JPH10219106A - Resin composition for weld molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin compsn. which is suitable for weld molding without detriment to the excellent characteristics inherent in a nylon resin by compounding glass fibers having a specified average diameter, a matrix resin comprising a high-grade nylon resin and a nylon 6 resin and/or a nylon 66 resin, and a copper compd. SOLUTION: This compsn. contains 100 pts.wt. matrix resin contg. a high- grade nylon resin having the number of carbon atoms per amide group of 7 or higher and a nylon 6 resin and/or a nylon 66 resin, 10-150 pts.wt. glass fibers having an average diameter of 5-15μm, and 0.01-2 pts.wt. copper compd. Pref., the half-crystallization time of a mixture of the matrix resin and the glass fibers in such a wt. ratio as described above is at least 40sec when measured at a temp. lower than the m.p. of the resin by 40 deg.C after the mixture is kept in the molten state at a temp. higher than the m.p. by 30 deg.C for 5min. The copper compd. is pref. a copper (I) compd., esp. a copper (I) halide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for welding molding which is excellent in heat resistance, surface appearance of a molded product, dimensional stability, and adhesiveness of a molded product in welding molding such as two-color molding. More particularly, the present invention relates to a nylon resin composition suitable for a hollow molded article obtained by welding and the like.

[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, the design of conventional nylon resin materials cannot be said to take into account the applicability to such post-processing. For example, a glass fiber reinforced nylon resin molded product composed of two or more parts is represented by a two-color molding method. In particular, when the parts are large in size when they are bonded by an injection welding method, the strength of the bonding part is insufficient with a typical nylon resin such as nylon 66 resin, and the dimensional change due to water absorption with nylon 6 resin. At present, use was limited due to problems such as large size.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to improve the adhesion at the time of fusion molding and the strength of the welded portion at the time of water absorption or contact with an automobile antifreeze, which are problems with the above-mentioned conventional nylon resin. Furthermore, a nylon resin composition suitable for the welding molding method that is excellent in the inherent properties of nylon resin such as moldability, heat resistance, toughness, oil / gasoline resistance, abrasion resistance, surface smoothness of molded products, etc. The challenge is to obtain.

[0004]

The inventors of the present invention have studied to solve the above-mentioned problems, and as a result, as a matrix resin in a glass fiber reinforced nylon resin, a specific high-grade nylon resin and a nylon 6 resin and / or a nylon 66 resin.
The present inventors have found that the object can be achieved by using a resin in combination and further containing a copper compound, and have reached the present invention. That is, the present invention provides: "(A) 100 parts by weight of a nylon resin containing (a) a higher nylon resin having 7 or more carbon atoms per amide group and (b) a nylon 6 resin and / or a nylon 66 resin, B) Average fiber diameter 5
10 to 150 parts by weight of 15 μm glass fiber and (C)
A resin composition for fusion molding, comprising 0.01 to 2 parts by weight of a copper compound. 1. "(A) (a) a higher nylon resin having 7 or more carbon atoms per amide group and (b) nylon 6
(B) an average fiber diameter of 5-1 to 100 parts by weight of nylon resin containing resin and / or nylon 66 resin.
The composition is composed of 10 to 150 parts by weight of 5 μm glass fiber, and after the composition is melt-held at a temperature 30 ° C. higher than the melting point of the nylon resin for 5 minutes, a half-crystallization time measured at a temperature 40 ° C. lower than the melting point is 40 seconds or more. A resin composition for welding molding, characterized in that: "3. "The nylon resin of the component (a) is at least one selected from nylon 69, nylon 610, nylon 612, nylon 1010, nylon 1012, nylon 126, nylon 129, nylon 1210, nylon 1212, nylon 11, and nylon 12. 3. The resin composition for fusion molding according to the above item 1 or 2. " 4. The resin composition for welding according to any one of the above items 1 to 3, wherein the nylon resin (b) is a nylon 6 resin. 5. The resin composition for fusion molding according to any one of the above items 1 to 3, wherein the nylon resin (b) is a nylon 66 resin. 6. The resin composition for welding according to any one of the above items 1 to 3, wherein the nylon resin (b) is a mixture of a nylon 66 resin and a nylon 6 resin. "The above 1 and 3 wherein the copper compound is a monovalent copper compound.
6. The resin composition for fusion molding according to any one of items 1 to 5. 8. "The above 7 wherein the monovalent copper compound is cuprous halide
The resin composition for welding molding according to the above. 9. “(A) 100 parts by weight of (a) a higher-grade nylon resin having 7 or more carbon atoms per amide group and (b) 100 parts by weight of a nylon resin containing a nylon 6 resin and / or a nylon 66 resin, B) Average fiber diameter 5
10 to 150 parts by weight of 15 μm glass fiber and (C)
A method for producing a resin composition for fusion molding, comprising mixing 0.01 to 2 parts by weight of a copper compound. 10. “(A) 100 parts by weight of (a) a higher-grade nylon resin having 7 or more carbon atoms per amide group and (b) 100 parts by weight of a nylon resin containing a nylon 6 resin and / or a nylon 66 resin, B) Average fiber diameter 5
A method for producing a composition, comprising mixing 10 to 150 parts by weight of a glass fiber of 15 to 15 μm, wherein the composition is melted and held at a temperature 30 ° C. higher than the melting point of the nylon resin for 5 minutes, and then is melted at a temperature 40 ° C. above the melting point. A method for producing a resin composition for fusion molding, wherein the half-crystallization time measured at a temperature lower by ° C is 40 seconds or more. 11. 11. A method for producing a weld-molded article, characterized in that the resin composition is weld-molded using the resin composition for weld-molding described in any one of 1 to 8 above. It is intended to provide a "welded molded article formed by fusion molding using the resin composition for fusion molding according to any one of the above 1 to 8".

[0005]

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

The nylon resin used as the component (a) in the present invention is a higher nylon resin having at least 7 carbon atoms per amide group, and is a lactam or amino acid having at least 7 carbon atoms, or a diamine and a dicarboxylic acid. Among the combinations with an acid, it is a higher nylon resin containing a structural unit derived from a polyamide-forming component such as a substantially equimolar salt which satisfies the above-mentioned amide group concentration requirement as an essential component.
Examples of these polyamide-forming components include amino acids such as 11-aminoundecanoic acid, 12-aminododecanoic acid, paraaminomethylbenzoic acid, enantholactam,
lactams such as ω-laurolactam, tetramethylenediamine, hexamerenediamine, 2-methylpentamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- /
2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, meta-xylenediamine,
P-xylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3
5,5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine, etc. Aliphatic, alicyclic, aromatic diamines and adipic acid, spearic acid, azelaic acid, sebacic acid, dodecane diacid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, Aliphatic, alicyclic, such as methyl isophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid,
And aromatic dicarboxylic acids. Specific examples of particularly useful high-grade nylon resins include nylon 6.9, nylon 6.10, nylon 6.12, nylon 10.10, nylon 10.12, nylon 11.
6, nylon 11/10, nylon 11/12, nylon 12.6, nylon 12/10, nylon 12.1
2, nylon 12T, nylon 11, nylon 12, nylon 6T / 6I copolymer, nylon 6T / M-5T copolymer, and mixtures and copolymers thereof.

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

In the present invention, nylon 6 resin or nylon 66 resin is used as the component (b). Nylon 6 resin and nylon 66 resin are polycapramide and polyhexamethylene adipamide, respectively, and are copolymers in which other polyamide components are introduced within a range that does not impair the properties of these polymers (for example, less than 2% by weight). Is also included.
The degree of polymerization of nylon 6 resin and nylon 66 resin used here is not particularly limited,
The relative viscosity measured at 25 ° C. is in the range of 1.5 to 5.0,
Particularly, those having a range of 1.8 to 4.0, more preferably 2.0 to 3.5 are preferably used. (A) In nylon resin,
The blending amount of the high-grade nylon (a) is preferably 1% by weight or more, 5% by weight or more, 10% by weight or more and 20% by weight or more, and 99% by weight or less, 95% by weight or less, 90% by weight or less, It is preferable in the order of 80% by weight or less. The sum of the amounts of nylon 6 and nylon 66 in (b) is preferably 1% by weight or more, 5% by weight or more, 10% by weight or more and 20% by weight or more, and 99% by weight or less and 95% by weight. Hereinafter, 90% by weight or less and 80% by weight or less are preferred.

In the present invention, the use of the high-grade nylon resin as the matrix resin in combination with the nylon 6 resin and / or the nylon 66 resin is effective in obtaining a product having a high bonding strength at the time of injection welding such as two-color molding. In addition, it is important to keep the strength of the welded portion high when the welded molded product comes into contact with water or antifreeze. It is not clear why high-grade nylon is used together to obtain a product with high bond strength during welding, but the solidification and crystallization behavior of the resin composition is higher than that of nylon 6 resin, nylon 66 resin, or high-grade nylon resin alone. It is presumed that the slow semi-crystallization time, which reflects the solidification rate when cooled from the molten state, is particularly effective in increasing the miscibility of the bonded part of the molded article.

In the present invention, the glass fiber used as the component (B) is a glass fiber having 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. However, a glass fiber having a strand length of 1 mm or more and a glass fiber having a fiber length of 20 to 500 μm can also be used as a raw material as a mixture. When two or more types of glass fibers having different strand lengths are used in combination, it is also a preferable method to use glass fibers having different average diameters of 2 μm or more.

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, per 100 parts by weight of the nylon resin.

The copper compound used as the component (C) in the present invention is preferably blended. Specific examples include cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, cupric iodide, cupric sulfate, cupric nitrate , Copper phosphate, cuprous acetate, cupric acetate, cupric salicylate, cupric stearate, cupric benzoate and the above-mentioned inorganic copper halides and xylylenediamine, 2-mercaptobenzimidazole, benzimidazole And the like. 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, and 0.015 parts by weight
It is preferably in the range of 1 to 1 part by weight. If the addition amount of the copper compound is less than 0.01 part by weight, the strength of the welded portion during welding and molding, such as two-color molding, tends to be insufficient. The liberation of metallic copper occurs and the coloring reduces the value of the product. 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.

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 fiber, 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. Further, it is more excellent to pre-treat and use these fibrous / non-fibrous fillers with coupling agents such as isocyanate compounds, organic silane compounds, organic titanate compounds, organic borane compounds and epoxy compounds. It is preferable from the viewpoint of obtaining high mechanical strength.

The addition of an alkoxysilane having at least one functional group selected from 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 mechanical 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 contains a 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 the raw material nylon resin, glass fiber and copper compound is extruded in a single or twin screw. Depending on the melting point of the nylon resin to be 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 which is effective for improving the adhesive strength at the time of fusion molding may be carried out 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 fusion 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, a molded product obtained by injection molding, extrusion molding, or blow molding is inserted into an injection molding die, and then a new injection molding is performed. It is particularly useful when the two are bonded together, and taking advantage of this advantage, for example, intake system components such as an intake manifold of an automobile, cooling system components such as a water inlet and a water outlet, fuel injection, fuel delivery pipes and the like. It can be suitably used for hollow parts such as system parts and containers such as oil tanks. That.

[0018]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In addition, the blending ratios shown in Examples and Comparative Examples are all by weight.

In the following examples, evaluations of material strength, fluidity, surface smoothness of molded products, and welding strength were performed by the following methods. [Material strength] Measured according to the following standard method. Tensile strength: ASTM D638 Flexural modulus: ASTM D790 [Surface smoothness] A square plate of 80 × 80 × 3 mm is injection-molded, and the sharpness of the reflected image of a fluorescent lamp is visually observed on the surface of the obtained molded product. did. ：: The reflected image of the fluorescent lamp is observed although it is unclear. Δ: The reflected image of the fluorescent lamp cannot be observed. [Semi-crystallization time] Approximately 10 mg of a resin sample was taken in a DSC (Perkin Elmer type 7) sample pan, and heated at 40 ° C.
The temperature is raised to the melting point of the resin + 30 ° C. at a rate of temperature rise / minute and held for 5 minutes. Then, the mixture was rapidly cooled to a temperature of the melting point minus 40 ° C. at a temperature lowering rate of 100 ° C./min, and the time until an exothermic peak due to crystallization was observed was measured and defined as a half crystallization time.

[Measurement of Adhesive Strength] A test piece for measuring bending fatigue was cut in half and had a surface shape shown in FIG. 1 and a thickness of 10 m.
The m test pieces were formed by injection molding of a resin composition obtained by the method described below. One of the molded pieces is inserted into a bending fatigue test piece mold, and the remaining part is newly injection-molded with the same resin composition, and FIG.
A molded article having the shape shown in FIG. 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. 60% by weight of nylon 610 resin having a relative viscosity of 2.80
And 40% by weight of nylon 66 resin having a relative viscosity of 2.70
100 parts by weight of a nylon resin consisting of a mixture of the above, was supplied to a feeder of an extruder operating at a cylinder temperature of 280 ° C. and a screw rotation speed of 150 rpm.
m, and 50 parts by weight of glass fiber having a strand length of 3 mm were melt-kneaded, and the extruded gut was cooled and pelletized with a pelletizer.

The resin composition obtained here is injection-molded and weld-molded into various test pieces to obtain surface smoothness, material strength,
The results of measuring the adhesive strength and the like are as shown in Table 1.

[0024]

[Table 1]

Example 2 Exactly as described in Example 1, except that 0.05 parts by weight of cuprous iodide and 0.2 parts by weight of potassium iodide were further added to the composition of Example 1. Kneading, pelletizing,
Injection molding and physical properties were measured. The results are as shown in Table 1. The composition obtained here had further improved adhesive strength as compared with the composition of the present invention shown in Example 1.

Comparative Example 1 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 nylon 66 having a relative viscosity of 2.70 was used as the nylon resin. 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 Nylon 610 having a relative viscosity of 2.80 as a nylon resin
Kneading, pelletizing, injection molding, and measurement of physical properties were performed in exactly the same manner as described in Example 1 except that only Example 1 was used. The results are as shown in Table 1, and the composition obtained here was also insufficient in adhesive strength as compared with the composition of the present invention shown in Example 1.

Examples 3 and 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 surface smoothness and welding strength and of high practical value.

[0029]

[Table 2]

[0030]

As described above, the nylon resin composition of the present invention is excellent in heat resistance, molded product surface appearance, dimensional stability, and adhesion at the time of fusion molding.
As in the conventional molding method of simultaneously injecting or extruding two or more types of molten resin as welding molding, the molded product obtained by injection molding, extrusion molding, or blow molding is inserted into an injection molding die, and then a new molding is performed. It is particularly useful when both are bonded and used by injection molding.

[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.

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Claims (12)

[Claims] (A) 100 parts by weight of (a) a nylon resin containing (a) a higher-grade nylon resin having 7 or more carbon atoms per amide group and (b) a nylon 6 resin and / or a nylon 66 resin. On the other hand, a resin composition for welding molding comprising (B) 10 to 150 parts by weight of glass fiber having an average fiber diameter of 5 to 15 μm and (C) 0.01 to 2 parts by weight of a copper compound. (A) 100 parts by weight of a nylon resin containing (a) a higher-grade nylon resin having 7 or more carbon atoms per amide group and (b) a nylon 6 resin and / or a nylon 66 resin. On the other hand, (B) 10 to 150 parts by weight of glass fiber having an average fiber diameter of 5 to 15 μm, and the composition is melted and held at a temperature 30 ° C. higher than the melting point of the nylon resin for 5 minutes, and then at a temperature 40 ° C. lower than the melting point. A resin having a half-crystallization time of at least 40 seconds, as measured in the above step. 3. The nylon resin of the component (a) is nylon 6
9, nylon 610, nylon 612, nylon 101
0, nylon 1012, nylon 126, nylon 12
9, nylon 1210, nylon 1212, nylon 1
The resin composition for welding molding according to claim 1 or 2, wherein the resin composition is at least one selected from the group consisting of nylon 12 and nylon 12. 4. The resin composition according to claim 1, wherein the nylon resin (b) is a nylon 6 resin. 5. The nylon resin of component (b) is nylon 66.
The resin composition for fusion molding according to any one of claims 1 to 3, which is a resin. 6. The nylon resin of the component (b) is nylon 66.
The resin composition for fusion molding according to any one of claims 1 to 3, which is a mixture of a resin and a nylon 6 resin. 7. The method according to claim 1, wherein the copper compound is a monovalent copper compound.
And the resin composition for welding molding according to any one of 3 to 5. 8. The resin composition according to claim 7, wherein the monovalent copper compound is cuprous halide. 9. (A) 100 parts by weight of a nylon resin containing (a) a higher-grade nylon resin having 7 or more carbon atoms per amide group and (b) a nylon 6 resin and / or a nylon 66 resin. On the other hand, (B) 10 to 150 parts by weight of a glass fiber having an average fiber diameter of 5 to 15 μm and (C) 0.01 to 2 parts by weight of a copper compound are mixed, and a method for producing a resin composition for welding molding is characterized. . (A) (a) a higher nylon resin having 7 or more carbon atoms per amide group; and (b)
Production of a composition characterized by mixing (B) 10 to 150 parts by weight of glass fiber having an average fiber diameter of 5 to 15 μm with 100 parts by weight of nylon resin containing nylon 6 resin and / or nylon 66 resin. The method according to claim 1, wherein the composition is melt-maintained at a temperature 30 ° C. higher than the melting point of the nylon resin for 5 minutes, and then has a half-crystallization time of 40 seconds or more measured at a temperature 40 ° C. lower than the melting point. A method for producing a resin composition. 11. A method for producing a weld-molded article, wherein the resin composition for weld-molding according to any one of claims 1 to 8 is weld-molded. 12. A weld-molded article formed by welding using the resin composition for weld-molding according to claim 1.