JPH0549874B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to synthetic resin pipes whose outer peripheral surfaces are coated with nonflammable inorganic materials and their joints, which are mainly used for indoor water supply and distribution pipes in buildings, etc., and are particularly useful in the event of a fire. The present invention relates to fire-resistant synthetic resin pipes and fittings that are effective in preventing the spread of fire to other floors via spaces for water supply and drainage pipes. [Conventional technology] In the past, iron pipes were mainly used for water supply and drainage in buildings, but in recent years synthetic pipes mainly made of vinyl chloride have been used because they are susceptible to corrosion, leak easily, are heavy, and are cumbersome to install. Resin pipes have come to be mainly used. However, synthetic resin lacks heat resistance, and in the event of a fire, even if fire doors are in place, it is inevitable that the fire will spread to other floors through the piping space, so the water supply and drainage pipes themselves are made incombustible. . This non-combustibility is achieved by coating the outer peripheral surface of the synthetic resin pipe with a hydraulic inorganic material and hardening it. At this time, materials mainly made of cement and asbestos were used as the hydraulic inorganic material. . [Problems to be Solved by the Invention] Asbestos is used as a reinforcing material for cement, and many products are commercially available. This is because asbestos has properties that are comprehensively balanced compared to other fibers, such as pulp and alkali-resistant glass fiber, in terms of nonflammability, water retention, miscibility with cement, ability to capture cement, price, etc. This is because However, in recent years, asbestos has attracted international attention as a carcinogen, and its use has already been banned in the United States. In this situation, the present invention aims to provide fire-resistant synthetic resin pipes and joints that do not contain asbestos, which is harmful to the human body, are easier to manufacture, and have comparable quality, price, and performance compared to asbestos-containing products. The purpose is to develop. [Means for Solving the Problems] The present invention is inexpensive, and even if the internal synthetic resin pipe melts or burns out and becomes incapable of changing shape during a fire, the hydraulic inorganic material can be The purpose of the present invention is to provide a fire-resistant synthetic resin pipe and a joint therefor, which has the strength to prevent the spread of fire by maintaining its shape, is lightweight and easy to construct. That is, in fire-resistant synthetic resin pipes and their joints whose outer circumferential surface is coated with a hydraulic inorganic material, the hydraulic inorganic material is 15 to 45 parts by weight of silica sand and 30 to 45 parts by weight of lightweight aggregate to 100 parts by weight of cement. This is a fire-resistant synthetic resin pipe and its joint made of 80 parts by weight, 2 to 10 parts by weight of organic fibers, and 1 to 5 parts by weight of a thickener. The present invention also provides a method for manufacturing a fire-resistant synthetic resin pipe or a joint thereof whose outer peripheral surface is coated with a hydraulic inorganic material, in which the hydraulic inorganic material is cement.
A mortar containing 15 to 45 parts by weight of silica sand, 30 to 80 parts by weight of lightweight aggregate, 2 to 10 parts by weight of organic fiber, 1 to 5 parts by weight of thickener, and 25 to 40 parts by weight of water per 100 parts by weight. This is a method for manufacturing a fire-resistant synthetic resin pipe and its joint, which is characterized by press-fitting the pipe into a mold in which the synthetic resin pipe or its joint has been set, and quickly removing it from the mold. The synthetic resin pipes and joints used here are usually hard vinyl chloride pipes, but may be made of other thermoplastic resins such as polypropylene and polyethylene, and are not particularly limited. Among hydraulic inorganic materials, cement may be any self-hardening cement that hardens by reacting with water, such as ordinary Portland cement, white cement, early strength cement, etc., depending on the purpose, for example, where high whiteness is desired. Depending on the purpose, white cement is used for piping, and early-strength cement is used where early hardening is required. Usually, inexpensive Portland cement is sufficient. Silica sand is added to improve fire resistance. The mixing ratio is 15 to 45 parts by weight per 100 parts by weight of cement. If it is less than 15 parts by weight, it is not critical, but the fire resistance (heat resistance) of the entire inorganic material will decrease. On the other hand, if the amount exceeds 45 parts by weight, the overall mechanical strength will decrease, so the amount should be within this range. Lightweight aggregate is a fired product of artificial lightweight aggregate such as obsidian, nacre, vermiculite, etc., and is as light as possible, has high strength, has a spherical and smooth surface, and has a uniform particle size. , those with low water absorption, such as Fuyolite (Fuyolite Co., Ltd.) are preferred. In the present invention, it is also added for the purpose of lowering the specific gravity of the inorganic material and blocking heat, but if the amount is 30 to 80 parts by weight per 100 parts by weight of cement, and the amount is too small, the heat resistance and weight reduction will be insufficient. If the amount is too large, the strength of the inorganic material itself will be reduced. Organic fibers are added for reinforcement purposes. It is preferably 2 to 10 parts by weight per 100 parts by weight of cement.
Target materials include various pulps such as linters, groundwood pulp, and kraft pulp, and various synthetic fibers such as nylon, polyester, vinylon, polyethylene, and polypropylene. The type and fiber length are selected in consideration of strength, impact resistance, compatibility with cement, etc., but the thickness is preferably 15 deniers or less, and the length is generally 1 mm or more, but this is not critical. Thickeners are added for the purpose of demolding immediately after covering synthetic resin pipes with mortar and to improve moldability such as lubricity and bonding properties. Add up to 5 parts by weight. This remains in the hydraulic inorganic material after curing, but has no effect. There are no particular restrictions on the thickener, but ethyl cellulose modified from cellulose,
CMC, water-soluble cellulose derivatives, saponified vinyl acetate, sodium alginate, etc. can be used. In order to remove the mold immediately after filling the mold, which is one of the features of the present invention, it is necessary to incorporate the above-mentioned thickener, but the ratio of the amount of water added to the hydraulic inorganic material is extremely important. That is, in a normal case, 70 parts or more of water is mixed with 100 parts by weight of cement, but this is extremely reduced to 25 to 40 parts for demolding immediately after filling. Therefore, there is no need to prepare a large number of molds for molding, as is the case in the usual case. Because the viscosity of the mortar is extremely high, it is necessary to press it in using an extruder, but one or two molds are required at each stage for press-fitting, moving, demolding, cleaning, applying release agent, and moving. There is no need to use a mold for curing, just preparation. Furthermore, reducing the amount of added water is extremely advantageous because it ensures uniform high strength of the hydraulic inorganic material after curing. Uncured coated pipe or fittings after stripping:
High temperature (60~80℃), high humidity (80~80℃ relative humidity)
It is more suitable to grow under 100RH%). The organic matter (total of organic fibers and thickener) contained in this hydraulic inorganic material is preferably 5% by weight or less in order to maintain heat resistance. Furthermore, depending on the purpose, it is of course possible to use a dispersant (water reducer) such as Melment, a coloring agent, a hardening agent, a retarder, a waterproofing agent, a water repellent, etc. in combination. The thickness of the hydraulic inorganic material coated varies depending on the diameter of the synthetic resin pipe used, but it is usually 7 to 12 mm, taking into consideration fire resistance and strength after the synthetic resin pipe is burned out. The desired thickness is selected. [Function] Since the surface of the corrosion-resistant synthetic resin pipe and its joint according to the present invention is covered with a thick hydraulic inorganic material, no toxic gas is generated even in the event of a building fire.
In addition, even if the internal synthetic resin pipe melts or burns out, its external shape can be maintained, so the spread of fire through the space of the water supply and drainage pipes can be prevented. Furthermore, when manufacturing fire-resistant synthetic resin pipes or their joints by the method of the present invention, there is no need to prepare a large number of expensive molds, and the products can be manufactured with high productivity, and the resulting products have low water consumption. Because it is a mixed mortar, fire-resistant synthetic resin pipes with a high-strength coating can be obtained. [Example] Hereinafter, the present invention will be specifically explained with reference to Examples. Example 1 Hydraulic inorganic material Portland cement 52.4% by weight, white silica sand
16.7% by weight, lightweight lubricant (expanded obsidian, trade name Fuyolite; Fuyolite Co., Ltd.) 27.3%, pulp 2.0
Weight%, vinylon fiber (15mm length) 0.6% by weight, cellulose derivative (Himetrose; Shin-Etsu Chemical)
1.0% by weight was put into a mixer and made into mortar at a water ratio of 29.5. Filling A vinyl chloride pipe fitting (nominal diameter DL75) is placed in a half mold (clearance approximately 9 mm), and the above inorganic material mortar extruded in a ring shape into the space between the mold and the fitting is filled with a screw-type filling machine. Press-fitted. The inner surface of the mold was previously coated with a release agent to improve releasability. After press-fitting, the mold is opened, the joint coated with the hydraulic inorganic material is taken out from the mold, and the joint is steam-cured. The specific gravity of the inorganic material of this joint was 1.3. Comparative Example 1 Hydraulic inorganic materials Ordinary Portland cement 52.4% by weight, white silica sand 16.7% by weight, lightweight aggregate (same as Example) 17.9%
The mortar had a pulp content of 10.0% by weight, vinylon fiber 2.0% by weight, Hymetrose 1.0% by weight, and a water ratio of 29.5%. The filling was the same as in Example 1, and the specific gravity of the obtained inorganic material was 1.2. Fire resistance test The joints of synthetic resin pipes coated with the hydraulic inorganic material obtained in Example 1 and Comparative Example 1 (however, vinyl chloride was exposed at the opening of the joints) were tested.
Heat to 1010℃ based on JIS A 1304. As a result, the vinyl chloride joint burned, leaving behind a coating of hydraulic inorganic material. Although fine cracks were observed in the coating of Example 1, the shape was firm;
It was recognized that the fire was sufficiently prevented from spreading. On the other hand, the coating of the comparative example has a composition that excludes organic fibers that are considered to have a negative effect on fire resistance (however, the lightweight aggregate was 82.3 parts by weight for 100 parts by weight of cement).
(parts by weight), fine cracks were observed on the entire surface of the coating, and the coating material was split into two, indicating a problem. Example 2 For the purpose of examining the effect of silica sand, 100 parts by weight of Portland cement and 50 parts by weight of lightweight aggregate (same as Example 1) were used.
parts by weight, 2 parts by weight of linter pulp, 2 parts by weight of cellulose derivative (same as in Example 1), and the water ratio of 30, and by changing the blending amount of silica sand.
DL75) and steam-cured. This coating was tested with the following results.

[Table] [Effects of the invention] This fire-resistant synthetic resin pipe and its fittings do not use asbestos, which is harmful to the human body, and can be supplied using the same manufacturing method as before. It has become possible to create water supply and drainage piping that is free from adhesion and is effective in preventing the spread of fire even in the event of a building fire.

Claims (1)

[Scope of Claims] 1. A fire-resistant synthetic resin pipe or a joint thereof whose outer peripheral surface is coated with a hydraulic inorganic material,
The hydraulic inorganic material is based on 100 parts by weight of cement.
A fire-resistant synthetic resin pipe and its joint, characterized by comprising 15 to 45 parts by weight of silica sand, 30 to 80 parts by weight of lightweight aggregate, 2 to 10 parts by weight of organic fiber, and 1 to 5 parts by weight of a thickener. 2. The fire-resistant synthetic resin pipe and its joint according to claim 1, wherein the total amount of organic substances such as organic fibers and thickeners contained in the hydraulic inorganic material is 5% by weight or less in the inorganic material. . 3. In the manufacturing method of fire-resistant synthetic resin pipes or joints thereof whose outer peripheral surface is coated with a hydraulic inorganic material, the hydraulic inorganic material is 15 to 45 parts by weight of silica sand and lightweight bone per 100 parts by weight of cement. Material 30~80
Parts by weight, 2 to 10 parts by weight of organic fiber, 1 to 5 parts by weight of thickener
A fire-resistant synthetic resin pipe, which is characterized in that a mortar containing 25 to 40 parts by weight of water and 25 to 40 parts by weight of a fire-resistant synthetic resin pipe is press-fitted into a mold in which a synthetic resin pipe or a joint thereof is set, and the mold is quickly removed. Manufacturing method for fittings.