JPH10204287A - Resin composition for two color formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition excellent in heat resistance, surface appearance of molding product, dimensional stability and adhesiveness of molding product, comprising a specific nylon resin, glass fibers and a copper compound in a specific ratio. SOLUTION: This composition comprises (A) 100 pts.wt. of a nylon resin composed of (i) 50-98wt.% of a nylon containing >=75wt.% of a nylon 6 structural unit and (ii) 2-50wt.% a nylon except the nylon resin compounded as the nylon component (i), (B) 10-150 pts.wt. of glass fibers and (C) 0.01-2 pts.wt. of a copper compound such as a cuprous halide and is high in molding fluidity, surface smoothness of molding product and mechanical strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-color molding resin composition having excellent heat resistance, surface appearance of molded products, dimensional stability, and adhesion of molded products.

[0002]

2. Description of the Related Art Nylon resin is widely used as an injection molded product in the fields of automobiles and machine parts because of its excellent injection moldability, heat resistance, toughness, oil / gasoline resistance, and abrasion resistance. It is used for The development process of nylon resin in the above-mentioned fields is mainly based on the substitution of metal materials, and the practical use has been advanced from parts having many advantages such as weight reduction and rust prevention. More recently, with the advancement of the performance and molding technology of nylon resin materials, the application of nylon resin to parts that are large and have complicated shapes, and for which resinization has been difficult with conventional technology, has been studied. Has become. In order to convert such difficult parts into resin, injection molding, extrusion molding, blow molding and other single molding techniques are not enough.It is necessary to combine post-processing techniques such as cutting, bonding and welding. Become. However, conventional nylon resin materials cannot be said to take into account such applicability to post-processing. For example, a glass fiber reinforced nylon resin molded product composed of two or more parts is bonded by a two-color molding method or the like. When used, the strength of the bonded portion tends to be insufficient, especially when the component is large.

[0003]

SUMMARY OF THE INVENTION As described above, the present invention has a high molding fluidity, a high surface smoothness of a molded article, a high mechanical strength, and has a problem of joining a two-color molded article which has been a problem in a conventional nylon resin. It is an object of the present invention to provide a resin composition and a molded product having high adhesiveness.

[0004]

The inventors of the present invention have studied to solve the above problems, and as a result, used two or more nylon resins having a specific composition as a matrix resin in a glass fiber reinforced nylon resin, and The present inventors have found that the object is achieved by including the compound, and arrived at the present invention. That is, the present invention provides: "(A) 100 parts by weight of nylon resin, (B) 10 to 150 parts by weight of glass fiber and (C) 0.01 of copper compound
(A) a nylon resin comprising: (a) a nylon resin having (a) more than 50% by weight and not more than 98% by weight, and nylon 6 structural units not less than 75% by weight; A resin composition for two-color molding, wherein 2 to 50% by weight is nylon (b) other than the nylon resin blended as the component (a-1). 2. 2. The two-color molding resin composition according to the above 1, wherein the component (a-1) component nylon is a copolymer containing 98 to 80% by weight of a nylon 6 structural unit. 3. The resin composition for two-color molding described in Senki 2 wherein the component (a-1) nylon contains 66 structural units of nylon in the range of 2 to 20% by weight. "(A) For 100 parts by weight of nylon resin,
(B) 10 to 150 parts by weight of glass fiber and (C) 0.01 to 2 parts by weight of a copper compound. (A) In nylon resin, (a) more than 50% by weight and 98% by weight or less. But 75% by weight of nylon 66 structural units
Nylon (a-2) having the above, (b) 2% by weight
The resin composition for two-color molding, wherein more than 50% by weight is a nylon other than the nylon resin blended as the component (a-2). "5. 5. The two-color molding resin composition according to the above 4, wherein the nylon as the component (a-2) is a copolymer containing 98 to 80% by weight of a nylon 66 structural unit. 6. The two-color molding resin composition according to the above item 5, wherein the component (a-1) nylon contains 2 to 20% by weight of a nylon 6 structural unit. 7. The resin composition for two-color molding according to any one of the above, wherein the copper compound is a monovalent copper compound. 8. The resin composition for two-color molding according to any one of the above, wherein the monovalent copper compound is cuprous halide. 9. A method for producing a two-color molded product, comprising performing two-color molding using any of the two-color molding resin compositions described above. "A two-color molded article formed by two-color molding from any one of the above-described two-color molding resin compositions." But mainly consists of two inventions.

[0005]

Embodiments of the present invention will be described below. In the present invention, “weight” means “mass”.

In the polyamide resin of the present invention, 50 to 98
Nylon (a-1) having a nylon 6 structural unit of 75% by weight or more, preferably 80% by weight or more of a nylon 6 structural unit, that is, a nylon 66 structural unit, that is, a structure derived from hexamethylenediamine and a structure derived from adipic acid. The sum of the structures is at least 75% by weight, preferably 80
Nylon (a-2) having a weight percentage of not less than an essential component.

The above (a-1) and (a-2) can be copolymers. Examples of the copolymerizable polyamide-forming component include 6-aminocaproic acid (a-1). Amino acids such as 11-aminoundecanoic acid, 12-aminododecanoic acid, and paraaminomethylbenzoic acid, lactams such as ε-aminocaprolactam (excluding the case of a-1), ω-laurolactam, tetramethylenediamine, hexamerenediamine, 2 -Methylpentamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, metaxylenediamine, paraxylylenediamine, 1 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl Tyl) cyclohexane, 1
-Amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl)
Aliphatic, alicyclic and aromatic diamines such as methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine and aminoethylpiperazine, and adipic acid, speric acid, azelaic acid, sebacic acid , Dodecane diacid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, aliphatics such as hexahydroisophthalic acid, Alicyclic and aromatic dicarboxylic acids are mentioned, and the copolymerization amount of these copolymerization components to be the coupler amide structure or hexamethylene adipamide structure is usually 2 to 20% by weight, preferably 4 to 15% by weight. It is. Among these, particularly useful copolymerized nylon resins are nylon resins having a melting point of 200 ° C. or more and excellent in heat resistance and strength, and specific examples thereof include (a-2)
In the following, polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T), polyhexamethylene adipamide / polyhexamethylene Isophthalamide copolymer (nylon 66 / 6I), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6
6 / 6T / 6I), nylon 66/6 copolymer. Of these, nylon 66/6 copolymer is preferably used.

As a copolymerization ratio, a weight ratio of 66/6 is 80.
/ 20 to 98/2, more preferably 85/15 to 96/4.

[0009] Further, those belonging to the group (a-1) are those having a large number of nylon 6 structural units, and include nylon 6/66 copolymer and nylon 6
/ 12 copolymer is exemplified. As a copolymerization ratio of these two copolymers, a weight ratio of 6 / (66 or 12) is 80/20 to 98/2, and further 85/15 to 96/4.
Is preferable.

Although the degree of polymerization of the nylon resin used here is not particularly limited, in a 1% concentrated sulfuric acid (98%) solution,
The relative viscosity measured at 25 ° C. is in the range of 1.5 to 5.0,
In particular, those having a range of 2.0 to 4.0 are preferably used.

In the present invention, a nylon resin (b) other than the nylon blended as the component (a) is blended. When the polyamide defined as (a-1) is blended as the component (a), a component having a composition ratio defined as the component (a-2) can be blended as the component (b). When the nylon resin defined as (a-2) is blended as the component (a), a resin having a composition ratio defined as the component (a-1) can be blended as the component (b).

The nylon resin used as the component (b) in the present invention is a nylon having a polymerized structure composed of an amino acid, a lactam or a diamine and a dicarboxylic acid as a main component. Representative examples of its main constituents include:
6-aminocaproic acid, 11-aminoundecanoic acid, 1
Amino acids such as 2-aminododecanoic acid and paraaminomethylbenzoic acid, lactams such as ε-aminocaprolactam and ω-laurolactam, tetramethylenediamine, hexamerenediamine, 2-methylpentamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2 1,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, metaxylenediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane 1,1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane,
Aliphatic and alicyclic groups such as bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine and aminoethylpiperazine , Aromatic diamines, and adipic, spearic, azelaic, sebacic, dodecandioic, terephthalic, isophthalic, 2-chloroterephthalic, 2-methylterephthalic, 5-methylisophthalic, and 5-sodium Aliphatic, alicyclic and aromatic dicarboxylic acids such as sulfoisophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid are exemplified.In the present invention, the nylon homopolymer or copolymer derived from these raw materials is (A) It must be the same as the component nylon It can be used each alone or in the form of a mixture under conditions.

In the present invention, specific examples of particularly useful nylon resin (b) are as follows, provided that it is different from (a-1) or (a-2) blended as component (a). , Polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polytetramethylene adipamide (nylon 46), polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612) ), Polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I), polyhexamethylene adipamide / poly Hexamethylene terephthalamide / polyhexamethylene i Phthalamide copolymer (nylon 66 / 6T / 6I), polyxylylene adipamide (nylon XD6) are exemplified.

The degree of polymerization of these nylon resins is not particularly limited, and the relative viscosity measured at 25 ° C. in a 1% concentrated sulfuric acid solution is in the range of 1.5 to 5.0, particularly 2.0 to 4.0. Those in the range of 0 are preferred.

In the present invention, it is important to use a combination of the nylon resins (a) and (b) as the matrix resin in order to obtain a product having a high bonding strength at the time of two-color molding. It is not clear why the combined use can provide a product with high adhesive strength at the time of two-color molding, but the solidification and crystallization behavior of one kind of polyamide changes in the resin composition, and the miscibility of the molded product's adhesive part increases. It is presumed that. Further, the behavior is such that even when (a-1) containing nylon 6 structural units as a major component is blended, nylon 66 structural units are used as a major component.
(a-2), even if they have different structural units, it is considered that they have a common action from the viewpoint of high contribution to crystallinity.

In the present invention, the glass fiber used as the component (B) preferably has an average fiber diameter of 5 to 15 μm, and the fiber length is not particularly limited. Usually, a glass fiber having a strand length of 3 mm having a high extrusion kneading workability can be used as a raw material of the composition of the present invention, and a glass fiber having a strand length of 1 mm or more and a fiber length of 20 to 500 μm are used.
m glass fibers can be used as a mixture as a raw material. When two or more types of glass fibers having different strand lengths are used in combination, the average diameter of the glass fibers used is 2 μm.
It is also a preferred method to use different types.

The total glass fiber content in the resin composition of the present invention is in the range of 10 to 150 parts by weight, more preferably 20 to 80 parts by weight, based on 100 parts by weight of the nylon resin.

If the content of the glass fiber is small, the strength of the obtained molded product is insufficient, and if the content of the glass fiber is large, the adhesiveness of the joint portion of the two-color molded product tends to decrease.

Specific examples of the copper compound used as the component (C) in the present invention include cuprous chloride, cupric chloride, and the like.
Cuprous bromide, cupric bromide, cuprous iodide, cupric iodide, cupric sulfate, cupric nitrate, copper phosphate, cuprous acetate,
Cupric acetate, cupric salicylate, cupric stearate,
Complex compounds of cupric benzoate and the above-mentioned inorganic copper halide with xylylenediamine, 2-mercaptobenzimidazole, benzimidazole and the like can be mentioned. Of these, monovalent copper compounds, particularly monovalent copper halide compounds, are preferred, and cuprous acetate, cuprous iodide and the like can be exemplified as particularly suitable copper compounds. The addition amount of the copper compound is an amount sufficient to improve the strength of the welded portion when the molded article of the resin composition to be formed is adhered by the two-color molding method. 0.01 to 2 parts by weight, more preferably 0.015 to 1 part by weight. If the addition amount of the copper compound is small, the strength of the welded portion during two-color molding tends to be insufficient, and if the amount is large, metal copper is released at the time of melt molding and coloring may reduce the value of the product. is there. In the present invention, it is also possible to add an alkali halide in a form used in combination with a copper compound. Examples of the alkali halide compound include lithium chloride, lithium bromide, lithium iodide, potassium chloride, potassium bromide, potassium iodide, sodium bromide and sodium iodide, and potassium iodide, iodine Sodium chloride is particularly preferred, and when these are blended, the sum is in the range of 0.02 to 4 parts by weight per 100 parts by weight of the nylon resin,
It is preferably in the range of 3 to 3 parts by weight.

In the present invention, it is also possible to add a fibrous / non-fibrous inorganic reinforcing material in addition to the above specific glass fibers. Specific examples of such reinforcing agents include carbon fibers, potassium whisker, titanate, and the like. Zinc oxide whisker, aluminum borate whisker, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, stone fiber,
Fibrous fillers such as metal fibers, wallastenite, zeolite, sericite, kaolin, mica, clay, pyrophyllite, bentonite, asbestos, talc, silicates such as alumina silicate, alumina, silicon oxide, magnesium oxide, zirconium oxide Metal compounds such as titanium oxide and iron oxide; carbonates such as calcium carbonate, magnesium carbonate and dolomite; sulfates such as calcium sulfate and barium sulfate; hydroxides such as magnesium hydroxide, calcium hydroxide and aluminum hydroxide; Examples include non-fibrous fillers such as glass beads, ceramic beads, boron nitride, silicon carbide, and silica. These may be hollow, and two or more of these fillers may be used in combination. In addition, it is more excellent to pre-treat these fibrous / non-fibrous fillers with a coupling agent such as an isocyanate compound, an organic silane compound, an organic titanate compound, an organic borane compound, or an epoxy compound. It is preferable from the viewpoint of obtaining high mechanical strength.

The addition of the alkoxysilane having at least one functional group selected from the group consisting of an epoxy group, an amino group, an isocyanate group, a hydroxyl group, a mercapto group and a ureide group to the nylon resin composition of the present invention is performed by a mechanical method. Strength,
It is effective in improving toughness and the like. Specific examples of such compounds include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane,
epoxy group-containing alkoxysilane compounds such as β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ
-Mercapto group-containing alkoxysilane compounds such as mercaptopropyltriethoxysilane; ureide group-containing such as γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ- (2-ureidoethyl) aminopropyltrimethoxysilane Alkoxysilane compound, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, γ-isocyanatopropylethyldimethoxysilane, isocyanato group-containing alkoxysilane compounds such as γ-isocyanatopropylethyldiethoxysilane and γ-isocyanatopropyltrichlorosilane;
Amino-containing alkoxysilane compounds such as -aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-hydroxypropyltrimethoxysilane, γ- Examples include a hydroxyl group-containing alkoxysilane compound such as hydroxypropyltriethoxysilane.

Further, the nylon resin composition of the present invention includes a crystal nucleating agent such as talc, kaolin, an organic phosphorus compound, polyetheretherketone, a coloring inhibitor such as hypophosphite, a hindered phenol, a hindered amine and the like. Additives such as antioxidants, heat stabilizers, lubricants, UV inhibitors, colorants, etc. can be added.

The method for preparing the nylon resin composition of the present invention is not limited to a specific method. As a specific and efficient example, a mixture of a raw material nylon resin, glass fiber and a copper compound is extruded in a single screw or twin screw. 22 depending on the melting point of the nylon resin used by being supplied to a known melt kneader such as a mixer, a Banbury mixer, a kneader and a mixing roll.
A method of melting and kneading at a temperature of 0 to 330 ° C. can be used.

In the present invention, the addition of a copper compound effective for improving the adhesive strength during two-color molding may be performed in any of the above-mentioned melt-kneading processes. Further, it may be added in advance during the polymerization of the raw material nylon resin. The nylon resin composition of the present invention thus obtained is excellent in heat resistance, molded product surface appearance, dimensional stability, and adhesion at the time of two-color molding, and is usually used as two-color molding. As in the molding method of simultaneously injecting or extruding two or more types of molten resin, the molded product obtained by injection molding, extrusion molding, or blow molding is inserted into an injection mold, and then a new injection molding is performed. It is particularly useful when both are bonded and used, and by taking advantage of this advantage, it can be suitably used for, for example, intake system parts such as an intake manifold of an automobile, and hollow parts such as an oil tank.

[0025]

The present invention will be described more specifically with reference to the following examples. In addition, in the compounding ratios shown in the examples and comparative examples, the value of% means% by weight.

In the following examples, evaluations of material strength, fluidity, surface smoothness of molded articles, and adhesive strength were performed by the following methods. [Material strength] Measured according to the following standard method. Tensile strength: ASTM D638 Flexural modulus: ASTM D790 [Fluidity] Using a spiral flow measurement mold having a spiral shape with a width of 10 mm, a thickness of 2 mm and a total length of 600 mm,
Injection molding temperature 280 ° C, injection molding pressure 30kgf / cm
^{2. When} a material was injection-molded at a mold temperature of 80 ° C., the flow distance in the mold was measured and used as an index of fluidity. The longer the flow length, the better the fluidity. [Surface Smoothness] A square plate of 80 × 80 × 3 mm was injection-molded, and the sharpness of the reflected image of a fluorescent lamp was visually observed on the surface of the obtained molded product, and was used as an index of smoothness. A: A reflected image of a fluorescent lamp is clearly observed. ：: The reflected image of the fluorescent lamp is observed although it is unclear. Δ: The reflected image of the fluorescent lamp cannot be observed. [Measurement of Adhesive Strength] A test piece having a surface shape shown in FIG. 1 and a thickness of 10 mm was obtained by halving a test piece for measuring bending fatigue, and a resin composition obtained by a method described below was subjected to an injection molding method. Molded. One of the molded pieces is inserted into a bending fatigue test piece mold, and the remaining portion is newly injection-molded with the same resin composition, and a molded product having a shape shown in FIG. I got The molded product was subjected to a tensile test, and the breaking strength was defined as the value of the adhesive strength 1.

A test piece 2 having the shape of FIG. 1 obtained separately.
Insert the pieces into the mold so that sides A are in contact with each other,
As shown in FIG. 3, an additional band-shaped portion B having a thickness of 1 mm and a width of 10 mm was injection-molded using the same resin composition with the side A as a center line, and the adhesion test was performed by the band-shaped portion B. I got a piece. The bending strength of the obtained test piece was measured, and the value was defined as adhesive strength 2.

Example 1 Melt kneading of a nylon resin, glass fiber and a copper compound was carried out using a TEX30 type twin screw extruder manufactured by Japan Steel Works. Nylon 66/6 copolymer having a relative viscosity of 2.70 (6
(6/6 = 95/5%) 50%, 20% nylon 6 resin having a relative viscosity of 2.45, and 0.05 parts by weight of cuprous iodide and 0.2 parts by weight based on 100 parts by weight of the nylon resin Dry blending of potassium iodide with a cylinder temperature of 2
It is supplied to the feeder of an extruder operating at 80 ° C. and a screw rotation speed of 150 rpm, and then a glass fiber having a fiber diameter of 9 μm and a strand length of 3 mm is supplied from a side feeder at the tip of the extruder to perform melt-kneading and extrusion. After cooling, the gut was pelletized with a pelletizer.

The resin composition thus obtained was injection-molded into various test pieces, and the fluidity, surface smoothness, material strength, adhesive strength and the like were measured. The results are shown in Table 1.

[0030]

[Table 1]

[0031]

[Table 2]

Comparative Example 1 As a nylon resin, nylon 66 / relative viscosity 2.70 was used.
Kneading, pelletizing, injection molding, and measurement of physical properties were performed in exactly the same manner as described in Example 1 except that only 70% of the 6 copolymer (66/6 = 95/5%) was used. The results are as shown in Table 1. The composition obtained here was insufficient in adhesive strength as compared with the composition of the present invention shown in Example 1.

Comparative Example 2 Kneading, pelletizing, injection molding and measurement of physical properties were carried out in exactly the same manner as described in Example 1 except that only 70% of a nylon 6 resin having a relative viscosity of 2.45 was used as the nylon resin. Was. The results are as shown in Table 1. The composition obtained here was insufficient in adhesive strength as compared with the composition of the present invention shown in Example 1.

Comparative Example 3 Kneading, pelletizing, injection molding and measurement of physical properties were carried out in exactly the same manner as described in Example 1, except that cuprous iodide and potassium iodide were not added. The results are as shown in Table 1. The composition obtained here was insufficient in adhesive strength as compared with the composition of the present invention shown in Example 1.

Examples 2 to 4 Melt kneading and pelletizing were performed in exactly the same manner as described in Example 1 except that the types and amounts of the nylon resin, glass fiber and copper compound used were changed as shown in Table 2. ,
Injection molding and measurement of physical properties were performed, and the results shown in Table 1 were obtained. The composition obtained here was also excellent in fluidity, surface smoothness and adhesive strength and of high practical value.

[0036]

As described above, the two-color molded product obtained from the nylon resin composition of the present invention is excellent in fluidity, surface smoothness and adhesive strength.

[Brief description of the drawings]

FIG. 1 is a plan view showing a shape of a test piece before two-color molding used in an example.

FIG. 2 is a plan view of a test piece whose tensile strength is measured in Examples.

FIG. 3 is a plan view and a side view of a test piece whose bending strength is measured in an example.

Claims (10)

[Claims] (A) 100 parts by weight of a nylon resin, (B)
(A) a nylon resin containing (a) more than 50% by weight and 98% by weight or less of nylon 6;
Nylon (a-1) having a structural unit of 75% by weight or more, and 2% or more and less than 50% by weight of nylon (b) other than the nylon resin blended as the component (a-1)
A two-color resin composition for molding. 2. The resin composition for two-color molding according to claim 1, wherein the component (a-1) nylon is a copolymer containing 98 to 80% by weight of nylon 6 structural units. 3. The two-color molding resin composition according to claim 2, wherein the component (a-1) nylon contains 66 structural units of nylon in the range of 2 to 20% by weight. 4. (A) 100 parts by weight of nylon resin, (B) 10 to 150 parts by weight of glass fiber and (C)
(A) In the nylon resin, (a) more than 50% by weight and 98% by weight or less comprise 75% by weight of the nylon 66 structural unit.
Nylon (a-2) having the above, (b) 2% by weight
A resin composition for two-color molding, wherein less than 50% by weight is nylon other than the nylon resin blended as the component (a-2). 5. The nylon of component (a-2) is nylon 66.
The two-color molding resin composition according to claim 4, which is a copolymer containing 98 to 80% by weight of a structural unit. 6. The two-color molding resin composition according to claim 5, wherein the component (a-1) nylon contains 2 to 20% by weight of nylon 6 structural units. 7. The method according to claim 1, wherein the copper compound is a monovalent copper compound.
7. The resin composition for two-color molding according to any one of claims 6 to 6. 8. The two-color molding resin composition according to claim 7, wherein the monovalent copper compound is cuprous halide. 9. A method for producing a two-color molded article, comprising performing two-color molding using the resin composition for two-color molding according to claim 1. 10. A two-color molded article formed by two-color molding from the resin composition for two-color molding according to claim 1.