JP2720450B2 - Car mirror stay - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a mirror stay for an automobile using a specific polyamide resin composition.

More specifically, the present invention relates to an automobile mirror stay molded from a polyamide resin composition having excellent vibration damping properties, dimensional stability, moldability and mechanical properties.

[Conventional technology]

The relatively heavy molded articles for automobiles such as electric door mirror stays and anti-glare automobile interior mirrors generally have mechanical strength (strength and rigidity, etc.), paintability, and surface smoothness in addition to damping properties. Various performances such as properties and dimensional stability are required.

Metal materials such as zinc have been used as materials for automobile parts and the like that satisfy these various performances.

Metallic materials such as zinc are excellent in vibration damping, but have the drawback that the surface treatment process before painting is complicated and they are heavy, and they are lightweight and excellent in moldability. The appearance of stays and room mirrors was desired.

Although studies have been made on molding door mirror stays and room mirrors for automobiles that require vibration damping properties with synthetic resins such as PET and PBT, none of them have yet been found to have practically satisfactory performance.

[Problems to be solved by the invention]

The present invention relates to a door mirror stay and a room mirror for an automobile made of a polyamide resin composition having excellent mentality, mechanical strength (strength and rigidity, etc.), paintability, surface smoothness, and dimensional stability. To provide a car mirror stay.

[Means for solving the problem]

As a result of intensive studies, the present inventors have found that a molded product obtained from a resin composition comprising a specific polyamide resin and a specific ratio of mica having a specific particle size and glass fiber in a specific ratio has a high mechanical strength (strength, rigidity and control). Vibration properties), paintability, surface smoothness, moldability, warpage, etc., and are extremely useful as automotive mirror stays such as door mirror stays and room mirrors for automobiles. And arrived at the present invention.

That is, the present invention relates to xylylenediamine and α, ω-
The average particle size is 200μ with respect to 100 parts by weight of a polyamide resin obtained from linear aliphatic dihydrochloride (hereinafter referred to as “MX nylon”) or a polyamide resin containing MX nylon as a main component.
The present invention relates to a mirror stay for automobiles formed from a molding polyamide resin composition having excellent vibration damping properties, comprising 15 to 350 parts by weight of mica having a particle size of m or less and 5 to 300 parts by weight of glass fiber.

As the polyamide resin used in the present invention, MX nylon, MX nylon and nylon 6, nylon 66, nylon 6
9, nylon 610, nylon 612 or a mixture with nylon 12.

The MX nylon used in the present invention is composed of metaxylylenediamine alone or a diamine mixture of not less than 60% by weight of metaxylylenediamine and not more than 40% by weight of paraxylylenediamine and an α, ω-linear aliphatic dibasic acid such as adipine It is a polyamide resin synthesized by a polycondensation reaction of an acid, sebacic acid, suberic acid, dodecanedioic acid, eicodioic acid and the like.

In consideration of the balance between moldability and molded article performance among MX nylons, adipic acid is particularly preferable among the above α, ω-linear aliphatic dibasic acids.

In addition, when an aliphatic polyamide resin such as nylon 66 is blended with MX nylon, it is effective over a wide range only from the viewpoint of shortening the moldability, but if the amount exceeds a majority, the mechanical properties deteriorate. Is not preferred.

In the polyamide resin composition of the present invention, a crystalline random copolymer having the following basic molecular structure and obtained from ethylene and vinyl alcohol can be blended in order to improve the coating property.

Here, l and m represent the degree of polymerization.

The content ratio of the ethylene group in the crystalline random copolymer is desirably 20 to 50 mol%. The content of ethylene groups in the random copolymer is 20 mol%
If the amount is less, the heat resistance is reduced, and if it is 50 mol% or more, the effect of improving the coating adhesion is reduced.

The amount of the random copolymer obtained from the above ethylene and vinyl alcohol in the polyamide resin is 0.5 to 60 parts by weight, preferably 4 to 40 parts by weight, based on 100 parts by weight of the polyamide resin.

If the amount of the random copolymer is less than 0.5 part by weight relative to 100 parts by weight of the polyamide resin, the effect of improving coating adhesion is not sufficiently exhibited, and if it exceeds 60 parts by weight, moldability, heat resistance, mechanical strength and Rigidity and the like are impaired, which is not preferable.

The mica used in the present invention can greatly improve various properties of the polyamide resin.

That is, by adding mica to the polyamide resin, the vibration damping property, rigidity, warpage characteristics, and surface smoothness of the polyamide resin are remarkably improved.

Examples of mica used in the present invention include muscovite, phlogopite, biotite, and the like, but are not particularly limited thereto.

Mica having an average particle diameter of 200 μm or less is used.
When the average particle size of the mica is 200 μm or less, excellent surface smoothness can be obtained.

The mixing ratio of mica is 15 to 350 parts by weight, preferably 30 to 200 parts by weight, based on 100 parts by weight of the polyamide resin.

The mixing ratio of mica to 100 parts by weight of polyamide resin is 1
If the amount is less than 5 parts by weight, the contribution to rigidity, warpage characteristics, vibration damping properties, and the like is small. On the other hand, if the mixing ratio of mica is more than 350 parts by weight, moldability and surface smoothness are unfavorably impaired.

In the present invention, if improvement of coating properties is necessary, a random copolymer obtained from the above ethylene and vinyl alcohol is blended, and mica having an average particle size of 200 μm or less is used in a lump with a resin binder. be able to.

In the present invention, when the mica is used in a lump, the effect of improving the coatability of the molded article is produced by the resin binder used.

In this case, the lump includes various shapes such as a pellet and a sphere. The size of the lump is not particularly limited, but a lump having a particle size of 5 mm or less is desirable.

Further, when supplying mica powder from a molding machine hopper, it is difficult to obtain a uniform resin composition when the average particle size of mica is small, so that supplying mica in a lump obtains a more uniform resin composition. be able to.

Examples of the resin binder used for forming mica into a lump include an acrylic resin, a vinyl acetate resin, a styrene resin, an epoxy resin, a polyvinyl alcohol, and a urethane resin. The proportion of these resin binders used is mica
0.01 to 10 parts by weight per 100 parts by weight is preferred.

If the amount of the resin binder used is small with respect to the mica powder, the lump mica tends to collapse, and if the amount of the resin binder used is large, the dispersibility is impaired when kneading into the resin.

Further, in order to improve the dispersibility, the mica may be previously subjected to a surface treatment with a surface treatment agent such as a silane coupling agent or a titanate coupling agent before forming into a lump.

The blending ratio of the glass fiber used in the present invention is 100 parts by weight of the polyamide resin, 5 to 300 parts by weight, desirably.
It is 10 to 250 parts by weight.

If the amount of glass fiber is less than 5 parts by weight with respect to 100 parts by weight of the polyamide resin, no improvement in mechanical strength, thermal properties, etc. will be obtained, and if it is more than 300 parts by weight, moldability, warpage characteristics and surface smoothness will not be obtained. It is not preferable because the properties are impaired.

The polyamide resin composition of the present invention is generally produced by melt-kneading at a temperature higher than the melting point of the polyamide resin by 5 to 50 ° C. in an extruder and then pelletizing.

In the polyamide resin composition of the present invention, further additives such as a stabilizer against deterioration due to oxidation, heat and ultraviolet rays, a nucleating agent, a plasticizer, a release agent, a flame retardant, an antistatic agent, a lubricant and the like are appropriately compounded. be able to.

Further, in the polyamide resin composition used in the present invention, inorganic fillers such as calcium carbonate, talc, wollastonite, and potassium titanate, whiskers of silicon carbide, carbon fibers, and alumina, as long as the object of the present invention is not impaired. -Silica ceramic fiber, barium stearate, carbon black, zinc oxide and the like can be appropriately blended.

[Action and effect of the invention]

Mirror stays for automobiles such as door mirror stays and rearview mirrors for automobiles molded with the polyamide resin composition for molding of the present invention can provide various properties, vibration damping properties, mechanical strength (strength and rigidity) required for automobile parts. Etc.), paintability, surface smoothness, dimensional stability, etc. are sufficiently satisfied, and the product value is extremely high.

〔Example〕

Next, the present invention will be specifically described with reference to Examples and Comparative Examples.

 In addition, the measuring method of the adopted characteristics etc. is as follows.

(1) Mechanical properties: Mechanical properties were determined by the following test methods.

Tensile strength; ASTM D638 Tensile elongation; ASTM D638 Flexural strength; ASTM D790 Flexural modulus; ASTM D790 (2) Vibration damping: Fix one end of a 12 mm wide, 3 mm thick, 215 mm long test piece, and weight on the other end Attach a 500g weight. From the fixed end,
A strain gauge is attached to a position of 60 mm, and the change in fluctuation when the weighted part is pulled by hand and then released is measured by the strain gauge. Direct, logarithmic decay rate (δ) and intrinsic decay rate (SDC
(%)) Was calculated according to the following equation.

δ = 1 / n ln (A ₀ / A _n ) SDC = (1−e ^−2δ ) × 100 where n is the measured frequency, A ₀ is the initial amplitude,
_An represents the n-th amplitude.

(3) Paintability: A urethane resin (manufactured by Kansai Paint Co., Ltd.)
Product name: Urethane PG60 No101) or acrylic urethane resin (Origin Electric Co., Ltd., trade name: Origin plate Z)
A curing treatment was performed for 30 minutes.

Next, 11 cuts each 1 mm wide and 11 mm wide are made with a cutter knife to make 100 1 mm × 1 mm meshes.

Cellophane adhesive tape (Nichiban Co., Ltd., cellophane tape
After the CT-18) was stretched over the cells, the cells remaining when the cells were separated were measured (rice test).

In addition, the rubbish test was performed on both the specimen after the curing treatment (before immersion in warm water) and the specimen after further immersion in warm water of 40 ° C. for 10 days (after immersion in warm water).

(4) Warpage characteristics: The flatness of four corners when fixing the center of a square plate (film gate) of 90 mm in length, 90 mm in width and 1.5 mm in thickness is measured. Was measured.

(5) Surface smoothness: By visual judgment.

：: good (the surface is beautiful, smooth and shining) △: somewhat good (the surface is slightly rough, and there are a few irregularities) Example 1 Poly (meta-xylylenesiapamide) (hereinafter nylon MX)
Abbreviated as D6. Mitsubishi Gas Chemical Co., Ltd., relative viscosity: 2.14
100 parts by weight and nylon 66 (relative viscosity: 2.25)
50 parts by weight of glass fiber chopped strand with a length of 3 mm (Asahi Fiberglass Co., Ltd., trade name: CS03
JAFT-2) 125 parts by weight, 200 parts by weight of mica powder having an average particle size of 90 μm (manufactured by Yamaguchi Mica Co., Ltd., trade name: B-82), random copolymer of ethylene and vinyl alcohol (manufactured by Kuraray Co., Ltd.) Name: EVAL (registered trademark) AP-
F101, content ratio of ethylene group: 32 mol%) and 25 parts by weight, mixed by a tumbler, and mixed with a vented extruder.
After melt-kneading at 0 ° C., the mixture was extruded into a string, cooled in a water bath, cut and dried to produce a pellet-shaped molding material.

Next, this molding material was injection molded at a molding die temperature of 130 ° C. to obtain a molded product.

The test results of the physical properties of the molded article, the vibration damping properties, and the paintability (in this example, urethane resin (Kansai Paint (Chemical Co., Ltd.), trade name: Rethane PG60 No101) were used), warpage characteristics and surface smoothness test results The results are shown in Table 1.

Example 2 The same as Example 1 except that mica powder having an average particle diameter of 6.2 μm was adhered with a urethane resin binder and pelletized mica (trade name: A-21PG manufactured by Yamaguchi Mica Co., Ltd.) was used. To obtain a molded product.

In this example, urethane resin (manufactured by Kansai Paint Co., Ltd., trade name: Urethane PG60 No101) was used for the test of paintability.

 Table 1 shows the test results of the molded product.

Example 3 A pellet-shaped molding material was obtained in the same manner as in Example 2 except that the random copolymer of ethylene and vinyl alcohol was not blended. Next, this molding material was molded in the same manner as in Example 2 to obtain a molded product.

In this example, an acrylic urethane resin (trade name: Origin Plate Z, manufactured by Origin Electric Co., Ltd.) was used for the test of paintability.

 Table 2 shows the test results of the molded product.

Comparative Example 1 A pellet-shaped molding material was obtained in the same manner as in Example 1 except that mica was not blended.

Next, a molded product was obtained in the same manner as in Example 1 using this molding material.

In this comparative example, a urethane resin (manufactured by Kansai Paint Co., Ltd., trade name: Urethane PG60 No101) was used for the test of paintability.

 Table 2 shows the test results of the molded product.

Comparative Example 2 A pellet-shaped molding material was obtained in the same manner as in Example 1 except that mica and a random copolymer of ethylene and vinyl alcohol were not blended. Next, this molding material was molded in the same manner as in Example 1 to obtain a molded product.

In this comparative example, a urethane resin (manufactured by Kansai Paint Co., Ltd., trade name: Urethane PG60 No101) was used for the test of paintability.

 Table 2 shows the test results of the molded product.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location // (C08L 77/06 77:02 29:04)

Claims (5)

(57) [Claims] 1. A polyamide resin obtained from xylylenediamine and α, ω-linear aliphatic dibasic acid, 100 parts by weight, mica having an average particle diameter of 200 μm or less, 15 to 350 parts by weight, and glass fiber of 5 to 300 parts. An automobile mirror stay formed by molding a resin composition consisting of parts by weight. 2. (a) Xylylenediamine and α, ω-
100 parts by weight of a polyamide resin mixture consisting of a majority of the polyamide resin obtained from the linear aliphatic dibasic acid and (b) the remaining amount of the aliphatic polyamide resin, 15 to 350 parts by weight of mica having an average particle diameter of 200 μm or less; An automobile mirror stay formed by molding a resin composition comprising 5-300 parts by weight of glass fibers. 3. The resin composition according to claim 2, wherein the aliphatic polyamide resin is at least one selected from the group consisting of nylon 6, nylon 66, nylon 69, nylon 610, nylon 612, and nylon 12. An automobile mirror stay characterized by the following. 4. The resin composition according to claim 1, further comprising 0.5 to 60 parts by weight of a random copolymer of ethylene / vinyl alcohol in the resin composition according to any one of claims (1) to (3). Mirror stay. 5. A mirror stay for an automobile, wherein the resin composition according to any one of claims 1 to 4, wherein mica having an average particle diameter of 200 μm or less is agglomerated with a resin binder.