JP4437346B2 - Fluid transfer insulation tube and method for manufacturing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid transfer heat retaining tube used for transferring a heating gas such as water vapor, a heating liquid such as hot water or a liquid heating chemical, and a manufacturing method thereof.
[0002]
[Prior art]
When a heated gas such as water vapor or a heated liquid such as warm water or liquid heated chemical is transferred, a fluid transfer heat retaining tube in which the outer surface of the resin tube is covered with a heat retaining layer made of foamed resin is generally used.
Conventionally, such a fluid transfer heat insulating tube has been prepared by separately forming a resin tube and a tube-shaped heat insulating layer made of foamed resin so that the outer diameter of the resin tube is substantially equal to the inner diameter of the foamed resin heat insulating tube. The resin tube was press-fitted into the foamed resin insulation tube, or the foamed resin protection tube was made larger than the outer diameter of the resin tube, and the resin tube was inserted into the foamed resin insulation tube. .
When the fluid transfer heat insulation tube is prepared by such a method, in the former case, it is difficult to press-fit the resin tube into the foamed resin heat insulation tube, and the length of the tube is limited to 30 m at most. Production of a shank tube was virtually impossible. On the other hand, in the latter case, there is a problem that a gap is generated between the resin tube and the foamed resin heat insulating tube, and the heat insulating and heat insulating effects are likely to be uneven.
As a method for continuously producing a long fluid transfer heat insulating tube, a method of forming a foamed resin heat insulating layer by extruding a foamed resin on a resin tube can be considered. The coated foamed resin swells in the diametrical direction and tries to extend in the longitudinal direction. At that time, the foamed resin does not slide smoothly on the inner resin tube surface, causing stick-slip, and as a result, as shown in FIG. Furthermore, constriction occurs in the foamed resin heat insulating layer 2 on the resin tube 1. The occurrence of such a neck causes deterioration of heat insulation and heat retention performance and also deteriorates the appearance.
Also, if the resin tube and the foamed resin heat insulating layer are bonded via a primer layer, the foamed resin is prevented from stretching in the longitudinal direction during vulcanization, and the stick-slip as described above does not occur, and foaming It is thought that the resin heat insulation layer will not be constricted, but since the resin tube and the foam resin heat insulation layer are adhered, when connecting the tube with a joint, etc., the foam resin heat insulation layer is removed from the resin tube. The so-called terminal processing to be peeled off becomes difficult, and there arises a problem that workability at the time of use is remarkably lowered.
[0003]
[Problems to be solved by the invention]
It is an object of the present invention to solve the above-mentioned problems of the prior art, and to provide a long fluid transfer heat retaining tube that is free from constriction in the foamed resin heat retaining layer and that can be easily treated, and a method for manufacturing the same. Is.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors fixed the resin tube between the resin tube and the foamed resin heat insulation layer without adhering to the foamed resin heat insulation layer. The present invention has been completed with the idea of providing an intermediate layer to be bonded.
That is, according to the present invention,
(1) In a fluid transfer heat insulating tube in which the outer surface of the fluororesin tube is covered with a foamed silicone resin / rubber heat insulating layer , the fluororesin tube is different from the fluororesin tube between the fluororesin tube and the foamed silicone resin / rubber heat insulating layer. in no adhesion to the fluororesin tube, it is with the foamed silicone resin, rubber insulation layer having a middle layer made of silicone rubber having adhesiveness with respect to the foamed silicone resin, rubber insulation layer in a homogeneous A fluid transfer insulation tube characterized by:
( 2 ) The fluid transfer heat insulation tube according to (1), wherein the intermediate layer is a silicone rubber coating layer;
( 3 ) The fluid transfer heat retaining tube according to (1) or (2), wherein the outer surface of the intermediate layer is coated with the foamed silicone resin / rubber heat retaining layer and then vulcanized .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the fluid transfer heat retaining tube of the present invention covers the outer surface of a resin tube 1 with a foamed resin / rubber heat insulating layer 2, and between the resin tube 1 and the foamed resin / rubber heat insulating layer 2. The resin tube 1 is fixed without being bonded, and the foamed resin / rubber heat insulating layer 2 is provided with a bonded intermediate layer 3.
As the material of the resin tube 1, an appropriate resin can be used according to the type of fluid to be transferred. For example, polyolefin resin, polyvinyl chloride resin, fluororesin, polyester resin, polyamide resin, polyimide resin, polyurethane resin, polyethylene A resin that can be extruded, such as a resin, can be used. In particular, a fluororesin is preferably used because of excellent heat resistance and chemical resistance. Examples of the fluororesin include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and tetrafluoroethylene-ethylene copolymer. Examples thereof include a polymer (E / TFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and chlorotrifluoroethylene-ethylene copolymer (E / CTFE).
The outer diameter, thickness, etc. of the resin tube 1 are appropriately set according to the purpose of use of the fluid transfer heat retaining tube.
In addition, as the foamed resin / rubber constituting the foamed resin / rubber heat retaining layer 2, the foamed resin / rubber usually used as a heat retaining material, for example, foamed silicone rubber, foamed urethane resin, depending on the temperature of the use environment In addition, foams of various rubbers / resins can be used. In particular, foamed silicone rubber is preferably used because of excellent heat insulation, heat retention, and flexibility.
The thickness of the foamed resin / rubber heat insulating layer 2 is appropriately set according to the purpose of use of the fluid transfer heat insulating tube.
[0006]
The intermediate layer 3 provided between the resin tube 1 and the foamed resin / rubber thermal insulation layer 2 is firmly adhered to the foamed resin / rubber thermal insulation layer 2 and is not adhered to the resin tube 1 and is vulcanized. It is necessary that the foamed resin / rubber heat insulating layer 2 is fixed to the resin tube 1 to an extent sufficient to prevent the foamed resin / rubber heat insulating layer 2 from extending in the longitudinal direction.
The intermediate layer 3 provided between the resin tube 1 and the foamed resin / rubber heat insulating layer 2 is fixed to the resin tube 1 without being bonded, and is bonded to the foamed resin / rubber heat insulating layer 2. There is no particular limitation, and a layer made of any organic or inorganic material can be used.
For example, the intermediate layer 3 is different from the resin tube 1 and has no adhesiveness to the resin tube 1, and the same kind as the foamed resin / rubber thermal insulation layer 2 and has adhesiveness to the foamed resin / rubber thermal insulation layer 2. If an elastomer resin / rubber is used, the intermediate layer 3 is firmly bonded to the foamed resin / rubber insulation layer 2 by vulcanization, and is not bonded to the resin tube 1 but is pressed against the resin tube 1 by its elasticity. The foamed resin / rubber heat insulating layer 2 can be prevented from extending in the longitudinal direction during vulcanization.
As a suitable example, when a fluororesin is used for the resin tube 1 and a foamed silicone resin is used for the foamed resin / rubber heat insulating layer 2, an example in which silicone solid rubber is used for the intermediate layer 3 can be given. Silicone solid rubber has adhesiveness to the foamed silicone resin of the foamed resin / rubber thermal insulation layer 2, while it has no adhesiveness to the fluororesin of the resin tube 1, and the fluororesin tube 1. Since it is pressed and fixed due to its elasticity, it prevents expansion of the foamed resin / rubber heat insulating layer 2 in the longitudinal direction during vulcanization, and the foamed resin / rubber heat insulating layer 2 is not constricted. The foamed resin / rubber heat insulating layer 2 is not bonded to the resin tube 1 via the silicone solid rubber, and the terminal treatment becomes easy.
The thickness of the intermediate layer 3 is usually 1 mm or less, preferably 1/100 to 1/10 of the thickness of the foamed resin / rubber heat insulating layer 2, and particularly preferably 3/100 to 8/100. If this thickness is too thick, the heat insulating properties of the heat insulation tube tend to be lowered. If it is too thin, the effect of preventing the foamed resin / rubber heat insulation layer 2 from being elongated in the longitudinal direction during vulcanization is lowered, and foaming is performed. Constriction is likely to occur in the resin / rubber thermal insulation layer 2.
In addition, a metal foil layer may be provided on the inner surface or outer surface of the intermediate layer 3 in order to enhance the heat insulating effect. When provided on the inner surface of the intermediate layer 3, a metal foil that adheres to the intermediate layer 3 (uses an adhesive if necessary) and does not adhere to the resin tube 1 is used. What is necessary is just to carry out by tape winding pressure. On the other hand, when providing on the outer surface of an intermediate | middle layer, what is necessary is just to use the metal foil which adhere | attaches (uses an adhesive agent as needed) to both the foam resin / rubber heat insulation layer 2 and the intermediate | middle layer 3. In addition, when the metal foil is firmly fixed to the intermediate layer 3 by the pressure by tape winding of the metal foil, the use of an adhesive is not necessary.
As the metal foil provided on the inner surface or the outer surface of the intermediate layer 3, a metal foil having a large heat insulating effect such as an aluminum foil is used. Of course, when a metal foil is used as the intermediate layer 3, this heat insulating metal foil may not be used.
Furthermore, depending on the use of the fluid transfer heat retaining tube, a braided shield layer can be provided on the inner surface or outer surface of the intermediate layer 3 in order to improve the pressure resistance performance. As the braided shield, a metal braided shield such as tin-plated annealed copper wire, nickel-plated annealed copper wire, silver-plated annealed copper wire, stainless steel wire is usually used, and the arrangement method is the same as in the case of the above-mentioned heat-insulating metal foil. is there. However, when a braided shield is provided, the cutability and workability at the time of terminal processing are deteriorated, so it is necessary to use it after taking that point into consideration.
In addition, since the foamed resin / rubber thermal insulation layer 2 is foamed, its mechanical strength is low, it is easily damaged, and the surface has a porous structure so that liquids such as water and chemicals can penetrate. Therefore, it is preferable to provide a protective coating layer on the outer surface to prevent damage and liquid penetration.
Protective coating layers include inorganic material layers such as metals and ceramics, and organic material layers such as polyolefins, polyvinyl chloride, polyesters, polyamides, silicone resins, and fluororesins. Accordingly, it is appropriately used in consideration of adhesiveness with the foamed resin / rubber heat insulating layer 2. The thickness of the protective coating layer is usually about 0.01 to 0.5 mm.
[0007]
In order to manufacture the fluid transfer heat insulating tube of the present invention, the intermediate layer 3 fixed to the outer surface of the resin tube 1 without being bonded to the resin tube 1 and bonded to the foamed resin / rubber heat insulating layer 2 by vulcanization. After coating, the foamed resin / rubber heat insulating layer 2 is extrusion coated thereon, and then vulcanized to bond the intermediate layer 3 and the foamed resin / rubber heat insulating layer 2 together.
The intermediate layer 3 is an elastomer resin that is different from the resin tube 1 and has no adhesion to the resin tube 1, and is the same type as the foam resin / rubber insulation layer 2 and has adhesion to the foam resin / rubber insulation layer 2. Is used, the outer surface of the resin tube 1 is coated with an elastomer resin, the foamed resin / rubber heat insulating layer 2 is extrusion coated thereon, and then vulcanized to cure the intermediate layer 3 and the foamed resin / rubber heat insulating material. Layer 2 is adhered.
For example, when fluororesin is used for the resin tube 1, foamed silicone resin is used for the foamed resin / rubber insulation layer 2, and silicone rubber is used for the intermediate layer 3, which is a preferred example of the present invention, the outer surface of the fluororesin tube 1 is used. After coating the silicone solid rubber and extrusion coating the foamed silicone resin on it, heat vulcanize at a temperature of 150 ° C to 250 ° C for 10 minutes to 120 minutes to bond the silicone solid rubber and the foamed silicone resin. .
Further, if necessary, a metal foil layer or a braided shield layer may be provided on the inner surface or the outer surface of the intermediate layer 3. Furthermore, a protective coating layer made of the above-described various materials can be provided on the outer surface of the foamed resin / rubber thermal insulation layer 2 as required by any means such as coating or extrusion coating.
[0008]
According to the present invention, since the foamed resin / rubber heat insulating layer 2 and the intermediate layer 3 are bonded to each other, and the intermediate layer 3 is fixed to the resin tube 1, the extrusion-coated foamed resin / rubber heat insulating layer is provided. Even if the layer 2 tries to extend in the longitudinal direction during vulcanization, the extension is prevented and no constriction due to stick-slip on the surface of the resin tube 1 occurs, as shown in FIG. As described above, the surface of the foamed resin / rubber heat insulating layer 2 becomes flat, and the heat transfer and heat insulating performance are not deteriorated, and a fluid transfer heat insulating tube having a good appearance can be obtained.
Further, since the foamed resin / rubber heat insulating layer 2 is not bonded to the resin tube 1 via the intermediate layer 3, the foamed resin / rubber heat insulating layer 2 can be easily removed from the resin tube 1 when the tube is connected by a joint or the like. So that the so-called terminal processing becomes easy, and the workability during use is remarkably improved.
[0009]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these.
Example 1
The outer surface of a fluororesin (PFA) tube having an inner diameter of 22.22 mm and a wall thickness of 1.59 mm is coated and fixed with a silicone rubber (Toshiba Silicone Co., Ltd. TSE2571-5) to a thickness of 0.2 mm. A foamed silicone resin (Toshiba Silicone Co., Ltd. TSE2571-5) is extrusion coated to a thickness of 10 mm on the top, and then heated and vulcanized at 200 ° C. for 4 hours to bond the silicone rubber and the foamed silicone resin. It was.
Further, a fluororesin (PFA) was extrusion coated on the outer surface of the foamed silicone resin layer to provide a protective coating layer having a thickness of 0.1 mm.
The obtained fluid transfer heat retaining tube was a long tube having a length of 100 m, and no constriction was generated on the surface thereof, and it was flat as shown in FIG. 2 and had good heat insulation, heat retaining performance and appearance. Further, the foamed silicone resin layer could be easily peeled off from the fluororesin tube, and the terminal treatment was easy.
[0011]
Comparative Example 1
In Example 1, an intermediate layer made of silicone rubber was not used, and the others were the same as Example 1, and a fluid transfer heat insulation tube was prepared.
As shown in FIG. 3, constriction occurred on the surface of the obtained fluid transfer heat insulation tube, and heat insulation, heat insulation performance, and appearance were poor.
Comparative Example 2
[0012]
In Example 1, a fluid transfer heat insulation tube was prepared in the same manner as in Example 1 except that the fluororesin tube and the foamed silicone resin layer were directly extruded without using an intermediate layer made of silicone rubber.
Constriction occurred on the surface of the obtained fluid transfer heat insulation tube, and as shown in FIG. 3, the heat insulation / heat insulation performance was poor and the appearance was poor.
[0014]
Example 4
In Example 1, a metal braided shield made of nickel-plated annealed copper wire is attached to a fluororesin tube, and this metal braided shield is bonded to a silicone rubber intermediate layer with a silicone rubber adhesive (Toshiba Silicone Corp. TSE322RTV). A braided shield layer was provided on the inner surface of the layer.
The obtained fluid transfer heat retaining tube has the same heat insulation, heat retaining performance and appearance as in Example 1, and the terminal treatment is easy (however, it takes a little time to remove the braided shield), and It was excellent in pressure resistance.
[0015]
【The invention's effect】
According to the present invention, a long fluid transfer heat insulation tube can be obtained by using extrusion coating or the like, and the foamed resin / rubber heat insulation layer and the intermediate layer are bonded to each other. Because it is fixed to the resin tube, even if the foamed resin / rubber insulation layer that has been coated with extrusion tries to extend in the longitudinal direction during vulcanization, the expansion is prevented, resulting from stick-slip on the surface of the resin tube As shown in FIG. 2, the surface of the foamed resin / rubber heat insulation layer becomes flat, the heat insulation and heat insulation performance are not deteriorated, and a fluid transfer heat insulation tube having a good appearance can be obtained.
Furthermore, since the foamed resin / rubber insulation layer is not bonded to the resin tube via the intermediate layer, the foamed resin / rubber insulation layer can be easily peeled off from the resin tube when connecting the tube with a joint or the like. Thus, so-called terminal processing becomes easy, and workability during use is remarkably improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a fluid transfer heat insulation tube of the present invention.
FIG. 2 is a longitudinal sectional view showing an example of a fluid transfer heat retaining tube of the present invention.
FIG. 3 is a longitudinal sectional view showing an example of a conventional fluid transfer heat insulation tube.
[Explanation of symbols]
1 Resin tube 2 Foamed resin / rubber insulation layer 3 Intermediate layer

Claims (3)

In the fluid transfer heat insulating tube in which the outer surface of the fluororesin tube is coated with a foamed silicone resin / rubber heat insulating layer, the fluororesin tube is different from the fluorine resin tube between the fluororesin tube and the foamed silicone resin / rubber heat insulating layer. It is characterized by having an intermediate layer made of silicone rubber which is not adhesive to the resin tube and is the same type as the foamed silicone resin / rubber heat insulating layer and has adhesiveness to the foamed silicone resin / rubber heat insulating layer. Fluid transfer heat insulation tube. The fluid transfer heat retaining tube according to claim 1, wherein the intermediate layer is a silicone rubber coating layer. The fluid transfer heat retaining tube according to claim 1 or 2, wherein the outer surface of the intermediate layer is coated with the foamed silicone resin / rubber heat retaining layer and then vulcanized.

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