JP2669880B2 - 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 is excellent in heat resistance and impact resistance,
And an automotive interior part having a uniformly matt 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 it is used 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.

The surface gloss can be erased by painting, but the additional painting process is unacceptable in terms of cost. Therefore, from such a point of view, it is said that matte ABS resin is marketed and that the final product can be obtained without painting, but conventionally known ones have uneven matteness or In addition, the moldability is poor and the heat resistance is insufficient, so that it is generally difficult to use it for interior parts having parts of various shapes.

Therefore, an impact resistant resin satisfying all of the matting uniformity, moldability and heat resistance has not been obtained.

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

That is, it is that disclosed in JP-A-62-243651, in which a matte molded article is prepared by blending a predetermined amount of a specific maleimide-containing copolymer of the impact-resistant resin as described above and a metal oxide. 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 component (A), component (B), component (C) and component (D), and has a flexural modulus measured in accordance with JIS K7203 of 20,000 to 30,000 / cm ^2, the thermal deformation temperature without annealing were measured in accordance with JIS K7207 is 90 ° to 105 ° C., JIS K
Izod impact value measured according to 7110 is 12 kgcm / 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 to 25% by weight of a rubbery polymer portion composed of a polymer of butadiene, and 90 to 40 mol% of an aromatic vinyl monomer residue and cyan which are obtained by graft polymerization on the rubbery polymer. Copolymer (A) consisting of 95 to 75% by weight of a polymer portion consisting of 10 to 60% by mole of vinyl chloride monomer residue ... 98 to 50% by weight (B) Aromatic vinyl monomer residue Copolymer (B) consisting of 95 to 50 mol%, maleimide monomer residue 5 to 50 mol%, and copolymerizable ethylenically unsaturated monomer residue 0 to 30 mol%. 50% by weight (C) Metal oxide (C) ...... 0.05 to 2% by weight (D) Bisamide compound ...... 1 to 3% by weight (The contents of (A) and (B) are the total of both. And the content of (C) and (D) is based on the total of (A) and (B)).

<Effects of the Invention> According to the present invention, a resin material satisfying the above-mentioned three characteristics, that is, the uniformity of matting, the moldability and the heat resistance in a well-balanced manner, is obtained, and a satisfactory automobile interior part is provided. It

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.

According to the present invention, the flexural modulus is 20,000 to 30,000 kg / c.
m ^2, the thermal deformation temperature of 90 ° to 105 ° C., since the Izod impact value is a 12 kg · cm / cm or more of the molding material as a raw material, impact resistance, rigidity, automotive interior parts having excellent heat resistance provided To be done. 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
It has a structure in which a "branch" polymer is bonded to a "stem" polymer, but in reality, in the presence of the "stem" polymer, a monomer that should give a "branch" polymer is polymerized. Is equivalent to
It will be unavoidable to form a by-product of the polymer of the monomer that is not bound to the "stem" polymer. 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 polymer of butadiene. Specifically, there are polybutadiene, a butadiene-styrene copolymer, a butadiene-acrylonitrile copolymer (all preferably having a butadiene content of 50% by weight or more), and others. It is suitable that these butadiene copolymers have a Mooney viscosity ML _{1 + 4} (100 ° C.) of about 20 to 120.

One of the monomers that should form the "art" 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 that should form the "art" polymer is vinyl cyanide monomer. Those having about 2 to 3 carbon atoms excluding the cyano group are typical. To give a concrete example,
There are acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, and others. These may be used in combination.

"Technology" The monomers forming the polymer are composed of the above two kinds, but "consisting of" means a small amount (10% with respect to the total of both components) in addition to the two components indicated. It means that it may contain a third component (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 the component (A) is composed of 5 to 25% by weight, preferably 5 to 20% by weight of a “trunk” polymer portion (rubber polymer) and a “technical” polymer portion (complete “ It is as described above that it is not limited to "technique") and is composed of 95 to 75% by weight, preferably 90 to 80% by weight. And "skill"
The polymer portion is an aromatic vinyl monomer residue 90 to 40 mol%,
It is preferably composed of 80 to 30 mol% and vinyl cyanide monomer residues of 10 to 60 mol%, preferably 20 to 70 mol%. 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 rubbery polymer comprising the butadiene polymer targeted by the present invention is usually produced by emulsion polymerization,
The polymerization of the aromatic vinyl monomer and the vinyl cyanide monomer (and optionally a third monomer) is usually carried out in this emulsion.

The copolymer (A) in which the rubbery polymer is polybutadiene or styrene-butadiene rubber, the aromatic vinyl monomer is styrene, and the vinyl cyanide monomer is acrylonitrile is known in the art as an ABS resin. It is one of the preferred impact resistant resins as the 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-
As the C-substituent in which the substituted maleimide is typical, a suitable one can be found from those described above as the substituents of 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, it is preferable that the average particle size is 20 microns or less, more preferably 10 microns or less.

<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 the component (C) can lower the gloss of the surface of the molded article (matte) by adding the component (C), but even if it exceeds 0.05% by weight, the object of the present invention is not achieved. When it exceeds 2% by weight, the physical properties are deteriorated such as the impact resistance being lowered. The component (D) can improve the moldability by its addition, but if it is less than 1% by weight, its improving effect is not remarkable and 3
If it exceeds 5% by weight, the heat distortion temperature lowers, which is not preferable.

The resin composition containing the components (A) to (D) is JIS K7
Flexural modulus measured according to 203 is 20,000-30,000kg /
cm ² range, heat distortion temperature without annealing measured according to JIS K7207 in the range of 90 ° to 105 ° C, Izod impact value measured according to JIS K7110 must be 12 kg ・ cm / cm or more . Outside of these ranges, the physical properties of the resin composition, especially impact resistance, rigidity, and heat resistance are insufficient, and the object of the present invention cannot be achieved. Also, if the 60-degree specular gloss of the surface of the molded product measured in accordance with JIS Z8741 is outside the range of 40 to 70%, the gloss of the molded product surface is too poor or too glossy, which is preferable. No erased car interior parts can 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 that the resin materials used are the above-mentioned ones, the automobile interior parts referred to in the present invention are not different from the conventional ones, because of the excellent properties of the resin composition according to the present invention. The present invention is applicable to other than 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.

<Example> The following are examples and comparative examples for more specifically explaining 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 5 (1) Components (A) and (B) having the following compositions were prepared.

Component (A) A copolymer containing 20% by weight of a polybutadiene component and 80% by weight of a copolymer of styrene and acrylonitrile (weight ratio of 75 to 25).

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, ethylene bis stearamide as the component (C), and magnesium oxide (having an average particle size of 2 μm) as the component (D). Each was weighed in the ratio shown in Table 1 and dry blended with a tumbler. The blended product was melted and kneaded with an extruder to obtain pellets.

(2) Using the injection molding machine (IS90B manufactured by Toshiba Machine), the obtained pellets were molded into a test piece at a cylinder temperature of 250 ° C., an injection pressure (gauge pressure) of 50 kg / cm ² , and a mold temperature of 40 ° C. 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) Heat distortion temperature: Compliant with JIS K7207 (no amir).

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

(D) Gloss on the surface of the molded product: The specular gloss of 60 degrees was measured according to JIS Z8741.

(E) Presence or absence of uneven gloss ... The molded product was visually observed.
The case where no gloss unevenness was observed in the entire molded product was judged as ◯, and the case where gloss unevenness was recognized was judged as Δ.

(F) Melt flow: conformed to JIS K7210. The cylinder temperature is 220 ° C, the load is 10 kg, and the outflow rate for 10 minutes is shown.

From Table 1, the following matters become clear.

(1) Since the molded product according to the present invention contains the components (A) to (D), it has a bending elastic modulus of 20,000 to 30,000 kg / cm ^2.
The heat distortion temperature is in the range of 90 ° to 105 ° C, the impact resistance value is as high as 12 kg · cm / cm, the surface gloss is adjusted preferably, there is no uneven gloss, and each physical property is balanced. .

(2) On the other hand, those which do not contain all of the components (A) to (D) (Comparative Examples 2 to 5) or which do not fall within the scope of the present invention even if they do contain (Comparative Example 1) The physical properties are not balanced.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Koji Tanaka, Inventor 6000-69, Kawashima-cho, Yokkaichi, Mie Prefecture (72) Ichiro Umehara 1400, Matsumoto, Yokkaichi-shi, Mie (56) References JP-A-61-72044 (JP, A )

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 according to S K7207 is 90 ° -105 ° C, the Izod impact value measured according to JIS K7110 is 12 kgcm / cm or more, and measured according to JIS Z8741 60-degree specular gloss of the molded product surface is 40-70%,
An automobile interior part characterized by being obtained by molding the resin composition of (A) 5 to 25% by weight of a rubbery polymer portion composed of a polymer of butadiene, and 90 to 40 mol% of an aromatic vinyl monomer residue and cyan which are obtained by graft polymerization on the rubbery polymer. Copolymer (A) consisting of 95 to 75% by weight of a polymer portion consisting of 10 to 60% by mole of vinyl chloride monomer residue ... 98 to 50% by weight (B) Aromatic vinyl monomer residue Copolymer (B) consisting of 95 to 50 mol%, maleimide monomer residue 5 to 50 mol% and ethylenically unsaturated monomer residue 0 to 30 mol% copolymerizable therewith. 50% by weight (C) Metal oxide (C) ...... 0.05 to 2% by weight (D) Bisamide compound ...... 1 to 3% by weight (The contents of (A) and (B) are the total of both. And the content of (C) and (D) is based on the total of (A) and (B)).