JP2007307913A - Joining method of pipe-shaped article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joining method of a pipe-shaped article, which enables the strong joining of the pipe-shaped article comprising a resin member and a joint comprising a resin member by a laser welding with a laser irradiation. <P>SOLUTION: The method is characterized in that the pipe-shaped article comprising a resin member having an absorbability to the laser is inserted into the joint comprising a resin member having a transparency to the laser, and the laser is irradiated from the joint side and both are laser-welded, and further, is characterized in that a laser absorbing material is arranged on the outer surface of a pipe-shaped article comprising the resin member having the transparency to the laser, the pipe-shaped article is inserted into the joint comprising the resin member having the transparency to the laser, and the laser is irradiated from the joint side, and both are laser-welded. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pipe-shaped product joining method in which a pipe-shaped product made of a resin member and a joint made of a resin member are welded by irradiating a laser beam.

  Conventionally, as a method of joining pipes made of resin members, pressing force with bolts and the like and physical joining using a sealing material, chemical joining by applying a reactive substance and chemically joining, partially dissolving the resin Welding to join is known. Since the long-term reliability of the joint is important for pipe applications, a welding method that easily obtains reliability is preferably used.

As the welding method, heat welding using heat and solvent welding using a resin-soluble solvent are known.
As a heat welding method, there are a butt welding by a hot plate and a method of inserting a pipe into a wire embedded joint and welding them (for example, see Patent Document 1).
However, in butt welding, dripping is likely to occur, and the fragments are peeled off and transported through the pipe to cause clogging, etc., or there is a problem such as pressure loss. It was difficult.
In addition, the electric wire embedded joint has a problem in that its structure is complicated and the cost is high.

Further, as a solvent welding method, there is a method in which a solvent adhesive is applied to the joint surface of a pipe, inserted into a joint, and the solvent is evaporated to join (see, for example, Patent Document 2).
However, there are drawbacks that the solvent to be used is harmful and that the drying time of the adhesive is too long, and there is a problem that sufficient adhesive strength cannot be obtained depending on the type of the resin member.

Japanese Patent Laid-Open No. 9-239839 Japanese National Publication No. 4-506977

  The present invention solves the above-mentioned problems, and a pipe-shaped product joining method capable of firmly joining a pipe-shaped product made of a resin member and a joint made of a resin member by laser welding by irradiating laser light. The issue is to provide.

  In the present invention, a pipe-shaped product made of a resin member that absorbs laser light is inserted into a joint made of a resin member that is transparent to laser light, and laser light is irradiated from the joint side. The present invention relates to a method for joining pipe-shaped products, characterized in that both are laser-welded.

  In the present invention, a laser absorber is disposed on the outer surface of a pipe-shaped article made of a resin member that is transmissive to laser light, and the pipe-shaped article is made of a resin member that is permeable to laser light. It is related with the joining method of the pipe-shaped goods characterized by inserting in the joint which becomes and irradiating a laser beam from the joint side, and laser-welding both.

According to the present invention, a pipe-shaped product made of a resin member and a joint made of a resin member can be firmly joined by laser welding by irradiating laser light.
The laser welding method of the present invention can solve the sagging in the case of conventional heat welding, environmental safety problems due to strong solvents, cost problems, and the difficulty of fusion of thin-walled pipes, and also compared with the case of solvent adhesives And can be suitably used for gas pipes and the like.
In addition, since confidentiality can be increased as compared with a mechanical joining method, it can be suitably used for an automobile fuel pipe, an automobile air brake pipe, and a chemical solution transport pipe.

  First, in the first invention of the present invention, a pipe-shaped product made of a resin member that absorbs laser light is inserted into a joint made of a resin member that is transparent to laser light. Laser welding is performed by irradiating laser light from the side.

The pipe-shaped product in the above invention is made of a resin member that absorbs laser light.
The resin having absorptivity with respect to laser light is not particularly limited as long as it has thermoplasticity, can be formed into a pipe-shaped product such as a gas pipe, and exhibits sufficient absorptivity with respect to laser light. For example, polyolefins such as polyvinyl alcohol, polyvinyl acetate, polyamide, polyethylene, polypropylene, or copolymers such as ethylene and propylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, or styrene, vinyl chloride, methyl methacrylate Absorptive to laser light in resins such as copolymers such as vinylidene chloride, polycarbonate, polyamide, polyester, polyether, polyetherketone, polyetheretherketone, polysulfone, polyimide, and other condensate engineering plastics The thing which mixed the coloring material which has this can be mentioned. In addition, you may use what added reinforcement fibers, such as glass fiber and carbon fiber, as needed.
In particular, a polyamide resin or a polyamide resin composition containing a polyamide resin as a main component is suitably used for automobile pipes that require chemical resistance and toughness, and for combustible gas supply and / or transportation pipes.
Here, sufficient absorptivity means the absorptivity so that the part which received the laser beam absorbs the laser beam, and the part melts.

  Examples of the polyamide resin include those composed of diamine and dibasic acid, or composed of lactam or aminocarboxylic acid, or composed of a copolymer of two or more of these.

Examples of diamines include aliphatic diamines such as tetramethylene diamine, hexamethylene diamine, octamethylene diamine, nonamethyle diamine, undecamethylene diamine, and dodecamethylene diamine, and diamines having aromatic and cyclic structures such as metaxylylene diamine. Can be mentioned.
Examples of the dicarboxylic acid include aliphatic diamines such as adipic acid, heptane dicarboxylic acid, octane dicarboxylic acid, nonane dicarboxylic acid, undecane dicarboxylic acid, and dodecane dicarboxylic acid, and dicarboxylic acids having aromatic / cyclic structures such as terephthalic acid and isophthalic acid. Can be mentioned.

  The lactam is a lactam having 6 to 12 carbon atoms, and the aminocarboxylic acid is an aminocarboxylic acid having 6 to 12 carbon atoms. Examples thereof include 6-aminocaproic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, α-pyrrolidone, ε-caprolactam, ω-laurolactam, and ε-enanthractam.

  In particular, for pipes, a material having a wide processing temperature range and a thermally stable extrudability is preferable. Polyamide 6, polyamide 11, polyamide 12, polyamide 610, polyamide 612 and the like having a relatively low melting point are used. Polymers and copolymers such as polyamide 6/66, polyamide 6/12, polyamide 11/12 are preferably used. Particularly, polyamide 11 and polyamide 12 are desirable in terms of viscosity and water absorption.

The polyamide resin may be a mixture with other polyamide resins or other polymers. The content of the polyamide resin in the mixture is preferably 50% by weight or more.
Polyamide resins to be mixed include polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 612, polyamide 912, polyamide 1010, polyamide 1212, polyamide 6/66 copolymer, polyamide 6/12 copolymer, polyamide 11 / 12 copolymerization. Examples of other polymers include polypropylene, ABS resin, polyphenylene oxide, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, and the like.

  In addition, functional additives such as heat-resistant agents, weathering agents, crystal nucleating agents, crystallization accelerators, mold release agents, lubricants, antistatic agents, flame retardants, and flame retardant aids may be added to the resin. Good.

  Any colorant having such a property can be used as the colorant having absorptivity with respect to laser light in the present invention. Specifically, carbon black, composite oxide pigments can be used. Inorganic colorants such as phthalocyanine pigments and polymethine pigments are used.

The pipe-shaped product made of a resin member that absorbs laser light includes an outer layer made of a resin member that absorbs laser light and a resin member that is transparent to laser light. You may comprise from an inner layer.
The thickness of the outer layer is preferably 10 to 1000 μm.
This is because many laser-absorbing materials also absorb visible light and are colored by blending. However, by setting the thickness of the outer layer made of a resin member having absorbability for laser light to a range of 10 to 1000 μm, The influence of coloring is reduced, and the color of the pipe base material (inner layer) becomes dominant in appearance. Therefore, the apparent color can be controlled by coloring the pipe base material, and the degree of freedom in coloring increases.
Further, by limiting the laser absorption layer to the outer layer, no heat is generated inside, so that it becomes difficult to form a cylindrical dissolution mark on the inner surface of the pipe, and defects in the joint are less likely to occur.

Moreover, the joint in the said invention consists of a resin member which has the permeability | transmittance with respect to a laser beam.
The resin having transparency to laser light is not particularly limited as long as it has thermoplasticity, can be molded into a pipe joint, and the like and exhibits transparency to laser light. For example, polyolefins such as polyvinyl alcohol, polyvinyl acetate, polyamide, polyethylene, polypropylene, or copolymers such as ethylene and propylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, or styrene, vinyl chloride, methyl methacrylate And copolymers such as vinylidene chloride, resins such as condensation engineering plastics such as polycarbonate, polyamide, polyester, polyether, polyetherketone, polyetheretherketone, polysulfone, and polyimide. In addition, you may use what added reinforcement fibers, such as glass fiber and carbon fiber, as needed. Specifically, in consideration of adhesiveness with the pipe-shaped product, it is preferable to use the same type of resin as that used for the pipe-shaped product.
Here, having transparency with respect to laser light means, for example, the transparency with which the remaining laser light is transmitted and the resin of that portion is not melted even if some of the laser light is absorbed.

Functional additives such as heat-resistant agents, weathering agents, mold release agents, lubricants, antistatic agents, flame retardants, and flame retardant aids may be added to the resin.
Moreover, you may add the coloring material which shows the transmittance | permeability with respect to a laser beam to the said resin. Examples thereof include organic dyes such as anthraquinone dyes, perylene series, perinone series, heterocyclic series, disazo series and monoazo series. Further, these dyes may be mixed and used.

In the above invention, a pipe-shaped product made of a resin member that absorbs laser light is inserted into a joint made of a resin member that is transparent to laser light, and laser light is irradiated from the joint side. Both are laser welded.
That is, when irradiated with laser light, the laser light is transmitted through a joint made of a resin member that is transmissive to the laser light, and the transmitted laser light is made of a resin member that is absorbent to the laser light. It reaches the surface of the pipe-shaped product, the laser beam is absorbed at the joining surface, and the pipe-shaped product and the joint to be abutted are melted and joined.

  By joining the pipe-shaped product and the joint by this laser welding method, it is possible to solve the problem of drooping and cost and the difficulty of fusion of the thin-walled pipe. In particular, when the resin is PE, a high molecular weight and high viscosity material can be easily produced, so that dripping does not easily occur. However, in the case of PA, there is an industrially limited increase in viscosity, and further viscosity due to water absorption. This laser welding method is suitable because there is a problem of lowering and sag is likely to occur.

  Next, in the second invention of the present invention, a laser absorbing material is disposed on the outer surface of a pipe-shaped product made of a resin member that is permeable to laser light, and the pipe-shaped product is disposed on the laser light. It inserts in the coupling | bonding which consists of a resin member which has permeability | transmittance, both are laser-welded by irradiating a laser beam from this coupling | bonding side.

The pipe-shaped product in the above invention is made of a resin member that is transparent to laser light.
The resin having transparency to laser light is not particularly limited as long as it has thermoplasticity, can be formed into a pipe-shaped product such as a gas pipe, and exhibits transparency to laser light. For example, polyolefins such as polyvinyl alcohol, polyvinyl acetate, polyamide, polyethylene, polypropylene, or copolymers such as ethylene and propylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, or styrene, vinyl chloride, methyl methacrylate And copolymers such as vinylidene chloride, resins such as condensation engineering plastics such as polycarbonate, polyamide, polyester, polyether, polyetherketone, polyetheretherketone, polysulfone, and polyimide. In addition, you may use what added reinforcement fibers, such as glass fiber and carbon fiber, as needed.

The polyamide resin is the same as in the case of the first invention.
In addition, functional additives such as heat-resistant agents, weathering agents, crystal nucleating agents, crystallization accelerators, mold release agents, lubricants, antistatic agents, flame retardants, and flame retardant aids may be added to the resin. Good.
Moreover, you may add the coloring material which shows the transmittance | permeability with respect to a laser beam to the said resin. Examples thereof include organic dyes such as anthraquinone dyes, perylene series, perinone series, heterocyclic series, disazo series and monoazo series. Further, these dyes may be mixed and used.

Moreover, the joint in the said invention consists of a resin member which has the permeability | transmittance with respect to a laser beam.
The resin having transparency to laser light is not particularly limited as long as it has thermoplasticity, can be molded into a pipe joint, and the like and exhibits transparency to laser light. For example, polyolefins such as polyvinyl alcohol, polyvinyl acetate, polyamide, polyethylene, polypropylene, or copolymers such as ethylene and propylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, or styrene, vinyl chloride, methyl methacrylate And copolymers such as vinylidene chloride, resins such as condensation engineering plastics such as polycarbonate, polyamide, polyester, polyether, polyetherketone, polyetheretherketone, polysulfone, and polyimide. In addition, you may use what added reinforcement fibers, such as glass fiber and carbon fiber, as needed. Specifically, in consideration of adhesiveness with the pipe-shaped product, it is preferable to use the same type of resin as that used for the pipe-shaped product.

Functional additives such as heat-resistant agents, weathering agents, mold release agents, lubricants, antistatic agents, flame retardants, and flame retardant aids may be added to the resin.
Moreover, you may add the coloring material which shows the transmittance | permeability with respect to a laser beam to the said resin. Examples thereof include organic dyes such as anthraquinone dyes, perylene series, perinone series, heterocyclic series, disazo series and monoazo series. Further, these dyes may be mixed and used.

In the said invention, a laser absorber is arrange | positioned in the junction part with the joint of the outer surface of a pipe-shaped goods.
Examples of the laser absorbing material include those obtained by directly applying a coloring material having absorptivity to laser light. Specifically, the coloring material is disposed on the outer surface of the pipe-shaped article by applying a suspension obtained by dispersing the coloring material in a solvent to the outer surface of the pipe-shaped article and drying.
As the colorant having absorptivity with respect to laser light, inorganic colorants such as carbon black and composite oxide pigments, and organic colorants such as phthalocyanine pigments and polymethine pigments are used.

Moreover, the film which consists of a resin member containing the coloring material which has an absorptivity with respect to a laser beam can also be used as a laser absorber.
The resin is not particularly limited as long as it can be formed into a film and exhibits sufficient absorbability with respect to laser light. For example, polyolefins such as polyvinyl alcohol, polyvinyl acetate, polyamide, polyethylene, polypropylene, or copolymers such as ethylene and propylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, or styrene, vinyl chloride, methyl methacrylate Absorptive to laser light in resins such as copolymers such as vinylidene chloride, polycarbonate, polyamide, polyester, polyether, polyetherketone, polyetheretherketone, polysulfone, polyimide, and other condensate engineering plastics The thing which mixed the coloring material which has this can be mentioned. Specifically, it is preferable to use the same type of resin as that used for the pipe-shaped product and the joint in consideration of the adhesiveness to the pipe-shaped product and the joint.
The thickness of the film is preferably 10 to 500 μm. If it is less than 10 μm, breakage is likely to occur at the time of joining a pipe and a joint, and if it exceeds 500 μm, the film becomes rigid and the handling property is deteriorated.

In the above invention, a laser absorber is disposed on the outer surface of a pipe-shaped article made of a resin member that is transparent to laser light, and the pipe-shaped article is made of a resin member that is transparent to laser light. And laser welding is performed by irradiating laser light from the joint side.
That is, when irradiated with laser light, the laser light is transmitted through a joint made of a resin member that is transparent to the laser light, and the transmitted laser light is made of a resin member that is transparent to the laser light. The pipe-shaped product and the joint that are absorbed by the laser absorber disposed on the outer surface of the pipe-shaped product and abut on the joining surface are melted and joined.
According to this laser welding method, since it is not necessary to add a coloring material having absorptivity to laser light to the pipe-shaped product, there is no possibility of coloring or discoloration by this absorbing material, and it is easy to obtain a desired color. Can be colored.

  By joining the pipe-shaped product and the joint by this laser welding method, it is possible to solve dripping, environmental safety problems due to strong solvents, cost problems, and difficulty in fusion of thin-walled pipes. In particular, when the resin is PE, a high molecular weight and high viscosity material can be easily produced, so that dripping does not easily occur. However, in the case of PA, there is an industrially limited increase in viscosity, and further viscosity due to water absorption. This laser welding method is suitable because there is a problem of lowering and sag is likely to occur.

In this invention, you may use the resin member which is weakly absorptive with respect to a laser beam as a coupling in said 1st and 2nd invention.
Here, being weakly absorptive with respect to laser light means being transmissive with respect to laser light, but absorbing a part of the laser light causes the resin in that part to generate heat.
Therefore, when the resin member is irradiated with laser light, the energy is absorbed and heat is generated, and the temperature of the joint surface portion with the pipe-shaped product is increased to some extent. In this state, for example, when a pipe-shaped product made of a resin member that absorbs laser light is melted by absorbing and heating the laser light, the joint resin member is also easily melted. In the portion, the resin members are sufficiently entangled with each other, and the joining force is increased.

  Examples of resin members that are weakly absorbent to laser light include those in which an additive that is weakly absorbent to laser light is added to the resin, or additives that are absorbent to the laser light in the resin. Even if there is absorption, a compounded in a range where the resin does not melt can be used.

  The additive weakly absorbing the laser beam may be any material that resonates with the wavelength of the laser beam, absorbs part of the laser beam, and transmits part of the laser beam. In particular, those having a transmittance of 40 to 90% with respect to laser light are preferable. In addition, the transmittance | permeability with respect to the said laser beam is the numerical value measured about what shape | molded the weak absorption additive in the shape of the ASTM1 dumbbell of thickness 3.2mm.

  Moreover, it is preferable that content of a weakly absorbable additive is 0.1 to 50 weight% with respect to resin. When the content is less than 0.1% by weight, heat generated by absorbing the energy of the laser beam is small, so that the temperature of the resin member is not sufficiently increased, and the bonding strength of the bonded portion is lowered. On the other hand, if the content exceeds 50% by weight, it is not preferable because physical properties such as flexural modulus are lowered and more laser beam energy is required to obtain sufficient welding strength.

  Examples of weakly absorbing additives include copolymers of ethylene and / or propylene with other olefins and vinyl compounds (hereinafter referred to as ethylene and / or propylene copolymers), styrene, and conjugated dienes. Block copolymer formed by hydrogenating copolymer with compound (hereinafter referred to as styrene copolymer), such ethylene and / or propylene copolymer, α, β-unsaturated to styrene copolymer Examples thereof include modified ethylene and / or propylene copolymer and modified styrene copolymer to which carboxylic acid or a derivative thereof is added.

  Examples of the ethylene and / or propylene copolymer include (ethylene and / or propylene) · α-olefin copolymer, (ethylene and / or propylene) · α, β-unsaturated carboxylic acid copolymer, (ethylene And / or propylene) · α, β-unsaturated carboxylic acid ester copolymer, ionomer polymer, and the like.

  (Ethylene and / or propylene) · α-olefin copolymer is a polymer obtained by copolymerizing ethylene and / or propylene and an α-olefin having 3 or more carbon atoms, and as an α-olefin having 3 or more carbon atoms. Are propylene, butene-1, hexene-1, decene-1, 4-methylbutene-1, 4-methylpentene-1.

  The (ethylene and / or propylene) · α, β-unsaturated carboxylic acid copolymer is a polymer obtained by copolymerizing ethylene and / or propylene and an α, β-unsaturated carboxylic acid monomer. Examples of the .beta.-unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, ethacrylic acid, and maleic anhydride.

  (Ethylene and / or propylene) · α, β-unsaturated carboxylic acid ester copolymer is a polymer obtained by copolymerizing ethylene and / or propylene and an α, β-unsaturated carboxylic acid ester monomer. , Α, β-unsaturated carboxylic acid ester monomers include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate and other acrylic esters, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylic acid And methacrylates such as butyl acid.

  The ionomer polymer is obtained by ionizing at least part of the carboxyl group of the olefin and the α, β-unsaturated carboxylic acid copolymer by neutralization of metal ions. Ethylene is preferably used as the olefin, and acrylic acid, methacrylic acid or the like is used as the α, β-unsaturated carboxylic acid. Metal ions can include ions of sodium, potassium, magnesium, calcium, zinc and the like.

  The styrene copolymer is a block copolymer consisting of a polymer block A mainly composed of at least one, preferably 2 or more styrenes, and a polymer block B mainly composed of at least one conjugated diene compound. It is a block copolymer formed by hydrogenating a coalescence, such as ABA, BABA, ABBABA, BABB, and the like. It has a structure.

Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and the like.
Examples of the styrene copolymer include hydrogenated styrene-butadiene-styrene copolymer (SEBS) and hydrogenated styrene-isoprene-styrene copolymer (SEPS).

  The modified (ethylene and / or propylene) -based copolymer and modified styrene-based copolymer are the same as the above-defined (ethylene and / or propylene) -based copolymer and styrene-based copolymer. It can be obtained by adding a compound containing an acid group or a derivative group thereof in a solution state or a molten state. As a method for producing these modified (ethylene and / or propylene) -based copolymers and modified styrene-based copolymers, for example, in an extruder, in the presence of a radical initiator, (ethylene and / or propylene) -based copolymers, There is a method of reacting a styrene copolymer with a compound containing a carboxylic acid group or a derivative group thereof.

  Examples of α, β-unsaturated carboxylic acids or derivatives thereof (hereinafter simply referred to as unsaturated carboxylic acids) include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, and anhydrides or esters of these acids. Can do.

When an additive that absorbs laser light is added to the resin, even when part of the laser light is absorbed when irradiated with the laser light, the remaining laser light is transmitted and the resin in that part is absorbed. The amount of addition is adjusted in such a range that does not melt.
As an additive having absorptivity with respect to laser light, inorganic colorants such as carbon black and composite oxide pigments, and organic colorants such as phthalocyanine pigments and polymethine pigments are used.

In the present invention, as a joint made of a resin member that is weakly absorbable with respect to the laser beam, an inner layer made of a resin member obtained by blending the resin with an additive that is weakly absorbable with respect to the laser beam, In contrast, an outer layer made of a resin member that does not contain weakly absorbent additives or the like may be used.
The thickness of the inner layer is preferably 1/2 or less of the total joint thickness.
By using multiple layers, laser energy loss due to weakly absorbing materials can be reduced, and the required laser light output can be reduced. Therefore, a compact small semiconductor laser can be selected, and it can be handled at a higher scanning speed, which is preferable in terms of apparatus and speed.
In addition, even if physical characteristics change due to the additive, a component that maintains the characteristics of the material itself can be made because the composition ratio of the entire component is small.

In the present invention, as the joint in the first and second inventions, a resin member obtained by blending a resin with a crystal nucleating agent or another resin having a crystallization promoting effect on the resin may be used. .
By blending the resin with a crystal nucleating agent or another resin having a crystallization promoting effect on the resin, the crystallization start temperature of the resin is increased. For this reason, since the crystallization of the first resin starts at the time when the pressure due to volume expansion at the time of melting is high on the joint surface, the resin members are sufficiently intertwined with each other at the joint, and the joint strength is significantly improved. .

  The crystal nucleating agent is not particularly limited as long as it has an effect of increasing the crystallization speed of the resin. For example, graphite, molybdenum disulfide, barium sulfate, calcium carbonate, sodium phosphate, talc, mica, kaolin, etc. Inorganic crystal nucleating agents, fatty acid metal salts composed of fatty acids such as myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid and metals such as zinc, magnesium, calcium, lithium, aluminum, barium, higher fatty acids, And organic crystal nucleating agents such as higher fatty acid esters and higher aliphatic alcohols.

  Moreover, it is preferable that content of a crystal nucleating agent is 0.001-5 weight part with respect to 100 weight part of resin, especially 0.002-1 weight part. When the content is less than 0.001% by weight, the effect of increasing the crystallization start temperature of the resin cannot be obtained, and the bonding strength of the bonded portion is not improved. On the other hand, if the content exceeds 5% by weight, it is not preferable because physical properties such as rigidity, impact resistance and fluidity of the base material change greatly.

  The other resin having an effect of promoting crystallization with respect to the resin is not particularly limited as long as it has an effect of increasing the crystallization speed of the resin, and generally has a freezing point (Tc) higher than the freezing point (Tc) of the resin. What is necessary is just resin which has. For example, when the resin is polyamide 12, examples thereof include polyamide 6 and polyamide 66.

  Moreover, it is preferable that content of the other resin which has a crystallization promotion effect is 1-20 weight part with respect to 100 weight part of resin, especially 5-15 weight part. When the content is less than 1% by weight, the effect of increasing the crystallization start temperature of the resin cannot be obtained, and the bonding strength of the bonded portion is not improved. On the other hand, if the content exceeds 20% by weight, it is not preferable because physical properties such as rigidity, impact resistance and fluidity of the base material change greatly.

In the present invention, the joint includes an inner layer made of a resin member obtained by blending a resin with a crystal nucleating agent or another resin having a crystallization promoting effect, and a crystal nucleating agent or another resin having a crystallization promoting effect. You may comprise from the outer layer which consists of a resin member which does not contain.
The thickness of the inner layer is preferably 1/2 or less of the total joint thickness.
By using multiple layers, laser energy loss due to the addition of a crystal nucleating agent or the like can be reduced, and the required laser light output can be reduced. Therefore, a compact small semiconductor laser can be selected, and it can be handled at a higher scanning speed, which is preferable in terms of apparatus and speed.
In addition, even if physical characteristics change due to the additive, a component that maintains the characteristics of the material itself can be made because the composition ratio of the entire component is small.

As a joint in this invention, a groove | channel and a satin-like fine unevenness | corrugation can also be provided in the inner side which touches a pipe. Providing grooves and fine irregularities is effective in improving pipe insertion and stress relaxation during solidification.
Furthermore, it is necessary for the laser welding surface to be in close contact with each other in order to achieve high adhesive strength, and it is desirable to make the pipe outer diameter larger than the joint inner diameter so that sufficient pressure is applied. For example, it is preferable that the outer diameter of the pipe / the inner diameter of the joint = 1.0 to 1.3.
Further, if necessary, the pipe can be tapered so as to spread from the inside toward the outside (pipe opening), and the pipe can be easily inserted.

Laser light used in the laser welding method of the present invention includes glass: neodymium ³⁺ laser, YAG: neodymium ³⁺ laser, ruby laser, helium-neon laser, krypton laser, argon laser, H ₂ laser, N ₂ laser, semiconductor laser. And so on. A more preferable laser is a semiconductor laser.

  The wavelength of the laser beam varies depending on the resin material to be joined and cannot be determined unconditionally, but is preferably 400 nm or more. If the wavelength is shorter than 400 nm, the resin may be significantly deteriorated.

Further, the output of the laser beam can be adjusted by the scanning speed and the absorption capacity of the transmissive substrate. If the output of the laser beam is low, it becomes difficult to melt the joint surfaces of the resin materials, and if the output is high, the resin material evaporates or changes in quality and the strength is lowered.
This joining method can be used for automobile fuel pipes, automobile air brake pipes, chemical liquid transport pipes, flammable gas supply or transport pipes, and the like.

Hereinafter, the present invention will be described using examples.
Example 1
As shown in FIG. 1, a laser-transmitting cylindrical joint 1 (inner diameter 31.5 mm, thickness 3.5 mm) was produced using polyamide 12 (UBESTA 3035U manufactured by Ube Industries, Ltd.).
Further, a laser-absorbing pipe 2 (an outer diameter of 32 mm and a thickness of 1.5 mm) was prepared using the same polyamide 12 blended with 0.5% by weight of carbon black.
A pipe was inserted into this joint and set in a semiconductor laser device. The irradiation nozzle was moved along the circumference of the joint while irradiating laser light from the joint side. As a result, melting and solidification occurred at the contact surface portion between the joint and the pipe, and the joint and the pipe were firmly welded.
At this time, the laser beam used for laser welding had a wavelength of 808 nm, an output of 30 W, and a scanning speed of 10 mm / s.
In the same manner as described above, the other end of the pipe was laser welded to another joint, and the adhesive strength between the laser welded pipe and the joint was evaluated by pulling out the joint side at both ends in the longitudinal direction. The joint has come off.

Example 2
As shown in FIG. 2, a laser-transmitting cylindrical joint 3 (inner diameter: 31.5 mm, thickness: 3.5 mm) was prepared using polyamide 12 (UBEST 3035U manufactured by Ube Industries, Ltd.).
Also, using the same polyamide 12, a laser transmissive pipe 4 (outer diameter 32 mm, thickness 1.5 mm) was produced.
A carbon black black ink was applied to the outer surface of the pipe 4 and dried, and a laser absorbing material 5 was disposed.
This pipe was inserted into a joint and set in a semiconductor laser device. The irradiation nozzle was moved along the circumference of the joint while irradiating laser light from the joint side. As a result, melting and solidification occurred at the contact surface portion between the joint and the pipe, and the joint and the pipe were firmly welded.
At this time, the laser beam used for laser welding had a wavelength of 808 nm, an output of 30 W, and a scanning speed of 10 mm / s.
When the adhesive force between the laser welded pipe and the joint was evaluated in the same manner as in Example 1, the adhesive force was 3600 N.

Example 3
As shown in FIG. 3, a laser-transmitting cylindrical joint 6 (inner diameter: 31.5 mm, thickness: 3.5 mm) was prepared using polyamide 12 (UBEST 3035U manufactured by Ube Industries, Ltd.).
Further, using the same polyamide 12, a laser permeable pipe 7 (outer diameter 32 mm, thickness 1.5 mm) was produced.
Using the same polyamide 12 blended with 0.5% by weight of carbon black, the melt-extruded film was biaxially stretched to produce a heat-shrinkable film.
The heat-shrinkable film was coated on the outer surface of the pipe 7, heat-treated and adhered to the pipe, and the laser absorbing material 8 was disposed.
This pipe was inserted into a joint and set in a semiconductor laser device. The irradiation nozzle was moved along the circumference of the joint while irradiating laser light from the joint side. As a result, melting and solidification occurred at the contact surface portion between the joint and the pipe, and the joint and the pipe were firmly welded.
At this time, the laser beam used for laser welding had a wavelength of 808 nm, an output of 30 W, and a scanning speed of 10 mm / s.
When the adhesive force between the laser welded pipe and the joint was evaluated in the same manner as in Example 1, the adhesive force was 4000 N.

Example 4
As shown in FIG. 1, a laser-transmitting cylindrical joint 1 (inner diameter 31.5 mm, thickness 3.5 mm) was produced using polyamide 12 (UBESTA 3035U manufactured by Ube Industries, Ltd.).
Also, using the same polyamide 12 mixed with 0.05% by weight of a yellow colorant and an infrared absorber (Avecia PRO-JET830NP), a laser-absorbing pipe 2 (outer diameter 32 mm, thickness 1.5 mm) Was made. The color of the pipe was dark yellow.
A pipe was inserted into this joint and set in a semiconductor laser device. The irradiation nozzle was moved along the circumference of the joint while irradiating laser light from the joint side. As a result, melting and solidification occurred at the contact surface portion between the joint and the pipe, and the joint and the pipe were firmly welded.
At this time, the laser beam used for laser welding had a wavelength of 808 nm, an output of 30 W, and a scanning speed of 10 mm / s.
When the adhesive force between the laser welded pipe and the joint was evaluated in the same manner as in Example 1, the adhesive force was 3900N.

Example 5
As shown in FIG. 4, a laser-permeable cylindrical joint 1 (inner diameter: 31.5 mm, thickness: 3.5 mm) was produced using polyamide 12 (UBESTA 3035U manufactured by Ube Industries, Ltd.).
In addition, the same polyamide 12 blended with 0.05% by weight of a yellow colorant and an infrared absorber (Avecia PRO-JET830NP) in the outer layer and a blend of only the yellow material without the infrared absorber in the inner layer. A laser-absorbing multilayer pipe 2 (outer diameter 32 mm, thickness 1.5 mm) was produced by extrusion. The thickness of the outer layer containing the absorbent was 100 μm, and the appearance of the two-layer pipe was bright yellow.
A pipe was inserted into this joint and set in a semiconductor laser device. The irradiation nozzle was moved along the circumference of the joint while irradiating laser light from the joint side. As a result, melting and solidification occurred at the contact surface portion between the joint and the pipe, and the joint and the pipe were firmly welded.
At this time, the laser beam used for laser welding had a wavelength of 808 nm, an output of 30 W, and a scanning speed of 10 mm / s.
When the adhesive force between the laser welded pipe and the joint was evaluated in the same manner as in Example 1, the adhesive force was 4400 N, which was higher than that of the single-layer pipe. Moreover, the deformation of the welded portion observed on the inner surface was smaller than that of the single layer.

Example 6
As shown in FIG. 1, a laser-permeable cylindrical joint 1 (inner diameter) using polyamide 12 (UBEST 3035U manufactured by Ube Industries Co., Ltd.) and 200 ppm of talc (Talc Cup manufactured by Takehara Chemical Industry Co., Ltd.). 31.5 mm, thickness 3.5 mm).
Further, a laser-absorbing pipe 2 (an outer diameter of 32 mm and a thickness of 1.5 mm) was prepared using the same polyamide 12 blended with 0.5% by weight of carbon black.
A pipe was inserted into this joint and set in a semiconductor laser device. The irradiation nozzle was moved along the circumference of the joint while irradiating laser light from the joint side. As a result, melting and solidification occurred at the contact surface portion between the joint and the pipe, and the joint and the pipe were firmly welded.
At this time, the laser beam used for laser welding had a wavelength of 808 nm, an output of 100 W, and a scanning speed of 10 mm / s.
When the adhesive strength between the laser welded pipe and the joint was evaluated in the same manner as in Example 1, the pipe broke at 5700N.

Example 7
As shown in FIG. 1, a laser-transmitting cylindrical joint 1 (using Ubesta 3035U manufactured by Ube Industries, Ltd.) and 10% by weight of polyamide 6 (1030B manufactured by Ube Industries) was blended. The inner diameter was 31.5 mm and the thickness was 3.5 mm.
Further, a laser-absorbing pipe 2 (an outer diameter of 32 mm and a thickness of 1.5 mm) was prepared using the same polyamide 12 blended with 0.5% by weight of carbon black.
A pipe was inserted into this joint and set in a semiconductor laser device. The irradiation nozzle was moved along the circumference of the joint while irradiating laser light from the joint side. As a result, melting and solidification occurred at the contact surface portion between the joint and the pipe, and the joint and the pipe were firmly welded.
At this time, the laser beam used for laser welding had a wavelength of 808 nm, an output of 100 W, and a scanning speed of 10 mm / s.
When the adhesive strength between the laser welded pipe and the joint was evaluated in the same manner as in Example 1, it was broken at 5700N.

Example 8
As shown in FIG. 1, a laser-permeable cylindrical joint 1 (inner diameter 31) using polyamide 12 (UBEST 3035U manufactured by Ube Industries Co., Ltd.) and 2% by weight of maleic acid-modified EPR (T7712SP manufactured by JSR). 0.5 mm, thickness 3.5 mm).
Further, a laser-absorbing pipe 2 (an outer diameter of 32 mm and a thickness of 1.5 mm) was prepared using the same polyamide 12 blended with 0.5% by weight of carbon black.
A pipe was inserted into this joint and set in a semiconductor laser device. The irradiation nozzle was moved along the circumference of the joint while irradiating laser light from the joint side. As a result, melting and solidification occurred at the contact surface portion between the joint and the pipe, and the joint and the pipe were firmly welded.
At this time, the laser beam used for laser welding had a wavelength of 808 nm, an output of 100 W, and a scanning speed of 10 mm / s.
When the adhesive strength between the laser welded pipe and the joint was evaluated in the same manner as in Example 1, the pipe broke at 5600N.

Example 9
As shown in FIG. 1, a laser-transmitting cylindrical joint 1 using a polyamide 12 (UBEST 3035U manufactured by Ube Industries Co., Ltd.) and 0.005% by weight of an infrared absorber (PRO-JET830NP manufactured by Avecia) is blended. (Inner diameter 31.5 mm, thickness 3.5 mm) was produced.
Further, a laser-absorbing pipe 2 (an outer diameter of 32 mm and a thickness of 1.5 mm) was prepared using the same polyamide 12 blended with 0.5% by weight of carbon black.
A pipe was inserted into this joint and set in a semiconductor laser device. The irradiation nozzle was moved along the circumference of the joint while irradiating laser light from the joint side. As a result, melting and solidification occurred at the contact surface portion between the joint and the pipe, and the joint and the pipe were firmly welded.
At this time, the laser beam used for laser welding had a wavelength of 808 nm, an output of 100 W, and a scanning speed of 10 mm / s.
When the adhesive strength between the laser welded pipe and the joint was evaluated in the same manner as in Example 1, the pipe broke at 5700N.

Example 10
As shown in FIG. 5, polyamide 12 (UBE Kosan Co., Ltd. UBESTA3035U) blended with 200 ppm of talc (Takehara Chemical Industry Co., Ltd. talc cup) in the inner layer, and the one without talc blended in the outer layer, A laser-transmitting cylindrical joint 1 (inner diameter 31.5 mm, thickness: inner layer 0.5 mm, outer layer 3 mm) was produced by injection molding.
Further, a laser-absorbing pipe 2 (an outer diameter of 32 mm and a thickness of 1.5 mm) was prepared using the same polyamide 12 blended with 0.5% by weight of carbon black.
A pipe was inserted into this joint and set in a semiconductor laser device. The irradiation nozzle was moved along the circumference of the joint while irradiating laser light from the joint side. As a result, melting and solidification occurred at the contact surface portion between the joint and the pipe, and the joint and the pipe were firmly welded.
At this time, the laser beam used for laser welding had a wavelength of 808 nm, an output of 50 W, and a scanning speed of 10 mm / s.
When the adhesive strength between the laser welded pipe and the joint was evaluated in the same manner as in Example 1, the pipe broke at 5100N.

FIG. 1 is a schematic view of a joint form of a joint and a pipe produced in Example 1 of the present invention. FIG. 2 is a schematic view of a joint form of a joint and a pipe produced in Example 2 of the present invention. FIG. 3 is a schematic view of the joint form of the joint and pipe produced in Example 3 of the present invention. FIG. 4 is a schematic view of a joint form of a joint and a pipe produced in Example 5 of the present invention. FIG. 5 is a schematic view of a joint form of a joint and a pipe produced in Example 10 of the present invention.

Claims (19)

  A pipe-shaped product made of a resin member that absorbs laser light is inserted into a joint made of a resin member that is transparent to laser light, and both are laser welded by irradiating laser light from the joint side. A method for joining pipe-shaped products.   The pipe-shaped product joining method according to claim 1, comprising an inner layer made of a resin member having transparency to light.   The method for joining pipe-shaped products according to claim 2, wherein the outer layer has a thickness of 10 to 1000 µm.   A laser absorber is disposed on the outer surface of a pipe-shaped article made of a resin member that is transparent to laser light, and the pipe-shaped article is inserted into a joint made of a resin member that is transparent to laser light, A method for joining pipe-shaped products, characterized by irradiating a laser beam from the joint side and laser welding them.   The method for joining pipe-shaped articles according to claim 4, wherein the laser absorbing material is a coloring material having absorbability with respect to laser light.   The method for joining pipe-shaped articles according to claim 4, wherein the laser absorbing material is a film made of a resin member containing a coloring material having absorptivity to laser light.   The method for joining pipe-shaped products according to claim 6, wherein the film has a thickness of 10 to 500 µm.   The pipe-shaped article joining method according to claim 1 or 4, wherein the joint is made of a resin member that is weakly absorbable with respect to laser light.   9. The method for joining pipe-shaped products according to claim 8, wherein the resin member comprises a resin and an additive that is weakly absorbable with respect to laser light.   The method for joining pipe-shaped articles according to claim 9, wherein the weakly absorbing additive has a transmittance of 40 to 90% with respect to the laser beam.   The weakly absorbing additive is at least one of ethylene and / or propylene copolymer, styrene copolymer, modified ethylene and / or propylene copolymer and modified styrene copolymer, The method for joining pipe-shaped products according to claim 9.   9. The pipe-shaped product according to claim 8, wherein the resin member is formed by adding an additive having an absorptivity to the laser beam to the resin in such a range that the resin does not melt even if the laser beam is absorbed. Joining method.   The method for joining pipe-shaped products according to claim 1 or 4, wherein the resin member constituting the joint is formed by blending a crystal nucleating agent with resin.   The pipe-shaped product joining method according to claim 13, wherein the content of the crystal nucleating agent is 0.001 to 5 parts by weight with respect to 100 parts by weight of the resin.   14. The method for joining pipe-shaped products according to claim 13, wherein the crystal nucleating agent is talc.   The pipe-shaped article joining method according to claim 1 or 4, wherein the resin member constituting the joint is formed by blending the resin with another resin having an effect of promoting crystallization with respect to the resin.   The pipe-shaped product joining method according to claim 16, wherein the content of another resin having a crystallization promoting effect is 1 to 20 parts by weight with respect to 100 parts by weight of the resin.   The pipe-shaped article joining method according to claim 1, wherein the pipe member and the resin member constituting the joint are made of a polyamide resin or a polyamide resin composition containing polyamide as a main component.   The pipe-shaped article joining method according to claim 1, wherein the pipe-shaped article is for an automobile fuel pipe, an automobile air brake pipe, a chemical transportation pipe, a flammable gas supply or transportation pipe.

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