JP2008030471A - Layered type elastic tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a layered type elastic tube in which durability over repetition impression of an elastic tube and chemical resistance are improved certainly. <P>SOLUTION: The elastic tube is a layered type elastic tube which comprises the inside consisting of a fluoropolymer layer 20 and an elastic layer 10 formed in the outside of this fluoropolymer layer 20, wherein an intermediate layer 30 comprising a porosity fluororesin 32 and an elastic body 31 filling up thin holes of this porosity fluororesin 32 is formed between the fluoropolymer layer 20 and the elastic layer 10, the inside fluoropolymer layer 20 and the porosity fluororesin 32 of the intermediate layer 30 are bonded, and the outside elastic layer 10 and the elastic body 31 of the intermediate layer 30 are bonded. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an elastic tube having an inner surface made of a fluororesin, and preferably relates to an elastic tube that repeatedly receives pressure in the tube radial direction, more preferably an elastic tube used for a pinch valve or a roller pump, etc. As described above, the present invention relates to an elastic tube useful for controlling the flow of fluid in the hollow of the tube by the radial pressing.

  In the pinch valve, the flow of fluid (liquid or the like) is stopped by pressing the elastic tube in the radial direction, and the flow of fluid is started by releasing the pressure. In the roller pump, the elastic tube is pressed by a roller in the radial direction, and fluid (liquid or the like) is sent out by moving the roller in the axial direction of the tube while maintaining this pressed state. In these pinch valves and roller pumps, the structure of the flow path can be simplified as compared with general valves and pumps, and there is less possibility of contaminating the fluid. For this reason, it is often used in the fields of food and medical equipment, and in recent years, it is also used for feeding a photoresist when a semiconductor is produced.

  In general, silicone rubber is used for the elastic tube because of its excellent elasticity (for example, Patent Document 1). However, silicone rubber is inferior in chemical resistance compared to fluororesins and the like. Therefore, in the elastic tube of Patent Document 1, a highly corrosive fluid (a photoresist liquid, a liquid for operating a process machine, a highly corrosive liquid used in the fields of pharmaceutical, food, medical, chemistry, etc.) When it is circulated, the durability of the tube is greatly impaired.

  In order to improve the chemical resistance of the tube, a fluorine-based elastic tube in which the elastomer is changed from silicone rubber to fluorine-based elastomer is also known (Patent Document 2). However, a flexible fluorine-based elastomer that can be applied as an elastic tube has high tackiness. Therefore, for example, if the elastic tube is left pressed with a roller of a roller pump, the inner surfaces stick to each other and cannot be restored, and the tube may be blocked. Moreover, since the tackiness is high when used repeatedly, the inner surface of the tube is easily damaged, and the durability is inferior to that of the silicone elastic tube.

  Patent Document 3 discloses an elastic tube obtained by winding an ePTFE (stretched polytetrafluoroethylene) film impregnated with an elastomer (silicone elastomer, perfluoropolyether elastomer, etc.) and curing the elastomer. Yes. Tubes using silicone elastomer are sold under the name “STA-PURE” by Japan Gore-Tex Co., Ltd. Tubes using perfluoropolyether elastomer are sold under the name “CHEM-SURE”. Has been. Although these tubes have drastically improved durability due to the ePTFE membrane, since they use silicone elastomer or perfluoroelastomer, they inherently have the same problems as those of Patent Document 1 and Patent Document 2. ing. That is, when a silicone elastomer is used, the chemical resistance is poor, and when a perfluoropolyether elastomer is used, the inner surface is more easily damaged than when a silicone elastomer is used.

  In order to improve the chemical resistance of a tube using a silicone elastomer, it has also been proposed to protect the inner surface with a fluororesin layer (Patent Document 4, etc.). In order to improve the tackiness of the inner surface of the tube using a fluorine-based elastomer, it has also been proposed to protect the inner surface with a fluororesin layer (Patent Document 5 and the like). However, these multi-layered tubes have insufficient adhesion between the elastomer layer and the fluororesin layer on the inner surface. In particular, when repeated stress of compression release is applied in the radial direction of the tube, the stress is concentrated on the joint interface between the inner surface layer and the elastomer layer, and delamination occurs particularly at the bent portion called “teak portion”. Durability cannot be obtained.

Patent Document 6 discloses that a fluorine-containing polymer layer and a thermoplastic elastomer layer are bonded via an intermediate layer. This intermediate layer has a sea-island structure of a thermoplastic elastomer and a fluorine-containing polymer, and in the vicinity of the interface between the thermoplastic elastomer layer, the thermoplastic polymer forms a sea phase and the fluorine-containing polymer forms an island phase. In the vicinity of the interface with the fluorine-containing polymer layer, the fluorine-containing polymer forms a sea phase and the thermoplastic polymer forms an island phase. When such an intermediate layer is formed, the problem of delamination is considered to be improved. However, the intermediate layer of Patent Document 6 is a complex structure in which the sea and islands of the sea-island structure are reversed on the front and back of the layer. Such a complicated intermediate layer is formed by co-extruding the intermediate layer with the thermoplastic elastomer layer and the fluorine-containing polymer layer, and the co-extrusion conditions (setting temperature, extrusion amount, take-up speed, die structure, screw structure) It can be formed by adjusting. For example, when the intermediate layer is made of a polyester-based thermoplastic elastomer (TPEE) and an ethylene-tetrafluoroethylene copolymer (ETFE), the polymer temperature is 200 to 260 ° C. and the shear rate is 0 to 1000 sec ⁻¹ (condition 1). TPEE forms the sea phase, ETFE forms the island phase, ETFE forms the sea phase, and TPEE forms the island phase when the polymer temperature is 230 to 310 ° C. and the shear rate is 0 to 1000 sec ⁻¹ (condition 2). That is. However, in this method, the polymer temperature needs to be different between the inner side and the outer side of the intermediate layer, but the actual thickness of the intermediate layer is only about 0.1 mm (Example). It is highly questionable whether it is practically possible to vary the temperature between the two. In particular, since the polymer temperature range of 230 to 260 ° C. is included in both of the above conditions 1 and 2, it is unclear what phase structure it will be, and in order to make TPEE into the sea phase, the polymer temperature is 230 ° C. The polymer temperature must be 260 ° C. or higher in order to ensure that TPEE is in the island phase. It seems that it is virtually impossible to produce a temperature difference of 30 ° C. (= 260−230 ° C.) or more in only 0.1 mm. Even if it can be realized, it is thought that reproducibility is poor and it is extremely difficult to ensure quality. Furthermore, according to Patent Document 6, since it is necessary to adopt a complex structure in which the sea and islands of the sea-island structure are reversed on the front and back of the layer, the combinations of elastomers and fluoropolymers that can be used are practically very limited. It must be a thing. Furthermore, the elastomer is heated for a long time due to co-extrusion. Therefore, the elastomer is thermally deteriorated and the elasticity is also lowered.

Patent Document 7 discloses that an elastic layer in which an elastic body is filled in the pores of a porous fluororesin film is laminated on a release layer made of a fluororesin film. However, this patent document 7 relates to a toner fixing member. The elastic layer is directly laminated on the fluororesin film.
JP 2000-179753 A (Claims) Japanese Utility Model Publication No.59-41687 (Utility Model Registration Request) JP-T-2002-502735 (Claims, paragraphs 0026, 0037, 0073) Japanese Utility Model Publication No. 4-47185 (Scope of Claim for Utility Model Registration) JP 2001-193659 A (Claims) JP-A-9-131833 (Claims, paragraphs 0038 and 0042) Japanese Patent Laying-Open No. 2005-257762 (Claims)

  The present invention has been made paying attention to the above-described circumstances, and an object thereof is to provide an elastic tube that can reliably improve durability against repeated pressing and chemical resistance.

  As a result of intensive studies to solve the above problems, the present inventor has interposed an intermediate layer in which the pores of the porous fluororesin are filled with an elastic body between the inner fluororesin layer and the outer elastic layer. Inserting the inner fluororesin layer and the intermediate porous fluororesin, and joining the outer elastic layer and the intermediate elastic body, the inner fluororesin layer and the outer elastic layer It has been found that the adhesion between the two can be remarkably improved, and the durability against repeated pressing and the chemical resistance can be reliably improved, and the present invention has been completed.

That is, the laminated elastic tube according to the present invention is
The inner surface (inner layer) is composed of a fluororesin layer,
An elastic layer (outer layer) is formed outside the fluororesin layer,
Between the fluororesin layer (inner layer) and the elastic layer (outer layer), it is composed of a porous fluororesin (porous polytetrafluoroethylene, etc.) and an elastic body filling the pores of the porous fluororesin. An intermediate layer is formed,
The inner fluororesin layer and the intermediate porous fluororesin are joined (particularly heat-sealed),
The gist is that the elastic layer of the outer layer and the elastic body of the intermediate layer are joined.

  The fluororesin layer on the inner surface is preferably a tube around which a fluororesin film is wound. The fluororesin layer is preferably stretched in a direction perpendicular to the length direction of the tube. A particularly preferred fluororesin layer is a fully stretched fluororesin layer (particularly a fully stretched polytetrafluoroethylene layer). The fluororesin layer on the inner surface may be formed from a meltable fluororesin (PFA, FEP, PVDF, THV, EFEP, etc.).

  The fluororesin layer on the inner surface may be formed by laminating two or more fluororesins. For example, two or more kinds of fluororesins may each be a tube, and the tubes may be laminated in order from the inside. Two or more kinds of fluororesins may be laminated in a planar shape, and this planar laminate may be wound into a tube shape. It is preferable that one of the two or more fluororesins is a fully stretched fluororesin, and the other one is a meltable fluororesin (PFA, FEP, PVDF, THV, EFEP, etc.). The meltable fluororesin is desirably disposed on the outermost side of the fluororesin layer on the inner surface.

As the elastic body of the intermediate layer or the outer layer, silicone elastomer, fluorine elastomer, fluorosilicone elastomer, or the like can be used. The elastic material of the intermediate layer and the outer layer is a polyester-based thermoplastic elastomer, a polyurethane-based thermoplastic elastomer, a polyolefin-based thermoplastic elastomer, a styrene-based block copolymer elastomer, a thermoplastic vulcanized elastomer, a polyamide-based thermoplastic elastomer, or the like. May be. In the present invention, it is recommended to use the same resin for the elastic body of the intermediate layer and the elastic body of the outer layer. The storage elastic modulus E ′ of the elastic layer (outer layer) is, for example, about 1 × 10 ² to 1 × 10 ⁸ Pa. The elastic layer includes (1) a first layer made of an elastic body, (2) a porous polytetrafluoroethylene film, and a second body made of an elastic body filling the pores of the porous polytetrafluoroethylene film. You may have the spiral laminated structure with which the layer of this was overlapped. The ratio of the thickness of the first layer to the thickness of the second layer (first layer / second layer) is, for example, about 6.5 / 1 or less.

The thickness of the laminated elastic tube of the present invention is, for example, as follows.
Inner layer (fluororesin layer): 1 to 200 μm
Intermediate layer: 10 to 2000 μm
Outer layer (elastic layer): 0.15 to 80 mm
The thickness of the elastic layer is, for example, about 10 to 200% with respect to the inner diameter of the laminated elastic tube.

  A wear-resistant layer (such as a polytetrafluoroethylene tube) may be formed outside the elastic layer.

In the laminated elastic tube of the present invention, a tube made of a fluororesin layer (inner layer) is coated with a porous fluororesin, and these are heat-sealed,
Filling the pores of the porous fluororesin from the porous fluororesin side with a liquid elastic material,
After filling, it can be produced by forming a three-dimensional network structure and making the elastic material into an elastic body. Preferably, a three-dimensional network structure is formed after forming a layer containing an elastic material on the outside of the porous fluororesin.

  The laminated elastic tube of the present invention is useful for a pinch valve or a roller pump.

  According to the present invention, since the intermediate layer in which the pores of the porous fluororesin are filled with an elastic body is interposed between the inner fluororesin layer and the outer elastic layer, the inner fluororesin layer and the outer The adhesion between the elastic layer and the elastic layer can be remarkably improved, and the durability against repeated pressing and the chemical resistance can be reliably improved.

  Hereinafter, the present invention will be described in more detail with reference to the drawings as appropriate. However, the present invention is not limited to the illustrated examples, and appropriate modifications are made within a range that can be adapted to the purpose described above and below. It is also possible to carry out and they are all included in the technical scope of the present invention.

  FIG. 1 is a schematic cross-sectional view showing an example of a laminated elastic tube of the present invention, and FIG. 2 is an enlarged view of a main part of this cross-sectional view. As shown in FIG. 1, the laminated elastic tube of the present invention has an inner surface composed of a fluororesin layer 20, and an elastic layer 10 is formed on the outer side of the fluororesin layer 20. An intermediate layer 30 is formed between the elastic layer 10 and the elastic layer 10. The intermediate layer 30 includes a porous fluororesin 32 and an elastic body 31 that fills the pores of the porous fluororesin. The inner fluororesin layer 20 and the porous fluororesin 32 of the intermediate layer 30 are joined, and the outer elastic layer 10 and the elastic body 31 of the intermediate layer 30 are joined.

  When this intermediate layer 30 is employed, the adhesion between the fluororesin layer 20 and the elastic layer 10 can be dramatically improved. In the sea-island structure, even if the sea part is a continuous structure, the island part becomes an independent structure, whereas in the intermediate layer 30 of the present invention in which the elastic body 31 is filled in the pores of the porous fluororesin 32, the porous part is porous. Since both the porous fluororesin 32 and the elastic body 31 have a continuous structure, the area of the continuous interface between the elastic body and the fluororesin increases dramatically. This is thought to have led to a dramatic improvement in adhesion. In addition, the laminated elastic tube can be manufactured without thermally degrading the elastic layer 10 and the elastic body 31, and the elasticity can be reliably ensured.

Hereinafter, each configuration will be described in more detail.
1: Elastic layer (outer layer) 10
The elasticity of the laminated elastic tube of the present invention is achieved by an elastic layer 10 including an elastic body 11 (hereinafter also referred to as an outer layer). Examples of the elastic body 11 include silicone elastomers, fluorine elastomers (crosslinked fluorine elastomers, fluorine thermoplastic elastomers, etc.), fluorosilicone elastomers, polyester elastomers, polyurethane elastomers (polyurethane rubber, polyurethane thermoplastic elastomers). Etc.), polyolefin elastomer, styrene elastomer, polyamide elastomer, fluorophosphazene elastomer, phosphazene rubber, nitrile rubber, styrene-butadiene rubber (SBR), chloroprene rubber and the like. These elastic bodies 11 can be used individually or in combination of 2 or more types.

  The elastic body 11 may be a crosslinkable elastomer (for example, a crosslinkable elastomer corresponding to a silicone elastomer, a fluorine elastomer, a fluorosilicone elastomer, etc.), and is a thermoplastic elastomer (preferably a polyester thermoplastic elastomer (preferably a polyester thermoplastic elastomer). Especially, thermoplastic polyester elastomer (COPE), polyurethane thermoplastic elastomer (TPU), polyolefin thermoplastic elastomer (TPO), fluoroplastic elastomer, styrene block Copolymer elastomers (Styrenic Block Copolymer Elastomers: SBC), thermoplastic vulcanized elastomers (Copolyester Thermoplastic Elastomers: COPE), polyamide thermoplastic elastomers (Polyam) ide Thermoplastic Elastomers (PEBA), etc .; preferably COPE, TPU, TPO, SBC, COPE, PEBA). The cross-linked elastomer is excellent in that the use temperature of the laminated elastic tube can be increased. Thermoplastic elastomers are excellent in that they can be continuously produced by extrusion and have high elasticity.

  Particularly preferred elastic bodies 11 are silicone elastomers, fluorine elastomers, fluorosilicone elastomers, and the like. These particularly preferable elastic bodies 11 are excellent in any of heat resistance, chemical resistance, and durability against repeated pressing. For example, silicone elastomers are particularly excellent in mechanical strength, elasticity sustainability, shape recovery when releasing compressive stress, and the like. The fluorine-based elastomer is excellent in chemical resistance. Fluorosilicone elastomers exhibit intermediate properties between both silicone elastomers and fluorine elastomers.

  The silicone elastomer has a crosslinked organopolysiloxane in which a methyl group is bonded to silicon (such as methyl silicone rubber), and a crosslinked organopolysiloxane in which an aromatic hydrocarbon is bonded to silicon (phenyl silicone rubber). Etc.) and silicone rubber.

  Examples of the fluorine elastomer include a crosslinked polymer having fluoromethylene in the main chain, a fluorine thermoplastic elastomer, and the like. The cross-linked body includes FKM (binary FKM, ternary FKM, perfluorovinyl ether-containing FKM), FFKM, TFE-Pr fluororubber, TFE-Pr-VdF fluororubber, and fluorinated polyether skeleton. Cross-linked rubber (liquid fluororubber etc.) is included (see the following formula). Liquid fluororubber can be obtained from Shin-Etsu Chemical Co., Ltd. as “SIFEL” (trade name).

  Fluorosilicone elastomers include fluorosilicone rubbers such as crosslinked organopolysiloxanes in which a fluoroalkyl group is bonded to silicon. A cross-linked polysiloxane bonded with a fluoroalkyl group (such as FMVQ; see the following formula) corresponds to a fluorosilicone rubber.

  The cross-linked elastomer cross-links or the hard segments of the thermoplastic elastomer interact with each other to finally cure (not limited to cross-linking, which means that a wide three-dimensional network structure is formed. As long as the same applies, the elastic body 11 does not have to be cured at the raw material stage. The elastic material 11 may be solid (kneadability) or liquid. The elastic body 11 obtained from the solid (kneadability) elastic body material 11 is particularly excellent in mechanical strength, shape recovery property when releasing compressive stress, and the like. As the solid elastic material 11, a millable (kneaded) silicone rubber can be used. Millable silicone rubber is a rubber that contains a high-viscosity silicone rubber compound and a curing agent (vulcanizing agent) and is cured by heating. It is a heat-curing silicone rubber (HCR (Heat Cured Rubber), HVR (Heat Vulcanizing). Rubber) and HTV (High Temperature Vulcanizing) rubber).

  On the other hand, the liquid elastic material 11 is useful when the elastic body 11 is reinforced with another material, as will be described later. For example, the elastic body 11 may be reinforced by filling the pores of the porous body. If the liquid elastic material 11 is used, the pores of the porous body can be easily impregnated.

  The liquid elastic material 11 means an elastic material 11 that is liquid before curing and exhibits elasticity after curing. For example, liquid silicone elastomer (liquid silicone rubber, etc.), liquid fluorine And elastomers (such as liquid fluororubber), liquid fluorosilicone elastomers (such as liquid fluorosilicone rubber), and thermoplastic elastomers that are liquid (fluidized) by heating or dissolving with a solvent.

  Liquid silicone rubbers, liquid fluororubbers, liquid fluorosilicone rubbers, etc. are classified into a condensation reaction type that crosslinks with moisture in the air, an addition reaction type that crosslinks with a noble metal catalyst, and a thermosetting type that crosslinks by heating. In consideration of mass production and the like, addition reaction type and heat curing type are preferable. The viscosity (25 ° C.) before curing (crosslinking) is, for example, about 1000 poise or less, preferably about 200 poise or less. The lower the viscosity, the easier the porous material is impregnated with the elastic material 11 as will be described later. Such a liquid silicone rubber can be obtained from Shin-Etsu Chemical Co., Ltd. as “RTV rubber for electric / electronic / general industrial use”, for example. The liquid fluororubber can be obtained as “SIFEL” (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) as described above. The liquid fluorosilicone rubber can be obtained from Shin-Etsu Chemical Co., Ltd. as “oil resistant / solvent resistant fluorosilicone”, for example.

  The elastic body 11 of the elastic layer 10 may be used in combination with other materials. For example, if cloth, organic fiber, inorganic fiber, carbon, metal fine particles, inorganic powder, etc. are mixed in the elastic body 11, the elastic layer 10 can be improved in terms of mechanical strength, electrical characteristics, thermal conductivity, and the like. it can. By improving the mechanical strength, when the elastic tube of the present invention is used for a pinch valve or a roller pump, the elastic layer 10 can be more highly prevented from being damaged by the pressing force. If the elastic layer 10 is improved in terms of electrical characteristics, thermal conductivity, etc., the antistatic property of the obtained laminated elastic tube is improved, and the laminated elastic tube can be easily heated.

  When increasing the mechanical strength of the elastic layer 10, it is most desirable to fill the pores of the porous body with the elastic body 11. By supporting the elastic body 11 with a porous body, the mechanical strength of the elastic layer 10 can be increased without impairing elasticity. A particularly preferable reinforced elastic layer 10 is a spiral laminate in which a first layer 12 made of an elastic body 11 and a layer 13 (second layer) of a porous film filled with pores by the elastic body 11 are overlapped. It has a structure (hereinafter referred to as a spiral elastic layer 10). FIG. 3 is a schematic sectional view showing an example of the spiral elastic layer 10. The spiral elastic layer 10 can be produced by winding a porous film impregnated (coated) inside and on the surface of a porous film as described in JP-T-2002-502735. The mechanical strength of 10 can be dramatically increased. In addition, the spiral elastic layer 10 is remarkably excellent in terms of shape restoration property when releasing the compressive stress.

  The porous film constituting the spiral elastic layer 10 is not particularly limited as long as it is flexible and does not impair the elasticity of the elastic body 11, and may be the same as the porous fluororesin 32 constituting the intermediate layer 30. The porous film (for example, polyimide porous film) formed from resin other than a fluororesin may be sufficient. Preferred porous films are porous films excellent in heat resistance (porous fluororesin film, polyimide porous film, etc.), and particularly preferred porous films are porous bodies excellent in chemical resistance, heat resistance, flexibility and the like. (Porous fluororesin film, especially porous polytetrafluoroethylene film). An elastic tube composed of a spiral elastic layer 10 in which the elastic body 11 is silicone rubber and the porous film is a porous polytetrafluoroethylene film can be obtained from Japan Gore-Tex Co., Ltd. under the trade name “STA-PURE”. . An elastic tube comprising a spiral elastic layer 10 in which the elastic body 11 is fluororubber and the porous film is a porous polytetrafluoroethylene film is obtained from Japan Gore-Tex Co., Ltd. under the trade name “CHEM-SURE”. it can.

  Thickness ratio (first layer / second layer) of the first layer 12 (elastic body) and the second layer 13 (porous film with pores filled with an elastic body) of the spiral elastic layer 10 ) Is, for example, about 6.5 / 1 or less. As the thickness ratio decreases, the strength of the elastic layer 10 increases. A preferred thickness ratio (first layer / second layer) is about 5/1 or less, particularly about 3/1 or less. On the other hand, the lower limit of the thickness ratio (first layer / second layer) is not particularly limited, and the elastic layer 10 may be substantially composed of the second layer 13 alone. The thickness ratio is the thickness of the elastic body formed on the surface of the porous film when the spiral elastic layer is produced by winding the porous film impregnated (coated) with the elastic body. It can be adjusted by controlling.

  The higher the tensile strength (JIS K 6249) of the elastic layer 10 is, the higher the durability of the tube is improved. For example, 0.1 MPa or more, preferably 3 MPa or more, more preferably 7 MPa or more (for example, about 7 MPa to 75 MPa). ).

  The elastic body 11 constituting the elastic layer 10 is also preferably high in mechanical strength. When the mechanical strength of the elastic body 11 is high, not only can the mechanical strength of the elastic layer 10 be increased to increase the durability of the elastic layer 10, but also the bondability with the intermediate layer 30 can be improved. The tensile strength (JIS K 6249) of the elastic body 11 can be set, for example, from about 0.1 to 75 MPa, preferably from about 0.3 to 75 MPa.

The storage elastic modulus E ′ (temperature 20 ° C., frequency 1 Hz, compression method) of the elastic layer 10 is, for example, about 1 × 10 ² to 1 × 10 ⁸ Pa. When the storage elastic modulus is too low, the shape restoring property at the time of releasing the compressive stress becomes poor. On the other hand, when the storage elastic modulus is too high, it becomes difficult to crush the tube, and it becomes difficult to use it for a pinch valve or a roller pump. A preferable storage elastic modulus E ′ is about 1 × 10 ⁴ to 1 × 10 ⁸ Pa, particularly about 1 × 10 ^{5 to} 5 × 10 ⁷ Pa.

  The storage elastic modulus E ′ by the compression method is “value obtained by dividing the normal stress component in the same phase as the normal strain by the strain amount” described in Japanese Industrial Standard (JIS) K6200 Term No. 6211. Means. The storage elastic modulus E ′ can be measured by using, for example, a dynamic viscoelasticity measuring device “DMS6100” (manufactured by SII Nanotechnology).

  The thickness of the elastic layer 10 (outer layer) is, for example, about 10 to 200%, preferably about 20 to 150%, more preferably 25 to the inner diameter of the laminated elastic tube constituted by the elastic layer 10. It is about 125%. The thickness of the elastic layer 10 (outer layer) is, for example, about 0.15 to 80 mm, preferably about 0.3 to 60 mm, and more preferably about 0.4 to 50 mm. If the elastic layer 10 is too thin, when the tube is used for a pinch valve or a roller pump, the tube may not withstand the internal pressure of the fluid in the tube and may burst. Further, the shape recoverability when releasing the compressive stress (pressing force) becomes insufficient. Conversely, when the elastic layer 10 is too thick, it becomes difficult to close the tube by pressing.

2: Fluororesin layer (inner layer) 20
The laminated elastic tube of the present invention includes a fluororesin layer 20 in addition to the elastic layer 10. The fluororesin layer 20 is formed on the inner side of the elastic layer 10 and constitutes the inner surface of the tube. Hereinafter, the fluororesin layer 20 may be referred to as an inner layer. The fluororesin layer 20 on the inner surface is excellent in chemical resistance and has low tack (adhesiveness). When the elastic body 11 of the elastic layer 10 is inferior in chemical resistance such as silicone rubber, the chemical resistance of the tube itself is generally lowered. However, if the inner surface is made of the fluororesin layer 20 as in the present invention, The fluororesin layer 20 on the inner surface can be used as a barrier layer, and the chemical resistance of the tube can be improved. Furthermore, it is possible to prevent the fluid from adhering to the inner surface of the tube. In addition, when the elastic body 11 of the elastic layer 10 has high tackiness (adhesiveness) such as a fluorine-based elastomer, generally, as described above, the inner surfaces stick to each other and the tube is closed or the tube inner surface is damaged. However, if the inner surface is made of the fluororesin layer 20 as in the present invention, these problems can be reduced. Furthermore, elution and swelling of the tube material can be prevented.

The fluororesin used for the inner layer 20 has a low tack (adhesiveness). In addition, it has excellent chemical resistance, for example, durability against acids, alkalis, organic solvents, and the like. Therefore, for example, it is possible to distribute a fluid such as a photoresist liquid, a liquid for operating a process machine, a highly corrosive liquid used in fields such as pharmaceuticals, food, medicine, and chemistry. . As such a fluororesin, for example, non-meltable (melt viscosity (for example, viscosity at 340 ° C.) of 10 ¹⁰ Pa · s or more) fluororesin (polytetrafluoroethylene (PTFE) etc.), meltability ( Fluororesin (tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP) having a melt viscosity (for example, viscosity at 340 ° C.) of less than 10 ¹⁰ Pa · s) ), Ethylene-tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride Original copolymer (THV), EFE (“Neoflon EFEP” (trade name) manufactured by Daikin Industries, Ltd.), etc. The PTFE includes a relatively small amount of tetrafluoroethylene (for example, 1% by mass or less based on tetrafluoroethylene). Comonomer (hexafluoropropylene (HFP), perfluoropropyl vinyl ether (PPVE), perfluoroethyl vinyl ether (PEVE), chlorotrifluoroethylene (CTFE), perfluoroalkyl Modified PTFE copolymerized with ethylene, etc. From the viewpoint of adhesiveness with other layers, meltable fluororesins (particularly PFA, FEP, PVDF, THV, EFEP, etc.) are excellent and resistant. PTFE is excellent from the viewpoint of chemical properties and heat resistance. E is also excellent in that a thin film can be formed by stretching, and when the porous fluororesin 32 of the intermediate layer 30 is PTFE, it is recommended that the fluororesin of the inner layer 20 is also PTFE. When both the intermediate layer 30 and the intermediate layer 30 are formed of PTFE, the inner layer 20 and the intermediate layer 30 can be easily heat-sealed.

  As said fluororesin, 1 type may be used and 2 or more types may be used. First, the inner layer 20 will be described in more detail on the assumption that one type of fluororesin is used, and later, a change place when two or more types of fluororesin are used will be described.

  The fluororesin of the inner layer 20 is usually a solid (fully-dense fluororesin), but may be a porous body (porous fluororesin). The porous body can be used when the elastic body 31 of the intermediate layer 30 has excellent chemical resistance such as a fluorine-based elastomer.

  The solid fluororesin means a fluororesin having substantially no pores, and the porosity is, for example, less than 10%, preferably 5% or less, more preferably 1% or less, particularly 0%. . The solid fluororesin can usually be obtained by extrusion molding in the same manner as a general resin film, and then stretched as necessary, but solid PTFE is difficult to obtain in the same manner as a general resin film. It is. Solid PTFE can be obtained, for example, by scraping from non-porous sintered PTFE (generally referred to as skived PTFE), or by densifying a porous fluororesin (ePTFE) described later by compression or the like. Can be obtained (referred to as densified PTFE). Details of the method for producing densified PTFE are described in JP-A-2002-275280. A fluororesin having both a solid structure and a stretched structure may be hereinafter referred to as a fully-dense expanded fluororesin.

  The porous fluororesin may be a fluororesin obtained by molding a mixture of a fluororesin powder and a solvent-soluble fine powder and then eluting the soluble fine powder with a solvent, but is preferably obtained by stretching. It is porous PTFE (also referred to as expanded porous polytetrafluoroethylene (ePTFE)). ePTFE is obtained by mixing and molding PTFE fine powder and a molding aid, removing the molding aid, stretching at a high temperature and high speed, and further firing as necessary. This ePTFE may be uniaxially stretched, but is preferably biaxially stretched. Microscopically, uniaxially stretched PTFE has thin island-like nodes (folded crystals) that are substantially perpendicular to the stretch direction, and interdigital fibrils that connect the nodes (the folded crystals are unwound by stretching). A microscopic feature is that the drawn linear molecular bundle) is oriented in the stretching direction. In addition, biaxially stretched PTFE has a spider web-like fibrous structure in which fibrils spread radially, nodes connecting fibrils are scattered in islands, and there are many spaces defined by fibrils and nodes. Has microscopic features. The porosity of the porous fluororesin can be appropriately set according to the amount of soluble fine particles, the draw ratio, and the like. For example, the porosity is 10% or more, and may be 30% or more. The upper limit of the porosity is not particularly limited, but is, for example, about 95% or less, preferably about 85% or less.

The porosity is the apparent density ρ ₁ of the porous fluororesin (unit: g / cm ³ , measured according to JIS K 6885) and the original density of the fluororesin when not porous (true density) ) Ρ ₂ (2.2 g / cm ^{3 in} the case of PTFE) is a value calculated based on the following formula.
Porosity (%) = (ρ ₂ −ρ ₁ ) / ρ ₂ × 100

  Of the various fluororesins, stretched fluororesins (solid stretched fluororesin, stretched porous fluororesin, etc .; hereinafter, these may be collectively referred to as expanded fluororesin), particularly biaxial stretching Fluorine resin is preferred. The inner layer 20 can be strengthened by stretching.

  Although the extending | stretching direction is not specifically limited, It is preferable to extend | stretch in the direction (circumferential direction) orthogonal to the longitudinal direction of a tube. If the tube is stretched in the circumferential direction, it is possible to reduce a phenomenon (longitudinal crack) in which the tube is split in the longitudinal direction when the tube is repeatedly pressed.

  The most preferred fluororesin is a fully stretched fluororesin. The fully-stretched fluororesin is excellent in all of barrier properties against chemicals, slidability, and mechanical strength. In particular, when a densification treatment such as compression is performed, both the effect of improving the strength in the surface direction by stretching and the improvement of the strength in the thickness direction by densification are exhibited, and the mechanical strength of the inner layer 20 is remarkably increased. it can. Moreover, it is excellent also in the softness | flexibility, and even if it receives repeated press, it becomes difficult to produce peeling between this inner layer 20 and the intermediate | middle layer 30. FIG. Furthermore, according to the fully-stretched fluororesin, a thin film made of the fluororesin can be easily obtained, which is advantageous for producing a wound film described later.

  The form of the inner fluororesin layer 20 is not particularly limited, and a wound film obtained by winding a fluororesin film, an extruded tube obtained by extruding the fluororesin into a tube shape, and the inner surface of the tube molded body Any of coating layers obtained by coating a fluororesin-containing liquid on the surface may be used. Preferred forms are wound films, such as wound films and extruded tubes. According to the wound film, an inner layer having high mechanical strength can be formed, and it is easy to match the stretching direction of the fluororesin with the circumferential direction of the tube.

In addition, in a wound film, you may adhere | attach the film laminated | wrapped and laminated | stacked suitably. For example, the films may be bonded with an adhesive via a primer or the like, or the films may be heat-sealed. Preferably, the films are heat-sealed. If heat-sealing, the film layers can be bonded extremely firmly. In general, a fluororesin has a small intermolecular cohesive force and has a high molecular weight in order to ensure practical mechanical strength. For example, the molecular weight of PTFE is about 5 to 8 million according to an indirect measurement method such as an isop method. Even when such a high molecular weight fluororesin is heated to the melting point or higher, the viscosity is high (for example, the viscosity when PTFE is heated to the melting point or higher is about 10 ¹⁰ to 10 ¹² Pa · s). Melt molding is considered difficult. On the other hand, it is known that when the fluororesin films are pressurized at a temperature equal to or higher than the melting point of the fluororesin (and under conditions (temperature, time) that do not cause thermal decomposition), the fluororesin films are fused. . The interlayer adhesive force obtained by this heat fusion is strong, and an equivalent or higher adhesive force can be obtained as compared with the case where the fluororesin films are bonded to each other with an adhesive via a primer or the like. When it is difficult to heat-seal the fluororesin films, a melt-stable fluororesin film or a fluororesin dispersion can be heat-sealed between the films. Note that the melting point and thermal decomposition conditions (temperature, time) of the fluororesin differ depending on the type, grade, and processing conditions (processing environment, etc.) of the fluororesin, so DSC (differential scanning calorimeter) and TG (thermogravimetric analysis) It is desirable to grasp in advance using a total).

  Moreover, when the inner layer 20 is a wound film, you may perform the process (taper process) which inclines the corner | angular part of a winding end (an inner surface side edge part, an outer surface side edge part). If the inner surface side end is tapered, adverse effects on the fluid in the tube can be reduced. Moreover, if the outer surface side end portion is tapered, the adhesion between the inner layer 20 and the intermediate layer 30 can be improved. In order to taper, for example, a heating plate may be pressed against the winding end. Furthermore, for the same purpose, the end (end line) of the winding end may be inclined with respect to the tube center axis, and the film thickness is sufficiently thin (for example, about 0.1 to 30 μm, preferably about 0.1 μm). It may be about 5 to 10 μm, more preferably about 1 to 5 μm.

  Furthermore, surface treatment such as corona discharge treatment, excimer laser treatment, sandblast treatment, etching treatment with metallic sodium, liquid ammonium, or the like may be performed on one or both surfaces of the film. By performing these surface treatments, the films can be bonded more firmly. The outer surface of the fluororesin layer 20 may be subjected to the same surface treatment for the same purpose.

  As described above, the inner layer 20 may be formed of two or more (for example, about 2 to 4 types, particularly 2 types) fluororesins. Functions (chemical resistance, adhesiveness, etc.) can be shared among a plurality of fluororesins so that excellent functions can be exhibited as a whole. For example, a combination of a fluororesin with particularly excellent chemical resistance and mechanical strength (such as fully-stretched fluororesin) and a fluororesin with excellent adhesion (such as a meltable fluororesin) can provide chemical resistance and mechanical strength. However, a particularly excellent fluororesin can be firmly bonded to the intermediate layer 30.

  When the inner layer 20 is formed of two or more kinds of fluororesins, the respective fluororesins may be formed into a tube shape, and two or more kinds of tubes (fluororesin) may be laminated in order from the inside. Two or more kinds of fluororesins may be laminated in a planar shape, and the planar laminate may be wound once or more (preferably a plurality of times) to form a tube. Since the latter can arrange | position two or more types of fluororesins without bias, the performance of the inner layer 20 as a whole can be further improved. Regardless of the former or the latter, it is recommended that the outermost side of the inner layer 20 be made of a meltable fluororesin. This is because adhesion with the intermediate layer 30 is enhanced.

  The thickness of the fluororesin layer 20 on the inner surface is, for example, about 1 to 200 μm, preferably about 5 to 100 μm, and more preferably about 5 to 40 μm. If the inner layer 20 is too thin, the mechanical strength decreases. Therefore, it becomes difficult to improve the chemical barrier property and the slidability of the tube inner surface. On the other hand, if the inner layer 20 is too thick, the entire tube becomes hard. Therefore, the shape recoverability when the compressive stress (pressing force) is released tends to be insufficient. In addition, defects such as cracks are likely to occur due to repeated pressing.

  The fluororesin layer 20 on the inner surface may contain carbon, metal powder, or the like for imparting conductivity or improving thermal conductivity.

3: Intermediate layer 30
A feature of the laminated elastic tube of the present invention is that an intermediate layer 30 is formed between the fluororesin layer 20 (inner layer) and the elastic layer 10 (outer layer). The intermediate layer 30 includes a porous fluororesin 32 and an elastic body 31 that fills the pores of the porous fluororesin 32, and includes an inner fluororesin layer 20 and a porous fluorine of the intermediate layer 30. The resin 32 is joined. Further, the elastic layer 10 of the outer layer and the elastic body 31 of the intermediate layer 30 are joined. By forming such an intermediate layer 30, the peeling force acting between the inner layer 20 and the outer layer 10 can be buffered by the pressing force. Moreover, the inner layer 20 and the intermediate layer 30 can be securely bonded together by the bonding. Therefore, durability against repeated pressing and chemical resistance can be reliably improved.

  The porous fluororesin 32 of the intermediate layer 30 can usually be selected from the fluororesins exemplified in the inner layer 20 described above, and preferably PTFE, PFA, PVDF, etc. (particularly PTFE) can be selected. As the porous PTFE, the aforementioned ePTFE can be used. As the porous PFA, a PFA having pores formed by forming a mixture of a PFA powder and a solvent-soluble fine powder and then eluting the soluble fine powder with a solvent can be used. As the porous PVDF, PVDF having pores formed by a dissolution method or the like can be used.

  A preferred porous fluororesin 32 is a stretched porous fluororesin 32. Although the extending | stretching direction of the extending | stretching porous fluororesin 32 is not specifically limited, It is preferable to be extended | stretched in the direction (circumferential direction) orthogonal to the longitudinal direction of a tube. If the tube is stretched in the circumferential direction, it is possible to reduce a phenomenon (longitudinal crack) in which the tube is split in the longitudinal direction when the tube is repeatedly pressed. The stretched porous fluororesin 32 may be uniaxially stretched or biaxially stretched, but is preferably biaxially stretched.

  A preferred stretched porous fluororesin 32 is ePTFE. According to ePTFE, the porosity can be made sufficiently high, and a sufficient amount of the elastic body 31 can be filled in the pores. Moreover, it is excellent in a softness | flexibility and there is no possibility that the function of the elastic body 31 may be reduced. Furthermore, it is excellent in mechanical strength. ePTFE is available as “ePTFE film” from Japan Gore-Tex Co., Ltd.

  The porosity of the porous fluororesin 32 of the intermediate layer 30 is, for example, about 40 to 98%, preferably about 50 to 95%, and more preferably about 60 to 90%. When the porosity is too small, the filling amount of the elastic body 31 becomes small, and the pressing force buffering function is lowered. On the other hand, if the porosity is too large, the mechanical strength of the porous fluororesin 32 is reduced, and the bonding force with the inner layer 20 is reduced.

  The maximum pore diameter of the porous fluororesin 32 in the intermediate layer 30 is determined in view of characteristics (ease of filling) of the elastic body [or elastic raw material for forming the elastic body (described later in detail)]. Therefore, it may be set as appropriate, for example, 0.01 μm or more, preferably 0.1 μm or more, and 20 μm or less, preferably 10 μm or less. If the maximum pore diameter is too small, it is difficult to fill the elastic body. If the maximum pore diameter is too large, the mechanical strength may be insufficient. The maximum pore diameter can be measured in accordance with ASTM F316-86 regulations (agent used: ethanol).

  The form of the porous fluororesin 32 of the intermediate layer 30 is not particularly limited, and is obtained by extruding a wound porous film obtained by winding a porous fluororesin film or a fluororesin into a tube shape. Any of porous extruded tubes and the like may be used. A preferred form is a wound porous film. According to the wound porous film, an intermediate layer having high mechanical strength can be formed, and the stretching direction of the fluororesin is easily matched with the circumferential direction of the tube.

  When the intermediate layer 30 is formed of a wound porous film, the same treatment as when the inner layer 20 is formed of a wound film may be performed. That is, the films may be heat-sealed, the film winding end may be tapered, the end (end line) of the winding end may be inclined with respect to the tube center axis, and the film thickness May be sufficiently thin (for example, about 1 to 100 μm, preferably about 5 to 50 μm, more preferably about 10 to 40 μm), and the film may be subjected to a surface treatment. Note that the inner surface and / or outer surface of the intermediate layer 30 may be subjected to the surface treatment.

  On the other hand, as the elastic body 31 that fills the pores of the porous fluororesin 32, various liquid elastic material raw materials exemplified in the outer layer 10 can be used. A preferable liquid elastic material is the same as that for the outer layer 10.

  The elastic body 31 of the intermediate layer 30 and the elastic body 11 of the outer layer 10 are preferably selected from the same resin. If the same resin is selected, the bondability between the intermediate layer 30 and the outer layer 10 can be improved. By the way, the “same resin” means the same from the viewpoint of bonding properties, and preferably refers to a group of resins having the same monomer, a common monomer component, and the like. And a group of resins in which the main monomer is of the same strain.

  Similarly to the elastic body 11 of the outer layer 10, the elastic body 31 of the intermediate layer 30 may be used in combination with other materials. For example, the elastic body 31 may be mixed with organic fibers, inorganic fibers, carbons, metal fine particles, inorganic powders, and the like.

  The tensile strength of the elastic body 31 of the intermediate layer 30 can be designed from the viewpoint of the bondability with the outer layer 10, and the range is about the same as the tensile strength of the elastic body 11 of the outer layer 10.

The tensile strength (JIS K 6249) of the intermediate layer 30 formed from the elastic body 31 and the porous fluororesin 32 is, for example, about 0.1 to 75 MPa, preferably about 2 to 75 MPa, and more preferably 5 to 75 MPa. Degree. The storage elastic modulus E ′ (temperature 20 ° C., frequency 1 Hz, compression method) of the intermediate layer 30 is, for example, about 1 × 10 ² to 1 × 10 ⁸ Pa, preferably 1 × 10 ³ to 1 × 10 ⁸ Pa. The degree is more preferably about 1 × 10 ⁶ to 1 × 10 ⁸ Pa. If the mechanical strength or the storage elastic modulus E ′ is too low, the durability of the tube against repeated pressing decreases. On the other hand, when the storage elastic modulus E ′ is too high, the followability to the outer layer 10 (elastic layer) is lowered, and the durability of the tube against repeated pressing is lowered.

  The thickness of the intermediate layer 30 is, for example, about 10 to 2000 μm, preferably about 20 to 1500 μm, and more preferably about 50 to 1000 μm. If the intermediate layer 30 is too thin, the durability when the tube is pressed decreases. On the other hand, when the intermediate layer 30 is too thick, the elastic function of the outer layer 10 starts to be inhibited.

  In addition, since the intermediate layer 30 of the present invention is joined to the fluororesin layer 20 on the inner surface, the porous fluororesin 32 is exposed on the inner surface side. Further, the elastic body 31 is exposed on the outer surface side of the intermediate layer 30 in order to join to the outer elastic layer 10.

4: Manufacturing Method The laminated elastic tube of the present invention joins the inner fluororesin layer 20 and the porous fluororesin 32 of the intermediate layer 30, and the elastic body 31 of the intermediate layer 30 and the elastic body of the outer layer 10. 11 and can be obtained. By joining them, the inner layer 20, the intermediate layer 30, and the outer layer 10 can be integrated.

  It is recommended that the inner fluororesin layer 20 and the porous fluororesin 32 of the intermediate layer 30 be bonded by thermal fusion. However, a fluororesin for adhesion (melting fluororesin, fluororesin) Adhesion (thermal fusion) may be performed after interposing a dispersion. In the case of heat fusion, it is important to prevent thermal decomposition of the fluororesin. Therefore, as described above, it is desirable to previously grasp the melting point and thermal decomposition conditions (temperature, time) of the fluororesin using a DSC (differential scanning calorimeter), a TG (thermogravimetric analyzer), or the like.

  The elastic body 31 of the intermediate layer 30 and the elastic body 11 of the outer layer 10 may be joined by primer treatment, or may be joined via an adhesive, but are desirably joined directly. If directly joined, there is no risk of impairing the elasticity of the intermediate layer 30 and the outer layer 10. When the elastic body 31 of the intermediate layer 30 and the elastic body 11 of the outer layer 10 are directly joined, a three-dimensional network structure (at least one elastic body material is brought into contact with the other elastic body (or elastic body material) ( Curing). The rubbery body can be three-dimensional network structured (cured) by crosslinking. The thermoplastic elastomer can be formed into a three-dimensional network structure (cured), for example, by cooling from a thermoplastic state or by removing the cause of fluidization such as a solvent. The most preferable joining method is a method in which the elastic raw material 31 of the intermediate layer 30 and the elastic raw material 11 of the outer layer 10 are brought into contact with each other, and both elastic raw materials 31 and 11 are made into a three-dimensional network structure (curing). According to this method, higher bonding strength can be obtained.

  Various production methods can be adopted for the laminated elastic tube of the present invention as long as the above-described joining is possible. For example, (Method 1) the outer side of the inner layer 20 may be coated with the intermediate layer 30, and then the outer side of the intermediate layer 30 may be coated with the outer layer 10. (Method 2) A laminate of the intermediate layer 30 and the outer layer 10 was formed. Thereafter, the inner layer 20 may be coated on the inner surface of the intermediate layer 30. In any of the methods 1 and 2, the filling of the liquid elastic material 31 into the intermediate layer 30 may be performed before the intermediate layer 30 is stacked or after the intermediate layer 30 is stacked. Further, the timing of curing the liquid elastic material 31 of the intermediate layer 30 is not particularly limited.

  A preferred manufacturing procedure is (Method 1) in which the outer side of the inner layer 20 is coated with the intermediate layer 30 and then the outer side of the intermediate layer 30 is coated with the outer layer 10. According to this method 1, the inner layer fluororesin 20 and the intermediate layer 30 porous fluororesin 32 can be heat-sealed.

  In the case of this method 1, it is desirable to fill the liquid elastic material 31 into the intermediate layer 30 (porous fluororesin 32) after the intermediate layer 30 (porous fluororesin 32) is laminated (method 1-1). . When the liquid elastic material 31 is filled after the lamination, the porous fluororesin 32 is exposed without being covered by the liquid elastic material 31 before the lamination. Therefore, the inner layer fluororesin 20 and the intermediate layer porous fluororesin 32 can be reliably heat-sealed. Further, there is no possibility that the elastic body 31 is thermally deteriorated under the heat sealing condition. Then, after covering the inner layer 20 (tube made of a fluororesin layer) with the porous fluororesin 32 and thermally fusing them, a liquid elastic body is provided from the porous fluororesin 32 side to the pores of the porous fluororesin 32. The raw material 31 is filled, and after filling, a three-dimensional network structure may be formed.

  When the liquid elastic material 31 is filled in the intermediate layer 30 (porous fluororesin 32), the required amount may be filled accurately, or after excessive filling, the excess may be scraped off. Moreover, you may cure | harden and use as the outer layer 10 (elastic layer), without scraping off an excess part.

  When the laminated elastic tube is manufactured by the method 1-1, the outer layer 10 may be laminated on the intermediate layer 30 after being cured (Method A), or may be laminated on the intermediate layer 30 in an uncured state. Then, it may be cured (Method B). In the case of Method A, the intermediate layer 30 and the outer layer 10 can be joined by using a primer treatment or an adhesive. A preferred method is Method B. According to the method B, the elastic body 31 of the intermediate layer 30 and the elastic body 11 of the outer layer 10 can be directly joined.

  When the uncured outer layer 10 (liquid elastic material, solid (kneadable) elastic material, etc.) is laminated on the intermediate layer 30 (Method B), the uncured outer layer 10 is an elastic body to the intermediate layer 30. After the filling of the raw material 31, it may be laminated on the intermediate layer 30 (Method B1), or the intermediate layer 30 may be laminated on the intermediate layer 30 while also filling the intermediate raw material 31 (particularly the liquid elastic raw material). (Method B2). In the case of Method B1, the uncured outer layer 10 may be laminated after the elastic material 31 of the intermediate layer 30 is cured (Method B1a), and the uncured elastic material 31 of the intermediate layer 30 is uncured before curing. The outer layer 10 may be laminated (Method B1b). In the case of Method B2 and Method B1b, the elastic material 31 of the intermediate layer 30 and the elastic material 11 of the outer layer 10 can be cured at the same time, and the bonding strength can be significantly increased. In the case of the method B1b, the elastic body 31 of the intermediate layer 30 and the elastic body 11 of the outer layer 10 are preferably selected from the same resin, but different resins may be used.

A specific method for forming the outer layer 10 is exemplified as follows.
(I) A cylindrical intermediate body obtained by heat-sealing the inner layer 20 (a tube made of a fluororesin layer) and the porous fluororesin 32 is a center of a cylindrical body having an inner diameter larger than the outer diameter of the intermediate body. The elastic raw material 11 (liquid elastic raw material, solid (kneadable) elastic raw material, etc.) is cast in the gap, and is demolded after curing. When a die is used as a cylindrical body, a nipple is often used in order to correctly set the cylindrical intermediate body.
(Ii) Method of laminating elastic material 11 (especially solid (kneadable) elastic material) on the outer surface of the cylindrical intermediate body by extrusion, adjusting the outer surface, and then curing (iii) the cylindrical intermediate material Method of laminating elastic material 11 (especially solid (kneadable) elastic material) on the outer surface of the body by extrusion and curing, and then adjusting the outer surface by polishing or the like (iv) Elastic material 11 (first A laminated film 10 composed of a layer 12) and a porous film (second layer 13) impregnated with the elastic material 11 (particularly a liquid elastic material), and the elastic material 11 (first layer 12). (V) A method in which the cylindrical intermediate body 30 is wound around the outer surface of the cylindrical intermediate body and cured (v) in the outer layer 10 (elastic tube) that has been molded into a cylindrical shape and cured in advance. Insert the body, glue these etc. Therefore a method for joining Note these (i) ~ (v) but is assumes a production batch, if necessary, modify, or may be continuously produced. Further, after forming a cured or uncured elastic layer by the method (iv), an elastic layer is further formed by the method (i) to (iii) or (v). May be combined as appropriate.

5: Wear resistant layer 40
In the laminated elastic tube of the present invention, as shown in the schematic cross-sectional view of FIG. 4, a wear resistant layer 40 (wear resistant tube) may be further formed outside the outer layer 10 (elastic layer) as required. . The wear resistance layer 40 can further enhance the durability of the tube.

  For the wear resistant layer 40 (wear resistant tube), polymer materials such as vinyl chloride, polystyrene, polyester (polyethylene terephthalate, etc.), polyolefin (polyethylene, polypropylene, etc.), polyamide, polyimide, fluororesin, and inorganic materials such as glass fiber. Various materials such as can be used.

  In addition, the wear-resistant layer 40 (wear-resistant tube) is formed of a coated body, an extruded tube, an extruded stretched tube, a stretched film wound body, a solid film wound body, a porous film wound body, and a thread into a tube shape. It may be any shape such as a knitted knitted body, a woven fabric, a knitted fabric, a braided body, a lace, a wound body such as a net. It is important that the wear-resistant layer 40 has both the followability to the elastic layer 10 and the wear resistance, and the shape can be selected according to the hardness of the material.

  The wear resistant layer 40 (wear resistant tube) may or may not be fixed to the elastic layer 10, but is preferably fixed from the viewpoint of further improving the wear resistance. When the wear resistant layer 40 and the elastic layer are fixed, the fixing method is not particularly limited. For example, the wear resistant layer 40 and the elastic layer may be fixed using an adhesive, but by using the same elastic body as the outer layer 10 as an adhesive, It is preferable to fix the wear layer 40. It is also preferable to laminate and fix the wear resistant layer 40 (wear resistant tube) using the shrinkage force of the wear resistant layer 40 (wear resistant tube). If the contraction force is used, the elasticity of the tube is not impaired.

  A preferred wear-resistant layer 40 (wear-resistant tube) is a fluororesin tube, particularly PTFE tube. Fluororesin tube-like materials (particularly PTFE tube-like materials) are excellent in wear resistance, chemical resistance, heat resistance, and the like.

  When the wear-resistant tube 40 is formed of a fluororesin (particularly PTFE), the tube includes a wound body of a porous fluororesin film, a knitted body in which the fluororesin yarn is knitted in a tube shape, a fabric made of a fluororesin yarn, It is desirable to use a wound body in which a knitted fabric, a braided article, a lace, a net or the like is wound. If these are used, since the adhesive or elastic material penetrates into the pores or between the fibers, the wear-resistant layer 40 can be firmly joined to the elastic layer 10.

  A plurality of wear-resistant layers 40 (wear-resistant tubes) may be stacked, for example, a fluororesin tube and a glass cloth wound body may be stacked.

6: Laminated elastic tube The size of the laminated elastic tube of the present invention varies depending on the application and is difficult to define uniformly. For example, when used for elastic tubes for pinch valves and roller pumps, 1 mm or more (for example, about 1 to 40 mm), outer diameter: 100 mm or less (for example, about 3 to 100 mm, particularly about 5 to 60 mm), and a length of about 50 to 1500 mm.

7: Fluid flow control member The laminated elastic tube of the present invention can be used as a member that controls the flow of fluid by pressing, for example, as an elastic tube of a pinch valve or a roller pump. A pinch valve is a fluid in the tube that presses the elastic tube in the radial direction from the side with a pinch valve that operates with fluid pressure (pneumatic pressure, hydraulic pressure, etc.) or electricity to flatten (especially block) the tube cross section. It is a device that controls the distribution of The roller pump presses the elastic tube in the radial direction with a pressing member such as a roller, and moves the pressing member in the axial direction of the elastic tube while maintaining this pressed state (especially moving repeatedly from the upstream side to the downstream side). ) To send out the fluid in the tube.

  The type of fluid flowing through the tube is not particularly limited, and may be either gas or liquid, but is preferably liquid. In particular, the laminated elastic tube of the present invention has excellent chemical resistance, so it is highly corrosive used in the fields of photoresist liquid, liquid for operating process machinery, pharmaceutical, food, medical, chemistry, etc. It is also possible to circulate a fluid such as liquid. In addition, since the laminated elastic tube of the present invention has low tackiness, it can be used even for applications that dislike the flow component adhering to the inner surface of the tube.

  Furthermore, the laminated elastic tube of the present invention can also be used as a cable tube (push-pull tube) in which a metal wire for transmitting torque or the like is inserted into the tube. Since the elastic tube of the present invention has a high sliding property of the fluororesin layer 20 on the inner surface, torque can be transmitted smoothly.

  When the laminated elastic tube of the present invention is used for applications where elasticity is not necessarily required such as a hose or piping, the outer elastic layer 10 is not necessary.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

Example 1
Using a calender roll device with outer diameter: 300 mm, width: 600 mm, rolling reaction force: 1 MN (maximum), roll temperature: 70 ° C., linear pressure: 8 N / mm ² , feed rate: 6 m / min. Compressed stretched porous PTFE film (“ePTFE film” manufactured by Japan Gore-Tex Co., Ltd., width: 500 mm, porosity: 90%, thickness: 20 μm), width: 500 mm, length: 500 mm, pores A white turbid film having a rate of 5% and a thickness of 2.1 μm was obtained. This white turbid film is sandwiched between two polyimide films ("UPILEX 20S" (trade name) manufactured by Ube Industries, Ltd.), press surface size: 750 mm x 750 mm, maximum pressure: 2MN hot press device , And press the plate for 5 minutes under the conditions of press plate temperature: 400 ° C. and surface pressure: 10 N / m ² , and then gradually cool the press plate temperature to 25 ° C. over 60 minutes while maintaining the surface pressure. Thus, a transparent PTFE film (densified PTFE film) having a width of 500 mm, a length of 500 mm, a porosity of 0%, and a thickness of 2 μm was obtained.

  The densified PTFE film is cut into a size of width: 400 mm and length (depth): 158 mm, and a stainless steel bar (outer diameter) so that the length (depth) direction becomes the winding direction (circumferential direction). : 5 mm) was wound 10 times to form an inner layer having a thickness of about 20 μm.

  Biaxially stretched porous PTFE film as a porous fluororesin for the intermediate layer (“ePTFE film” manufactured by Japan Gore-Tex Co., Ltd.), width: 400 mm, length (depth): 81 mm, porosity: 85%, maximum The pore diameter: 0.5 μm, thickness: 20 μm) was wound on the inner layer (the number of turns: 5) so that the length (depth) direction was the winding direction (circumferential direction). This wound product was heated at a temperature of 375 ° C. for 30 minutes using a forced hot air circulation / ventilation type constant temperature and humidity chamber (manufactured by Espec Co., Ltd., “STPH-201”). Between the films of the resin film and between the inner layer film and the porous fluororesin film, a cylindrical intermediate body having an outer diameter of 5.2 mm was obtained using a stainless steel rod having an outer diameter of 5 mm as a core material. . 10 g of addition reaction type liquid silicone rubber (“KE1031” manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the porous fluororesin film surface of the cylindrical intermediate using a rubber spatula and impregnated in the pores. . Excess silicone rubber was scraped off with a rubber spatula and non-woven wiper.

  Separately, heat-curing type millable silicone rubber (“KE551-U” manufactured by Shin-Etsu Chemical Co., Ltd.) pre-mixed with additives such as reinforcing fillers and plasticizers and a vulcanizing agent (Shin-Etsu Chemical Co., Ltd.) ) "C-23") was blended at a mass ratio of 100: 1 and kneaded using a mixing roll machine. The cylindrical intermediate body was inserted from the inlet side into a metal extrusion crosshead in which a die having an inner diameter of 9.6 mm and a nipple having an inner diameter of 5.2 mm were concentrically arranged. The kneaded heat-vulcanized silicone rubber was pushed in from the intermediate side surfaces of the inlet and outlet of the extrusion crosshead with a screw. The cylindrical intermediate is discharged from the outlet side of the extrusion head by the pressure flow of rubber by indentation, then heated at a primary vulcanization temperature of 170 ° C. for 20 minutes, and further heated at a secondary vulcanization temperature of 200 ° C. for 4 hours. Thus, both the liquid silicone rubber and the millable silicone rubber were crosslinked.

  After cooling, twist the outer layer (elastic layer) by hand to loosen the crimp between the densified PTFE of the inner layer and the core material (stainless steel bar), and pull out the stainless steel bar to obtain a laminated elastic tube (Inner diameter: 5 mm, outer diameter: 9.6 mm, axial length: 400 mm, inner layer thickness: 20 μm, intermediate layer thickness: 100 μm, outer layer thickness: 2.2 mm).

Example 2
In the same manner as in Example 1, a cylindrical intermediate body impregnated with liquid silicone rubber was obtained.
Biaxially stretched porous PTFE film (“ePTFE film” manufactured by Japan Gore-Tex Co., Ltd.), width: 400 mm, length (depth): 816 mm, porosity: 78%, maximum pore diameter: 0.4 μm, thickness: 18 μm), an addition reaction type liquid silicone rubber (“KE1031” manufactured by Shin-Etsu Chemical Co., Ltd.) was applied from one side. The coated film was wound around the cylindrical intermediate body to make an outer layer while keeping the coated surface inside and preventing air from being caught (number of windings: 35 times).

  The liquid silicone rubber of the intermediate layer and the outer layer was crosslinked by heating at a temperature of 150 ° C. for 30 minutes.

  After cooling, twist the outer layer (elastic layer) by hand to loosen the crimp between the densified PTFE of the inner layer and the core material (stainless steel bar), and pull out the stainless steel bar to obtain a laminated elastic tube (Inner diameter: 5 mm, outer diameter: 9.6 mm, axial length: 400 mm, inner layer thickness: 20 μm, intermediate layer thickness: 100 μm, outer layer thickness: 2.2 mm, outer silicone rubber layer (First layer) thickness: 1550 μm, outer PTFE film layer (second layer) thickness: 630 μm, first layer thickness / second layer thickness = 2.5 / 1 ).

Example 3
The rubber to be impregnated into the pores of the biaxially stretched porous PTFE film of the intermediate layer is a heat-curing liquid fluororubber (“SIFEL-8070A / B” manufactured by Shin-Etsu Chemical Co., Ltd.), the biaxially stretched porous of the outer layer An elastic tube was obtained in the same manner as Example 2 except that the rubber to be applied to the PTFE film was a heat-curing liquid fluororubber (“SIFEL-610” manufactured by Shin-Etsu Chemical Co., Ltd.) (inner diameter: 5 mm, Outer diameter: 9.6 mm, axial length: 400 mm, inner layer thickness: 20 μm, intermediate layer thickness: 100 μm, outer layer thickness: 2.2 mm, outer fluororubber layer (first layer) Thickness: 1550 μm, outer PTFE film layer (second layer) thickness: 630 μm, first layer thickness / second layer thickness = 2.5 / 1).

Comparative Example 1
Heat-curing type millable silicone rubber (“KE551-U” manufactured by Shin-Etsu Chemical Co., Ltd.) and vulcanizing agent (manufactured by Shin-Etsu Chemical Co., Ltd.) pre-mixed with additives such as reinforcing fillers and plasticizers "C-23") was blended at a mass ratio of 100: 1 and kneaded using a mixing roll machine. A stainless steel rod having an outer diameter of 5 mm was inserted from the inlet side into a metal extrusion crosshead in which a die having an inner diameter of 9.6 mm and a nipple having an inner diameter of 5 mm were concentrically arranged. The kneaded heat-vulcanized silicone rubber was pushed in from the intermediate side surfaces of the inlet and outlet of the extrusion crosshead with a screw. The stainless steel rod is discharged from the outlet side of the extrusion head by the pressure flow of rubber by indentation, then heated at a primary vulcanization temperature of 170 ° C. for 20 minutes, and further heated at a secondary vulcanization temperature of 200 ° C. for 4 hours. Was used to crosslink the millable silicone rubber.

  After cooling, the outer silicone rubber was twisted by hand to loosen the pressure contact with the inner stainless steel bar, and the stainless steel bar was pulled out to obtain an elastic tube (inner diameter: 5 mm, outer diameter: 9. 6 mm, axial length: 400 mm, thickness: 2.3 mm).

Comparative Example 2
Biaxially stretched porous PTFE film used in Example 2 (“ePTFE film” manufactured by Japan Gore-Tex Co., Ltd.), width: 400 mm, length (depth): 826 mm, porosity: 78%, maximum pore diameter: 0 (4 μm, thickness: 18 μm), an addition reaction type liquid silicone rubber (“KE1031” manufactured by Shin-Etsu Chemical Co., Ltd.) was applied from one side. The coated film was wound around a stainless steel bar (outer diameter: 5 mm) while keeping the coated surface inside and preventing air from being caught (number of windings: 36 times). The liquid silicone rubber was crosslinked by heating at a temperature of 150 ° C. for 30 minutes.

  After cooling, the rubber part was twisted by hand to loosen the crimping with the inner stainless steel bar, and the elastic tube was obtained by pulling out the stainless steel bar (inner diameter: 5 mm, outer diameter: 9.6 mm) , Axial length: 400 mm, overall thickness: 2.3 mm, silicone rubber layer (first layer) thickness: 1650 μm, PTFE film layer (second layer) thickness: 650 μm, first Layer thickness / second layer thickness = 2.5 / 1).

Comparative Example 3
An elastic tube was obtained in the same manner as in Comparative Example 2 except that the rubber to be applied was a heat-curing liquid fluororubber (“SEIFEL-610” manufactured by Shin-Etsu Chemical Co., Ltd.) (inner diameter: 5 mm, outer diameter: 9.6 mm, axial length: 400 mm, overall thickness: 2.3 mm, fluororubber layer (first layer) thickness: 1650 μm, PTFE film layer (second layer) thickness: 650 μm , First layer thickness / second layer thickness = 2.5 / 1).

Comparative Example 4
A densified PTFE film was obtained in the same manner as in Example 1.
This densified PTFE film is cut into a size of width: 400 mm and length (depth): 158 mm, and a stainless steel bar (outer diameter) so that the length (depth) direction becomes the winding direction (circumferential direction). : 5 mm). Next, using a forced hot air circulation / ventilation type constant temperature and humidity chamber (“STPH-201” manufactured by Espec Corp.), the mixture was heated at a temperature of 375 ° C. for 30 minutes, and the PTFE film was heat-sealed to a thickness of 20 μm. The inner layer of was formed.

  Separately, heat-curing type millable silicone rubber (“KE551-U” manufactured by Shin-Etsu Chemical Co., Ltd.) pre-mixed with additives such as reinforcing fillers and plasticizers and a vulcanizing agent (Shin-Etsu Chemical Co., Ltd.) ) "C-23") was blended at a mass ratio of 100: 1 and kneaded using a mixing roll machine. The inner layer was inserted from the inlet side while being wound around a stainless steel bar, into a metal extrusion crosshead in which a die having an inner diameter of 9.6 mm and a nipple having an inner diameter of 5 mm were arranged concentrically. The kneaded heat-vulcanized silicone rubber was pushed in from the intermediate side surfaces of the inlet and outlet of the extrusion crosshead with a screw. The inner layer wound around the stainless steel bar is discharged from the outlet side of the extrusion head by the pressure flow of the rubber by indentation, and then heated at a primary vulcanization temperature of 170 ° C. for 20 minutes, and further at a secondary vulcanization temperature of 200 ° C. The millable silicone rubber was crosslinked by heating for a period of time.

  After cooling, the outer layer (elastic layer) was twisted by hand to loosen the pressure-bonding between the densified PTFE of the inner layer and the core material (stainless steel bar), and an elastic tube was obtained by pulling out the stainless steel bar ( (Inner diameter: 5 mm, outer diameter: 9.6 mm, axial length: 400 mm, inner layer thickness: 20 μm, outer layer thickness: 2.3 mm).

  The chemical resistance and durability of the elastic tubes obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were examined as follows.

Chemical resistance Cyclohexane was filled in the hollow of the elastic tube and kept at a temperature of 20 to 25 ° C. for 70 hours. After discharging cyclohexane, the mass change of the tube before and after the test was measured and evaluated according to the following criteria.
Excellent: Mass change is less than 30% Impossibility: Mass change is 30% or more

Durability An elastic tube was attached to a resin-made pinch valve (manufactured by Asahi Organic Materials Co., Ltd., trade name “Dymatrix AVPV3”) for wet process. This pinch valve can press a 15 mm × 10 mm prismatic piston (the peripheral edge of the tip is chamfered (curvature 0.4)) against the flat plate with compressed air. Press the tube between. The elastic tube was repeatedly pressed with a piston without passing liquid through the tube. The conditions for pressing are as follows.
Pressing time: 1.5 seconds / time Pressure release time: 1.5 seconds / time Compressed air pressure: 0.4 MPa

  The outer surface of the tube was visually confirmed, and the number of repetitions until damage occurred was counted. Moreover, the cross section of the tube was confirmed visually and the number of repetitions until delamination occurred was counted.

  As is clear from Table 1, the elastic tubes of Examples 1 to 3 are excellent in durability against repeated pressing and chemical resistance because the inner layer and the outer layer (elastic layer) are joined by an appropriate intermediate layer. ing.

FIG. 1 is a schematic cross-sectional view showing an example of the laminated elastic tube of the present invention. FIG. 2 is an enlarged view of a main part of the laminated elastic tube of the present invention. FIG. 3 is a schematic sectional view showing an example of an outer layer (elastic layer) used in the present invention. FIG. 4 is a schematic sectional view showing another example of the laminated elastic tube of the present invention.

Explanation of symbols

10 Outer layer (elastic layer)
20 Inner layer (fluorine resin layer)
30 Intermediate layer 11, 31 Elastic body (elastic body material)
32 Porous fluororesin 12 First layer 13 Second layer 40 Abrasion resistant layer (abrasion resistant tube)

Claims (33)

A laminated elastic tube having an inner surface made of a fluororesin layer and an elastic layer formed outside the fluororesin layer,
Between the fluororesin layer and the elastic layer, an intermediate layer composed of a porous fluororesin and an elastic body filling the pores of the porous fluororesin is formed,
The fluororesin layer on the inner surface and the porous fluororesin in the intermediate layer are joined,
A laminated elastic tube, wherein an outer elastic layer and an elastic body of an intermediate layer are joined.   The laminated elastic tube according to claim 1, wherein the fluororesin layer on the inner surface is a tube around which a fluororesin film is wound.   The laminated elastic tube according to claim 1 or 2, wherein the fluororesin layer on the inner surface is a stretched fluororesin layer.   The laminated elastic tube according to claim 3, wherein a stretching direction of the stretched fluororesin layer is orthogonal to a length direction of the tube.   The laminated elastic tube according to claim 3 or 4, wherein the stretched fluororesin layer is a solid stretched fluororesin layer.   The laminated elastic tube according to claim 5, wherein the solid stretched fluororesin layer is a solid stretched polytetrafluoroethylene layer.   The laminated elastic tube according to claim 1 or 2, wherein the fluororesin layer on the inner surface is formed of a meltable fluororesin.   The laminated elastic tube according to claim 7, wherein the meltable fluororesin is PFA, FEP, PVDF, THV, or EFEP.   The laminated elastic tube according to claim 1, wherein the fluororesin layer on the inner surface is obtained by laminating two or more kinds of fluororesins.   The laminated elastic tube according to claim 9, wherein the two or more types of fluororesins are each formed into a tube, and the tubes are sequentially stacked from the inside.   The laminated elastic tube according to claim 9, wherein the two or more kinds of fluororesin are laminated in a planar shape, and the planar laminate is wound into a tube shape to form the fluororesin layer on the inner surface. .   The laminated elastic tube according to any one of claims 9 to 11, wherein one of the two or more types of fluororesins is a fully stretched fluororesin.   The laminated elastic tube according to any one of claims 9 to 12, wherein one of the two or more fluororesins is a meltable fluororesin.   The laminated elastic tube according to claim 13, wherein the meltable fluororesin is disposed on the outermost side of the fluororesin layer on the inner surface.   The laminated elastic tube according to claim 13 or 14, wherein the meltable fluororesin is PFA, FEP, PVDF, THV, or EFEP.   The laminated elastic tube according to claim 1, wherein the fluororesin layer on the inner surface and the porous fluororesin in the intermediate layer are heat-sealed.   The laminated elastic tube according to any one of claims 1 to 16, wherein the porous fluororesin of the intermediate layer is porous polytetrafluoroethylene.   The laminated elastic tube according to any one of claims 1 to 17, wherein the elastic body of the intermediate layer is at least one selected from silicone elastomers, fluorine elastomers, and fluorosilicone elastomers.   The elastic body of the intermediate layer is at least selected from polyester-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, styrene-based block copolymer elastomers, thermoplastic vulcanized elastomers, and polyamide-based thermoplastic elastomers. The laminated elastic tube according to any one of claims 1 to 17, which is a kind.   The laminated elastic tube according to any one of claims 1 to 19, wherein the outer elastic layer is at least one selected from silicone elastomers, fluorine elastomers, and fluorosilicone elastomers.   The outer elastic layer is at least one selected from polyester-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, styrene-based block copolymer elastomers, thermoplastic vulcanized elastomers, and polyamide-based thermoplastic elastomers. The laminated elastic tube according to any one of claims 1 to 19.   The laminated elastic tube according to any one of claims 1 to 21, wherein the elastic body of the intermediate layer and the elastic body of the outer elastic layer are both formed of the same resin. The laminated elastic tube according to any one of claims 1 to 22, wherein a storage elastic modulus E 'of the outer elastic layer is 1 x 10 ² to 1 x 10 ⁸ Pa.   The outer elastic layer includes (1) a first layer made of an elastic body, (2) a porous polytetrafluoroethylene film, and an elastic body filling the pores of the porous polytetrafluoroethylene film. The laminated elastic tube according to any one of claims 1 to 23, wherein the laminated elastic tube has a spiral laminated structure in which the second layer is overlapped.   The laminated elastic tube according to claim 24, wherein a ratio of the thickness of the first layer to the thickness of the second layer (first layer / second layer) is 6.5 / 1 or less.   The thickness of the fluororesin layer on the inner surface is 1 to 200 µm, the thickness of the intermediate layer is 10 to 2000 µm, and the thickness of the outer elastic layer is 0.15 to 80 mm. A laminated elastic tube according to any one of the above.   The laminated elastic tube according to any one of claims 1 to 26, wherein a thickness of the outer elastic layer is 10 to 200% with respect to an inner diameter of the laminated elastic tube.   The laminated elastic tube according to any one of claims 1 to 27, wherein an abrasion-resistant layer is formed outside the outer elastic layer.   29. The laminated elastic tube according to claim 28, wherein the wear-resistant layer is a polytetrafluoroethylene tube.   A pinch valve using the laminated elastic tube according to claim 1.   A roller pump using the laminated elastic tube according to claim 1. After coating a tube made of a fluororesin layer with a porous fluororesin and thermally fusing them,
Filling the pores of the porous fluororesin from the porous fluororesin side with a liquid elastic material,
The method for producing a laminated elastic tube according to any one of claims 1 to 29, wherein after the filling, a three-dimensional network structure is formed to make the elastic raw material into an elastic body. After coating a tube made of a fluororesin layer with a porous fluororesin and thermally fusing them,
Filling the pores of the porous fluororesin from the porous fluororesin side with a liquid elastic material,
Further, after forming a layer containing an elastic material on the outside of the porous fluororesin,
The method for producing a laminated elastic tube according to any one of claims 1 to 29, wherein a three-dimensional network structure is formed to make both elastic raw materials into an elastic body.