JP2019095050A - Multilayer pipe and multilayer pipe connection body - Google Patents

Abstract

To provide a multilayer pipe having excellent adhesion reliability and high flat strength, and capable of being used under a pressure.SOLUTION: A multilayer pipe includes an inner layer and an outer layer. The inner layer has the tubular shape, and the outer layer is disposed on an outer surface of the inner layer. A tensile strength at 23°C of the inner layer measured in accordance with JIS K6815-2 or JIS K7161-2 is 25 MPa or more and 67 MPa or less, a tensile elongation at 23°C of the inner layer measured in accordance with JIS K6815-2 or JIS K7161-2 is 10% or more, a tensile strength at 23°C of the outer layer measured in accordance with JIS K6815-2 or JIS K7161-2 is 25 MPa or more and 67 MPa or less, and a tensile elongation at 23°C of the outer layer measured in accordance with JIS K6815-2 or JIS K7161-2 is 10% or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a multilayer tube comprising an inner layer and an outer layer. The present invention also relates to a multilayer pipe connector using the above multilayer pipe.

  Many buildings, such as apartments, apartments and detached houses, use plastic piping to supply water and drain water. Moreover, when using piping outdoors or when it is necessary to prevent permeation of oxygen in piping, piping in which the inner layer and the outer layer formed of the highly functional resin composition are integrated is used. ing. For example, in "color pipe" manufactured by Sekisui Chemical Co., Ltd., the inner layer is a vinyl chloride resin (PVC resin), and the outer layer is a resin excellent in weather resistance, which enables outdoor use.

  Moreover, 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 joints. At this time, an adhesive layer may be formed by an adhesive at the end of the pipe, and the pipe may be connected by the adhesive layer.

  Patent Document 1 below discloses a vinyl chloride resin pipe in which the outer periphery of the pipe body is coated with an outer layer. The pipe main 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.

JP 2002-254576 A

  In the conventional piping as described in Patent Document 1, the plastic pipes are connected to each other through the adhesive layer disposed on the outer surface of the outer layer covering the piping main body. In the conventional piping, the first and second plastic pipes are connected to each other by bonding the outer surface of the first plastic pipe and the inner surface of the second plastic pipe through the adhesive layer. In conventional piping, the adhesion between the outer layer and the connection target member is poor, and sufficient adhesion reliability may not be obtained. In particular, when the material of the first plastic pipe and the material of the second plastic pipe are different, it is difficult to obtain sufficient adhesion reliability. As a result, when the internal pressure rises due to water flow or the like, the connected piping may come off. The above-mentioned adhesion reliability means both the adhesion strength (short-term connection reliability) and the creep strength (long-term connection reliability) of the multilayer pipe connector.

  Moreover, in the conventional piping as described in Patent Document 1, when the piping is deformed by an external pressure or the like, the piping may be damaged, or the outer layer may be cracked or broken.

  The object of the present invention is to provide a multilayer tube which has excellent adhesion reliability and high flat strength and can be used under pressure. Another object of the present invention is to provide a multilayer pipe connection using the above-described multilayer pipe.

  According to a broad aspect of the invention, an inner layer and an outer layer are provided, said inner layer being tubular, said outer layer being arranged on the outer surface of said inner layer, JIS K6815-2 or JIS K7161-2. The tensile strength at 23 ° C. of the inner layer measured in accordance with the above is 25 MPa or more and 67 MPa or less, and the tensile strength at 23 ° C. of the inner layer measured in accordance with JIS K6815-2 or JIS K7161-2 The elongation of the outer layer is 10% or more, and the tensile strength at 23 ° C. of the outer layer measured according to JIS K6815-2 or JIS K7161-2 is 25 MPa or more and 67 MPa or less, and JIS K6815-2 or JIS A multilayer pipe is provided in which the tensile elongation at 23 ° C. of the outer layer measured according to K7161-2 is 10% or more.

  In a specific aspect of the multilayer tube according to the present invention, when the outer layer is immersed in the adhesive for 30 minutes and then the outer layer after immersion is dried at 60 ° C. for 48 hours, JIS K6815-2 or JIS K7161-2 The tensile strength at 40 ° C. of the outer layer after drying measured in accordance with the above is 10 MPa or more.

  In a particular aspect of the multilayer tube according to the present invention, the material of the outer layer comprises a soft thermoplastic resin.

  In a specific aspect of the multilayer tube according to the present invention, the soft thermoplastic resin is a rubber having a structural unit derived from butyl rubber, ethylene propylene rubber, urethane rubber, silicone rubber, acrylic rubber, fluoro rubber, or diene skeleton. is there.

  In a specific aspect of the multilayer tube according to the present invention, the content of the soft thermoplastic resin is 5% by weight or more and 70% by weight or less in 100% by weight of the material of the outer layer.

  In one particular aspect of the multilayer tube according to the present invention, the material of the outer layer further comprises at least one component of a thermoplastic elastomer and a plasticizer.

  In a specific aspect of the multilayer tube according to the present invention, the total content of the soft thermoplastic resin and the component is 5% by weight or more and 70% by weight or less in 100% by weight of the material of the outer layer.

  In one particular aspect of the multilayer tube according to the present invention, the material of the outer layer further comprises a weatherable thermoplastic resin.

  In a specific aspect of the multilayer tube according to the present invention, the content of the weatherable thermoplastic resin is 30% by weight or more in 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 weatherable thermoplastic resin is 400 or more and 2,500 or less.

  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 impact strength retention rate of the impact strength after the weathering test is 50% or more relative to the impact strength before the weathering test is 50%.

  According to a broad aspect of the present invention, there is provided a multilayer pipe comprising the above-mentioned multilayer pipe and a connection target member connected to the multilayer pipe, wherein an adhesive layer is disposed between the multilayer pipe and the connection target member. A connector is provided.

  In a particular aspect of the multilayer tube connector according to the present invention, the outer layer is immersed in the material of the adhesive layer for 30 minutes, and then the outer layer after immersion is dried at 60 ° C. for 48 hours as JIS K6815-2 Alternatively, the tensile strength at 40 ° C. of the dried outer layer measured in accordance with JIS K7161-2 is 10 MPa or more.

  In a specific aspect of the multilayer pipe connector according to the present invention, the absolute value of the difference between the SP value of the outer layer in the multilayer pipe and the SP value of the connection target member is 2.0 or less.

  In a specific aspect of the multilayer pipe connector according to the present invention, the adhesive strength between the multilayer pipe and the connection target member at 40 ° C. is 10 MPa or more.

  In a specific aspect of the multilayer pipe connector according to the present invention, the adhesive strength between the multilayer pipe and the connection target member at 60 ° C. is 10 MPa or more.

  In a specific aspect of the multilayer pipe joint according to the present invention, when a hot internal pressure creep test at 40 ° C. and a hoop stress of 6.4 MPa is performed, a time until a water leak occurs is the above-mentioned hot internal pressure It is more than 100 hours from the start of the creep test.

  In a particular aspect of the multilayer tube connector according to the present invention, when a hot internal pressure creep test at 60 ° C. and a hoop stress of 6.4 MPa is carried out, the time until water leakage occurs is It is more than 100 hours from the start of the creep test.

  The multilayer tube according to the present invention comprises an inner layer and an outer layer. In the multilayer tube according to the present invention, the inner layer is tubular, and the outer layer is disposed on the outer surface of the inner layer. In the multilayer pipe according to the present invention, the tensile strength at 23 ° C. of the above inner layer measured according to JIS K6815-2 or JIS K7161-2 is 25 MPa or more and 67 MPa or less, and JIS K6815-2 or JIS K7161 The tensile elongation at 23 ° C. of the above inner layer measured in accordance with −2 is 10% or more. In the multilayer pipe according to the present invention, the tensile strength at 23 ° C. of the outer layer measured according to JIS K6815-2 or JIS K7161-2 is 25 MPa or more and 67 MPa or less, and JIS K6815-2 or JIS K7161 The tensile elongation at 23 ° C. of the above outer layer measured according to -2 is 10% or more. Since the multilayer tube according to the present invention has the above-mentioned configuration, it has excellent adhesion reliability, high flat strength, and can be used under pressure.

FIG. 1 is a cross-sectional view showing a multilayer tube according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an example of a multilayer pipe connection using a multilayer pipe according to an embodiment of the present invention.

  Hereinafter, the present invention will be described in detail.

(Multilayer pipe)
The multi-layer pipe according to the present invention is preferably used by connecting connection target members. The multilayer tube according to the present invention comprises an inner layer and an outer layer. In the multilayer tube according to the present invention, the inner layer is tubular, and the outer layer is disposed on the outer surface of the inner layer. The inner layer is a layer located inside the outer layer, and is a tube 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, a three-layer structure, or a three or more-layer structure. The outer layer is preferably the outermost layer (the 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. Moreover, it is preferable that the said outer layer is a layer which has a weather resistance.

  In the multilayer pipe according to the present invention, the tensile strength at 23 ° C. of the above inner layer measured according to JIS K6815-2 or JIS K7161-2 is 25 MPa or more and 67 MPa or less, and JIS K6815-2 or JIS K7161 The tensile elongation at 23 ° C. of the above inner layer measured in accordance with −2 is 10% or more. In the multilayer pipe according to the present invention, the tensile strength at 23 ° C. of the outer layer measured according to JIS K6815-2 or JIS K7161-2 is 25 MPa or more and 67 MPa or less, and JIS K6815-2 or JIS K7161 The tensile elongation at 23 ° C. of the above outer layer measured according to -2 is 10% or more.

  Since the multilayer tube according to the present invention is provided with the above-mentioned configuration, it has excellent adhesion reliability, high flat strength, and can be used under pressure.

  Moreover, in the multilayer pipe according to the present invention, since the above configuration is provided, the weather resistance of the multilayer pipe can be improved. Therefore, even when the multilayer pipe is used outdoors, the mechanical strength of the multilayer pipe can be maintained high, and excellent adhesion reliability can be maintained.

  In the multilayer pipe according to the present invention, since the above configuration is provided, sufficient connectivity between the multilayer pipe and the connection target member is sufficient when the multilayer pipe connection body in which the multilayer pipe and the connection target member are connected is manufactured. Thus, the axial connectivity of the multilayer tube connector of the multilayer tube can be sufficiently enhanced. Further, even if the diameter of the multilayer pipe is increased, deformation due to the weight of the multilayer pipe can be suppressed, and the connection reliability between the multilayer pipe and the connection target member can be sufficiently improved.

  The multilayer tube according to the present invention is provided with the above-described configuration, so even if pressure is applied by water supply or the like in the multilayer tube connector, or pressure due to shock or the like is applied from outside the multilayer tube connector, It is difficult for detachment of the multilayer pipe and the connection target member to occur, and the multilayer pipe connector can be used in a state where the multilayer pipe and the connection target member are connected.

  In the multilayer pipe according to the present invention, since the above-described configuration is provided, the weather resistance of the multilayer pipe connector is improved when the multilayer pipe connector in which the multilayer pipe and the connection target member are connected is manufactured. Can. Therefore, even when the multilayer pipe connector is used outdoors, the mechanical strength of the multilayer pipe connector can be maintained high, and excellent adhesion reliability can be maintained.

  In the present invention, the connection target member means a member connected to a multilayer pipe and used. In the present invention, the connection target member includes, for example, a joint for connecting the first pipe (first multilayer pipe) and the second pipe (second multilayer pipe), and the first pipe (first pipe) The second pipe etc. which have a caliber different from the said 1st pipe directly connected with one multilayer pipe) are mentioned.

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

  FIG. 1 is a cross-sectional view showing a multilayer tube according to an embodiment of the present invention.

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

  The multilayer tube 1 comprises an inner layer 11 and an outer layer 12. The inner layer 11 is tubular. The inner layer 11 extends to both ends of the multilayer tube 1.

  The outer layer 12 is disposed on the outer surface of the inner layer 11. The outer layer 12 is disposed on the entire outer surface of the inner layer 11. The outer layer preferably extends to the opposite ends of the multilayer tube. The outer layer is preferably arranged in a tubular manner.

  Adhesive layer 13 is disposed on the outer surface of outer layer 12. The adhesive layer 13 is disposed on the outer surface of the outer layer 12 at the end of the multilayer tube 1. The adhesive layer 13 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 may 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 partial area of the outer surface of the outer layer. The adhesive layer does not have to be disposed at the end of the multilayer tube on the entire outer surface of the outer layer up to the end of the multilayer tube, even if it is disposed in a partial area of the end of the multilayer tube Good.

  In a multilayer pipe connector in which a multilayer pipe including an inner layer and an outer layer and a connection target member are bonded by a material (adhesive agent) of an adhesive layer, a multilayer pipe connector is formed by the inner layer, the outer layer, the adhesive layer, and the connection target member Is configured.

  When the weathering test shown below is carried out, the impact strength retention ratio of the impact strength after the weathering test to the impact strength before the weathering test is preferably 50% or more, more preferably 60% or more. More preferably, it is 80% or more. The mechanical properties of the multilayer tube can be maintained for a longer period of time as the above-described impact strength retention rate is at least the above lower limit.

  The weathering test is performed for 800 hours on condition of the following using "METALWEATHER" by Daipurintes company. In addition, the multilayer pipe after the said weather resistance test implementation is corresponded to the multilayer pipe after leaving it to stand outdoors 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 each before and after D

  The said impact strength can be calculated | required by conducting the impact resistance test based on JISK6741 or JIS K6742.

  The said impact strength retention can be calculated | required by the following formula.

  Impact strength retention (%) = (Impact strength after weathering test / Impact strength before weathering test) x 100

  In the multilayer tube, layers different from the inner layer, the outer layer and the adhesive layer may be disposed between the inner layer and the outer layer. The layers different from the inner layer, the outer layer and the adhesive layer are 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. It can be appropriately selected and combined according to the function.

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

  As said fiber reinforced resin layer, the layer etc. which combined the thermoplastic resin and the fiber for reinforcement are mentioned. The reinforcing fibers may be inorganic fibers or organic fibers. 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. In these reinforcing fibers, when the continuous fibers are arranged in the longitudinal direction, the continuous fibers arranged in the longitudinal direction and the continuous fibers intersecting or intersecting with the continuous fibers are arranged, and the fibers having a finite length It is used when arranged.

  From the viewpoint of further enhancing the connection reliability, the length of the adhesive layer in the axial direction of the multilayer tube is preferably 10 mm or more, more preferably 15 mm or more, still more preferably 20 mm or more, preferably 300 mm or less, more Preferably it is 250 mm or less, More preferably, it is 225 mm or less. In addition, when the said contact bonding layer is multiply arranged by the edge part of the both sides of a multilayer tube, etc., the said length means the length in one contact bonding layer.

  From the viewpoint of practical use, and from the viewpoint of improving the hydraulic characteristics and the 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 It is 400 mm or less.

  From the viewpoint of practical use, the thickness of the multilayer tube is preferably 2.2 mm or more, more preferably 2.5 mm or more, preferably 19 mm or less, more preferably 15 mm or less.

  The thickness of the outer layer is preferably 0.02 mm or more, more preferably 0.04 mm or more, preferably 0.50 mm or less, and more preferably from the viewpoint of practical use and the viewpoint of improving the weather resistance. It is 0.35 mm or less.

  The thickness of the inner layer is preferably 1.7 mm or more, more preferably 2.5 mm or more, preferably 19 mm or less, more preferably 15 mm or less from the viewpoint of practical use and the viewpoint of improving the weather resistance. It is.

  Hereinafter, other details of the multilayer pipe will be described.

(Inner layer)
In the multilayer tube according to the present invention, the tensile strength at 23 ° C. of the inner layer is 25 MPa or more and 67 MPa or less. If the tensile strength at 23 ° C. of the inner layer is less than 25 MPa, the multilayer pipe may be easily deformed, and the adhesiveness between the multilayer pipe and the connection target member may be lowered. In particular, when the diameter of the multilayer pipe is large, the weight of the multilayer pipe makes the multilayer pipe more likely to be deformed, and the connection reliability between the multilayer pipe and the connection target member may be further lowered.

  From the viewpoint of further enhancing the adhesion reliability, the tensile strength at 23 ° C. of the inner layer is preferably 30 MPa or more, more preferably 35 MPa or more, and preferably 63 MPa or less.

  In the multilayer tube according to the present invention, the tensile elongation at 23 ° C. of the inner layer is 10% or more. When the tensile elongation rate at 23 ° C. of the inner layer is less than 10%, the flat pipe strength is inferior, and the multilayer pipe joint may be broken when pressure is applied from outside the multilayer pipe connection due to impact or the like.

  From the viewpoint of further enhancing the flat strength, the tensile elongation at 23 ° C. of the above inner layer is preferably 12% or more, more preferably 15% or more.

  The tensile strength and tensile elongation at 23 ° C. of the inner layer are measured in accordance with JIS K6815-2 or JIS K7161-2. In addition, in the measurement of the said tensile strength and the said tensile elongation rate, JISK6815-2 and JISK7161-2 can be selected according to the shape of a test piece.

  The material of the inner layer is preferably a material whose tensile strength at 23 ° C. of the inner layer is 25 MPa or more and 67 MPa or less and whose tensile elongation at 23 ° C. of the inner layer is 10% or more. Examples of the material of the inner layer include polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), and polyvinylidene fluoride (PVDF). The material of the inner layer may be used alone or in combination of two or more.

  The polyvinyl chloride (PVC) is not particularly limited, and any conventionally known vinyl chloride resin may be used. Examples of the vinyl chloride resin include homopolymers of vinyl chloride monomers, copolymers of vinyl chloride monomers and monomers having an unsaturated bond that can be copolymerized with vinyl chloride monomers, and polymers and co-polymers other than vinyl chloride. Examples thereof include graft polymers in which vinyl chloride is graft-polymerized to a polymer. Only one type of vinyl chloride resin may be used, or two or more types may be used in combination.

  The monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer is not particularly limited, and α-olefin compounds such as ethylene, propylene and butylene; vinyl ester compounds such as vinyl acetate and vinyl propionate; butyl vinyl ether and cetyl Vinyl ether compounds such as vinyl ether; (meth) acrylic acid ester 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 N-substituted maleimide compounds, such as maleimide and N-cyclohexyl maleimide, etc. are mentioned. Only one type of monomer having an unsaturated bond copolymerizable with the above vinyl chloride monomer may be used, or two or more types may be used in combination.

  The polymer and copolymer for graft copolymerization of vinyl chloride are not particularly limited, and ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer, ethylene-ethyl acrylate copolymer, ethylene- Butyl acrylate-carbon monoxide copolymer, acrylonitrile-butadiene copolymer, polyurethane, chlorinated polyethylene, chlorinated polypropylene and the like can be mentioned. The polymer and copolymer which graft-copolymerize a vinyl chloride may be used only by 1 type, and 2 or more types may be used together.

  The polymerization degree of the vinyl chloride resin is preferably 100 or more, and preferably 10000 or less. When the degree of polymerization is at least the lower limit, long-term performance such as fatigue characteristics is unlikely to be impaired. When the degree of polymerization is less than or equal to the above upper limit, it is not necessary to use high 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.

  The vinyl chloride resin may be a post-chlorinated vinyl chloride resin.

(Outer layer)
In the multilayer tube according to the present invention, the tensile strength at 23 ° C. of the outer layer is 25 MPa or more and 67 MPa or less. If the tensile strength at 23 ° C. of the outer layer is less than 25 MPa, the multilayer pipe is likely to be deformed, and the multilayer pipe and the multilayer pipe joint may be broken.

  From the viewpoint of further enhancing the strength of the multilayer tube, the tensile strength at 23 ° C. of the outer layer is preferably 30 MPa or more, more preferably 35 MPa or more, preferably 65 MPa or less, more preferably 63 MPa or less.

  In the multilayer tube according to the present invention, the tensile elongation at 23 ° C. of the outer layer is 10% or more. When the tensile elongation rate at 23 ° C. of the outer layer is less than 10%, the flat pipe strength is inferior, and the multilayer pipe joint may be broken when a pressure due to impact or the like is applied from outside the multilayer pipe connection.

  From the viewpoint of further enhancing the flat strength, the tensile elongation at 23 ° C. of the outer layer is preferably 12% or more, more preferably 15% or more.

  The tensile strength at 23 ° C. and the tensile elongation of the outer layer are measured in accordance with JIS K6815-2 or JIS K7161-2. In addition, in the measurement of the said tensile strength and the said tensile elongation rate, JISK6815-2 and JISK7161-2 can be selected according to the shape of a test piece.

  The material of the outer layer is preferably a material having a tensile strength at 23 ° C. of 25 to 67 MPa and a tensile elongation of 10% or more at 23 ° C. of the outer layer.

  The multilayer tube including the inner layer and the outer layer and the connection target member are bonded using an adhesive. The adhesive layer is formed by the adhesive. The adhesive is a material of the adhesive layer.

  From the viewpoint of further enhancing the connection reliability, after the outer layer is immersed in the adhesive (the material of the adhesive layer) for 30 minutes, the outer layer after immersion is dried at 60 ° C. for 48 hours. The tensile strength at 40 ° C. of the outer layer is preferably 10 MPa or more.

  From the viewpoint of further enhancing the connection reliability, after the outer layer is immersed in the adhesive (the material of the adhesive layer) for 30 minutes, the outer layer after immersion is dried at 60 ° C. for 48 hours. The tensile strength at 60 ° C. of the outer layer is preferably 10 MPa or more.

  The tensile strength at 40 ° C. or 60 ° C. of the dried outer layer is measured in accordance with JIS K6815-2 or JIS K7161-2. In addition, in the measurement of the said tensile strength, JISK6815-2 and JISK7161-2 can be selected according to the shape of a test piece.

  From the viewpoint of improving both the tensile strength and the tensile elongation of the outer layer and further improving the adhesion reliability and the flat strength, it is preferable that the material of the outer layer contains a soft thermoplastic resin.

  Examples of the soft thermoplastic resin include dienes, butyl, ethylene propylene, urethanes, silicones, acrylics, and thermoplastic resins having a structural unit derived from fluorine. The above-mentioned soft thermoplastic resin may be used alone or in combination of two or more.

  As a thermoplastic resin which has a structural unit originating in the above-mentioned diene, butadiene rubber, nitrile rubber (NBR), etc. are mentioned.

  As a thermoplastic resin which has a structural unit derived from the said butyl, butyl rubber etc. are mentioned.

  As a thermoplastic resin which has a structural unit derived from the said ethylene propylene, ethylene propylene diene rubber etc. are mentioned.

  As a thermoplastic resin which has a structural unit derived from the above-mentioned acryl, acrylic rubber etc. are mentioned.

  As a thermoplastic resin which has a structural unit derived from the said silicone, silicone rubber etc. are mentioned.

  Examples of the thermoplastic resin having a structural unit derived from fluorine include fluororubber (FKM) and the like.

  From the viewpoint of further improving the flat strength, the soft thermoplastic resin is a rubber having a structural unit derived from a butyl rubber, an ethylene propylene rubber, a urethane rubber, a silicone rubber, an acrylic rubber, a fluoro rubber, or a diene skeleton. Is preferred.

  The content of the soft thermoplastic resin is preferably 5% by weight or more, more preferably 8% by weight or more, still more preferably 10% by weight or more, and preferably 70% by weight or less in 100% by weight of the material of the outer layer. More preferably, it is 60% by weight or less, still more preferably 55% by weight or less. Flat strength can be made still more favorable in the above-mentioned content being more than the above-mentioned lower limit and below the above-mentioned upper limit.

  From the viewpoint of making both the tensile strength and the tensile elongation of the outer layer better and making the flat strength even better, the material of the outer layer further comprises at least one of a thermoplastic elastomer and a plasticizer. It is preferable to include the following components (hereinafter sometimes referred to as component A in the present specification).

  The material of the outer layer preferably contains the soft thermoplastic resin and the component A.

  As the thermoplastic elastomer, α-olefin copolymer (EAO), styrene-butadiene copolymer (SB or SBS), styrene-ethylene butylene-styrene copolymer (SEBS), styrene-isoprene copolymer (SI or SIS), ethylene-alkyl acrylate Copolymer, ethylene-vinyl acetate (EVA), ethylene-acrylic acid copolymer (EAA), ionomer resin, elastomeric 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. Only one type of the thermoplastic elastomer may be used, or two or more types 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, EAA or EAA from the viewpoint of further improving the adhesion reliability and the flat 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.

  The content of the component A is preferably 5% by weight or more, more preferably 10% by weight or more, still more preferably 15% by weight or more, and preferably 70% by weight or less in 100% by weight of the material of the outer layer. Preferably it is 60 weight% or less, More preferably, it is 50 weight% or less. The adhesion reliability and the flat strength can be further improved when the content is at least the lower limit and the upper limit.

  The total content of the soft thermoplastic resin and the component A in 100% by weight of the material of the outer layer is preferably 5% by weight or more, more preferably 8% by weight or more, still more preferably 10% by weight or more Preferably it is 70 weight% or less, More preferably, it is 60 weight% or less, More preferably, it is 55 weight% or less. The adhesion reliability and the flat strength can be further improved when the content is at least the lower limit and the upper limit.

  From the viewpoint of practical use outdoors, it is preferable that the material of the outer layer further contains a weatherable thermoplastic resin.

  The material of the outer layer preferably includes the soft thermoplastic resin and the weatherable thermoplastic resin, and more preferably includes the soft thermoplastic resin, the component A, and the weatherable thermoplastic resin. The outer layer is preferably a layer having weatherability.

  As the above-mentioned weathering thermoplastic resin, polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), acrylonitrile-styrene resin (AS resin), acrylonitrile-butadiene-styrene resin (ABS resin), polyimide resin, acrylonitrile- Styrene-acrylate resin (ASA resin) etc. are mentioned. The above-mentioned weathering thermoplastic resin may be used alone or in combination of two or more.

  The degree of polymerization of the above-mentioned weathering thermoplastic resin is preferably 400 or more, more preferably 500 or more, preferably 2500 or less, more preferably 1800 or less, still more preferably 1500 or less. The adhesion reliability can be further enhanced when the degree of polymerization is at least the lower limit. When the degree of polymerization is less than or equal to the above upper limit, it is not necessary to use high temperature at the time of molding, and the processability is further improved.

  The content of the weatherable thermoplastic resin is preferably 30% by weight or more, more preferably 40% by weight or more, still more preferably 50% by weight or more, and preferably 100% by weight in 100% by weight of the material of the outer layer. The following content is more preferably 95 wt% or less, still more preferably 90 wt% or less. When the content is at least the lower limit and the upper limit, the weather resistance, the adhesion reliability, and the flat strength can be further improved.

  With regard to whether or not the resin has weatherability, when the color difference before and after the weathering test is 10 or less when the following weathering test is performed, it is judged that the resin has weatherability. The resin after the above-mentioned weathering test is carried out corresponds to the resin after being left outdoors for about 10 years.

  The weathering test is performed for 800 hours on condition of the following using "METALWEATHER" by Daipurintes company.

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 each before and after D

  The color difference is measured by using the color difference meter “NR-300” manufactured by Nippon Denshoku Kogyo Co., Ltd. to measure the L, a, b values of the resin before and after the weathering test based on JIS-Z8730, using the following formula Calculated ΔE.

ΔE = [(ΔL) ² + (Δa) ² + (Δb) ² ] ^1/2

  Preferably, 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. When the total light transmittance is 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 enhanced. 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 portion from the multilayer tube, and the material of the outer layer is molded to produce a layer having the same thickness as the thickness of the outer layer in the multilayer tube It 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.

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

  The total light transmittance is measured in accordance with JIS K7361-1.

  The outer layer may be used in combination with other materials as long as the effect of the present invention is not impaired. For example, in order to make the total light transmittance better, the material of the outer layer may contain a pigment and the like.

(Adhesive layer)
The adhesive layer is formed by an adhesive. The material of the adhesive layer is an adhesive. It does not specifically limit as a material (adhesive agent) of the said contact bonding layer, Sekisui Chemical Co., Ltd. make "Eslon adhesive agent No. 73S", "Eslon adhesive agent No. 100S", etc. are mentioned. The material of the adhesive layer (adhesive) may contain a solvent such as THF, methyl ethyl ketone, cyclohexanone, acetone, cyclohexane, ethyl acetate, and ethanol.

(Other details of multilayer tube)
If necessary, various additives may be used in the multilayer tube. As the above additives, stabilizers, stabilizing aids, lubricants, processing aids, impact modifiers, heat resistance improvers, antioxidants, ultraviolet absorbers, light stabilizers, fillers, pigments, plasticizers, etc. Can be mentioned. Only one type of the additive may be used, or two or more types may be used in combination.

  It does not specifically limit as said stabilizer, A heat stabilizer, a heat-stabilization adjuvant, etc. are mentioned. The heat stabilizers are not particularly limited, and examples thereof include organic tin stabilizers, lead stabilizers, calcium-zinc stabilizers, barium-zinc stabilizers, and barium-cadmium stabilizers. Examples of the organic tin-based stabilizer include dibutyltin mercapto, dioctyltin mercapto, dimethyltin mercapto, dibutyltin mercapto, dibutyltin maleate, dibutyltin maleate polymer, dioctyltin maleate, dioctyltin maleate polymer, dibutyltin laurate, and Dibutyltin laurate polymer etc. are mentioned. The heat stabilizers may be used alone or in combination of two or more.

  The heat stabilization aid is not particularly limited, and examples thereof include epoxidized soybean oil, phosphoric acid ester, polyol, hydrotalcite, and zeolite. The heat-stabilizing aid may be used alone or in combination of two or more.

  The lubricants include internal lubricants and external lubricants. The internal lubricant is used for the purpose of lowering the flow viscosity of the molten resin at the time of molding processing and preventing frictional heat generation. 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 paraffin wax, polyolefin wax, ester wax, montanic acid wax and the like can be mentioned. The lubricant may be used alone or in combination of two or more.

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

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

  The heat resistance improver is not particularly limited, and examples thereof include α-methylstyrene resins and N-phenylmaleimide resins. The heat resistance improver may be used alone or in combination of two or more.

  It does not specifically limit as said antioxidant, A phenol type antioxidant etc. are mentioned. As the above-mentioned antioxidant, only 1 type may be used and 2 or more types may be used together.

  The UV absorber is not particularly limited, and examples thereof include salicylic acid ester-based UV absorbers, benzophenone-based UV absorbers, benzotriazole-based UV absorbers, cyanoacrylate-based UV absorbers and the like. The ultraviolet absorbers may be used alone or in combination of two or more.

  It does not specifically limit as said light stabilizer, A hindered amine light stabilizer etc. are mentioned. The light stabilizers may be used alone or in combination of two or more.

  It does not specifically limit as said filler, Calcium carbonate, a talc, etc. are mentioned. Only one type of filler may be used, or two or more types may be used in combination.

  It does not specifically limit as said pigment, An organic pigment and an inorganic pigment are mentioned. Examples of the organic pigment include an azo organic pigment, a phthalocyanine organic pigment, a styrene organic pigment, and a dye lake organic pigment. Examples of the above-mentioned inorganic pigments include oxide-based inorganic pigments, molybdenum chromate-based inorganic pigments, sulfide / selenide-based inorganic pigments, and ferrocyanide-based inorganic pigments. Only one type of the pigment may be used, or two or more types may be used in combination.

  The above plasticizer may be added for the purpose of enhancing the processability at the time of molding. The above-mentioned plasticizer is not particularly limited, and dibutyl phthalate, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate and the like can be mentioned. Only one type of plasticizer may be used, or two or more types may be used in combination.

(Multilayer pipe connection)
A multilayer pipe connector according to the present invention comprises the above-described multilayer pipe and a connection target member connected to the multilayer pipe. In the multilayer pipe connector according to the present invention, the adhesive layer is disposed between the multilayer pipe including the inner layer and the outer layer and the connection target member. The connection target member 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), a pipe joint, and the like. As said pipe | tube, a single layer pipe | tube, a multilayer pipe | tube, etc. are mentioned.

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

  FIG. 2 is a cross-sectional view showing an example of a multilayer pipe connection using a multilayer pipe according to an embodiment of the present invention.

  The multilayer pipe connector 21 shown in FIG. 2 includes the multilayer pipe 1 and the connection target member 31. The multilayer pipe 1 is a multilayer pipe 1 shown in FIG. 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 13 disposed on the outer surface of the outer layer 12 at the end of the multilayer pipe 1.

  The adhesive layer in the multilayer pipe connector may be exposed from the end of the connection target member on the side of the multilayer pipe, or may not be exposed from the end of the connection target member on the side of the multilayer pipe.

  The material of the multilayer tube and the material of the inner surface of the connection target member may be the same or different. That is, the outer layer of the multilayer tube and the inner surface of the connection target member may be the same material or different materials. The fact that the outer layer of the multilayer tube and the inner surface of the connection target member are different means that the material composition of the material of the outer layer of the multilayer tube and the material of the inner surface of the connection target member are different. The material composition includes the molecular structure, molecular weight, and degree of polymerization of the components contained in the material.

  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 material of the connection target member may not include the material of the outer layer. From the viewpoint of enhancing the adhesive strength between the multilayer tube and the connection target member, the material of the connection target member preferably includes the material of the outer layer. The content of the material of the outer layer is preferably more than 0% by weight, preferably 100% by weight (total) or less, more preferably 90% by weight or less, still more preferably 80% by weight in 100% by weight of the material of the connection target member It is at most weight percent. If the content of the material of the outer layer contained in the material of the connection target member is less than the upper limit, the effects of the present invention are sufficiently exhibited, and the adhesion strength between the multilayer pipe and the connection target member is further enhanced be able to.

  When the multilayer pipe has a size of the nominal diameter 50A, when the multilayer pipe is inserted into the connection target member with a load of 100 N, the insertable length of the insertion length of the multilayer pipe defined by the connection target member The ratio to (the insertion length of the multilayer tube / the insertable length defined by the connection target member) is preferably 1/3 or more, and more preferably 2/3 or less. The adhesive strength of a multilayer tube connection body can be further improved as the said ratio is more than the said minimum. It can prevent that the long-term intensity | strength of a connection object member is impaired by the excessive stress being added to a connection object member that the said ratio is below the said upper limit.

  From the viewpoint of further enhancing the adhesive strength, the adhesive strength between the multilayer tube and the connection target member at 40 ° C. is preferably 10 MPa or more, more preferably 15 MPa or more.

  From the viewpoint of further enhancing the adhesive strength, the adhesive strength between the multilayer tube and the connection target member at 60 ° C. is preferably 10 MPa or more, more preferably 15 MPa or more.

  The adhesive strength between the multilayer tube and the connection target member at 40 ° C. and 60 ° C. is an indicator of short-term adhesion reliability.

  The adhesive strength at 40 ° C. and 60 ° C. between the multilayer tube and the connection target member can be measured as follows.

  A first test piece in which the material of the outer layer of the multilayer tube is molded, and a second test piece in which the material of the inner surface of the connection target member is molded are obtained. The material of the adhesive layer 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 superposed and bonded to obtain a laminate. In the obtained laminate, a layer adhered by the material of the adhesive layer is disposed between the first test piece and the second test piece. In addition, you may obtain the said laminated body by cutting out a multilayer pipe connection body.

  The obtained laminate is subjected to a tensile test at 40 ° C. or 60 ° C. and a tensile rate of 5 mm / min. The adhesive strength can be determined by the following equation from the breaking load when the laminate is broken and the bonding area of the first test piece and the second test piece. In addition, as a tensile testing machine, "table-type precision universal testing machine AGX-X" by Shimadzu Corp. can be used, for example.

Bonding strength (MPa) = breaking load (N) / bonding area (mm ² )

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

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

  The absolute value of the difference between the SP value of the outer layer of the multilayer pipe and the SP value of the inner surface of the connection target member is preferably from the viewpoint of further enhancing the connection reliability and enhancing the short-term and long-term adhesive strength. It is 2.0 or less, more preferably 1.0 or less. The SP value represents a measure of the affinity between substances and is also called the solubility parameter. It is known that the smaller the absolute value of the difference between the SP values, the higher the affinity.

  The above-mentioned SP value can be obtained from literature information, and can also be obtained by the calculation method of Hansen or Hoy, the estimation method of Fedors, or the like.

  Hereinafter, the present invention will be described in more detail by way of examples. The invention is not limited to the following examples.

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

Inner layer:
Polyvinyl chloride (PVC) (made by Tokuyama Sekisui Kogyo "TS-1000R")
Acrylic block copolymer (Kuraray's "LB550")

Outer layer:
Resin material 1: A mixture of acrylonitrile-ethylene-propylene-styrene resin (AES resin) and ethylene propylene rubber (EPDM) (Nippon A & L Co., Ltd. “UB-860”, polymerization degree of AES resin 600 to 1,400, among resin materials Content of weatherproof thermoplastic resin 75% by weight to 85% by weight, content of soft thermoplastic resin in resin material 15% by weight to 25% by weight)

  Resin material 2: A mixture of acrylonitrile-ethylene-propylene-styrene resin (AES resin) and ethylene propylene rubber (EPDM) (Nippon A & L Co., Ltd. “UB-700A”, polymerization degree of AES resin 600 to 1,400, among resin materials Content of weatherproof thermoplastic resin 75% by weight to 85% by weight, content of soft thermoplastic resin in resin material 15% by weight to 25% by weight)

  Resin material 3: Acrylonitrile-styrene resin (AS resin) ("100 PCF" manufactured by Nippon A & L Co., 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 ("MW 266" manufactured by Techno Polymer Co., Ltd., AES Degree of polymerization of resin and ASA resin 600 to 1,400, content of weatherable thermoplastic resin in resin material 75% to 85% by weight, content of soft thermoplastic resin in resin material 15% to 25% by weight)

  Resin material 5: Mixture of polymethyl methacrylate (PMMA) and acrylic rubber ("IRH 50" manufactured by Mitsubishi Rayon Co., polymerization degree of PMMA 800 to 1200, content of weatherable thermoplastic resin in resin material 50% by weight to 70% by weight, content of soft thermoplastic resin in resin material 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., Ltd., polymerization degree 200 to 400)

  Resin material 8: Acrylic block copolymer (manufactured by Kuraray "LB 550")

  Pigment ("Gray DCF-R2929-F" manufactured by Resino Color Corporation)

Adhesive layer:
Eslon adhesive (Sekisui Chemical Co., Ltd. "No. 100S", SP value 9.0)

  The following materials were prepared as connection target members.

  TS socket ("TS50" manufactured by Sekisui Chemical Co., Ltd., SP value 9.5)

Example 1
(1) Preparation of Multilayer Pipe In the configuration shown in Table 1 below, a multilayer pipe was formed under the following extrusion conditions. An outer surface of the inner layer was covered with the outer layer to obtain a tubular body. In addition, PVC was used as a material of an inner layer. Moreover, as a material of an outer layer, the mixed material of the resin material 1 and the pigment was used. The SP value of the outer layer was 10.0. The outer diameter of the obtained multilayer tube 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 resulting tubular body was used as a 40 cm straight pipe to produce a multilayer pipe.

[Extrusion conditions]
Extruder: "SLM 50" (made by Nagata Mfg. Co., Ltd.)
Sub-extruder: "OPH-40" (single-screw extruder) manufactured by Nagata Mfg. Co.
Mold: Mold for pipe, for producing multi-layer pipe for nominal diameter 50A Total extrusion amount: 20 kg / h
Resin temperature: Multilayer tube body (inner layer) 190 ° C (temperature at mold inlet), coating layer (outer layer) 220 ° C (temperature at mold inlet)

(2) Preparation of piping (multilayer pipe connection body) After confirming that the insertion length when inserting the multilayer pipe into the connection target member with a load of 100 N is 21 mm or more and 42 mm or less, the piping (multilayer pipe connection body ) Was produced.

  On the outer surface of the outer layer of the resulting multilayer tube, 4 g of the adhesive layer material (Eslon adhesive) was applied from one end of the multilayer tube to a position of 63 mm in the axial direction of the multilayer tube to prepare a multilayer tube comprising the adhesive layer . In the same manner, a total of two multilayer tubes provided with an adhesive layer were prepared. 4 g of each material (Eslon adhesive) of the adhesive layer was applied on the inner surfaces of both ends of the connection target member (TS socket). The multilayer tube provided with the obtained adhesive layer was inserted in the both ends of a connection object member (TS socket), and it fixed so that it did not return for 30 seconds. In this manner, a pipe including the multilayer pipe, the connection target member, and the multilayer pipe in this order was manufactured.

(Example 2)
A pipe was produced in the same manner as in Example 1 except that a mixed material of the resin material 5 and the pigment was used as the material of the outer layer, and the blending amount was changed as shown in Table 1. The SP value of the outer layer was 9.3.

(Example 3)
A pipe was produced in the same manner as in Example 1 except that a mixed material of resin material 2 and a pigment was used as the material of the outer layer, and the blending amount was changed as shown in Table 1. The SP value of the outer layer was 9.3.

(Example 4)
A pipe was produced in the same manner as in Example 1 except that a mixed material of the resin material 4 and the pigment was used as the material of the outer layer, and the blending amount was changed as shown in Table 1. The SP value of the outer layer was 9.5.

(Example 5)
The same procedure as in Example 1 was carried out except that a mixed material of resin material 5 and pigment was used as the material of the outer layer, the thickness of the outer layer was 0.2 mm, and the compounding amount was changed as shown in Table 1. The pipe was made. The SP value of the outer layer was 9.3.

(Comparative example 1)
A pipe was produced in the same manner as in Example 1 except that a mixed material of the resin material 6 and the pigment was used as the material of the outer layer, and the blending amount was changed as shown in Table 2. The SP value of the outer layer was 9.3.

(Comparative example 2)
A pipe was produced in the same manner as in Example 1 except that a mixed material of the resin material 7 and the pigment was used as the material of the outer layer, and the blending amount was changed as shown in Table 2. The SP value of the outer layer was 9.3.

(Comparative example 3)
A piping was produced in the same manner as in Example 1 except that a mixed material of resin material 3 and a pigment was used as the material of the outer layer, and the blending amount was changed as shown in Table 2. The SP value of the outer layer was 12.8.

(Comparative example 4)
Example 1 and Example 1 except that an acrylic block copolymer was used as the material of the inner layer, a mixed material of the resin material 8 and the pigment was used as the material of the outer layer, and the blending amount was changed as shown in Table 2. The piping was produced similarly. The SP value of the outer layer was 9.3.

(Evaluation)
(1) Outer layer strength 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 longitudinal direction of the sample coincided with the axial direction of the multilayer tube. Specifically, the dumbbell shape of the sample was the shape of the test piece in JIS K6815-2 or JIS K7161-2. The tensile test was implemented on the conditions of 23 degreeC and the tension rate of 5 mm / min based on JISK6815-2 or JIS K7161-2 using the obtained sample. From the test results obtained, the tensile strength and the tensile elongation were calculated, and were used as the outer layer strength (the tensile strength and the tensile elongation of the outer layer). As a tensile tester, a "table-type precision universal testing machine AGS-X" manufactured by Shimadzu Corporation was used.

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

(2) Inner layer strength From the connection part of the obtained piping, only the inner layer was cut out and roll press processing was performed under the same roll press conditions as the above (1) to obtain a dumbbell-shaped sample. The longitudinal direction of the sample coincided with the axial direction of the multilayer tube. Specifically, the dumbbell shape of the sample was the shape of the test piece in JIS K6815-2 or JIS K7161-2. The tensile test was implemented on the conditions of 23 degreeC and the tension rate of 5 mm / min based on JISK6815-2 or JIS K7161-2 using the obtained sample. From the test results obtained, the tensile strength and the tensile elongation were calculated to be the inner layer strength (the tensile strength and the tensile elongation of the inner layer). As a tensile tester, a "table-type precision universal testing machine AGS-X" manufactured by Shimadzu Corporation was used.

(3) Post-swelling strength From the connection portion of the obtained pipe, only the outer layer was cut out, and roll pressing was performed under the same roll pressing conditions as in (1) above to obtain a dumbbell-shaped sample. Specifically, the dumbbell shape of the sample was the shape of the test piece in JIS K6815-2 or JIS K7161-2. The obtained sample was immersed in the material of the adhesive layer (Eslon adhesive) for 30 minutes and then dried at 60 ° C. for 48 hours. A tensile test was performed on the dried sample according to JIS K6815-2 or JIS K7161-2 under the conditions of 40 ° C. or 60 ° C. and a tensile speed of 5 mm / min. From the test results obtained, the tensile strength was calculated and taken as the post-swelling strength. As a tensile tester, a "table-type precision universal testing machine AGS-X" manufactured by Shimadzu Corporation was used.

(4) Flat strength The obtained pipe was subjected to a flat test in accordance with JIS K6741. As a testing machine, "table type precision universal testing machine AGS-X" manufactured by Shimadzu Corporation was used. Flatness was determined according to the following criteria.

[Criteria for judging leveling strength]
:: Even if the flatness rate is 50%, breakage of the pipe or cracks or cracks do not occur in the outer layer. ×: If the flatness rate is less than 50%, the pipe breakage or cracks or cracks occur in the outer layer.

(5) Adhesive strength (40 ° C and 60 ° C) (short-term connection reliability)
From the obtained multilayer tube, only the outer layer is cut out, and roll press processing is performed under the roll press conditions performed in the above (1) evaluation of the outer layer strength, and a first test of 2.5 cm × 7.5 cm × 3.00 mm I got a piece. The connection target member was cut out, and roll press processing was performed under the roll press conditions performed in the evaluation of the (1) outer layer 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 first test piece obtained, the second test piece is superposed on the applied portion, and bonded with a load of 0.2 N at 23 ° C. It dried for 24 hours and obtained the laminated body. The adhesion area between the first test piece and the second test piece was 300 mm ² . The obtained laminate was subjected to a tensile test at 40 ° C. or 60 ° C. and a tensile rate of 5 mm / min. As a tensile testing machine, a "table-type precision universal testing machine AGX-X" manufactured by Shimadzu Corporation was used. The adhesive strength at 40 ° C. and the adhesive strength at 60 ° C. were determined by the following formulas. The adhesive strength at 40 ° C. and the adhesive strength at 60 ° C. were determined based on the following criteria.

Bonding strength (MPa) = breaking load (N) / bonding area (mm ² )

[Criteria for adhesion strength (40 ° C and 60 ° C)]
○: adhesive strength is 10 MPa or more Δ: adhesive strength is 5 MPa or more and less than 10 MPa ×: adhesive strength is less than 5 MPa

(6) Hot internal pressure creep test (40 ° C and 60 ° C) (long-term connection reliability)
The obtained pipe (multilayer pipe connection) 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 loaded at 40 ° C. or 60 ° C. into the pipe, and the time until the water leaked from the pipe was measured. The hot internal pressure creep test at 40 ° C. and the hot internal pressure creep test at 60 ° C. were determined based on the following criteria.

[Criteria for hot internal pressure creep test (40 ° C and 60 ° C)]
○: The time from the start of the hot internal pressure creep test to breakage of the pipe and the occurrence of a water leak 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 generation of water leak is 10 Over time less than 100 hours ×: The time from the start of hot internal pressure creep test to pipe breakage and water leak is less than 10 hours

(7) Impact resistance The obtained pipe was subjected to a falling weight test at 0 ° C. using a 3 kg weight, and the 50% crack height was measured. As a falling weight test machine, "FALLING DART IMPACT TESTER" manufactured by Yasuda Seiki Seisakusho Co., Ltd. was used. The drop weight test conditions conformed to Annex A of JIS K6741. However, the length of the test piece was 3 cm, and the 50% crack height was calculated by the method described in JIS K7211. Impact resistance was determined according to the following criteria.

[Criteria for impact resistance]
○: 50% crack height is 150 cm or more Δ: 50% crack height is 100 cm or more and less than 150 cm ×: 50% crack height is less than 100 cm

(8) Weathering test The obtained multilayer tube was subjected to a weathering test for 800 hours under the following conditions. As a weather resistance test machine, "METALWEATHER" manufactured by Daipurintes Co., Ltd. was used.

[Weatherability 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 each before and after D

(9) Impact Strength Holding Ratio The obtained multilayer tube was subjected to an impact resistance test in accordance with JIS K6741 or JIS K6742 to determine the impact strength. Specifically, a drop weight test was performed at 0 ° C. using a 3 kg weight. As a falling weight test machine, "FALLING DART IMPACT TESTER" manufactured by Yasuda Seiki Seisakusho Co., Ltd. was used. Moreover, the impact resistance test was similarly done about the multilayer tube which did the said (8) weather resistance test. The impact strength retention rate was determined by the following equation. The impact strength retention rate was determined based on the following criteria.

  Impact strength retention (%) = (Impact strength after weathering test / Impact strength before weathering test) x 100

[Judgment criteria of impact strength retention rate]
○: Impact strength retention rate is 80% or more Δ: Impact strength retention rate is 50% or more and less than 80% ×: Impact strength retention rate is less than 50%

(10) Total light transmittance Only the outer layer of the obtained multilayer tube is cut out, roll press processing is performed under the roll press conditions performed in the evaluation of (1) outer layer strength, thickness 0.20 mm, 0.25 mm, 0. Samples of 30 mm, 0.35 mm, 0.40 mm and 0.50 mm were produced. Since the thickness of each obtained sample had a variation of ± 0.02 mm, the thickness was accurately measured with a micrometer. The total light transmittance of the obtained sample was measured according to JIS K7361-1 using "NDH 2000" manufactured by Nippon Denshoku Kogyo. On a semi-logarithmic graph, the thickness of the sample is plotted on the horizontal axis, and the total light transmittance is plotted on the vertical axis, and the slope of the obtained approximate straight line is taken as a constant A. The total light transmittance per 0.1 mm thickness of the outer layer 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 according to the following equation. The total light transmittance was determined based on the following criteria.

  Total light transmittance (%) = 100 × exp (−A × 0.1) per 0.1 mm thickness of outer layer

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

[Criteria for judging total light transmittance]
○: total light transmittance per 0.1 mm thickness of the outer layer or total light transmittance in the thickness direction of the outer layer is 30% or less Δ: total light transmittance per 0.1 mm thickness of the outer layer and total light in the thickness direction of the outer layer Any one of the transmittances is more than 30% and not more than 50% ×: The total light transmittance per 0.1 mm thickness of the outer layer and the total light transmittance of the outer layer in the thickness direction exceed 50%

(11) Color difference About the obtained multilayer tube, L, a, b value was measured based on JIS-Z8730 using the color difference meter "NR-300" by Nippon Denshoku Industries Co., Ltd. product. Moreover, L, a, b was similarly measured about the multilayer tube which did the said (8) weather resistance test. The color difference before and after the weathering test was determined by the following equation. The color difference was judged according to 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 ×: ΔE is more than 10

(12) Comprehensive judgment: (4) Flat strength, (5) Adhesive strength (40 ° C and 60 ° C), (6) Hot internal pressure creep test (40 ° C and 60 ° C), (7) Impact resistance The score was calculated in each Example and each Comparative Example from the judgment results of (9) impact strength retention rate, (10) total light ray transmittance, and (11) color difference.

The judgment of (4) flat strength is ○: 10 points, x: 0 point (5) The judgment of adhesive strength (40 ° C and 60 ° C) is :: 3 points, Δ: 1 point, x: 0 points 6) Determination of hot internal pressure creep test (40 ° C. and 60 ° C.) ○: 3 points, Δ: 1 point, ×: 0 points. (7) Impact resistance determination is ○: 5 points, Δ3 points, X: 0 points The above (9) impact strength retention rate determination is ○: 3 points,: 1: 1 point, x: 0 points above (10) total light transmittance is ○: 3 points, △: 1 point, x: 0 points The above (11) color difference is ○: 3 points, Δ: 1 point, x: 0 points

[Criteria for comprehensive judgment]
○: The total score is 35 or more. :: The total score is 25 or more, 34 or less. ×: The total score is 24 or less

  The construction and results of the piping (multilayer pipe connector) are shown in Tables 1 and 2 below.

DESCRIPTION OF SYMBOLS 1 ... Multilayer pipe 1a ... Terminal 11 ... Inner layer 12 ... Outer layer 13 ... Adhesive layer 21 ... Multilayer pipe connection body 31 ... Connection object member

Claims (19)

It has an inner layer and an outer layer,
The inner layer is tubular,
The outer layer is disposed on the outer surface of the inner layer,
The tensile strength at 23 ° C. of the inner layer measured in accordance with JIS K6815-2 or JIS K7161-2 is 25 MPa or more and 67 MPa or less, and is measured in accordance with JIS K6815-2 or JIS K7161-2 The tensile elongation at 23 ° C. of the inner layer is 10% or more,
The tensile strength at 23 ° C. of the outer layer measured according to JIS K6815-2 or JIS K7161-2 is 25 MPa or more and 67 MPa or less, and measured according to JIS K6815-2 or JIS K7161-2 Multilayer pipe in which the tensile elongation at 23 ° C. of the outer layer is 10% or more.   After immersing the outer layer in the adhesive for 30 minutes, when the outer layer after the immersion is dried at 60 ° C. for 48 hours, the dried outer layer is measured according to JIS K6815-2 or JIS K7161-2. The multilayer pipe according to claim 1, wherein the tensile strength at 40 ° C is 10 MPa or more.   The multilayer tube according to claim 1 or 2, wherein the material of the outer layer comprises a soft thermoplastic resin.   The multilayer pipe according to claim 3, wherein the soft thermoplastic resin is butyl rubber, ethylene propylene rubber, urethane rubber, silicone rubber, acrylic rubber, fluororubber, or a rubber having a structural unit derived from a diene skeleton.   The multilayer pipe according to claim 3 or 4, wherein the content of the soft thermoplastic resin is 5% by weight or more and 70% by weight or less in 100% by weight of the material of the outer layer.   The multilayer tube according to any one of claims 3 to 5, wherein the material of the outer layer further comprises at least one component of a thermoplastic elastomer and a plasticizer.   The multilayer pipe according to claim 6, wherein a total content of the soft thermoplastic resin and the component is 5 wt% or more and 70 wt% or less in 100 wt% of the material of the outer layer.   The multilayer tube according to any one of claims 3 to 7, wherein the material of the outer layer further comprises a weatherable thermoplastic resin.   The multilayer pipe according to claim 8, wherein the content of the weatherable thermoplastic resin is 30% by weight or more in 100% by weight of the material of the outer layer.   The multilayer pipe according to claim 8 or 9, wherein the degree of polymerization of the weatherable thermoplastic resin is 400 or more and 2,500 or less.   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. Multilayer pipe as described in.   The multilayer pipe according to any one of claims 1 to 11, wherein the impact strength retention ratio of the impact strength after the weathering test to the impact strength before the weathering test is 50% or more. A multilayer pipe according to any one of claims 1 to 12;
And a connection target member connected to the multilayer tube,
A multilayer pipe connector, wherein an adhesive layer is disposed between the multilayer pipe and the connection target member.   After immersing the outer layer in the material of the adhesive layer for 30 minutes, when the outer layer after the immersion is dried at 60 ° C. for 48 hours, it is measured according to JIS K6815-2 or JIS K7161-2 after drying. The multilayer pipe connector according to claim 13, wherein the tensile strength at 40 ° C of the outer layer is 10 MPa or more.   The multilayer pipe connector according to claim 13 or 14, wherein the absolute value of the difference between the SP value of the outer layer and the SP value of the connection target member in the multilayer pipe is 2.0 or less.   The multilayer pipe connector according to any one of claims 13 to 15, wherein an adhesive strength at 40 ° C between the multilayer pipe and the connection target member is 10 MPa or more.   The multilayer pipe connector according to any one of claims 13 to 16, wherein an adhesive strength between the multilayer pipe and the connection target member at 60 ° C is 10 MPa or more.   18. The hot internal pressure creep test at 40 ° C. and a hoop stress of 6.4 MPa, the time until the occurrence of water leakage is 100 hours or more from the start of the hot internal pressure creep test. The multilayer pipe connector according to any one of the above.   The hot internal pressure creep test at 60 ° C. and a hoop stress of 6.4 MPa, the time until the occurrence of water leakage is 100 hours or more from the start of the hot internal pressure creep test. The multilayer pipe connector according to any one of the above.

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