JP7120829B2 - How to connect multi-layer pipes - Google Patents

Description

The present invention relates to a method for connecting a multi-layer pipe comprising an inner layer and an outer layer to a tubular member to be connected.

Many plastic pipes are used for water supply and drainage in buildings such as condominiums, apartments, and detached houses. In addition, when piping is used outdoors or when it is necessary to prevent permeation of oxygen in piping, piping in which an inner layer and an outer layer formed of a highly functional resin composition are integrated is used. ing. For example, "Color Pipe" manufactured by Sekisui Chemical Co., Ltd. has an inner layer made of vinyl chloride resin (PVC resin) and an outer layer made of highly weather-resistant resin, so that it can be used outdoors.

Moreover, when the necessary length of the piping structure is longer than the length of one pipe, or when the piping structure has a bend or the like, a plurality of pipes are connected directly or via joints. In this case, an adhesive layer may be formed at the ends of the pipes and the pipes 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 covered with an outer layer. The pipe main body is made 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-A-2002-254576

In a conventional pipe such as that described in Patent Document 1, pipes are connected to each other via an adhesive layer arranged on the outer surface of the outer layer covering the pipe main body. With this pipe, sufficient connection accuracy may not be obtained when pipes are connected to each other. As a result, the dimensions of the pipes obtained may vary, and when the internal pressure rises due to the passage of water or the like, the connected pipes may come off.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for connecting multilayer pipes, which can improve connection accuracy between a multilayer pipe and a member to be connected.

According to a broad aspect of the present invention, there is provided a method for connecting a multilayer pipe comprising a tubular inner layer and an outer layer disposed on the outer surface of the inner layer to a member to be connected, comprising: A method for connecting multi-layer pipes using a material and a second adhesive material, comprising: a first step of forming a first adhesive layer with the first adhesive material on the outer surface side of the outer layer of the multi-layer pipe; a second step of forming a second adhesive layer from the second adhesive material on the inner surface side of the member to be connected; and forming the second adhesive layer on the outer surface side of the first adhesive layer. A step of connecting the multilayer pipe and the member to be connected by arranging the first adhesive material and the second adhesive material are different adhesive materials, and the first adhesive material However, when the outer layer is immersed in the first solvent at 25 ° C. for 10 minutes, the weight of the outer layer after immersion is increased by 1.25 times or more with respect to the weight of the outer layer before immersion. 1 solvent, and the content of the first solvent is 45% by weight or more in 100% by weight of the first adhesive material.

In a specific aspect of the method for connecting multilayer pipes according to the present invention, the material of the outer layer includes the material of the member to be connected, and the content of the material of the member to be connected is 100% by weight of the material of the outer layer. 90% by weight or less.

In a specific aspect of the method for connecting multilayer pipes according to the present invention, the first adhesive material does not contain or contains a thermoplastic resin, and 100% by weight of the first adhesive material contains The content is 0% by weight or more and 10% by weight or less.

In a specific aspect of the method for connecting multilayer pipes according to the present invention, the second adhesive material contains 35% by weight or less of thermoplastic resin in 100% by weight of the second adhesive material.

In a specific aspect of the method for connecting multilayer pipes according to the present invention, at least one of the first adhesive material and the second adhesive material contains a thermoplastic resin, and the weight of the first adhesive material is 100. % and the total content of the thermoplastic resin in 100% by weight of the second adhesive material is 10% by weight or more and 50% by weight or less.

In a specific aspect of the method for connecting multilayer pipes according to the present invention, in the first step, the first adhesive material and the second adhesive material are applied to the outer surface side of the outer layer of the multilayer pipe. forming the first adhesive layer and the second adhesive layer, and in the second step, bonding the inner surface side of the member to be connected with the first adhesive material and the second adhesive material , forming a first adhesive layer and said second adhesive layer.

In a specific aspect of the method for connecting multilayer pipes according to the present invention, the multilayer pipe and the member to be connected are connected such that the adhesion strength between the multilayer pipe and the member to be connected at 60° C. is 10 MPa or more. do.

In a specific aspect of the method for connecting multilayer pipes according to the present invention, the material of the outer layer contains a resin having a nitrile group or a carbonyl group.

In a specific aspect of the method for connecting multi-layer pipes according to the present invention, when water is passed through the multi-layer pipe connection body in which the multi-layer pipe and the member to be connected are connected at 40° C. and a hoop stress of 6.4 MPa, and connecting the multi-layer pipe and the member to be connected so that the time until water leakage occurs is 100 hours or longer.

In a specific aspect of the method for connecting multi-layer pipes according to the present invention, when water is passed through the multi-layer pipe connection body in which the multi-layer pipe and the member to be connected are connected at 60° C. and a hoop stress of 6.4 MPa, and connecting the multi-layer pipe and the member to be connected so that the time until water leakage occurs is 100 hours or longer.

In a specific aspect of the method for connecting multilayer pipes according to the present invention, the absolute value of the difference between the SP value of the outer layer and the SP value of the member to be connected is 1.0 or less.

A method for connecting a multilayer pipe according to the present invention is a method for connecting a multilayer pipe including a tubular inner layer and an outer layer disposed on the outer surface of the inner layer to a member to be connected. A method for connecting multilayer pipes according to the present invention is a method for connecting multilayer pipes using a first adhesive material and a second adhesive material. A method for connecting multilayer pipes according to the present invention comprises a first step of forming a first adhesive layer with the first adhesive material on the outer surface side of the outer layer of the multilayer pipe. A method for connecting multi-layer pipes according to the present invention comprises a second step of forming a second adhesive layer on the inner surface side of the member to be connected using the second adhesive material. A method for connecting a multi-layer pipe according to the present invention includes the step of connecting the multi-layer pipe and the member to be connected by placing the second adhesive layer on the outer surface side of the first adhesive layer. In the method for connecting multilayer pipes according to the present invention, the first adhesive material and the second adhesive material are different adhesive materials. In the method for connecting multilayer pipes according to the present invention, when the first adhesive material is immersed in the first solvent at 25° C. for 10 minutes, the weight of the outer layer before immersion is: A first solvent is included that increases the weight of the outer layer by a factor of 1.25 or more after soaking. In the method for connecting multilayer pipes according to the present invention, the content of the first solvent is 45% by weight or more in 100% by weight of the first adhesive material. Since the method for connecting a multilayer pipe according to the present invention has the above configuration, it is possible to improve the connection accuracy between the multilayer pipe and the member to be connected.

FIG. 1 is a cross-sectional view for explaining an example of a method for connecting multilayer pipes according to a first embodiment of the present invention.

The present invention will be described in detail below.

(Method of connecting multi-layer pipes)
A method for connecting a multilayer pipe according to the present invention is a method for connecting a multilayer pipe including a tubular inner layer and an outer layer disposed on the outer surface of the inner layer to a member to be connected. A method for connecting multilayer pipes according to the present invention is a method for connecting multilayer pipes using a first adhesive material and a second adhesive material. A method for connecting multilayer pipes according to the present invention comprises a first step of forming a first adhesive layer with the first adhesive material on the outer surface side of the outer layer of the multilayer pipe. In this first step, at least a first adhesive material is used to form the adhesive layer. In this first step, at least a first adhesive layer is formed. A method for connecting multi-layer pipes according to the present invention comprises a second step of forming a second adhesive layer on the inner surface side of the member to be connected using the second adhesive material. In this second step, at least a second adhesive material is used to form the adhesive layer. In this second step, at least a second adhesive layer is formed. A method for connecting a multi-layer pipe according to the present invention includes the step of connecting the multi-layer pipe and the member to be connected by placing the second adhesive layer on the outer surface side of the first adhesive layer. In this step, by inserting the multilayer pipe into the member to be connected, the member to be connected is arranged on the outer surface side of the first adhesive layer, and the multilayer pipe is disposed on the inner surface side of the second adhesive layer. to place.

In the method for connecting multilayer pipes according to the present invention, the first adhesive material and the second adhesive material are different adhesive materials.

In the method for connecting multilayer pipes according to the present invention, the first adhesive material contains a specific first solvent. In the method for connecting multilayer pipes according to the present invention, when the first adhesive material is immersed in the first solvent at 25° C. for 10 minutes, the weight of the outer layer before immersion is: A first solvent is included that increases the weight of the outer layer by a factor of 1.25 or more after soaking.

In the method for connecting multilayer pipes according to the present invention, the content of the first solvent is 45% by weight or more in 100% by weight of the first adhesive material.

Since the method for connecting a multilayer pipe according to the present invention has the above configuration, it is possible to improve the connection accuracy between the multilayer pipe and the member to be connected.

In the method for connecting a multi-layer pipe according to the present invention, it is possible to improve the connection accuracy between the multi-layer pipe and the member to be connected. On the other hand, it is possible to satisfactorily insert the multi-layer pipe to a desired length, and to suppress variations in the dimensions of the obtained pipe. Since the method for connecting multilayer pipes according to the present invention has the above configuration, connection reliability (connection strength between the multilayer pipe and the member to be connected) can be enhanced. In the method for connecting multi-layer pipes according to the present invention, it is possible to make it difficult for the multi-layer pipe and the member to be connected to separate from each other even when the internal pressure increases due to the passage of water or the like.

In the method for connecting multi-layer pipes according to the present invention, especially since the specific first adhesive layer is provided, the insertion resistance between the multi-layer pipe and the member to be connected can be reduced. Further, in the method for connecting multilayer pipes according to the present invention, since the second adhesive layer is provided in addition to the first adhesive layer, connection reliability (connection strength between the multilayer pipe and the member to be connected) is improved. can increase That is, in the method for connecting multi-layer pipes according to the present invention, since the first adhesive layer and the second adhesive layer are provided, it is possible to improve connection accuracy and connection reliability.

By the method for connecting multilayer pipes according to the present invention, it is possible to manufacture a multilayer pipe connector including a multilayer pipe and a member to be connected connected to the multilayer pipe.

Formation of the first adhesive layer may be performed by applying the first adhesive material. The formation of the second adhesive layer may be performed by applying the second adhesive material.

The second adhesive material preferably contains a thermoplastic resin and a solvent. The solvent contained in the second adhesive material preferably contains the second solvent described later.

In the present invention, a member to be connected means a member that is used by being connected to a multi-layer pipe. In the present invention, the member to be connected includes, for example, a joint for connecting a first pipe (first multilayer pipe) and a second pipe (second multilayer pipe), and a first pipe (second 1 multi-layered pipe), and a second pipe having a diameter different from that of the first pipe.

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

FIG. 1 is a cross-sectional view for explaining an example of a method for connecting multilayer pipes according to a first embodiment of the present invention.

FIG. 1(a) is a cross-sectional view showing an example of the first step (adhesive layer forming step).

The multilayer pipe 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 pipe 1 .

The outer layer 12 is arranged on the outer surface of the inner layer 11 . The outer layer 12 is arranged over the entire outer surface of the inner layer 11 . The outer layer preferably extends to both ends of the multilayer tube. The outer layer is preferably arranged in a tubular shape.

A first adhesive material is applied onto the outer surface of the outer layer 12 to form the first adhesive layer 2 . As a result, the first adhesive layer 2 is formed on the outer surface side of the outer layer 12 . The first adhesive layer 2 is arranged on the outer surface of the outer layer 12 . A first adhesive layer 2 is arranged on the outer surface of the outer layer 12 at the end of the multilayer tube 1 . The first adhesive layer 2 is arranged on the outer surface of the outer layer 12 so as to reach the end 1a of the multilayer pipe 1 . The first adhesive layer may be arranged on a partial region of the outer surface of the outer layer. The first adhesive layer may not be disposed on the entire outer surface of the outer layer up to the end of the multilayer pipe at the end of the multilayer pipe, and may be disposed on a partial region of the end of the multilayer pipe. may be

FIG. 1B is a cross-sectional view showing an example of the second step (adhesive layer forming step).

A second adhesive material is applied to the inner surface of the connection target member 3 to form a second adhesive layer 4 . As a result, the second adhesive layer 4 is formed on the inner surface side of the member 3 to be connected. The second adhesive layer 4 is arranged on the inner surface of the member 3 to be connected. The second adhesive layer 4 is arranged on the inner surface at the end of the member 3 to be connected. The second adhesive layer 4 is arranged on the inner surface of the member 3 to be connected so as to reach the end 3a of the member 3 to be connected. The second adhesive layer may be arranged on a partial region of the inner surface of the member to be connected. The second adhesive layer may not be arranged on the entire inner surface of the connection target member to the end of the connection target member at the end of the connection target member, and may be disposed on a part of the end of the connection target member. may be located in the area of

FIG. 1(c) is a cross-sectional view showing an example of a process of connecting a multilayer pipe and a member to be connected.

The first adhesive layer 2 is arranged on the outer surface side of the outer layer 12 . The second adhesive layer 4 is arranged on the inner surface side of the member 3 to be connected. The member to be connected 3 is arranged on the outer surface side of the first adhesive layer 2 , and the multilayer pipe 1 is arranged on the inner surface side of the second adhesive layer 4 . The multilayer pipe 1 and the member to be connected 3 are arranged on the first adhesive layer 2 arranged on the outer surface of the outer layer 12 at the end of the multilayer pipe 1 and on the inner surface at the end of the member 3 to be connected. It is connected through the second adhesive layer 4 which is connected. Through this process, a multi-layer tube connector 5 including the multi-layer tube 1 and the member 3 to be connected can be obtained. The connection target member may be arranged on the outer surface side of the first adhesive layer, and the connection target member may not be arranged on the entire outer surface side of the first adhesive layer. The multilayer pipe need only be arranged on the inner surface side of the second adhesive layer, and the multilayer pipe need not be arranged on the entire inner surface side of the second adhesive layer.

(First step)
In the first step, a first adhesive layer is formed on the outer surface side of the outer layer using the first adhesive material. The first adhesive layer and the second adhesive layer may be formed on the outer surface side of the outer layer using the first adhesive material and the second adhesive material. In addition to the first adhesive layer, a second adhesive layer may be arranged on the outer surface side of the outer layer.

In the first step, after forming the first adhesive layer with the first adhesive material on the outer surface of the outer layer, the second adhesive layer is formed on the outer surface of the first adhesive layer. An adhesive material may form the second adhesive layer.

In the first step, after forming a second adhesive layer with the second adhesive material on the outer surface of the outer layer, the first adhesive is applied on the outer surface of the second adhesive layer. A material may form the first adhesive layer.

In the first step, an adhesive material other than the first adhesive material and the second adhesive material may be used. In the first step, an adhesive layer different from the first adhesive layer and the second adhesive layer may be disposed.

(Second step)
In the second step, a second adhesive layer is formed on the inner surface side of the member to be connected using the second adhesive material. A first adhesive layer and a second adhesive layer may be formed on the inner surface side of the member to be connected from the first adhesive material and the second adhesive material. In addition to the second adhesive layer, the first adhesive layer may be arranged on the inner surface side of the member to be connected.

In the second step, after forming the second adhesive layer with the second adhesive material on the inner surface of the member to be connected, the second adhesive layer is formed on the inner surface of the second adhesive layer. The first adhesive layer may be formed from one adhesive material.

In the second step, after the first adhesive layer is formed on the inner surface of the member to be connected using the first adhesive material, the first adhesive layer is formed on the inner surface of the first adhesive layer. The second adhesive layer may be formed from two adhesive materials.

In the second step, an adhesive material other than the first adhesive material and the second adhesive material may be used. In the second step, an adhesive layer different from the first adhesive layer and the second adhesive layer may be disposed.

(Order of first step and second step)
The order in which the first step and the second step are performed is not particularly limited. After performing the second step, the first step may be performed.

When two types of adhesive materials are used, after the first type of adhesive material is used in the first step and the second step, the second type of adhesive material is used in the first step and the second step. may be used in

(Step of connecting multi-layer pipe and member to be connected (third step))
In the third step, the multilayer pipe and the member to be connected are connected by arranging the second adhesive layer on the outer surface side of the first adhesive layer.

In the third step, the multilayer pipe and the member to be connected are preferably connected so that the adhesion strength between the multilayer pipe and the member to be connected at 60° C. is 10 MPa or more, and is 15 MPa or more. It is more preferable to connect the multilayer pipe and the member to be connected as follows. Adhesive strength can be raised further as the said adhesive strength is more than the said minimum.

The adhesive strength at 60° C. between the multi-layer pipe and the member to be connected serves as an index of short-term connection reliability.

The adhesive strength at 60° C. between the multi-layer pipe and the member to be connected can be measured 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 are obtained. In addition, the adhesive material (first adhesive material, etc.) applied to the outer layer is applied to the surface of the first test piece, and the adhesive material (second adhesive material, etc.) applied to the connection target member is applied to the surface of the second test piece. adhesive material, etc.). The surface of the first test piece coated with the adhesive material and the surface of the second test piece coated with the adhesive material are superimposed to obtain a laminate. In the obtained laminate, a layer adhered by the material of the first adhesive layer, the material of the second adhesive layer, etc. is arranged between the first test piece and the second test piece. It is The laminate may be obtained by cutting out a multi-layer tube connector.

The obtained laminate is subjected to a tensile test under conditions of 60° C. and a tensile speed of 5 mm/min. The adhesive strength can be obtained by the following formula from the breaking load when the laminate is broken and the adhesion area of the first test piece and the second test piece. As the tensile tester, for example, Shimadzu Corporation's "Desktop Precision Universal Testing Machine AGX-X" can be used.

Adhesion strength (MPa) = breaking load (N) / adhesion area (mm ² )

From the viewpoint of increasing the mechanical strength and connection strength of the multi-layer pipe connection over a long period of time, in the third step, the multi-layer pipe connection in which the multi-layer pipe and the member to be connected are connected is heated at 40°C. And it is preferable to connect the multi-layer pipe and the member to be connected so that the time until water leakage occurs is 100 hours or more when water is flowed with a hoop stress of 6.4 MPa.

From the viewpoint of increasing the mechanical strength and connection strength of the multi-layer pipe connection over a long period of time, in the third step, the multi-layer pipe connection in which the multi-layer pipe and the member to be connected are connected is heated at 60°C. And it is preferable to connect the multi-layer pipe and the member to be connected so that the time until water leakage occurs is 100 hours or more when water is flowed with a hoop stress of 6.4 MPa.

The time until water leakage occurs is an index of long-term connection reliability.

Other details of the multi-layer pipe, the member to be connected, the first adhesive material, the second adhesive material, and the multi-layer pipe connector will be described below.

(multilayer pipe)
The multi-layer tube comprises a tubular inner layer and an outer layer on the outer surface of the inner layer. The outer layer is preferably tubular. The multilayer pipe according to the present invention may have a two-layer structure, a three-layer structure, or a three-layer or more structure. The outer layer is preferably the outermost layer (outermost layer) of the multilayer pipe. When the outer layer is not the outermost layer of the multilayer pipe, a layer having a thickness of 3 mm or less may be arranged on the outer surface of the outer layer.

[Inner layer]
From the viewpoint of suppressing deformation of the multilayer pipe, the inner layer material is preferably a material having a certain degree of strength. Examples of materials for the inner layer include polyvinyl chloride (PVC) and polyvinylidene fluoride (PVDF). Only one material may be used for the inner layer, or two or more materials may be used in combination.

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 unsaturated bonds copolymerizable with vinyl chloride monomers, and polymers and copolymers other than vinyl chloride. A graft polymer obtained by graft-polymerizing vinyl chloride to a polymer may be used. As for the said vinyl-chloride-type resin, only 1 type may be used and 2 or more types may be used together.

The monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer is not particularly limited, and includes 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 Examples include N-substituted maleimide compounds such as maleimide and N-cyclohexylmaleimide. As for the monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer, only one type may be used, or two or more types may be used in combination.

The polymers and copolymers graft-copolymerized with vinyl chloride are not particularly limited, and include ethylene-vinyl acetate copolymers, ethylene-vinyl acetate-carbon monoxide copolymers, ethylene-ethyl acrylate copolymers, ethylene- Butyl acrylate-carbon monoxide copolymer, acrylonitrile-butadiene copolymer, polyurethane, chlorinated polyethylene, chlorinated polypropylene and the like. The polymers and copolymers graft-copolymerized with vinyl chloride may be used alone or in combination of two or more.

The degree of polymerization of the vinyl chloride resin is preferably 100 or more and preferably 10,000 or less. When the degree of polymerization is equal to or higher than the lower limit, long-term performance such as fatigue properties is less likely to be impaired. When the degree of polymerization is equal to or less than the upper limit, it is not necessary to use a high temperature during molding, and processability is further improved.

The vinyl chloride-based 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.

[Outer layer]
The material of the outer layer is not particularly limited. Materials for the outer layer include polyvinyl chloride (PVC), acrylonitrile-styrene resin (AS resin), acrylonitrile-ethylene-propylene-styrene resin (AES resin), polyvinylidene fluoride (PVDF), polycarbonate resin (PC), and polymethacrylic. Examples include methyl acid (PMMA) and acrylonitrile-styrene-acrylate resin (ASA resin). From the viewpoint of practical use outdoors, the material of the outer layer is preferably a weather-resistant material, preferably a weather-resistant resin. From the viewpoint of actual use outdoors, the material of the outer layer is preferably a material having higher weather resistance than the material of the inner layer.

Regarding whether or not the resin has weather resistance, the resin is judged to have weather resistance when the color difference before and after the weather resistance test is 5 or less when the following weather resistance test is performed. The resin after the weather resistance test is equivalent to the resin after being left outdoors for about 10 years.

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

Driving 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

The above color difference is obtained by measuring the L, a, and 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., and using the following formula. is ΔE calculated by

ΔE=[(ΔL) ² +(Δa) ² +(Δb) ² ] ^1/2

The material of the outer layer is polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), acrylonitrile-styrene resin (AS resin), acrylonitrile-ethylene-propylene-styrene resin (AES resin), or acrylonitrile-styrene-acrylate resin. (ASA resin) is preferably included. Only one kind of material for the outer layer may be used, or two or more kinds thereof may be used in combination.

The outer layer may be used in combination with other materials as long as the effects of the present invention are not impaired. For example, in order to further improve the impact resistance and mechanical strength, acrylonitrile-butadiene-styrene resin (ABS resin), acrylic rubber, methyl methacrylate-butadiene-styrene resin (MBS), polyimide resin, etc. are added to the outer layer. It can be used in combination with materials.

By using the material for the outer layer, the weather resistance of the multi-layer pipe can be enhanced, and the multi-layer pipe can be used outdoors.

The material of the outer layer may not contain the material of the member to be connected. From the viewpoint of improving connection accuracy between the multilayer pipe and the member to be connected, the material of the outer layer preferably includes the material of the member to be connected. When the member to be connected has a multilayer structure, the material of the outer layer preferably contains the material of the inner layer (innermost layer) of the member to be connected. The content of the material of the member to be connected preferably exceeds 0% by weight, preferably 90% by weight or less, and more preferably 80% by weight or less in 100% by weight of the material of the outer layer. When the content of the material of the member to be connected contained in the material of the outer layer is equal to or less than the above upper limit, the effect of the present invention can be sufficiently exhibited, and the accuracy of connection between the multilayer pipe and the member to be connected can be further improved. can.

Conventionally, when the content of the material of the member to be connected exceeds 90% by weight in 100% by weight of the material of the outer layer, even if one type of adhesive material is used, the outer layer after application of the adhesive material and the connection object after application of the adhesive material Since there was no difference in the degree of swelling and elastic modulus with the member, the multilayer pipe and the member to be connected could be satisfactorily connected. However, when the content of the material of the member to be connected is 90% by weight or less in 100% by weight of the material of the outer layer, the use of only one type of adhesive material does not allow the connection between the outer layer after application of the adhesive material and the connection after application of the adhesive material. Since there is a difference in the degree of swelling and elastic modulus with the target member, the insertion resistance increases, and the multilayer pipe and the member to be connected may not be satisfactorily connected.

For example, a projection may be provided on the inner peripheral surface of the connection target member at the central portion in the length direction of the connection target member. When the content of the material of the member to be connected is 90% by weight or less in 100% by weight of the material of the outer layer, and when using one type of adhesive material, the end of the multilayer pipe is inserted so that it contacts the convex portion. Sometimes I can't.

In the method for connecting multi-layer pipes according to the present invention, a specific adhesive material is used. It is possible to further improve the connection accuracy between the and the connection target member.

From the viewpoint of further increasing the connection strength, the material of the outer layer preferably contains a resin having a nitrile group or a carbonyl group. Nitrile and carbonyl groups have an aprotic polarity. In particular, when the material of the member to be connected is vinyl chloride, the outer layer and the member to be connected are easily compatible with each other, and the connection strength can be further increased. Moreover, the resin having the nitrile group or the carbonyl group is preferably a resin in which all the polymers constituting the resin have the nitrile group or the carbonyl group. When the resin having a nitrile group or a carbonyl group is a block copolymer, if it contains a polymer having no nitrile group or a carbonyl group, the portion where the outer layer and the member to be connected are easily compatible, and the The strength of the connection may decrease over time because it is divided into areas where it is difficult to connect. Further, when the material of the outer layer is a resin having only a functional group having protonic polarity, when the material of the member to be connected is vinyl chloride, thermal decomposition by protons is promoted, and the connection strength is increased. May decrease over time.

[Other details of multi-layer pipe]
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 includes a thermoplastic resin layer, a fiber reinforced resin layer, a gas barrier layer, a metal layer, an adhesive layer, and the like. can be selected and combined as appropriate.

Examples of the material for the thermoplastic resin layer include vinyl chloride resin.

Examples of the fiber-reinforced resin layer include layers in which a thermoplastic resin and reinforcing fibers are combined. 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. These reinforcing fibers include continuous fibers arranged in the longitudinal direction, continuous fibers arranged in the longitudinal direction and continuous fibers perpendicular to or crossing the continuous fibers arranged in the longitudinal direction, and fibers of finite length. It is used when it is distributed.

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

From the viewpoint of practical use and the viewpoint of good weather resistance, the thickness of the multi-layer pipe is preferably 2.2 mm or more, more preferably 2.5 mm or more, and preferably 19 mm or less, more preferably 15 mm. It is below.

From the viewpoint of practical use outdoors and the viewpoint of good weather resistance, the thickness of the outer layer is preferably 20 μm or more, more preferably 40 μm or more, and preferably 500 μm or less, more preferably 350 μm or less. be.

From the viewpoint of practical use and the viewpoint of good weather resistance, the thickness of the inner layer is preferably 1.7 mm or more, more preferably 2.0 mm or more, and preferably 19 mm or less, more preferably 15 mm or less. is.

Various additives may be used in the multi-layer pipe as required. Examples of the additives include stabilizers, stabilizing aids, lubricants, processing aids, impact modifiers, heat-resistant improvers, antioxidants, ultraviolet absorbers, light stabilizers, fillers, pigments, and plasticizers. is mentioned. Only one of the above additives may be used, or two or more thereof may be used in combination.

The stabilizer is not particularly limited, and includes heat stabilizers, heat stabilization aids, and the like. The heat stabilizer is 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 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 and the like. Only one kind of the heat stabilizer may be used, or two or more kinds thereof may be used in combination.

The heat stabilization aid is not particularly limited, and examples thereof include epoxidized soybean oil, phosphate ester, polyol, hydrotalcite, and zeolite. Only one type of the heat stabilization aid may be used, or two or more types may be used in combination.

The lubricants include internal lubricants and external lubricants. The internal lubricant is used for the purpose of reducing the flow viscosity of the molten resin during molding and preventing frictional heat generation. The internal lubricant is not particularly limited, and includes butyl stearate, lauryl alcohol, stearyl alcohol, epoxy soybean oil, glycerin monostearate, stearic acid, bisamide, and the like. The external lubricant is used for the purpose of increasing the sliding effect between the molten resin and the metal surface during molding. The external lubricant is not particularly limited, and includes paraffin wax, polyolefin wax, ester wax, montanic acid wax, and the like. Only one type of the lubricant may be used, or two or more types may be used in combination.

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

The impact modifier is not particularly limited, and includes methyl methacrylate-butadiene-styrene copolymer (MBS), chlorinated polyethylene, and acrylic rubber. Only one type of the impact modifier may be used, or two or more types may be used in combination.

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

The antioxidant is not particularly limited, and includes phenolic antioxidants and the like. Only one kind of the antioxidant may be used, or two or more kinds thereof may be used in combination.

The ultraviolet absorber is not particularly limited, and includes salicylic acid ester-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers. As for the said ultraviolet absorber, only 1 type may be used and 2 or more types may be used together.

The light stabilizer is not particularly limited, and includes hindered amine light stabilizers and the like. As for the said light stabilizer, only 1 type may be used and 2 or more types may be used together.

The filler is not particularly limited, and examples thereof include calcium carbonate and talc. Only one kind of the filler may be used, or two or more kinds thereof may be used in combination.

The pigment is not particularly limited, and includes organic pigments and inorganic pigments. Examples of the organic pigments include azo-based organic pigments, phthalocyanine-based organic pigments, threne-based organic pigments, and dye lake-based organic pigments. Examples of the inorganic pigments include oxide-based inorganic pigments, molybdenum chromate-based inorganic pigments, sulfide/selenide-based inorganic pigments, ferrocyanide-based inorganic pigments, and the like. Only one type of the pigment may be used, or two or more types may be used in combination.

The plasticizer may be added for the purpose of improving workability during molding. The plasticizer is not particularly limited and includes dibutyl phthalate, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate and the like. Only one type of the plasticizer may be used, or two or more types may be used in combination.

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

From the viewpoint of improving connection accuracy, the material of the member to be connected is preferably polyvinyl chloride.

The member to be connected is not particularly limited as long as it is a member that is 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 single-layer pipes and multi-layer pipes.

(First adhesive material and second adhesive material)
[First adhesive material]
The first adhesive material contains a solvent (first solvent). Since the first adhesive material contains a specific solvent, it can swell the outer surface of the outer layer when the specific solvent is applied to the outer surface of the outer layer. Insertion resistance when connecting the connection object member can be reduced, and connection accuracy between the multilayer pipe and the connection object member can be improved. Only one type of the first adhesive material may be used, or two or more types may be used in combination.

In the first solvent, when the outer layer is immersed in the first solvent at 25 ° C. for 10 minutes, the weight of the outer layer after immersion is 1.25 times the weight of the outer layer before immersion. It is a solvent that increases the above.

The weight increase of the outer layer can be measured, for example, as follows.

After the outer layer is immersed in the solvent at 25° C. for 10 minutes, the immersed outer layer is dried. After that, the weight increase of the outer layer calculated by the following formula (1) is obtained.

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)

The first solvent is the weight increase calculated by the above formula (1) when the outer layer is immersed in the first solvent at 25 ° C. for 10 minutes and then the outer layer after immersion is dried. is 1.25 times or more.

From the viewpoint of further improving the connection accuracy, the first solvent has the above formula when the outer layer is immersed in the first solvent at 25 ° C. for 10 minutes and then the outer layer after immersion is dried. The weight increase calculated in (1) is preferably 1.35 times or more, more preferably 1.45 times or more. From the viewpoint of maintaining high strength of the multi-layer pipe and the multi-layer pipe connector, the first solvent is prepared by immersing the outer layer in the first solvent at 25° C. for 10 minutes, and then removing the outer layer after immersion. It is preferable that the solvent has a weight increase calculated by the above formula (1) of preferably 2.00 times or less, more preferably 1.80 times or less when dried. If the weight increase calculated by the above formula (1) exceeds 2.00 times, compared to the case where it is 2.00 times or less, it takes time until the solvent is sufficiently dried after bonding the multilayer pipe and the member to be connected. time becomes longer, the strength of the connection decreases, and the disconnection may occur.

The first solvent can be appropriately selected according to the material of the outer layer. The first solvent may be an inorganic solvent or an organic solvent. Only one kind of the first solvent may be used, or two or more kinds thereof may be used in combination.

Examples of the first solvent include tetrahydrofuran (THF), methyl ethyl ketone (MEK), acetone, ethyl acetate, cyclohexanone, toluene, and dichloromethane.

The content of the first solvent (the total content when a plurality of first solvents are used) is 45% by weight or more in 100% by weight of the first adhesive material. If the content of the first solvent is less than 45% by weight, the insertion resistance increases when connecting the multi-layer pipe and the member to be connected, making it impossible to properly insert the multi-layer pipe and the member to be connected. Accuracy may be poor.

In 100% by weight of the first adhesive material, the content of the first solvent (the total content when using a plurality of first solvents) is preferably 60% by weight or more, more preferably 80% by weight. % or more. When the content of the first solvent is equal to or higher than the lower limit, the insertion resistance when connecting the multi-layer pipe and the member to be connected can be further reduced, and the connection accuracy between the multi-layer pipe and the member to be connected is further improved. be able to.

From the viewpoint of promoting the swelling of the outer surface of the outer layer and further reducing the insertion resistance when connecting the multi-layer pipe and the member to be connected, the first adhesive material preferably does not contain a thermoplastic resin. preferable. From the viewpoint of enhancing the adhesive strength of the first adhesive layer and enhancing connection reliability, the first adhesive material preferably contains a thermoplastic resin.

When the first adhesive material contains a thermoplastic resin, the content of the thermoplastic resin in 100% by weight of the first adhesive material is preferably 10% by weight or less, more preferably 5% by weight or less. be. When the content of the thermoplastic resin is equal to or less than the upper limit, the viscosity of the first adhesive material can be improved, and the insertion resistance when connecting the multi-layer pipe and the member to be connected can be reduced. .

From the viewpoint of reducing the insertion resistance when connecting the multilayer pipe and the member to be connected, the content of the thermoplastic resin in 100% by weight of the first adhesive material is 0% by weight or more and 10% by weight or less. Preferably. That is, the first adhesive material does not contain a thermoplastic resin or contains a thermoplastic resin, and the content of the thermoplastic resin is 0% by weight or more and 10% by weight or less in 100% by weight of the first adhesive material. is preferred.

The length of the first adhesive layer in the axial direction of the multilayer pipe (the length of the portion of the first adhesive layer located on the outer surface of the outer layer in the axial direction of the multilayer pipe) is preferably is 5 mm or more, more preferably 10 mm or more, preferably 300 mm or less, more preferably 250 mm or less. When the length is equal to or more than the lower limit and equal to or less than the upper limit, connection accuracy and connection reliability can be further improved.

[Second adhesive material]
The second adhesive material preferably contains a thermoplastic resin and a solvent. Moreover, the solvent contained in the second adhesive material preferably contains a second solvent described later. When the second adhesive material contains a thermoplastic resin and a solvent (second solvent), when the specific solvent is applied to the inner surface of the connection target member, the inner surface of the connection target member As a result, the insertion resistance when connecting the multi-layer pipe and the member to be connected can be reduced, and the accuracy of connection between the multi-layer pipe and the member to be connected can be improved. Only one type of the second adhesive material may be used, or two or more types may be used in combination.

From the viewpoint of further improving connection accuracy between the multilayer pipe and the member to be connected, the second adhesive material preferably contains chlorinated vinyl chloride resin (CPVC) or vinyl chloride resin as the thermoplastic resin.

In the second solvent, when the connection target member is immersed in the second solvent at 25° C. for 10 minutes, the weight of the connection target member after immersion relative to the weight of the connection target member before immersion It is a solvent that increases the weight of by more than 1.10 times.

The amount of weight increase of the connection target member can be measured, for example, as follows.

After the member to be connected is immersed in a solvent at 25° C. for 10 minutes, the member to be connected after immersion is dried. After that, the weight increase amount of the member to be connected calculated by the following formula (2) is obtained.

Weight increase = (weight of connection target member after immersion - weight of connection target member after drying + weight of connection target member before immersion) / weight of connection target member before immersion (2)

The second solvent is calculated by the above formula (2) when the member to be connected is immersed in the second solvent at 25° C. for 10 minutes and then the member to be connected after immersion is dried. It is a solvent that has a weight increase of 1.10 times or more.

The second solvent is calculated by the above formula (2) when the member to be connected is immersed in the second solvent at 25° C. for 10 minutes and then the member to be connected after immersion is dried. It is preferable that the solvent has a weight increase of 1.20 times or more, more preferably 1.30 times or more. The second solvent is calculated by the above formula (2) when the member to be connected is immersed in the second solvent at 25° C. for 10 minutes and then the member to be connected after immersion is dried. It is preferable that the solvent has a weight increase of 2.00 times or less, more preferably 1.80 times or less. If the weight increase calculated by the above formula (2) exceeds 2.00 times, compared to the case where it is 2.00 times or less, it takes time until the solvent is sufficiently dried after bonding the multilayer pipe and the member to be connected. time becomes longer, the strength of the connection decreases, and the disconnection may occur.

The second solvent can be appropriately selected according to the material of the member to be connected. The second solvent may be an inorganic solvent or an organic solvent. Only one kind of the second solvent may be used, or two or more kinds thereof may be used in combination.

Examples of the second solvent include tetrahydrofuran (THF), methyl ethyl ketone (MEK), acetone, ethyl acetate, cyclohexanone, toluene, and dichloromethane.

In 100% by weight of the second adhesive material, the content of the second solvent (the total content when using a plurality of second solvents) is preferably 30% by weight or more, more preferably 40% by weight. % or more, more preferably 50 wt % or more. If the content of the second solvent is less than 30% by weight, the insertion resistance increases when connecting the multilayer pipe and the member to be connected, and the insertion cannot be performed satisfactorily, resulting in the connection between the multilayer pipe and the member to be connected. Accuracy may be poor.

From the viewpoint of enhancing the adhesive strength of the second adhesive layer and enhancing connection reliability, the second adhesive material preferably contains a thermoplastic resin.

When the second adhesive material contains a thermoplastic resin, the content of the thermoplastic resin in 100% by weight of the second adhesive material is preferably more than 10% by weight, preferably 35% by weight or less, It is more preferably 30% by weight or less, still more preferably 25% by weight or less. When the content of the thermoplastic resin is equal to or higher than the lower limit, the adhesive strength of the second adhesive layer can be further enhanced, and the connection reliability can be further enhanced. When the content of the thermoplastic resin is equal to or less than the upper limit, the viscosity of the second adhesive material can be improved, and the insertion resistance when connecting the multi-layer pipe and the member to be connected can be reduced. .

The length of the second adhesive layer in the axial direction of the member to be connected (for the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected ) is preferably 5 mm or more, more preferably 10 mm or more, preferably 300 mm or less, more preferably 250 mm or less. When the length is equal to or more than the lower limit and equal to or less than the upper limit, connection accuracy and connection reliability can be further improved.

[Other Details of First Adhesive Material and Second Adhesive Material]
The first adhesive material and the second adhesive material are different adhesive materials.

The first solvent and the second solvent may be the same solvent or different solvents.

From the viewpoint of promoting the swelling of the outer surface of the outer layer or the inner surface of the member to be connected and improving the connection reliability, one of the first adhesive material and the second adhesive material is thermoplastic. It is preferable not to contain resin.

At least one of the first adhesive material and the second adhesive material preferably contains a thermoplastic resin from the viewpoint of maintaining high strength of the multi-layer pipe and the multi-layer pipe connector.

As the thermoplastic resin contained in the first adhesive material or the second adhesive material, acrylonitrile-butadiene-styrene resin (ABS resin), acrylonitrile-ethylene-propylene-styrene resin (AES resin), acrylonitrile-styrene - acrylate resins (ASA resins), polyethylene terephthalate (PET), polyvinyl chloride (PVC), chlorinated vinyl chloride resins (CPVC), polymethyl methacrylate (PMMA), rubber-containing acrylic resins, and vinyl chloride and vinyl acetate; and the like.

When at least one of the first adhesive material and the second adhesive material contains a thermoplastic resin, the content of the thermoplastic resin in 100% by weight of the first adhesive material and the second adhesive material and the thermoplastic resin content in 100% by weight of the adhesive material is preferably 10% by weight or more, more preferably 12% by weight or more. When at least one of the first adhesive material and the second adhesive material contains a thermoplastic resin, the content of the thermoplastic resin in 100% by weight of the first adhesive material and the second adhesive material and the thermoplastic resin content in 100% by weight of the adhesive material is preferably 50% by weight or less, more preferably 40% by weight or less. Connection reliability can be maintained over a long period of time as the sum total of the said content is more than the said minimum. When the total content is equal to or less than the upper limit, the viscosity of the adhesive portion can be improved, and the connection reliability can be improved.

When the content of the thermoplastic resin in 100% by weight of the first adhesive material is greater than the content of the thermoplastic resin in 100% by weight of the second adhesive material, the first bonding is performed as follows. Layer formation is preferred. That is, in the first step, after the second adhesive layer is formed on the outer surface of the outer layer with the second adhesive material, the first adhesive layer is formed on the outer surface of the second adhesive layer. It is preferable to form the first adhesive layer with the adhesive material of . By adopting the formation order described above, the swelling of the outer surface of the outer layer can be promoted, and the connection accuracy can be further increased.

When the content of the thermoplastic resin in 100% by weight of the second adhesive material is greater than the content of the thermoplastic resin in 100% by weight of the first adhesive material, the second bonding is performed as follows. Layer formation is preferred. That is, in the second step, after the first adhesive layer is formed on the inner surface of the member to be connected using the first adhesive material, the adhesive layer is formed on the inner surface of the first adhesive layer. Preferably, the second adhesive layer is formed from a second adhesive material. By adopting the formation order described above, the swelling of the inner surface of the member to be connected can be promoted, and the connection accuracy can be further increased.

(Multi-layer tube connector)
The multi-layer pipe connector includes the multi-layer pipe and a member to be connected connected to the multi-layer pipe. The multi-layer tube connector includes the multi-layer tube, a member to be connected connected to the multi-layer tube, a first adhesive layer, and a second adhesive layer. The multilayer pipe and the member to be connected are connected by the method for connecting a multilayer pipe according to the present invention. The multilayer pipe connector is, for example, a pipe.

When the multi-layer pipe has a nominal diameter of 50A and the multi-layer pipe without the first adhesive layer is inserted into the member to be connected on which the second adhesive layer is not formed with a load of 100 N, the multi-layer pipe It is preferable to confirm the ratio of the insertion length of the pipe to the insertable length defined by the connection target member (insertion length of the multi-layer pipe/insertable length defined by the connection target member). The above ratio (insertion length of the multilayer pipe/insertable length defined by the member to be connected) is preferably 1/3 or more, and preferably 2/3 or less. When the above ratio is equal to or higher than the above lower limit, deformation of the member to be connected is less likely to occur, and the strength of the multi-layer pipe connection can be further increased. When the above ratio is equal to or less than the above upper limit, the strength of the multi-layer tube connector can be further increased.

The first adhesive layer in the multi-layer pipe connector may be exposed from the end of the member to be connected on the side of the multi-layer pipe, and may not be exposed from the end of the member to be connected on the side of the multi-layer pipe. good too. The second adhesive layer in the multi-layer tube connector may be exposed from the end of the multi-layer tube on the side of the member to be connected, and should not be exposed from the end of the member to be connected on the side of the multi-layer tube. good too.

From the viewpoint of further increasing connection reliability, the absolute value of the difference between the SP value of the outer layer of the multilayer pipe and the SP value of the member to be connected is preferably 1.0 or less, more preferably 0.7. It is below. When the absolute value of the difference exceeds 1.0, the compatibility of each material may be inferior to the case where the absolute value of the difference is 1.0 or less, and the adhesive strength may decrease. When the member to be connected has a multilayer structure, the SP value of the member to be connected means the SP value of the inner layer (innermost layer) of the member to be connected. The SP value represents a measure of affinity between substances and is also called solubility parameter. It is known that the smaller the absolute value of the SP value difference, the higher the affinity.

The above SP value can be obtained from literature information, as well as by Hansen's or Hoy's calculation method, Fedors' estimation method, or the like.

The above SP value is preferably obtained using the Fedors estimation method. For compounds having a glass transition point of 25° C. or higher, when the SP value is calculated using the Fedors estimation method, the following values can be used in calculating the SP value. When the number (n) of repeating units in the main chain of the compound is 3 or more, molar molecular volume +2n. When the number of repeating units (n) in the main chain of the compound is less than 3, the molar molecular volume +4n.

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

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

Inner layer:
Polyvinyl chloride (PVC) (“TS-1000R” manufactured by Tokuyama Sekisui Kogyo Co., Ltd.)

Outer layer:
Polyvinyl chloride (PVC) (“TS-1000R” manufactured by Tokuyama Sekisui Kogyo Co., Ltd.)
Mixture of polymethyl methacrylate and acrylic rubber (PMMA + acrylic rubber) (“IRH50” manufactured by Mitsubishi Rayon Co., Ltd.)
Polymethyl methacrylate (PMMA) ("VH" manufactured by Mitsubishi Rayon Co., Ltd.)
Acrylonitrile-EPDM-styrene copolymer (AES) ("UB700A" manufactured by A&L Japan)

Adhesive materials shown in Table 1 below were prepared as the first adhesive material and the second adhesive material. The thermoplastic resin in Table 1 is a chlorinated vinyl chloride resin (“HA-57K” manufactured by Tokuyama Sekisui Kogyo Co., Ltd.).

The following materials were prepared as connection target members.

TS socket ("TS50" manufactured by Sekisui Chemical Co., Ltd., socket length 63 mm, polyvinyl chloride (PVC) content: 90% by weight or more, content of components other than PVC: 10% by weight or less)

(Example 1)
(1) Fabrication of Multi-Layer Pipes In the configurations shown in Tables 3 and 4 below, multi-layer pipes were molded under the following extrusion conditions. A multilayer tube was obtained in which the outer surface of the inner layer was covered with the outer layer. PMMA+acrylic rubber was used as the material of the outer layer. The obtained multilayer tube had a length of 40 cm, an outer diameter of 60 mm, an inner layer thickness of 4.1 mm, and an outer layer thickness of 100 μm.

The ratio of the insertion length of the multilayer pipe to the insertable length defined by the member to be connected when the multilayer pipe is inserted into the member to be connected with a load of 100 N (insertion length of the multilayer pipe / defined by the member to be connected) It was confirmed that the insertable length) was 1/3 or more and 2/3 or less.

[Extrusion conditions]
Extruder: "SLM50" manufactured by Nagata Seisakusho Co., Ltd. (biaxial parallel direction extruder)
Sub-extruder: "OPEH-40" manufactured by Nagata Seisakusho (single-screw extruder)
Mold: Mold for pipes, for manufacturing multi-layered pipes with a nominal diameter of 50A Total output: 20 kg/h
Resin temperature: multilayer pipe body (inner layer) 190°C (temperature at mold entrance), coating layer (outer layer) 220°C (temperature at mold entrance)

(2) Fabrication of Piping (Multi-Layer Pipe Connector) The following steps were performed using the adhesive material F as the first adhesive material and the adhesive material B as the second adhesive material.

First step:
Adhesive material F was applied to the outer surface of one end of the multi-layered tube so as to reach the end of the multi-layered tube, and then adhesive material B was applied to the portion where adhesive material F was applied. The length of the first adhesive layer in the axial direction of the multilayer pipe (the length of the portion of the first adhesive layer located on the outer surface of the outer layer in the axial direction of the multilayer pipe) is 63 mm. there were.

Second step:
An adhesive material F was applied to the inner surface of one end of the connection target member so as to reach the end of the connection target member, and then an adhesive material B was applied to the portion where the adhesive material F was applied. Length of the second adhesive layer in the axial direction of the member to be connected (Regarding the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected) was 63 mm.

Connection between multilayer pipe and member to be connected (third step):
By inserting the multilayer pipe into the receptacle of the connection target member at 700 N and connecting, the connection target member is arranged on the outer surface side of the first adhesive layer, and the multilayer pipe is placed on the inner surface side of the second adhesive layer. By arranging, piping was produced.

(Example 2)
(1) Preparation of multilayer pipe A multilayer pipe was prepared in the same manner as in Example 1, except that PMMA was used as the material for the outer layer.

(2) Preparation of Piping (Multi-Layer Pipe Connector) The following steps were performed using the adhesive material H as the first adhesive material and the adhesive material B as the second adhesive material.

First step:
Adhesive material H was applied to the outer surface of one end of the multi-layered tube so as to reach the end of the multi-layered tube, and then adhesive material B was applied to the portion where adhesive material H was applied. The length of the first adhesive layer in the axial direction of the multilayer pipe (the length of the portion of the first adhesive layer located on the outer surface of the outer layer in the axial direction of the multilayer pipe) is 63 mm. there were.

Second step:
The adhesive material H was applied to the inner surface of one end of the connection target member so as to reach the end of the connection target member, and then the adhesive material B was applied to the portion where the adhesive material H was applied. Length of the second adhesive layer in the axial direction of the member to be connected (Regarding the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected) was 63 mm.

Connection between multilayer pipe and member to be connected (third step):
A multilayer pipe and a member to be connected were connected in the same manner as in Example 1 to prepare a pipe.

(Example 3)
(1) Preparation of multi-layer pipes Except for using a mixed material of PMMA + acrylic rubber and PVC (compounding ratio (weight ratio) of PMMA and PVC: PMMA + acrylic rubber: PVC = 4:1) as the material for the outer layer , a multi-layer pipe was produced in the same manner as in Example 1.

(2) Preparation of Piping (Multi-Layer Pipe Connector) The following steps were performed using the adhesive material E as the first adhesive material and the adhesive material B as the second adhesive material.

First step:
Adhesive material E was applied to the outer surface of one end of the multi-layered tube so as to reach the end of the multi-layered tube, and then adhesive material B was applied to the portion where adhesive material E was applied. The length of the first adhesive layer in the axial direction of the multilayer pipe (the length of the portion of the first adhesive layer located on the outer surface of the outer layer in the axial direction of the multilayer pipe) is 63 mm. there were.

Second step:
Adhesive material E was applied to the inner surface of one end of the member to be connected so as to reach the end of the member to be connected, and then adhesive material B was applied to the portion where adhesive material E was applied. Length of the second adhesive layer in the axial direction of the member to be connected (Regarding the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected) was 63 mm.

Connection between multilayer pipe and member to be connected (third step):
A multilayer pipe and a member to be connected were connected in the same manner as in Example 1 to prepare a pipe.

(Example 4)
(1) Preparation of multilayer pipe A multilayer pipe was prepared in the same manner as in Example 1.

(2) Fabrication of Piping (Multi-Layer Pipe Connector) The following steps were performed using the adhesive material E as the first adhesive material and the adhesive material A as the second adhesive material.

First step:
An adhesive material E was applied to the outer surface of one end of the multi-layered tube so as to reach the end of the multi-layered tube. The length of the first adhesive layer in the axial direction of the multilayer pipe (the length of the portion of the first adhesive layer located on the outer surface of the outer layer in the axial direction of the multilayer pipe) is 63 mm. there were.

Second step:
An adhesive material A was applied to the inner surface of one end of the member to be connected so as to reach the end of the member to be connected. Length of the second adhesive layer in the axial direction of the member to be connected (Regarding the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected) was 63 mm.

Connection between multilayer pipe and member to be connected (third step):
A multilayer pipe and a member to be connected were connected in the same manner as in Example 1 to prepare a pipe.

(Example 5)
(1) Preparation of multilayer pipe A multilayer pipe was prepared in the same manner as in Example 1.

(2) Fabrication of Piping (Multi-Layer Pipe Connector) The following steps were performed using the adhesive material E as the first adhesive material and the adhesive material A as the second adhesive material.

First step:
Adhesive material A was applied to the outer surface of one end of the multi-layered tube so as to reach the end of the multi-layered tube, and then adhesive material E was applied to the portion where adhesive material A was applied. The length of the first adhesive layer in the axial direction of the multilayer pipe (the length of the portion of the first adhesive layer located on the outer surface of the outer layer in the axial direction of the multilayer pipe) is 63 mm. there were.

Second step:
Adhesive material A was applied to the inner surface of one end of the member to be connected so as to reach the end of the member to be connected, and then adhesive material E was applied to the portion where adhesive material A was applied. Length of the second adhesive layer in the axial direction of the member to be connected (Regarding the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected) was 63 mm.

Connection between multilayer pipe and member to be connected (third step):
A multilayer pipe and a member to be connected were connected in the same manner as in Example 1 to prepare a pipe.

(Example 6)
(1) Preparation of multilayer pipe A multilayer pipe was prepared in the same manner as in Example 1.

(2) Preparation of Piping (Multi-Layer Pipe Connector) The following steps were performed using the adhesive material D as the first adhesive material and the adhesive material A as the second adhesive material.

First step:
Adhesive material A was applied to the outer surface of one end of the multi-layered tube so as to reach the end of the multi-layered tube, and then adhesive material D was applied to the portion where adhesive material A was applied. The length of the first adhesive layer in the axial direction of the multilayer pipe (the length of the portion of the first adhesive layer located on the outer surface of the outer layer in the axial direction of the multilayer pipe) is 63 mm. there were.

Second step:
Adhesive material A was applied to the inner surface of one end of the member to be connected so as to reach the end of the member to be connected, and then adhesive material D was applied to the portion where adhesive material A was applied. Length of the second adhesive layer in the axial direction of the member to be connected (Regarding the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected) was 63 mm.

Connection between multilayer pipe and member to be connected (third step):
A multilayer pipe and a member to be connected were connected in the same manner as in Example 1 to prepare a pipe.

(Example 7)
(1) Preparation of multilayer pipe A multilayer pipe was prepared in the same manner as in Example 1, except that AES was used as the material for the outer layer.

(2) Fabrication of Piping (Multi-Layer Pipe Connector) The following steps were performed using the adhesive material F as the first adhesive material and the adhesive material B as the second adhesive material.

First step:
Adhesive material F was applied to the outer surface of one end of the multi-layered tube so as to reach the end of the multi-layered tube, and then adhesive material B was applied to the portion where adhesive material F was applied. The length of the first adhesive layer in the axial direction of the multilayer pipe (the length of the portion of the first adhesive layer located on the outer surface of the outer layer in the axial direction of the multilayer pipe) is 63 mm. there were.

Second step:
An adhesive material F was applied to the inner surface of one end of the connection target member so as to reach the end of the connection target member, and then an adhesive material B was applied to the portion where the adhesive material F was applied. Length of the second adhesive layer in the axial direction of the member to be connected (Regarding the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected) was 63 mm.

Connection between multilayer pipe and member to be connected (third step):
A multilayer pipe and a member to be connected were connected in the same manner as in Example 1 to prepare a pipe.

(Example 8)
(1) Preparation of multilayer pipe A multilayer pipe was prepared in the same manner as in Example 1.

(2) Production of Piping (Multi-Layer Pipe Connector) The following steps were performed using the adhesive material F as the first adhesive material and the adhesive material G as the second adhesive material.

An adhesive material F was applied to the outer surface of one end of the multi-layered tube so as to reach the end of the multi-layered tube. The length of the first adhesive layer in the axial direction of the multilayer pipe (the length of the portion of the first adhesive layer located on the outer surface of the outer layer in the axial direction of the multilayer pipe) is 63 mm. there were.

Second step:
An adhesive material G was applied to the inner surface of one end of the member to be connected so as to reach the end of the member to be connected. Length of the second adhesive layer in the axial direction of the member to be connected (Regarding the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected) was 63 mm.

Connection between multilayer pipe and member to be connected (third step):
A multilayer pipe and a member to be connected were connected in the same manner as in Example 1 to prepare a pipe.

(Comparative example 1)
(1) Preparation of multilayer pipe A multilayer pipe was prepared in the same manner as in Example 1.

(2) Preparation of Piping (Multi-Layer Pipe Connector) The following steps were performed using only the adhesive material B, which is the second adhesive material.

First step:
Adhesive material B was applied to the outer surface of one end of the multi-layered tube so as to reach the end of the multi-layered tube. The length of the adhesive layer formed of the adhesive material B in the axial direction of the multilayer tube (for the portion of the adhesive layer formed of the adhesive material B located on the outer surface of the outer layer, ) was 63 mm.

Second step:
Adhesive material B was applied to the inner surface of one end of the member to be connected so as to reach the end of the member to be connected. Length of the second adhesive layer in the axial direction of the member to be connected (Regarding the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected) was 63 mm.

Connection between multilayer pipe and member to be connected (third step):
A multilayer pipe and a member to be connected were connected in the same manner as in Example 1 to prepare a pipe.

(Comparative example 2)
(1) Preparation of multi-layer pipes Except for using a mixed material of PMMA + acrylic rubber and PVC (compounding ratio (weight ratio) of PMMA and PVC: PMMA + acrylic rubber: PVC = 4:1) as the material for the outer layer , a multi-layer pipe was produced in the same manner as in Example 1.

(2) Preparation of Piping (Multi-Layer Pipe Connector) The following steps were performed using only the adhesive material A, which is the second adhesive material.

First step:
Adhesive material A was applied to the outer surface of one end of the multi-layered tube so as to reach the end of the multi-layered tube. The length of the adhesive layer formed of the adhesive material A in the axial direction of the multi-layer tube ) was 63 mm.

Second step:
An adhesive material A was applied to the inner surface of one end of the member to be connected so as to reach the end of the member to be connected. Length of the second adhesive layer in the axial direction of the member to be connected (Regarding the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected) was 63 mm.

Connection between multilayer pipe and member to be connected (third step):
A multilayer pipe and a member to be connected were connected in the same manner as in Example 1 to prepare a pipe.

(Comparative Example 3)
(1) Preparation of multilayer pipe A multilayer pipe was prepared in the same manner as in Example 1, except that PMMA was used as the material for the outer layer.

(2) Preparation of Piping (Multi-Layer Pipe Connector) The following steps were performed using only the adhesive material B, which is the second adhesive material.

First step:
Adhesive material B was applied to the outer surface of one end of the multi-layered tube so as to reach the end of the multi-layered tube. The length of the adhesive layer formed of the adhesive material B in the axial direction of the multilayer tube (for the portion of the adhesive layer formed of the adhesive material B located on the outer surface of the outer layer, ) was 63 mm.

Second step:
Adhesive material B was applied to the inner surface of one end of the member to be connected so as to reach the end of the member to be connected. Length of the second adhesive layer in the axial direction of the member to be connected (Regarding the portion of the second adhesive layer located on the inner surface of the member to be connected, the length of the portion in the axial direction of the member to be connected) was 63 mm.

Connection between multilayer pipe and member to be connected (third step):
A multilayer pipe and a member to be connected were connected in the same manner as in Example 1 to prepare a pipe.

(evaluation)
(1) Weight increase due to solvent From the obtained multi-layer tube, only the outer layer was cut out and roll-pressed at 195°C under the following roll-press conditions to obtain a sample of 2.5 cm x 5 cm x 1.5 mm. . A member to be connected was cut out and roll-pressed at 195° C. under the following roll-press conditions to obtain a sample of 2.5 cm×5 cm×1.5 mm. The weight of each sample obtained was measured. Next, each obtained sample was immersed in each solvent of acetone, THF, MEK, cyclohexanone, and dichloromethane at 25° C. for 10 minutes, and the weight of the sample after immersion was measured. After that, the sample was dried at 23° C. for 24 hours, and the weight of the dried sample was measured. The amount of weight increase due to the solvent was calculated by the following formula.

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

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

Table 2 shows the results.

(2) Connection Accuracy For the obtained piping, the insertion length of the multi-layer pipe with respect to the member to be connected was determined. From the calculated insertion length and the socket length (63 mm) of the member to be connected, the connection accuracy was determined according to the following criteria.

[Connection Accuracy Criteria]
○: The insertion length matches the socket length △: The insertion length is shorter than the socket length by 5 mm or less ×: The insertion length is shorter than the socket length by more than 5 mm

(3) Adhesion strength (60°C) (short-term connection reliability)
Only the outer layer was cut out from the obtained multi-layered tube and subjected to roll-pressing under the roll-pressing conditions used in (1) Evaluation of weight increase due to solvent to form a 2.5 cm x 7.5 cm x 3.00 mm thick tube. 1 specimen was obtained. The member to be connected was cut out and roll-pressed under the roll-press conditions used in (1) Evaluation of weight increase due to solvent to obtain a second test piece of 2.5 cm × 7.5 cm × 3.00 mm. rice field. 0.1 g of the adhesive material applied to the outer layer used in each example and each comparative example was applied to the surface of the first test piece, and used in each example and each comparative example on the surface of the second test piece 0.1 g of the adhesive material was applied to each member to be connected. The surface of the first test piece to which the adhesive material was applied and the surface of the second test piece to which the adhesive material was applied were superimposed and adhered with a load of 0.2 N. After drying for a while, a laminate was obtained. 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 under conditions of 60° C. and a tensile speed of 5 mm/min. As a tensile tester, Shimadzu Corporation's "desktop precision universal testing machine AGX-X" was used. Adhesive strength at 60° C. was determined by the following formula. Adhesion strength at 60° C. was determined according to the following criteria. In addition, the volatilization rate at 23°C was also determined.

Adhesion strength (MPa) = breaking load (N) / adhesion area (mm ² )

[Determination Criteria for Adhesion Strength (60°C)]
○: Adhesive strength is 10 MPa or more △: Adhesive strength is 5 MPa or more and less than 10 MPa ×: Adhesive strength is less than 5 MPa

(4) Connection reliability (water tightness test)
In the obtained pipe, the multi-layer pipe is connected to one side of the member to be connected. An adhesive material was applied to the inner surface of the other side of the connection object member of the obtained pipe in the same manner as in each example and each comparative example. Also, a second multilayer tube was prepared. After applying an adhesive material to the outer surface of this second multilayer pipe in the same manner as in each example and each comparative example, the pipe was connected to the second multilayer pipe. Thus, a piping sample was obtained in which the multilayer pipe, the member to be connected, and the second multilayer pipe were provided in this order. The tubing samples were allowed to stand at 23°C for 24 hours and 72 hours. After standing, a water pressure of 1.0 MPa (hoop stress 6.4 MPa) was applied to the pipe sample at 23° C. for 1 hour, and water leakage from the pipe sample was confirmed.

[Judgment Criteria for Water Tightness Test]
○: No water leakage △: Slight water leakage ×: Water leakage occurs

(5) Connection reliability (destructive test) (long-term connection reliability)
In the obtained pipe, the multi-layer pipe is connected to one side of the member to be connected. An adhesive material was applied to the inner surface of the other side of the connection object member of the obtained pipe in the same manner as in each example and each comparative example. Also, a second multilayer tube was prepared. After applying an adhesive material to the outer surface of this second multilayer pipe in the same manner as in each example and each comparative example, the pipe was connected to the second multilayer pipe. Thus, a piping sample was obtained in which the multilayer pipe, the member to be connected, and the second multilayer pipe were provided in this order. This piping sample was allowed to stand at 60° C. for 144 hours. After standing still, a water pressure of 1.0 MPa (hoop stress 6.4 MPa) was applied to the pipe sample at 40° C. or 60° C., and the time until the pipe sample was broken and water leakage occurred was measured.

[Criteria for Destructive Test]
○: Time until the pipe is destroyed and water leakage occurs 100 hours or more △: Time until the pipe is destroyed and water leakage occurs 50 hours or more and less than 100 hours ×: The pipe is destroyed, Less than 50 hours before water leakage occurs

(6) Comprehensive Judgment Comprehensive judgment was made according to the following criteria.

[Criteria for Comprehensive Judgment]
○○: All of the three evaluation items of connection accuracy, adhesive strength, and connection reliability were evaluated as ○.
○: Among the three evaluation items of connection accuracy, adhesive strength, and connection reliability, two evaluation items are ○ and one evaluation item has △ △: Connection accuracy, adhesive strength, and connection reliability Of the 3 evaluation items, 1 evaluation item is ○ and 2 evaluation items are △ ×: Does not correspond to ○○, ○, and △ criteria

The piping configuration and results are shown in Tables 3 and 4 below.

DESCRIPTION OF SYMBOLS 1... Multi-layer tube 1a... End 2... First adhesive layer 3... Member to be connected 4... Second adhesive layer 3a... End 5... Multi-layer tube connector 11... Inner layer 12... Outer layer

Claims (13)

A multilayer pipe connection method for connecting a multilayer pipe comprising a tubular inner layer and an outer layer disposed on the outer surface of the inner layer to a member to be connected, comprising:
A method for connecting multilayer pipes using a first adhesive material and a second adhesive material,
a first step of forming a first adhesive layer with the first adhesive material on the outer surface side of the outer layer of the multilayer pipe;
a second step of forming a second adhesive layer with the second adhesive material on the inner surface side of the member to be connected;
A step of connecting the multilayer pipe and the member to be connected by arranging the second adhesive layer on the outer surface side of the first adhesive layer,
The material of the inner layer contains one or more selected from the group consisting of polyvinyl chloride and polyvinylidene fluoride,
The material of the outer layer contains a resin having a nitrile group or a carbonyl group,
The material of the member to be connected includes one or more selected from the group consisting of polyvinyl chloride and polyvinylidene fluoride,
The first adhesive material and the second adhesive material are different adhesive materials (as a combination of the first adhesive material and the second adhesive material, the following 1) to 3) are all the same adhesive Excludes material combinations: 1) all solvent types in said first adhesive material and all solvent types in said second adhesive material, 2) said first adhesive material and said second adhesive. 3) the mixing weight ratio of the plurality of solvents in the first adhesive material and the mixing weight ratio of the plurality of solvents in the second adhesive material, when the materials contain a plurality of solvents of the same type; the total content of the solvent in 100% by weight of the adhesive material of 1 and the total content of the solvent in 100% by weight of the second adhesive material) ,
The first adhesive material reduces the weight of the outer layer after immersion by 1.25 to the weight of the outer layer before immersion when the outer layer is immersed in the first solvent at 25° C. for 10 minutes. comprising a first solvent that increases by a factor of more than
A method for connecting multilayer pipes, wherein the content of the first solvent is 45% by weight or more in 100% by weight of the first adhesive material. When the connection target member is immersed in the second solvent at 25 ° C. for 10 minutes, the second adhesive material is added to the connection target member after immersion relative to the weight of the connection target member before immersion. 2. The method of connecting multi-layer pipes according to claim 1, comprising a second solvent that increases the weight of the pipe by more than 1.10 times. A multilayer pipe connection method for connecting a multilayer pipe comprising a tubular inner layer and an outer layer disposed on the outer surface of the inner layer to a member to be connected, comprising:
A method for connecting multilayer pipes using a first adhesive material and a second adhesive material,
a first step of forming a first adhesive layer with the first adhesive material on the outer surface side of the outer layer of the multilayer pipe;
a second step of forming a second adhesive layer with the second adhesive material on the inner surface side of the member to be connected;
A step of connecting the multilayer pipe and the member to be connected by arranging the second adhesive layer on the outer surface side of the first adhesive layer,
The material of the inner layer contains one or more selected from the group consisting of polyvinyl chloride and polyvinylidene fluoride,
The material of the outer layer contains a resin having a nitrile group or a carbonyl group,
The material of the member to be connected includes one or more selected from the group consisting of polyvinyl chloride and polyvinylidene fluoride,
The first adhesive material and the second adhesive material are different adhesive materials (as a combination of the first adhesive material and the second adhesive material, the first adhesive material and the second adhesive material excluding the combination of adhesive materials with the same composition as the material),
The first adhesive material reduces the weight of the outer layer after immersion by 1.25 to the weight of the outer layer before immersion when the outer layer is immersed in the first solvent at 25° C. for 10 minutes. comprising a first solvent that increases by a factor of more than
When the connection target member is immersed in the second solvent at 25 ° C. for 10 minutes, the second adhesive material is added to the connection target member after immersion relative to the weight of the connection target member before immersion. a second solvent that increases the weight of the
A method for connecting multilayer pipes, wherein the content of the first solvent is 45% by weight or more in 100% by weight of the first adhesive material. 4. The method of connecting multilayer pipes according to claim 2, wherein the first solvent in the first adhesive material and the second solvent in the second adhesive material are different. the material of the outer layer includes the material of the member to be connected,
The method for connecting multilayer pipes according to any one of claims 1 to 4 , wherein the content of the material of the member to be connected is 90% by weight or less in 100% by weight of the material of the outer layer. The first adhesive material does not contain a thermoplastic resin or contains a thermoplastic resin, and the content of the thermoplastic resin is 0% by weight or more and 10% by weight or less in 100% by weight of the first adhesive material. 6. The method for connecting multilayer pipes according to any one of 1 to 5 . The method for connecting multi-layer pipes according to any one of claims 1 to 6 , wherein said second adhesive material contains 35% by weight or less of a thermoplastic resin based on 100% by weight of said second adhesive material. at least one of the first adhesive material and the second adhesive material comprises a thermoplastic resin;
The total content of the thermoplastic resin in 100% by weight of the first adhesive material and the content of the thermoplastic resin in 100% by weight of the second adhesive material is 10% by weight or more and 50% by weight. The method for connecting multi-layer pipes according to any one of claims 1 to 7 , comprising the following. In the first step, the first adhesive layer and the second adhesive layer are formed by the first adhesive material and the second adhesive material on the outer surface side of the outer layer of the multilayer pipe. death,
In the second step, the first adhesive layer and the second adhesive layer are formed on the inner surface side of the member to be connected using the first adhesive material and the second adhesive material. The method for connecting multilayer pipes according to any one of claims 1 to 8 . The multilayer according to any one of claims 1 to 9 , wherein the multilayer pipe and the member to be connected are connected such that the adhesion strength between the multilayer pipe and the member to be connected at 60°C is 10 MPa or more. How to connect pipes. The time until water leakage occurs is 100 hours or more when water is passed through the multi-layer pipe connector in which the multi-layer pipe and the member to be connected are connected at 40° C. and a hoop stress of 6.4 MPa. The method for connecting a multilayer pipe according to any one of claims 1 to 10 , wherein the multilayer pipe and the member to be connected are connected to each other. The time until water leakage occurs is 100 hours or more when water is passed through the multi-layer pipe connector in which the multi-layer pipe and the member to be connected are connected at 60° C. and a hoop stress of 6.4 MPa. The method for connecting a multilayer pipe according to any one of claims 1 to 11 , wherein the multilayer pipe and the member to be connected are connected to each other. The method for connecting multilayer pipes according to any one of claims 1 to 12 , wherein the absolute value of the difference between the SP value of the outer layer and the SP value of the member to be connected is 1.0 or less.

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