JP2001324063A - Synthetic resin pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin pipe capable of coloring according to a purpose and a function at a low cost and imparting a specified function to a colored layer itself. SOLUTION: The colored layer with thickness of about 0.1-0.2 mm or of 20% of overall thickness (wall thickness) of a pipe is integrally provided on an outer circumference of the synthetic resin pipe. A colored line in an axial direction of the pipe is also integrally provided on the outer circumference of the synthetic resin pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin pipe, and more particularly, to a colored synthetic resin pipe for obtaining a light-shielding property or a color for each application.

[0002]

2. Description of the Related Art For example, synthetic resin pipes for gas are colored yellow, and synthetic resin pipes for water are colored blue.
Synthetic resin tubes colored by mixing additives for obtaining light-shielding properties and thermal stability are widely distributed, including synthetic resin tubes colored according to the color of the construction site.

[0003]

However, conventionally, expensive pigments and additives have been mixed into the resin (natural resin) forming the synthetic resin tube, and the entire tube has been colored. This had a significant effect on the cost of the synthetic resin tube.

[0004] Therefore, an object of the present invention is to provide a synthetic resin tube which can perform coloring by use or function at low cost and can impart a specific function to the colored layer itself.

[0005]

In order to achieve the above object, a first structure of the synthetic resin pipe of the present invention is that a colored layer having a thickness of about 0.1 to 0.2 mm is provided on the outer periphery of the synthetic resin pipe. Is provided integrally. Further, the second configuration of the synthetic resin pipe of the present invention is characterized in that a colored layer having a thickness of about 20% of the entire thickness (wall thickness) of the pipe is integrally provided on the outer periphery of the synthetic resin pipe. Further, a third configuration of the synthetic resin tube of the present invention is characterized in that a colored line in the tube axis direction is integrally provided on the outer periphery of the synthetic resin tube.

[0006]

1 and 2 show a first embodiment of a synthetic resin pipe according to the present invention. FIG. 1 is a front view in an end face direction, and FIG. 2 is a sectional side view. This synthetic resin tube is integrally formed in a two-layer structure of an inner layer 11 made of a natural resin and an outer layer 12 made of a color compound.
The outer layer 12 is formed as an extremely thin layer having a thickness T of about 0.1 to 0.2 mm. The color tone and the resin composition of the outer layer 12 can be arbitrarily selected according to the use, function, and the like.
For example, the color may be yellow for gas and blue for water.

As described above, by forming a thin colored layer as the outer layer 12, the amount of the coloring pigment used in the colored synthetic resin tube can be reduced, so that the manufacturing cost of the colored synthetic resin tube can be reduced. When the joining strength is reduced by the oxide film on the joining surface, such as in the case where the polyethylene pipe and the electric fusion joint are joined by fusion, the joining surface is scraped in advance before the joining to remove the oxide film. Although it is necessary, by scraping to the extent that the inner layer 11 is exposed, the completion of the scraping can be known by the presence or absence of the outer layer 12, and the oxide film can be reliably removed.

Further, the thickness of the outer layer 12 is set to 0.1 to 0.5.
By setting the thickness to about 2 mm, the oxide film can be sufficiently removed with the minimum scraping amount, and excessive scraping can be prevented. Therefore, it is possible to eliminate the individual differences in the scrape and to standardize the scrape amount.

FIG. 3 is a sectional side view showing a second embodiment of the synthetic resin pipe of the present invention. This synthetic resin pipe is integrally formed in a two-layer structure of an inner layer 11 made of a natural resin and an outer layer 12 made of a color compound, as in the first embodiment, but the thickness T of the outer layer 12 is reduced. , Is set to about 20% of the total thickness (wall thickness) of the pipe.

According to the current standard, when a tube has a flaw exceeding 20% of its wall thickness, the portion is cut off so as not to be used, but the thickness of the colored outer layer 12 is reduced to 20% of the wall thickness. %, It is easy to know that the depth of the flaw exceeds 20% of the wall thickness when the color of the inner layer 11 is observed inside by observing the flaw generated in the synthetic resin pipe. be able to. That is, the quality of the synthetic resin tube can be easily determined only by visually observing the damaged portion where the scratch has occurred.

As shown in these embodiments, when the entire outer periphery of the tube is covered with a colored outer layer 12, the outer layer 12 may be made of a hindered amine based resin in addition to a colored resin obtained by mixing a coloring pigment with a natural resin. It is also possible to use a colored resin obtained by mixing a natural resin with a weathering agent such as a light stabilizer (HALS) or a benzotriazole-based ultraviolet absorber, or a heat-resistant agent such as a phenolic antioxidant or a phosphoric acid-based antioxidant. .

FIG. 4 is a perspective view showing a third embodiment of the synthetic resin tube of the present invention. This synthetic resin tube has a colored line 22 made of a color compound integrally provided on the outer periphery of a tube body 21 made of a natural resin in the tube axis direction.

The colored line 22 mainly indicates the purpose of use, and a yellow color compound is used for gas and a blue color compound is used for water supply. By displaying the application using such a colored line 22, the amount of expensive pigment used can be significantly reduced. Such a colored line 22
The width and thickness (depth) of can be appropriately set according to the diameter and thickness of the pipe, and may be selected in consideration of visibility and cost. The number of the colored lines 22 is not limited to one, and two or more colored lines may be provided in consideration of handleability, visibility, and the like.

Incidentally, the synthetic resin pipe shown in each embodiment can be easily integrally formed by two-color extrusion, without impairing the productivity.

[0015]

As described above, according to the synthetic resin pipe of the present invention, not only the cost required for coloring can be reduced, but also the scraping operation and the confirmation of damage can be facilitated.

[Brief description of the drawings]

FIG. 1 is a front view in an end face direction showing a first embodiment of a synthetic resin tube of the present invention.

FIG. 2 is also a side view.

FIG. 3 is a sectional side view showing a second embodiment of the synthetic resin tube of the present invention.

FIG. 4 is a perspective view showing a third embodiment of the synthetic resin tube of the present invention.

[Explanation of symbols]

 11 inner layer, 12 outer layer, 21 pipe body, 22 colored line

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yuji Amihara 2480 Maido, Hiratsuka-shi, Kanagawa F-term in the Hiratsuka Plant of Mitsubishi Plastics Co., Ltd. (Reference) 3H111 AA01 BA15 CB02 CB03 CB23 CB29 DA21 DA26 DB11 4F100 AK01A AR00B BA02 BA25 DA11 DC21B DD09B GB07 GB90 JL05 JL10B JN02B YY00B

Claims (3)

[Claims] The thickness of the synthetic resin tube is 0.1 to 0.1 mm.
A synthetic resin tube having a colored layer of about 0.2 mm provided integrally. 2. The outer circumference of the synthetic resin pipe has a thickness of 2
A synthetic resin pipe characterized in that a coloring layer of about 0% is provided integrally. 3. A synthetic resin tube, wherein a colored line in the axial direction of the tube is integrally provided on the outer periphery of the synthetic resin tube.