JP2018012759A - Polyamide resin composition for laser welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide resin composition for laser welding which is capable of giving a composite molding excellent in weldability, mechanical strength, and dimensional stability.SOLUTION: The polyamide resin composition for laser welding according to the present invention contains: 0.1-20 pts.mass of a compound (B) having three or more hydroxyl groups in one molecule based on 100 pts.mass of a polyamide resin (A); and a phosphorus-containing compound (C). A phosphorus atom content determined by absorptiometry is 400-3,500 ppm based on the content of the polyamide resin.SELECTED DRAWING: None

Description

  The present invention relates to a polyamide resin composition for laser welding.

  Polyamide resins have excellent mechanical properties, heat resistance and chemical resistance, and are therefore widely used in automobiles, electrical / electronic parts, and other precision equipment parts. Among various applications, polyamide resin has excellent weldability, so it can be used in applications where multiple members are welded, so-called electrical circuit sealing products such as sensors and connectors, and parts having hollow parts such as intake manifolds. It is coming.

  Among various welding techniques, the laser welding technique is capable of local bonding, has the advantages of non-pressure welding, no generation of wear and burrs, and less damage to products, and is a method that is spreading in a wide range of fields. However, the crystalline polyamide resin is not sufficient in laser light transmission and inadequate in laser weldability, so that improvement has been demanded. In addition, since the polyamide resin has poor dimensional stability, problems such as cracking and deformation may occur in the welded molded product.

  Conventionally, as a technique for improving the weldability of polyamide resin, for example, a polyamide resin composition in which a small amount of an amorphous polyamide resin such as polyhexamethylene isophthalamide is blended with a crystalline polyamide resin such as nylon 66 or nylon 6 has been proposed. (See Patent Document 1). However, although the proposed polyamide resin composition has improved dimensional stability, it has a problem that it is inferior in mechanical properties such as strength and rigidity, and has poor weldability. When a filler such as glass fiber is added to improve the mechanical properties, there is a problem that the transmittance of the laser beam is lowered, and the weldability is still insufficient.

  Moreover, as a polyamide resin composition for laser welding in which a filler is blended, a polyamide resin composition in which a reinforcing filler having a specific refractive index is blended with an aromatic polyamide has been proposed (see Patent Document 2). However, although the proposed polyamide resin composition has improved laser light transmittance and improved weldability, these properties are still not sufficient, and there is a problem of poor dimensional stability.

JP 2002-348371 A Special table 2008-308526

  Accordingly, an object of the present invention is to provide a polyamide resin composition for laser welding capable of obtaining a composite molded article excellent in weldability, mechanical strength and dimensional stability in view of these problems of the prior art.

  This invention solves the said subject, Comprising: The polyamide resin composition for laser welding of this invention has three or more hydroxyl groups in 1 molecule with respect to 100 mass parts of polyamide resins (A). Containing 0.1 to 20 parts by mass of the compound (B) and phosphorus-containing compound (C), and the phosphorus atom content determined by spectrophotometric analysis is 400 to 3500 ppm relative to the polyamide resin content It is a characteristic polyamide resin composition for laser welding.

  According to a preferred embodiment of the polyamide resin composition for laser welding of the present invention, the phosphorus-containing compound (C) is at least one selected from the group consisting of phosphorous acid, hypophosphorous acid and metal salts thereof. It is.

  According to a preferable aspect of the polyamide resin composition for laser welding of the present invention, the compound (B) has a hydroxyl group, an epoxy group and / or a carbodiimide group, and the number of hydroxyl groups in one molecule is in one molecule. It is more than the sum of the number of epoxy groups and carbodiimide groups.

  According to a preferred embodiment of the laser-welded polyamide resin composition of the present invention, the compound (B) is a reaction product of a hydroxyl group-containing compound and an epoxy group and / or carbodiimide group-containing compound (b), The reaction rate with the epoxy group or carbodiimide group is 3 to 95%.

  According to a preferred embodiment of the polyamide resin composition for laser welding of the present invention, the compound (B) is a compound having a structure represented by the following general formula (1) and / or a condensate thereof.

(In the general formula (1), X ^{1 to} X ⁶ may be the same or different and each represents OH, CH ₃ or OR. However, the sum of the number of OH and OR is 3 or more. Represents an organic group having an epoxy group or a carbodiimide group, and n represents a range of 0 to 20.

  According to the preferable aspect of the polyamide resin composition for laser welding of the present invention, it contains a laser light absorbing additive.

  The molded article made of the polyamide resin composition for laser welding of the present invention is used as an electric / electronic component.

  In the laser welding method of the present invention, the laser light transmitting molded article comprising the above-mentioned laser welding polyamide resin composition and the laser light absorbing molded article comprising the above laser welding polyamide resin composition are brought into contact with each other, It is a laser welding method characterized by irradiating a laser beam from the laser light transmitting molded product side and laser welding both of them.

  According to the present invention, laser welding capable of providing a composite molded product obtained by laser welding a laser light-transmitting molded product and a laser light-absorbing molded product having excellent weldability, mechanical strength, and dimensional stability. A polyamide resin composition is obtained.

  The polyamide resin composition for laser welding of the present invention can be molded by any method such as injection molding, injection compression molding, compression molding, extrusion molding, blow molding and press molding, and is processed and used for various molded products. be able to. Particularly, the polyamide resin composition for laser welding according to the present invention makes it possible to obtain a molded product excellent in weldability, mechanical strength and dimensional stability, and is used in electrical / electronic related equipment, precision machinery related equipment, automobiles / vehicles. It is effective for laser welding of resin moldings for various uses such as related parts and building materials.

FIG. 1 is a diagram showing a ¹ H-NMR spectrum of a dry blend product of dipentaerythritol and a bisphenol A type epoxy resin. FIG. 2 is a diagram showing a ¹ H-NMR spectrum of a melt-kneaded reaction product of a polyhydric alcohol and an epoxy compound obtained in Reference Example 5.

  Next, an embodiment of the polyamide resin composition for laser welding of the present invention will be described in detail.

  The polyamide resin composition for laser welding of the present invention contains 0.1 to 20 parts by mass of a compound (B) containing three or more hydroxyl groups in one molecule and phosphorus with respect to 100 parts by mass of the polyamide resin (A). It is a polyamide resin composition for laser welding characterized by containing a compound (C) and having a phosphorus atom content determined by a spectrophotometric method of 400 to 3500 ppm with respect to the polyamide resin content. That is, the polyamide resin composition of the present invention is used for laser welding.

  As described above, the polyamide resin composition used in the present invention may be referred to as a polyamide resin (A) and a compound (B) containing three or more hydroxyl groups in one molecule (hereinafter referred to as compound (B)). And a phosphorus-containing compound (C). Hereinafter, each component will be described.

  In the polyamide resin composition used in the present invention, it is considered that the carboxyl terminal group of the polyamide resin (A) undergoes a dehydration condensation reaction with a hydroxyl group in the compound (B) described later. For this reason, it is thought that the polyamide resin (A) is excellent in compatibility with the compound (B).

  The polyamide resin (A) used in the present invention is a polyamide mainly composed of (i) amino acid, (ii) lactam or (iii) diamine and dicarboxylic acid. Representative examples of the raw material of the polyamide resin (A) include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and paraaminomethylbenzoic acid, lactams such as ε-caprolactam and ω-laurolactam, Tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethyl Hexamethylenediamine, 5-methylnonamethylenediamine, aliphatic diamine such as 2-methyloctamethylenediamine, aromatic diamine such as metaxylylenediamine, paraxylylenediamine, 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 Aliphatic diamines such as 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine, aliphatics such as adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid Dicarboxylic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid Aromatic dicarboxylic acids such as acids, 1, - cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and 1,3-like alicyclic dicarboxylic acids such as cyclopentane dicarboxylic acid. In the embodiment of the present invention, as a raw material for the polyamide resin (A), two or more polyamide homopolymers or polyamide copolymers derived from these raw materials can be blended.

  Specific examples of the polyamide resin (A) include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polytetramethylene adipamide (nylon 46), polytetramethylene sebacamide ( Nylon 410), polypentamethylene adipamide (nylon 56), polypentamethylene sebamide (nylon 510), polyhexamethylene sebamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polydecamethylene Adipamide (nylon 106), polydecane methylene sebamide (nylon 1010), polydecane methylene dodecane (nylon 1012), polyundecanamide (nylon 11), polydodecanamide (nylon 12), polycaproamide / poly Hexamethylene adipamide Polymer (nylon 6/66), polycaproamide / polyhexamethylene terephthalamide copolymer (nylon 6 / 6T), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T), polyhexamethylene adipa Mido / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), polyhexamethylene terephthalamide / polyundecanamide copolymer (nylon 6T / 11) , Polyhexamethylene terephthalamide / polydodecanamide copolymer (nylon 6T / 12), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhe Samethylene isophthalamide copolymer (nylon 66 / 6T / 6I), polyxylylene adipamide (nylon XD6), polyxylylene sebacamide (nylon XD10), polyhexamethylene terephthalamide / polypentamethylene terephthalamide copolymer (nylon) 6T / 5T), polyhexamethylene terephthalamide / poly-2-methylpentamethylene terephthalamide copolymer (nylon 6T / M5T), polypentamethylene terephthalamide / polydecamethylene terephthalamide copolymer (nylon 5T / 10T), polynonamethylene Examples include terephthalamide (nylon 9T), polydecamethylene terephthalamide (nylon 10T), and polydodecamethylene terephthalamide (nylon 12T). In addition, specific examples of the polyamide resin include a mixture and a copolymer thereof. Here, “/” indicates a copolymer. The same shall apply hereinafter.

  Particularly preferred polyamide resin (A) is a polyamide resin having a melting point of 200 ° C to 330 ° C. A polyamide resin having a melting point of 200 ° C. to 330 ° C. is excellent in heat resistance and strength. A polyamide resin having a melting point of 200 ° C. or higher can be melt-kneaded under high temperature conditions with a high resin pressure, and the reactivity with the compound (B) described later can be increased. For this reason, the dispersibility of the compound (B) in the polyamide resin composition can be further improved, and the weldability, mechanical strength, and dimensional stability can be further improved. The melting point of the polyamide resin is more preferably 220 ° C. or higher.

  On the other hand, by using a polyamide resin having a melting point of 330 ° C. or lower, the melt kneading temperature can be moderately suppressed, and the decomposition of the polyamide resin can be suppressed. For this reason, weldability, mechanical strength, and dimensional stability can be further improved.

  Here, the melting point of the polyamide resin in the embodiment of the present invention is as follows. After the polyamide resin is cooled from the molten state to 30 ° C. at a temperature decreasing rate of 20 ° C./min under an inert gas atmosphere using a differential scanning calorimeter, It is defined as the temperature of the endothermic peak that appears when the temperature is raised to the melting point + 40 ° C. at a rate of temperature increase of 20 ° C./min. However, when two or more endothermic peaks are detected, the temperature of the endothermic peak having the highest peak intensity is defined as the melting point.

  Examples of polyamide resins having a melting point of 200 ° C. to 330 ° C. include nylon 6, nylon 66, nylon 46, nylon 410, nylon 610, nylon 56, nylon 6T / 66, nylon 6T / 6I, nylon 6T / 12, nylon Examples thereof include copolymers having hexamethyl terephthalamide units such as 6T / 5T, nylon 6T / M5T, and nylon 6T / 6, nylon 5T / 10T, nylon 9T, nylon 10T, and nylon 12T. Among these, nylon 6 is more preferably used as a polyamide resin having an excellent balance of weldability, mechanical strength, and dimensional stability. It is practically preferable to blend two or more of these polyamide resins depending on the required properties such as weldability, mechanical strength and dimensional stability.

  The degree of polymerization of these polyamide resins is not particularly limited, but the relative viscosity (ηr) measured at a temperature of 25 ° C. in a 98% concentrated sulfuric acid solution having a resin concentration of 0.01 g / ml is 1.5 to 5.0. A range is preferable. When the relative viscosity is 1.5 or more, the mechanical strength of the obtained molded product can be further improved. The relative viscosity is more preferably 2.0 or more. On the other hand, if the relative viscosity is 5.0 or less, the weldability can be further improved.

  The polyamide resin composition used in the present invention contains a compound (B) containing three or more hydroxyl groups in one molecule. The hydroxyl group-containing compound can form a crosslinked structure in the polyamide resin composition by a dehydration condensation reaction with the polyamide resin (A), and can improve the mechanical strength and dimensional stability of the obtained molded product. Further, even during laser welding, a crosslinked structure can be formed on the joint surface by the heat of the laser, and the weldability can be improved.

  The compound (B) used in the embodiment of the present invention is a compound having three or more hydroxyl groups in one molecule. A compound having 2 or less hydroxyl groups in one molecule cannot sufficiently form a crosslinked structure in the polyamide resin composition, and the weldability, mechanical strength and dimensional stability are lowered. The number of hydroxyl groups in one molecule is preferably 4 or more, and more preferably 6 or more. The compound (B) may be a low molecular compound, and a polymer is also used.

In the case of a low molecular compound, the number of hydroxyl groups in one molecule of the compound (B) specifies the structural formula of the compound by a usual analysis method (for example, a combination of NMR, FT-IR, GC-MS, etc.) Can be calculated. In the case of a condensate, the number of hydroxyl groups can be determined by the following formula (2) by calculating the number average molecular weight and the hydroxyl value of the compound (B).
Number of hydroxyl groups in one molecule = (number average molecular weight × hydroxyl value) / 56110 (2)
The number average molecular weight of the compound (B) can be calculated using a gel permeation chromatograph (GPC). Specifically, it can be calculated by the following method. A solvent in which the compound (B) is dissolved, for example, hexafluoroisopropanol is used as a mobile phase, and polymethyl methacrylate (PMMA) is used as a standard substance. The column is matched to the solvent. For example, when hexafluoroisopropanol is used, “Shodex GPC HFIP-806M” and / or “Shodex GPC HFIP-LG” manufactured by Shimadzu GL Corporation is used as a detector. The number average molecular weight can be measured using a differential refractometer.

  The hydroxyl value of the compound (B) can be determined by acetylating the compound (B) with a mixed solution of acetic anhydride and anhydrous pyridine and titrating it with an ethanolic potassium hydroxide solution.

  In the polyamide resin composition used in the present invention, the content of the compound (B) is 0.1 to 20 parts by mass (0.1 to 20 parts by mass) with respect to 100 parts by mass of the polyamide resin (A). It is. When the content of the compound (B) is less than 0.1 parts by mass, the weldability, mechanical strength and dimensional stability of the obtained molded product are lowered. The content of the compound (B) is preferably 0.5 parts by mass or more and more preferably 2 parts by mass or more with respect to 100 parts by mass of the (A) polyamide resin.

  On the other hand, when the content of the compound (B) exceeds 20 parts by mass, the compound (B) tends to bleed out to the surface layer of the molded product, and the weldability is lowered. Moreover, plasticization and decomposition of the polyamide resin are promoted, and mechanical strength and dimensional stability are lowered. The content of the compound (B) is preferably 7.5 parts by mass or less and more preferably 6 parts by mass or less with respect to 100 parts by mass of the polyamide resin (A).

  The compound (B) used in the embodiment of the present invention is preferably solid at a temperature of 25 ° C. or a liquid having a viscosity of 200 mPa · s or more at a temperature of 25 ° C. In that case, it becomes easy to obtain a desired viscosity at the time of melt-kneading, the compatibility with the polyamide resin (A) can be further improved, and the weldability, mechanical strength and dimensional stability can be further improved.

  Specific examples of the compound (B) include 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1,2,3,6-hexanetetrol, glycerin. , Diglycerin, triglycerin, tetraglycerin, pentaglycerin, hexaglycerin, ditrimethylolpropane, tritrimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, methylglucoside, sorbitol, glucose, mannitol, sucrose, 1,3, 5-trihydroxybenzene, 1,2,4-trihydroxybenzene, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, triethanolamine, trimethylolethane, trimethylolpropane, 2-methylpropaline Triol, tris (hydroxymethyl) aminomethane, and the like 2-methyl-1,2,4-butanetriol and the like.

  Examples of the hydroxyl group-containing compound also include a hydroxyl group-containing compound having a repeating structural unit, such as an ester bond, an amide bond, an ether bond, a methylene bond, a vinyl bond, an imine bond, a siloxane bond, a urethane bond, a thioether bond, Examples thereof include a hydroxyl group-containing compound having a repeating structural unit having a silicon-silicon bond, a carbonate bond, a sulfonyl bond, and an imide bond.

  The hydroxyl group-containing compound can contain a repeating structural unit containing two or more of these bonds. As the hydroxyl group-containing compound having a repeating structural unit, a hydroxyl group-containing compound having a repeating structural unit having an ester bond, a carbonate bond, an ether bond and / or an amide bond is preferably used.

  A hydroxyl group-containing compound having a repeating structural unit having an ester bond is, for example, a compound having one or more hydroxyl groups, the carbon atom adjacent to the carboxyl group is a saturated carbon atom, and all the hydrogen atoms on the carbon atom are substituted. And can be obtained by reacting a monocarboxylic acid having two or more hydroxyl groups.

  The hydroxyl group-containing compound having a repeating structural unit having an ether bond can be obtained, for example, by ring-opening polymerization of a compound having one or more hydroxyl groups and a cyclic ether compound having one or more hydroxyl groups. A hydroxyl group-containing compound having a repeating structural unit having an ester bond and an amide bond can be obtained, for example, by a polycondensation reaction between an aminodiol and a cyclic acid anhydride. A hydroxyl group-containing compound having a repeating structural unit having an ether bond containing an amino group can be obtained, for example, by intermolecular condensation of trialkanolamine. A hydroxyl group-containing compound comprising a repeating structural unit having a carbonate bond can be obtained, for example, by a polycondensation reaction of an aryl carbonate derivative of trisphenol.

  Among the compounds (B), pentaerythritol, dipentaerythritol and tripentaerythritol are preferably used.

  The polyamide resin composition used in the embodiment of the present invention contains a phosphorus-containing compound (C). Conventionally, phosphorus-containing compounds such as sodium hypophosphite have been used as polycondensation catalysts for polycondensation of polyamides, and are known to shorten polymerization time and to suppress yellowing. In the embodiment of the present invention, a molded product having excellent weldability, mechanical strength, and dimensional stability can be obtained by including the phosphorus-containing compound (C) together with the compound (B). This is because the phosphorus-containing compound (C) is excellent in the effect of promoting the condensation reaction between the polyamide resin (A) and the compound (B), so that a crosslinked structure can be formed in the polyamide resin composition. A molded product having excellent properties, mechanical strength and dimensional stability can be obtained. Moreover, since the dispersibility of the compound (B) in a polyamide resin composition can be improved more, it is excellent in laser transmittance and weldability can be improved more.

  In the polyamide resin composition for laser welding of the present invention, the phosphorus atom content is 400 to 3500 ppm (400 ppm to 3500 ppm) with respect to the content of the polyamide resin (A). Here, the phosphorus atom content in the embodiment of the present invention represents the concentration of phosphorus element determined by an absorptiometric method described later. That is, in the polyamide resin composition for laser welding of the present invention, the content of the phosphorus-containing compound (C) is 400 to 3500 ppm with respect to the content of the polyamide resin (A) in terms of phosphorus atoms (weight basis). . When the phosphorus atom equivalent concentration is less than 400 ppm, the effect of accelerating the condensation reaction between the polyamide resin (A) and the compound (B) is poor, and the weldability, mechanical strength and dimensional stability of the resulting molded article are lowered. The phosphorus atom equivalent concentration of the phosphorus-containing compound (C) is preferably 600 ppm or more, more preferably 800 ppm or more with respect to the content of the polyamide resin (A). On the other hand, when the phosphorus atom conversion density | concentration of a phosphorus containing compound (C) exceeds 3500 ppm, the viscosity increase of a polyamide resin (A) will become remarkable and a moldability will fall. Further, the presence of gas generated by the decomposition of the phosphorus-containing compound (C) due to shearing heat generation in the molded product lowers the weldability, mechanical strength and dimensional stability of the obtained molded product. Further, the phosphorus-containing compound (C) is likely to bleed out to the surface layer of the molded product, and the weldability is further reduced. The content of the phosphorus-containing compound (C) is preferably 3000 ppm or less with respect to the content of the polyamide resin (A) in terms of phosphorus atoms.

  The phosphorus atom conversion density | concentration derived from the phosphorus containing compound (C) with respect to content of the polyamide resin (A) in the polyamide resin composition for laser welding here, ie, phosphorus atom content, can be calculated | required with the following method. First, the polyamide resin composition for laser welding or a molded product thereof is dried under reduced pressure, and then heated for ashing in an electric furnace at a temperature of 550 ° C. for 24 hours, and then the polyamide resin composition for laser welding or an inorganic material in the molded product thereof. The content of is determined. In addition, when the resin component other than the polyamide resin (A) such as an impact modifier, the compound (B), the phosphorus-containing compound (C) and other additives are contained, the polyamide resin ( The mass of components other than A) or the polyamide resin (A) is measured, and the content of the polyamide resin (A) in the polyamide resin composition for laser welding or its molded product is calculated.

  On the other hand, by subjecting the polyamide resin composition for laser welding or its molded product to dry ashing decomposition in the presence of sodium carbonate, or wet decomposition in sulfuric acid / nitric acid / perchloric acid system or sulfuric acid / hydrogen peroxide system, Phosphorus is regular phosphoric acid. Next, orthophosphoric acid is reacted with molybdate in a 1 mol / L sulfuric acid solution to form phosphomolybdic acid, which is reduced with hydrazine sulfate, and the absorbance of the resulting heteropolyblue at 830 nm is measured with an absorptiometer (calibration curve). The phosphorus content in the polyamide resin composition for laser welding is calculated by colorimetric quantification. By dividing the phosphorus content calculated by colorimetric determination by the previously calculated polyamide resin content, the phosphorus atom equivalent concentration for the polyamide resin can be obtained.

  Examples of the phosphorus-containing compound (C) include phosphite compounds, phosphate compounds, phosphonite compounds, phosphonate compounds, phosphinite compounds, and phosphinate compounds. Two or more of these may be contained.

  Examples of the phosphite compound include phosphorous acid, phosphorous acid alkyl ester, phosphorous acid aryl ester, and metal salts thereof. The alkyl ester or aryl ester may be a monoester, may have a plurality of ester bonds such as a diester or triester, and so on. Specifically, phosphorous acid, trimethyl phosphite, triethyl phosphite, triphenyl phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phosphite, Examples thereof include bis (2,4-di-tert-butylphenyl) pentaerythritol-di-phosphite and metal salts thereof. The metal salt will be described later.

  Examples of the phosphate compound include phosphoric acid, phosphoric acid alkyl ester, phosphoric acid aryl ester, and metal salts thereof. Specific examples include phosphoric acid, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, and metal salts thereof.

  Examples of the phosphonite compound include phosphonous acid, phosphonous acid alkyl ester, phosphonous aryl ester, alkylated phosphonous acid, arylated phosphonous acid, their alkyl ester or aryl ester, and metal salts thereof. Can be mentioned. Specifically, phosphonous acid, dimethyl phosphite, diethyl phosphonite, diphenyl phosphite, methyl phosphonous acid, ethyl phosphonous acid, propyl phosphonous acid, isopropyl phosphonous acid, butyl phosphonous acid, phenyl Phosphorous acid, tetrakis (2,4-di-t-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite, tetrakis (2,4-di-t-butyl-5-methyl) Phenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite, alkyl esters or aryl esters thereof, and metal salts thereof.

  Examples of the phosphonate compound include phosphonic acid, phosphonic acid alkyl ester, phosphonic acid aryl ester, alkylated phosphonic acid or arylated phosphonic acid, their alkyl ester or aryl ester, and metal salts thereof. Specifically, dimethyl phosphonate, diethyl phosphonate, diphenyl phosphonate, methyl phosphonic acid, ethyl phosphonic acid, propyl phosphonic acid, isopropyl phosphonic acid, butyl phosphonic acid, phenyl phosphonic acid, benzyl phosphonic acid, tolyl phosphonic acid, xylyl Examples thereof include phosphonic acid, biphenylphosphonic acid, naphthylphosphonic acid, anthrylphosphonic acid, alkyl esters or aryl esters thereof, and metal salts thereof.

  Examples of the phosphinite compound include phosphinic acid, phosphinic acid alkyl ester, phosphinic acid aryl ester, alkylated phosphinic acid, arylated phosphinic acid, their alkyl or aryl esters, and metal salts thereof. It is done. Specifically, phosphinic acid, methyl phosphite, ethyl phosphite, phenyl phosphite, methyl phosphinic acid, ethyl phosphinic acid, propyl phosphinic acid, isopropyl phosphinic acid, butyl phosphinic acid, phenyl Examples include phosphinic acid, dimethylphosphinic acid, diethylphosphinic acid, dipropylphosphinic acid, diisopropylphosphinic acid, dibutylphosphinic acid, diphenylphosphinic acid, alkyl esters or aryl esters thereof, and metal salts thereof. It is done.

  Examples of the phosphinate compound include hypophosphorous acid, hypophosphorous alkyl ester, hypophosphorous aryl ester, alkylated hypophosphorous acid, arylated hypophosphorous acid, their alkyl ester or aryl ester, and And metal salts thereof. Specifically, methyl phosphinate, ethyl phosphinate, phenyl phosphinate, methylphosphinic acid, ethylphosphinic acid, propylphosphinic acid, isopropylphosphinic acid, butylphosphinic acid, phenylphosphinic acid, tolylphosphinic acid, xylylphosphinic acid, Biphenylylphosphinic acid, dimethylphosphinic acid, diethylphosphinic acid, dipropylphosphinic acid, diisopropylphosphinic acid, dibutylphosphinic acid, diphenylphosphinic acid, ditolylphosphinic acid, dixylphosphinic acid, dibiphenylylphosphinic acid, naphthylphosphinic acid, Anthryl phosphinic acid, 2-carboxyphenyl phosphinic acid, alkyl or aryl esters thereof, and metal salts thereof can be mentioned.

  Among these, phosphite compounds and phosphinate compounds are preferable, and these may be hydrates. It is a further preferred embodiment that it contains at least one selected from the group consisting of phosphorous acid, hypophosphorous acid and metal salts thereof. By including such a compound, it is excellent in the effect of promoting the condensation reaction between the polyamide resin (A) and the compound (B), and further improves the weldability, mechanical strength and dimensional stability of the obtained molded product. Can do.

  Examples of the metal constituting the metal salt include alkali metals such as lithium, sodium, and potassium, and alkaline earth metals such as magnesium, calcium, and barium. Among these, sodium and calcium are preferably used.

  As metal salts of phosphorous acid or hypophosphorous acid, specifically, lithium phosphite, sodium phosphite, potassium phosphite, magnesium phosphite, calcium phosphite, barium phosphite, hypophosphorous acid Examples thereof include lithium, sodium hypophosphite, potassium hypophosphite, magnesium hypophosphite, calcium hypophosphite, and barium hypophosphite. Among these, sodium metal salts such as sodium hypophosphite and sodium phosphite, and calcium metal salts such as calcium phosphite and calcium hypophosphite are more preferable. Condensation reaction between polyamide resin (A) and compound (B) The weldability, mechanical strength and dimensional stability of the resulting molded product can be further improved.

  In the embodiment of the present invention, the compound (B) has a hydroxyl group, an epoxy group and / or a carbodiimide group, and the number of hydroxyl groups in one molecule is the sum of the number of epoxy groups and carbodiimide groups in one molecule. Of the compound (hereinafter, sometimes referred to as “compound (B ′)” for distinction). Since the amino terminal group and carboxyl terminal group of the polyamide resin (A) react with the hydroxyl group, epoxy group and / or carbodiimide group of the compound (B ′) compound, the reactivity between the polyamide resin (A) and the compound (B ′) The dispersibility of the compound (B ′) in the polyamide resin composition can be further improved, and the weldability, mechanical strength, and dimensional stability of the obtained molded product can be improved.

  Moreover, by making the number of hydroxyl groups in one molecule a compound (B ′) larger than the sum of the number of epoxy groups and carbodiimide groups in one molecule, embrittlement due to the formation of an excessive crosslinked structure is suppressed, The weldability, mechanical strength and dimensional stability of the obtained molded product can be improved. Furthermore, a molded article having excellent heat aging resistance can be obtained. The cause of this is not clear, but the polyamide resin (A) has a low molecular weight when the molded product made of the laser-welded polyamide resin composition is heated in the atmosphere, but the polyamide resin increases at that time. A compound in which the carboxyl end group of (A), the hydroxyl group of compound (B ′), and the epoxy group and / or carbodiimide group react to suppress the lowering of the molecular weight of the polyamide resin (A) and can retain heat aging resistance. I think.

In the case of a low molecular compound, the number of hydroxyl groups in one molecule of the compound (B ′) specifies the structural formula of the compound by an ordinary analysis method (for example, a combination of NMR, FT-IR, GC-MS, etc.) Can be calculated. In the case of a condensate, the number of hydroxyl groups can be determined by the following formula (2) by calculating the number average molecular weight and the hydroxyl value of the compound (B ′). The number average molecular weight and the hydroxyl value of the compound (B ′) can be calculated by the method described above.
Number of hydroxyl groups in one molecule = (number average molecular weight × hydroxyl value) / 56110 (2)
In the case of a low molecular weight compound, the number of epoxy groups or carbodiimide groups in one molecule of the compound (B ′) is determined by the structure of the compound by a usual analysis method (for example, a combination of NMR, FT-IR, GC-MS, etc.). The formula can be identified and calculated. In the case of the condensate, the number of epoxy groups or carbodiimide groups can be calculated by dividing the number average molecular weight of the compound (B ′) by the epoxy equivalent or carbodiimide equivalent.

Epoxy equivalent is obtained by dissolving compound (B ′) in hexafluoroisopropanol, adding acetic acid and tetraethylammonium bromide / acetic acid solution, dissolving 0.1N perchloric acid as titrant and crystal violet as indicator. It can be calculated by the following formula (3) from the titration amount when the color of the liquid changes from purple to blue-green.
Epoxy equivalent [g / eq] = W / ((FG) × 0.1 × f × 0.001) (3)
F: amount of 0.1N perchloric acid used for titration [ml], G: amount of 0.1N perchloric acid used for titration of blank [ml], f: 0.1N perchloric acid Acid factor, W: sample weight [g]
The carbodiimide equivalent can be calculated by the following method. The compound (B ′) and potassium ferrocyanide as an internal standard substance are dry-blended and hot-pressed at about 200 ° C. for 1 minute to produce a sheet. Thereafter, the infrared absorption spectrum of the sheet is measured by a transmission method using an infrared spectrophotometer. The measurement conditions are a resolution of 4 cm ⁻¹ and the number of integrations of 32. In the infrared absorption spectrum of the transmission method, the absorbance is inversely proportional to the sheet thickness, so the peak intensity of the carbodiimide group is normalized using the internal standard peak. There is a need. A value obtained by dividing the absorbance of the carbodiimide group-derived peak appearing near 2140 cm ^{−1 by} the absorbance of the CN group absorption peak of potassium ferrocyanide appearing near 2100 cm ⁻¹ is calculated. In order to calculate the carbodiimide equivalent from this value, IR measurement is performed using a sample whose carbodiimide equivalent is known in advance, and a calibration curve is created using the ratio of the absorbance of the peak derived from the carbodiimide group and the absorbance of the internal standard peak. The absorbance ratio of (B ′) is substituted into the calibration curve, and the carbodiimide equivalent is calculated. In addition, aliphatic polycarbodiimide (manufactured by Nisshinbo Co., Ltd., “Carbodilite” (registered trademark) LA-1, carbodiimide equivalent 247 g / mol), aromatic polycarbodiimide (manufactured by Rhein Chemie, “Stabakuzol” (registered trademark)) ) P, carbodiimide equivalent 360 g / mol).

  It is sufficient that it is contained as a compound (B ′) in the polyamide resin composition for laser welding. For example, the compound (B) and an epoxy group and / or carbodiimide group-containing compound (b) (hereinafter referred to as compound (b) )) May be individually added to the polyamide resin (A) to form the compound (B ′) in the polyamide resin composition, and the compound (B ′) obtained by reacting these in advance may be used. The compound (B ′) obtained by reacting these in advance can be blended with the polyamide resin (A), and the compound (B ′) can be blended with the polyamide resin (A). It is more compatible and can improve weldability, mechanical strength, dimensional stability, and heat aging resistance. That is, the compound (B) and the epoxy group and / or carbodiimide group-containing compound (b) are reacted in advance to form a multi-branch having the epoxy group and / or carbodiimide group-containing compound (b) as a linking point. A compound (B ′) having a structure is formed, and since such a compound (B ′) has a multi-branched structure, the self-aggregation force is further reduced, and the reactivity and compatibility with the polyamide resin (A) are reduced. In addition, since the melt viscosity of the compound having a multi-branched structure is improved, the dispersibility of the compound (B ′) in the polyamide resin composition is further improved.

  In the embodiment of the present invention, when the compound (B ′) is a reaction product of the compound (B) and the epoxy group and / or carbodiimide group-containing compound (b), the reaction rate between the hydroxyl group and the epoxy group or carbodiimide group Is preferably 3 to 95% (3% to 95%). When the reaction rate is 3% or more, the degree of branching of the compound (B ′) can be increased, the self-cohesion force can be decreased, the reactivity with the polyamide resin (A) can be increased, and the weldability and mechanical strength can be increased. Further, dimensional stability and heat aging resistance are further improved. The reaction rate is more preferably 10% or more, and further preferably 20% or more.

  On the other hand, when the reaction rate is 95% or less, an epoxy group or a carbodiimide group can be appropriately left, and the reactivity with the polyamide resin (A) can be increased. The reaction rate is more preferably 90% or less, and further preferably 70% or less. Further, the reaction rate of the compound (B ′) can be further increased by including the phosphorus-containing compound (C), and the weldability, mechanical strength, and heat aging resistance are further improved.

And a hydroxyl group, the reaction of the epoxy groups or carbodiimide groups, the compound (B '), dissolved in a solvent (e.g., deuterated dimethyl sulfoxide, deuterated hexafluoroisopropanol), in the case of epoxy groups, ¹ H For the peak derived from the epoxy ring by -NMR measurement, the amount of decrease before and after the reaction with the compound (B) was determined. In the case of a carbodiimide group, the peak derived from the carbodiimide group by ¹³ C-NMR measurement It can calculate by calculating | requiring the reduction | decrease amount before and behind reaction. The reaction rate can be determined by the following formula (4).
Reaction rate (%) = {1- (e / d)} × 100 (4)
(In the above formula (4), d represents the peak area of the dry blend of the (B) compound and (b) the epoxy group and / or carbodiimide group-containing compound, and e represents the peak area of the compound (B ′). Represents.)
As an example, the ¹ H-NMR spectrum of a dry blend of dipentaerythritol and bisphenol A type epoxy resin (“jER” (registered trademark) 1004 manufactured by Mitsubishi Chemical Corporation) at a mass ratio of 3: 1 is shown in FIG. Shown in In addition, FIG. 2 shows the ¹ H-NMR spectrum of the (B′-4) compound and / or its condensate obtained in Reference Example 5 described later. Deuterated dimethyl sulfoxide was used as a solvent, the sample amount was 0.035 g, and the solvent amount was 0.70 ml. Reference numeral 1 indicates a solvent peak.

From the ¹ H-NMR spectrum shown in FIG. 1, the sum of the peak areas derived from the epoxy ring appearing near 2.60 ppm and 2.80 ppm is obtained, and the sum of the peak areas shown in FIG. The reaction rate is calculated according to (4). At this time, the peak area is normalized by the area of the peak of the benzene ring of the epoxy resin that does not contribute to the reaction.

  In addition to the phosphorus-containing compound (C), a catalyst that promotes the reaction between the hydroxyl group and the epoxy group and / or carbodiimide group may be added. The addition amount of the catalyst is preferably 0 to 1 part by mass with respect to 100 parts by mass in total of the compound (B) and (b) the epoxy group and / or carbodiimide group-containing compound, and 0.01 to 0.3 It is a more preferable aspect that it is a mass part.

  Examples of the catalyst that promotes the reaction between the hydroxyl group and the epoxy group include catalysts such as phosphines, imidazoles, amines, and diazabicyclos. Specific examples of the phosphine catalyst include triphenylphosphine (TPP). Specific examples of the imidazole catalyst include 2-heptadecylimidazole (HDI), 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-isobutyl-2-methylimidazole. . Specific examples of amine catalysts include N-hexadecylmorpholine (HDM), triethylenediamine, benzyldimethylamine (BDMA), tributylamine, diethylamine, triethylamine, 1,8-diazabicyclo (5,4,0) -undecene. -7 (DBU), 1,5-diazabicyclo (4,3,0) -nonene-5 (DBN), trisdimethylaminomethylphenol, tetramethylethylenediamine, N, N-dimethylcyclohexylamine, and 1,4-diazabicyclo -(2,2,2) -octane (DABCO) and the like.

  Examples of the catalyst for promoting the reaction between the hydroxyl group and the carbodiimide group include trialkyl lead alkoxide, borohydrofluoric acid, zinc chloride, and sodium alkoxide.

  When the epoxy group and / or carbodiimide group-containing compound (b) preferably used in the embodiment of the present invention has an epoxy group and a carbodiimide group in one molecule, it has two or more in total of the epoxy group and the carbodiimide group. Is preferable, more preferably 4 or more, and even more preferably 6 or more. When one molecule has an epoxy group or a carbodiimide group, it preferably has two or more of any functional groups, more preferably four or more, and even more preferably six or more.

  Since the epoxy group and the carbodiimide group are excellent in compatibility with the polyamide resin (A), the compound having two or more epoxy and / or carbodiimide groups in one molecule is selected from the polyamide resin (A) and the compound (B ′ ) Is considered to have an effect of increasing the compatibility. The epoxy group and / or carbodiimide group-containing compound (b) may be a low molecular compound or may be used as a polymer.

  The number of epoxy groups or carbodiimide groups in one molecule of the epoxy group and / or carbodiimide group-containing compound (b) is the usual analytical method (for example, NMR, FT-IR, GC-MS, etc.) The structural formula of the compound can be specified and calculated by a combination of In the case of a condensate, the number of epoxy groups or carbodiimide groups can be calculated by dividing the number average molecular weight of the (b) epoxy group and / or carbodiimide group-containing compound by the epoxy equivalent or carbodiimide equivalent. The epoxy equivalent and the carbodiimide equivalent can be calculated by the method described above.

  Specific examples of the epoxy group-containing compound include epichlorohydrin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, and glycidyl group-containing vinyl system A polymer etc. can be illustrated. Two or more of these may be used.

  Examples of the glycidyl ether type epoxy resin include a resin produced from epichlorohydrin and bisphenol A, a resin produced from epichlorohydrin and bisphenol F, and a phenol novolac type epoxy resin obtained by reacting a novolak resin with epichlorohydrin. , Orthocresol novolac type epoxy resin, so-called brominated epoxy resin derived from epichlorohydrin and tetrabromobisphenol A, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol polyglycidyl ether, etc. .

  As glycidyl ester type epoxy resins, epoxy resins produced from epichlorohydrin and phthalic acid, tetrahydrophthalic acid, p-oxybenzoic acid or dimer acid, trimesic acid triglycidyl ester, trimellitic acid triglycidyl ester And pyromellitic acid tetraglycidyl ester and the like.

  As the glycidylamine type epoxy resin, an epoxy resin produced from epichlorohydrin and aniline, diaminodiphenylmethane, p-aminophenol, metaxylylenediamine or 1,3-bis (aminomethyl) cyclohexane, tetraglycidylaminodiphenylmethane , Triglycidyl-paraaminophenol, triglycidyl-metaaminophenol, tetraglycidylmetaxylenediamine, tetraglycidylbisaminomethylcyclohexane, triglycidyl cyanurate, and triglycidyl isocyanurate.

  Examples of the alicyclic epoxy resin include compounds having a cyclohexene oxide group, a tricyclodecene oxide group, and a cyclopentene oxide group. Examples of the heterocyclic epoxy resin include an epoxy resin produced from epichlorohydrin and hydantoin or isocyanuric acid.

  Examples of the glycidyl group-containing vinyl polymer include a polymer obtained by radical polymerization of a raw material monomer that forms a glycidyl group-containing vinyl unit. Specific examples of the raw material monomer for forming the glycidyl group-containing vinyl-based unit include glycidyl (meth) acrylate, glycidyl ester of unsaturated monocarboxylic acid such as glycidyl p-styrylcarboxylate, maleic acid, itaconic acid and the like. Examples thereof include monoglycidyl ester or polyglycidyl ester of saturated polycarboxylic acid, allyl glycidyl ether, 2-methylallyl glycidyl ether, and unsaturated glycidyl ether such as styrene-4-glycidyl ether.

  Examples of commercially available epoxy group-containing compounds include polyglycidyl ether compounds that are low molecular polyfunctional epoxy compounds (for example, “SR-TMP” manufactured by Sakamoto Pharmaceutical Co., Ltd., “Denacol” manufactured by Nagase ChemteX Corporation). (Registered trademark) EX-521 ", etc.), polyfunctional epoxy compounds containing polyethylene as a main component (for example," "Bond Fast" (registered trademark) E "manufactured by Sumitomo Chemical Co., Ltd.), Functional epoxy compounds (for example, “Reseda” GP-301 manufactured by Toagosei Co., Ltd. “ARUFON” UG-4000 manufactured by Toagosei Co., Ltd., manufactured by Mitsubishi Rayon Co., Ltd. "" Methbrene "(registered trademark) KP-7653", etc.), a polyfunctional epoxy compound mainly composed of an acrylic / styrene copolymer (for example, "" manufactured by BASF oncryl "(registered trademark) -ADR-4368", "ARUFON" (registered trademark) UG-4040 "manufactured by Toagosei Co., Ltd.), a polyfunctional epoxy compound mainly composed of a silicone-acrylic copolymer (for example, , "" Methbrene "(registered trademark) S-2200", etc.), polyfunctional epoxy compounds mainly composed of polyethylene glycol (for example, "Epiol" (registered trademark) "E-1000" manufactured by NOF Corporation)) Bisphenol A type epoxy resin (for example, “jER” (registered trademark) “1004” manufactured by Mitsubishi Chemical Corporation), and novolak phenol type modified epoxy resin (for example, “EPPN” (registered by Nippon Kayaku Co., Ltd.)) Trademark) “201”).

  Examples of the carbodiimide group-containing compound include dicarbodiimides such as N, N′-diisopropylcarbodiimide, N, N′-dicyclohexylcarbodiimide, N, N′-di-2,6-diisopropylphenylcarbodiimide, and poly (1,6-hexa). Methylene carbodiimide), poly (4,4′-methylenebiscyclohexylcarbodiimide), poly (1,3-cyclohexylenecarbodiimide), poly (1,4-cyclohexylenecarbodiimide), poly (4,4′-dicyclohexylmethanecarbodiimide) , Poly (4,4′-diphenylmethanecarbodiimide), poly (3,3′-dimethyl-4,4′-diphenylmethanecarbodiimide), poly (naphthalenecarbodiimide), poly (p-phenylenecarbodiimide), poly (m-phenol Lencarbodiimide), poly (tolylcarbodiimide), poly (diisopropylcarbodiimide), poly (methyl-diisopropylphenylenecarbodiimide), poly (1,3,5-triisopropylbenzene) polycarbodiimide, poly (1,3,5-triisopropyl) Mention may be made of polycarbodiimides such as benzene) polycarbodiimide, poly (1,5-diisopropylbenzene) polycarbodiimide, poly (triethylphenylenecarbodiimide), and poly (triisopropylphenylenecarbodiimide).

  Examples of commercially available carbodiimide group-containing compounds include “Carbodilite” (registered trademark) manufactured by Nisshinbo Holdings Co., Ltd. and “Stavaxol (registered trademark)” manufactured by Rhein Chemie.

  The molecular weight of the epoxy group and / or carbodiimide group-containing compound (b) preferably used in the embodiment of the present invention is preferably in the range of 800 to 10,000. By setting the molecular weight of the epoxy group and / or carbodiimide group-containing compound (b) to 800 or more, it becomes difficult to volatilize during melt-kneading, and therefore excellent workability. Moreover, since the viscosity at the time of melt kneading of the obtained compound (B ′) can be increased, the compatibility with the polyamide resin (A) becomes higher, and the weldability, mechanical strength, dimensional stability and heat aging resistance are improved. More improved. The molecular weight of the epoxy group and / or carbodiimide group-containing compound (b) is more preferably 1000 or more, and further preferably 2000 or more. By setting the molecular weight of the epoxy group and / or carbodiimide group-containing compound (b) to 2000 or more, the wet heat treatment is performed for 24 hours in a constant temperature and humidity chamber set in an environment of, for example, 60 ° C. and 95% RH. In this case, bleeding out of the compound (B ′) to the surface layer of the molded product can be further suppressed, and the weldability can be further improved.

  On the other hand, when the molecular weight of the epoxy group and / or carbodiimide group-containing compound (b) is 10000 or less, the viscosity at the time of melt kneading of the resulting compound (B ′) can be moderately suppressed, and thus the processability is excellent. . Further, the compatibility between the polyamide resin (A) and the compound (B ′) can be kept high. The molecular weight of the epoxy group and / or carbodiimide group-containing compound (b) is more preferably 8000 or less.

  The molecular weight of the epoxy group and / or carbodiimide group-containing compound (b) can be calculated by specifying the structural formula of the compound by an ordinary analysis method (for example, a combination of NMR, FT-IR, GC-MS, etc.). . Moreover, the weight average molecular weight is used as the molecular weight when the epoxy group and / or carbodiimide group-containing compound is a condensate. The weight average molecular weight (Mw) can be calculated using gel permeation chromatography (GPC). Specifically, when a solvent in which the compound is dissolved, for example, hexafluoroisopropanol is used as a mobile phase, polymethyl methacrylate (PMMA) is used as a standard substance, and the column is matched to the solvent. For example, when hexafluoroisopropanol is used, The weight average molecular weight can be measured using a differential refractometer as a detector using “Shodex GPC HFIP-806M” and / or “Shodex GPC HFIP-LG” manufactured by Shimadzu LLC.

  The epoxy group and / or carbodiimide group-containing compound (b) preferably used in the embodiment of the present invention is solid at a temperature of 25 ° C. or a liquid having a viscosity of 200 mPa · s or more at a temperature of 25 ° C. It is preferable. In that case, it becomes easy to make the viscosity at the time of melt kneading of the obtained compound (B ′) within a desired range, the compatibility between the polyamide resin (A) and the compound (B ′) becomes higher, the weldability, Mechanical strength, dimensional stability and heat aging resistance are further improved.

  The value obtained by dividing the molecular weight by the number of functional groups in one molecule, which is an index indicating the functional group concentration of the epoxy group and / or carbodiimide group-containing compound (b) preferably used in the embodiment of the present invention, is 50 to 3000. It is preferable that Here, the number of functional groups refers to the total number of epoxy groups and carbodiimide groups. The smaller the value, the higher the functional group concentration. By setting it to 50 or more, gelation of the compound (B ′) due to excessive reaction can be suppressed, and the polyamide resin (A) and the compound (B ′) are suppressed. ) Increase moderately, so that the weldability, mechanical strength, dimensional stability and heat aging resistance can be improved. The value obtained by dividing the molecular weight of the epoxy group and / or carbodiimide group-containing compound (b) by the number of functional groups in one molecule is more preferably 100 or more.

  On the other hand, by dividing the molecular weight of the epoxy group and / or carbodiimide group-containing compound (b) by the number of functional groups in one molecule to 3000 or less, the polyamide resin (A) and the compound (B ′) The reaction can be sufficiently secured, and the weldability, mechanical strength, dimensional stability, and heat aging resistance can be further improved. The value obtained by dividing the molecular weight of the epoxy group and / or carbodiimide group-containing compound (b) by the number of functional groups in one molecule is more preferably 2000 or less, more preferably 1000 or less, and 300 or less. This is a more preferable embodiment.

  When the compound (B ′) is produced by reacting the compound (B) with the epoxy group and / or carbodiimide group-containing compound (b), the compounding ratio of these compounds is determined based on the hydroxyl groups in one molecule of the compound (B ′). It is preferable to blend these compounds so that the number is larger than the sum of the number of epoxy groups and carbodiimide groups in one molecule. The epoxy group and carbodiimide group are excellent in reactivity with the end group of the polyamide resin (A) as compared with the hydroxyl group. Therefore, by increasing the number of hydroxyl groups in one molecule of the compound (B ′) more than the sum of the number of epoxy groups and carbodiimide groups in one molecule, embrittlement due to the formation of an excessive cross-linked structure is suppressed. Further, weldability, mechanical strength, dimensional stability and heat aging resistance can be further improved.

  In the embodiment of the present invention, the compound (B ′) is preferably a compound having a structure represented by the following general formula (1) and / or a condensate thereof.

(In the general formula (1), X ^{1 to} X ⁶ may be the same or different and each represents OH, CH ₃ or OR, provided that the sum of the number of OH and OR is 3 or more, and The number is 3 or more, and R represents an organic group having an epoxy group or a carbodiimide group, and n represents a range of 0 to 20.)
R in the above general formula (1) represents an organic group having an epoxy group or an organic group having a carbodiimide group. Examples of the organic group having an epoxy group include an epoxy group, a glycidyl group, a glycidyl ether type epoxy group, a glycidyl ester type epoxy group, a glycidyl amine type epoxy group, a hydrocarbon group substituted with an epoxy group or a glycidyl group, and an epoxy group. And a heterocyclic group substituted with a group or a glycidyl group. Examples of the organic group having a carbodiimide group include an alkyl carbodiimide group, a cycloalkyl carbodiimide group, and an arylalkyl carbodiimide group.

  In the general formula (1), n represents a range of 0-20. When n is 20 or less, the plasticization of the polyamide resin (A) is suppressed, and the weldability and mechanical strength can be further improved. n is more preferably 4 or less, and the weldability and mechanical strength can be further improved. On the other hand, n is more preferably 1 or more, the molecular mobility of the compound (B ′) can be increased, and the compatibility with the polyamide resin (A) can be further improved.

  The sum of the numbers of OH and OR in the general formula (1) is preferably 3 or more. Thereby, it is excellent in compatibility with the polyamide resin (A), and the weldability, mechanical strength, dimensional stability and heat aging resistance of the obtained molded product can be further improved. Here, the sum of the number of OH and OR is calculated by specifying the structural formula of the compound by a usual analysis method (for example, a combination of NMR, FT-IR, GC-MS, etc.) in the case of a low molecular compound. be able to.

In the case of a condensate, the number of OH can be obtained from the following formula (2) by calculating the number average molecular weight and hydroxyl value of the compound having the structure represented by the general formula (1) and / or the condensate thereof. .
-Number of OH in general formula (1) = (number average molecular weight x hydroxyl value) / 56110 (2)
In the case of a condensate, the number of ORs is calculated by a value obtained by dividing the number average molecular weight of the compound having the structure represented by the general formula (1) and / or the condensate by an epoxy equivalent or a carbodiimide equivalent. Can do. The number average molecular weight of the compound having the structure represented by the general formula (1) and / or the condensate thereof can be calculated using a gel permeation chromatograph (GPC). Specifically, it can be calculated by the following method. A solvent in which the compound having the structure represented by the general formula (1) and / or the condensate thereof is dissolved, for example, hexafluoroisopropanol is used as a mobile phase, and polymethyl methacrylate (PMMA) is used as a standard substance. The column is matched to the solvent. For example, when hexafluoroisopropanol is used, “Shodex GPC HFIP-806M” and / or “Shodex GPC HFIP-LG” manufactured by Shimadzu GL Corporation is used as a detector. The number average molecular weight can be measured using a differential refractometer.

  The compound (B ′) having the structure represented by the general formula (1) can appropriately introduce a crosslinked structure and has a smaller self-aggregation force, and (A) improved reactivity and compatibility with the polyamide resin. And excellent in weldability, mechanical strength, dimensional stability, and heat aging resistance.

  The hydroxyl value of the compound (B) and the compound (B ′) used in the embodiment of the present invention is preferably 100 to 2000 mgKOH / g. By ensuring that the hydroxyl value of the compound (B) and the compound (B ′) is 100 mgKOH / g or more, a sufficient reaction amount between the polyamide resin (A) and the compound (B) or the compound (B ′) is secured. Therefore, weldability, mechanical strength, dimensional stability, and heat aging resistance can be further improved. The hydroxyl value of the compound (B) and the compound (B ′) is more preferably 300 mgKOH / g or more, further preferably 600 mgKOH / g or more. On the other hand, by setting the hydroxyl value of the compound (B) and the compound (B ′) to 2000 mgKOH / g or less, the reactivity between the polyamide resin (A) and the compound (B) or the compound (B ′) is moderately improved. Weldability, mechanical strength, dimensional stability and heat aging resistance can be improved. Moreover, the gelation by excess reaction can be suppressed by making the hydroxyl value of a compound (B) and a compound (B ') into 2000 mgKOH / g or less. The hydroxyl value of the compound (B) and the compound (B ′) is more preferably 1800 mgKOH / g or less. Here, the hydroxyl value of the compound (B) and the compound (B ′) is determined by acetylating the compound (B) and the compound (B ′) with a mixed solution of acetic anhydride and anhydrous pyridine, and adding it to ethanolic potassium hydroxide. It can be determined by titrating with a solution.

  In the embodiment of the present invention, the degree of branching of the compound (B) and the compound (B ′) is preferably 0.05 to 0.70. The degree of branching is a numerical value representing the degree of branching in the compound. A linear compound has a degree of branching of 0, and a completely branched dendrimer has a degree of branching of 1. As this value is larger, a crosslinked structure can be introduced into the polyamide resin composition for composite molded articles, and the weldability, mechanical strength and dimensional stability of the molded article can be improved. By setting the degree of branching to 0.05 or more, the crosslinked structure in the polyamide resin composition for composite molded articles is sufficiently formed, and the weldability, mechanical strength, dimensional stability, and heat aging resistance can be further improved. . The degree of branching is more preferably 0.10 or more.

On the other hand, by setting the degree of branching to 0.70 or less, the crosslinked structure in the polyamide resin composition for composite molded articles is moderately suppressed, and the compound (B) and compound (B ′) in the polyamide resin composition for composite molded articles are suppressed. ) Can be further improved, and weldability, mechanical strength, dimensional stability and heat aging resistance can be further improved. The degree of branching is more preferably 0.35 or less. The degree of branching is defined by the following formula (5).
Branch degree = (D + T) / (D + T + L) (5)
(In the above formula (5), D represents the number of dendritic units, L represents the number of linear units, and T represents the number of terminal units. The above D, T, and L are peak shifts measured by ¹³ C-NMR. D is derived from a tertiary or quaternary carbon atom, T is derived from a primary carbon atom that is a methyl group, and L is a primary carbon atom. Or derived from secondary carbon atoms excluding T).

  The compound (B) and the compound (B ′) used in the embodiment of the present invention can contain other reactive functional groups in addition to the hydroxyl group. Examples of other functional groups include aldehyde groups, sulfo groups, isocyanate groups, oxazoline groups, oxazine groups, ester groups, amide groups, silanol groups, and silyl ether groups.

  The molecular weight of the compound (B) and the compound (B ′) used in the embodiment of the present invention is preferably in the range of 50 to 10,000. When the molecular weights of the compound (B) and the compound (B ′) are 50 or more, they are difficult to volatilize during melt-kneading, and thus processability is excellent. The molecular weight of the compound (B) and the compound (B ′) is preferably 150 or more, more preferably 200 or more.

  On the other hand, if the molecular weights of the compound (B) and the compound (B ′) are 10,000 or less, the compatibility between the compound (B) or the compound (B ′) and the polyamide resin (A) becomes higher. The effect is more prominent. The molecular weights of the compound (B) and the compound (B ′) are preferably 6000 or less, more preferably 4000 or less, and still more preferably 800 or less.

  The molecular weights of the compound (B) and the compound (B ′) can be calculated by specifying the structural formula of the compound by an ordinary analysis method (for example, a combination of NMR, FT-IR, GC-MS, etc.). In addition, when the compound (B) and the compound (B ′) are condensates, the weight average molecular weight is used as the molecular weight. The weight average molecular weight (Mw) can be calculated using gel permeation chromatography (GPC). Specifically, when a solvent in which the compound is dissolved, for example, hexafluoroisopropanol is used as a mobile phase, polymethyl methacrylate (PMMA) is used as a standard substance, and the column is matched to the solvent. For example, when hexafluoroisopropanol is used, Shimadzu Using “Shodex GPC HFIP-806M” and / or “Shodex GPC HFIP-LG” manufactured by GL Corp., the weight average molecular weight can be measured using a differential refractometer as a detector.

  The polyamide resin composition for laser welding of the present invention can further contain a copper compound. In addition to coordination with the amide group of the polyamide resin (A), the copper compound is considered to coordinate with the hydroxyl group and hydroxide ion of the compound (B) or compound (B ′). For this reason, it is considered that the copper compound has an effect of increasing the compatibility between the polyamide resin (A) and the compound (B) or the compound (B ′).

  The polyamide resin composition for laser welding of the present invention can further contain a potassium compound. A potassium compound suppresses the liberation and precipitation of copper. For this reason, it is thought that a potassium compound has an effect which accelerates | stimulates reaction with a copper compound, a compound (B) or a compound (B '), and a polyamide resin (A).

  Examples of copper compounds include copper chloride, copper bromide, copper iodide, copper acetate, copper acetylacetonate, copper carbonate, copper borofluoride, copper citrate, copper hydroxide, copper nitrate, copper sulfate, and oxalic acid. Examples include copper. Two or more of these can be contained as a copper compound. Among these copper compounds, those commercially available are preferable, and copper halide is preferable. Examples of the copper halide include copper iodide, cuprous bromide, cupric bromide, and cuprous chloride. As the copper halide, copper iodide is particularly preferably used.

  Examples of the potassium compound include potassium iodide, potassium bromide, potassium chloride, potassium fluoride, potassium acetate, potassium hydroxide, potassium carbonate, and potassium nitrate. Two or more of these can be contained as the potassium compound. Of these potassium compounds, potassium iodide is preferably used. By containing a potassium compound, the surface appearance, weather resistance and mold corrosion resistance of the molded product can be improved.

  It is preferable that content (weight basis) of the copper element in the polyamide resin composition for laser welding of this invention is 25-200 ppm. By setting the copper element content to 25 ppm or more, the compatibility between the polyamide resin (A) and the compound (B) or the compound (B ′) is further improved, and the weldability, mechanical strength, and dimensional stability of the molded product are improved. And heat aging resistance can be further improved. The content (weight basis) of copper element in the polyamide resin composition for laser welding is preferably 80 ppm or more.

  On the other hand, by setting the content of the copper element to 200 ppm or less, it is possible to suppress the coloration due to precipitation and liberation of the copper compound, and to further improve the surface appearance of the molded product. In addition, by making the content of copper element 200 ppm or less, it is possible to suppress a decrease in the hydrogen bond strength of the amide group due to excessive coordination bond between the polyamide resin and copper, and to improve the weldability and mechanical strength of the molded product. Can be improved. The content (weight basis) of copper element in the polyamide resin composition for laser welding is preferably 190 ppm or less. In addition, content of the copper element in the polyamide resin composition for laser welding can be made into the above-mentioned desired range by adjusting the compounding quantity of a copper compound suitably.

  The content of the copper element in the polyamide resin composition for laser welding can be determined by the following method. First, the pellets of the polyamide resin composition for laser welding are dried under reduced pressure. The pellet is incinerated for 24 hours in an electric furnace at 550 ° C., concentrated sulfuric acid is added to the incinerated product, and the mixture is heated and wet-decomposed to dilute the decomposition solution. The copper content can be determined by atomic absorption analysis (calibration curve method) of the diluted solution.

  The ratio Cu / K of the copper element content to the potassium element content in the laser welding polyamide resin composition is preferably 0.21 to 0.43. Cu / K is an index representing the degree of suppression of copper precipitation and liberation, and the smaller this value, the more the copper compound and compound (B) or compound (B ′) are suppressed by inhibiting copper precipitation and liberation. And the polyamide resin (A) can be promoted. By setting Cu / K to 0.43 or less, copper precipitation and liberation can be suppressed, and the surface appearance of the molded product can be further improved. In addition, by setting Cu / K to 0.43 or less, the compatibility of the polyamide resin composition for laser welding is also improved, so the weldability, mechanical strength, dimensional stability and heat aging resistance of the molded product are further improved. Can be made.

  On the other hand, by setting Cu / K to 0.21 or more, the dispersibility of the compound containing potassium is improved, and even if it is deliquescent potassium iodide, it is difficult to form a lump, and the effect of suppressing the precipitation and release of copper is improved. As a result, the reaction between the copper compound, the compound (B) or the compound (B ′), and the polyamide resin (A) is sufficiently accelerated, and the weldability, mechanical strength, dimensional stability and heat aging of the molded product are enhanced. Improve sex.

  The potassium element content in the laser welding polyamide resin composition can be determined by the same method as the above copper content.

  The polyamide resin composition for laser welding of the present invention may further contain a filler. As the filler, both organic fillers and inorganic fillers are used. Moreover, as a filler, both a fibrous filler and a non-fibrous filler are used. As the filler, a fibrous filler is preferably used.

  Examples of the fibrous filler include glass fiber, PAN (polyacrylonitrile) -based or pitch-based carbon fiber, stainless steel fiber, metal fiber such as aluminum fiber and brass fiber, organic fiber such as aromatic polyamide fiber, gypsum fiber, Ceramic fiber, asbestos fiber, zirconia fiber, alumina fiber, silica fiber, titanium oxide fiber, silicon carbide fiber, rock wool, potassium titanate whisker, zinc oxide whisker, calcium carbonate whisker, wollastonite whisker, aluminum borate whisker, silicon nitride whisker And fibrous or whisker-like fillers. As the fibrous filler, glass fiber or carbon fiber is particularly preferably used.

  The type of glass fiber as the fibrous filler is generally used for reinforcing the resin, and can be selected from, for example, chopped strands of long fiber type or short fiber type, milled fiber, or the like. The glass fibers are also allowed to be coated or bundled with a thermoplastic resin such as an ethylene / vinyl acetate copolymer or a thermosetting resin such as an epoxy resin. Furthermore, the cross-section of the glass fiber is not limited to a circular, flat gourd, eyebrows, oval, ellipse, rectangle, or similar products. From the viewpoint of reducing the specific warpage of a molded product that is likely to occur in a glass fiber-containing polyamide resin composition, a flat glass fiber having a ratio of the major axis / minor axis of the glass fiber cross section of 1.5 or more is preferable, and the major axis / minor axis The ratio is more preferably 2.0 or more, preferably 10 or less, and more preferably 6.0 or less. When the ratio of major axis / minor axis is less than 1.5, the effect of flattening the cross section is small, and when the ratio is larger than 10, it is difficult to produce the glass fiber itself.

  Examples of non-fibrous fillers include non-swelling silicates such as talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, bentonite, asbestos, alumina silicate, calcium silicate, Li Swellable lamellar silicates represented by swellable mica, such as Na-type Fluorine Teniolite, Na-type Fluorine Teniolite, Na-type Tetrasilicon Fluorine Mica, Li-type Tetrasilicon Fluorine Mica, Silicon Oxide, Magnesium Oxide, Alumina, Silica, Diatomaceous Earth, Zirconium Oxide , Metal oxides such as titanium oxide, iron oxide, zinc oxide, calcium oxide, tin oxide, antimony oxide, metal carbonates such as calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dolomite, hydrotalcite, calcium sulfate, Metal sulfates such as barium sulfate, water Metal hydroxides such as magnesium hydroxide, calcium hydroxide, aluminum hydroxide, basic magnesium carbonate, montmorillonite, beidellite, nontronite, saponite, hectorite, and soconite And various clay minerals such as zirconium phosphate and titanium phosphate, glass beads, glass flakes, ceramic beads, boron nitride, aluminum nitride, silicon carbide, calcium phosphate, carbon black, and graphite.

  In the swellable layered silicate, exchangeable cations existing between layers may be exchanged with organic onium ions, and examples of the organic onium ions include ammonium ions, phosphonium ions, and sulfonium ions. Two or more of these fillers can be contained.

  The above-mentioned filler has a coupling agent (for example, a silane coupling agent or a titanate coupling agent) or a sizing agent (for example, a sizing agent such as carboxylic acid, epoxy, or urethane) on the surface. The mechanical strength and surface appearance of the molded product can be further improved. As the sizing agent, an epoxy sizing agent is preferably used.

  As a method for treating the filler, for example, in the case of treatment with a coupling agent, a method in which the filler is surface-treated with the coupling agent in advance and then melt-kneaded with the polyamide resin is preferably used. Without performing the above, an integral blend method in which a coupling agent is added when the filler and the polyamide resin are melt-kneaded can also be used. The amount of the coupling agent to be treated is preferably 0.05 parts by mass or more, more preferably 0.5 parts by mass or more with respect to 100 parts by mass of the filler. On the other hand, the treatment amount of the coupling agent is preferably 10 parts by mass or less, more preferably 3 parts by mass or less, with respect to 100 parts by mass of the filler.

  In the polyamide resin composition for laser welding of the present invention, the content of the filler is preferably 1 to 150 parts by mass with respect to 100 parts by mass of the polyamide resin (A). If content of a filler is 1 mass part or more, the mechanical strength of a molded article can be improved more. As for content of a filler, it is more preferable that it is 10 mass parts or more, More preferably, it is 20 mass parts or more. On the other hand, if the content of the filler is 150 parts by mass or less, a molded product having superior weldability and dimensional stability can be obtained. The content of the filler is more preferably 80 parts by mass or less, and still more preferably 70 parts by mass or less.

  Furthermore, the polyamide resin composition for laser welding of the present invention can contain a resin other than the polyamide resin and various additives depending on the purpose within a range not impairing the effects of the present invention.

  Specific examples of resins other than polyamide resins include polyester resins, polyolefin resins, modified polyphenylene ether resins, polysulfone resins, polyketone resins, polyetherimide resins, polyarylate resins, polyether sulfone resins, polyether ketone resins, polythioethers. Examples thereof include ketone resins, polyether ether ketone resins, polyimide resins, polyamideimide resins, and tetrafluoropolyethylene resins. When these resins are blended, the content is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, based on 100 parts by mass of the polyamide resin (A) in order to fully utilize the characteristics of the polyamide resin. It is.

  Specific examples of various additives include heat stabilizers other than copper compounds, isocyanate compounds, organic silane compounds, organic titanate compounds, organic borane compounds, epoxy compounds and other coupling agents, polyalkylene oxide oligomers. Compounds, plasticizers such as thioether compounds and ester compounds, crystal nucleating agents such as polyether ether ketone, metal soaps such as montanic acid wax, lithium stearate, aluminum stearate, ethylenediamine, stearic acid, sebacic acid heavy Examples thereof include mold release agents such as condensates and silicone compounds, lubricants, ultraviolet light inhibitors, colorants, flame retardants, impact resistance improvers, and foaming agents. When these additives are contained, the content is preferably 10 parts by mass or less, more preferably 1 part by mass with respect to 100 parts by mass of the polyamide resin (A) in order to fully utilize the characteristics of the polyamide resin. Or less.

  Examples of heat stabilizers other than copper compounds include phenolic compounds, sulfur compounds, and amine compounds. Two or more of these may be used as the heat stabilizer other than the copper compound.

  As the phenolic compound, a hindered phenolic compound is preferably used. In particular, N, N′-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamide) and tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4 ′). -Hydroxyphenyl) propionate] methane and the like are preferably used.

  Examples of sulfur compounds include organic thioacid compounds, mercaptobenzimidazole compounds, dithiocarbamic acid compounds, and thiourea compounds. Among these sulfur compounds, mercaptobenzimidazole compounds and organic thioacid compounds are preferably used.

  In particular, a thioether compound having a thioether structure can be suitably used as a heat stabilizer because it receives oxygen from an oxidized substance and reduces it. Specific examples of thioether compounds include 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis (3-dodecylthiopropionate). ), Pentaerythritol tetrakis (3-laurylthiopropionate) is preferred, and pentaerythritol tetrakis (3-dodecylthiopropionate) and pentaerythritol tetrakis (3-laurylthiopropionate) are more preferably used. The molecular weight of the sulfur compound is usually 200 or more, preferably 500 or more, and the upper limit is usually 3,000.

  As the amine compound, a compound having a diphenylamine skeleton, a compound having a phenylnaphthylamine skeleton, and a compound having a dinaphthylamine skeleton are preferable, and a compound having a diphenylamine skeleton and a compound having a phenylnaphthylamine skeleton are more preferably used. Among these amine compounds, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, N, N′-di-2-naphthyl-p-phenylenediamine and N, N′-diphenyl-p-phenylenediamine Are more preferable, and N, N′-di-2-naphthyl-p-phenylenediamine and 4,4′-bis (α, α-dimethylbenzyl) diphenylamine are particularly preferable.

  As a combination of a sulfur compound or an amine compound, a combination of pentaerythritol tetrakis (3-laurylthiopropionate) and 4,4′-bis (α, α-dimethylbenzyl) diphenylamine is preferable.

  Examples of the method for producing the laser welding polyamide resin composition of the present invention include, as an efficient example, a method in which each raw material is supplied to a known device such as a single screw or twin screw extruder and melt kneaded. it can.

  As a more preferable method for producing the laser welding polyamide resin composition of the present invention, a high-concentration premix is prepared by melt-kneading the polyamide resin (A) and the compound (B) or the compound (B ′) with a twin screw extruder. In addition, a method in which the high-concentration premix is further melt-kneaded with the polyamide resin (A) and the phosphorus-containing compound (C) with a twin screw extruder can be mentioned. To 100 parts by weight of the polyamide resin (A), 10 to 250 parts by weight of the compound (B) or the compound (B ′) is melt-kneaded to prepare a high concentration premix, and the high concentration premix is further added to the polyamide resin ( It is more preferable to melt and knead together with A) and the phosphorus-containing compound (C) with a twin screw extruder. Compared with the case where a high-concentration premix is not prepared, the compatibility between the polyamide resin (A) and the compound (B) or the compound (B ′) is further improved, and the weldability, mechanical strength, and dimensional stability of the resulting molded product are improved. And heat aging resistance are further improved. Moreover, when producing a high concentration premix, the compounding quantity of a compound (B) increases with respect to a polyamide resin (A). In order to suppress a decrease in residence stability, at the time of melt kneading in a twin screw extruder, the compound (B) or the compound (B ′) is supplied from the downstream side of the polyamide resin supply position, and the polyamide resin (A), It is preferable to shorten the kneading time of the compound (B) or the compound (B ′).

  The polyamide resin (A) used in the high concentration premix and the polyamide resin (A) further blended in the high concentration premix may be the same or different.

  The polyamide resin composition thus obtained for laser welding can be formed into a molded product by various known molding methods. Examples of the molding method include injection molding, injection compression molding, extrusion molding, compression molding, blow molding, and press molding.

  The laser light transmitting molded product and the laser light absorbing molded product used in the present invention can also be molded using the molding method described above.

  The composite molded article of the present invention is formed by laser welding a laser light transmissive molded article and a laser light absorptive molded article, and is at least one of the laser light transmissive molded article and the laser light absorptive molded article. Further, a molded product formed by molding the polyamide resin composition for laser welding of the present invention is used. As a more preferable form, a molded product obtained by molding the laser welding polyamide resin composition of the present invention is used for both a laser light transmissive molded product and a laser light absorbing molded product.

  When the laser welding polyamide resin composition of the present invention is not used for one of the laser light transmitting molded product or the laser light absorbing molded product, the resin used for the other is polyamide resin, olefin resin, vinyl resin A thermoplastic resin such as a resin, a styrene resin, an acrylic resin, a polyphenylene ether resin, a polyester resin, a polycarbonate resin, a polyacetal resin, and polyphenylene sulfide is preferable, and particularly compatible with the polyamide resin composition of the present invention for laser welding. From the viewpoint, polyamide resin, polyester resin, polycarbonate resin and polyphenylene sulfide resin are preferably used.

  The laser light absorbing molded product used in the present invention is preferably a molded product further containing a laser light absorbing additive in the polyamide resin composition used in the present invention. It is preferable to contain 0.01-5 mass parts of laser beam absorption additives with respect to 100 mass parts of polyamide resins. Examples of the laser light absorbing additive include inorganic pigments and organic pigments such as carbon black, iron oxide, molybdate orange, and titanium oxide.

  The melting point of the laser light-absorbing molded product molded using the polyamide resin composition for laser welding of the present invention is preferably the same or higher than the melting point of the laser light-transmitting molded product. . By doing so, the heat of the laser light-absorbing molded product melted by the laser irradiation becomes easy to melt the laser light-transmitting molded product, so that the weldability is improved.

  According to the laser welding method of the present invention, a laser light-absorbing molded article is brought into contact with a laser light-absorbing molded article, and the laser light-absorbing molded article is irradiated with a laser from the laser light-transmitting molded article side. In the vicinity of the contact, the laser beam is absorbed to generate heat and melt. Next, the heat is transferred to the laser light transmissive molded product by heat conduction, and the laser light transmissive molded product melts in the vicinity of the contact. As described above, the contact surfaces of the laser-light-absorbing molded product and the laser-light-transmitting molded product are melted, so that both can be integrally welded.

  The laser-light-transmitting molded product molded using the laser welding polyamide resin composition of the present invention preferably has a light transmittance of 15% or more at a wavelength of 940 nm in a molded product having a thickness of 3 mm, more preferably. It is 30% or more, more preferably 40% or more. The thickness of the molded product is preferably 10 mm or less.

  The laser-light-absorbing molded product molded using the laser welding polyamide resin composition of the present invention preferably has a light transmittance of 10% or less at a wavelength of 940 nm in a molded product having a thickness of 3 mm.

  As a laser light source, for example, a gas laser such as an argon laser (510 nm) or a helium-neon laser (630 nm), a liquid laser such as a dye laser (400 to 700 nm), a solid laser such as a YAG laser (1064 nm), or a semiconductor A laser (655 to 980 nm) can be used. Irradiation of these laser light sources may be either continuous irradiation or pulse irradiation.

  The conditions such as the wavelength, output, irradiation diameter, and irradiation speed of the laser light can be set as appropriate. For example, the wavelength of the laser beam is preferably 400 nm or more. When the wavelength is 400 nm or more, it is possible to suppress a decrease in strength due to resin alteration, which is preferable. The output of the laser beam is preferably 10W to 50W. When it is 10 W or more, it becomes easy to ensure sufficient weldability, and when it is 50 W or less, it is possible to suppress a decrease in strength due to resin alteration, which is preferable. The laser beam irradiation speed is preferably 1 mm / sec to 50 mm / sec. When it is 1 mm / sec or more, it is possible to suppress a decrease in strength due to resin alteration, and when it is 50 mm / sec or less, it is easy to ensure sufficient weldability, which is preferable.

  The composite molded article of the present invention can be used for various applications such as automobile parts, electrical / electronic parts, building members, and various containers by taking advantage of its excellent characteristics. The composite molded article of the present invention is, among other things, automobile engine peripheral parts, automobile underhood parts, automobile exterior parts, intake / exhaust system parts, engine cooling water system parts, automobile electrical parts, which require weldability, mechanical strength and dimensional stability. , And electrical / electronic component applications.

  Specifically, engine covers, air intake pipes, timing belt covers, intake manifolds, filler caps, throttle bodies, cooling fan and other automotive engine peripheral parts, cooling fans, radiator tank tops and bases, cylinder head covers, oil pans, Automotive underhood parts such as brake piping, fuel piping tubes, waste gas system parts, front fender, rear fender, fuel lid, door panel, cylinder head cover, door mirror stay, tailgate panel, license garnish, roof rail, engine mount bracket, rear garnish , Rear spoiler, trunk lid, rocker molding, molding, lamp housing, front grill, mud gar Automobile exterior parts such as side bumpers, air intake manifolds, intercooler inlets, turbochargers, exhaust pipe covers, inner bushes, bearing retainers, engine mounts, engine head covers, resonators, and throttle body intake and exhaust system parts, chain covers, Engine cooling water system parts such as thermostat housings, outlet pipes, radiator tanks, oil naters, and delivery pipes, connectors and wire harness connectors, motor parts, lamp sockets, sensor automotive switches such as on-board switches, combination switches, electrical / electronic parts Examples include generators, motors, transformers, current transformers, voltage regulators, rectifiers, resistors, inverters, , Power contacts, switches, breakers, switches, knife switches, other pole rods, motor cases, laptop housings and internal parts, CRT display housings and internal parts, printer housings and internal parts, mobile phones, mobile PCs, Handheld mobile and other portable terminal housings and internal parts, IC and LED compatible housings, capacitor seats, fuse holders, various gears, various cases, cabinets and other electrical components, connectors, SMT compatible connectors, card connectors, jacks, coils , Coil bobbin, sensor, LED lamp, socket, resistor, relay, relay case, reflector, small switch, power supply parts, coil bobbin, condenser, variable capacitor case, optical pickup chassis, Oscillator, various terminal boards, transformer, plug, printed circuit board, tuner, speaker, microphone, headphones, small motor, magnetic head base, power module, Si power module or SiC power module, semiconductor, liquid crystal, FDD carriage, FDD chassis It is preferably used for electronic parts such as motor brush holders, transformer members, parabolic antennas, and computer-related parts.

  Next, the polyamide resin composition and molded product for laser welding according to the present invention will be described more specifically with reference to examples. The characteristic evaluation was performed according to the following method.

[Melting point of polyamide resin]
About 5 mg of polyamide resin was sampled and the melting point of the polyamide resin (A) was measured under the following conditions using a Seiko Instruments robot DSC (differential scanning calorimeter) RDC220 under a nitrogen atmosphere. Next, after raising the melting point of the polyamide resin (A) to 40 ° C. to a molten state, the temperature was lowered to a temperature of 30 ° C. at a temperature lowering rate of 20 ° C./min, and held at a temperature of 30 ° C. for 3 minutes. The temperature (melting point) of the endothermic peak observed when the temperature was raised to the melting point + 40 ° C. at a temperature rising rate of 20 ° C./min was determined.

[Phosphorus atom content with respect to polyamide resin in polyamide resin composition for laser welding]
The pellets obtained in each example and comparative example were dried under reduced pressure at a temperature of 80 ° C. for 12 hours, and the pellets were ashed in an electric furnace at a temperature of 550 ° C. for 24 hours to obtain an inorganic content. Subsequently, the pellet was stirred in DMSO at a temperature of 60 ° C., and additive components other than the polyamide resin were extracted to determine the additive content. Thereafter, the content of the polyamide resin in the composition was determined by subtracting the inorganic and additive weights from the mass of the polyamide resin composition.

  Next, the pellets of the polyamide resin composition for laser welding were wet-decomposed in a sulfuric acid / hydrogen peroxide system to convert phosphorus into normal phosphoric acid, and the decomposition solution was diluted. Next, the orthophosphoric acid is reacted with molybdate in a 1 mol / L sulfuric acid solution to form phosphomolybdic acid, which is reduced with hydrazine sulfate. The phosphorus content in the polyamide resin composition for laser welding was calculated by colorimetric determination using a calibration curve method). The phosphorus atom content relative to the polyamide resin content was determined by dividing the phosphorus content calculated by colorimetric determination by the previously calculated polyamide resin content. U-3000 manufactured by Hitachi, Ltd. was used as the absorptiometer.

[Copper content and potassium content in the polyamide resin composition for laser welding]
The pellets obtained in each example and comparative example were dried under reduced pressure at a temperature of 80 ° C. for 12 hours. The pellet was incinerated for 24 hours in an electric furnace at a temperature of 550 ° C., concentrated sulfuric acid was added to the incinerated product, and the mixture was heated and wet-decomposed to dilute the decomposition solution. The diluted solution was subjected to atomic absorption analysis (calibration curve method) to determine the copper content and the potassium content. AA-6300 manufactured by Shimadzu Corporation was used as the atomic absorption spectrometer.

[Weight average molecular weight and number average molecular weight]
Compound (B), compound (B ′), and 2.5 mg of epoxy group and / or carbodiimide group-containing compound (b) were dissolved in 4 ml of hexafluoroisopropanol (0.005N sodium trifluoroacetate added), respectively. A solution obtained by filtration through a 45 μm filter was used for the measurement. The measurement conditions are as follows.
Apparatus: Gel permeation chromatography (GPC) (manufactured by Waters)
Detector: differential refractometer Waters 410 (manufactured by Waters)
Column: Shodex GPC HFIP-806M (2) + HFIP-LG (Shimadzu GL Corp.)
・ Flow rate: 0.5ml / min
・ Sample injection volume: 0.1 ml
・ Temperature: 30 ℃
-Molecular weight calibration: polymethyl methacrylate.

[Hydroxyl value]
Collect 0.5 g of compound (B) and compound (B ′), add each to a 250 ml Erlenmeyer flask, and then collect 20.00 ml of a solution prepared by adjusting and mixing acetic anhydride and anhydrous pyridine to 1:10 (mass ratio). The flask was placed in the Erlenmeyer flask, attached with a reflux condenser, refluxed for 20 minutes in an oil bath adjusted to a temperature of 100 ° C. with stirring, and then cooled to 30 ° C. Furthermore, 20 ml of acetone and 20 ml of distilled water were added to the above Erlenmeyer flask through a cooler. A phenolphthalein indicator was added thereto, and titrated with a 0.5 mol / L ethanolic potassium hydroxide solution. The hydroxyl value was calculated by the following formula (6) by subtracting the measurement result of the blank (not including the sample) separately measured.
Hydroxyl value [mgKOH / g] = [((BC) × f × 28.05) / S] + E (6)
(In the above formula, B represents the amount [ml] of 0.5 mol / L ethanolic potassium hydroxide solution used for titration, and C represents 0.5 mol / L ethanolic potassium hydroxide used for blank titration. The amount of the solution [ml] is represented, f represents the factor of the 0.5 mol / L ethanolic potassium hydroxide solution, S represents the mass [g] of the sample, and E represents the acid value.)
[Reaction rate between hydroxyl group and epoxy group or carbodiimide group]
0.035 g of the compound (B ′) was dissolved in 0.7 ml of deuterated dimethyl sulfoxide, and in the case of an epoxy group, ¹ H-NMR measurement was performed, and in the case of a carbodiimide group, ¹³ C-NMR measurement was performed. Each analysis condition is as follows.

(1) ¹ H-NMR
・ Device: Nuclear magnetic resonance apparatus (JNM-AL400) manufactured by JEOL Ltd.
・ Solvent: Deuterated dimethyl sulfoxide ・ Observation frequency: OBFRQ 399.65 MHz, OBSET 124.00 KHz, O.BFIN10500.00 Hz
-Accumulation count: 256 times.

(2) ¹³ C-NMR
・ Device: Nuclear magnetic resonance apparatus (JNM-AL400) manufactured by JEOL Ltd.
Solvent: Deuterated dimethyl sulfoxide Observation frequency: OBFRQ 100.40 MHz, OBSET 125.00 KHz, OBFIN 10500.00 Hz
-Accumulation count: 512 times.

The area of the epoxy ring-derived peak was determined from the obtained ¹ H-NMR spectrum. Moreover, the area of the peak derived from a carbodiimide group was calculated | required from the obtained ¹³ C-NMR spectrum. The peak area was calculated by integrating the area surrounded by the baseline and the peak using the analysis software attached to the NMR apparatus. The peak area of a dry blend of three or more hydroxyl group-containing compounds in one molecule and an epoxy group and / or carbodiimide group-containing compound (b) is d, the peak area of the compound (b) is e, and the reaction rate is It was calculated by the following formula (4).
Reaction rate (%) = {1- (e / d)} × 100 (4)
As an example, a ¹ H-NMR spectrum of a dry blend of “pentaerythritol and bisphenol A type epoxy resin“ jER ”(registered trademark) 1004 manufactured by Mitsubishi Chemical Corporation at a mass ratio of 3: 1” shown in 1. Further, the ¹ H-NMR spectrum of the obtained in reference example 5 (B'-4) compound, from ¹ H-NMR spectrum shown in. Figure 1 shown in FIG. 2, 2.60Ppm and 2. The total of the peak areas derived from the epoxy ring appearing in the vicinity of 80 ppm was obtained, similarly, the sum of the peak areas shown in Fig. 2 was obtained, and the reaction rate was calculated by the reaction rate calculation formula (4). Normalization was performed using the peak area of the benzene ring of the epoxy resin that does not contribute to the reaction.

[Degree of branching]
The compound (B) and the compound (B ′) were subjected to ¹³ C-NMR analysis under the following conditions, and the degree of branching (DB) was calculated from the following formula (5).
Branch degree = (D + T) / (D + T + L) (5)
(In the above formula (5), D represents the number of dendritic units, L represents the number of linear units, and T represents the number of terminal units.)
Said D, T, and L were computed from the peak area measured by < ¹³ > C-NMR. D is derived from a tertiary or quaternary carbon atom, T is derived from a primary carbon atom that is a methyl group, L is a primary or secondary carbon atom, Derived from except T. The peak area was calculated by integrating the area surrounded by the baseline and the peak using the analysis software attached to the NMR apparatus. The measurement conditions are as follows.

(1) ¹³ C-NMR
・ Device: Nuclear magnetic resonance apparatus (JNM-AL400) manufactured by JEOL Ltd.
・ Solvent: Deuterated dimethyl sulfoxide ・ Measurement sample amount / solvent amount: 0.035 g / 0.70 ml
・ Observation frequency: OBFRQ 100.40MHz, OBSET125.00KHz, OBFIN10500.00Hz
-Accumulation count: 512 times.

[Number of hydroxyl groups in one molecule of compound (B) and compound (B ′)]
The number of hydroxyl groups was calculated from the following formula (2) by calculating the number average molecular weight and the hydroxyl value of the compound (B) and the compound (B ′).
Number of hydroxyl groups = (number average molecular weight × hydroxyl value) / 56110 (2)
[Sum of the number of epoxy groups and carbodiimide groups in one molecule of compound (B ′)]
The number of epoxy groups or carbodiimide groups was calculated by dividing the number average molecular weight of the compound (B ′) by the epoxy equivalent or carbodiimide equivalent.

The number average molecular weight and the hydroxyl value of the compound (B) and the compound (B ′) were measured by the method described above. Epoxy equivalent was obtained by dissolving 400 mg of compound (B ′) in 30 ml of hexafluoroisopropanol, then adding 20 ml of acetic acid and tetraethylammonium bromide / acetic acid solution (= 50 g / 200 ml), and 0.1N perchloric acid as a titrant. The crystal violet was used as an indicator, and the titration amount when the color of the solution changed from purple to blue-green was calculated by the following formula (3).
Epoxy equivalent [g / eq] = W / ((FG) × 0.1 × f × 0.001) (3)
(In the above formula, F represents the amount of 0.1N perchloric acid [ml] used for titration, G represents the amount of 0.1N perchloric acid [ml] used for blank titration, f Represents the factor of 0.1N perchloric acid, and W represents the mass [g] of the sample.)
The carbodiimide equivalent was calculated by the following method. 100 parts by mass of the compound (B ′) and 30 parts by mass of potassium ferrocyanide (manufactured by Tokyo Chemical Industry Co., Ltd.) as an internal standard substance were dry blended and subjected to hot pressing at a temperature of about 200 ° C. for 1 minute to produce a sheet. . Thereafter, the infrared absorption spectrum of the sheet was measured by a transmission method using an infrared spectrophotometer (manufactured by Shimadzu Corporation, IR Prestige-21 / AIM8800). The measurement conditions were a resolution of 4 cm ⁻¹ and an integration count of 32 times. In the infrared absorption spectrum in the transmission method, since the absorbance is inversely proportional to the sheet thickness, it is necessary to normalize the peak intensity of the carbodiimide group using the internal standard peak. A value obtained by dividing the absorbance of the carbodiimide group-derived peak appearing in the vicinity of 2140 cm ^{−1 by} the absorbance of the CN group absorption peak of potassium ferrocyanide appearing in the vicinity of 2100 cm ⁻¹ was calculated. In order to calculate the carbodiimide equivalent from this value, IR measurement is performed using a sample whose carbodiimide equivalent is known in advance, and a calibration curve is created using the ratio of the absorbance of the peak derived from the carbodiimide group and the absorbance of the internal standard peak. The absorbance ratio of (B ′) was substituted into the calibration curve, and the carbodiimide equivalent was calculated. Samples having a known carbodiimide equivalent include aliphatic polycarbodiimide (manufactured by Nisshinbo Co., Ltd., “Carbodilite” (registered trademark) LA-1, carbodiimide equivalent 247 g / mol), aromatic polycarbodiimide (manufactured by Rhein Chemie, “STABAXOL” (registered trademark) P) And a carbodiimide equivalent of 360 g / mol).

[Bending strength of laser-transmitting molded product]
The pellets obtained in each Example and Comparative Example were dried under reduced pressure at 80 ° C. for 12 hours, and using an injection molding machine (SG75H-MIV manufactured by Sumitomo Heavy Industries, Ltd.), cylinder temperature: (A) of polyamide resin A laser-transmitting rod-shaped test piece having a thickness of 1/4 inch was manufactured by injection molding under the conditions of melting point + 15 ° C. and mold temperature: 80 ° C. The test piece was subjected to a bending test at a crosshead speed of 3 mm / min using a bending tester Tensilon RTA-1T (Orientec Co., Ltd.) according to ASTM D790. The measurement was performed three times, and the average value was calculated as the bending strength.

[Dimensional stability of laser light-transmitting molded products (low warpage)]
The pellets obtained in Examples and Comparative Examples were dried under reduced pressure for 12 hours at a temperature of 80 ° C., and cylinder temperature: (A) polyamide using an injection molding machine (Sumitomo Heavy Industries, Ltd. SG75H-MIV). By injection molding under the conditions of resin melting point + 15 ° C. and mold temperature: 80 ° C., a 70 mm × 70 mm × 1 mm thick laser light-transmitting square plate is formed, and a gear oven in the atmosphere at a temperature of 130 ° C. The warpage when heat-treated for 1 hour was evaluated.

  In the evaluation, any one of the four sides of the square plate was suppressed, and the warp amount was less than 0.8 mm, ◯, less than 3 mm, and 3 mm or more as x.

[Light transmittance]
The pellets obtained in Examples and Comparative Examples were dried under reduced pressure for 12 hours at a temperature of 80 ° C., and cylinder temperature: (A) polyamide using an injection molding machine (Sumitomo Heavy Industries, Ltd. SG75H-MIV). A laser light transmitting test piece and a laser light absorbing test piece having a length of 128 mm, a width of 13 mm, and a thickness of 3 mm were formed by injection molding under the conditions of the melting point of the resin + 15 ° C. and the mold temperature: 80 ° C. The light transmittance is measured using an ultraviolet / visible spectrophotometer (UV-3100PC manufactured by Shimadzu Corporation), and the ratio of transmitted light intensity to incident light intensity in the near infrared region 940 nm is expressed as a percentage (%). did.

[Laser weldability]
The pellets obtained in Examples and Comparative Examples were dried under reduced pressure for 12 hours at a temperature of 80 ° C., and cylinder temperature: (A) polyamide using an injection molding machine (Sumitomo Heavy Industries, Ltd. SG75H-MIV). By injection molding under the conditions of the melting point of the resin + 15 ° C. and the mold temperature: 80 ° C., a laser light transmitting test piece and a laser light absorbing test piece having a thickness of 80 mm × 80 mm × 3 mm were formed. Further, the test piece was processed to a width of 24 mm × length of 70 mm × 3 mm, and each molded product was overlapped in the length direction so that the overlap length was 30 mm, and the laser welding distance was set to 20 mm. The tensile strength was measured.

  The welding conditions and the welding strength measurement conditions are as follows.

  Leister's MODULAS C was used as a laser welder, and the laser welding conditions were an output of 35 W and a laser scanning speed of 10 mm / sec. The focal length was 38 mm and the focal diameter was fixed at 0.6 mm. In addition, for the measurement of welding strength, a tensile tester Tensilon UTA2.5T (made by Orientec Co., Ltd.) is used, and both ends of the welded test piece are fixed, and a tensile test is performed so that tensile shear stress is generated at the welding site. went. The tensile speed is 1 mm / min and the span is 40 mm. The welding strength was the stress when the welded site was broken, and the measurement was performed three times. The average value was calculated as the welding strength.

[Heat aging resistance of laser light-transmitting molded products]
The pellets obtained in Examples and Comparative Examples were dried under reduced pressure at a temperature of 80 ° C. for 12 hours, and cylinder temperature: polyamide resin (A) using an injection molding machine (Sumitomo Heavy Industries, Ltd. SG75H-MIV). A laser transmissive ASTM No. 1 dumbbell test piece having a thickness of 3.2 mm was produced by injection molding under the conditions of a melting point of + 15 ° C. and a mold temperature of 80 ° C. This test piece was subjected to a tensile test at a crosshead speed of 10 mm / min by a tensile tester Tensilon UTA2.5T (manufactured by Orientec Co., Ltd.) according to ASTM D638. The measurement was performed three times, and the average value was calculated as the tensile strength before the heat aging resistance test treatment. Next, ASTM No. 1 dumbbell test piece was heat-treated in a gear oven at 200 ° C. in the atmosphere for 3000 hours (heat aging resistance test process). The average value was calculated as the tensile strength after the heat aging resistance test treatment. The ratio of the tensile strength after the treatment to the tensile strength before the heat aging resistance test treatment was calculated as the tensile strength retention rate. The greater the tensile strength retention, the better the heat aging resistance.

Reference Example 1 (E-1: Nylon 66 masterbatch containing Cu / K (mass ratio) = 0.23)
To 100 parts by mass of nylon 66 (“Amilan” (registered trademark) CM3001-N manufactured by Toray Industries, Inc.), 2.0 parts by mass of copper iodide and 21.7 parts by mass of potassium iodide 40% aqueous solution were premixed. Thereafter, using a TEX30 type twin screw extruder (L / D: 45.5) manufactured by Nippon Steel, Ltd., the mixture was melt-kneaded under conditions of a cylinder temperature of 275 ° C. and a screw rotation speed of 150 rpm, and pelletized by a strand cutter. . Then, it vacuum-dried at the temperature of 80 degreeC for 8 hours, and produced the masterbatch pellet whose copper content is 0.60 mass%.

Reference example 2 (B′-1)
A phenol novolac epoxy resin (“EPPN” (registered trademark) 201 manufactured by Nippon Kayaku Co., Ltd.) is used for 100 parts by mass of dipentaerythritol (manufactured by Guangei Chemical Industry Co., Ltd., molecular weight / number of functional groups 42 per molecule). ) After preliminarily mixing 10 parts by mass, the mixture was melt-kneaded for 3.5 minutes under the conditions of a cylinder temperature of 200 ° C. and a screw rotation speed of 100 rpm using a Ikegai PCM30 type twin screw extruder, and pelletized by a hot cutter. The obtained pellets were supplied again to the extruder, and the remelting and kneading step was performed once to obtain pellets of the compound represented by the general formula (1). The reaction rate of the obtained compound was 53%, the degree of branching was 0.29, and the hydroxyl value was 1280 mgKOH / g. There are three or more hydroxyl groups in one molecule, and the number of hydroxyl groups in one molecule is larger than the number of epoxy groups in one molecule, and the sum of the number of OH and OR in the general formula (1) is three or more. Met.

Reference example 3 (B'-2)
In the same manner as in Reference Example 5 except that the screw rotation speed of the twin screw extruder was changed to 300 rpm and the melt kneading time was changed to 0.9 minutes, the compound represented by the general formula (1) was changed. Pellets were obtained. The reaction rate of the obtained compound was 2%, the degree of branching was 0.15, and the hydroxyl value was 1350 mgKOH / g. There are three or more hydroxyl groups in one molecule, and the number of hydroxyl groups in one molecule is larger than the number of epoxy groups in one molecule, and the sum of the number of OH and OR in the general formula (1) is three or more. Met.

Reference example 4 (B'-3)
10 parts by weight of phenol novolac type epoxy resin (“EPPN” (registered trademark) 201 manufactured by Nippon Kayaku Co., Ltd.), 100 parts by weight of dipentaerythritol (manufactured by Guangei Chemical Industry Co., Ltd.), 1,8-diazabicyclo After preliminarily mixing 0.3 part by mass of (5, 4, 0) -undecene-7 (manufactured by Tokyo Chemical Industry Co., Ltd.), cylinder temperature 200 ° C. using a PCM30 type twin screw extruder manufactured by Ikegai Co., Ltd. The mixture was melt-kneaded for 3.5 minutes under the condition of a screw speed of 100 rpm and pelletized with a hot cutter. The obtained pellets were supplied to an extruder, and the remelting and kneading step was further performed 6 times to obtain pellets of the compound represented by the general formula (1). The reaction rate of the obtained compound was 96%, the degree of branching was 0.39, and the hydroxyl value was 1170 mgKOH / g. There are three or more hydroxyl groups in one molecule, and the number of hydroxyl groups in one molecule is larger than the number of epoxy groups in one molecule, and the sum of the number of OH and OR in the general formula (1) is three or more. Met.

Reference example 5 (B'-4)
Bisphenol A type epoxy resin ("jER" (registered trademark) 1004 manufactured by Mitsubishi Chemical Corporation) per 100 parts by mass of dipentaerythritol (manufactured by Guangei Chemical Industry Co., Ltd.), two epoxy groups in one molecule , Molecular weight 1650, molecular weight / number of functional groups in one molecule 825) After pre-mixing 33.3 parts by mass, using a PCM30 type twin screw extruder manufactured by Ikegai Co., Ltd., cylinder temperature 200 ° C., screw rotation speed 100 rpm The mixture was melt-kneaded for 3.5 minutes under the conditions, and pelletized with a hot cutter. The obtained pellets were supplied again to the extruder, and the remelting and kneading step was performed once to obtain pellets of the compound represented by the general formula (1). The reaction rate of the obtained compound was 56%, the degree of branching was 0.34, and the hydroxyl value was 1200 mgKOH / g. There are three or more hydroxyl groups in one molecule, and the number of hydroxyl groups in one molecule is larger than the number of epoxy groups in one molecule, and the sum of the number of OH and OR in the general formula (1) is three or more. Met.

Reference Example 6 (B′-5)
Aliphatic polycarbodiimide (Nisshinbo Chemical Co., Ltd. “Carbodilite” (registered trademark) LA-1) per 100 parts by mass of dipentaerythritol (Guangei Chemical Industry Co., Ltd.), average of carbodiimide groups in one molecule After 24 parts, molecular weight 6000, molecular weight / functional group number in one molecule 250) 10 parts by mass, using a PCM30 type twin screw extruder manufactured by Ikegai Co., Ltd., cylinder temperature 200 ° C., screw rotation speed 100 rpm The mixture was melt-kneaded for 3.0 minutes under the above conditions and pelletized with a hot cutter. The obtained pellets were supplied again to the extruder, and the remelting and kneading step was performed once to obtain pellets of the compound represented by the general formula (1). The reaction rate of the obtained compound was 68%, the degree of branching was 0.37, and the hydroxyl value was 1110 mgKOH / g. One molecule has three or more hydroxyl groups, the number of hydroxyl groups in one molecule is larger than the number of carbodiimide groups in one molecule, and the sum of the number of OH and OR in the general formula (1) is 3 or more Met.

Reference example 7 (B'-6)
After pre-mixing 500 parts by mass of a phenol novolac epoxy resin (“EPPN” (registered trademark) 201) manufactured by Nippon Kayaku Co., Ltd. with respect to 100 parts by mass of dipentaerythritol (manufactured by Guangei Chemical Industry Co., Ltd.) Using a PCM30 type twin screw extruder manufactured by Ikegai Co., Ltd., melt-kneading for 3.5 minutes under conditions of a cylinder temperature of 200 ° C. and a screw rotation speed of 100 rpm, pelletized by a hot cutter, and represented by the general formula (1) Compound pellets were obtained. The reaction rate of the obtained compound was 33%, the degree of branching was 0.23, and the hydroxyl value was 540 mgKOH / g. There are three or more hydroxyl groups in one molecule, the number of hydroxyl groups in one molecule is less than the number of epoxy groups in one molecule, and the sum of the number of OH and OR in the general formula (1) is three or more Met.

Reference example 8 (B'-7)
After 100 parts by weight of diglycerin (manufactured by Sakamoto Pharmaceutical Co., Ltd.) and 10 parts by weight of novolak phenol type modified epoxy resin (“EPPN” (registered trademark) 201 manufactured by Nippon Kayaku Co., Ltd.), Using a PCM30 type twin screw extruder manufactured by Ikegai Co., Ltd., the mixture was melt-kneaded for 3.5 minutes under conditions of a cylinder temperature of 100 ° C. and a screw rotation speed of 100 rpm, and pelletized by a hot cutter. The obtained pellets are again supplied to an extruder, melt-kneaded and pelletized under the same conditions as described above, and pellets of a compound having no quaternary carbon and not having the structure represented by the general formula (1) are obtained. Obtained. The reaction rate of the obtained compound was 38%, the degree of branching was 0.02, and the hydroxyl value was 1240 mgKOH / g. One molecule has three or more hydroxyl groups, and the number of hydroxyl groups in one molecule is larger than the number of epoxy groups in one molecule, and has three or more hydroxyl groups in one molecule.

Reference example 9 (F-1)
After premixing 26.7 parts by mass of the compound (B′-1) with 100 parts by mass of nylon 6 (“Amilan” (registered trademark) CM1010 manufactured by Toray Industries, Inc.), TEX30 manufactured by Nippon Steel Works Using a mold twin screw extruder (L / D: 45.5), the mixture was melt-kneaded under conditions of a cylinder temperature of 245 ° C. and a screw rotation speed of 150 rpm, and pelletized by a strand cutter. Then, it vacuum-dried at the temperature of 80 degreeC for 8 hours, and produced the high concentration pre-mixture pellet.

  In addition, the polyamide resin (A) used in Examples and Comparative Examples, a compound (B) containing three or more hydroxyl groups in one molecule, an epoxy group and / or carbodiimide group-containing compound (b), and a filler (D) The laser light absorbing additive (G) and the polybutylene terephthalate resin (H) are as follows.

  (A-1): Nylon 6 resin having a melting point of 225 ° C. (“Amilan” (registered trademark) CM1010 manufactured by Toray Industries, Inc.).

  (A-2): Nylon 66 resin (“Amilan” (registered trademark) CM3001-N manufactured by Toray Industries, Inc.) having a melting point of 225 ° C.

  (B-1): Dipentaerythritol (manufactured by Guangei Chemical Industry Co., Ltd.), molecular weight 254, hydroxyl value 1325 mgKOH / g. It has 6 hydroxyl groups in one molecule.

  (B-2): 2,2,4-trimethyl-1,3-pentanediol (manufactured by Tokyo Chemical Industry Co., Ltd.), molecular weight 146, hydroxyl value 765 mgKOH / g. It has two hydroxyl groups in one molecule.

  (B-1): Phenol novolak type epoxy resin (“EPPN” (registered trademark) 201 manufactured by Nippon Kayaku Co., Ltd.), an average number of epoxy groups in one molecule of 7, molecular weight of 1330, molecular weight of 1 molecule 190 functional groups.

  (C-1): Sodium hypophosphite monohydrate (Wako Pure Chemical Industries, Ltd.), molecular weight 105.99.

  (D-1): Circular cross-section glass fiber (T-717H manufactured by Nippon Electric Glass Co., Ltd.), cross-sectional diameter 10.5 μm, surface treatment agent: silane coupling agent, bundling agent: epoxy system, fiber length 3 mm.

  (G-1): Carbon black (manufactured by Mitsubishi Chemical Corporation, MA600B).

  (H-1): Polybutylene terephthalate resin having a melting point of 224 ° C. (“Toraycon” 1401X06 manufactured by Toray Industries, Inc.).

(Examples 1-14, 16 and 22, Comparative Examples 1-8)
Polyamide resin (A) shown in Tables 1-4, epoxy group and / or carbodiimide group-containing compound (b), copper compound (E) TEX30 type twin screw extruder (L / D) manufactured by Nippon Steel, Ltd., in which the cylinder set temperature was set to the melting point of the polyamide resin + 15 ° C. and the screw rotation speed was set to 200 rpm. = 45) from the main feeder to the twin screw extruder and melt kneaded. This main feeder was connected to a position 0 when viewed from the upstream side when the total length of the screw was 1.0, that is, a position of an end portion on the upstream side of the screw segment. Subsequently, the compound (B), the compound (B ′), the phosphorus-containing compound (C), and the filler (D) shown in the table were supplied from the side feeder to the twin-screw extruder and melt-kneaded. This side feeder was connected to a position of 0.65 when viewed from the upstream side when the total length of the screw was 1.0, that is, a position downstream of 1/2 of the screw length. The screw configuration of the twin screw extruder is such that the total length of the kneading zone on the upstream side of the supply position of the compound (B) is Ln1, and the total length of the kneading zone on the downstream side of the supply position of the compound (B) etc. When the length is Ln2, Ln1 / L is 0.14 and Ln2 / L is 0.07. The gut discharged from the die was immediately cooled in a water bath and pelletized with a strand cutter. The obtained pellets were used for laser light transmitting molded products and laser light absorbing molded products. The evaluation results of Examples and Comparative Examples are shown in Tables 1, 2, and 4.

(Example 15)
Polyamide resin (A), high-concentration premix (F), and phosphorus-containing compound (C) shown in Table 2 (in the case of forming a laser-absorbing molded product, and further a laser-absorbing additive (G)) After pre-mixing, two axes from the main feeder of TEX30 type twin screw extruder (L / D = 45) manufactured by Nippon Steel, Ltd., where the cylinder set temperature was set to the melting point of polyamide resin + 15 ° C. and the screw rotation speed was set to 200 rpm. It was supplied to an extruder and melt kneaded. This main feeder was connected to a position 0 when viewed from the upstream side when the total length of the screw was 1.0, that is, a position of an end portion on the upstream side of the screw segment. Subsequently, the filler (D) shown in the table was supplied from the side feeder to the twin screw extruder and melt kneaded. This side feeder was connected to a position 0.65 when viewed from the upstream side when the total length of the screw was 1.0, that is, a position downstream from 1/2 of the screw length. The cylinder temperature, screw rotation speed, and screw configuration are the same as in Example 7. Thus, the composition ratio in Example 15 is the same as in Example 7. The obtained pellets were used for laser light transmitting molded products and laser light absorbing molded products. The evaluation results of the examples are shown in Table 2.

(Examples 17 to 21)
Polyamide resin (A) or polybutylene terephthalate resin (H) shown in Table 3 and (when laser-absorbing molded products are molded, laser beam-absorbing additive (G)), and cylinder set temperature are set to polyamide. The melting point of the resin was + 15 ° C., and the screw rotation speed was set to 200 rpm. The TEX30 type twin screw extruder (L / D = 45) manufactured by Nippon Steel Works, Ltd. was supplied to the twin screw extruder and melt kneaded. This main feeder was connected to a position 0 when viewed from the upstream side when the total length of the screw was 1.0, that is, a position of an end portion on the upstream side of the screw segment. Subsequently, the compound (B ′), the phosphorus-containing compound (C) and the filler (D) shown in Table 3 were supplied from the side feeder to the twin-screw extruder and melt-kneaded. This side feeder was connected to a position 0.65 when viewed from the upstream side when the total length of the screw was 1.0, that is, a position downstream from 1/2 of the screw length. The screw configuration of the twin screw extruder is such that the total length of the kneading zone on the upstream side of the supply position of the compound (B) is Ln1, and the total length of the kneading zone on the downstream side of the supply position of the compound (B) etc. When the length is Ln2, Ln1 / L is 0.14 and Ln2 / L is 0.07. The gut discharged from the die was immediately cooled by a water bath and pelletized by a strand cutter. The obtained pellets were used for laser light transmitting molded products and laser light absorbing molded products as shown in Table 3. Table 3 shows the evaluation results of Examples and Comparative Examples.

  Examples 1-22 are compound (B) as a polyamide resin composition for laser welding of the use for laser-light-transmitting molded articles and / or laser-light-absorbing molded articles compared with Comparative Examples 1-8. Alternatively, by containing a specific amount of the compound (B ′) and containing a phosphorus atom derived from the phosphorus-containing compound (C) at a specific concentration, the polyamide resin (A) and the compound (B) or the compound (B ′) As a result, a molded article excellent in weldability, mechanical strength and dimensional stability could be obtained.

  Moreover, since Examples 1-5 contain 0.1-20 mass parts of compounds (B) and contain phosphorus atoms derived from phosphorus-containing compounds (C) at specific concentrations, they are compared with Comparative Examples 1-6. Thus, the compatibility between the polyamide resin (A) and the compound (B) was further improved, and as a result, a molded product having excellent weldability, mechanical strength and dimensional stability could be obtained.

  Example 6 contains the compound (B) and uses the epoxy group and / or carbodiimide group-containing compound (b) together to produce the compound (B ′) at the time of melt kneading with the polyamide resin (A). Therefore, compared with Example 2, the compatibility between the polyamide resin (A) and the (B ′) compound was improved, and a molded product having excellent weldability, mechanical strength, and heat aging resistance could be obtained.

  In Examples 7 to 13, since the (B ′) compound was generated in advance, compared with Example 6, the compatibility between the polyamide resin (A) and the compound (B ′) was further improved, and the weldability, machine A molded article excellent in strength and heat aging resistance could be obtained.

  In Examples 7, 10, and 11, compared with Examples 8 and 9, since the reaction rate of the hydroxyl group and the epoxy group and / or carbodiimide group is in a more preferable range, the polyamide resin (A) and the compound (B The compatibility with ') was further improved, and a molded product excellent in weldability, mechanical strength and heat aging resistance could be obtained.

  In Examples 7 to 11, as compared with Examples 12 and 13, the compound (B ′) had a larger number of hydroxyl groups in one molecule than the sum of the number of epoxy groups and / or carbodiimide groups. Since it has the structure represented by the formula (1), the compatibility between the polyamide resin (A) and the compound (B ′) is further improved, and a molded product having excellent weldability, mechanical strength, and heat aging resistance can be obtained. did it.

  Since Example 14 further contains a copper compound as compared with Example 7, the compatibility between the polyamide resin (A) and the compound (B ′) is further improved, and weldability, mechanical strength, and heat aging resistance are improved. It was possible to obtain a molded product excellent in.

  In Example 15, compared with Example 7, a high-concentration preliminary mixture was prepared in advance, so that the compatibility between the polyamide resin (A) and the compound (B ′) was further improved, and the weldability, mechanical strength, and heat resistance were improved. A molded article excellent in aging property could be obtained.

  Example 7 contains a specific amount of compound (B ′) as a polyamide resin composition for laser light-absorbing molded articles and phosphorus derived from a phosphorus-containing compound (C) as compared with Examples 17 and 18. By containing atoms at a specific concentration, it was possible to obtain a molded article having better weldability.

  Example 7 contains a specific amount of compound (B ′) as a polyamide resin composition for a laser light-transmitting molded article and phosphorus derived from a phosphorus-containing compound (C) as compared with Examples 19 to 21. By containing atoms at a specific concentration, it was possible to obtain a molded article having better weldability.

1: Solvent peak

Claims (8)

  Spectrophotometric analysis method containing 0.1 to 20 parts by mass of a compound (B) containing three or more hydroxyl groups in one molecule and a phosphorus-containing compound (C) per 100 parts by mass of the polyamide resin (A) The phosphorous atom content obtained by the above is 400 to 3500 ppm with respect to the polyamide resin content.   2. The polyamide resin composition for laser welding according to claim 1, wherein the phosphorus-containing compound (C) is at least one selected from the group consisting of phosphorous acid, hypophosphorous acid and metal salts thereof. .   The compound (B) has a hydroxyl group and an epoxy group and / or a carbodiimide group, and the number of hydroxyl groups in one molecule is larger than the sum of the number of epoxy groups and carbodiimide groups in one molecule. Item 3. A polyamide resin composition for laser welding according to item 1 or 2.   The compound (B) has a hydroxyl group and an epoxy group and / or carbodiimide group, and the compound (B) is a reaction product of the hydroxyl group-containing compound and the epoxy group and / or carbodiimide group-containing compound (b). The polyamide resin composition for laser welding according to any one of claims 1 to 3, wherein a reaction rate between a hydroxyl group and an epoxy group or a carbodiimide group is 3 to 95%. The compound (B) is a compound having a structure represented by the following general formula (1) and / or a condensate thereof, and the polyamide resin composition for laser welding according to any one of claims 1 to 4, object.
(In the general formula (1), X ^{1 to} X ⁶ may be the same or different and each represents OH, CH ₃ or OR. However, the sum of the number of OH and OR is 3 or more. Represents an organic group having an epoxy group or a carbodiimide group, and n represents a range of 0 to 20.)   6. The laser welding polyamide resin composition according to claim 1, further comprising a laser light absorbing additive.   The electrical / electronic component which consists of a polyamide resin composition for laser welding in any one of Claims 1-6.   The laser welding polyamide resin composition according to any one of claims 1 to 7 is used as a laser light transmitting molded product and / or a laser light absorbing molded product, and the laser light transmitting molded product and the laser light absorbing property. A laser welding method characterized by contacting a molded product and irradiating a laser beam from the laser light transmissive molded product side to laser weld them.