JP2020023127A - Multi-layer pipe, and multi-layer pipe connector - Google Patents

Abstract

To provide a multi-layer pipe which has excellent adhesion reliability and weatherability, has high flat strength, and can be used under pressure.SOLUTION: The multi-layer pipe, according to the present invention, includes an inner layer and an outer layer. A material of the inner layer includes a thermoplastic resin. When the outer layer is immersed in a specific mixed liquid at 23°C for 30 min., and then, the outer layer after immersion is dried at 60°C for 72 hr, the yield strength at 23°C of the outer layer after drying is 10 MPa or more. When obtaining a laminate including a first test piece obtained by molding a material of the outer layer, a second test piece obtained by molding polyvinyl chloride, and an adhesive layer arranged between the first test piece and the second test piece, and formed of a vinyl chloride-based adhesive material, the adhesion strength at 23°C of the first test piece and the second test piece in the laminate is 10 MPa or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a multilayer pipe having an inner layer and an outer layer. In addition, the present invention relates to a multilayer pipe connector using the multilayer pipe.

  In buildings such as condominiums, apartments, and detached houses, plastic piping is often used to supply and drain water. When the pipe is used outdoors or when it is necessary to prevent oxygen from permeating the pipe, a pipe in which an inner layer and an outer layer formed of a highly functional resin composition are integrated is used. ing. For example, pipes that can be used outdoors are known because the inner layer is a vinyl chloride resin (PVC resin) and the outer layer is a resin having excellent weather resistance.

  Further, when the required length of the piping structure is longer than the length of one piping, or when the piping structure has a bend or the like, a plurality of pipings are connected directly or via a joint. In this case, an adhesive layer may be formed on the end of the pipe with an adhesive, and the pipe may be connected by the adhesive layer.

  Patent Literature 1 below discloses a vinyl chloride resin pipe in which the outer periphery of a pipe body is covered with an outer layer. The pipe body is formed of a mixed resin composition of a chlorinated vinyl chloride resin and a vinyl chloride resin. The outer layer is formed of an acrylic-vinyl chloride copolymer resin composition obtained by graft-polymerizing a vinyl chloride monomer to an acrylic copolymer.

  In Patent Document 2 below, a pair of pipes having an inner layer portion formed in a tubular shape and an outer layer portion having higher weather resistance than the inner layer portion, a pipe joint formed at an end of each pipe, A pipe connection structure including a joint in which a pipe joint is inserted from both ends and an adhesive layer provided between the pipe joint and the joint is disclosed. At the pipe joint in the pipe connection structure, the outer layer of the pipe is not provided and the inner layer is exposed.

JP-A-2002-254576 JP-A-2006-188696

  In a conventional pipe as described in Patent Literature 1, weather resistance is increased to some extent by forming an outer layer with a specific resin. Further, in a conventional pipe as described in Patent Document 1, an outer surface of a first plastic pipe and an inner surface of a second plastic pipe are bonded to each other via an adhesive layer formed of an adhesive material. , The first and second plastic tubes are connected to each other. However, in the conventional piping, the adhesion between the first plastic tube and the second plastic tube is poor, and sufficient adhesion reliability may not be obtained. In particular, when the material of the first plastic tube is different from the material of the second plastic tube, it is difficult to obtain sufficient bonding reliability. As a result, when the internal pressure increases due to water flow or the like, the connected pipe may be disconnected.

  In Patent Literature 2, in order to enhance the bonding reliability, the pipe and the joint are connected by peeling the outer layer of the pipe to expose the inner layer and providing an adhesive layer on the surface of the exposed inner layer. However, this method requires a lot of work for construction. In addition, if the outer layer is not sufficiently peeled off at the time of construction, sufficient adhesion reliability may not be obtained.

  Further, in conventional pipes as described in Patent Documents 1 and 2, when the pipe is deformed due to an external pressure or the like, the pipe is damaged, and the outer layer is cracked or cracked.

  An object of the present invention is to provide a multilayer pipe and a multilayer pipe connector having excellent adhesion reliability and weather resistance, and having high flat strength and which can be used under pressure.

  According to a wide aspect of the present invention, there is provided a multi-layer tube to which a member to be connected is connected and used, which includes an inner layer and an outer layer, wherein the material of the inner layer includes a thermoplastic resin, and the outer layer is formed of 20% by weight of methyl ethyl ketone. %, 40% by weight of tetrahydrofuran, and 40% by weight of cyclohexanone after immersion at 23 ° C. for 30 minutes, and then drying the outer layer after immersion at 60 ° C. for 72 hours. A yield strength at 23 ° C. of 10 MPa or more, a first test piece molded with the material of the outer layer, a second test piece molded with polyvinyl chloride, the first test piece, When obtaining a laminate including an adhesive layer formed of a vinyl chloride-based adhesive material and disposed between the second test piece and the first test piece and the second test in the laminate, At 23 ° C with a piece Chakukyodo is more than 10 MPa, the multilayer tube is provided.

  In a specific aspect of the multilayer tube according to the present invention, the yield strength at 40 ° C. of the outer layer after drying is 10 MPa or more, and the first test piece and the second test piece in the laminate are Has an adhesive strength at 40 ° C. of 10 MPa or more.

  In a specific aspect of the multilayer tube according to the present invention, the yield strength at 60 ° C. of the outer layer after drying is 10 MPa or more, and the first test piece and the second test piece in the laminate are Has an adhesive strength at 60 ° C. of 10 MPa or more.

  In a specific aspect of the multilayer tube according to the present invention, the total light transmittance in the thickness direction of the outer layer is 50% or less, or the total light transmittance per 0.1 mm thickness of the outer layer is 50% or less. It is.

  In a specific aspect of the multilayer tube according to the present invention, the nominal diameter is 50A, and after performing an impact resistance test in accordance with JIS K6741 or JIS K6742, a 50% impact breaking height in accordance with JIS K7211 was calculated. Sometimes, the 50% impact fracture height is 100 cm or more.

  In a specific aspect of the multilayer tube according to the present invention, when a weather resistance test is performed, the 50% impact fracture height after the weather resistance test is performed, and the 50% impact fracture height before the weather resistance test is performed. Is 50% or more.

  In a specific aspect of the multilayer tube according to the present invention, when a weather resistance test is performed, a color difference before and after the weather resistance test is 10 or less.

  In a specific aspect of the multilayer pipe according to the present invention, when performing a flattening test in which the outer diameter of the multilayer pipe is reduced to 準 拠 in accordance with JIS K6741, cracks or cracks may occur in the multilayer pipe. Absent.

  In one specific aspect of the multilayer tube according to the present invention, the material of the outer layer is polymethyl methacrylate, acrylonitrile-styrene resin, acrylonitrile-styrene-acrylate resin, acrylonitrile-acrylic rubber-styrene resin, and acrylonitrile-ethylene-propylene. -It contains at least one kind of weather resistant thermoplastic resin among styrene resins, and the content of the weather resistant thermoplastic resin is 50% by weight or more based on 100% by weight of the material of the outer layer.

  In a specific aspect of the multilayer tube according to the present invention, the degree of polymerization of the weather-resistant thermoplastic resin is 500 or more and 2000 or less.

  In a specific aspect of the multilayer tube according to the present invention, the material of the outer layer includes at least one component of rubber, a thermoplastic elastomer, and a plasticizer, and the component is included in 100% by weight of the material of the outer layer. Is 5% by weight or more and 50% by weight or less.

  In a specific aspect of the multilayer tube according to the present invention, the material of the outer layer contains an inorganic pigment, and the inorganic pigment has an average particle diameter of 100 nm or more and 800 nm or less.

  According to a broad aspect of the present invention, a multilayer pipe including an inner layer and an outer layer, a connection target member connected to the multilayer pipe, and an adhesive layer disposed between the multilayer pipe and the connection target member The material of the inner layer in the multilayer tube includes a thermoplastic resin, and the outer layer in the multilayer tube is immersed in a solvent in the material of the adhesive layer at 23 ° C. for 30 minutes. When dried at 60 ° C. for 72 hours, the yield strength at 23 ° C. of the outer layer after drying is 10 MPa or more, and the adhesive strength at 23 ° C. between the multilayer pipe and the member to be connected is 10 MPa or more. A multilayer pipe connection is provided.

  In a specific aspect of the multilayer pipe connection body according to the present invention, the yield strength at 40 ° C. of the outer layer after drying is 10 MPa or more, and the adhesive strength between the multilayer pipe and the member to be connected at 40 ° C. Is 10 MPa or more.

  In a specific aspect of the multilayer pipe connector according to the present invention, the yield strength at 60 ° C. of the outer layer after drying is 10 MPa or more, and the adhesive strength between the multilayer pipe and the member to be connected at 60 ° C. Is 10 MPa or more.

  In a specific aspect of the multilayer tube connector according to the present invention, the solvent in the material of the adhesive layer is obtained by immersing the outer layer in the multilayer tube in the solvent at 23 ° C. for 10 minutes, and then immersing the outer layer. Is a solvent that increases the weight increase calculated by the following formula (1) by 1.25 times or more when dried.

  Weight increase = (weight of outer layer after immersion−weight of outer layer after drying + weight of outer layer before immersion) / weight of outer layer before immersion (1)

  In a specific aspect of the multilayer pipe connection body according to the present invention, when a hot internal pressure creep test is performed at 23 ° C. and a hoop stress of 6.4 MPa, the time until water leakage occurs is reduced by the hot internal pressure creep. 100 hours or more from the start of the test.

  In a specific aspect of the multilayer pipe connection body according to the present invention, when a hot internal pressure creep test is performed at 40 ° C. and a hoop stress of 6.4 MPa, the time until water leakage occurs is determined by the hot internal pressure creep. 100 hours or more from the start of the test.

  In a specific aspect of the multilayer pipe connector according to the present invention, when a hot internal pressure creep test is performed at 60 ° C. and a hoop stress of 6.4 MPa, the time until water leakage occurs is determined by the hot internal pressure creep. 100 hours or more from the start of the test.

  In a specific aspect of the multilayer tube connector according to the present invention, the total light transmittance in the thickness direction of the outer layer in the multilayer tube is 50% or less, or the outer layer thickness in the multilayer tube is 0.1 mm or less. The total light transmittance per unit is 50% or less.

  In a specific aspect of the multilayer pipe connector according to the present invention, the multilayer pipe has a nominal diameter of 50A, and after performing an impact resistance test based on JIS K6741 or JIS K6742 on the multilayer pipe, based on JIS K7211. When the calculated 50% impact fracture height is calculated, the 50% impact fracture height is 100 cm or more.

  In a specific aspect of the multilayer pipe connection body according to the present invention, when a weather resistance test is performed on the multilayer pipe, the 50% impact breaking height after the weather resistance test is performed, and The impact strength retention with respect to the 50% impact fracture height is 50% or more.

  In a specific aspect of the multilayer pipe connection body according to the present invention, when a weather resistance test is performed on the multilayer pipe, a color difference before and after the weather resistance test is 10 or less.

  In a specific aspect of the multilayer pipe connection body according to the present invention, when the flat pipe is subjected to a flattening test in which the outer diameter of the multilayer pipe is reduced to 準 拠 in accordance with JIS K6741, No cracks or cracks in the tube.

  In a specific aspect of the multilayer pipe connector according to the present invention, the material of the outer layer in the multilayer pipe is polymethyl methacrylate, acrylonitrile-styrene resin, acrylonitrile-styrene-acrylate resin, acrylonitrile-acryl rubber-styrene resin, And at least one weatherable thermoplastic resin of acrylonitrile-ethylene-propylene-styrene resin, wherein the content of the weatherable thermoplastic resin is 50% by weight in 100% by weight of the material of the outer layer in the multilayer tube. That is all.

  In a specific aspect of the multilayer pipe connector according to the present invention, the degree of polymerization of the weather-resistant thermoplastic resin is 500 or more and 2000 or less.

  In a specific aspect of the multilayer pipe connector according to the present invention, the material of the outer layer in the multilayer pipe includes at least one component of rubber, a thermoplastic elastomer, and a plasticizer, and In 100% by weight of the material of the outer layer, the content of the component is 5% by weight to 50% by weight.

  In a specific aspect of the multilayer tube connector according to the present invention, the material of the outer layer in the multilayer tube includes an inorganic pigment, and the inorganic pigment has an average particle size of 100 nm or more and 800 nm or less.

  The multilayer pipe according to the present invention is a multilayer pipe used by connecting members to be connected. The multilayer pipe according to the present invention includes an inner layer and an outer layer. In the multilayer tube according to the present invention, the material of the inner layer contains a thermoplastic resin. In the multilayer tube according to the present invention, the outer layer is immersed in a mixed solution containing 20% by weight of methyl ethyl ketone, 40% by weight of tetrahydrofuran, and 40% by weight of cyclohexanone at 23 ° C. for 30 minutes. When dried at 60 ° C. for 72 hours, the yield strength at 23 ° C. of the outer layer after drying is 10 MPa or more. Regarding the multilayer tube according to the present invention, a first test piece molded with the material of the outer layer, a second test piece molded with polyvinyl chloride, the first test piece and the second test piece And an adhesive layer formed of a vinyl chloride-based adhesive material. In the multilayer tube according to the present invention, the adhesive strength at 23 ° C. between the first test piece and the second test piece in the laminate is 10 MPa or more. Since the multilayer pipe according to the present invention has the above-described configuration, it has excellent adhesion reliability and weather resistance, has a high flat strength, and can be used under pressure.

  A multilayer pipe connector according to the present invention includes a multilayer pipe including an inner layer and an outer layer, a connection target member connected to the multilayer pipe, and an adhesive layer disposed between the multilayer pipe and the connection target member. Is provided. In the multilayer pipe connection body according to the present invention, the material of the inner layer in the multilayer pipe includes a thermoplastic resin. In the multilayer-pipe connector according to the present invention, the outer layer in the multilayer pipe is immersed in a solvent of the material for the adhesive layer at 23 ° C. for 30 minutes, and the outer layer after immersion is dried at 60 ° C. for 72 hours. Furthermore, the yield strength at 23 ° C. of the outer layer after drying is 10 MPa or more. In the multilayer pipe connection body according to the present invention, the adhesive strength between the multilayer pipe and the connection target member at 23 ° C. is 10 MPa or more. Since the multilayer pipe connector according to the present invention has the above-described configuration, it has excellent adhesion reliability and weather resistance, has high flat strength, and can be used under pressure.

FIG. 1 is a sectional view showing a multilayer pipe according to one embodiment of the present invention. FIG. 2 is a sectional view showing a multilayer pipe connector according to one embodiment of the present invention.

  Hereinafter, the present invention will be described in detail.

  The multilayer pipe according to the present invention is a multilayer pipe used by connecting members to be connected. The multilayer pipe according to the present invention includes an inner layer and an outer layer. In the multilayer tube according to the present invention, the material of the inner layer contains a thermoplastic resin. In the multilayer tube according to the present invention, the outer layer is immersed in a mixed solution containing 20% by weight of methyl ethyl ketone, 40% by weight of tetrahydrofuran, and 40% by weight of cyclohexanone at 23 ° C. for 30 minutes. When dried at 60 ° C. for 72 hours, the yield strength at 23 ° C. of the outer layer after drying is 10 MPa or more. Regarding the multilayer tube according to the present invention, a first test piece molded with the material of the outer layer, a second test piece molded with polyvinyl chloride, the first test piece and the second test piece And an adhesive layer formed of a vinyl chloride-based adhesive material. In the multilayer tube according to the present invention, the adhesive strength at 23 ° C. between the first test piece and the second test piece in the laminate is 10 MPa or more.

  A multilayer pipe connector according to the present invention includes a multilayer pipe including an inner layer and an outer layer, a connection target member connected to the multilayer pipe, and an adhesive layer disposed between the multilayer pipe and the connection target member. Is provided. In the multilayer pipe connection body according to the present invention, the material of the inner layer in the multilayer pipe includes a thermoplastic resin. In the multilayer-pipe connector according to the present invention, the outer layer in the multilayer pipe is immersed in a solvent of the material for the adhesive layer at 23 ° C. for 30 minutes, and the outer layer after immersion is dried at 60 ° C. for 72 hours. Furthermore, the yield strength at 23 ° C. of the outer layer after drying is 10 MPa or more. In the multilayer pipe connection body according to the present invention, the adhesive strength between the multilayer pipe and the connection target member at 23 ° C. is 10 MPa or more.

  Since the multilayer pipe and the multilayer pipe connector according to the present invention have the above-described configuration, they have excellent adhesion reliability and weather resistance, and have high flat strength, and can be used under pressure. it can.

  ADVANTAGE OF THE INVENTION The multilayer pipe and the multilayer pipe connector which concern on this invention are excellent in adhesive reliability, and can improve the connectivity in the axial direction of the multilayer pipe connector of the said multilayer pipe sufficiently. ADVANTAGE OF THE INVENTION Since the multilayer pipe and multilayer pipe connector which concern on this invention are excellent in adhesive reliability, it improves both the adhesive strength (short-term connection reliability) and creep strength (long-term connection reliability) of a multilayer pipe connector. Can be.

  Since the multilayer pipe and the multilayer pipe connector according to the present invention are excellent in weather resistance, the mechanical strength of the multilayer pipe and the multilayer pipe connector is maintained high even when the multilayer pipe and the multilayer pipe connector are used outdoors. And excellent adhesion reliability can be maintained.

  Further, since the multilayer pipe and the multilayer pipe connector according to the present invention have a high flat strength, even if the diameter of the multilayer pipe and the multilayer pipe connector is increased, deformation due to the weight of the multilayer pipe can be suppressed, and The adhesion reliability between the pipe and the member to be connected can be sufficiently improved.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. In the drawings, the size, thickness, shape, and the like may be different from the actual size, thickness, shape, and the like for convenience of illustration.

  FIG. 1 is a sectional view showing a multilayer pipe according to one embodiment of the present invention.

  The multilayer pipe 1 shown in FIG. 1 is used by being connected to a member to be connected. Specifically, a connection target member such as another pipe or a pipe joint is connected to an end of the multilayer pipe 1. The end of the multilayer tube 1 is a connection region for connecting a connection target member. The connection target member may be a single pipe or a multilayer pipe.

  The multilayer tube 1 includes an inner layer 11 and an outer layer 12. The inner layer 11 is tubular. The inner layer 11 reaches both ends of the multilayer tube 1.

  The outer layer 12 is disposed on an outer surface of the inner layer 11. The outer layer 12 is arranged on the entire outer surface of the inner layer 11. The outer layer preferably reaches both ends of the multilayer tube. The outer layer is preferably arranged in a tubular shape.

  FIG. 2 is a sectional view showing a multilayer pipe connector according to one embodiment of the present invention.

  The multilayer pipe connector 21 includes the multilayer pipe 1 shown in FIG. 1, a connection target member 31, and an adhesive layer 41.

  The adhesive layer 41 is disposed between the multilayer tube 1 and the connection target member 31. The adhesive layer 41 is disposed on the outer surface of the outer layer 12 and on the inner surface of the connection target member 31.

  The adhesive layer 41 is disposed on the outer surface of the outer layer 12 at the end of the multilayer tube 1. The adhesive layer 41 is disposed on the outer surface of the outer layer 12 so as to reach the end 1 a of the multilayer tube 1. The adhesive layer 41 is disposed on the inner surface of the connection target member 31 at the end of the connection target member 31. The adhesive layer 41 is arranged on the inner surface of the connection target member 31 so as to reach the end 1 a of the connection target member 31.

  The adhesive layer only needs to be disposed on the outer surface of the outer layer, and may not be disposed on the outer surface of the outer layer at the end of the multilayer tube. The adhesive layer may be disposed on the entire outer surface of the outer layer, or may be disposed on a part of the outer surface of the outer layer. The adhesive layer may not be disposed on the entire outer surface of the outer layer up to the end of the multilayer tube at the end of the multilayer tube, or may be disposed in a partial region of the end of the multilayer tube. Good. The adhesive layer may be exposed from the end of the connection target member on the multilayer tube side, or may not be exposed from the end of the connection target member on the multilayer tube side.

  The adhesive layer may be disposed on the inner surface of the connection target member, and may not be disposed on the inner surface of the connection target member at the end of the connection target member. The adhesive layer may be disposed on the entire inner surface of the connection target member, or may be disposed on a part of the inner surface of the connection target member. The adhesive layer may not be disposed on the entire outer surface of the outer layer up to the end of the connection target member at the end of the connection target member, but is disposed in a partial region of the end of the multilayer tube. You may. The adhesive layer may be exposed from the end of the multilayer tube on the connection target member side, or may not be exposed from the end of the multilayer tube on the connection target member side.

  The multilayer pipe 1 and the connection target member 31 are connected at an end of the multilayer pipe 1. The multilayer pipe 1 and the connection target member 31 are connected via an adhesive layer 41.

[Multilayer pipe and multilayer pipe in multilayer pipe connector]
The multilayer pipe according to the present invention is suitably used by connecting members to be connected. A multilayer pipe in a multilayer pipe and a multilayer pipe connector according to the present invention includes an inner layer and an outer layer. In the multilayer pipe and the multilayer pipe in the multilayer pipe connector according to the present invention, the inner layer is tubular, and the outer layer is disposed on an outer surface of the inner layer. The inner layer is a layer located inside the outer layer, and is a tube main body. The outer layer is a layer located outside the inner layer. The multilayer tube according to the present invention may have a two-layer structure, may have a three-layer structure, or may have a structure having three or more layers. The outer layer is preferably the outermost layer (outermost layer) of the multilayer tube. When the outer layer is not the outermost layer of the multilayer tube, a layer having a thickness of 3 mm or less may be disposed on the outer surface of the outer layer. Further, the outer layer is preferably a layer having weather resistance.

(Inner layer)
The material of the inner layer of the multilayer pipe according to the present invention and the material of the inner layer of the multilayer pipe in the multilayer pipe connector according to the present invention include a thermoplastic resin. Only one kind of the thermoplastic resin may be used, or two or more kinds may be used in combination.

  Examples of the thermoplastic resin include polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), and polyvinylidene fluoride (PVDF).

  The thermoplastic resin is preferably polyvinyl chloride (PVC) from the viewpoint of further improving the weather resistance of the multilayer pipe and the multilayer pipe connector.

  The polyvinyl chloride (PVC) is not particularly limited. As the polyvinyl chloride (PVC), a conventionally known vinyl chloride resin can be used. Examples of the vinyl chloride resin include a homopolymer of a vinyl chloride monomer, a copolymer of a vinyl chloride monomer and a monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer, and polymers and copolymers other than vinyl chloride. Examples include a graft polymer in which vinyl chloride is graft-polymerized to a polymer. The vinyl chloride resin may be used alone or in combination of two or more.

  The monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer is not particularly limited, and is an α-olefin compound such as ethylene, propylene, or butylene; a vinyl ester compound such as vinyl acetate or vinyl propionate; butyl vinyl ether or cetyl Vinyl ether compounds such as vinyl ether; (meth) acrylate compounds such as methyl (meth) acrylate, ethyl (meth) acrylate and butyl (meth) acrylate; aromatic vinyl compounds such as styrene and α-methylstyrene; and N-phenyl And N-substituted maleimide compounds such as maleimide and N-cyclohexylmaleimide. As the monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer, only one kind may be used, or two or more kinds may be used in combination.

  The polymer and the copolymer for graft copolymerizing vinyl chloride are not particularly limited, and ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer, ethylene-ethyl acrylate copolymer, ethylene- Examples thereof include butyl acrylate-carbon monoxide copolymer, acrylonitrile-butadiene copolymer, polyurethane, chlorinated polyethylene, and chlorinated polypropylene. As the polymer and copolymer for graft copolymerizing vinyl chloride, only one kind may be used, or two or more kinds may be used in combination.

  The content of the structural unit derived from vinyl chloride is preferably 40% by weight or more in 100% by weight of the vinyl chloride resin.

  The polymerization degree of the vinyl chloride resin is preferably 100 or more, and more preferably 10,000 or less. If the degree of polymerization of the vinyl chloride resin is not less than the lower limit, long-term performance such as fatigue characteristics is not easily impaired. When the degree of polymerization of the vinyl chloride resin is not more than the above upper limit, it is not necessary to lower the temperature at the time of molding, and the processability is further improved.

  The vinyl chloride resin may be used in combination with other organic materials as long as the effects of the present invention are not impaired. For example, in order to further improve the mechanical strength, an acrylic resin or the like may be used in combination with the vinyl chloride resin.

  Further, the vinyl chloride resin may be a post-chlorinated vinyl chloride resin.

  The content of the thermoplastic resin in 100% by weight of the material of the inner layer is preferably 90% by weight or more, more preferably 95% by weight or more, and most preferably 100% by weight (total amount). Therefore, the material of the inner layer is most preferably a thermoplastic resin.

  In 100% by weight of the material of the inner layer, the content of the polyvinyl chloride (PVC) is preferably 90% by weight or more, more preferably 95% by weight or more, and most preferably 100% by weight (total amount). Therefore, the material of the inner layer is most preferably polyvinyl chloride (PVC).

  The tensile elongation at break of the inner layer at 23 ° C. is preferably 10% or more, more preferably 15% or more. When the tensile elongation at break of the inner layer at 23 ° C. is equal to or more than the lower limit, the flattening strength can be further increased, and even when a pressure due to an external impact or the like is applied to the multilayer pipe and the multilayer pipe connection body, the multilayer structure can be improved. Cracking and breakage of the pipe and the multilayer pipe connection body can be effectively prevented.

  The tensile elongation at break of the inner layer at 23 ° C. is measured according to JIS K6815-2. The test piece for measuring the tensile elongation at break may be obtained by cutting out the inner layer from the multilayer pipe, or may be obtained by molding the material of the inner layer.

  The tensile breaking strain at 23 ° C. of the inner layer is preferably 10% or more, more preferably 15% or more. When the tensile breaking strain at 23 ° C. of the inner layer is equal to or more than the lower limit, the flattening strength can be further increased, and even when pressure due to external impact or the like is applied to the multilayer pipe and the multilayer pipe connector from outside, the multilayer pipe is In addition, the multilayer pipe connector can effectively prevent cracking and breakage.

  The tensile breaking strain at 23 ° C. of the inner layer is measured in accordance with JIS K7161-1. The test piece for measuring the tensile breaking strain may be obtained by cutting an inner layer from a multilayer pipe, or may be obtained by molding a material of the inner layer.

(Outer layer)
From the viewpoint of improving the adhesion reliability, the outer layer of the multilayer tube according to the present invention is an outer layer satisfying the following configurations A and B.

  Structure A: A mixed liquid containing 20% by weight of methyl ethyl ketone, 40% by weight of tetrahydrofuran, and 40% by weight of cyclohexanone in 100% by weight of a mixed liquid (hereinafter, sometimes referred to as a mixed liquid (1)) is prepared. After immersing the outer layer in the liquid mixture (1) at 23 ° C. for 30 minutes, and drying the immersed outer layer at 60 ° C. for 72 hours, the dried outer layer (hereinafter, the dried outer layer (1)) The yield strength at 23 ° C. is 10 MPa or more.

  Configuration B: A first test piece in which the material of the outer layer is molded is prepared. A second test piece molded with polyvinyl chloride is prepared. A laminate provided between the first test piece and the second test piece and having an adhesive layer formed of a vinyl chloride adhesive material (hereinafter sometimes referred to as an adhesive material (1)); A body (1) is prepared. The laminate (1) includes a first test piece, an adhesive layer, and a second test piece in this order. The adhesive strength of the first test piece and the second test piece in the laminate (1) at 23 ° C. is 10 MPa or more.

  Specifically, the laminate (1) applies an adhesive material (1) to at least one of the surface of the first test piece and the surface of the second test piece, and , And the second test piece.

  In addition, the liquid mixture (1) and the adhesive material (1) are prepared for measuring the yield strength in the configuration A and the adhesive strength in the configuration B. The adhesive material (1) may be used, or an adhesive material different from the adhesive material (1) may be used to produce the multilayer pipe connector.

  From the viewpoint of improving the adhesion reliability, the outer layer of the multilayer pipe in the multilayer pipe connection body according to the present invention is an outer layer satisfying the following configurations C and D.

  Configuration C: After immersing the outer layer in a solvent for the material of the adhesive layer (adhesive material) at 23 ° C. for 30 minutes, and drying the immersed outer layer at 60 ° C. for 72 hours, the dried outer layer ( Hereinafter, the dried outer layer (2) may be described)) has a yield strength at 23 ° C of 10 MPa or more.

  Configuration D: The adhesive strength at 23 ° C. between the multilayer tube and the connection target member is 10 MPa or more.

  From the viewpoint of further improving the adhesion reliability, the yield strength at 23 ° C. of the outer layer (1) after drying is preferably 35 MPa or more.

  From the viewpoint of further improving the adhesion reliability, the yield strength at 40 ° C. of the outer layer (1) after drying is preferably 10 MPa or more, more preferably 20 MPa or more.

  From the viewpoint of further improving the adhesion reliability, the yield strength at 60 ° C. of the outer layer (1) after drying is preferably 10 MPa or more, more preferably 12 MPa or more.

  From the viewpoint of further improving the adhesion reliability, the yield strength at 23 ° C. of the outer layer (2) after drying is preferably 35 MPa or more.

  From the viewpoint of further improving the adhesion reliability, the yield strength at 40 ° C. of the outer layer (2) after drying is preferably 10 MPa or more, more preferably 20 MPa or more.

  From the viewpoint of further improving the adhesion reliability, the yield strength at 60 ° C. of the outer layer (2) after drying is preferably 10 MPa or more, more preferably 12 MPa or more.

  The yield strength at 23 ° C., 40 ° C. and 60 ° C. of the outer layer (1) after drying and the outer layer (2) after drying is measured in accordance with JIS K6815-2 or JIS K7161-1. The test piece for measuring the yield strength may be obtained by cutting out an outer layer from a multilayer pipe, or may be obtained by molding a material of the outer layer.

  From the viewpoint of further improving the bonding reliability, the bonding strength at 23 ° C. between the first test piece and the second test piece in the laminate (1) is preferably 15 MPa or more.

  From the viewpoint of further improving the adhesive reliability, the adhesive strength of the first test piece and the second test piece at 40 ° C. in the laminate (1) is preferably 10 MPa or more, more preferably 15 MPa or more. It is.

  From the viewpoint of further improving the adhesive reliability, the adhesive strength of the first test piece and the second test piece in the laminate (1) at 60 ° C. is preferably 10 MPa or more, more preferably 15 MPa or more. It is.

  From the viewpoint of further improving the bonding reliability, the bonding strength between the multilayer tube and the member to be connected at 23 ° C. is preferably 15 MPa or more.

  From the viewpoint of further improving the bonding reliability, the bonding strength between the multilayer tube and the member to be connected at 40 ° C. is preferably 10 MPa or more, more preferably 15 MPa or more.

  From the viewpoint of further improving the bonding reliability, the bonding strength between the multilayer tube and the member to be connected at 60 ° C. is preferably 10 MPa or more, more preferably 15 MPa or more.

  23 ° C., 40 ° C. and 60 ° C. adhesive strength between the first test piece and the second test piece in the laminate (1), and 23 ° C. between the multilayer pipe and the member to be connected. The bond strength at 40 ° C. and 60 ° C. is an indicator of short-term bond reliability.

  A measurement sample for measuring the adhesive strength at 23 ° C., 40 ° C., and 60 ° C. between the multilayer pipe and the member to be connected can be obtained as follows.

  A first test piece in which the material of the outer layer of the multilayer pipe is molded and a second test piece in which the material of the inner surface of the member to be connected is molded. The material of the adhesive layer (adhesive material) is applied to at least one of the surface of the first test piece and the surface of the second test piece. The first test piece and the second test piece are overlapped to obtain a measurement sample (laminate (2)). In the obtained laminate (2), an adhesive layer formed of the adhesive layer material (adhesive material) is disposed between the first test piece and the second test piece. In addition, the said laminated body (2) may be obtained by cutting out a multilayer pipe connector.

  The above adhesive strength can be measured as follows.

  The obtained laminate (1) and the measurement sample (laminate (2)) are subjected to a tensile test under the conditions of 23 ° C., 40 ° C. or 60 ° C. and a tensile speed of 5 mm / min. From the breaking load when the laminate breaks and the bonding area of the first test piece and the second test piece, the adhesive strength can be determined by the following equation. As the tensile tester, for example, "Desktop Precision Universal Tester AGX-X" manufactured by Shimadzu Corporation can be used.

Adhesive strength (MPa) = Breaking load (N) / Adhesive area (mm ² )

  The tensile elongation at break of the outer layer at 23 ° C. is preferably 10% or more, more preferably 15% or more. When the tensile elongation at break of the outer layer at 23 ° C. is equal to or higher than the lower limit, the flattening strength can be further increased, and even when pressure due to external impact or the like is applied to the multilayer pipe and the multilayer pipe connector from the outside, the multilayer Cracking and breakage of the pipe and the multilayer pipe connection body can be effectively prevented.

  The tensile elongation at break of the outer layer at 23 ° C. is measured according to JIS K6815-2. The test piece for measuring the tensile elongation at break may be obtained by cutting an outer layer from a multilayer pipe, or may be obtained by molding a material of the outer layer.

  The tensile breaking strain at 23 ° C. of the outer layer is preferably 10% or more, more preferably 15% or more. When the tensile rupture strain at 23 ° C. of the outer layer is equal to or more than the lower limit, the flattening strength can be further increased, and even when pressure due to external impact or the like is applied to the multilayer pipe and the multilayer pipe connector from outside, the multilayer pipe is In addition, the multilayer pipe connector can effectively prevent cracking and breakage.

  The tensile breaking strain at 23 ° C. of the outer layer is measured according to JIS K7161-1. The test piece for measuring the tensile breaking strain may be obtained by cutting an outer layer from a multilayer pipe, or may be obtained by molding the material of the outer layer.

  In the multilayer tube, the total light transmittance in the thickness direction of the outer layer is preferably 50% or less, or the total light transmittance per 0.1 mm thickness of the outer layer is preferably 50% or less. When the total light transmittance is equal to or less than the upper limit, the total amount of light reaching the inner layer can be reduced, so that the weather resistance of the multilayer tube can be improved, and the impact resistance of the multilayer tube can be increased. be able to.

  The total light transmittance in the thickness direction of the outer layer and the total light transmittance per 0.1 mm thickness of the outer layer can be determined by measuring the total light transmittance of the outer layer. The outer layer for measuring the total light transmittance may be obtained by cutting the outer layer from the multilayer tube, and forming a material having the same thickness as the outer layer in the multilayer tube by molding the material of the outer layer. May be obtained by

  From the viewpoint of further improving the weather resistance and impact resistance of the multilayer tube, the total light transmittance in the thickness direction of the outer layer is preferably less than 50%, more preferably 40% or less, and further preferably 30% or less. is there.

  From the viewpoint of further improving the weather resistance and impact resistance of the multilayer tube, the total light transmittance of the outer layer per 0.1 mm thickness is preferably less than 50%, more preferably 40% or less, and further preferably 30% or less. % Or less.

  The total light transmittance is measured according to JIS K7361-1.

  It is preferable that the material of the outer layer contains a thermoplastic resin from the viewpoint of further improving adhesion reliability, weather resistance and flat strength. The thermoplastic resin is preferably a thermoplastic resin having weather resistance (weather-resistant thermoplastic resin). Only one kind of the thermoplastic resin may be used, or two or more kinds may be used in combination.

  Regarding whether or not the thermoplastic resin has weather resistance, when the following weather resistance test is performed, when the color difference before and after the weather resistance test is 10 or less, the thermoplastic resin has weather resistance. I judge it. In addition, the resin after the above-mentioned weather resistance test is equivalent to the resin after being left outdoors for about 10 years.

  The weather resistance test is performed for 800 hours under the following conditions using "METALWEATHER" manufactured by Daipla Wintes.

Operation mode: L + D
L: Irradiation intensity 75 mW / cm ² , black panel temperature 50 ° C, humidity 50%, 4 hours D: No irradiation, black panel temperature 30 ° C, humidity 98%, 4 hours Shower: 30 seconds before and after D each

  The color difference is obtained by measuring the L, a, b values of the resin before and after the weather resistance test based on JIS-Z8730 using a color difference meter “NR-300” manufactured by Nippon Denshoku Industries Co., Ltd. ΔE calculated as follows.

ΔE = [(ΔL) ² + (Δa) ² + (Δb) ² ] ^1/2

  Examples of the weather-resistant thermoplastic resin include polymethyl methacrylate (PMMA), acrylonitrile-styrene resin (AS resin), acrylonitrile-styrene-acrylate resin (ASA resin), acrylonitrile-acryl rubber-styrene resin (AAS resin), and acrylonitrile. -Ethylene-propylene-styrene resin (AES resin), and polyimide resin.

  From the viewpoint of further improving the adhesion reliability, weather resistance and flattening strength, the material of the outer layer is made of polymethyl methacrylate (PMMA), acrylonitrile-styrene resin (AS resin), acrylonitrile-styrene-acrylate resin (ASA resin). ), Acrylonitrile-acrylic rubber-styrene resin (AAS resin), and acrylonitrile-ethylene-propylene-styrene resin (AES resin).

  As used herein, the term “polymethyl methacrylate, acrylonitrile-styrene resin, acrylonitrile-styrene-acrylate resin, acrylonitrile-acrylic rubber-styrene resin, and acrylonitrile-ethylene-propylene-styrene resin of at least one type of weatherable heat The "plastic resin" may be referred to as "weather-resistant thermoplastic resin A".

  The content of the weather-resistant thermoplastic resin in 100% by weight of the material of the outer layer is preferably 50% by weight or more, more preferably 60% by weight or more, and further preferably 70% by weight or more.

  The content of the weather-resistant thermoplastic resin A in 100% by weight of the material of the outer layer is preferably 50% by weight or more, more preferably 60% by weight or more, and further preferably 70% by weight or more.

  The degree of polymerization of the above-mentioned weatherable thermoplastic resin is preferably 500 or more, more preferably 600 or more, preferably 2000 or less, more preferably 1800 or less, and further preferably 1500 or less. When the degree of polymerization of the weather-resistant thermoplastic resin is equal to or higher than the lower limit, adhesion reliability and weather resistance can be further improved. When the degree of polymerization of the weather-resistant thermoplastic resin is equal to or less than the upper limit, the molding temperature can be kept low, and the processability can be enhanced.

  The degree of polymerization of the weatherable thermoplastic resin A is preferably 500 or more, more preferably 600 or more, preferably 2000 or less, more preferably 1800 or less, and further preferably 1500 or less. When the degree of polymerization of the weather-resistant thermoplastic resin A is equal to or higher than the lower limit, adhesion reliability and weather resistance can be further improved. When the degree of polymerization of the weather-resistant thermoplastic resin A is equal to or less than the upper limit, the molding temperature can be suppressed low, and the processability can be improved.

  From the viewpoint of further increasing the flattening strength, it is preferable that the material of the outer layer contains at least one component of rubber, thermoplastic elastomer, and plasticizer.

  In this specification, “at least one component of rubber, thermoplastic elastomer, and plasticizer” may be referred to as “component X”.

  Therefore, the material of the outer layer preferably contains the component X. As the component X, only one type may be used, or two or more types may be used in combination.

  Examples of the rubber include butadiene rubber, nitrile rubber (NBR), ethylene propylene diene rubber (EPDM), silicone rubber, acrylic rubber, and fluoro rubber (FKM). As the rubber, only one kind may be used, or two or more kinds may be used in combination.

  As the thermoplastic elastomer, α-olefin copolymer (EAO), styrene-butadiene copolymer (SB or SBS), styrene-ethylenebutylene-styrene copolymer (SEBS), styrene-isoprene copolymer (SI or SIS), ethylene-alkyl acrylate Copolymer, ethylene-vinyl acetate (EVA), ethylene-acrylic acid copolymer (EAA), ionomer resin, elastomer copolyester, ethylene-methyl acrylic acid copolymer (EMAA), polynorbornene, ESI, thermoplastic polyurethane (TPU), polyether -Amide block copolymer, EVA-carbon monoxide copolymer (EVACO), MAH-modified polyethylene, maleic anhydride-modified EVA, glycidyl methacrylate Modified EMA, glycidyl methacrylate modified EBA, and glycidyl methacrylate modified EVA, and the like. As the thermoplastic elastomer, only one kind may be used, or two or more kinds may be used in combination.

  The EAO preferably has a linear structure.

  Examples of the ethylene-alkyl acrylate copolymer include ethylene-methyl acrylate (EMA), ethylene-butyl acrylate (EBA), and ethylene-ethyl acrylate (EEA).

  The thermoplastic elastomer is preferably EVA, EVACO, EMA, EBA, or EAA from the viewpoint of further improving the adhesive reliability and the flattening strength.

  Examples of the plasticizer include dibutyl phthalate, di-2-ethylhexyl phthalate, and di-2-ethylhexyl adipate. The plasticizer may be used alone or in combination of two or more.

  In 100% by weight of the material of the outer layer, the content of the component X is preferably 5% by weight or more, more preferably 8% by weight or more, further preferably 10% by weight or more, preferably 50% by weight or less, more preferably It is at most 45% by weight, more preferably at most 40% by weight. When the content of the component X is equal to or more than the lower limit, the flattening strength can be further improved. When the content of the component X is equal to or less than the upper limit, the adhesion reliability can be further improved.

  From the viewpoint of further improving the weather resistance, the material of the outer layer preferably contains an inorganic pigment.

  Examples of the inorganic pigment include zinc oxide, cobalt oxide, iron oxide, carbon black, antimony oxide, titanium oxide, chromium oxide, lead chromate molybdate, calcium carbonate, and zinc sulfide. One kind of the above-mentioned inorganic pigment may be used alone, or two or more kinds may be used in combination.

  From the viewpoint of effectively suppressing heat generation of the inorganic pigment due to light absorption, the inorganic pigment preferably contains titanium oxide.

  The average particle size of the inorganic pigment is preferably 100 nm or more, more preferably 120 nm or more, preferably 800 nm or less, more preferably 750 nm or less. When the average particle size of the inorganic pigment is equal to or larger than the lower limit, the weather resistance can be further improved, and the mechanical properties can be favorably maintained over a long period of time. When the average particle size of the inorganic pigment is equal to or less than the upper limit, the tensile elongation at break of the outer layer can be improved.

  The average particle size of the inorganic pigment indicates a number average particle size. The average particle size of the inorganic pigment is determined, for example, by performing a laser diffraction particle size distribution measurement on the inorganic pigment. After the outer layer of the multilayer tube is cut out, the inorganic pigment is separated by dissolving the outer layer with a solvent or the like, and the separated inorganic pigment is measured by laser diffraction particle size distribution measurement.

  Based on 100 parts by weight of the weather-resistant thermoplastic resin in the material of the outer layer, the content of the inorganic pigment in the material of the outer layer is preferably 0.1 part by weight or more, and preferably 30 parts by weight or less. . When the content of the inorganic pigment is equal to or more than the lower limit, the weather resistance can be further improved. When the content of the inorganic pigment is equal to or less than the upper limit, mechanical properties such as creep performance and flat strength can be further improved.

  After performing an impact resistance test on the multilayer pipe having a nominal diameter of 50A, when calculating a 50% impact fracture height, the 50% impact fracture height is preferably 100 cm or more, and more preferably 130 cm or more. More preferably, it is still more preferably 150 cm or more. When the 50% impact fracture height is not less than the lower limit, cracking or cracking of the multilayer pipe caused by external force applied to the multilayer pipe during construction or the like can be effectively suppressed.

  The impact resistance test is measured in accordance with JIS K6741 or JIS K6742. Specifically, the impact resistance test is measured according to Annex JA of JIS K6741 or Annex JA of JIS K6742. The 50% impact fracture height is calculated in accordance with JIS K7211.

  When the weather resistance test shown below was performed on the multilayer pipe, the impact strength retention rate of the 50% impact fracture height after the weather resistance test was performed with respect to the 50% impact fracture height before the weather resistance test was performed was as follows: It is preferably at least 50%, more preferably at least 60%, even more preferably at least 80%. When the impact strength retention is equal to or greater than the lower limit, the mechanical properties of the multilayer pipe can be maintained over a longer period.

  The impact strength retention can be determined by the following equation.

  Impact strength retention (%) = (50% impact fracture height after weather resistance test / 50% impact fracture height before weather resistance test) × 100

  The weather resistance test is performed for 800 hours under the following conditions using "METALWEATHER" manufactured by Daipla Wintes. The multilayer pipe after the weather resistance test was performed corresponds to the multilayer pipe after being left outdoors for about 10 years.

Operation mode: L + D
L: Irradiation intensity 75 mW / cm ² , black panel temperature 50 ° C, humidity 50%, 4 hours D: No irradiation, black panel temperature 30 ° C, humidity 98%, 4 hours Shower: 30 seconds before and after D each

  When the above-mentioned weather resistance test is performed on the multilayer pipe, it is preferable that a color difference before and after the weather resistance test is 10 or less. When the color difference is equal to or less than the upper limit, the weather resistance can be further improved.

  The color difference is obtained by measuring the L, a, b values of the resin before and after the weather resistance test based on JIS-Z8730 using a color difference meter “NR-300” manufactured by Nippon Denshoku Industries Co., Ltd. ΔE calculated as follows.

ΔE = [(ΔL) ² + (Δa) ² + (Δb) ² ] ^1/2

  From the viewpoint of further increasing the flattening strength, when a flattening test for compressing the multilayered pipe until the outer diameter of the multilayered pipe is reduced to Ｊ in accordance with JIS K6741 is performed, the multilayered pipe may be cracked or cracked. Preferably do not occur.

  From the viewpoint of practical use, and from the viewpoint of improving hydraulic properties and workability, the outer diameter of the multilayer pipe is preferably 10 mm or more, more preferably 15 mm or more, preferably 600 mm or less, more preferably 400 mm or less. It is.

  From the viewpoint of practical use, the thickness of the multilayer tube is preferably 2 mm or more, more preferably 2.5 mm or more, preferably 20 mm or less, more preferably 15 mm or less.

  The thickness of the inner layer is preferably 1.5 mm or more, more preferably 2 mm or more, preferably 20 mm or less, more preferably 15 mm or less, from the viewpoint of practical use and improving the weather resistance.

  From the viewpoints of practical use and improving weather resistance, the thickness of the outer layer is preferably 0.02 mm or more, more preferably 0.04 mm or more, preferably 0.5 mm or less, and more preferably 0.5 mm or less. 4 mm or less.

  The nominal diameter of the multilayer tube may be 50A, or may not be 50A. When the nominal diameter of the multilayer tube is 50A, it is preferable that the outer diameter and the thickness of the multilayer tube conform to the VP standard of JIS K6741.

  In the multilayer pipe, a layer different from the inner layer and the outer layer may be arranged between the inner layer and the outer layer. The layer different from the inner layer and the outer layer is not particularly limited, and examples thereof include a thermoplastic resin layer, a fiber reinforced resin layer, a gas barrier layer, a metal layer, and an adhesive layer. Can be appropriately selected and combined.

  Examples of the material of the thermoplastic resin layer include an olefin resin and a vinyl chloride resin. Examples of the olefin resin include polyethylene, polypropylene, polybutene, an ethylene-vinyl acetate copolymer, and an ethylene-α-olefin copolymer.

  Examples of the fiber reinforced resin layer include a layer in which a thermoplastic resin and reinforcing fibers are combined. The reinforcing fiber may be an inorganic fiber or an organic fiber. Examples of the inorganic fibers include glass fibers, carbon fibers, silicon-titanium-carbon fibers, boron fibers, and fine metal fibers. Examples of the organic fibers include aramid fibers, vinylon fibers, polyester fibers, and polyamide fibers. These reinforcing fibers, when continuous fibers are arranged in the longitudinal direction, when continuous fibers arranged in the longitudinal direction and continuous fibers that are orthogonal or intersecting with the continuous fibers are arranged, as well as fibers of finite length Used when placed.

  Various additives may be used in the multilayer tube as needed. Examples of the additives include stabilizers, stabilization aids, lubricants, processing aids, impact modifiers, heat resistance improvers, antioxidants, ultraviolet absorbers, light stabilizers, fillers, pigments, and the like. . One type of the above additives may be used alone, or two or more types may be used in combination.

  The stabilizer is not particularly limited, and examples thereof include a heat stabilizer and a heat stabilization aid. The heat stabilizer is not particularly limited, and examples thereof include an organotin-based stabilizer, a lead-based stabilizer, a calcium-zinc-based stabilizer, a barium-zinc-based stabilizer, and a barium-cadmium-based stabilizer. As the organic tin-based stabilizer, dibutyltin mercapto, dioctyltin mercapto, dimethyltin mercapto, dibutyltin mercapto, dibutyltin malate, dibutyltin malate polymer, dioctyltin malate, dioctyltin malate polymer, dibutyltin laurate, and And dibutyltin laurate polymers. Only one kind of the heat stabilizer may be used, or two or more kinds thereof may be used in combination.

  The heat stabilizing aid is not particularly limited, and includes, for example, epoxidized soybean oil, phosphate, polyol, hydrotalcite, and zeolite. Only one kind of the heat stabilizing aid may be used, or two or more kinds thereof may be used in combination.

  Examples of the lubricant include an internal lubricant and an external lubricant. The internal lubricant is used for the purpose of lowering the flow viscosity of the molten resin at the time of molding and preventing frictional heating. The internal lubricant is not particularly limited, and examples thereof include butyl stearate, lauryl alcohol, stearyl alcohol, epoxy soybean oil, glycerin monostearate, stearic acid, and bisamide. The external lubricant is used for the purpose of enhancing the sliding effect between the molten resin and the metal surface during molding. The external lubricant is not particularly limited, and examples thereof include paraffin wax, polyolefin wax, ester wax, and montanic acid wax. One of the above lubricants may be used alone, or two or more thereof may be used in combination.

  The processing aid is not particularly limited, and examples thereof include an acrylic processing aid. Examples of the acrylic processing aid include an alkyl acrylate-alkyl methacrylate copolymer having a weight average molecular weight of 100,000 to 2,000,000, and specifically, an n-butyl acrylate-methyl methacrylate copolymer, and Examples thereof include 2-ethylhexyl acrylate-methyl methacrylate-butyl methacrylate copolymer. One of the above processing aids may be used alone, or two or more thereof may be used in combination.

  The impact modifier is not particularly limited, and examples thereof include methyl methacrylate-butadiene-styrene copolymer (MBS), chlorinated polyethylene, and acrylic rubber. Only one impact modifier may be used, or two or more impact modifiers may be used in combination.

  The heat resistance improver is not particularly limited, and examples thereof include an α-methylstyrene-based resin and an N-phenylmaleimide-based resin. One kind of the above-mentioned heat-resistant improver may be used alone, or two or more kinds may be used in combination.

  The antioxidant is not particularly limited, and examples include a phenolic antioxidant. One of the above antioxidants may be used alone, or two or more thereof may be used in combination.

  The UV absorber is not particularly limited, and examples thereof include a salicylate UV absorber, a benzophenone UV absorber, a benzotriazole UV absorber, and a cyanoacrylate UV absorber. The ultraviolet absorber may be used alone or in combination of two or more.

  The light stabilizer is not particularly limited, and examples thereof include a hindered amine light stabilizer. As the light stabilizer, only one kind may be used, or two or more kinds may be used in combination.

  The filler is not particularly limited, and includes calcium carbonate, talc, and the like. As the filler, only one kind may be used, or two or more kinds may be used in combination.

  The pigment is not particularly limited, and includes an organic pigment and an inorganic pigment. Examples of the organic pigment include an azo organic pigment, a phthalocyanine organic pigment, a sulene organic pigment, and a dye lake organic pigment.

(Adhesive layer)
The adhesive layer is formed of an adhesive material. The material (adhesive material) of the adhesive layer contains a solute and a solvent. The solute and the solvent may be used alone or in combination of two or more.

  In the present invention, since a specific adhesive layer material (adhesive material) is used, when the adhesive material is applied on the outer surface of the outer layer, the outer surface of the outer layer can be swollen. As a result, the insertion resistance at the time of connecting the multilayer pipe and the connection target member can be reduced, and the bonding reliability between the multilayer pipe and the connection target member can be improved.

  Examples of the solute include a thermoplastic resin and the like. Examples of the thermoplastic resin include acrylonitrile-butadiene-styrene resin (ABS resin), acrylonitrile-ethylene-propylene-styrene resin (AES resin), acrylonitrile-styrene-acrylate resin (ASA resin), polyethylene terephthalate (PET), and polychlorinated resin. Examples include vinyl (PVC), chlorinated vinyl chloride resin (CPVC), polymethyl methacrylate (PMMA), a rubber-containing acrylic resin, and a copolymer of vinyl chloride and vinyl acetate.

  From the viewpoint of further swelling the outer surface of the outer layer, the adhesive material preferably contains polyvinyl chloride or chlorinated vinyl chloride resin as the solute.

  Examples of the solvent include methyl ethyl ketone, tetrahydrofuran, cyclohexanone, acetone, cyclohexane, ethyl acetate, and ethanol.

  From the viewpoint of further swelling the outer surface of the outer layer, the adhesive material preferably contains methyl ethyl ketone, tetrahydrofuran, cyclohexanone, or acetone as the solvent.

  From the viewpoint of further swelling the outer surface of the outer layer, the content of the solute in 100% by weight of the adhesive material is preferably 5% by weight or more, more preferably 10% by weight or more, and preferably 30% by weight or less. , More preferably 25% by weight or less.

  From the viewpoint of further swelling the outer surface of the outer layer, the content of the solvent in 100% by weight of the adhesive material is preferably 70% by weight or more, more preferably 75% by weight or more, and preferably 95% by weight or less. , More preferably 90% by weight or less.

  The solvent in the material of the adhesive layer (adhesive material) is obtained by immersing the outer layer in the multilayer tube in the solvent at 23 ° C. for 10 minutes, and then drying the outer layer after immersion. The solvent is preferably a solvent that increases the weight increase calculated by 1.25 times or more, more preferably a solvent that increases the amount by 1.30 times or more, and further preferably a solvent that increases the amount by 1.40 times or more. preferable. The solvent in the material (adhesive material) of the adhesive layer is calculated by the following formula (1) when the outer layer is immersed in the solvent at 23 ° C. for 10 minutes, and the immersed outer layer is dried. The solvent is preferably a solvent whose weight increase is 2.00 times or less, and more preferably 1.80 times or less. In this case, the outer surface of the outer layer can be swollen, and as a result, the insertion resistance when connecting the multilayer pipe and the connection target member can be reduced, and the connection accuracy between the multilayer pipe and the connection target member can be increased. it can. When the weight increase calculated by the following equation (1) exceeds 2.00 times, the solvent is sufficiently dried after bonding the multilayer tube and the connection target member as compared with the case where the weight increase is 2.00 times or less. Time until the connection becomes longer, the connection strength may be reduced, or the connection may fall back.

  Weight increase = (weight of outer layer after immersion−weight of outer layer after drying + weight of outer layer before immersion) / weight of outer layer before immersion (1)

  After the outer layer of the multilayer tube among the solvent components contained in the solvent in the material (adhesive material) of the adhesive layer is immersed in the solvent component at 23 ° C. for 10 minutes, the outer layer after immersion is dried. Then, the solvent component that makes the weight increase calculated by the above formula (1) 1.25 times or more is referred to as a first solvent.

  The solvent in the material (adhesive material) of the adhesive layer preferably includes the first solvent. In this case, the outer surface of the outer layer can be swollen, and as a result, the insertion resistance when connecting the multilayer pipe and the connection target member can be reduced, and the connection accuracy between the multilayer pipe and the connection target member is increased. be able to.

  From the viewpoint of further improving the connection accuracy, the first solvent is a solvent that makes the weight increase calculated by the above formula (1) preferably 1.30 times or more, more preferably 1.40 times or more. It is preferred that From the viewpoint of maintaining the strength of the multilayer pipe and the multilayer pipe connector at a high level, the first solvent increases the weight increase calculated by the above formula (1) by preferably 2.00 times or less, more preferably 1% or less. It is preferable that the solvent is 80 times or less. When the weight increase calculated by the above formula (1) exceeds 2.00 times, the solvent is sufficiently dried after bonding the multilayer pipe and the connection target member as compared with the case where the weight increase is 2.00 times or less. Time may be prolonged, the connection strength may be reduced, or the connection may fall back.

  In 100% by weight of the adhesive material, the content of the first solvent (total content when a plurality of first solvents is used) is preferably 45% by weight or more, more preferably 50% by weight or more, It is more preferably at least 55% by weight, preferably at most 90% by weight, more preferably at most 88% by weight. When the content of the solvent is not less than the lower limit and not more than the upper limit, the insertion resistance when connecting the multilayer pipe and the connection target member can be further reduced, and the connection accuracy between the multilayer pipe and the connection target member is further improved. Can be enhanced.

  The adhesive material is preferably a vinyl chloride adhesive material (vinyl chloride adhesive). The vinyl chloride adhesive material contains vinyl chloride or chlorinated vinyl chloride resin.

  From the viewpoint of favorably using the multilayer pipe and the multilayer pipe connector at a temperature of 40 ° C. or higher, the adhesive material preferably contains a chlorinated vinyl chloride resin. An adhesive material containing a chlorinated vinyl chloride resin (vinyl chloride-based adhesive material) can enhance heat resistance.

  In addition, in the multilayer pipe according to the present invention, as shown in the configuration B, the laminate (1) is manufactured using the vinyl chloride-based adhesive material (the adhesive material (1)). The solute in the adhesive material (1) is preferably a chlorinated vinyl chloride resin. The solvent in the adhesive material (1) is preferably the mixed liquid (1) used in the above-described configuration A. In the adhesive material (1), the chlorinated vinyl chloride resin is preferably a solute, and the mixed solution (1) is preferably a solvent.

  In the multilayer pipe connector according to the present invention, the material (adhesive material) of the adhesive layer may be the adhesive material (1) or may not be the adhesive material (1). The liquid mixture (1) and the adhesive material (1) are prepared for measuring the yield strength in the above-described configuration A and the adhesive strength in the above-described configuration B.

  Commercially available products can also be used as the adhesive material. Commercial products of the above-mentioned adhesive materials include “Eslon Adhesive No. 73S” and “Eslon Adhesive No. 100S” manufactured by Sekisui Chemical Co., Ltd.

  From the viewpoint of further improving the bonding reliability, it is preferable that the length of the bonding layer in the axial direction of the multilayer tube is the same as the insertion length specified for the member to be connected. For example, when connecting a multi-layer pipe having a nominal diameter of 50A and a TS socket as a connection target member, the insertion length specified for the connection target member is 63 mm. In this case, the length of the adhesive layer in the axial direction of the multilayer tube is preferably 63 mm. In addition, when the said adhesive layer is arrange | positioned at the both ends of the both sides of a multilayer pipe, the said length means the length in one adhesive layer.

(Connection target member)
The connection target member means a member that is used by being connected to the multilayer pipe. The member to be connected is not particularly limited as long as it is a member used by being connected to the multilayer pipe, and examples thereof include a pipe (second pipe) and a pipe joint. Examples of the pipe include a single-layer pipe and a multi-layer pipe.

  The material of the connection target member is not particularly limited. Examples of the material of the connection target member include polyvinyl chloride (PVC) and polyvinylidene fluoride (PVDF). As the material of the connection target member, only one type may be used, or two or more types may be used in combination.

  The polyvinyl chloride may be a rigid polyvinyl chloride.

  The material of the connection target member may include the material of the outer layer, or may not include the material of the outer layer.

  The material of the connection target member may be polyvinyl chloride, or may not be polyvinyl chloride. The material of the connection target member may be hard vinyl chloride. The polyvinyl chloride used in the configuration B is used for producing the second test piece in the laminate (1).

  Examples of the connection target member include a TS socket. The nominal diameter of the TS socket may be 50A.

(Other details of multi-layer pipe connection)
A multilayer pipe connector according to the present invention includes the above-described multilayer pipe, a connection target member connected to the multilayer pipe, and an adhesive layer disposed between the multilayer pipe and the connection target member.

  Since the multilayer pipe connector according to the present invention has the above-described configuration, it has excellent adhesion reliability and weather resistance, has high flat strength, and can be used under pressure.

  When the multilayer pipe has a nominal diameter of 50A and the multilayer pipe is inserted into the connection target member at a load of 100 N, the insertion length of the multilayer pipe is defined by the insertion target length defined by the connection target member. (The insertion length of the multilayer tube / the insertion length defined by the connection target member) is preferably 1/3 or more, and more preferably 2/3 or less. When the ratio is equal to or more than the lower limit, the adhesive strength of the multilayer pipe connector can be further increased. When the ratio is equal to or less than the upper limit, a decrease in the long-term strength of the member to be connected due to excessive stress applied to the member to be connected can be suppressed.

  From the viewpoint of increasing the mechanical strength and the connection strength of the multilayer pipe connection over a long period of time, when a hot internal pressure creep test at 23 ° C. and a hoop stress of 6.4 MPa was performed on the multilayer pipe connection, It is preferable that the time until water leakage occurs is 100 hours or more from the start of the hot internal pressure creep test.

  From the viewpoint of increasing the mechanical strength and connection strength of the multilayer pipe connection over a long period of time, when the above-mentioned multilayer pipe connection was subjected to a hot internal pressure creep test at 40 ° C. and a hoop stress of 6.4 MPa, It is preferable that the time until water leakage occurs is 100 hours or more from the start of the hot internal pressure creep test.

  From the viewpoint of increasing the mechanical strength and connection strength of the multilayer pipe connection over a long period of time, when the above-mentioned multilayer pipe connection was subjected to a hot internal pressure creep test at 60 ° C. and a hoop stress of 6.4 MPa, It is preferable that the time until water leakage occurs is 100 hours or more from the start of the hot internal pressure creep test.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited only to the following examples.

  The following materials were prepared as materials for the multilayer tube.

Inner layer:
Polyvinyl chloride (PVC) (“TS-1000R” manufactured by Tokuyama Sekisui Industry Co., Ltd.)
Acrylic block copolymer (“LB550” manufactured by Kuraray)

Outer layer:
Resin material 1: A mixture of acrylonitrile-ethylene-propylene-styrene resin (AES resin) and ethylene propylene rubber (EPDM) ("UB-860" manufactured by A & L Japan, AES resin polymerization degree 600 to 1400, (AES resin content: 75% to 85% by weight, EPDM content: 15% to 25% by weight)

  Resin material 2: A mixture of acrylonitrile-ethylene-propylene-styrene resin (AES resin) and ethylene propylene rubber (EPDM) (“UB-700A” manufactured by A & L Japan, AES resin polymerization degree 600 to 1400, (AES resin content: 75% to 85% by weight, EPDM content: 15% to 25% by weight)

  Resin material 3: Acrylonitrile-styrene resin (AS resin) (“100PCF” manufactured by A & L Japan Co., Ltd., degree of polymerization of AS resin 600 to 1400)

  Resin material 4: A mixture of acrylonitrile-ethylene-propylene-styrene resin (AES resin), acrylonitrile-styrene-acrylate resin (ASA resin), ethylene propylene rubber (EPDM), and acrylic rubber (“MW266” manufactured by Techno Polymer, AES Degree of polymerization of resin and ASA resin 600 to 1400, total content of AES resin and ASA resin in resin material 75% to 85% by weight, total content of EPDM and acrylic rubber 15% to 25% by weight %)

  Resin material 5: Mixture of polymethyl methacrylate (PMMA) and acrylic rubber (“IRH50” manufactured by Mitsubishi Rayon Co., Ltd., degree of polymerization of PMMA 800 to 1200, content of PMMA in resin material 50% by weight to 70% by weight, (Acrylic rubber content: 30% by weight to 50% by weight)

  Resin material 6: polymethyl methacrylate (PMMA) (“VH” manufactured by Mitsubishi Rayon Co., polymerization degree 800 to 1200)

  Resin material 7: polymethyl methacrylate (PMMA) ("MF" manufactured by Mitsubishi Rayon Co., polymerization degree 200 to 400)

  Resin material 8: Acrylic block copolymer (“LB550” manufactured by Kuraray)

  Resin material 9: Mixture of polymethyl methacrylate (PMMA) and butadiene rubber (“VRS40” manufactured by Mitsubishi Rayon Co., Ltd., degree of polymerization of PMMA 400 to 600, PMMA content in resin material 50% by weight to 70% by weight, butadiene (Rubber content: 30% by weight to 50% by weight)

  Resin material 10: Mixture of polymethyl methacrylate (PMMA) and butadiene rubber (“IRS204” manufactured by Mitsubishi Rayon Co., Ltd., degree of polymerization of PMMA 200 to 400, PMMA content in resin material 50% by weight to 70% by weight, butadiene (Rubber content: 30% by weight to 50% by weight)

  Resin material 11: A mixture of polymethyl methacrylate (PMMA) and an adipic acid-based polyester plasticizer ("D620" manufactured by Mitsubishi Chemical Corporation) (degree of polymerization of PMMA 800 to 1200, content of PMMA in resin material 80% by weight) , Adipic acid-based polyester plasticizer content 20% by weight)

  Pigment 1: A mixture containing 70% by weight of titanium oxide, 15% by weight of a dispersant, 10% by weight of a composite oxide of titanium, antimony and chromium, and 5% by weight of a composite oxide of zinc, iron and chromium.

  Pigment 2: A mixture containing 70% by weight of titanium oxide, 15% by weight of a dispersant, 10% by weight of a composite oxide of titanium, antimony and chromium, and 5% by weight of a composite oxide of zinc, iron and chromium.

  Pigment 3: A mixture containing 70% by weight of titanium oxide, 15% by weight of a dispersant, 10% by weight of a composite oxide of titanium, antimony and chromium, and 5% by weight of a composite oxide of zinc, iron and chromium.

  In addition, the pigments 1 to 3 are pigments that are distributed so that the average particle diameters are different as described later.

Adhesive material:
Ethlon adhesive (“No.100S” manufactured by Sekisui Chemical Co., Ltd., vinyl chloride adhesive)
The solvent for the Eslon adhesive used was a mixture of 20% by weight of methyl ethyl ketone, 40% by weight of tetrahydrofuran, and 40% by weight of cyclohexanone. The used Eslon adhesive contains a chlorinated vinyl chloride resin as a solute.

  The following materials were prepared as members to be connected.

  TS socket (“TS50” manufactured by Sekisui Chemical Co., Ltd., material: polyvinyl chloride)

(Example 1)
(1) Production of Multilayer Pipe In the configuration shown in Table 1 below, a multilayer pipe was molded under the following extrusion conditions. A tubular body in which the outer surface of the inner layer was covered with the outer layer was obtained. The nominal diameter of the obtained multilayer tube was 50 A, the outer diameter was 60 mm, the thickness of the inner layer was 4.1 mm, and the thickness of the outer layer was 0.1 mm. The obtained tubular body was used as a straight tube of 40 cm to produce a multilayer tube.

[Extrusion conditions]
Extruder: "SLM60" manufactured by Nagata Seisakusho Co., Ltd. (Two-axis different direction parallel extruder)
Sub-extruder: "OPE-40" manufactured by Nagata Seisakusho (single screw extruder)
Mold: Pipe mold, for making multi-layer pipe for nominal diameter 50A Total extrusion rate: 100kg / h
Resin temperature: Multilayer tube main body (inner layer) 190 ° C (temperature at mold entrance), coating layer (outer layer) 220 ° C (temperature at mold entrance)

(2) Preparation of piping (multilayer pipe connector) After confirming that the insertion length of the multilayer pipe at a load of 100 N into the member to be connected is 21 mm or more and 42 mm or less, piping (multilayer pipe connector) is performed. ) Was prepared.

  Two multilayer tubes were prepared, and 4 g of an adhesive material (Ethlon adhesive) was applied to the outer surface of the outer layer of each multilayer tube from one end of the multilayer tube to a position 63 mm in the axial direction of the multilayer tube. Further, 4 g of an adhesive material (Eslon adhesive) was applied to the inner surfaces of both ends of the connection target member (TS socket). The multi-layer tube was inserted into both ends of the member to be connected, and was fixed so that it would not come back for 30 seconds. In this way, a pipe was prepared in which the multilayer pipe, the connection target member, and the multilayer pipe were provided in this order.

(Examples 2 to 12 and Comparative Examples 1 to 4)
A pipe was produced in the same manner as in Example 1 except that the configuration of the multilayer pipe was changed as shown in Tables 1 to 3.

(Evaluation)
(1) Average particle size of pigment An outer layer was cut out from the obtained multilayer tube, dissolved in 0.1 mol / L of tetrohydrofuran, and the pigment was separated and dried. The obtained pigment was subjected to laser diffraction type particle size distribution measurement using a laser diffraction type particle size distribution analyzer (“SALD-2200” manufactured by Shimadzu Corporation) to obtain a number average particle size.

  The average particle size of Pigment 1 was 50 nm, the average particle size of Pigment 2 was 200 nm, and the average particle size of Pigment 3 was 1000 nm.

(2) Yield strength (23 ° C, 40 ° C and 60 ° C)
Only the outer layer was cut out from the connection portion of the obtained pipe, and roll press processing was performed under the following roll press conditions to obtain a dumbbell-shaped sample. The length direction of the sample was aligned with the axial direction of the multilayer tube. Specifically, the dumbbell shape of the sample was the shape of a test piece according to JIS K7161-1. The obtained sample was immersed in a solvent for the adhesive material (a mixed solution containing 20% by weight of methyl ethyl ketone, 40% by weight of tetrahydrofuran, and 40% by weight of cyclohexanone) at 23 ° C. for 30 minutes. Next, the immersed sample was dried at 60 ° C. for 72 hours. Next, the dried sample was subjected to a tensile test at 23 ° C., 40 ° C. or 60 ° C., and a tensile speed of 5 mm / min in accordance with JIS K7161-1. From the obtained test results, the yield strength (maximum yield strength) was calculated. As a tensile tester, "Tabletop precision universal tester AGS-X" manufactured by Shimadzu Corporation was used. When the dried sample broke before yielding, the pressure at the time of breaking was defined as the yield strength.

[Roll press conditions]
Heating temperature: 195 ° C
Heating time: 3 minutes Preheating temperature: 195 ° C
Preheating time: 3 minutes Press pressure: 20 MPa
Press time: 3 minutes

(3) Adhesive strength (23 ° C, 40 ° C and 60 ° C) (short term connection reliability)
Only the outer layer was cut out of the obtained multilayer pipe, and roll-pressed under the roll-press conditions determined in the above (2) Evaluation of yield strength, and a first test of 2.5 cm × 7.5 cm × 3.00 mm was performed. I got a piece. The member to be connected was cut out and roll-pressed under the roll-press conditions determined in the above (2) Evaluation of yield strength to obtain a second test piece of 2.5 cm × 7.5 cm × 3.00 mm. 0.1 g of Eslon adhesive is applied to the surface of the obtained first test piece, and the second test piece is superimposed on the applied portion and adhered by applying a load of 0.2 N. After drying for 24 hours, a laminate was obtained. The bonding area between the first test piece and the second test piece was 300 mm ² . The obtained laminate was subjected to a tensile test under the conditions of 23 ° C., 40 ° C. or 60 ° C., and a tensile speed of 5 mm / min. As a tensile tester, "Tabletop Precision Universal Tester AGX-X" manufactured by Shimadzu Corporation was used. The adhesive strength at 23 ° C., the adhesive strength at 40 ° C., and the adhesive strength at 60 ° C. were determined by the following equations. The adhesive strength at 23 ° C., the adhesive strength at 40 ° C., and the adhesive strength at 60 ° C. were determined according to the following criteria.

Adhesive strength (MPa) = Breaking load (N) / Adhesive area (mm ² )

[Judgment criteria for adhesive strength]
：: adhesive strength of 10 MPa or more ×: adhesive strength of less than 10 MPa

(4) Weight increase amount Only the outer layer was cut out from the obtained multilayer tube, and roll-pressed under the roll-pressing conditions evaluated in the above (2) Evaluation of yield strength to obtain a 2.5 cm × 5 cm × 1.00 mm. A sample was obtained. The weight of the obtained sample was measured. Next, the obtained sample is immersed in a solvent for the adhesive material (a mixed liquid containing 20% by weight of methyl ethyl ketone, 40% by weight of tetrahydrofuran, and 40% by weight of cyclohexanone) at 23 ° C. for 10 minutes, and then the immersed sample is immersed. Was weighed. Thereafter, the sample was dried at 23 ° C. for 24 hours, and the weight of the dried sample was measured. The weight increase was calculated by the following equation. The weight increase was determined based on the following criteria.

  Weight increase = (weight of sample after immersion-weight of sample after drying + weight of sample before immersion) / weight of sample before immersion

[Criteria for determining weight gain]
：: Weight increase of 1.25 times or more and less than 2 times Δ: Weight increase of more than 1.25 times and less than 1.25 times Δ △: Weight increase of more than 1.00 times and less than 1.25 times × : No change in weight increase

(5) Flatness A flatness test was carried out to compress the obtained multilayer pipe until the outer diameter of the multilayer pipe became 1/2 according to JIS K6741. As a testing machine, "Tabletop Precision Universal Testing Machine AGS-X" manufactured by Shimadzu Corporation was used. Flatness was determined based on the following criteria. The flattening rate is 50% when the outer diameter of the multilayer tube is reduced to 1/2 by the above compression, and the flattening ratio is 20% when the outer diameter of the multilayer tube is reduced to 4/5.

[Criteria for determining flatness]
：: No crack or crack occurs in the multilayer pipe even when compressed until the outer diameter of the pipe is reduced to 1/2 (no crack or crack occurs in the multilayer pipe at an aspect ratio of 50%)
C: Cracks or cracks occur in the multilayer pipe when the flatness is 20% or more and less than 50%. X: Cracks or cracks occur in the multilayer pipe when the flatness is less than 20%.

(6) Hot internal pressure creep test (23 ° C, 40 ° C and 60 ° C) (long-term connection reliability)
The obtained pipe (multilayer pipe connector) was allowed to stand at 60 ° C. for 168 hours. After standing, a water pressure of 1.0 MPa (hoop stress: 6.4 MPa) was applied to the pipe at 23 ° C., 40 ° C., or 60 ° C., and the time until water leakage occurred from the pipe was measured. A hot internal pressure creep test at 23 ° C., a hot internal pressure creep test at 40 ° C., and a hot internal pressure creep test at 60 ° C. were determined based on the following criteria.

[Criteria for hot internal pressure creep test]
：: The time from the start of the hot internal pressure creep test to the breakage of the pipe and the occurrence of water leakage is 100 hours or more. Δ: The time from the start of the hot internal pressure creep test to the breakage of the pipe and the occurrence of water leak is 50 hours. Time or more and less than 100 hours ×: Less than 50 hours from the start of the hot internal pressure creep test to the breakage of the pipe and the occurrence of water leakage

(7) Total light transmittance Only the outer layer of the obtained multilayer tube was cut out and roll-pressed under the roll-pressing conditions used in the above (2) Evaluation of yield strength to obtain a thickness of 0.20 mm, 0.25 mm, and 0.2 mm. Samples of 30 mm, 0.35 mm, 0.40 mm, and 0.50 mm were prepared. Since the thickness of each of the obtained samples fluctuated ± 0.02 mm, an accurate thickness was measured with a micrometer. The total light transmittance of the obtained sample was measured according to JIS K7361-1 using "NDH2000" manufactured by Nippon Denshoku Industries Co., Ltd. The thickness of the sample was plotted on the abscissa and the total light transmittance was plotted on the ordinate on the semilogarithmic graph. According to the following formula, the total light transmittance of the outer layer per 0.1 mm thickness and the total light transmittance in the thickness direction of the outer layer (the outer layer having the same thickness as the outer layer in the obtained multilayer tube) were calculated. The total light transmittance was determined based on the following criteria.

Total light transmittance (%) per 0.1 mm thickness of outer layer = 100 × exp (−A × 0.1)
Total light transmittance (%) in the thickness direction of the outer layer = 100 × exp (−A × T)
T: thickness of outer layer (mm)

[Criteria for total light transmittance]
：: The total light transmittance per 0.1 mm thickness of the outer layer or the total light transmittance in the thickness direction of the outer layer is 30% or less △: The total light transmittance per 0.1 mm thickness of the outer layer and the outer layer which do not correspond to ○ Either one of the total light transmittance in the thickness direction exceeds 30% and not more than 50% Δ △: Does not correspond to △ and △, and the total light transmittance per 0.1 mm thickness of the outer layer and the total thickness in the thickness direction of the outer layer Either one of the light transmittances is more than 50% and not more than 85% ×: The total light transmittance per 0.1 mm of the thickness of the outer layer and the total light transmittance in the thickness direction of the outer layer exceed 85%.

(8) 50% Impact Fracture Height A drop weight test (impact resistance test) was performed on the obtained multilayer pipe at 0 ° C. using a 3 kg weight in accordance with Annex JA of JIS K6741. Next, the 50% impact fracture height was calculated according to JIS K7211. "FALLING DART IMPACT TESTER" manufactured by Yasuda Seiki Seisaku-Sho, Ltd. was used as a falling weight tester. However, the length of the test piece was 3 cm. The 50% impact fracture height was determined according to the following criteria.

[Criteria for 50% impact fracture height]
：: 50% impact breaking height is 150 cm or more △: 50% impact breaking height is 100 cm or more and less than 150 cm △△: 50% impact breaking height is more than 20 cm and less than 100 cm ×: 50% impact breaking height is 20 cm or less

(9) Weather resistance test The obtained multilayer pipe was subjected to a weather resistance test for 800 hours under the following conditions. As a weather resistance tester, "METALWEATHER" manufactured by Daipla Wintes was used.

[Weather resistance test conditions]
Operation mode: L + D
L: Irradiation intensity 75 mW / cm ² , black panel temperature 50 ° C, humidity 50%, 4 hours D: No irradiation, black panel temperature 30 ° C, humidity 98%, 4 hours Shower: 30 seconds before and after D each

(10) Retention of Impact Strength The 50% impact fracture height of the multilayer pipe after the weather resistance test was determined in the same manner as in the above (8) Evaluation of 50% impact fracture height. From the above (8) the 50% impact fracture height in the multilayer pipe before the weather resistance test obtained by the 50% impact fracture height and (9) the 50% impact fracture height in the multilayer pipe after the weather resistance test was performed, The strength retention was determined by the following equation. The impact strength retention was determined based on the following criteria.

  Impact strength retention (%) = (50% impact fracture height after weathering test / 50% impact fracture height before weathering test) × 100

[Judgment criteria for impact strength retention]
：: The impact strength retention is 80% or more △: The impact strength retention is 50% or more and less than 80% △△: The impact strength retention is 30% or more and less than 50% ×: The impact strength retention is 30% Less than

(11) Color difference L, a, and b values of the obtained multilayer tube were measured using a color difference meter “NR-300” manufactured by Nippon Denshoku Industries Co., Ltd. based on JIS-Z8730. In addition, L, a, and b were measured in the same manner also for the multilayer pipe subjected to the above (9) weather resistance test. The color difference before and after the weather resistance test was determined by the following equation. The color difference was determined based on the following criteria.

ΔE = [(ΔL) ² + (Δa) ² + (Δb) ² ] ^1/2

[Criteria for determining color difference]
：: ΔE is 5 or less Δ: ΔE is more than 5 and 10 or less Δ △: ΔE is more than 10 and 15 or less ×: ΔE is more than 15

(12) Comprehensive Judgment Points were calculated in each example and each comparative example from the judgment results of each evaluation item.

(3) Adhesion strength judgment: ○: 10 points, ×: 0 points (4) Weight increase judgment: ：: 10 points, Δ: 5 points, Δ: 1 point, ×: 0 points (5) Flatness Evaluation of strength: ５: 5 points, Δ: 3 points, ×: 0 point (6) Evaluation of hot internal pressure creep test: ：: 10 points, Δ: 5 points, ×: 0 point (7) Total light transmittance ○: 5 points, △: 3 points, △△: 1 point, ×: 0 points (8) Judgment of 50% impact breaking height: ：: 5 points, Δ: 3 points, Δ: 1 point , ×: 0 points (10) Judgment of impact strength retention: ○: 10 points, Δ: 5 points, Δ: 1 point, ×: 0 points (11) Color difference judgment: ：: 10 points, Δ: 5 Points, Δ: 1 point, ×: 0 points

[Criteria for comprehensive judgment]
：: Total point is 95 points or more △: Total point is 51 points or more and 94 points or less ×: Total point is 50 points or less

  Tables 1 to 3 below show the configuration and results of the pipe (multilayer pipe connector).

DESCRIPTION OF SYMBOLS 1 ... Multilayer pipe 1a ... Terminal 11 ... Inner layer 12 ... Outer layer 21 ... Multilayer pipe connector 31 ... Connection target member 41 ... Adhesive layer

Claims (28)

A multilayer pipe used by connecting the connection target members,
With an inner layer and an outer layer,
The material of the inner layer includes a thermoplastic resin,
When the outer layer is immersed in a mixed solution containing 20% by weight of methyl ethyl ketone, 40% by weight of tetrahydrofuran, and 40% by weight of cyclohexanone at 23 ° C. for 30 minutes, and the immersed outer layer is dried at 60 ° C. for 72 hours. The yield strength at 23 ° C. of the outer layer after drying is 10 MPa or more;
A first test piece in which the material of the outer layer is formed, a second test piece in which polyvinyl chloride is formed, and a second test piece disposed between the first test piece and the second test piece; When a laminate having an adhesive layer formed of a vinyl-based adhesive material is obtained, the bond strength of the first test piece and the second test piece in the laminate at 23 ° C. is 10 MPa or more. There is a multilayer tube. The yield strength at 40 ° C. of the outer layer after the drying is 10 MPa or more,
2. The multilayer tube according to claim 1, wherein the adhesive strength between the first test piece and the second test piece in the laminate at 40 ° C. is 10 MPa or more. The yield strength at 60 ° C. of the outer layer after the drying is 10 MPa or more,
3. The multilayer tube according to claim 1, wherein an adhesive strength of the first test piece and the second test piece in the laminate at 60 ° C. is 10 MPa or more. 4.   The total light transmittance in the thickness direction of the outer layer is 50% or less, or the total light transmittance per 0.1 mm thickness of the outer layer is 50% or less. 2. The multilayer tube according to item 1. Nominal diameter is 50A,
The 50% impact fracture height is 100 cm or more when a 50% impact fracture height according to JIS K7211 is calculated after performing an impact resistance test according to JIS K6741 or JIS K6742. 5. The multilayer pipe according to any one of items 4 to 4.   When the weather resistance test is performed, an impact strength retention rate of the 50% impact fracture height after the weather resistance test is performed to the 50% impact fracture height before the weather resistance test is performed is 50% or more. The multilayer pipe according to claim 5.   The multilayer pipe according to any one of claims 1 to 6, wherein a color difference before and after the weather resistance test is 10 or less when the weather resistance test is performed.   The multilayer pipe according to any one of claims 1 to 7, wherein when performing a flattening test in which the outer diameter of the multilayer pipe is reduced to １ ／ in accordance with JIS K6741, no crack or crack occurs in the multilayer pipe. A multilayer tube as described. The material of the outer layer is a polymethyl methacrylate, acrylonitrile-styrene resin, acrylonitrile-styrene-acrylate resin, acrylonitrile-acrylic rubber-styrene resin, and acrylonitrile-ethylene-propylene-styrene resin. Including a plastic resin,
The multilayer pipe according to any one of claims 1 to 8, wherein the content of the weather-resistant thermoplastic resin is 50% by weight or more based on 100% by weight of the material of the outer layer.   The multilayer pipe according to claim 9, wherein the degree of polymerization of the weather-resistant thermoplastic resin is 500 or more and 2000 or less. The material of the outer layer includes at least one component of rubber, a thermoplastic elastomer, and a plasticizer,
The multilayer tube according to any one of claims 1 to 10, wherein the content of the component is 5% by weight or more and 50% by weight or less in 100% by weight of the material of the outer layer. The material of the outer layer contains an inorganic pigment,
The multilayer tube according to any one of claims 1 to 11, wherein the inorganic pigment has an average particle size of 100 nm or more and 800 nm or less. A multilayer pipe comprising an inner layer and an outer layer,
A connection target member connected to the multilayer pipe,
An adhesive layer disposed between the multilayer tube and the connection target member,
The material of the inner layer in the multilayer tube includes a thermoplastic resin,
After immersing the outer layer in the multilayer tube in a solvent of the material for the adhesive layer at 23 ° C. for 30 minutes, and drying the immersed outer layer at 60 ° C. for 72 hours, the outer layer after drying is dried at 23 ° C. The yield strength at 10 MPa or more,
A multilayer pipe connector having an adhesion strength between the multilayer pipe and the member to be connected at 23 ° C. of 10 MPa or more. The yield strength at 40 ° C. of the outer layer after the drying is 10 MPa or more,
The multilayer pipe connector according to claim 13, wherein an adhesive strength between the multilayer pipe and the connection target member at 40 ° C is 10 MPa or more. The yield strength at 60 ° C. of the outer layer after the drying is 10 MPa or more,
The multilayer pipe connector according to claim 13 or 14, wherein the adhesive strength between the multilayer pipe and the connection target member at 60 ° C is 10 MPa or more. The solvent in the material of the adhesive layer is calculated by the following equation (1) when the outer layer of the multilayer tube is immersed in the solvent at 23 ° C. for 10 minutes and then the immersed outer layer is dried. The multilayer pipe connector according to any one of claims 13 to 15, which is a solvent that increases the weight by 1.25 times or more.
Weight increase = (weight of outer layer after immersion−weight of outer layer after drying + weight of outer layer before immersion) / weight of outer layer before immersion (1)   17. The hot internal pressure creep test at 23 ° C. and a hoop stress of 6.4 MPa, the time until water leakage occurs is 100 hours or more from the start of the hot internal pressure creep test. 18. A multilayer pipe connector according to any one of the preceding claims.   18. The hot internal pressure creep test at 40 ° C. and a hoop stress of 6.4 MPa, the time until water leakage occurs is 100 hours or more from the start of the hot internal pressure creep test. A multilayer pipe connector according to any one of the preceding claims.   19. The hot internal pressure creep test at 60 ° C. and a hoop stress of 6.4 MPa, the time until water leakage occurs is 100 hours or more from the start of the hot internal pressure creep test. A multilayer pipe connector according to any one of the preceding claims.   The total light transmittance in the thickness direction of the outer layer in the multilayer tube is 50% or less, or the total light transmittance per 0.1 mm thickness of the outer layer in the multilayer tube is 50% or less. 20. The multilayer pipe connector according to any one of 13 to 19, The nominal diameter of the multilayer tube is 50A,
After performing an impact resistance test according to JIS K6741 or JIS K6742 on the multilayer pipe, when calculating a 50% impact breaking height according to JIS K7211, the 50% impact breaking height is 100 cm or more. The multilayer pipe connector according to any one of claims 13 to 20.   When the weather resistance test was performed on the multilayer pipe, the 50% impact fracture height after the weather resistance test was performed and the impact strength retention rate with respect to the 50% impact fracture height before the weather resistance test was performed was 50%. The multilayer pipe connector according to claim 21, which is as described above.   The multilayer pipe connector according to any one of claims 13 to 22, wherein a color difference before and after the weather resistance test is 10 or less when the weather resistance test is performed on the multilayer pipe.   24. The multilayer pipe according to claims 13 to 23, wherein when performing a flattening test of compressing the multilayer pipe until the outer diameter of the multilayer pipe is reduced to １ ／ in accordance with JIS K6741, the multilayer pipe does not crack or crack. A multilayer pipe connector according to any one of the preceding claims. The material of the outer layer in the multilayer tube is at least one of polymethyl methacrylate, acrylonitrile-styrene resin, acrylonitrile-styrene-acrylate resin, acrylonitrile-acrylic rubber-styrene resin, and acrylonitrile-ethylene-propylene-styrene resin. Containing a weather-resistant thermoplastic resin,
The multilayer pipe connector according to any one of claims 13 to 24, wherein the content of the weather-resistant thermoplastic resin is 50% by weight or more based on 100% by weight of the material of the outer layer in the multilayer pipe.   The multilayer pipe connector according to claim 25, wherein the degree of polymerization of the weather-resistant thermoplastic resin is 500 or more and 2000 or less. The material of the outer layer in the multilayer tube includes at least one component of rubber, a thermoplastic elastomer, and a plasticizer,
The multilayer pipe connector according to any one of claims 13 to 26, wherein, in 100% by weight of the material of the outer layer in the multilayer pipe, the content of the component is 5% by weight or more and 50% by weight or less. The material of the outer layer in the multilayer tube contains an inorganic pigment,
The multilayer pipe connector according to any one of claims 13 to 27, wherein the average particle size of the inorganic pigment is 100 nm or more and 800 nm or less.

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