JP2702204B2 - Automotive interior parts - Google Patents

Description

Description: BACKGROUND OF THE INVENTION <Industrial Application Field> The present invention relates to a resin-made automobile interior part. More specifically, the present invention relates to an automobile interior part having excellent heat resistance, impact resistance and light resistance, and having a uniformly matte surface.

<Prior Art> Due to the demand for weight reduction, automobile parts, particularly automobile interior parts, which do not require much strength, have been replaced with resin-made parts. Since resin parts can be precisely molded, there is a great demand for a high degree of freedom in design.

Automotive interior parts must be excellent in impact resistance in view of their usage, and therefore, the resin material from which the automobile interior parts are manufactured must be impact resistant.

Various types of impact-resistant resins are already known, but those obtained by graft-polymerizing an aromatic vinyl monomer and a vinyl cyanide monomer onto a rubbery polymer, that is, a rubbery polymer is used. A butadiene polymer in which the aromatic vinyl monomer is styrene and the vinyl cyanide monomer is acrylonitrile is the ABS resin, and the rubbery polymer in the ABS resin is a substantially saturated polymer. Acrylic rubber or ethylene-propylene rubber is AA
As S resin or AES resin, it is frequently used as a representative of so-called engineering plastics.

Such impact-resistant resin has excellent impact resistance due to its rubbery polymer, and also has good moldability, probably due to copolymerization of aromatic vinyl monomer, Also, the dimensional stability, creep resistance and feel are good.

However, such an impact-resistant resin is not necessarily satisfactory when viewed as a material for producing automobile interior parts.

One such problem is that molded articles are too glossy. That is, the above-mentioned impact-resistant resin is relatively rich in gloss, corresponding to copolymerization of an aromatic vinyl monomer, and this property itself can be counted as an advantage. Although it is possible, it is not suitable as a material for automobile interior parts. This is because automotive interior parts require matting for safety requirements and for a sense of luxury.

Elimination of surface gloss can be achieved by painting, but the additional painting step is unacceptable from a cost standpoint. Therefore, from this point of view, matte ABS resin is on the market, and it has been advertised that the final product can be obtained without painting.However, conventionally known matte is not uniform. Interior parts having various shapes, such as poor moldability, insufficient heat resistance, and discoloration or fading due to sunlight reaching the vehicle interior through a windshield or the like. Generally difficult to use.

Therefore, an impact-resistant resin satisfying all of matte uniformity, moldability, heat resistance and light resistance has not been obtained.

<Possible Solution> In view of the above, some of the present inventors have already made one proposal.

That is, Japanese Unexamined Patent Application Publication No. 62-243651 discloses a matte-molded article obtained by mixing a predetermined amount of a specific maleimide-containing copolymer and a metal oxide into the above-mentioned impact-resistant resin. It has succeeded in obtaining a resin composition for production.

However, this composition was also not entirely satisfactory. This is because the moldability was not always good in the balance between the matte uniformity and the heat resistance.

[Summary of the Invention]

<Summary of the Invention> The present invention aims to provide a solution to the above points, and aims to achieve this object by blending a bisamide compound with the above resin composition according to the prior invention of the present inventors. is there.

That is, the automobile interior part according to the present invention comprises the following components (A), (B), (C) and (D), and has a flexural modulus of elasticity of 20,000 to 20,000 as measured according to JIS K7203. 30,000 kg / cm ² , heat deformation temperature without annealing measured according to JIS K7207 90 to 105 ° C, JIS
Izod impact value measured in accordance with K7110 is 8kgcm / c
m or more, and is obtained by molding a resin composition having a 60-degree specular gloss of 40 to 70% on the surface of a molded product measured according to JIS Z8741.

(A) 5-25% by weight of a substantially saturated rubbery polymer portion
And obtained by graft polymerization of this rubbery polymer,
A polymer portion 95-75 consisting of 90-40 mol% of aromatic vinyl monomer residues and 10-60 mol% of vinyl cyanide monomer residues.
(B) 95 to 50 mol% of aromatic vinyl monomer residues, 5 to 50 mol% of maleimide monomer residues, and a copolymer thereof. Copolymer (B) consisting of 0 to 30 mol% of copolymerizable ethylenically unsaturated monomer residues (C) 2 to 50% by weight (C) Metal oxide (C) ... 0.05 to 2% by weight ( D) Bisamide compound: 1 to 3% by weight (the content of (A) and (B) is based on the sum of the two, and the content of (C) and (D) is ( A) and (B).

<Effects of the Invention> According to the present invention, a resin material satisfying the above four characteristics, that is, uniformity of matting, moldability, heat resistance and light resistance in a well-balanced manner, is obtained. Is provided.

Component (B) is an important component in that it has a high content. In fact, increasing the content of component (B) provides a higher matting effect and higher heat resistance. If the content of (B) is high, the moldability tends to deteriorate. Specific component in specific resin composition (component (B))
It is surprising that this problem (deterioration of the moldability) was solved by the bisamide compound and by adding a small amount thereof.

Since the composition of the present invention uses a saturated rubbery polymer as a source of the development of impact resistance, there is no problem of weather resistance inevitable when the composition is unsaturated.

According to the present invention, the flexural modulus is 20,000 to 30,000 kg / cm ²
As the raw material is a molding material with a heat deformation temperature of 90 ° C to 105 ° C and an Izod impact value of 8 kgcm / cm or more,
An automotive interior part having excellent impact resistance, rigidity and heat resistance is provided. In addition, since the 60-degree specular gloss of the surface of the molded product is in the range of 40 to 70%, an automobile interior component that is preferably matte is provided.

[Specific description of the invention]

<Resin Composition> The resin material to be used for manufacturing the automobile interior part according to the present invention is a composition containing the above components (A) to (D). Here, “comprising” means that, in addition to the components (A) to (D) of the indication, a suitable auxiliary material (described in detail below) may be included.

<Component (A)> The component (A) is a component that occupies at least half of the composition of the present invention and should impart innate impact resistance to the resin composition.

The copolymer (A) as the component (A) is a graft copolymer. The graft copolymer is ideally a "stem"
It has a structure in which a “branch” polymer is bonded to a polymer, but in reality, it corresponds to polymerizing a monomer to give a “branch” polymer in the presence of a “trunk” polymer. "Stem"
It will be unavoidable that a polymer of the monomer which does not bind to the polymer is formed as a by-product. Therefore, also in the present invention, when the component (A) is referred to as a graft copolymer, it includes those containing such a non-graft component.

The rubbery polymer of the copolymer (A) as the component (A) in the present invention is a substantially saturated rubbery polymer.
As such a rubbery polymer, any polymer having substantially no ethylenically unsaturated bond and having essentially rubbery elasticity is a target. Specifically, for example, acrylic rubber (for example, butyl acrylate-acrylonitrile copolymer), ethylene-propylene (-non-conjugated diene (for example, ethylidene norbornene)) copolymer rubber, butyl rubber (for example, isobutylene-isoprene copolymer) And others). Some of these rubbery polymers have an ethylenically unsaturated bond to provide a vulcanization site, for example, ethylene-propylene-non-conjugated diene copolymer known as EPDM and isobutylene which is common as butyl rubber −
Examples can be found in isoprene copolymers, but the content of ethylenically unsaturated bonds for such purposes is small, and all such rubbery polymers are the subject of the present invention. Treated as a "substantially saturated" rubbery polymer.

These rubbery polymers have a Mooney viscosity of ML _{1 + 4} (100
C) of about 20 to 120 is suitable.

One of the monomers to form a "branch" polymer is an aromatic vinyl monomer. Typical examples of such a monomer include styrene and a nucleus and / or a side chain-substituted styrene, and vinyl naphthalene and a nucleus and / or a side chain-substituted vinyl naphthalene. Examples of the substituent in this case include a lower alkyl group (preferably having about 1 to 4 carbon atoms), a halogen atom (preferably a chlorine atom), a trifluoromethyl group, a lower alkoxy group, and the like. Specific examples of such an aromatic vinyl monomer include, for example, styrene, α-methylstyrene, p-methylstyrene, p-methylstyrene.
Tertiary butyl styrene, p-chlorostyrene and the like. These may be used in combination.

Another one of the monomers to form a "branch" polymer is a vinyl cyanide monomer. 2 carbon atoms excluding cyano group
Typical ones are about 3 to 3. Specific examples include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, and others. These may be used in combination.

The monomer forming the “branch” polymer is composed of the above two kinds. Here, “consisting of” means a small amount (10% with respect to the total of both components) in addition to the indicated two components. (Up to about mol%).
Such third components include copolymerizable ethylenically unsaturated monomers such as lower alkyl (meth) acrylates, vinylpyridines, vinyl esters such as vinyl acetate, ethylene glycol di (meth) acrylate, There are divinylbenzene and others.

"(Meth) acrylic acid" means both acrylic acid and methacrylic acid.

The copolymer (A) of component (A) comprises 5-25% by weight, preferably 5-20% by weight, of a "backbone" polymer portion (rubbery polymer) and a "branched" polymer portion (complete " It is not limited to the "branch" as described above). 95 to 75% by weight, preferably 95 to 80% by weight. And "branches"
The polymer portion is an aromatic vinyl monomer residue 90 to 40 mol%,
Preferably, it is composed of 80 to 30 mol%, and 10 to 60 mol%, preferably 20 to 70 mol% of vinyl cyanide monomer residues. As described above, these quantitative conditions are those for the produced copolymer (A).

The copolymer (A) of the component (A) can be produced by any method capable of polymerizing an aromatic vinyl monomer and a vinyl cyanide monomer in the presence of a rubbery polymer.

Such methods generally involve the preparation of an aromatic vinyl monomer and a vinyl cyanide monomer (and, optionally, a third monomer) in a rubbery polymer solution, suspension or emulsion. , One time or stepwise, by a radical polymerization mechanism, an ionic polymerization mechanism or the like. Here, when the rubbery polymer is a solution, the solvent is usually an organic solvent inert to the polymerization (it is not necessary to have a dissolving ability for the monomer used or the produced polymer). In Although,
The monomer used can be used as part or all of the solvent.

If the rubbery polymer is obtained as an emulsion,
It may be used as it is as the “emulsion liquid”.

The copolymer (A) in which the rubbery polymer is an acrylic rubber or an ethylene-propylene (-non-conjugated diene) rubber, the aromatic vinyl monomer is styrene, and the vinyl cyanide monomer is acrylonitrile, Impact resistant resins known in the art as AAS resins and AES resins, which are preferred as component (A) in the present invention.

<Copolymer (B)> The copolymer (B) as the component (B) has an aromatic vinyl monomer residue of 95 to 50 mol%, preferably 75 to 60 mol%, and a maleimide monomer residue. 5 to 50 mol%, preferably 25 to 40 mol%, and 0 to 30 mol%, preferably 0 to 20 mol% of ethylenically unsaturated monomer residues copolymerizable therewith.

Although the content is up to 50 mol%, this copolymer (B)
Is a maleimide monomer. Maleimide monomers include maleimide and C- to N-
Substituted maleimides are typical. As for the C-substituent in this case, a suitable one can be found from those described above as the substituent for styrene. Typical examples of the N-substituent include a lower alkyl group, a phenyl group, a lower alkyl-substituted phenyl group, and the like. Among these, N-phenylmaleimide is preferred.

Ethylenically unsaturated monomers which may be copolymerized with both monomers in amounts up to 30 mol% include aromatic vinyl (eg, styrene), vinyl cyanide (eg, acrylonitrile), (meth) Acrylic esters (eg, butyl acrylate, methyl methacrylate), vinyl esters (eg, vinyl acetate), maleic anhydride,
There are divinylbenzene (a little), ethylene glycol di (meth) acrylate (a little), and others. These may be used in combination.

<Component (C)> The component (C) is a metal oxide.

Suitable metal oxides in the present invention include magnesium oxide, calcium oxide, barium oxide, zinc oxide, aluminum oxide, and others. Preferred among these is magnesium oxide. These may be used in combination.

The metal oxide (C) should be sufficiently fine. Specifically, those having an average particle size of 20 microns or less, more preferably 10 microns or less are preferred.

<Component (D)> The component (D) is a bisamide compound.

The bisamide compound referred to in the present invention is a compound having a structure in which an aliphatic monocarboxylic acid amide having about 5 to 20 carbon atoms is bonded by an alkylene group having about 1 to 5 carbon atoms. Examples of the aliphatic monocarboxylic acid amide in this case include so-called fatty acid amides such as caprylic acid (C ₈ ) and capric acid (C
₁₀ ), lauric acid (C ₁₂ ), myristic acid (C ₁₄ ), stearic acid (C ₁₈ ), oleic acid (C ₁₈ ) and other amides are typical, and the bisamide compounds are methylene bis (C ₁ ) and An ethylene bis (C ₂ ) compound is typical. These may be used in combination. Preferred as component (D) in the present invention are methylene bis-stearamide and ethylene bis-stearamide.

<Preparation of Composition> The resin composition comprising the components (A) to (D) can be prepared by any method capable of uniformly dispersing the components. These methods are those commonly used for preparing thermoplastic resin compositions.

One method comprises a step involving melting of the resin component. That is, for example, each component is melt-kneaded by an extruder or the like and extruded to form molding pellets.

One other method consists in mixing the resin component when it is a solution, suspension or emulsion, in that state, and at that time or before or after, mixing components other than the resin component. Things.

Needless to say, it is not essential to form a homogeneous mixture of the components (A) to (D). This is because uniform mixing may be ensured at the time of molding automotive interior parts.

 The contents of the components (A) to (D) are as follows.

(A) 98-50% by weight, preferably 95-60% by weight, (B) 2-50% by weight, preferably 5-40% by weight, (C) 0.05-2% by weight, preferably 0.07-1.0% by weight. (D) 1 to 3% by weight, preferably 1.2 to 2.0% by weight.

Here, the contents of (A) and (B) are based on the sum of both, and the contents of (C) and (D) are based on the sum of (A) and (B). It is.

The content of the components (A) to (D) must be in the above range from the viewpoint of maintaining a good balance of matte uniformity, moldability and heat resistance. For example, if component (B) is 50
Exceeding the weight percentage further enhances the matting properties and heat resistance, but deteriorates the moldability and breaks the good balance of the three properties. The addition of component (C) can lower the gloss (matte) of the surface of the molded article by its addition. However, if it is less than 0.05% by weight or exceeds 2% by weight, the object of the present invention is not achieved. When it exceeds 2% by weight, physical properties such as a reduction in impact resistance are also reduced. Component (D) can improve moldability by its addition, but if it is less than 1% by weight, the effect of improvement is not remarkable, and if it exceeds 3% by weight, the heat deformation temperature is lowered. Absent.

The resin composition containing the components (A) to (D) is JIS K
Flexural modulus measured according to 7203 is 20,000-30,000kg
/ cm ² range, heat deformation temperature without annealing measured according to JIS K7207 90 ° ~ 105 ° C, Izoc impact value measured according to JIS K7110 must be 8kgcm / cm or more . When these requirements are not satisfied, the resin composition has insufficient physical properties and physical properties, particularly impact resistance, rigidity and heat resistance, and the object of the present invention cannot be achieved. Also, JIS Z
The 60 degree specular gloss of the molded product surface measured according to 8741 is 40
If the content is out of the range of 70%, the gloss of the surface of the molded product is too poor or too rich, so that a preferably matt automobile interior part cannot be obtained.

The resin composition according to the present invention falls in the category of a thermoplastic resin composition. Therefore, according to a commonly used place, any auxiliary material can be blended in addition to the essential components (A) to (D) as long as the purpose of the present invention is not impaired. Such auxiliary materials include, for example, antioxidants, ultraviolet absorbers, dyes and pigments, compatible thermoplastic resins, organic or inorganic fillers, and others.

<Automotive interior parts> Except for the fact that the resin material used is the one described above, the automobile interior parts referred to in the present invention are not different from the conventional ones. Due to the excellent properties of the resin composition according to the present invention, the present invention can be applied to components other than conventional resin-made interior parts.

Specific examples of such automotive interior parts include dashboards, instrument panels, defroster garnishes, speaker grilles, front pillar moldings, grab rails, armrests, and others.

The automobile interior parts according to the present invention are most advantageously used without painting because they have a characteristic that the matting is performed uniformly, but if necessary, they are painted, plated or otherwise surface-treated. Needless to say, it is good.

<Experimental Examples> The following are Examples and Comparative Examples for more specifically describing the present invention. The present invention is not limited to the following examples unless it exceeds the gist.

Examples 1 to 4 and Comparative Examples 1 to 6 (1) The following components were prepared as component (A) and component (B).

Component (A): ethylene-propylene-diene monomer (ethylene component 62% by weight, propylene component 33.5% by weight,
4.5% by weight ethylidene norbornene, Mooney viscosity M
L _{1 + 4} (100 ° C) is 42) 20% by weight of rubber component and copolymer of styrene and acrylonitrile (75:25 by weight ratio)
A) a copolymer comprising:

Component (B): a copolymer containing 68 mol% of styrene residues, 25 mol% of phenylmaleimide residues, 2 mol% of maleimide residues, and 5 mol% of maleic anhydride residues.

The above components (A) and (B) are combined in the proportions shown in Table 1, and ethylene bisstearamide is used as the component (C), and magnesium oxide (having an average particle size of 2 μm) is used as the component (D). Further, as another component, an ABS resin (Mitsubishi Monsanto Kasei Co., Ltd., TFX-710) and a blue pigment were weighed at the ratios shown in Table 1 and dry blended with a tumbler. Melt and knead the blend with an extruder,
Pellets were used.

(2) The obtained pellets were subjected to a cylinder temperature of 250 using an injection molding machine (IS 90B, manufactured by Toshiba Machine Co., Ltd.).
° C., injection pressure (gauge pressure) 50kg / cm ^2, as a mold temperature 40 ° C., was molded test pieces and plates. Various properties of the obtained test pieces and molded articles were evaluated by the following methods.

 The results were as shown in Table 1.

(B) Flexural modulus: conformed to JIS K7203.

(B) Thermal deformation temperature: Measured for a non-annealed test piece in accordance with JIS K7207.

(C) Izod impact value: conformed to JIS K7110.

(D) Gloss of molded product surface: Specular gloss at 60 degrees was measured according to JIS Z8741.

(E) Presence or absence of gloss unevenness: The molded product was visually observed.

A sample in which gloss unevenness was not observed throughout the molded article was evaluated as ○, and a sample in which gloss unevenness was observed was evaluated as Δ.

(F) Melt flow: conformed to JIS K7210. The cylinder temperature is 240 ° C, the load is 10 kg, and the outflow for 10 minutes is shown.

(G) Light fastness: A molded product of 40 mm x 60 mm x 2 mm is processed with a fedometer (Suga Test Instruments Co., Ltd., FAL / AU type).
After irradiating for 400 hours under the condition of a black panel temperature of 83 ° C., the black panel was taken out, and its appearance was observed by visual observation.

も の indicates that no color change was observed before and after irradiation, and × indicates that the color changed significantly.

The following is clear from Table 1.

(1) Since the molded article according to the present invention contains the components (A) to (D), the flexural modulus is 20,000 to 30,0.
In the range of 00kg / cm ^2, the thermal deformation temperature is in the range of 90 ° C. to 105 ° C., the impact value as high as 8 kg · cm / cm or more, the surface gloss is preferably adjusted, gloss unevenness without specialties property Is balanced.

(2) On the other hand, if all of the components (A) to (D) are not contained, or if the components do not fall within the scope of the present invention, the physical properties are not balanced.

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Claims (1)

(57) [Claims] 1. A composition comprising the following component (A), component (B), component (C) and component (D), and having a flexural modulus of elasticity of 20,000 to 30,000 kg / cm ² measured according to JIS K7203. , JI
The heat distortion temperature without annealing measured in accordance with S K7207 is 90 ° -105 ° C, the Izod impact value measured in accordance with JIS K7110 is 8 kgcm / cm or more, and measured in accordance with JIS Z8741 60 degree specular gloss of molded product surface is 40 ~ 70
%, Which is obtained by molding a resin composition of (A) 5-25% by weight of a substantially saturated rubbery polymer portion
And obtained by graft polymerization of this rubbery polymer,
A polymer portion 95-75 consisting of 90-40 mol% of aromatic vinyl monomer residues and 10-60 mol% of vinyl cyanide monomer residues.
(B) 95 to 50 mol% of aromatic vinyl monomer residues, 5 to 50 mol% of maleimide monomer residues, and Copolymer (B) consisting of 0 to 30 mol% of copolymerizable ethylenically unsaturated monomer residues (C) 2 to 50% by weight (C) Metal oxide (C) ... 0.05 to 2% by weight ( D) Bisamide compound: 1 to 3% by weight (the content of (A) and (B) is based on the sum of the two, and the content of (C) and (D) is ( A) and (B).