JPH0718211B2 - Externally exposed flame-retardant heat-insulating waterproof rubber sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flame-retardant heat-insulating waterproof rubber sheet exposed to the outside world.

[Prior Art] The waterproof rubber sheet is expanding its fields of use year by year due to its uniform sheet thickness, excellent water impermeability, and good adaptability to the underlying movement. One of the waterproof rubber sheets is roof waterproofing work.

On the other hand, in recent years, there are many examples of roof waterproofing work and heat insulating work being performed at the same time.

In the heat-insulating waterproof roof structure in which such waterproofing work and heat-insulating work are performed at the same time, a heat-insulating sheet is installed on the roof, and a waterproof rubber sheet is adhered on it.

In this case, as the heat insulating sheet, glass fiber, asbestos fiber, inorganic fiber such as rock wool, heat resistant fiber such as aromatic polyamide fiber, expanded polyethylene sheet, expanded polypropylene sheet, expanded polyurethane sheet, expanded plastic sheet such as expanded polystyrene sheet, etc. is there.

Although inorganic fibers and heat-resistant fibers have excellent flame retardancy, they have the drawbacks of poor workability, large weight, and high price.
On the other hand, the foamed plastic sheet has excellent workability,
It is light in weight and very inexpensive. However, the disadvantage of the foamed plastic sheet is that it has higher flammability than inorganic fibers or heat-resistant fibers.

For this reason, a foamed plastic sheet is applied to the roof, and an exposed external heat-insulated waterproof roof structure with a waterproof rubber sheet is spread over the exposed external heat-insulated waterproof roof structure when the foamed plastic sheet is ignited. There is.

Heretofore, the following method has been used as a measure against flame retardance of the exposed outside heat-insulating waterproof roof structure.

(1) A non-combustible concrete is cast on the surface of the waterproof rubber sheet exposed to the outside to form a sealed type.

(2) Paint flame-retardant paint on the surface of the waterproof rubber sheet exposed to the outside.

(3) The foamed plastic sheet is made flame-retardant.

However, in the method of (1), the weight of non-combustible concrete is large, which significantly impairs the lightness, which is the feature of the outside exposed type heat-insulating waterproof roof structure of foamed plastic sheet to waterproof rubber sheet construction, and the construction period depends on the concrete placement process. Becomes longer and further increases the cost.

Further, the method (2) requires thick coating in order to exhibit flame retardancy, resulting in a decrease in construction efficiency and an increase in cost, and further, there is a drawback that weather resistance is poor.

In the method (3), a highly flammable foamed plastic sheet is made flame-retardant by blending a large amount of a flame retardant. As a result, flexibility and mechanical strength of the foamed plastic sheet are remarkably deteriorated, and cost is increased. There is a drawback that the low cost feature is lost.

[Problems to be Solved by the Invention] An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide an externally exposed flame-retardant heat-insulating waterproof sheet that exhibits an excellent fire spread prevention effect. .

[Means for Solving the Problems] The gist of the present invention is to provide a flame-retardant waterproof rubber sheet having an oxygen index of 25 or more laminated and integrated on a foamed plastic sheet. It is in a heat-insulating tarpaulin.

That is, even if a flammable foamed plastic sheet is used as the heat insulating layer in the present invention, surprisingly, the flame retardant waterproof rubber sheet having an oxygen index of 25 or more has excellent flame retardancy obtained by laminating and integrating it on the upper layer. It has been found to exert the

In the present invention, examples of the foamed plastic sheet include a foamed polyethylene sheet, a foamed polypropylene sheet, a foamed polyurethane sheet, and a foamed polystyrene sheet.

As the base rubber of the flame-retardant waterproof rubber sheet in the present invention, ethylene / propylene / diene rubber, a blend rubber of ethylene / propylene / diene rubber to butyl rubber,
Examples include chlorosulfonated polyethylene rubber and chlorinated polyethylene rubber. An appropriate amount of a vulcanizing agent, a vulcanization accelerator, a lubricant, a filler, an antiaging agent, a flame retardant and the like are added to these base rubbers.

The flame retardant is preferably one that generates a flame-retardant gas or flame-retardant fumes at a high temperature immediately before ignition, such as antimony trioxide, antimony trioxide-phosphorus plasticizer mixture, antimony silico oxide, modified meta. Barium borate,
Phosphate, phosphorus compound, phosphorus / chlorine compound, chlorinated paraffin, chlorinated polyphenyl, perchlorpentamicrodecane, tetrabromoethane, tetrabromobutane, 1,2-
Dibromo-3-chloropropane, aluminum hydroxide,
There are magnesium hydroxide and the like. These can be used alone or in appropriate combination of two or more.

These compounding agents are kneaded into a base rubber with a Banbury mixer or the like to obtain an unvulcanized rubber compound, and the obtained unvulcanized rubber compound is formed into a sheet by a calender roll, and after that, in a high temperature and high pressure vulcanizing apparatus. It is vulcanized. In this case, the degree of vulcanization is not particularly limited, but in order to exert sufficient weather resistance, mechanical properties, and fire spread inhibition, the gel fraction after dipping the vulcanized rubber sheet in 120 ° C xylene for 2 hours It is preferably 65% or more.

[Function] The external exposure type flame-retardant heat-insulating tarpaulin of the present invention is formed by laminating and integrating a flame-retardant waterproof rubber sheet having an oxygen index of 25 or more on a foamed plastic sheet, thereby exposing the outside of the waterproof rubber sheet to the outside. Effectively prevent the spread of fire. Here, the oxygen index is one index that represents the flammability of the material, and when the oxygen index is 25 or more, not only the flame retardancy increases, but also an excellent flame spread prevention effect is exerted on the foamed plastic sheet. . For this oxygen index,
For example, in the case of ethylene / propylene rubber, it is usually less than 25, but it becomes 25 or more by adding various additives.
When a specific flame-retardant agent that generates flame-retardant gas or flame-retardant fumes is used as this additive, when the foamed plastic sheet side installed inside the building is ignited, it is heated by the ignition of the foamed plastic sheet. Flame-retardant gas and flame-retardant fumes are generated from the flame-retardant waterproof rubber sheet, and the flame-retardant gases and flame-retardant fumes effectively prevent the spread of the foamed plastic sheet. Moreover, when the flame-retardant waterproof rubber sheet is a cross-linked vulcanized rubber, it does not melt and open due to combustion heat unlike plastics, so that spread of fire can be effectively suppressed.

[Examples] Next, examples of the external exposure type flame-retardant heat-insulating waterproof sheet of the present invention will be described with reference to the drawings.

Example 1 First, an unvulcanized rubber compound was obtained by kneading ethylene / propylene / diene rubber with an appropriate amount of a vulcanizing agent, a vulcanization accelerator, a lubricant, a filler, an antioxidant and a flame retardant with a Banbury mixer or the like. The unvulcanized rubber compound obtained was made into a sheet with a thickness of 1 mm by a calender roll, and then the sheet was vulcanized by a continuous vulcanizer at high temperature and pressure,
A black vulcanized ethylene / propylene / diene rubber sheet with an oxygen index of 25 measured according to JIS-K-7201.
Carbon black was used as the filler, and antimony trioxide, modified barium metaborate, and chlorinated paraffin were used as flame retardants in appropriate amounts.

Next, while continuously heating the resulting black vulcanized ethylene / propylene / diene rubber sheet to 120 ° C at which the foamed plastic sheet softens, a pressure roll consisting of a heat roll at 120 ° C and a cooling roll at room temperature was used. At the same time as it is sent to the heat roll side, a foamed polyethylene sheet with a thickness of 4 mm is continuously sent to the cooling roll side, and pressure is applied at the interface,
By heat fusion, an externally exposed flame-retardant heat-insulating waterproof rubber sheet was obtained.

FIG. 1 is a cross-sectional view of the thus exposed outside flame-retardant heat-insulating waterproof rubber sheet 20 of the present invention. In FIG. 1, 1 is a foamed polyethylene sheet and 22 is a black vulcanized ethylene / propylene / diene rubber sheet having an oxygen index of 25.

Example 2 An externally exposed flame-retardant heat-insulating waterproof rubber sheet was obtained in the same manner as in Example 1 except that a black vulcanized ethylene / propylene / diene rubber sheet having an oxygen index of 28 was used.

Example 3 An externally exposed flame-retardant heat-insulating waterproof rubber sheet was obtained in the same manner as in Example 1 except that a black vulcanized ethylene / propylene / diene rubber sheet having an oxygen index of 34 was used.

Example 4 An appropriate amount of a vulcanizing agent, a vulcanization accelerator, a lubricant, a filler, an antioxidant, a flame retardant, and a yellow pigment were kneaded with a chlorosulfonated polyethylene rubber with a Banbury mixer or the like to obtain an unvulcanized rubber compound. The obtained unvulcanized rubber compound was made into a sheet having a thickness of 1 mm with a calender roll, and then the sheet was vulcanized with a continuous vulcanizer at high temperature and high pressure, and measured according to JIS-K-7201. A yellow vulcanized chlorosulfonated polyethylene rubber sheet with an oxygen index of 36 is used. As the filler, calcium carbonate and clay were used in combination. As flame retardants, antimony trioxide, chlorinated paraffin, and aluminum hydroxide were mixed in appropriate amounts.

Next, while continuously sending out the obtained yellow vulcanized chlorosulfonated polyethylene rubber sheet having an oxygen index of 36,
In the same manner as in Example 1, a foamed polyethylene sheet was continuously fed, and at its interface, pressure and heat fusion were performed to obtain a flame-retardant heat-insulating waterproof rubber sheet exposed to the outside world.

FIG. 2 is a cross-sectional view of the thus exposed outside flame-retardant heat-insulating waterproof rubber sheet 20 . In FIG. 2, 1 is a foamed polyethylene sheet, and 23 is a yellow vulcanized chlorosulfonated polyethylene rubber sheet having an oxygen index of 36.

Comparative Example 1 Ethylene / propylene / diene rubber was kneaded with an appropriate amount of a vulcanizing agent, a vulcanization accelerator, a lubricant, a filler and an antioxidant with a Banbury mixer or the like to obtain an unvulcanized rubber compound. A rubber compound is made into a sheet having a thickness of 1 mm by a calender roll, and then the sheet is vulcanized by a continuous vulcanizer at high temperature and high pressure to obtain a black vulcanized ethylene / propylene / diene rubber sheet.

This black vulcanized ethylene / propylene / diene rubber sheet has an oxygen index of 18 measured according to JIS-K-7201.

Next, while continuously feeding the obtained black vulcanized ethylene / propylene / diene rubber sheet, it is preheated to 120 ° C at which the polyethylene foam sheet is softened, and then the heated black vulcanized ethylene / propylene / diene rubber sheet is At the same time as sending to the hot roll side of the pressure roll consisting of the 120 ° C hot roll and the room temperature cooling roll, at the same time continuously feeding the expanded polyethylene sheet with a thickness of 4mm to the cooling roll side, pressurizing and heat By heat-sealing, a heat-insulating waterproof rubber sheet exposed to the outside was obtained.

FIG. 3 is a transverse cross-sectional view of the exposed outside heat-insulating waterproof rubber sheet 20 thus obtained. In FIG. 3, 1 is a polyethylene foam sheet, 2 is a waterproof rubber sheet having an oxygen index of 18, and in this case is a black vulcanized ethylene / propylene / diene rubber sheet.

Comparative Example 2 An externally exposed heat-insulating waterproof rubber sheet was obtained in the same manner as in Comparative Example 1 except that a black vulcanized ethylene / propylene / diene rubber sheet having an oxygen index of 23 was used.

Next, various flame resistance tests were carried out on each of the exposed outside heat-insulating waterproof rubber sheets thus obtained.

Table 1 shows the test results.

The test method was as follows.

(1) Oxygen index The oxygen index was measured according to JIS-K-7201.

(2) Flash point Flash point is based on NBS method, step-up temperature rise, 30kv
Measured with a spark source.

(3) Flame-extinguishing time and combustion length As shown in Fig. 4, a slate plate with a width of 30 mm and a length of 250 mm is attached to an outside exposed heat-insulating waterproof rubber sheet with a width of 25 mm and a length of 200 mm and an outside exposed flame-retardant heat-insulating waterproof. The rubber sheets 20 are attached to each other so that the waterproof rubber sheet side is exposed to the outside air and the foamed plastic sheet 1 side is the slate plate 3 as a test sample. Next, these test samples were horizontally installed in a draft with a wind speed of 0.5 m / sec, and the extinction time and the combustion length were measured when the Bunsen burner 4 continued to ignite from one end side in the longitudinal direction.

As can be seen from Table 1, the externally exposed heat-insulating waterproof rubber sheets of Comparative Examples 1 and 2 have the results of a low ignition point, a long flame extinction time, and a long combustion length.

On the other hand, the externally exposed flame-retardant heat-insulating waterproof rubber sheets of Examples 1 to 4 have a high ignition point, a short flame-extinguishing time, and a short combustion length, and exhibit excellent fire spread prevention properties. I understand that

[Advantages of the Invention] The externally exposed flame-retardant heat-insulating waterproof rubber sheet of the present invention has a high ignition point, a short flame-extinguishing time, and a short burning length, and as a result, exhibits excellent fire spread prevention properties. Above useful.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an externally exposed flame-retardant heat-insulating waterproof rubber sheet of Example 1, FIG. 2 is a cross-sectional view of an externally-exposed flame-retardant insulating waterproof rubber sheet of Example 4, and FIG. FIG. 4 is a cross-sectional view of a conventional heat-insulating waterproof rubber sheet, and FIG. 4 is a perspective explanatory view of a combustion test. 1: Foamed polyethylene sheet, 2: Waterproof rubber sheet, 3: Slate plate, 4: Bunsen burner, 20 : Externally exposed flame-retardant heat-insulating waterproof rubber sheet, 22: Black vulcanized ethylene / propylene / diene with an oxygen index of 25 Rubber sheet, 23: oxygen index 36
Yellow vulcanized chlorosulfonated polyethylene rubber sheet.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshitaka Fujii 3-1-1 Sukegawa-cho, Hitachi City, Ibaraki Hitachi Cable Company Ltd. (72) Inventor Fumifumi Nara 3-1-1 Sukegawa-cho, Hitachi City, Ibaraki Prefecture No. 1 Inside the Electric Cable Factory (72) Inventor Norihisa Suzuki 3-1-1 Sukegawa Town, Hitachi City, Ibaraki Inside the Electric Cable Factory, Hitachi Cable (56) Reference JP-A-57-127055 (JP, A) Actual opening 50-44813 (JP, U) Actual opening 52-129199 (JP, U) Actual opening 58-107831 (JP, U) Actual opening 59-177616 (JP, U)

Claims (1)

[Claims] 1. JIS-K-720 on a foamed plastic sheet
An externally exposed flame-retardant heat-insulating waterproof rubber sheet, which is formed by laminating and integrating a flame-retardant waterproof rubber sheet having an oxygen index of 25 or more measured according to 1.