JPH05220826A - Automobile outside plate member - Google Patents

Abstract

PURPOSE:To obtain an automobile outside plate member using a thermoplastic resin composition having excellent blow moldability as a raw material, having superior rigidity, particularly rigidity at a high temperature, shock resistance and dimensional stability and having superb coating appearance. CONSTITUTION:Blow moldings are acquired by using a thermoplastic resin composition, in which a 0-35 pts.wt. rubbery substance, a 0.01-10 pts.wt. resin compatibilizing agent and a 10-35 pts.wt. talc mixture composed of 15-85wt. % small-diameteral talc having mean particle size of l-4mum and an aspect ratio of 5 or more and 85-15wt.% large-diametral talc having mean particle size of 5-10mum and the aspect ratio of 5 or more are blended with a 100 pts.wt. resin consisting of a 35-55wt.% polyphenylene ether resin and a 65-45wt.% polyamide resin, as a raw material, and the blow moldings are baking coated at a high temperature of 120-180 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin automobile outer panel member, and more specifically to a blown resin obtained by blow molding a thermoplastic resin composition containing a mixture of small and large talc as an inorganic filler. The present invention relates to an automobile outer panel member obtained by baking a molded product at a high temperature.

[0002]

2. Description of the Related Art A thermoplastic resin composition comprising a polyphenylene ether resin, a polyamide resin, a rubber-like substance and a compatibilizer is widely known (for example, JP-A-56-2).
No. 6913, No. 56-47432, No. 57-1064
No. 2, No. 57-36150, No. 57-65750,
EPC No. 236596). As one of the main uses of these thermoplastic resin compositions, an automobile outer panel member that is baked and painted at a high temperature of 140 to 160 ° C. is put into practical use by taking advantage of its excellent heat resistance and rigidity.

However, the above-mentioned thermoplastic resin compositions have the common problems that thermoplastic resins have a large decrease in rigidity when exposed to high temperatures, a large linear expansion coefficient, and poor dimensional stability. is there.

In order to improve such problems, it has been attempted to add a filler to a thermoplastic resin composition. For example, in JP-A-63-101452,
A resin composition containing wollastonite and / or glass fiber containing calcium silicate as a main component is disclosed. However, this resin composition has a large decrease in impact strength (falling weight impact strength) as the flexural modulus is improved, and is not practically useful as a raw material for automobile outer panels.

Further, JP-A-61-204263 discloses a composition comprising an aromatic polyphenylene ether resin, a copolymer of a styrene compound and an α, β-unsaturated carboxylic acid anhydride and a polyamide resin having a high melting point. Discloses a composition containing talc as a filler. However, although it is mentioned that these compositions have excellent solder heat resistance (deformation, warpage, etc.), they have low impact strength (Izod impact strength) and are limited in their practicality as raw materials for automobile outer panels. There is. Further, nothing is mentioned about the appearance of the coated surface coated with a molded article obtained by blow molding the above composition, that is, the image clarity.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the object of the present invention is to provide a blow molded article obtained by blow molding a novel thermoplastic resin composition having excellent blow moldability. An object of the present invention is to provide an outer panel member for an automobile, which has excellent rigidity, impact resistance and dimensional stability, and has an excellent painted appearance.

[0007]

The present invention provides (A) (a)
1) Polyphenylene ether resin, or a mixture of polyphenylene ether resin and styrene resin 35-5
5% by weight and (a2) polyamide resin 65 to 45% by weight
(B) 0 to 35 parts by weight of a rubber-like substance, (C) the polyphenylene ether resin, or a mixture (a1) of a polyphenylene ether resin and a styrene resin, and the polyamide resin (a
0.01 to 10 parts by weight of one or more compatibilizing agents for improving compatibility with 2), and (D) (d1) small particle having an average particle diameter of 1 to 4 μm and an aspect ratio of 5 or more. Talc 15 to 85% by weight, and (d2) average particle size 5 to 1
Large diameter talc 85-1 with 0 μm and aspect ratio of 5 or more
A blow molded article obtained by blow molding a thermoplastic resin composition containing 10 to 35 parts by weight of a talc mixture of 5% by weight is baked and coated at a high temperature of 120 to 180 ° C. It is a vehicle outer plate member.

The component (A) used in the present invention,
Both the component (B) and the component (C) are known, and those described in the above-mentioned prior art and other known ones can be used.

The polyphenylene ether resin as the component (a1) used in the present invention is a conventionally used one, for example, a polymer having a repeating unit represented by the following general formula [1] and having a number average Molecular weight Mn is 1000
Those of 0 to 30,000 are preferable.

[0010]

[Chemical 1] [In formula, n shows a positive integer. In the above general formula [1], the aromatic ring is substituted with a methyl group, but those substituted with other substituents, those substituted at other positions and the like can also be used. These can be used alone or in combination of two or more.

As the component (a1), the polyphenylene ether resin can be used alone, or it can be used as a mixture with a styrene resin. As such a styrene resin, any polymer can be used as long as it is a polymer of styrene or a copolymer containing styrene as a main component. Specific examples of the styrene-based resin include polystyrene, rubber-reinforced polystyrene, and styrene-acrylonitrilo copolymer. These may be used alone or in combination of two or more in a proportion of 100% by weight or less with respect to the polyphenylene ether resin.

The polyamide resin as the component (a2) used in the present invention has an amide bond [-C
Those having (= O) -NH-] and capable of being heated and melted can be used. Specific examples of such a polyamide resin (a2) include nylon 6, nylon 66 and nylon 12. Nylon 6 and nylon 66 having a number average molecular weight Mn of 10,000 to 50,000 are preferably used. These are 1 type alone or 2
Combinations of more than one species can be used.

The components (a1) and (a) in the component (A)
The ratio of the component 2) is 35 to 55% by weight of the component (a1),
Preferably 40 to 55% by weight, the component (a2) is 65 to 4
It is 5% by weight, preferably 60 to 45% by weight.

Examples of the rubber-like substance as the component (B) used in the present invention include an elastomer and / or a polyolefin resin having a low flexural modulus. Specific examples of such a rubber-like substance (B) include ethylene-propylene rubber, styrene-butadiene-styrene block copolymers, partially hydrogenated styrene-butadiene block copolymers, low density polyethylene and mixtures thereof. ..

The compatibilizing agent of the component (C) used in the present invention improves the compatibility between the component (a1) and the component (a2), and if it has such an action. There is no particular limitation, and known compatibilizers can be used. As such a compatibilizer, for example, an unsaturated carboxylic acid such as maleic anhydride, fumaric acid or apple, or an acid anhydride can be preferably used.

The component (D) used in the present invention is a talc mixture having an average particle size of 1 to 4 μm, preferably 1
Talc (d1) having an aspect ratio of 5 or more, preferably 10 or more, and an average particle diameter of 5 to 10 μm.
m, preferably 6 to 10 μm, and a mixture with a large diameter talc (d2) having an aspect ratio of 5 or more, preferably 10 or more.

When the small-diameter talc (d1) is used alone, the melt viscosity of the resulting thermoplastic resin composition becomes too high (that is, the melt index becomes too small), and the melt unevenness at the time of parison molding during blow molding is caused. This is not preferable because of poor appearance such as. On the other hand, large talc (d
When 2) is used alone, the melt viscosity of the obtained thermoplastic resin composition becomes low (that is, the melt index becomes large), and the drawdown of the parison required as a blow molding composition becomes large. In addition to the decrease in blow moldability, the impact resistance of the blow molded product is significantly decreased, which is not preferable. When the aspect ratio is less than 5, the effect of improving heat resistance rigidity (rigidity at high temperature) is small.

Small diameter talc (d1) or large diameter talc (d
As 2), those having the above-mentioned average particle diameter and aspect ratio are used, and when the one having a weight loss on heating measured at 300 ° C. for 2 hours is about 0.2% by weight or less, blow molding is performed. It is more preferable because the foaming inside the product is reduced and the appearance is less likely to occur.

Small diameter talc (d1) or large diameter talc (d
2) may be used as it is without treatment, but the above (a1)
In order to improve the interfacial adhesiveness with the component and the component (a2) and to improve the dispersibility, it is possible to use those surface-treated with various silane coupling agents, higher fatty acids or other surfactants.

The ratio of the small talc (d1) and the large talc (d2) in the component (D) is 1 for the small talc (d1).
5 to 85% by weight, preferably 40 to 60% by weight, large talc (d2) 85 to 15% by weight, preferably 60 to 4%
It is 0% by weight.

The average particle size of talc according to the present invention is a particle size corresponding to 50% cumulative distribution, as measured by sedimentation type particle size distribution measurement.

The mixing ratio of each component of the thermoplastic resin composition used in the present invention is 0 to 35 parts by weight, preferably 2 to 2 parts by weight of the rubber-like substance (B) per 100 parts by weight of the component (A).
0 parts by weight, the compatibilizing agent (C) is 0.01 to 10 parts by weight, preferably 0.01 to 7 parts by weight, and the talc mixture (D) is 1 part by weight.
It is 0 to 35 parts by weight, preferably 10 to 30 parts by weight.
If the blending amount of the talc mixture (D) is less than 10 parts by weight, a resin composition excellent in dimensional stability and rigidity at high temperature cannot be obtained. On the other hand, if the amount exceeds 30 parts by weight, the appearance becomes poor.

If desired, the thermoplastic resin composition used in the present invention may contain pigments, ultraviolet absorbers, heat stabilizers, flame retardants, antioxidants, plasticizers and the like.

The thermoplastic resin composition can be produced by melt-kneading using a known kneader such as a single-screw extruder, a twin-screw extruder, a kneader or a roll. Among these, it is preferable to melt-mix and manufacture using an extruder.

The automobile outer panel member of the present invention is a blow molded article molded from the thermoplastic resin composition as described above. Specific members include spoilers, trunk lids, side moldings, sill moldings, bumpers, and the like.

There are no particular restrictions on the molding conditions at the time of blow molding, but since polyamide resin (nylon-based material) is blended, molding is performed with careful attention to material drying and temperature control.

The thermoplastic resin composition used in the present invention is excellent in blow moldability. Blow molding can be carried out using a general blow molding machine, but it is particularly preferable to use a blow molding machine for engineering plastics excellent in temperature control accuracy.

Since the blow-molded product of the present invention is excellent in heat resistance and rigidity at high temperature, high temperature baking coating at 120 to 180 ° C. is possible. As the paint used for such high temperature baking coating, known ones can be used, but as the primer, the molded article substrate, the adhesion to the intermediate coating film,
Further, in order to improve impact resistance (preventing notch effect of top coat and intermediate coat), it is preferable to use polyurethane paint or polyolefin paint. Further, these primers can also be used as a primer having conductivity when electrostatic coating is performed.

As the intermediate coating material, it is preferable to use an epoxy ester type coating material, an aminoalkyd type coating material or the like in order to impart adhesion to the top coating film and improve the appearance quality of the top coating.

As the top coating composition, it is preferable to use a coating composition which has excellent appearance as a coating film, has little deterioration in quality due to long-term exposure, has good weather resistance, and has excellent chemical resistance. preferable. Specifically, for example, in the case of solid color, amino alkyd paint, amino acrylic paint, etc., in the case of metallic color, amino acrylic paint, etc. Paints can be used.

The coating method is not particularly limited, and brushing, spraying, roll coater, dipping, electrostatic coating and the like can be used for coating with a conventional coating device. The coating composition is primer, intermediate coating, top coating, and clear coating,
A coating thickness of 50 to 140 μm is preferred.

Since the blow-molded article as the article to be coated has excellent heat resistance, it is possible to obtain an automobile outer panel member having excellent coating surface quality and appearance by performing high temperature baking at 120 to 180 ° C. The baking time is preferably 80 to 40 minutes. The baking condition is that the primer and the intermediate coating are wet on wet at 140 to 160 ° C. for 30 to 20 minutes,
Top coat, 30-2 at a clear temperature of 140-160 ℃
0 minutes is more preferred.

[0033]

As described above, according to the present invention, a thermoplastic resin composition comprising a polyphenylene ether resin, a polyamide resin, a rubber-like substance and a compatibilizer is further mixed with a small-diameter and large-diameter talc mixture as an inorganic filler. Since a specific amount is blended, a thermoplastic resin composition having excellent blow moldability, heat resistance and rigidity, impact resistance, appearance and the like can be obtained,
Since this composition is used as a raw material for automobile outer panel members and baked and coated at a high temperature of 120 to 180 ° C., it is easy to blow mold and has rigidity, particularly rigidity at high temperatures, impact resistance and dimensional stability. It is possible to obtain an automobile outer panel member having excellent properties and an excellent coating appearance.

[0034]

EXAMPLES Examples of the present invention will now be described, but these are merely examples and the present invention is not limited to these. The test method in each example is as follows.

(1) Flexural modulus It was carried out in accordance with ASTM D790. (2) Deflection Temperature Under Load (HDT) According to ASTM 648, load 4.6 kgf / cm ²
It was carried out in. (3) Falling ball impact strength (falling ball breaking height) A ball having a diameter of 50.8 mm and a weight of 535 g was dropped under a temperature condition of -40 ° C or 23 ° C to obtain a breaking height. The drop height is 40 cm at -40 ° C and 100 at 23 ° C.
Up to cm. (4) Evaluation of coating appearance of blow-molded product It was carried out by PGd, which is one of the commonly used method for evaluating coating properties of automobile outer panels. PGd was determined by reading the limit discriminant value of the test pattern reflection image on the measurement surface with a sharpness / gloss meter manufactured by Japan Color Research Institute.
The measurement was repeated 5 times, and the average value was calculated and used as the measured value.

(5) Drawdown With a blow molding machine with an Akicomlator, the cylinder temperature,
The achicomlator temperature and die temperature were set to 260 ° C., the die / core gap was set to 4 mm, the injection parison length was 1000 mm, and the elongation of the parison after 10 seconds was tested and evaluated according to the following criteria. Good (Small): Elongation rate 0 to less than 10% Bad (Large): Elongation rate 10% to cutting drop (6) Shape retention The blow molded product is blown after being left on a flat surface at room temperature for 24 hours or more in an attached state. After fixing both end mounting parts of the molded product, the amount of flexural deformation of the lower surface of the central part was measured with a dial gauge, and the difference from the specified dimension was evaluated according to the following criteria. Small Deformation: Deflection amount in central part is less than 0 to 2 mm Medium Deformation: Deflection amount in central part is less than 2 to 4 mm Large deformation: Deflection amount in central part is 4 mm or more

In each example, the following components were used as the components of the thermoplastic resin composition. -Polyphenylene ether resin (a1) A polymer having a repeating unit represented by the general formula [1] and having a number average molecular weight Mn = 22000.-Polyamide resin (a2) Nylon 6 [number average molecular weight Mn = 22000] -Rubber-like Substance (B) Ethylene propylene rubber [Moonie viscosity (121 ° C) =
60 (according to JIS K6300)]-Small diameter talc (d1) Micron White 5000S, trademark, manufactured by Hayashi Kasei Co., Ltd.
Average particle diameter 2.5 μm, aspect ratio 5 or more, heating weight loss 0.16% by weight (300 ° C., 2 hours) Large diameter talc (d2) talcan powder PKN, manufactured by Hayashi Kasei Co., Ltd., trademark, average particle diameter 8.0 μm, aspect ratio of 5 or more, heating weight loss of 0.
16% by weight (300 ° C, 2 hours)

Example 1 As a thermoplastic resin composition, polyphenylene ether resin: 50 parts by weight Nylon 6: 50 parts by weight Ethylene propylene rubber: 10 parts by weight Maleic anhydride: 0.5 parts by weight Micron White 5000S: 10 parts by weight Talcan Powder PKN: 10 parts by weight of a composition was melt-kneaded using a continuous twin-screw extrusion kneader according to a conventional method to obtain granules, and the composition was blow-molded under the following conditions. Then, a molded product of an automobile rear spoiler was obtained, and this blow molded product was coated under the following conditions. Table 1 shows the performance of this rear spoiler.

Molding conditions: Using a blow molding machine with an accumulator, cylinder temperature 260 ° C., accumulator, die temperature 255
The temperature is set to ~ 260 ° C and the parison temperature is 270.
It was ℃. Mold temperature is 120 ℃, blow pressure is 6Kg /
A molded product was obtained in cm ² . Blow molded products have an average thickness of 3
mm, the size was 1400 mm in length and 200 mm in width.・ Painting conditions We paint the primer and middle coat wet-on-wet,
After baking at 150 ° C. for 30 minutes, a top coat was applied, and then clear coating was performed thereon, followed by baking at 150 ° C. for 30 minutes. The average film thickness was 100 μm. As the primer, Solflex 6100UN-3 (Kansai Paint Co., Ltd., trade name, polyolefin-based paint),
Lugerbake KP x 50 (Kansai Paint Co., Ltd., trade name, polyester paint) as the intermediate coating, and Magicron B732 (Kansai Paint Co., Ltd., trade name, amino acrylic paint) as the top coating. As clear paint, Rugerbake M70 (manufactured by Kansai Paint Co., Ltd., trade name, aminoacrylic paint) was used.

Comparative Example 1 The same procedure as in Example 1 was carried out except that talcan powder PKN (large-diameter talc) was used alone instead of mixing talc in Example 1. The results are shown in Table 1.

Comparative Example 2 The procedure of Example 1 was repeated, except that Micron White 5000S (small diameter talc) was used alone instead of mixing talc. The results are shown in Table 1.

Comparative Example 3 The procedure of Example 1 was repeated except that glass fiber was blended instead of mixing talc. The results are shown in Table 1.

Comparative Example 4 The procedure of Example 1 was repeated, except that calcium carbonate was added instead of mixing talc. The results are shown in Table 1.

[0044]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08L 25/04 LFN 9166-4J 71/12 LQM 9167-4J LQP 9167-4J 77/00 LQV 9286- 4J // B29L 31:30 4F

Claims (1)

[Claims] 1. 100 parts by weight of a resin comprising (A) (a1) 35 to 55% by weight of a polyphenylene ether resin or a mixture of a polyphenylene ether resin and a styrene resin, and (a2) a polyamide resin of 65 to 45% by weight. On the other hand, (B) the rubber-like substance 0 to 35 parts by weight, (C) improving the compatibility of the polyphenylene ether resin or the mixture (a1) of the polyphenylene ether resin and the styrene resin with the polyamide resin (a2). One or more compatibilizers 0.01 to 10
Parts by weight, and (D) (d1) average particle size is 1 to 4 μ
A talc mixture 10 comprising 15 to 85% by weight of small-diameter talc having an aspect ratio of 5 or more and (d2) 85 to 15% by weight of large-diameter talc having an average particle size of 5 to 10 μm and an aspect ratio of 5 or more. The blow-molded product obtained by blow-molding the thermoplastic resin composition containing about 35 to 35 parts by weight is
An automobile outer panel member obtained by baking at a high temperature of 80 ° C.