JPH056293U - Flame retardant insulation tube - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a heat insulating pipe that does not spread the heat insulating layer or melt and drip, and is less likely to cause a decrease in heat insulating efficiency due to thinning. [Structure] A tubular body 1 in which a heat insulating layer 1b of a silicone foam is formed on the outer peripheral surface of the tubular body 1a, and the tubular body 1 is arranged on the outer periphery of the tubular body 1 and a polyolefin resin is mixed with an inorganic filler and red phosphorus. And a corrugated tube 2 of a resin composition. [Effect] Since the heat insulating layer is a silicone-based foam, there is no spread of fire or dripping. The outermost corrugated pipe has flame retardancy and excellent mechanical strength, and further suppresses the thinning of the heat insulating layer, thus preventing a decrease in heat insulating efficiency.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention relates to a flame-retardant coated heat-insulating pipe, and more specifically, it has excellent flame-retardant and heat-insulating properties. Not only that, it also has good compression resistance and impact resistance, and excellent pipe support. , Refrigerant for piping and air conditioner for water / hot water required for building construction The present invention relates to a flame-retardant coated heat insulating pipe suitable as a pipe.

[0002]

[Prior art]

  Pipes for water and hot water supply and refrigerant pipes for air conditioners are generally similar to copper pipes. Heat insulation by covering the outer peripheral surface of various metal pipes and various resin pipes with plastic foam A layer is formed on the surface of this heat insulating layer, for example polyethylene, polypropylene, Extrusion coating of polyolefin resins such as ethylene-vinyl acetate copolymer Or protected by covering with polyvinyl chloride film or polyethylene film A layered structure is generally used.

[0003]   On the other hand, at the construction site, on the other hand, the outer peripheral surface of the above-mentioned tubular body is usually covered with glass wool or Coated with an inorganic heat insulating material such as wool, calcium silicate, and glass Finished into a heat-insulating tube by using loose tape to prevent it from falling apart.   Of these two types of heat insulation pipes, the former one is disconnected again at the pipe construction site. It has excellent workability because it does not require heat treatment. But heat insulation layer etc. Since most of them are made of polyolefin resin, they have a difficulty in flame retardancy. For example, in the event of a fire, it is said that the heat insulating layer spreads and is easily destroyed by fire. I have a problem.

[0004]   The latter, on the other hand, does not have the problem of burnout of insulation, but is narrow There is a problem in workability in the place, and the finish state varies depending on the worker. May damage the aesthetics.   In order to solve the problem in the conventional heat insulating pipe, the present inventors We have developed a flame-retardant coated heat-insulating pipe with a structure using silicone-based foam as a material, and have already I applied for this as Jitsukaihei 2-30600.

[0005]   This adiabatic tube has excellent flame retardance and can be manufactured integrally in a factory. Therefore, the work of covering the heat insulating material at the construction site can be eliminated.

[0006]

[Problems to be solved by the device]

  However, in the case of the above-mentioned heat insulation pipe, the silicone foam, which is a heat insulation material, is difficult. It is excellent in flammability, but its softness causes the following problems.   For example, when piping this heat insulation pipe in the horizontal direction, support the heat insulation pipe at a predetermined interval. Will be required. Therefore, as shown in the sectional view of FIG. An adiabatic heat insulating layer 1a and a silicone foam heat insulating layer 1b with an outer diameter of Do When the tube 1 is supported by the support tool 4 as shown in the sectional view of FIG. Due to the weight of the heat insulating pipe 1 and the weight of the fluid flowing in the pipe 1a, When a compressive force is applied downward, it is supported by the support 4 of the soft heat insulating layer 1b.                                                                    The outer diameter of the entire heat insulating pipe 1 becomes D due to the thinned portion, and the whole is slightly It has a flat shape. The (Do-D) / D × 100 at this time is called the normal flatness rate (%). ing. Thus, when the heat insulating layer 1b is thinned, the heat insulating efficiency of the heat insulating layer 1b is reduced. Then, that part is likely to be condensed.

[0007]   In order to reduce the thickness reduction of the heat insulation layer 1b, the support interval of the heat insulation pipe 1 should be shortened. Reduce the compressive force to the heat insulation layer 1b or increase the heat insulation layer support length of the support tool 4. However, such a procedure would add to the work of plumbing. Make it messy.   Further, in the case of the heat insulating tube described above, the heat insulating layer 1b of the silicone-based foam is soft. Therefore, the surface of the heat insulating layer 1b may be damaged during construction, and the site construction property Is not always suitable.

[0008]   The present invention relates to the above heat insulating tube in which the heat insulating layer 1b is made of silicone foam. It is said that it solves the above problems and is excellent in flame retardancy. There is little thinning of the heat insulation layer caused by holding, so there is no decrease in heat insulation efficiency, and To provide flame-retardant insulation pipes that can be installed without damaging the insulation layer To aim.

[0009]

[Means for Solving the Problems]

  In order to achieve the above-mentioned object, in the present invention, the outer surface of the pipe body is made of silicone. A tubular body on which a heat insulating layer of foam is formed, and the tubular body is arranged on the outer periphery of the tubular body, Corrugation of resin composition in which polyolefin resin is mixed with inorganic filler and red phosphorus There is provided a flame-retardant coated heat-insulating pipe, which is characterized in that it comprises an insulating pipe.

[0010]   Hereinafter, the heat insulating pipe of the present invention will be described with reference to the accompanying drawings. Figure 1 shows the heat insulation of the present invention FIG. 2 is a partially cutaway side view showing a pipe, and FIG. 2 is a sectional view taken along line II-II in FIG. 1.   In the figure, the outer circumference of the tubular body 1a through which water, hot water, gas, liquefied gas, etc. flow. A heat insulating layer 1b is integrally formed on the surface by closely coating with a silicone foam described later. The heat insulating tubular body 1 is formed by itself.

[0011]   The tube body 1a is not particularly limited, and may be, for example, copper, copper alloy, iron, stainless steel. Steel tube made of stainless steel, aluminum, etc .; from ceramics, glass, FRP, etc. Comprising non-metallic tubes; or polyolefins such as polyethylene, polypropylene Alternatively, a cross-linked product thereof or a resin pipe made of polyamide or the like can be mentioned. Wear.

[0012]   The silicone-based foam of the heat insulating layer 1b that covers the tubular body 1a is chemically stable. Si-O bond as the main chain, for example, liquid silicone rubber as the main raw material Foam molding method or foam molding using millable silicone rubber as the main raw material Can be obtained by law.   A method for forming a heat insulating layer 1b by coating the tubular body 1a with this silicone foam For example, a silicone-based foam is molded into a tubular body in advance, and the hollow body is filled with a tubular body. 1a, or press the foamed silicone rubber directly on the outer peripheral surface of the tubular body 1a. A coating method or the like can be adopted.

[0013]   On the outer periphery of the tubular body 1, a corrugated tube preformed using a resin composition described later. 2 is externally fitted. Therefore, the inner diameter of the corrugated tube 2 is larger than the outer diameter of the tubular body 1. The air layer 3 has a diameter and is formed between the two at desired intervals.   The resin composition forming the corrugated tube 2 contains the polyolefin resin as the main component. It is prepared by using a base polymer and adding an inorganic filler and red phosphorus to the base polymer.

[0014]   Examples of the polyolefin resin include polyethylene, polypropylene and ethyl resin. Ren-α olefin copolymer, ethylene-propylene copolymer, ethylene-acetic acid Vinyl copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate An example is a vinyl chloride copolymer. These are used individually Alternatively, two or more kinds may be appropriately blended and used.

[0015]   These resins are the main materials of the corrugated pipe 2, and contain the inorganic filler described later. However, good mechanical properties such as tensile strength and elongation of the corrugated pipe are ensured, Workability can also be secured. Especially ethylene-ethyl acrylate copolymer Polymer and ethylene-vinyl acetate copolymer have less deterioration of elongation property and extrudability. Is also preferable in that it is also good.

[0016]   The inorganic filler is not particularly limited. Hydrated metal oxides such as minium, magnesium hydroxide and basic magnesium carbonate Materials; Metal oxides such as alumina and titania; Calcium carbonate, magnesium carbonate Carbonates and bicarbonates such as sodium, sodium bicarbonate; zinc borate, borax, e Borates such as barium oxalate; like calcium phosphate, potassium metaphosphate Phosphates; silicates and silicates such as talc and clay; sulfur such as gypsum Acid salts and sulfites; residual waste such as red mud;

[0017]   These may be used alone, or may be used by appropriately mixing two or more kinds. Good. The above filler is used in the form of powder, and the particle size in that case is Because it is easy to disperse uniformly in the polyolefin resin, which is a base polymer, The average particle size is preferably 0.01 to 30 μm.   Of these, hydrated metal oxides are retained by themselves when the resin composition burns. To release heat of crystallization and suppress heat generation, and melt droplets of the resin composition even when in contact with a flame It is effective because it exerts the function of preventing bottom and spread of fire.

[0018]   This inorganic filler is 50 to 500 parts by weight per 100 parts by weight of the polyolefin resin. It is preferable to add a part by weight. If the amount is less than 50 parts by weight, the If the above effects are not remarkably exhibited and the amount exceeds 500 parts by weight, the resin composition Physical properties such as poor extrudability and heat insulation of the corrugated tube formed Will be significantly reduced. A particularly preferable blending amount is 100% polyolefin resin. It is 80 to 200 parts by weight with respect to parts by weight.

[0019]   Red phosphorus functions to prevent melting and dropping of the resin composition during combustion. That The compounding amount is preferably 1 to 5 parts by weight with respect to 100 parts by weight of the base polymer. Good If the blending amount is less than 1 part by weight, the effect of preventing melt dripping is not sufficiently exhibited, On the other hand, if the amount exceeds 5 parts by weight, the effect of preventing melt dripping will decrease. It A preferred blending amount is 2 to 4 parts by weight with respect to 100 parts by weight of the base polymer. It

[0020]   Furthermore, commonly used flame retardants, flame retardant aids, antistatic agents, colorants, lubricants, A corrugated pipe may be molded from the resin composition by adding an appropriate amount of a processing aid or the like.

[0021]

【Example】

  Examples 1, 2 and Comparative Example   As shown in Fig. 1, the outer diameter of the copper tube 1a having an outer diameter of 15.88 mm and a wall thickness of 1.02 mm is A tubular body 1 was manufactured by extrusion-coating a heat insulating layer 1b having a thickness of 10 mm with foamed silicone rubber. .

[0022]   On the other hand, 100 parts by weight of ethylene-ethyl acrylate copolymer, aluminum hydroxide 100 parts by weight of um and 2 parts by weight of red phosphorus were kneaded, and the resin composition obtained had an inner diameter of 38 mm. A corrugated tube 2 having an outer diameter of 44 mm and a pitch of 5 mm was molded. This corrugated tube has the above tubular body 1 was inserted into the heat insulating tube of the present invention (Example 1).   The resin composition of the corrugated tube contains 100 parts by weight of ethylene-vinyl acetate copolymer, hydroxy acid. Example except 150 parts by weight of aluminum chloride and 4 parts by weight of red phosphorus A heat insulating tube was manufactured in the same manner as in Example 1 (Example 2).

[0023]   With respect to these heat insulation pipes, various characteristics were measured with the following specifications. The results are shown in Table 1. Indicated. For comparison, the characteristics of the tubular body itself that is not incorporated in the corrugated pipe are measured. The results are also shown in Table 1.   Flame retardance: An evaluation test was conducted according to JIS C3521. 20 minutes of gas The flame height and the amount of smoke generated during combustion were observed, and the extinguishing condition and interruption after the gas burner combustion was stopped. Observe the state of the heat layer.

[0024]   Thermal insulation: Inside a copper pipe 1a in a room atmosphere with a temperature of 35 ° C and a relative humidity of 80% R-22 Freon gas was sealed in the water, and a water flow test was conducted at a refrigerant temperature of -5 ° C. Observe the condensation on the surface of.   Compression resistance: left for 24 hours with a static compression load of 5 kg applied to the side of the heat insulating tube The thinning of the heat insulation layer was observed when unloading, and the flatness was calculated.

[0025]   Pipe supportability: At room temperature of 20 ° C, R-22 Freon gas is sealed in the copper pipe 1a. In a standing condition (total weight is about 1.6 Kg), with a support interval of 1.5 m, with supports of various lengths Supported, and at that time, the length of the support tool was measured when the thickness reduction of the heat insulating layer 1b did not occur. . The shorter the length of this support, the less likely the insulation tube will be thinned. Represent.

[0026]   Impact resistance: Drop a cylinder with a weight of 1.0 kg from the height of 0.5 m on the side of the heat insulation pipe. Therefore, the flat state of the copper tube 1a at that time was measured, and the flatness rate was calculated. This value is small It shows that it has excellent impact resistance.

[0027]

[Table 1]

[0028]

[Effect of device]

  As is clear from the above description, in the flame-retardant coated heat insulating pipe of the present invention, the heat insulating layer is Since it is made of silicone foam, there are no inconveniences such as fire spread of the heat insulation layer and melting and dropping. It does not occur and a high degree of flame retardancy is secured.   The outermost corrugated tube effectively prevents thinning of the soft silicone foam. Even if the heat insulating pipe is supported by a support tool, a decrease in heat insulating efficiency of that portion is prevented. Shi Therefore, it is possible to increase the support interval of the heat insulation pipe, which reduces the construction cost. Is possible.

[0029]   In addition, both the heat insulation layer and the corrugated pipe generate extremely little smoke during combustion and are harmful. No gas is generated.   In addition, the heat insulation pipe of the present invention has both a heat insulation layer and a corrugated pipe, Since it can be formed on the outer peripheral surface, there is no disconnection at the construction site as in the conventional case. The work of covering the heat layer is unnecessary, and the construction cost can be greatly reduced. .

[0030]   Also, if the corrugated pipe is partially damaged during pipe construction, the heat insulation layer is exposed in a high humidity environment. However, since the heat insulation layer of the silicone-based foam does not have hygroscopicity, The thermal conductivity remains low and a high degree of thermal insulation is ensured.   Since the outermost layer of the heat insulating pipe of the present invention is a corrugated pipe, It is possible to prevent the occurrence of wrinkles in the bending part when bending is performed in the field. This is preferable because it is possible to obtain a piping state with a beautiful appearance.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing a heat insulating tube of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a cross-sectional view of a conventional heat insulating tube in which a heat insulating layer is a silicone-based foam.

FIG. 4 is a cross-sectional view showing a state in which the heat insulating pipe of FIG. 3 has been thinned.

[Explanation of symbols]

1 tubular body 1a tube 1b Insulating layer of silicone foam 2 corrugated tube 3 air layer 4 Supports

Claims (2)

[Scope of utility model registration request] 1. A tubular body in which a heat insulating layer of a silicone foam is formed on the outer peripheral surface of the tubular body, and a resin disposed on the outer periphery of the tubular body and containing a polyolefin resin mixed with an inorganic filler and red phosphorus. A flame-retardant coated heat-insulating pipe comprising a corrugated pipe of the composition. 2. The resin composition comprises 100 parts by weight of a base polymer containing ethylene-ethyl acrylate copolymer and / or ethylene-vinyl acetate copolymer as main components, 50 to 500 parts by weight of inorganic filler, and red. Phosphorus 1
The flame-retardant coated heat-insulating pipe according to claim 1, which comprises -5 parts by weight.