an ABC resin is used. There has been proposed a resin composition containing glass fibers to improve heat resistance and rigidity.

However, a fibrous material as a reinforcing agent, for example, these resin compositions prepared by blending glass fibers have good rigidity, heat resistance, appearance characteristics, and colorability, but since the glass fibers have directionality, Particularly, when a plate-shaped molded product is manufactured by injection molding, there is a drawback that the molded product is warped. Such warpage is also a major cause of reduced product value for resins intended to replace sheet metal and aluminum die casting.

As a resin composition which has been suppressed from warping up to now, for example, a resin composition comprising a polyethylene terephthalate resin, a fibrous reinforcing filler and a glass foil (Japanese Patent Publication No. 60-17222), a flat glass flake on an aromatic polyester. A resin composition (Japanese Examined Patent Publication No. Sho 60-17223) formed by blending is known.

Also, styrene resins such as ABC resin, rubber modified polystyrene resin, and the like, which are glass flakes or a mixture of glass flakes and a reinforcing filler (JP-A-62-109855).
JP-A-63-183946) and a mixture of glass fiber and glass flakes (Japanese Patent Laid-Open No. 63-183946). However, in these styrene resin compositions, although some degree of warp improving effect is recognized, the impact resistance is not always sufficient and the application is unavoidable.

By the way, in order to improve impact resistance, for example, Izod impact strength, it is important to improve adhesion between a reinforcing material such as glass fiber or glass flakes and a matrix resin, and various methods have been studied so far. However,
Generally, for example, it has been attempted to treat the surface of the reinforcing material used with a silane coupling agent having an amino group (see JP-A-59-232940). However, in such a method, the amount of the silane coupling agent used with respect to the reinforcing material is usually as small as 0.1 to 0.3% by weight, and the Izod impact strength has not been sufficiently improved.

SUMMARY OF THE INVENTION Under these circumstances, the present invention has a small molding shrinkage factor, a small linear expansion coefficient, a high dimensional accuracy, a high heat deformation temperature, and mechanical properties such as impact resistance. The present invention has been made for the purpose of providing a low-warp styrene-based resin composition capable of giving a molded article having good appearance characteristics.

Means for Solving the Problems The present inventor has conducted extensive studies to develop a low warpage styrene resin composition, and as a result, a glass flake or a mixture of a glass flake and a reinforcing filler and a specific silane were added to the styrene resin. It was found that the object can be achieved by adding a predetermined amount of each coupling agent, and the present invention has been completed based on this finding.

That is, the present invention has (A) 100 parts by weight of a styrene-based resin, (B) 5 to 100 parts by weight of a glass flake alone or a mixture of glass flakes and a reinforcing filler, and (C) a reactive terminal functional group. 0.1 to 5 parts by weight of silane coupling agent and (D) flame retardant 4 to 35 used as desired
The present invention provides a low-warp styrene-based resin composition having separate parts by weight.

Hereinafter, the present invention will be described in detail.

Examples of the styrene resin used as the component (A) in the composition of the present invention include polystyrene resin (GPP
S), rubber modified polystyrene resin (HIPS), styrene-
Examples thereof include acrylonitrile copolymer resin (AS), rubber-modified styrene-acrylonitrile copolymer resin (ABS), polycarbonate resin (PC) and polyblends of ABS resin. Among these, particularly ABS resin and polycarbonate. A polyblend of resin and ABS resin is preferred.

In the composition of the present invention, the glass flake alone or a mixture of the glass flake and the reinforcing filler is used as the component (B). The glass flakes are scaly and have a major axis of 1000 μm or less, preferably 1 to 500 μm, after resin blending.
The range of m is also preferable, and the aspect ratio (ratio of major axis to thickness) is 5 or more, preferably 10 or more, and more preferably 30 or more. As the glass flakes, commercially available ones can be used as they are, but they may be appropriately crushed and used when blended with a resin.

If the glass flakes have a major axis of more than 1000 μm, classification may occur during compounding, which may make uniform mixing with the resin difficult. On the other hand, when the aspect ratio is less than 5, the improvement of the heat distortion temperature of the molded product is insufficient.

In the composition of the present invention, the amount of the flaky glass flakes alone or a mixture of the glass flakes and the reinforcing filler is 5 to 150 parts by weight, preferably 10 to 70 parts by weight, per 100 parts by weight of the styrene resin. It is selected in the range of. If this amount is less than 5 parts by weight, the effect of improving mechanical properties and warpage cannot be sufficiently exhibited, and if it exceeds 150 parts by weight, uniform mixing is difficult and moldability and appearance of the composition are deteriorated. When the amount of the glass flakes used is in the range of 10 to 70 parts by weight, the thermal properties, mechanical properties, dimensional accuracy, appearance, etc. are remarkably improved. As the glass flakes, those subjected to surface treatment with various coupling agents such as silane-based or titanate-based may be used, or those not subjected to surface treatment may be used.

In the composition of the present invention, examples of the reinforcing filler that can be used in combination with the glass flakes include glass fiber, carbon fiber,
Examples include short fiber reinforced fillers such as ceramics fibers and metal fibers, and inorganic particles such as glass beads. Regarding the ratio of the reinforcing filler and the glass flake to be used, the ratio is preferably such that the glass flake is 40% by weight or more and the reinforcing filler is 60% by weight or less.

As the silane coupling agent as the component (C) in the composition of the present invention, those having a reactive functional group such as an amino group, an epoxy group, a mercapto group, a vinyl group, or a halogen atom as an end group are used. Specific examples of such a silane coupling agent include 3-amonopropyltriethoxysilane and N- (2-aminoethyl).
Examples include 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-mercaptoxoxypropylmethoxysilane, and vinyltrimethoxysilane. Among these, Those having an amino group, an epoxy group or a mercapto group as a terminal group are preferred.

These silane coupling agents are added in a proportion of 0.1 to 5 parts by weight, preferably 0.3 to 1 part by weight, relative to 100 parts by weight of the styrene resin as the component (A). If this amount is less than 0.1 parts by weight, the adhesion between the matrix resin and the glass flakes or the reinforcing filler will be insufficient, and the Izod impact strength will not be sufficiently improved. There is no significant difference in Izod impact strength, which is rather economically disadvantageous.

These silane coupling agents must be blended separately from the glass flakes of component (B) or the mixture of the glass flakes and the reinforcing fillers. Particularly, the styrene resin and the glass flakes or the reinforcing fillers are extruded. It is advantageous to mix them when kneading.

In the composition of the present invention, a flame retardant can be blended as the component (D) if desired. As the flame retardant, an organic halogen type, an organic phosphorus type, a metal hydroxide flame retardant or the like which is usually used for a styrene resin can be used.

For example, as the organic halogen-based flame retardant, aromatic halogen compounds, halogenated epoxy resins, halogenated polycarbonate resins, halogenated aromatic vinyl polymers, halogenated cyanurate resins, halogenated polyphenylene ethers, halogenated polyphenylene thioethers, etc. Of these, from the viewpoint of thermal stability, the use of aromatic halogen compounds is most preferable. Preferred examples of organic halogen-based flame retardants include decabromodiphenylene oxide, brominated bisphenol epoxy resin, brominated bisphenol phenoxy resin, brominated bisphenol polycarbonate resin, brominated polystyrene resin, brominated crosslinked polystyrene resin, brominated Examples thereof include bisphenol-based cyanurate resin, brominated polyphenylene ether, polybromophenylene ether, decabromodiphenylene oxide, and bisphenol condensate (tetrabromobisphenol A monomer or oligomer thereof).

Further, as the organic phosphorus-based flame retardant, non-halogen-based such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, etc. Phosphate ester, tris (chloroethyl) phosphate, tris (dichloropropyl) phosphate, tris (chloropropyl) phosphate, bis (2,3-dibromopropyl) -2,3-dichloropropyl phosphate, tris (2,3-dibromopropyl) ) Phosphates, halogen-containing phosphates such as bis (chloropropyl) monooctyl phosphate, and phosphorus-containing phosphates such as triphenyl phosphite Ester and the like.

Examples of the metal hydroxide flame retardant include aluminum hydroxide and magnesium hydroxide.

The blending amount of these flame retardants is selected in the range of 4 to 35 parts by weight, preferably 10 to 25 parts by weight, per 100 parts by weight of the styrene resin.

In the present invention, a flame retardant aid having an action of further increasing the effect of the flame retardant can be used. Examples of flame retardant aids include molybdenum trioxide, molybdenum compounds such as ammonium molybdate, antimony compounds such as antimony trioxide, and the like, and antimony trioxide is particularly preferable. The amount of the flame retardant aid used is usually 2-1 per 100 parts by weight of the styrene resin.
It is selected in the range of 0 parts by weight.

In the composition of the present invention, if desired, various additives such as antioxidants such as phenol-based, phosphorus-based and hindered phenol-based antioxidants, stabilizers, titanium oxide and carbon black within a range that does not impair the object of the present invention. And the like, a lubricant such as a metal soap, a fluidity modifier, a reinforcing thermoplastic elastomer such as a styrene-butadiene block copolymer, a polyester type, or a polyesteramide type can be added.

The method for preparing the composition of the present invention is not particularly limited, and any method can be used. For example, the styrene resin as the component (A), the glass flakes as the component (B) alone or a mixture of the glass flakes and the reinforcing filler, the silane coupling agent as the component (C), and the component (D) used as desired. A method in which a flame retardant and other additive components are mixed and melt-kneaded using an ordinary kneader such as various extruders, kneaders, Banbury mixers, or a styrene resin (A) component and a silane (C) component in advance. After melt-kneading with a coupling agent, the glass flakes of the component (B) alone or a mixture of the glass flakes and the reinforcing filler and the flame retardant of the component (D) and various additional components used as desired are added thereto. Then, a method of melt-kneading can be used. The temperature during melt kneading is usually 180 to 300.
It is selected in the range of ° C.

EFFECTS OF THE INVENTION The low-warp styrene resin composition of the present invention is a styrene resin in which flaky glass flakes alone or a mixture of the glass flakes and a reinforcing filler and a specific silane coupling agent, and further, if desired. A mixture of a flame retardant used, having a high heat distortion temperature, excellent mechanical properties, less warpage, and improved molding shrinkage and linear expansion coefficient, resulting in significantly improved dimensional accuracy, and A molded product having a good appearance can be provided. Therefore, it is particularly preferably used as a substitute for sheet metal in office equipment or the like, or as a substitute for high-grade higher-grade resin.

EXAMPLES Next, the present invention will be described in more detail with reference to Examples.
The invention is in no way limited by these examples.

Various properties of the resin composition were obtained and evaluated by the following methods.

(1) Izod impact strength According to ASTM D256, it was also determined using a notched test piece at 23 ° C.

(2) Flexural Modulus Obtained according to ASTM D790.

(3) Heat distortion temperature Obtained according to ASTM D648.

(4) Appearance characteristics of molded product The surface of the injection-molded molded product was visually observed and evaluated.

(5) Flame retardance Based on the UL-94 test method, it was determined using a 1/8 inch thick test piece.

(6) Warpage Using the box-shaped molded product (wall thickness 2 mm, tunnel 1-point gate) shown in FIG. 1, the inner warpage shown in FIG. 2 was measured.

Example 1 ABS resin (Styrac 200, manufactured by Asahi Kasei Corporation)
80 parts by weight, glass flake (Nippon Sheet Glass Co., Ltd. CEF-
150A) 20 parts by weight, silane coupling agent (Toshiba Silicone Co., Ltd., γ-glycidoxypropyltrimethoxysilane, trade name TSL-8350) 0.5 parts by weight, screw diameter 3
Using a 5 mm twin-screw extruder (TEM35B, manufactured by Toshiba Machine Co., Ltd.), melt kneading was performed at 210 ° C. and a screw rotation speed of 75 rpm.
The strand was granulated to obtain pellets of the styrene resin composition.

The pellet was injection-molded to prepare a test piece, and various properties of the obtained test piece were determined. The results are shown in the table.

Example 2 ABC resin (Styrac 200, Asahi Kasei Corporation)
80 parts by weight, glass flakes (manufactured by Nippon Sheet Glass Co., Ltd.)
CEF-150A) 20 parts by weight, glass fiber (Nippon Sheet Glass Co., Ltd.)
Manufactured by RESO3TP79) 0.5 part by weight of a silane coupling agent (manufactured by Toshiba Silicone Co., Ltd., γ-glycidoxypropyltrimethoxysilane, trade name TSL-8350) at a screw diameter of 35 mm. TEM35B, Toshiba Machine Co., Ltd.
Melt-kneading was performed at 210 ° C. and a screw rotation speed of 75 rpm, and strands were granulated to obtain pellets of a styrene resin composition.

The glass fiber was added to the ventro of the extruder with a vibrating feeder, and the other raw materials were added from the extruder hopper and melt-kneaded.

The pellets were injection-molded to prepare test pieces, and various properties of the obtained test pieces were determined. The results are shown in the table.

Examples 3, 4 The types of silane coupling agent are (Toshiba Silicone Co., Ltd., trade name TSL8340) (Example 3), or γ-mercaptopropyltrimethoxysilane (Toshiba Silicone Co., Ltd., trade name TSL8380) (Example 4) Test pieces were prepared in the same manner as in Example 2 and various evaluations were performed. The results are shown in the table.

Example 5 A test piece was prepared in the same manner as in Example 2 except that the amount of the silane coupling agent was changed from 0.5 part by weight to 0.2 part by weight.
Various evaluations were performed. The results are shown in the table.

Example 6 63 parts by weight of ABS resin (Styrac A7930, manufactured by Asahi Kasei), AS resin (Styrac T8402, Asahi Kasei)
13 parts by weight, flame retardant tetrabromobisphenol A
Monomer 23 parts by weight, antimony trioxide 4 parts by weight, chlorinated polyethylene 4 parts by weight, magnesium stearate 0.
4 parts by weight, n-octyl tin maleate 1 part by weight, glass flake (manufactured by Nippon Sheet Glass Co., Ltd., CEF150A)
14 parts by weight, glass fiber (RESO3TP7 manufactured by Nippon Sheet Glass Co., Ltd.)
9) 10 parts by weight, 0.5 parts by weight of a silane coupling agent (manufactured by Toshiba Silicone Co., Ltd., γ-glycidoxypropyltrimethoxysilane, trade name TSL8350) were melt-kneaded in the same manner as in Example 2 to form a strand. Was granulated to obtain pellets of a styrene resin composition.

The glass fiber was added to the ventro of the extruder with a vibration feeder.

The pellets were injection-molded to prepare test pieces, and various properties of the obtained test pieces were determined. The results are shown in the table.

Example 7 In Example 6, the blending amount of ABS resin was 56 parts by weight and AS
6 parts by weight of resin, 2 parts of glass flake
3 parts by weight, 15 parts by weight of glass fiber and 4.0 parts by weight of silane coupling agent
Test pieces were prepared in the same manner as in Example 6 and various evaluations were performed. The results are shown in the table.

Example 8 ABS resin was replaced with AS resin (Styrac 783 Asahi Kasei Kogyo Co., Ltd.)
A test piece was prepared in the same manner as in Example 2 except that it was changed to "made" and various evaluations were performed. The results are shown in the table.

Example 9 40 parts by weight of polycarbonate resin (Novarex 7025A manufactured by Mitsubishi Kasei Co., Ltd.), ABS resin (Styrac A7930)
Asahi Kasei Kogyo Co., Ltd. 20 parts by weight, AS resin (Styrac 783, Asahi Kasei Kogyo Co., Ltd.) 20 parts by weight, glass flake (Nippon Sheet Glass Co., Ltd. CEF150A) 12 parts by weight, glass fiber (Nippon Sheet Glass (Nippon Sheet Glass) Ltd., RESO3TP79) 10 parts by weight,
Silane coupling agent (manufactured by Toshiba Silicone Co., γ-
Glycidoxypropyltrimethoxysilane, (trade name TS
L8350) 0.5 part by weight is melt-kneaded using a twin-screw extruder (TEM35B, manufactured by Toshiba Machine Co., Ltd.) with a screw diameter of 35 mm at 270 ° C. and a screw rotation speed of 75 rpm to granulate strands and form styrene series Pellets of the resin composition were obtained.

The glass fiber was added to the extruder by a vibrating feeder. The pellets were injection-molded to prepare test pieces, and various properties of the obtained test pieces were determined. The results are shown in the table.

Example 10 To the compounding composition of Example 9, 12 parts by weight of tetrabromobisphenol A oligomer and 3 parts by weight of antimony trioxide were further added to prepare a test piece in the same manner as in Example 9, and various evaluations were performed. . The results are shown in the table.

Example 11 Example 2 was repeated except that the amounts of glass flakes and glass fibers were changed to 10 parts by weight respectively.
Test pieces were prepared in the same manner as above, and various evaluations were performed. The results are shown in the table.

Example 12 A test piece was prepared in the same manner as in Example 6 except that the compounding amounts of glass flakes and fibers were changed to 12 parts by weight, and various evaluations were performed. The results are shown in the table.

Example 13 Example 7 was repeated except that the amounts of the glass flake and the glass fiber were changed to 19 parts by weight, respectively.
Test pieces were prepared in the same manner as above, and various evaluations were performed. The results are shown in the table.

Comparative Example 1 A test piece was prepared in the same manner as in Example 1 except that the silane coupling agent was not used, and various evaluations were performed. The results are shown in the table.

Comparative Example 2 Example 2 except that no silane coupling agent was used.
Test pieces were prepared in the same manner as above and various evaluations were performed. The results are shown in the table.

Comparative Example 3 A test piece was prepared in the same manner as in Example 1 except that glass flakes (CEF150A manufactured by Nippon Sheet Glass Co., Ltd.) were changed to glass beads (Tokyo Ballotini Co., Ltd., diameter: 18 μm), and various evaluations were performed. . The results are shown in the table.

Comparative Example 4 A test piece was prepared in the same manner as in Example 2 except that the compounding amount of the silane coupling agent was changed to 0.06 parts by weight, and various evaluations were performed. The results are shown in the table.

Comparative Example 5 Example 1 except that the glass flakes (CEF150A manufactured by Nippon Sheet Glass Co., Ltd.) were changed to mica (200KI manufactured by Kuraray Co., Ltd.).
Test pieces were prepared in the same manner as above and various evaluations were performed. The results are shown in the table.

Comparative Example 6 Test pieces were prepared in the same manner as in Example 1 except that glass flakes (CEF150A manufactured by Nippon Sheet Glass Co., Ltd.) were changed to glass fibers (RESO3TP79 manufactured by Nippon Sheet Glass Co., Ltd.), and various evaluations were performed. The results are shown in the table.

Comparative Example 7 Example 6 except that no silane coupling agent was used.
Test pieces were prepared in the same manner as above and various evaluations were performed. The results are shown in the table.

Comparative Example 8 A test piece was prepared in the same manner as in Example 6 except that the glass flakes were not mixed and the amount of glass fiber added was changed to 24 parts by weight, and various evaluations were performed.

The results are shown in the table.

[Brief description of drawings]

FIG. 1 is a perspective view showing the dimensions of a warpage measuring molded product, and FIG.
The figure is a plan view of the molded product after the test, showing the measurement points of the warp (inward warp).

Claims (6)

[Claims] Claims: (A) 100 parts by weight of styrene resin,
Low warpage obtained by separately blending (B) 5 to 100 parts by weight of a mixture of glass flakes or a mixture of glass flakes and a reinforcing filler and (C) 0.1 to 5 parts by weight of a silane coupling agent having a reactive terminal functional group. Styrenic resin composition. 2. The composition according to claim 1, wherein the silane coupling agent has an amino group, an epoxy group or a mercapto group as a reactive terminal functional group. 3. A mixture of glass flakes and a reinforcing filler comprising 40% by weight or more of glass flakes and 60% by weight of a reinforcing filler.
The composition according to claim 1 or 2, which comprises: 4. A weight ratio of (A) styrene resin to 100 parts by weight,
(B) 5 to 100 parts by weight of glass flakes alone or a mixture of glass flakes and a reinforcing filler, (C) 0.1 to 5 parts by weight of a silane coupling agent having a reactive terminal functional group, and (D) a flame retardant 4 to 35. A low-warpage styrene resin composition obtained by separately blending parts by weight. 5. The composition according to claim 4, wherein the silane coupling agent has an amino group, an epoxy group or a mercapto group as a reactive terminal functional group. 6. A composition according to claim 4, wherein the mixture of glass flakes and reinforcing filler comprises 40% by weight or more of glass flakes and 60% by weight or less of reinforcing filler.