JP3203984B2 - piping material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to indoor piping such as kitchen piping,
The present invention relates to a piping material having excellent heat resistance, flame retardancy, and aesthetic appearance suitable for outdoor piping, buried piping, and the like.

[0002]

2. Description of the Related Art Heretofore, indoor pipes have been made of vinyl chloride-coated steel pipes or galvanized metal pipes in order to satisfy the fire protection section penetration conditions. In particular, galvanized steel pipes are used for kitchens so that they are heat-resistant, flame-retardant, and do not generate toxic and corrosive gases in a fire.

[0003] A vinyl chloride-coated steel pipe or a galvanized steel pipe is also used for outdoor piping in order to ensure corrosion resistance. In addition, since a long-term durability is particularly required for the underground portion, a resin-coated steel pipe such as polyethylene is used.

[0004]

The galvanized steel pipe used as a piping material for which heat resistance is required, such as a kitchen pipe, has a single color tone, and color unevenness easily occurs due to rust generated by sacrificial corrosion protection. There is a problem.

[0005] Therefore, as a piping material having a more beautiful appearance, a polyvinyl chloride-coated steel pipe in which the outer peripheral surface is coated with vinyl chloride and a polyethylene-coated steel pipe in which the outer peripheral surface is coated with polyethylene have been developed.

However, a steel pipe coated with vinyl chloride on its outer surface has a problem that it deteriorates when used for a kitchen because the heat resistance temperature of vinyl chloride is low. There is also a problem that toxic and corrosive gases are generated during a fire. Similarly, a steel pipe whose outer surface is coated with polyethylene cannot be used for a kitchen because it has a low heat-resistant temperature and has no self-extinguishing property.

[0007] Recently, there has been an increasing need to unify different coated steel pipes used for kitchens, indoors, outdoors, and buried parts because of simplification of workability and improvement of workability. In that case, the performance required for the kitchen is the standard as the performance required for the piping. However, since the kitchen piping is locally heated to a high temperature, the coating resin is required to have a heat resistance of 120C to 150C. In addition, it is required to satisfy the fire compartment penetration condition, and it is required not to generate toxic and corrosive gas during combustion. Piping materials that meet this need have not yet been developed.

The present invention has been made to solve the above problems, and has good heat resistance, flame retardancy, weather resistance, and aesthetic appearance commonly used for kitchens, indoors, outdoors, and buried parts. The purpose is to provide simple piping materials.

[0009]

As a result of the study of the present inventors, a resin-coated steel pipe having a polypropylene containing a flame retardant as an outer layer and a water-resistant adhesive polyolefin as an adhesive layer solves the above-mentioned problems. I found something to do.

[0010] Polypropylene is particularly excellent in heat resistance as compared with other general-purpose resins such as polyethylene and vinyl chloride.
Withstands use at 0 ° C. The viscosity characteristic is shear rate 1.0 × 1
The melt viscosity is 6.0 × 10 ^{1 to} 1.0 × 10 ² (l / sec).
Those having a range of 10 ^{3 to} 5.0 × 10 ⁵ (poise) are preferable. The use of a material having such a range can provide high corrosion resistance and is preferable in terms of extrusion coating.

The type of flame retardant is not limited, but a non-halogen type flame retardant is preferred in that no toxic gas or corrosive gas is generated during combustion. Non-halogen-based ones include nitrogen-based flame retardants, phosphorus-based flame retardants, inorganic flame retardants and the like, all of which do not contain halogen. Examples of nitrogen-based flame retardants include guanidine sulfamate, and examples of phosphorus-based flame retardants include tricresyl phosphate, triethyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, and inorganic flame retardants. Examples include red phosphorus, tin oxide, antimony trioxide, zirconium hydroxide, barium metaborate, aluminum hydroxide, magnesium hydroxide and the like. Of these, inorganic flame retardants are particularly preferred, and among them, magnesium hydroxide and aluminum hydroxide are most preferred. The amount of the flame retardant added is about 0.1 to 60% by weight,
It is preferably about 5 to 60% by weight, particularly preferably 10 to 60% by weight.
About 60% by weight is appropriate.

The coating based on nylon 6 includes a coloring agent for coloring as long as its performance is not impaired, and if necessary, glass, glass fiber, carbon fiber, silica, alumina, calcium carbonate, graphite, Additives such as inorganic fillers such as molybdenum disulfide, modifiers, dispersants, leveling agents, anti-settling agents, antioxidants, and ultraviolet absorbers can be added. In addition, a release oil or a fluororesin can be added to prevent contamination on the surface.

In any case, the resin coating layer must contain at least 40% by weight of polypropylene.

The coating thickness is 0.1 to 5 mm, preferably 0.2 to 3.0 mm, particularly preferably 0.5 to 2.
0 mm is appropriate. If the coating film thickness is less than 0.1 mm, the anticorrosion performance becomes insufficient, while if the coating thickness is more than 5 mm, it is not economical.

[0015] The method of coating the steel pipe can be an extrusion coating method, a powder coating method, a coating method of forming a coating, and the like. The resin can be formed into a coating by dispersing or dissolving the resin in water or a solvent. As a coating method of forming a coating, usual means such as spray coating, spatula coating, brush coating, roller coating, and sword coating can be used. The preferred method is extrusion coating.

A water-resistant adhesive polyolefin layer is provided as an outer adhesive layer comprising the above-mentioned polypropylene as a base material. Adhesive polyolefin having water resistance has the property of adhering polypropylene and steel pipe, for example, adhesive polyolefin, particularly maleic acid, maleic anhydride, polyethylene modified with acrylic acid, etc.
For example, polypropylene.

The thickness of the adhesive layer is 10 to 1000 μm.
m, preferably 20 to 500 μm, particularly preferably 30 μm.
About 100 μm is appropriate.

A primer can be used to improve the adhesion between the steel pipe and the adhesive layer. This primer has good adhesiveness to both the steel pipe surface and the adhesive layer, and a primer such as epoxy, cyanoacrylate, silicone, or polyimide is suitable. Primer layer thickness is 5
It may be about 300 μm, preferably about 10 to 50 μm.

A metal coating can be used on the outer peripheral surface of the steel pipe to improve the adhesion between the steel pipe and the adhesive layer or the primer or to improve the corrosion resistance. The metal coating is not particularly limited, but galvanization is particularly preferable in that high corrosion protection performance can be obtained. The coating method is not particularly limited, but a plating method, a thermal spraying method, or the like is preferable. In addition, one or more of blasting, pickling, degreasing, chemical conversion (such as chromate treatment) and the like can be performed using the metal-coated surface or the steel tube surface as a pretreatment.

[0020]

【Example】

Examples 1 to 3 and Comparative Examples 1 to 3 Each coating layer was formed on 25A SGP under the conditions shown in Table 1 to produce a resin-coated steel pipe.

[0021]

[Table 1] Admer; Adhesive polyolefin N-polymer manufactured by Mitsui Petrochemical; Adhesive polyolefin manufactured by Nippon Petrochemical

Table 2 shows the results of measuring the performance of each of the above resin-coated steel pipes.

[0023]

[Table 2]

3. Measurement method Fire penetration section penetration conditions; Japan Building Center's section penetration section construction method technical committee evaluation application guidelines According to the fire resistance test method for water supply and drainage pipes. Whether or not the steel pipe can be coated: When extruded on a steel pipe, the resin is determined to be able to be coated if the resin is not adhered to the steel pipe without detaching or non-uniformly adhering to the steel pipe due to the resin being cut or dripping by its own weight. I do. Initial adhesive strength; JIS G 3364-86 SST peeling distance; JIS Z 2371 The measuring method is to put a slit in the coating resin, and let the length of the part to be peeled off without adhesive resistance be the peeling distance.

[0025]

The resin-coated steel pipe of the present invention has a high heat-resistant temperature and is flame-retardant, so that it can meet the fire compartment penetration conditions required for kitchen use. Furthermore, since it can be used for outdoor use and burying, one type of coated steel pipe of the present invention can be used. A piping material having excellent heat resistance, flame retardancy, weather resistance and aesthetic appearance can be provided. Further, since the coating resin has excellent adhesion to the steel pipe, rust of the steel pipe is suppressed.

Continuation of the front page (72) Inventor Mitsuki Yasuhara 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Kokan Co., Ltd. (56) References JP-A-59-91055 (JP, A) JP-A-60-244539 ( JP, A) JP-A-64-24872 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05D 1/00-7/26 B32B 15/08 103

Claims (3)

(57) [Claims] 1. A resin-coated steel pipe for kitchen piping or indoor piping in which a polypropylene containing a flame retardant is used as an outer layer, and the outer layer is coated via an adhesive layer made of a water-resistant adhesive polyolefin. 2. A resin-coated steel pipe in which a polypropylene containing a flame retardant is used as an outer layer and the outer layer is coated via an adhesive layer made of a water-resistant adhesive polyolefin, wherein the melt viscosity of the polypropylene is a shear rate. 1 × 10 ¹
6 × ¹⁰ in the range of ~10 ² sec ^-1 3 ~5 × 1
Resin-coated steel pipe in the range of 0 ⁵ poise 3. The flame retardant is a non-halogen flame retardant,
The amount of the additive is 0.1 to 60 wt%.
Resin-coated steel pipe for kitchen piping or indoor piping as described