JP2009057995A - Resin lining steel pipe and drain pipe structure using resin lining steel pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin lining steel pipe excellent in sound insulation properties and construction properties, and sufficiently retarding flame and heat generated in a lower floor to path through an inside of a collecting joint connected and to reach a horizontal branch pipe connected to a horizontal branch pipe connection part when the same is used as a vertical pipe, and also to provide a drain pipe structure using the resin lining steel pipe. <P>SOLUTION: The resin lining steel pipe 1 provided with a resin lining layer 12 on an inner surface is provided with at least a tubular fire resistant expansion layer 12a comprising fire resistant thermally expandable resin composition. The resin lining layer 12 has a single layer structure of a fire resistant expansion layer comprising the fire resistant thermally expandable resin composition containing 1-10 pts.wt. thermally expandable graphite per 100 pts.wt. of polyvinyl chloride resin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resin-lined steel pipe and a drain piping structure using the resin-lined steel pipe.

  Conventionally, there is a structure that allows piping means to pass through various sections such as a floor that partitions an upper layer and a lower layer in a multi-layered building and a wall that partitions adjacent spaces (Patent Document 1). In the case where such a partition penetrating portion is a fire prevention section, a structure is required so that when a fire occurs in one space partitioned by the section, the flame does not enter the other space.

  That is, when a water supply pipe, distribution pipe or other pipe penetrates a floor or wall of a fireproof structure, the gap between the pipe and the fireproof section of a semi-fireproof structure must be filled with mortar or other nonflammable material. In addition, it is supposed that the parts that pass through distribution pipes and other pipes and the parts that are within a distance of 1 m on each side from the penetrating parts are made of non-combustible materials (see the Building Standards Law Enforcement Ordinance).

  Therefore, in the penetration part of the floor slab which is a fire prevention section which divides each floor of the multi-layered building, a metal collective joint is used and connected to the vertical pipe connection part and the side branch pipe connection part above and below the collective joint. For the vertical pipe and the horizontal branch pipe, a resin-lined steel pipe having excellent fire resistance, a fire-resistant double-layer pipe (having a fiber-reinforced mortar layer around the resin pipe), a metal pipe, and the like are used.

  However, when a metal pipe is used, there is a problem that it is heavy and has a problem in workability, and is poor in soundproofing effect of drainage sound. On the other hand, in the case of a fireproof two-layer pipe, it is lighter than a metal pipe and has a high soundproofing effect on drainage sound, but there is a problem that the mortar layer breaks, and there is a problem in handling. On the other hand, in the case of resin-lined steel pipes, it is lighter than metal pipes, has high soundproofing of drainage sound, and is easy to handle, but it is expensive compared to resin-only piping materials. There's a problem.

Japanese Patent Laid-Open No. 10-195947

  Therefore, the inventors of the present invention, if the flame and hot air generated in the lower floor can sufficiently delay the passage through the assembly joint and reach the side branch pipe connected to the side branch pipe connection portion. The present invention has been completed as a result of diligent investigations on the possibility that a pipe material made only of resin can be used for the lateral branch pipe, and that the overall cost can be reduced.

  In view of the above circumstances, the present invention is excellent in sound insulation and workability, and when used as a standing pipe, the flame and hot air generated on the lower floor pass through the inside of the collective joint and enter the side branch pipe connecting portion. It is an object of the present invention to provide a resin-lined steel pipe that can sufficiently delay reaching a connected lateral branch pipe and a drainage pipe structure using the resin-lined steel pipe.

  In order to achieve the above object, a resin-lined steel pipe according to the present invention is a resin-lined steel pipe having a resin-lining layer on its inner surface, wherein the resin-lining layer has a tubular fire-resistant expansion layer made of a fire-resistant and heat-expandable resin composition. It is characterized by having at least.

  Although the resin lining pipe of the present invention is not particularly limited, it manufactures a fire-resistant and heat-expandable resin pipe having at least a fire-resistant expansion layer serving as a lining layer, and the outer surface of the resin pipe is manufactured in the same manner as a conventional method for manufacturing a resin lining pipe. And / or by inserting a resin pipe into the steel pipe with an adhesive applied to the inner surface of the steel pipe and reducing the diameter of the steel pipe or expanding the resin pipe to integrate the steel pipe and the resin pipe. Since it is preferable not to heat the fire-resistant and heat-expandable resin pipe so much, it is preferable to reduce the diameter of the steel pipe.

  The main component resin of the resin composition constituting the fire-resistant and heat-expandable resin pipe is not particularly limited, but a polyvinyl chloride resin having self-extinguishing properties is preferable.

  Examples of the polyvinyl chloride resin include: a polyvinyl chloride homopolymer; a copolymer of a vinyl chloride monomer and a monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer; ) A graft copolymer obtained by graft copolymerizing vinyl chloride with a polymer may be used, and these may be used alone or in combination of two or more. Further, the polyvinyl chloride resin may be chlorinated as necessary.

  The monomer having an unsaturated bond copolymerizable with the vinyl chloride monomer is not particularly limited, and examples thereof include α-olefins such as ethylene, propylene, and butylene; vinyl esters such as vinyl acetate and vinyl propionate; butyl Vinyl ethers such as vinyl ether and cetyl vinyl ether; (meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate and butyl acrylate; aromatic vinyls such as styrene and α-methylstyrene; N-phenylmaleimide N-substituted maleimides such as N-cyclohexylmaleimide and the like may be used, and these may be used alone or in combination of two or more.

  The polymer for graft copolymerization with vinyl chloride is not particularly limited as long as it is for graft copolymerization with vinyl chloride. For example, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon monoxide copolymer Polymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate-carbon monoxide copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, acrylonitrile-butadiene copolymer, polyurethane, chlorinated polyethylene, A chlorinated polypropylene etc. are mentioned, These may be used independently and 2 or more types may be used together.

  The average degree of polymerization of the polyvinyl chloride-based resin is not particularly limited. However, when it becomes smaller, the physical properties of the molded body are lowered, and when it becomes larger, the melt viscosity becomes higher and molding becomes difficult. Preferably, 600-1400 is particularly preferable. The average degree of polymerization refers to a resin obtained by dissolving a polyvinyl chloride resin in tetrahydrofuran (THF), removing insoluble components by filtration, and then removing THF in the filtrate by drying. It means the average degree of polymerization measured according to -6721 “Testing method of vinyl chloride resin”.

  The polymerization method of the polyvinyl chloride resin is not particularly limited, and any conventionally known polymerization method may be employed, and examples thereof include a bulk polymerization method, a solution polymerization method, an emulsion polymerization method, and a suspension polymerization method. It is done.

  The method for chlorinating the polyvinyl chloride resin is not particularly limited, and a conventionally known chlorination method may be employed, and examples thereof include a thermal chlorination method and a photochlorination method.

  Any of the above polyvinyl chloride resins may be used after being crosslinked or modified within a range not impairing the fire resistance performance of the resin composition. In this case, a resin that has been cross-linked or modified in advance may be used. When an additive or the like is blended, it may be cross-linked or modified at the same time, or it may be cross-linked or modified after the above components are blended in the resin. . There is no particular limitation on the crosslinking method of the resin, and a conventional crosslinking method of polyvinyl chloride resin, for example, crosslinking using various crosslinking agents, peroxides, crosslinking by electron beam irradiation, water crosslinkable material is used. And the like.

The fire-resistant and heat-expandable resin pipe of the present invention is not particularly limited as long as the fire-resistant expansion layer expands when heated by a flame or the like and can close or close the inside of the tube. Even a single layer having only an expanded layer has a multilayer structure in which a resin layer made of a resin composition not containing expanded graphite is provided on the inner and outer surfaces of the fire resistant expanded layer within a range not impairing the fire resistance of the fire resistant expanded layer. However, in consideration of the inner surface smoothness, it is preferable to provide a resin layer made of a resin composition not containing expanded graphite on the inner surface of the refractory expansion layer. Furthermore, if the inner surface coating layer has a multi-row inner surface spiral structure, the drainage performance is also improved, which is preferable.
In the case of the single-layer structure product, the fire-resistant and heat-expandable resin composition for forming the fire-resistant expansion layer is not particularly limited, but the heat-expandable graphite is 1 to 100 parts by weight of the polyvinyl chloride resin. What is contained at a ratio of 10 parts by weight is preferable, more preferably 1 to 8 parts by weight, and even more preferably 2 to 7 parts by weight. That is, if the thermal expansive graphite is less than 1 part by weight, sufficient thermal expansibility may not be obtained at the time of combustion, and the desired fire resistance may not be obtained. If it expands too much, its shape cannot be maintained and the residue falls off, which may reduce the fire resistance.
On the other hand, in the case of a multilayer structure product, the fire-resistant and heat-expandable resin composition for forming the fire-resistant and expandable layer is not particularly limited, but the heat-expandable graphite is 1 to 15 with respect to 100 parts by weight of the polyvinyl chloride resin. What is contained in the ratio of a weight part is preferable, What is contained in the ratio of 1-12 weight part is more preferable, What is contained in the ratio of 2-10 weight part is further more preferable. That is, if the thermally expandable graphite is less than 1 part by weight of the thermally expandable graphite, sufficient thermal expansion cannot be obtained at the time of combustion, and desired fire resistance cannot be obtained. As a result of the thermal expansion, the shape cannot be maintained and the residue may fall off, resulting in a decrease in fire resistance.

In the case of the multilayer structure as described above, the thickness of the coating layer covering the inner surface of the refractory tube is preferably 0.2 to 2.0 mm.
That is, if the thickness of the coating layer covering the inner surface of the fireproof expansion layer is less than 0.2 mm, the inner surface smoothing effect becomes insufficient, and if it exceeds 2.0 mm, the fire resistance may be lowered.

The thermally expandable graphite used in the present invention is a powder of natural scale-like graphite, pyrolytic graphite, quiche graphite or the like, and an inorganic acid such as concentrated sulfuric acid, nitric acid or selenic acid, concentrated nitric acid, perchloric acid, perchlorate, perchlorate. With a strong oxidizer such as manganate, dichromate, hydrogen peroxide, etc., after the acid treatment to insert an inorganic acid between the graphite layers, the layer structure of carbon obtained by adjusting the pH is maintained. It is preferable to use a thermally expandable graphite which is a crystalline compound and adjusted to pH 1.5 to 4.0 and a heat expandable graphite having a 1.3 times expansion temperature of 180 ° C. to 240 ° C.
That is, if the pH of the heat-expandable graphite is less than 1.5, the acidity is too strong to easily cause corrosion of the molding apparatus. If the pH exceeds 4.0, the effect of promoting the carbonization of the polyvinyl chloride resin It may become thin and sufficient fire resistance performance may not be obtained.

The pH adjustment method of the thermally expandable graphite is not particularly limited, but normally, in the state of acid treatment that inserts an inorganic acid between the layers of the raw graphite as described above, the pH is 1 or less. There is a method in which the graphite after acid treatment is washed with water to remove the acid remaining on the surface of the graphite and then dried. That is, in order to increase the pH of the thermally expandable graphite, water washing and drying may be repeated.
On the other hand, if the expansion temperature of the heat-expandable graphite is less than 180 ° C, the heat-expandable graphite may expand during molding, which causes poor appearance of the tube and fire resistance during combustion. When the 1.3 times expansion temperature of the thermally expandable graphite exceeds 240 ° C., there is no fear that the expansion of the thermally expandable graphite will start during molding, After the thermal decomposition (foaming) of the polyvinyl chloride resin progresses and the flexibility of the polyvinyl chloride resin decreases, the thermally expandable graphite expands. There is a risk that it will not be able to withstand the expansion of graphite and will collapse apart.
The 1.3 times expansion temperature is a temperature at which the expansion ratio of the thermally expandable graphite after heating the sample of the thermally expandable graphite for 30 minutes with the inside of the heating furnace becomes a constant temperature is 1.3 or more. means. Further, the expansion ratio can be obtained by dividing the volume of the sample after heating by the volume of the sample before heating.

  Although the particle diameter of the said thermally expansible graphite is not specifically limited, Preferably it is 100-400 micrometers, More preferably, it is 120-350 micrometers. That is, if the particle size becomes too fine, the expansion rate of the refractory resin composition may decrease. On the other hand, if the particle size becomes too large, the structure expands too much due to heating, the shape cannot be maintained, the residue falls off, the fire resistance decreases, and the fire resistant resin composition is used as a piping material. The physical properties, such as tensile strength and flat strength, may decrease, and the mechanical strength necessary for the tube material may not be obtained.

In addition, the fire-resistant and heat-expandable resin composition for forming the fire-resistant expansion layer has a stabilizer, an inorganic filler, a flame retardant, a lubricant, a processing aid, an impact modifier, and the like within a range not impairing the object of the present invention. Additives such as a quality agent, a heat resistance improver, an antioxidant, a light stabilizer, an ultraviolet absorber, a pigment, a plasticizer, and a thermoplastic elastomer may be added.
The stabilizer is not particularly limited, and examples thereof include lead stabilizers, organotin stabilizers, higher fatty acid metal salts, and the like, and these can be used alone or in combination.

Examples of lead stabilizers include lead white, basic lead sulfite, tribasic lead sulfate, dibasic lead phosphite, dibasic lead phthalate, tribasic lead maleate, silica gel coprecipitated silicic acid. Lead, dibasic lead stearate, lead stearate, lead naphthenate are mentioned.
Examples of the organotin stabilizer include mercaptides such as dibutyltin mercapto, dioctyltin mercapto, and dimethyltin mercapto; And carboxylates such as dibutyltin mercaptodibutyltin laurate and dibutyltin laurate polymer.

  Examples of the higher fatty acid metal salt (metal soap) include lithium stearate, magnesium stearate, calcium stearate, calcium laurate, calcium ricinoleate, strontium stearate, barium stearate, barium laurate, barium ricinoleate, and stearic acid. Cadmium, cadmium laurate, cadmium ricinoleate, cadmium naphthenate, cadmium 2-ethylhexoate, zinc stearate, zinc laurate, zinc ricinoleate, zinc 2-ethylhexoate, lead stearate, lead dibasic stearate, naphthene Lead acid is mentioned.

The blending ratio of the stabilizer is not particularly limited, but is preferably 0.3 to 5.0 parts by weight with respect to 100 parts by weight of the polyvinyl chloride resin.
That is, if the blending ratio of the stabilizer is less than 0.3 parts by weight, it is difficult to ensure the thermal stability of the polyvinyl chloride resin at the time of molding, and there is a possibility that carbide is likely to be produced during molding. If the amount exceeds 0.0 parts by weight, the promotion of carbonization of the polyvinyl chloride resin during combustion may be hindered, and sufficient fire resistance may not be obtained.

The inorganic filler is not particularly limited. For example, silica, diatomaceous earth, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, calcium hydroxide, magnesium hydroxide , Aluminum hydroxide, Basic magnesium carbonate, Calcium carbonate, Magnesium carbonate, Zinc carbonate, Barium carbonate, Dawnite, Hydrotalcite, Calcium sulfate, Barium sulfate, Gypsum fiber, Calcium silicate, Talc, Clay, Mica, Montmorillonite, Bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica-based balun, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balun, charcoal powder, various metals Candidates include potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, zinc borate, various magnetic powders, slag fiber, fly ash, dehydrated sludge, etc. Of these, basic inorganic fillers such as calcium carbonate, calcium silicate, calcium hydroxide, calcium oxide, magnesium carbonate, magnesium hydroxide, magnesium oxide, barium carbonate, aluminum hydroxide, zinc oxide, zinc hydroxide and iron oxide Is preferably used.
These may be used alone or in admixture of two or more.

  The blending ratio of the inorganic filler is not particularly limited, but is preferably 0.3 to 50 parts by weight with respect to 100 parts by weight of the polyvinyl chloride resin, and 2 to 5 parts by weight. It is more preferable. That is, if the inorganic filler is less than 0.3 parts by weight, the aggregate function may not be achieved during combustion, and the shape may not be maintained, and the residue may drop, resulting in a decrease in fire resistance. If the amount exceeds 50 parts by weight, the ratio of the polyvinyl chloride resin to the whole composition becomes low, so that the tensile strength may be lowered.

  In particular, when using the heat-expandable graphite whose pH is adjusted to 1.5 to 4.0, the basic inorganic filler is added to 0.3 to 100 parts by weight of the polyvinyl chloride resin. It is preferable to mix | blend in the ratio of 5.0 weight part. That is, when the blending ratio of the basic inorganic filler is less than 0.3 parts by weight with respect to 100 parts by weight of the polyvinyl chloride resin, the thermal stability of the polyvinyl chloride resin at the time of molding cannot be secured, and molding is performed. If the basic compound exceeds 5.0 parts by weight, the promotion of carbonization of the polyvinyl chloride resin during combustion may be hindered, and the fire resistance may not be significantly improved. There is.

  The flame retardant is not particularly limited as long as it is for enhancing flame retardancy during combustion. For example, hydroxides such as aluminum hydroxide and magnesium hydroxide, hydrotalcite, antimony dioxide, and antimony trioxide. Antimony oxides such as antimony pentoxide, molybdenum compounds such as molybdenum trioxide, molybdenum disulfide, ammonium molybdate, bromine compounds such as tetrabromobisphenol A, tetrabromoethane, tetrabromoethane, tetrabromoethane, triphenylphosphine Phosphorus compounds such as phosphate and ammonium polyphosphate, calcium borate, zinc borate and the like can be mentioned, but antimony trioxide is particularly preferable as a combustion suppressing effect of polyvinyl chloride. This is because the antimony compound has a very strong synergistic effect in producing a halogenated antimony compound under high temperature conditions and suppressing the combustion cycle in the presence of a halogen compound.

  By using a flame retardant in combination, the heat insulation effect due to the expansion of the thermally expandable graphite and the combustion delay effect due to the flame retardant exhibit a synergistic effect during combustion, and the fire resistance can be improved more efficiently. The number of added flame retardants is not particularly limited, but it is preferably 1 to 20 parts by weight with respect to 100 parts by weight of the polyvinyl chloride resin. If the flame retardant is less than 1 part by weight, it is difficult to obtain a sufficient synergistic effect, and if the flame retardant is added in excess of 20 parts by weight, the moldability and physical properties may be significantly reduced. is there.

  The heat stabilization aid is not particularly limited, and examples thereof include epoxidized soybean oil, phosphate ester, polyol, hydrotalcite, and zeolite. These may be used alone or in combination of two or more.

Examples of the lubricant include an internal lubricant and an external lubricant.
The internal lubricant is used for the purpose of lowering the flow viscosity of the molten resin during molding and preventing frictional heat generation. The internal lubricant is not particularly limited, and examples thereof include butyl stearate, lauryl alcohol, stearyl alcohol, epoxy soybean oil, glycerin monostearate, stearic acid, and bisamide. These may be used alone or in combination of two or more.
The external lubricant is used for the purpose of increasing the sliding effect between the molten resin and the metal surface during molding. The external lubricant is not particularly limited, and examples thereof include paraffin wax, polyolefin wax, ester wax, and montanic acid wax. These may be used alone or in combination of two or more.

  The processing aid is not particularly limited, and examples thereof include acrylic processing aids such as alkyl acrylate-alkyl methacrylate copolymers having a weight average molecular weight of 100,000 to 2,000,000. The acrylic processing aid is not particularly limited, and examples thereof include n-butyl acrylate-methyl methacrylate copolymer and 2-ethylhexyl acrylate-methyl methacrylate-butyl methacrylate copolymer. These may be used alone or in combination of two or more.

  The impact modifier is not particularly limited, and examples thereof include methyl methacrylate-butadiene-styrene copolymer (MBS), chlorinated polyethylene, and acrylic rubber.

  The heat resistance improver is not particularly limited, and examples thereof include α-methylstyrene-based and N-phenylmaleimide-based resins.

  It does not specifically limit as said antioxidant, For example, a phenolic antioxidant etc. are mentioned.

  The light stabilizer is not particularly limited, and examples thereof include hindered amine light stabilizers.

  The ultraviolet absorber is not particularly limited, and examples thereof include salicylic acid ester-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ultraviolet absorbers.

  The pigment is not particularly limited, and examples thereof include organic pigments such as azo, phthalocyanine, selenium, and dye lakes; oxides, molybdenum chromates, sulfides / selenides, ferrocyanides, and the like. Examples include inorganic pigments.

  In addition, a plasticizer may be added to the polyvinyl chloride resin composition, but since it may reduce the heat resistance and fire resistance of the molded product, it is not preferable to use a large amount. The plasticizer is not particularly limited, and examples thereof include dibutyl phthalate, di-2-ethylhexyl phthalate, and di-2-ethylhexyl adipate.

The thermoplastic elastomer is not particularly limited. For example, acrylonitrile-butadiene copolymer (NBR), ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl acetate-carbon monoxide copolymer (EVACO), Vinyl chloride thermoplastic elastomers such as vinyl chloride-vinyl acetate copolymer and vinyl chloride-vinylidene chloride copolymer, styrene thermoplastic elastomer, olefin thermoplastic elastomer, urethane thermoplastic elastomer, polyester thermoplastic elastomer, Examples thereof include polyamide-based thermoplastic elastomers. These thermoplastic elastomers may be used alone or in combination of two or more.
On the other hand, in the drainage pipe structure according to the present invention, a metal drainage joint having a vertical pipe connection portion provided above and below the main body portion and a side branch pipe connection portion provided on the side surface of the main body portion has a fireproof compartment at the lower end portion. Is installed through the fire protection section so as to protrude downward, and the vertical pipe connection part is formed with the resin lining steel pipe of the present invention connected to the upper and lower vertical pipe connection parts. It is characterized in that a conductive resin tube is connected.
Although it does not specifically limit as said non-refractory resin pipe, For example, chloride, such as a thick-wall vinyl chloride resin pipe (VP), a thin-wall vinyl chloride resin pipe (VU), a recycled vinyl chloride resin three-layer pipe (RF-VP) Vinyl resin based tubes are preferred.

As described above, the resin-lined steel pipe according to the present invention includes at least a fire-resistant expansion layer having a tubular shape made of a fire-resistant and heat-expandable resin composition. When used, it is possible to sufficiently delay the flame and hot air generated on the lower floor from passing through the inside of the joint joint and reaching the side branch pipe connected to the side branch pipe connecting portion.
That is, when a fire occurs and the resin lining tube is struck by a flame, the resin composition constituting the resin lining layer softens and the thermally expandable graphite contained in the fire resistant expansion layer thermally expands, and the resin lining layer The whole expands in the inner diameter direction of the tube and the inner surface of the tube is closed, and a heat insulating effect is exhibited, so that hot air is more effectively delayed in the combustion rate.

Therefore, like the drainage pipe structure of the present invention, it is possible to use a non-fire-resistant inexpensive vinyl chloride resin pipe as the side branch pipe connected to the side branch pipe connecting portion, thereby reducing the construction cost. .
Of course, since the resin-lined steel pipe is used as a standing pipe, it is excellent in sound insulation and workability.

And, as a resin lining layer, a single-layer structure of only a fire-resistant expansion layer composed of a fire-resistant and heat-expandable resin composition containing 1 to 10 parts by weight of thermally expandable graphite with respect to 100 parts by weight of a polyvinyl chloride resin. If the pipe is used, since the polyvinyl chloride resin having self-extinguishing properties is used as the base resin, the combustion speed is effectively delayed and the propagation speed of the flame during combustion can be suppressed. . In addition, since the polyvinyl chloride resin has a property of foaming at the initial stage of combustion, there is an advantage that the thermally expandable graphite is easily expanded.
Further, since the heat-expandable graphite itself is difficult to burn and expands due to heat and exhibits a heat insulation effect, the combustion rate is further effectively delayed.

On the other hand, as a resin lining layer, a fire-resistant expansion layer comprising a fire-resistant and heat-expandable resin composition containing 1 to 15 parts by weight of thermally expandable graphite with respect to 100 parts by weight of a polyvinyl chloride resin, and this fire-resistant expansion If a pipe having a multilayer structure provided with a coating layer made of a polyvinyl chloride resin composition containing no heat-expandable graphite provided so as to cover the inner surface of the layer is used as a base resin, self-extinguishing properties can be obtained. Since the polyvinyl chloride-based resin is used, the combustion speed is effectively delayed, and the flame propagation speed during combustion can be suppressed. In addition, since the polyvinyl chloride resin has a property of foaming at the initial stage of combustion, there is an advantage that the thermally expandable graphite is easily expanded.
Further, since the heat-expandable graphite itself is difficult to burn and expands due to heat and exhibits a heat insulation effect, the combustion rate is further effectively delayed.
Moreover, it has excellent pipe formability, for example, it can be continuously produced with high dimensional accuracy by injection molding or extrusion molding, etc., and the inner surface of the pipe can be made into a smooth state. It can be excellent in drainage performance.

Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof.
FIG. 1 shows one embodiment of a resin-lined steel pipe according to the present invention.

As shown in FIG. 1, in the resin-lined steel pipe 1, the inner surface of the steel pipe 11 is covered with a resin-lining layer 12.
The resin lining layer 12 has a two-layer structure of a fireproof expansion layer 12a and an inner surface coating layer 12b.

The fire-resistant expansion layer 12a has 1 to 15 parts by weight of thermally expandable graphite whose pH is adjusted to 1.5 to 4.0 with respect to 100 parts by weight of the polyvinyl chloride resin, and 0.3 to 5 stabilizers. It is formed with a fireproof and thermally expandable resin composition blended at a ratio of 0.0 part by weight.
The inner surface coating layer 12b is formed of a polyvinyl chloride resin composition not containing thermally expandable graphite.

  And although not shown in figure, this resin-lined steel pipe 1 was first molded by coextrusion molding with an extrusion molding machine generally used for a resin pipe provided with an inner surface coating layer 12b on the inner surface of the fireproof expansion layer 12a. After that, a steel pipe having an inner diameter slightly larger than the outer diameter of the resin pipe is externally fitted on the outer surface of the resin pipe in the same manner as in a known method for manufacturing a resin lining pipe, and the inner surface of the steel pipe is an adhesive layer (for example, hot It can be obtained by drawing a steel pipe so as to be in close contact with the outer surface of the resin pipe via a melt adhesive).

This resin-lined steel pipe 1 is as described above, and a drainage pipe structure A as shown in FIG. 2 can be constructed.
That is, as shown in FIG. 2, the drainage pipe structure A includes a drainage collective joint 2, the resin-lined steel pipe 1 serving as a vertical pipe, a vinyl chloride resin pipe containing no thermally expandable graphite serving as a lateral branch pipe, and the like. It consists of a non-fire resistant resin tube 3.

The drainage collective joint 2 is formed of cast iron, and includes a main body portion 21, an upper vertical pipe connection portion 22, a lower vertical pipe connection portion 23, and three horizontal branch pipe connection portions 24.
The main body portion 21 has a large-diameter portion 21a at the upper portion, and a side branch pipe connecting portion 24 projects from the side surface of the large-diameter portion 21a, and the upper vertical pipe connecting portion 22 extends from the ceiling portion of the large-diameter portion 21a. Projected.

  The lower portion of the large diameter portion 21a of the main body portion 21 is a reduced diameter portion 21b having a diameter that gradually decreases toward the lower end until the inner diameter is substantially the same as the inner diameter of the resin-lined steel pipe 1, and has a straight pipe portion at the lower end. A swirl vane 21c is provided on the inner surface of the reduced diameter portion 21b. The lower vertical pipe connection part 23 is connected to the lower end of the reduced diameter part 21b.

  And the construction method is, for example, installing the drainage collective joint 2 so that the lower vertical pipe connection portion 23 is below the concrete floor slab 4 which is a fire prevention section, and tightening the lower vertical pipe connection portion 23 After the upper end of the resin lining steel pipe 1 on the lower floor is inserted into the lower vertical pipe connecting portion 23 with the tightening of 25 tightened, the bolt 26 of the tightening ring 25 is tightened as shown in FIG. The upper end portion of the lining steel pipe 1 is firmly fixed to the drainage collective joint 2 by the packing 6.

  Note that. As shown in FIG. 4, the packing 6 of the lower vertical pipe connection portion 23 is not only a grip by rubber elasticity but also a resin-lined steel pipe 1 such as a rubber main body 61 provided with a metal locking ring 62. The rubber main body 61 is pressed against the wall surface of the resin-lined steel pipe 1 by the tightening by the tightening ring 25, and simultaneously acts to bite into the wall surface of the resin-lined steel pipe 1 so as to prevent the resin-lined steel pipe 1 from dropping downward. It is preferable to use one provided with a simple locking mechanism. That is, as shown in FIG. 4, the packing 6 has a ring-shaped rubber main body 61 and a substantially C-shape with a part cut away as shown in FIG. As shown in FIG. 4 (b), as shown in FIG. 4 (b), it is provided with a taper away from the end surface of the rubber main body 61 from the inner diameter side toward the outer diameter side, and has a C-shaped open end and an intermediate Locking protrusions 61a protruding from the end face of the rubber main body 61 are fitted into holes 62a provided at three positions. The packing 6 is capable of watertightly fixing the resin-lined steel pipe 1 to the lower vertical pipe connection portion 23 by the rubber main body 61 by tightening with the tightening ring 25, and prevents the resin-lined steel pipe 1 from being detached by the locking ring 62. Can be planned.

Next, the mortar 5 is filled and solidified in the gap between the through-hole 41 and the drainage collective joint 2, and then the lower end portion of the resin lining steel pipe 1 on the upper floor is connected to the upper vertical pipe connection portion 22 to connect the side branch pipe The non-refractory resin tube 3 is connected to the portion 24.
These operations are repeated one after another toward the upper floor.

  Since the drain pipe structure A uses the resin-lined steel pipe 1 provided with the resin lining layer 12 having the fire-resistant expansion layer 12a as described above, a fire occurs on the lower floor and the resin-lined steel pipe is used. When 1 is exposed to a flame, the resin lining layer 12 expands toward the inside of the tube by the action of the thermally expandable graphite in the refractory expansion layer 12a, and the inside of the tube is closed. Therefore, it is difficult for hot air due to fire to flow into the drainage collective joint 2 on the upper floor, and the non-refractory resin pipe can be used as the side branch pipe as described above, and the construction cost can be reduced.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the collective joint is configured to fix the resin lining by tightening the tightening ring, but the upper vertical pipe connection portion has a receiving structure with a rubber ring. It doesn't matter.

  Hereinafter, specific examples of the present invention will be described.

(Examples 1 to 31 and Comparative Example 1)
Pipes having an outer diameter of 114 mm, a thickness of 6.6 mm, and a nominal diameter of 100 A having the composition shown in Tables 1 to 5 were obtained by extrusion using a generally used extruder.
In addition, in the Example shown in Table 1-Table 5, the following were used as a compounding material of the resin composition which comprises each layer.
Vinyl chloride resin: Tokuyama Sekisui Industry Co., Ltd., trade name TS1000R
Lead stearate ・ ・ ・ Mizusawa Chemical Co., Ltd., trade name Stabinex NC18
Octyl tin mercapto ・ ・ ・ Sansha Co., Ltd., ONE-100F
Ca / Zn composite stabilizer ・ ・ ・ Made by Kago Chemical Co., Ltd., trade name NWP-6000
Lubricant ・ ・ ・ Mitsui Chemicals, trade name High Wax 4202E
Calcium carbonate (inorganic filler) ・ ・ ・ Shiraishi Calcium Co., Ltd.
Magnesium hydroxide (inorganic filler) ・ ・ ・ Kyowa Chemical Industry Co., Ltd., trade name KISUMA5A
Hydrotalcite: Kyowa Chemical Industry Co., Ltd., trade name: DHT-4A
Epoxidized soybean oil: ADEKA, brand name Adeka Sizer O130P
Thermally expansive graphite: Tosoh Corporation, product number GREP-EG

(Example 32 to Example 80)
A pipe having an outer diameter of 114 mm, a thickness of 6.6 mm, and a nominal diameter of 100 A, which has a coating layer on at least one of the inner and outer surfaces of the fireproof expansion layer having the composition shown in Tables 6 to 13 below, is generally used. Obtained by coextrusion with an extrusion machine.
In addition, in the Example shown to Tables 6-13, the following were used as a compounding material of the resin composition which comprises each layer.
Vinyl chloride resin: Taiyo PVC Co., Ltd., trade name: TH1000
Lead-based stabilizer ・ ・ ・ Product name SL-1000
Lubricant ・ ・ ・ Mitsui Chemicals, trade name High Wax 4202E
Calcium carbonate (inorganic filler) ・ ・ ・ Shiraishi Calcium Co., Ltd.
Magnesium hydroxide (inorganic filler) ・ ・ ・ Kyowa Chemical Industry Co., Ltd., trade name KISUMA5A
Hydrotalcite: Kyowa Chemical Industry Co., Ltd., trade name: DHT-4A
Epoxidized soybean oil: ADEKA, brand name Adeka Sizer O130P
Thermally expansive graphite: Tosoh Corporation, trade name GREP-EG

  About the pipe produced in the said Examples 1-80 and the comparative example 1, the fire resistance evaluation and physical-property evaluation shown below were performed, respectively, and the result was combined with Table 1-Table 8, and was shown. In the case of a multilayer structure, the thickness and thickness ratio of each layer are also shown.

(Fire resistance evaluation)
A fire resistance test (according to ISO 834-1, an evaluation method for the fire resistance performance test of the revised Building Standard Law, which was enforced on June 1, 2000) was performed by the fire resistance test furnace X shown in FIG.
As the flooring Y, a PC (precast concrete) panel having a thickness of 100 mm was used. The test pipe P was passed through the partition penetration portion R provided in the flooring Y, exposed 300 mm in the heating chamber Z, and exposed 800 mm outside the flooring Y.
Burners V and V are installed on the side wall of the heating chamber Z. Further, a thermocouple Q for temperature measurement is installed in the vicinity of the tip of the test piping material P.
After the heating was started, the time (smoke generation time) until smoke was emitted from the gap between the partition through portion R and the test piping material P was measured. The smoke generation time was examined according to the criteria of the 8th division of the Fire Service Act.

(Evaluation of the physical properties)
Dumbbell test pieces are arbitrarily cut out from the pipes obtained in the above (Example 1) to (Example 80) and (Comparative Example 1), and the obtained test pieces are subjected to a tensile test (evaluation temperature 23) in accordance with JISK7113. ° C). In addition, in order to determine whether or not the practical performance as a tube is satisfied, the one having a tensile strength of 45 (MPa) or more at 23 ° C. is ◎ (excellent), the one having 30 (MPa) or more is ○ (pass), Those less than 30 (MPa) were evaluated as x (failed).

It is sectional drawing showing one embodiment of the resin-lined steel pipe concerning this invention. It is sectional drawing showing one embodiment of the drain piping structure of this invention using the resin lining steel pipe of FIG. It is an expanded sectional view of the lower vertical pipe connection part of the drainage collective joint of the drainage piping structure of FIG. It is a figure explaining the suitable example of the packing used for the lower vertical pipe connection part of a drainage collective joint, Comprising: The figure (a) is a top view, The figure (b) is the II line | wire of the figure (a). It is sectional drawing. It is a figure explaining the method of the fire resistance test of the pipe obtained in the Example.

Explanation of symbols

A Drainage pipe structure 1 Resin lining steel pipe 11 Steel pipe 12 Resin lining layer 12a Fireproof expansion layer 12b Inner surface coating layer 2 Drainage collective joint 21 Main body part 22 Upper vertical pipe connection part 23 Lower vertical pipe connection part 24 Side branch pipe connection part 3 Non-fireproof Resin Tube 4 Floor Slab (Fire Protection Section)

Claims (4)

In resin-lined steel pipes with a resin-lining layer on the inner surface,
The resin-lined steel pipe, wherein the resin-lined layer includes at least a fire-resistant expansion layer having a tubular shape made of a fire-resistant and heat-expandable resin composition.   The resin lining layer has a single-layer structure of a fire-resistant expansion layer composed of a fire-resistant and heat-expandable resin composition containing 1 to 10 parts by weight of thermally expandable graphite with respect to 100 parts by weight of the polyvinyl chloride resin. Item 4. The resin-lined steel pipe according to Item 1.   The resin lining layer is composed of a fire-resistant and thermally-expandable resin composition comprising 1 to 15 parts by weight of thermally expandable graphite with respect to 100 parts by weight of the polyvinyl chloride resin, and at least a fire-resistant and expanded layer. 2. The resin-lined steel pipe according to claim 1, wherein the resin-lined steel pipe has a multilayer structure including a coating layer made of a resin composition containing no thermally expandable graphite on the inner surface side.   A metal drainage joint with a vertical pipe connection provided on the top and bottom of the main body and a side branch pipe connection on the side of the main body penetrates the fire protection compartment so that the lower end protrudes below the fire protection compartment In addition, a vertical pipe line in which the resin-lined steel pipe according to any one of claims 1 to 3 is connected to the upper and lower vertical pipe connection parts is formed, and the horizontal branch pipe connection part has non-fire resistance. A drainage pipe structure characterized in that a resin pipe is connected.

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