JP5034217B2 - Laser welding resin composition and composite molded body using the same - Google Patents

Description

  The present invention relates to a resin composition for laser welding having excellent balance of heat resistance, heat resistance, molded article surface appearance, dimensional stability, and laser weldability, and a composite molded article using the same, and further to other articles. The present invention relates to a resin composition for laser welding suitable for a composite molded body obtained by laser welding and a composite molded body using the same.

  Polybutylene terephthalate resin uses its excellent injection moldability, mechanical properties, heat resistance, electrical properties, chemical resistance, etc. to make a wide range of injection molded products in the fields of mechanical parts, electrical / communication parts, automotive parts, etc. Has been used. However, although the molding efficiency of the injection molded product is good, the shape is limited in terms of its flow characteristics and mold structure, and it is difficult to mold a complicated one.

  Conventionally, in joining parts due to the complexity of product shape, joining with an adhesive, mechanical joining with a bolt or the like has been performed. However, adhesives have problems of adhesive strength, and mechanical joining with bolts and the like has problems of cost, labor for fastening, and weight increase. On the other hand, external heat welding such as laser welding and hot plate welding, friction heat welding such as vibration welding and ultrasonic welding can be performed in a short time, and no adhesive or metal parts are used. Since problems such as cost, weight increase and environmental pollution do not occur, assembly by these methods is increasing.

  Laser welding, which is one of external heat welding, is a method of irradiating a laser beam to the superimposed resin moldings, transmitting the irradiated one, absorbing it, melting and fusing it, and enabling three-dimensional bonding It is a method that is spreading in a wide range of fields, taking advantage of non-contact processing and the absence of burrs.

  In this construction method, in the resin material applied to the laser beam transmission side molded body, the characteristic of transmitting the laser beam is essential, and when the energy of the irradiated laser beam is 100%, it is transmitted to the back side of the laser beam transmission side molded body. As a result of the examination by the present inventors, it has been found that the energy to be output needs to be 10% or more. When a molded article having a laser beam transmittance of less than 10% is used as the molded article on the laser beam transmission side, there is a sufficient possibility that defects such as melting and smoke generation may occur on the laser beam incident surface.

  The polybutylene terephthalate resin used in many applications has a very low laser beam transmittance compared to thermoplastic resins such as nylon resin. The polybutylene terephthalate resin is used as a molded product on the laser beam transmission side. When applying the welding method, the thickness limit is very strict due to its low laser beam transmittance, and it is necessary to deal with the thinning to improve the laser beam transmittance, and the degree of freedom in product design is small.

  In Patent Document 1, it is described that the welding condition width is widened by controlling the melting point by using a polybutylene terephthalate copolymer in the laser welding method. A great improvement cannot be expected. Therefore, an improvement in the degree of freedom in the thickness design of the molded article cannot be expected, and the moldability of the polybutylene terephthalate resin is impaired.

In addition, in polybutylene terephthalate-based resins that are used in various applications, there are cases where impact resistance is improved by adding an elastomer disclosed in Patent Document 2 and cold resistance is improved. There is a problem that the retention stability is insufficient and the fluidity is lowered during continuous molding.
JP 2001-26656 A (paragraphs [0008] to [0024]) Japanese Patent Laying-Open No. 2003-292752 (paragraphs [0025] to [0027])

  The present invention solves the above-mentioned conventional problems, and even in polybutylene terephthalate resin, it does not reduce the degree of freedom in product design, and is excellent in residence heat stability at the time of molding and impairs laser light transmittance. It aims at providing the resin composition for laser welding which can be applied as a laser beam transmission side molded object, without any.

  In view of the above situation, the present inventors have made extensive studies, and as a result, polybutylene terephthalate resin, at least one resin selected from polycarbonate resin, acrylonitrile / styrene copolymer, styrene and butadiene, By adding a styrene-based elastomer that is a copolymer of the above and a specific phosphate-based stabilizer, there is no decrease in laser light transmittance, excellent cold resistance, and good thermal stability during molding. The present inventors have found that a resin composition for laser welding can be obtained and have reached the present invention.

In order to solve the above problems, the present invention has the following configuration. That is,
(1) (A) polybutylene terephthalate or polybutylene terephthalate resin comprising polybutylene terephthalate and a polybutylene terephthalate copolymer 50 to 99% by weight,
(B) A resin composition comprising 1 to 50% by weight of at least one resin selected from polycarbonate resins and acrylonitrile / styrene copolymers,
Furthermore, (C) 1-25 parts by weight of styrene-based elastomer, which is a copolymer of styrene and butadiene, with respect to 100 parts by weight of the total amount of (A) and (B),
(D) A phosphate stabilizer having the following formulas (1) and (2) and a blending ratio of (1) :( 2) = 35: 65 to 45:55 is the sum of (A) and (B). Laser welding resin composition containing 0.01 to 1.0 part by weight with respect to 100 parts by weight,

_(Wherein, R 1, _{R 2} and _{R 3} represents an alkyl group which may have an unsaturated bond having 8 to 30 carbon atoms.)
(2) Further, (E) at least one selected from inorganic fillers and organic fillers is added to 1 to 200 parts by weight with respect to 100 parts by weight of the total amount of (A) and (B). The laser welding resin composition according to the above (1),
(3) A molded product comprising the laser welding resin composition according to (1) or (2) above,
(4) The molded product according to (4), wherein the laser beam transmittance in the near infrared 800 to 1100 nm wavelength region measured at a sample thickness of 3 mm is 10% or more (5) The above (3) or (4) A composite molded product obtained by laser welding the molded product described in 1.
Is to provide.

  In the present invention, a polybutylene terephthalate resin is blended with at least one resin selected from a polycarbonate resin and an acrylonitrile / styrene copolymer, a styrene elastomer which is a copolymer of styrene and butadiene, and By adding a phosphate-based stabilizer, it is possible to obtain a laser-welding resin composition that does not have a decrease in laser beam transmittance, is excellent in heat resistance, and has good heat discoloration. It can be used suitably.

  Embodiments of the present invention will be described below.

  In the present invention, the (A) polybutylene terephthalate resin (hereinafter also referred to as the component (A)) may be the polybutylene terephthalate alone, or a combined use of polybutylene terephthalate and a polybutylene terephthalate copolymer. It may be.

  The polybutylene terephthalate used in the present invention is a polymer obtained by polycondensation reaction of terephthalic acid (or its ester-forming derivative such as dimethyl terephthalate) and 1,4-butanediol (or its ester-forming derivative). It is.

  The polybutylene terephthalate copolymer that can be used in combination with the polybutylene terephthalate includes terephthalic acid (or an ester-forming derivative such as dimethyl terephthalate) and 1,4-butanediol (or an ester-forming derivative thereof). ) And other dicarboxylic acids copolymerizable therewith (or ester-forming derivatives thereof) or other diols (or ester-forming derivatives thereof), and other dicarboxylic acids as the third component. A copolymer obtained by copolymerizing an acid (or an ester-forming derivative thereof) is preferable.

  The copolymerization ratio of the other dicarboxylic acid (or its ester-forming derivative) is preferably in the range of 3 to 30 mol% in the total dicarboxylic acid component from the viewpoint of moldability, and in the range of 3 to 20 mol%. More preferably.

  In addition, the copolymerization ratio of other diols (or ester-forming derivatives thereof) is preferably in the range of 3 to 30 mol% in the total diol component from the viewpoint of moldability, and in the range of 3 to 20 mol%. More preferably.

  Examples of the other dicarboxylic acids include isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, anthracene dicarboxylic acid, and 4,4′-diphenyl ether dicarboxylic acid. Acids, aromatic dicarboxylic acids such as 5-sodiumsulfoisophthalic acid, aromatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, etc. And alicyclic dicarboxylic acid.

  When only the polybutylene terephthalate copolymer is used as the component (A), the moldability is lowered by the addition of at least one selected from polycarbonate resin and acrylonitrile / styrene copolymer.

  The viscosity of the component (A) is not particularly limited as long as it can be melt-kneaded. However, it is usually preferable that the intrinsic viscosity when an o-chlorophenol solution is measured at 25 ° C. is 0.36 to 1.60. . When component (A) is composed of polybutylene terephthalate and polybutylene terephthalate copolymer, the physical or molten mixture is dissolved in o-chlorophenol after pulverization or in the form of pellets, and o-chloro The result of adjusting the phenol solution and measuring the viscosity only has to be within the viscosity condition.

  In the present invention, at least one resin selected from (B) polycarbonate resin and acrylonitrile / styrene copolymer (hereinafter also referred to as (B) component) is used together with the above-mentioned component (A). In order to obtain a stable composition, it is preferable to use a polycarbonate resin.

  The blending amount of the component (B) relative to the sum of (A) and (B) is 1 to 50% by weight, preferably 5 to 40% by weight, from the viewpoint of improving the laser beam transmittance. When the blending amount of the component (B) is less than 1% by weight, the laser beam permeability is insufficient, and when it exceeds 50% by weight, the moldability and high-temperature rigidity are deteriorated. By using the above resin, the laser transmittance in the near infrared 800-1200 nm wavelength region measured at a sample thickness of 3 mm can be made 10% or more, and good laser transmittance can be obtained.

  In the present invention, impact resistance and cold resistance are imparted by blending (C) styrene elastomer (hereinafter referred to as (C) component) with respect to (A) component and (B) component. Here, the resistance to cold and heat is a resin molded body formed by insert molding of metal or the like, which is greatly different from polybutylene terephthalate resin, etc., and has resistance to cracking in repeated environments at low and high temperatures. To tell. As said (C) component, a styrene-butadiene block copolymer is mentioned preferably, More preferably, the epoxidized material of a styrene-butadiene block copolymer is mentioned.

  The addition amount of the component (C) used in the present invention is 1 with respect to 100 parts by weight of the total amount of the component (A) and the component (B) from the balance of laser beam transmittance, moldability, heat resistance, and heat discoloration resistance. It is the range of -25 weight part, The range of 2-20 weight part is more preferable. If the added amount is less than 1 part by weight, there is almost no effect of impact resistance and cold resistance due to the addition of the component (C), and if it exceeds 25 parts by weight, the moldability, particularly the fluidity is lowered, and the heat discoloration is also lowered. It is not preferable.

  The (D) phosphate-based stabilizer referred to in the present invention is excellent in residence heat stability by using a combination of alkyl phosphoric acid represented by the following formulas (1) and (2) or a metal salt thereof. Is obtained.

_(Wherein, R 1, _{R 2} and _{R 3} represents an alkyl group which may have an unsaturated bond having 8 to 30 carbon atoms.)

In the general formula (1) or (2), examples of the alkyl group having 8 to 30 carbon atoms represented by R ₁ , R ₂ and R ₃ include octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl. , Pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, heicosyl, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, heptacosyl, octacosyl, nonacosyl, triacontyl, and the like, which are straight-chained Or a mixed alkyl thereof. Moreover, these may have an unsaturated bond. Examples of the metal species that can provide these metal salts include sodium, magnesium, calcium, barium, zinc, and aluminum.

  These alkyl phosphoric acids or their metal salts are phosphoric monoesters or diesters of alcohols or their metal salts. Examples of alcohols that can provide them are octanol, isooctanol, 2-ethylhexanol. , Nonyl alcohol, decyl alcohol, undecanol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, 2-dodecanol, 2-tetradecanol, 2-hexadecanol, 2-octadecanol, etc., or These mixed alcohols, palm oil reduced alcohol, beef tallow reduced alcohol, and natural alcohols such as Macquarco alcohol are listed.

  In the present invention, the blending ratio of the formulas (1) and (2) of the component (D) is (1) :( 2) = 35: 65 to 45:55, and the addition amount is between the component (A) and the component (B). It is 0.01-1.0 weight part with respect to 100 weight part of total amounts of a component. If the blending ratio is outside this range, the residence heat stability will not be exhibited, and if the addition amount is less than 0.01 parts by weight, the residence heat stability due to the addition of component (C) will not be exhibited, and 1.0 part by weight Exceeding the range is not preferable because the mechanical properties deteriorate.

  In the present invention, (E) inorganic and organic fillers (hereinafter referred to as “component (E)”) can be further blended. As component (E), glass fibers, carbon fibers, potassium titanate whiskers, zinc oxide whiskers, aluminum borate whiskers, aramid fibers, alumina fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, gypsum fibers, metal fibers, etc. Reinforcing materials, wollastonite, zeolite, sericite, kaolin, mica, clay, pyrofilament, bentonite, asbestos, talc, alumina silicate and other silicates, alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, iron oxide, etc. Metal compounds, carbonates such as calcium carbide, magnesium carbonate and dolomite, sulfates such as calcium sulfate and barium sulfate, glass beads, ceramic beads, boron nitride, silicon carbide and non-fibrous reinforcing materials such as silica and the like. , These are 2 or more types It may be combined. A preferred example is glass fiber. Furthermore, it is more preferable to use these fillers after being pretreated with a coupling agent such as silane, epoxy, or titanate.

  The addition amount of the component (E) used in the present invention is 1 to 200 parts by weight with respect to 100 parts by weight of the total amount of the component (A) and the component (B), from the balance between fluidity and mechanical strength. More preferably, it is 5-120 weight part, Especially 10-85 weight part is preferable.

  The resin composition for laser welding of the present invention includes a release agent, an antioxidant, a stabilizer other than the component (D), a lubricant, a crystal nucleating agent, a terminal blocking agent, and an ultraviolet ray as long as the effects of the present invention are not impaired. Normal additives such as absorbents, colorants, flame retardants and other small amounts of other polymers can be added, but especially by adding a crystal nucleating agent, the crystallization rate (solidification rate) is increased, It is possible to shorten the molding cycle.

  Examples of the crystal nucleating agent include polyether ether ketone resin and talc. Examples of mold release agents include montanic acid waxes, metal soaps such as lithium stearate and aluminum stearate, higher fatty acid amides such as ethylene bisstearyl amide, and ethylenediamine / stearic acid / sebacic acid polycondensates. Of these, montanic acid waxes and ethylene bisstearyl amide are preferred.

  Examples of antioxidants include 2,6-di-t-butyl-4-methylphenol, tetrakis (methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) methane, tris Phenol compounds such as (3,5-di-t-butyl-4-hydroxybenzidine) isocyanurate, sulfur such as dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate Examples thereof include phosphorus compounds such as compounds, trisnonylphenyl phosphite, disaryl pentaerythritol diphosphite, among others, 2,6-di-t-butyl-4-methylphenol, tetrakis (methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate) methane is preferred.

  Examples of stabilizers other than the component (D) include benzotriazole compounds including 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, and benzophenone compounds such as 2,4-dihydroxybenzophenone. Can be mentioned.

  Examples of the end-capping agent include aliphatic and aromatic glycidyl esters or glycidyl ethers.

  These various additives may have a synergistic effect by combining two or more kinds, and may be used in combination.

  For example, the additive exemplified as the antioxidant may act as a stabilizer or an ultraviolet absorber. Some of those exemplified as stabilizers also have an antioxidant action and an ultraviolet absorption action. In other words, the classification is for convenience and does not limit the action.

  What is necessary is just to implement about the manufacturing method of the resin composition for laser welding of this invention by the method generally known, and it does not need to specifically limit. Typical examples include a melt kneading method at a temperature of 200 to 350 ° C. using a known melt mixer such as a single or twin screw extruder, a Banbury mixer, a kneader, or a mixing roll. Each component may be mixed in advance and then melt kneaded. Alternatively, for 100 parts by weight of the total amount of the components (A) to (E), for a small amount of additive component such as 1 part by weight or less, after other components are kneaded and pelletized by the above method, It can also be added before molding. In addition, although it is better that the water | moisture content adhering to each component is less and it is desirable to dry beforehand, not all the components need to be dried.

  As an example of a preferable production method, a twin screw extruder having a cylinder temperature of 230 to 300 ° C. is used, and components other than the component (E) are supplied and kneaded from the upstream side of the extruder, and then the component (E) is side fed. Furthermore, the method of kneading is mentioned.

  The resin composition for laser welding of the present invention is generally formed by a known thermoplastic resin molding method such as injection molding, extrusion molding, blow molding, transfer molding, vacuum molding, etc., among which it is preferably molded by injection molding. .

  The molded article made of the laser welding resin composition of the present invention preferably has a laser beam transmittance of 10% or more in the near infrared 800 to 1100 nm wavelength region when measured at a sample thickness of 3 mm. When the laser beam transmittance in the near infrared 800 to 1100 nm wavelength region measured at a sample thickness of 3 mm of the molded product is 10% or more, a high welding strength can be obtained when the molded product is laser welded. The laser beam transmittance of the molded product under the above conditions is preferably 12% or more. It is because high welding strength can be obtained by setting it as 12% or more.

  In the present invention, an ultraviolet and near-infrared spectrophotometer (UV-3100) manufactured by Shimadzu Corporation is used for laser beam transmittance evaluation, and an integrating sphere is used for the detector. The laser beam transmittance is obtained by measuring the beam transmittance in the near infrared 800 to 1100 nm wavelength region using a sample having a thickness of 3 mm, and expressing the ratio between the transmitted light amount and the incident light amount as a percentage. In the measurement of the laser beam transmittance in the near infrared 800 to 1100 nm wavelength region, the laser beam transmittance is measured every 10 nm, and the maximum value and the minimum value of the laser beam transmittance in the near infrared 800 to 1100 nm wavelength region are obtained. Fig.2 (a) is a top view showing a laser beam transmittance | permeability evaluation test piece, (b) is a side view showing the test piece. The laser beam transmittance evaluation test piece 8 was a rectangular parallelepiped with a square bottom, the bottom side L2 being 80 mm, and the thickness D1 being 3 mm. The laser beam transmittance of 3 mm in thickness is measured by measuring the laser beam transmittance of this test piece.

  The laser welding resin composition of the present invention is used as a material for laser welding by making use of its excellent characteristics, but is suitable for a laser beam transmission side molded article of a laser welding method, and By adding a near-infrared absorber such as carbon black, it can be easily applied to a molded article on the laser beam absorption side. And a composite molded object can be formed by using these molded objects for a laser welding process.

  Examples Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the description of these examples. The material property evaluation method of an Example and a comparative example is shown below.

(1) Formability evaluation Using an injection molding machine (Nissei 60E9ASE), tensile test pieces (ASTM No. 1 type, thickness 3.2 mm) were produced under molding conditions of a cylinder temperature of 260 ° C and a mold temperature of 80 ° C. In the table, “x” in the table indicates that the test piece is deformed when the molded product is ejected or the projecting portion is greatly cramped as a formability defect. On the other hand, those with no deformation are indicated by “◯” in the table.

  Since the test piece for carrying out the other characteristic evaluation was difficult, the subsequent evaluation could not be performed for the sample with “x” which was a molding defect. These are indicated by “−” in the characteristic section of the table.

(2) Evaluation of molding cycle performance With respect to the molding cycle, the gate seal time indicating the solidification rate of the resin in the mold was evaluated. The gate sealing time was defined as the gate sealing time when the test piece was injection-molded and the primary pressure holding time was sequentially extended from the lowest filling pressure and the weight of the molded product was constant. The gate sealing time was measured according to this definition during the injection molding in (1). A material having a short gate seal time has a high solidification rate and is suitable for high cycle molding.

(3) Tensile strength It evaluated by the method based on ASTMD638. The test piece was an ASTM No. 1 type (thickness 3.2 mm), and the molding conditions were a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C.

(4) Bending elastic modulus It evaluated by the method based on ASTM D790. The test piece had a thickness of 3.2 mm, and the molding conditions were a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C.

(5) Impact strength It evaluated by the method based on ASTMD256. A test piece with a width of 3.2 mm was used as the test piece. The molding conditions of the test piece were a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C.

(6) Deflection temperature under load It evaluated by the method based on ASTM D648. The load stress was 1.82 MPa. The test piece had a thickness of 6.4 mm, and the molding conditions were a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C.

(7) Evaluation of cold and heat resistance Molded products obtained by the following method were treated in a 130 ° C environment for 1 hour, then treated in a -40 ° C environment for 1 hour, and then left in a 130 ° C environment, followed by a thermal cycle treatment, and molded. The appearance of the product was visually observed. The number of cycles in which cracks occurred in the insert-molded product was shown in the table, and the magnitude of the value was used as an index for cold resistance.

  The insert molded product is prepared by the following method. FIG. 1A shows a plan view of the insert molded product, and FIG. 1B shows a side view of the molded product. The insert molded product 1 has an insert metal 4 (shown by wavy lines in FIGS. 1A and 1B) mounted and fixed in a mold cavity, and a molten resin is injected so as to cover the insert metal 4. The sprue 3 is molded by an injection molding method for solidifying. The production conditions are a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C.

  The length L1 of the side of the bottom (square) of the quadrangular prism portion of the insert molded product 1 is 50 mm, the height is 30 mm, and the thickness W1 of the resin 2 is 1.5 mm.

(8) Stability heat stability Using an injection molding machine (Toshiba IS80EPN), molding conditions of cylinder temperature 260 ° C., mold temperature 80 ° C., weighing 80 mm, injection pressure 90 MPa, injection time / cooling time = 8/8 seconds The spiral flow length was measured using a spiral flow mold (10 mm width, 2 mm thickness). Molding from 1 shot to 30 shots, when the spiral flow length of the 30th shot is less than -10% lower than that of the 1st shot, "○", when the reduction is over -10% It was written as “×”. A material with a large decrease width means that the residence heat stability during molding is poor, and the viscosity of the material is increased during continuous molding.

(9) Laser beam transmittance evaluation An ultraviolet sphere near infrared spectrophotometer (UV-3100) manufactured by Shimadzu Corporation was used for laser beam transmittance evaluation, and an integrating sphere was used for the detector. The laser beam transmittance was measured by measuring the light transmittance in the near infrared 800 to 1100 nm wavelength region of a sample having a thickness of 3 mm, and the ratio between the transmitted light amount and the incident light amount was expressed in percentage in the table. In the measurement of the laser beam transmittance in the near infrared 800 to 1100 nm wavelength region, the laser beam transmittance is measured every 10 nm, and the maximum value and the minimum value of the laser beam transmittance in the near infrared 800 to 1100 nm wavelength region are obtained. This measurement was performed 5 times, and the average value of the upper limit value and the lower limit value was obtained. Fig.2 (a) is a top view showing a laser beam transmittance | permeability evaluation test piece, (b) is a side view showing the test piece. The laser beam transmittance evaluation test piece 8 was a rectangular parallelepiped with a square bottom, the bottom side L2 being 80 mm, and the thickness D1 being 3 mm. The molding conditions were set to a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C. After injection molding, the mold was cut from the sprue 3, the runner 6, and the gate 7.

(10) Laser weldability evaluation For laser weldability evaluation, Leister's MODULAS C (laser beam wavelength is 940 nm, near infrared, maximum output is 35 W, focal length L is 38 mm, focal diameter D is 0.6 mm) ) Was used to evaluate whether or not welding was performed when a 3 mm-thick test piece was used for the laser beam transmission side sample and when a 3 mm-thick test piece was used. When the melting mark was recognized on the light incident surface of the laser beam transmitting sample, it was indicated as “X”, and when the melting mark was not recognized and welding was possible, it was indicated as “◯”. FIG. 3A is a plan view showing an outline of a laser welding test piece (laser beam absorption side sample) 9, and FIG. 3B is a side view. The laser welding test piece 9 has a width W2 of 24 mm, a length L3 of 70 mm, and a thickness D2 of 3 mm. Further, the laser welding test piece 9 was prepared in the same manner as the laser beam transmission evaluation test piece, and the molding conditions were set to a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C., and cut from the sprue 3, runner 6, and gate 7 after injection molding. Made.

  FIG. 4 is a schematic view showing an outline of the laser welding method. As shown in FIG. 4, the laser welding method is such that the laser beam transmitting side sample 13 is placed on the upper side, a laser welding test piece 14 is placed on the lower side, and the laser beam is irradiated from above. Laser irradiation was performed along the laser welding trajectory 12, and the laser welding conditions were performed under conditions where the best welding strength was obtained in the range of 15 to 35 W output and 1 to 50 mm / sec. The focal length was 38 mm and the focal diameter was fixed at 0.6 mm.

(11) Weld strength For the weld strength measurement, a tensile tester (AG-500B) was used, both ends of the test piece were fixed, and a tensile test was performed so that a tensile shear stress was generated at the weld site. The tensile speed at the time of strength measurement was 1 mm / min, the span was 40 mm, the number of measurements was 5, and the average value was taken as the welding strength. The welding strength was the stress when the welded site was broken. FIG. 5A is a schematic plan view of a laser weld strength measurement test piece laser-welded by the above method, and FIG. 5B is a side view. The laser welding strength measurement test piece 15 was prepared by laminating the laser beam transmission side sample 13 and the laser beam absorption side sample 14 so that the overlapping length L4 was 30 mm and the welding distance Y was 20 mm, and was welded at the laser welding portion 16. Is. In addition, the laser-welded colored resin composition of the present invention is used for the laser beam transmission sample, and 43 parts by weight of glass fiber is added to 100 parts by weight of the polybutylene terephthalate resin to the laser beam absorption side sample. The material which added 0.4 part of was used. The laser beam absorption side sample was manufactured using the same manufacturing method as in the examples.

  The compounding composition used for the Example and the comparative example below is shown.

[Reference Example 1] Polybutylene terephthalate resin (A-1) Polybutylene terephthalate having an intrinsic viscosity of 0.81 dl / g ("Toraycon" 1100S manufactured by Toray Industries, Inc.)
(A-2) Production method of polybutylene terephthalate / isophthalate copolymer 450 parts of terephthalic acid (hereinafter also referred to as TPA), 50 parts of isophthalic acid (hereinafter also referred to as IPA) [TPA / IPA = 90/10 mol%] , 407 parts of 1,4-butanediol and 1 part of tetra-n-butyl titanate were charged into a reactor equipped with a rectification column, and the temperature was gradually raised from 180 ° C. to 230 ° C. in a reduced pressure environment of 500 mmHg. The reaction was carried out to a rate of 95% or more, then the temperature was raised to 240 ° C. and 0.5 mmHg, and the pressure was reduced and the polymerization was completed after 3 hours and 30 minutes to obtain a polybutylene terephthalate copolymer with 10 mol% of isophthalic acid. The intrinsic viscosity of the obtained copolymer was 0.80 dl / g.

[Reference Example 2]
(B-1) Polycarbonate resin “Taflon” A-1900 (viscosity average molecular weight: 19000) manufactured by Idemitsu Petrochemical Co., Ltd.
(B-2) AS resin: acrylonitrile-styrene copolymer (copolymerization ratio of acrylonitrile and styrene: acrylonitrile / styrene = 24/76 (weight ratio), intrinsic viscosity: 0.60 dl / g).

[Reference Example 3] Styrene-based elastomer (C-1) epoxidized styrene-butadiene block copolymer, Epofriend AT504 manufactured by Daicel Chemical Industries, Ltd. (copolymerization ratio of styrene and butadiene: styrene / butadiene = 70/30 ( Weight ratio), epoxy equivalent 1000.
(C-2) Epoxidized styrene-butadiene block copolymer, Epofriend AT501 manufactured by Daicel Chemical Industries, Ltd. (copolymerization ratio of styrene and butadiene: styrene / butadiene = 40/60 (weight ratio), epoxy equivalent 1000) .

[Reference Example 4] Phosphate stabilizer (D-1) ADK STAB AX71 manufactured by Asahi Denka Co.
The mixing ratio of stearyl alcohol phosphate monoester (formula (1)) and stearyl alcohol phosphate diester (formula (2)) is 40:60.
(D-2) The ratio of stearyl alcohol phosphate monoester (formula (1)) and stearyl alcohol phosphate diester (formula (2)) is 30:70.
(D-3) The compounding ratio of stearyl alcohol phosphate monoester (formula (1)) and stearyl alcohol phosphate diester (formula (2)) is 70:30.
(D-4) Daihachi Chemical Trimethyl Phosphate (TMP).

[Reference Example 5] Glass fiber (E-1) Glass fiber “T-120” manufactured by Nippon Electric Glass Co., Ltd. (average fiber diameter: 13 μm, chopped strand having a fiber length of 3 mm).

[Reference Example 6] Crystal nucleating agent (F-1) Talc: hydrous magnesium silicate, apparent specific gravity = 0.20 g / cc, pH = 9.3, average particle size = 5.29 μm.

[Examples 1 to 9], [Comparative Examples 1 to 10]
The manufacturing method of the material described in Examples 1-9 and Comparative Examples 1-10 is as follows. That is, it was manufactured using a twin screw extruder having a screw diameter of 57 mm set at a cylinder temperature of 250 ° C. Component (A) (polybutylene terephthalate resin), component (B) (polycarbonate resin, AS resin), component (C) (styrene elastomer), component (D) (phosphate stabilizer) and other additives are: The component (E) (glass fiber) was supplied from the side feeder through the side feeder and melted and kneaded, and the strand discharged from the die was cooled in a cooling bath, and then pelletized with a strand cutter. Each obtained material was dried for 3 hours with a hot air dryer at 130 ° C., and then molded and evaluated using the method described in the evaluation method.

  The formulation and results of Examples 1 to 9 and Comparative Examples 1 to 10 are shown in Tables 1 and 2. The resin compositions obtained in Examples 1 to 9 each have a high welding strength without generating melting marks on the light incident surface of the laser beam transmitting sample when a 3 mm thick sample is used on the laser beam transmitting side. It was shown that the heat resistance and the heat stability were good. On the other hand, the resin compositions obtained in Comparative Examples 1 to 10 had a laser beam transmittance capable of laser welding, but had insufficient residence heat stability or tensile strength.

(A) is a top view of the insert molded product used for cold-heat resistance evaluation in the Example, (b) is a side view of the molded product. (A) is a laser beam transmittance | permeability evaluation test piece used in the Example, (b) is a side view of the test piece. (A) is a top view of the laser welding test piece used in the Example, (b) is a side view of the test piece. It is the schematic which shows the outline of the laser welding method. (A) is a top view of the laser welding strength measurement test piece used in the Example, (b) is a side view of the test piece.

Explanation of symbols

1. 1. Insert molded product Resin 3. Sprue 4. 4. Insert metal 5. Unfilled part of resin Runner 7. Gate 8. 8. Laser beam transmission evaluation test piece Laser welding specimen 10. Laser beam irradiation unit 11. Laser beam 12. 12. Laser beam trajectory Laser beam transmission side sample 14. Laser beam absorption side sample 15. Test piece for laser welding strength measurement 16. Laser welding part

Claims (5)

(A) polybutylene terephthalate or polybutylene terephthalate resin 50 to 99% by weight composed of polybutylene terephthalate and polybutylene terephthalate copolymer,
(B) A resin composition comprising 1 to 50% by weight of at least one resin selected from polycarbonate resins and acrylonitrile / styrene copolymers,
Furthermore, (C) 1-25 parts by weight of styrene-based elastomer, which is a copolymer of styrene and butadiene, with respect to 100 parts by weight of the total amount of (A) and (B),
(D) A phosphate stabilizer having the following formulas (1) and (2) and a blending ratio of (1) :( 2) = 35: 65 to 45:55 is the sum of (A) and (B). A laser welding resin composition containing 0.01 to 1.0 part by weight with respect to 100 parts by weight.

_(Wherein, R 1, _{R 2} and _{R 3} represents an alkyl group which may have an unsaturated bond having 8 to 30 carbon atoms.) Further, (E) at least one selected from inorganic fillers and organic fillers is added and blended in an amount of 1 to 200 parts by weight per 100 parts by weight of the total amount of (A) and (B). The resin composition for laser welding as described in 1. A molded article comprising the resin composition for laser welding according to claim 1. The molded article according to claim 4, wherein the laser beam transmittance in the near infrared 800 to 1100 nm wavelength region measured at a sample thickness of 3 mm is 10% or more. A composite molded article obtained by laser welding the molded article according to claim 3 or 4.

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