Resin tube
By integrating negative thermal expansion materials into the resin layer of resin pipes, the issue of deformation and expansion due to temperature increases is addressed, resulting in a more stable and reliable pipe structure.
Patent Information
- Application Number
- JP2023175180
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-10-10
- Publication Date
- 2025-04-22
AI Technical Summary
Resin pipes are prone to deformation such as deflection when temperatures rise, making them easily expandable and potentially leading to pressure loss and structural instability.
Incorporating negative thermal expansion materials, which can be granular, into the resin layer of the pipe to suppress overall linear expansion and volume changes as temperature increases.
The resin pipe becomes difficult to expand, maintaining structural integrity and reducing pressure loss, even in high-temperature environments, thus enhancing its reliability and application flexibility.
Smart Images
Figure 2025065758000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a resin pipe. [Background technology]
[0002] It has been proposed to improve the strength of resin pipes by blending whiskers containing boehmite or zinc oxide, or flaky clay minerals such as mica or talc, as reinforcing materials into the resin (see, for example, Patent Document 1). [Prior art documents] [Patent documents]
[0003] [Patent Document 1] JP 2022-155930 A Summary of the Invention [Problem to be solved by the invention]
[0004] Resin pipes are required to be resistant to expansion even when the temperature rises, since this can cause deformation such as bending.
[0005] The present invention has been proposed in view of the above problems associated with the conventional technology, in order to preferably solve these problems, and has an object to provide a resin pipe that is less likely to expand. [Means for solving the problem]
[0006] A first aspect of the resin pipe according to the present invention is as follows: The present invention relates to a negative thermal expansion material.
[0007] A second aspect of the resin pipe according to the present invention is the same as the first aspect, The negative thermal expansion material may be in granular form. Effect of the Invention
[0008] The resin pipe according to the present invention is less likely to expand. [Brief description of the drawings]
[0009] [Figure 1] FIG. 1 is a perspective view showing a resin pipe according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] Next, the resin pipe according to the present invention will be described below by way of preferred examples with reference to the accompanying drawings. Note that the embodiments and drawings described below are merely examples of the present invention, and are not intended to limit the present invention to these configurations, and may be modified as appropriate without departing from the scope of the present invention. EXAMPLES
[0011] The resin pipe 10 (see FIG. 1) according to the embodiment contains a negative thermal expansion material. More specifically, the resin pipe 10 includes a resin layer and a negative thermal expansion material contained in the resin layer. The resin pipe 10 can be used, for example, as piping for water supply, drainage, air conditioning, etc., and is not limited to the above-mentioned uses. In addition, the fluid passed through the resin pipe 10 is not limited to air or water, but may be other fluids such as gas, steam, oil, etc. The resin pipe 10 may be a single-layer pipe or a multi-layer pipe composed of multiple layers. In the case of a multi-layer pipe, it is sufficient that at least one resin layer contains a negative thermal expansion material.
[0012] Examples of the resin that can be used to form the resin layer include polyolefin resins such as vinyl chloride, polyethylene, polypropylene, and polybutene, polycarbonate, acrylic resin, fluororesin, and polyamide resin, either alone or as a polymer alloy.
[0013] A negative thermal expansion material is a material that exhibits negative thermal expansion, which means that its volume decreases as the temperature increases. Examples of negative thermal expansion materials include β-eucryptite (LiAlSiO4), zirconium tungstate (ZrW2O8), zirconium tungstate phosphate (Zr2WO4(PO4)2), Zn x CD 1-x(CN)2, Manganese nitride, Bismuth-nickel-iron oxide, Bismuth-nickel oxide (Bi 0.95 La 0.05 NiO3), scandium fluoride (ScF3), ruthenium oxide (Ca2RuO4), lead vanadium oxide (Pb 0.76 La 0.04 Bi 0.20 Examples of oxides that can be used include Cu2V2O7-based oxides such as VO3, zinc pyrophosphate (Zn2P2O7), magnesium pyrophosphate (Mg2P2O7), and α-Cu2V2O7.
[0014] As the Cu2V2O7-based oxide, if a part of the Cu site or V site is replaced with another element, the linear expansion coefficient is preferably a negative linear expansion coefficient with a large absolute value of -10 (ppm / K) or less. 2-x R x V2O7 (R is at least one element selected from Ga and Fe), Cu2V 2-x Mo x O7 is an example.
[0015] The shape of the negative thermal expansion material is not particularly limited, but may be, for example, granular. It is considered that a granular negative thermal expansion material is less likely to be exposed on the surface of the resin pipe 10 than a fibrous fuller. In this way, if the negative thermal expansion material is not exposed on the surface of the resin pipe 10, for example, a lining process for forming a coating on the inner surface of the resin pipe 10 can be omitted, making it easier to form the resin pipe 10 in a single layer.
[0016] In addition to the resin and negative thermal expansion material that constitute the resin layer, the resin pipe 10 may contain other components such as fiber materials such as carbon fiber and glass fiber, needle-shaped crystals such as alumina and zinc oxide, compatibilizers, stabilizers, stabilization aids, lubricants, processing aids, impact modifiers, heat resistance improvers, antioxidants, ultraviolet absorbers, light stabilizers, fillers, pigments, plasticizers, etc. The other components may be used alone or in combination of two or more.
[0017] The resin pipe 10 can be manufactured by a known molding method such as extrusion molding, injection molding, and blow molding. For example, when manufacturing the resin pipe 10 by extrusion molding, pellets formed separately by kneading resin and a negative thermal expansion material are heated and melted, the molten resin is passed through a die to form a cylindrical shape, and then cooled to obtain the resin pipe 10. Alternatively, the resin pipe 10 can be obtained by heating and melting a mixture of a resin material and a negative thermal expansion material mixed in a hopper, passing the molten resin through a die to form a cylindrical shape, and then cooling.
[0018] Since the resin pipe 10 contains a negative thermal expansion material, the volume of the negative thermal expansion material decreases even when the temperature rises, so that the linear expansion of the entire pipe can be suppressed. In this way, the resin pipe 10 is unlikely to expand even when the temperature rises due to the usage environment or the fluid flowing therethrough, and the change in length and volume can be suppressed. And, since the resin pipe 10 is unlikely to expand, the pressure loss of the fluid flowing inside can be avoided. Therefore, the resin pipe 10 can be used in a high-temperature usage environment or with a high-temperature fluid, and can be applied even in cases where a relatively high reliability is required, such as factory piping and firefighting piping, and has a high degree of freedom in use. In addition, since the resin pipe 10 is unlikely to deform, the number of supports can be reduced, and workability can be improved. [Explanation of symbols]
[0019] 10 Plastic pipe
Claims
1. A plastic pipe containing a negative thermal expansion material.
2. The resin pipe according to claim 1 , wherein the negative thermal expansion material is in a granular form.
Citation Information
Patent Citations
Resin pipe
JP2022155930A