JP2006252892A - Nonflammable cover material for lighting, illumination cover, and illuminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material that satisfies the standards for noninflammability requested of a material for a railway vehicle, further has light transmission properties for enabling the material to be used as a cover material for lighting, and can be used appropriately for the cover material for lighting, or the like. <P>SOLUTION: The inflammable cover material for lighting is made of fluororesin, having an inorganic base as a support, the inorganic base is a glass cloth, and the fluororesin has a limiting oxygen index of 90 or higher. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a nonflammable lighting cover material, and a lighting cover and a lighting device using the same.

For fire fighting of railway vehicles, the Ministry of Land, Infrastructure, Transport and Tourism stipulates flammability standards for railway vehicle materials by classifying them into non-flammable, extremely incombustible, and incombustible. “For Fire Accident Countermeasures” (see Non-Patent Document 1, for example). Recently, in December 25, 2001, Ministry of Land, Infrastructure, Transport and Tourism No. 151 “Ministerial Ordinance for Establishing Technical Standards on Railways”, the ceiling inside railway vehicles, which is the cause of the spread of fires in railway fires, to strengthen the prevention of railway vehicle fires. Regarding the parts, regulations will be strengthened from conventional flame retardant to non-flammable, and the addition of judgment on melt dripping resistance will be established on March 8, 2002. Reflected in “Interpretation Standards for Ministerial Ordinances” (JNR 157, March 8, 2002), it was announced on December 27, 2004.

In this flammability standard, the ceiling part inside the railway vehicle includes lighting. Conventionally, an acrylic resin or a polycarbonate resin imparted with flame retardancy has been used as the lighting cover. However, lighting covers made of these resins have a problem that they do not satisfy the non-flammable standards even if they meet the conventional flame retardant standards.

For example, an inorganic substrate such as an aluminum plate can be considered as a material having high incombustibility, but such an inorganic substrate alone is not suitable for a lighting cover that requires transparency.

A light diffusing material made of a glass fiber fabric and a fluororesin and a lighting device using the same are disclosed (for example, see Patent Document 1). Regarding this light diffusing material, Patent Document 1 has a description that it is excellent in nonflammability and antifouling property, but there is a problem that it does not satisfy the nonflammability standard for railway vehicle materials. Moreover, although the heat-resistant light-diffusion sheet for lighting fixtures which consists of a glass fiber sheet and a fluororesin sheet | seat is disclosed (for example, refer patent document 2), the judgment of nonflammability is judged only by self-combustibility, There is a problem that the non-combustible standard for railway vehicle materials is not satisfied.

Although incombustible materials for vehicles made of glass fiber fabric and fluororesin have been disclosed (see, for example, Patent Document 3), no specific study has been made on translucency.
Moreover, the nonflammable fabric which consists of glass fiber and a fluororesin is disclosed (for example, refer patent document 4). This non-combustible fabric is not ignited and ignited in the ethyl alcohol combustion flame test, and there is no or little smoke. However, since the fluororesin is unfired, it is cloudy, and the translucency is specific. Although it has not been examined, it is considered to be low. Further, there is also a problem that the fluororesin easily falls off when it is not fired.
JP 2001-55646 A (Claim 1, Example) JP 2002-221609 A JP-A-7-101335 JP-A-8-144173 “Railway Fire” [online], Internet <URL: http: // www1. odn. ne. jp / ˜aaa81350 / kaisetu / kasai / kasai. htm>

It is generally known that fluororesins have high flame retardancy. However, since the fluororesin has a high linear expansion coefficient, volume expansion occurs during heating. This volume expansion is judged as “melting dripping” for the “nonflammability” of the cabin ceiling material among the flammability standards for railway vehicle materials. The standard cannot be met.

On the other hand, the inorganic base material itself is nonflammable, but when it is a single inorganic base material, the flame penetrates the void when exposed to the flame. In order to prevent this, it is necessary to increase the density, but in that case, the translucency is lowered, and nonflammability and translucency as a flammability standard for railcar materials are obtained at the same time. I couldn't.

The present invention prevents the expansion caused by heating, which is a drawback of the fluororesin alone, by using the inorganic base material as a support, and also eliminates the disadvantage of the inorganic base material alone, thereby producing a material for railway vehicles. Provided is a non-combustible lighting cover material that satisfies the required non-combustible standard and further has translucency that can be used as a lighting cover by firing a fluororesin. Is.

The present invention is a cover material for nonflammable lighting characterized by comprising an inorganic base material as a support and comprising a fluororesin.
The present invention is a railcar lighting cover comprising the nonflammable lighting cover material.
The present invention is a lighting cover that is a building lighting cover, an aircraft lighting cover, a vehicle lighting cover, or a marine lighting cover, wherein the lighting cover uses the nonflammable lighting cover material of the present invention. It is the lighting cover characterized by becoming.
The present invention is a lighting device having a lighting cover, wherein the lighting cover is the railcar lighting cover or the lighting cover.
The present invention is described in detail below.

The cover material for incombustible lighting of the present invention satisfies the “incombustible” combustibility standard required for the ceiling part inside a railway vehicle according to the above-mentioned Iron Transport No. 81, Ministry of Land, Infrastructure, Transport and Tourism No. 151 and JNR No. 157. It also satisfies the melt dripping resistance according to the standard.
In the present invention, the determination criteria for melt dripping take into account not only the presence or absence of dripping but also the surface condition after the combustion test. Specifically, it is determined that a material having no dripping and dripping and having a smooth surface state even after a combustion test has resistance to melting and dripping.

The nonflammable lighting cover material of the present invention also has light characteristics suitable for use as a lighting cover material.

The cover material for nonflammable lighting of the present invention usually has translucency, and the total light transmittance can be 45% or more. In particular, when a glass cloth having a total light transmittance of 45% or more is used as a glass cloth described later, the total light transmittance within the above range can be easily achieved.
The total light transmittance of the nonflammable lighting cover material is preferably 50% or more, and more preferably 55% or more.

In general, as the illumination cover, a light diffusing property, that is, a material having a high haze value while having sufficient translucency is preferred. The cover material for incombustible lighting of the present invention may have a haze value of 60% or more, 70% or more, or 80% or more, depending on the application.
In this specification, the total light transmittance and the haze value are values obtained by measuring according to ASTM D1003 using Hazeguard II (manufactured by Toyo Seiki Seisakusho).

The incombustible lighting cover material of the present invention is made of a fluororesin using an inorganic base material as a support.
Since the incombustible lighting cover material of the present invention is made of a fluororesin, it not only satisfies the above-mentioned “incombustible” flammability standard and melt dripping resistance, but in addition to translucency, stain resistance and Excellent weather resistance.

Examples of the fluorine resin in the nonflammable lighting cover material include chlorotrifluoroethylene [CTFE] copolymer resin; trifluoroethylene copolymer resin; polytetrafluoroethylene [PTFE] resin; hexafluoropropylene [HFP]. Copolymer resin; Vinylidene fluoride [VdF] copolymer resin; Tetrafluoroethylene [TFE] / perfluoro (alkyl vinyl ether) [PAVE] copolymer resin [PFA]; Tetrafluoroethylene [TFE] / HFP copolymer Copolymer resin such as coalescence [FEP] resin;
In this specification, the term “polytetrafluoroethylene resin” uses the term “polytetrafluoroethylene” for convenience, but the fluoropolymer constituting the polytetrafluoroethylene resin is tetrafluoroethylene [TFE]. It is not limited to a homopolymer, but may be modified polytetrafluoroethylene [modified PTFE] obtained by polymerizing TFE and a comonomer.
The cover material for nonflammable lighting of the present invention may have only one type of the fluororesin, or may have two or more types of the fluororesin.

The fluororesin in the present invention is preferably a baked fluororesin from the viewpoint of obtaining a material excellent in translucency.
The firing of the fluororesin will be described later.

As the fluororesin, those having a high critical oxygen index are preferred from the viewpoint of non-combustibility. The critical oxygen index is preferably 90 or more, and more preferably 95 or more. When using a low critical oxygen index, there is a problem that in addition to the incombustibility, there is a problem that the amount of smoke generated at the time of flame contact in the combustion test increases.
The above-mentioned critical oxygen index is a number indicating how much oxygen is present in the atmosphere and the material (test object) continues to burn without disappearing in the atmosphere. The larger the number, the more the material burns. Means difficult. In this specification, the limiting oxygen index is measured in accordance with ASTM D-2863.
Examples of the fluororesin having a critical oxygen index within the above range include PTFE resin, PFA resin, FEP resin, and the like. Among these, PTFE resin that has a very high melt viscosity and does not exhibit melt fluidity even at a melting point or higher is preferred in view of resistance to melt and dripping.

The cover material for nonflammable lighting of the present invention uses an inorganic base as a support.
The inorganic base material is preferably a porous body in terms of translucency and carrying a fluororesin. The porous body here has a void in the inorganic base material itself, and examples thereof include woven fabric, non-woven fabric, and felt.
Examples of the inorganic base material include glass, rock wool, stainless steel, iron, and the like, and a glass cloth is preferable in terms of translucency.
The glass cloth is preferably a woven fabric from the viewpoint of strength.

As said glass cloth, it is preferable to use a thing with a high total light transmittance at the point which improves the translucency of the cover material for nonflammable lighting obtained, and what is 45% or more is preferable, and is 50% or more. Some are more preferable, and 55% or more is still more preferable.

In order to obtain strength as a fiber, a glass sizing agent is usually used for the glass fiber used for the glass cloth, but the sizing agent may cause smoke during combustion. Carbonization may occur during heat treatment. When using the glass cloth in the present invention, it is preferable to remove the bundling material by heat cleaning so that these problems do not occur.
In addition, the glass cloth may be surface-treated using silane coupling or the like to improve wettability, but it may cause fuming, coloring, etc. as in the case of the sizing agent. It is preferable to use a glass cloth that has not been surface-treated.

The thickness of the incombustible lighting cover material of the present invention is not particularly limited as long as the incombustibility and translucency are ensured. Moreover, even if the cover material for nonflammable lighting of this invention is the same thickness, various physical-property values may differ according to the kind of glass fiber, the weaving method, the kind of fluororesin, those combinations, etc. However, the above-mentioned thickness is usually 1 mm or less, preferably 500 μm or less, in terms of difficulty in securing translucency when it is thick, and problems such as increased weight and shape flexibility when making a lighting cover. Preferably it is 300 micrometers or less.
The lower limit of the thickness is preferably 20 μm, more preferably 50 μm, considering the strength when used alone, ease of processing, and the like.
The cover material for incombustible lighting of the present invention has a thickness that is supported by an inorganic base material even in a molten state so as not to cause melt dripping when a fluororesin having a melt fluidity such as PFA resin or FEP resin is used. For example, it is desirable that the thickness of one surface from the glass cloth surface at room temperature is 100 μm or less, preferably 50 μm or less, more preferably 25 μm or less.

The incombustible lighting cover material of the present invention can be prepared by impregnating a fluororesin into an inorganic base material, or can be prepared by laminating a sheet made of a fluororesin on an inorganic base material. It can also be created by combining each creation method.
The nonflammable lighting cover material of the present invention is preferably prepared by impregnating a dispersion made of a fluororesin into an inorganic base material, drying and firing, in view of ease of molding processing, cost, and the like.
In the present invention, when a PTFE resin is used as the fluororesin, lamination of the PTFE resin sheet and the inorganic base material may be difficult to weld due to the melt viscosity of the resin. A method combining impregnation and lamination is also possible, but it is difficult to ensure superiority over impregnation alone in terms of ease of molding and cost.

The impregnation can be performed by a known method.
The impregnation is preferably performed in terms of the ratio of the mass of the fluororesin in the incombustible lighting cover material obtained (hereinafter, this ratio is also referred to as “fluorine resin content”) in terms of incombustibility and translucency. 10% or more and 80% or less, more preferably 30% or more and 70% or less, and further preferably 40% or more and 65% or less.

As described above, the cover material for nonflammable lighting of the present invention can be prepared by impregnating, drying and firing.
The firing is performed by adjusting the temperature and time so that the fluororesin used has a melting point or higher. Moreover, it is preferable that the upper limit of the firing temperature of the fluororesin is not more than a temperature at which a large amount of decomposition does not occur. As a firing method, it is preferable to set the furnace temperature to about 20 to 50 ° C. higher than the melting point of the fluororesin, and to set the residence time so that the inside is sufficiently higher than the melting point temperature.

When the cover material for nonflammable lighting of the present invention is produced by preparing a sheet made of a fluororesin in advance, the sheet is usually laminated on a glass cloth, and then the fluororesin abruptly exceeds the melting point of the fluororesin. It can be performed by heat fusion at a temperature that is less than the temperature at which thermal decomposition begins.

A lighting cover that is a building lighting cover, an aircraft lighting cover, a vehicle lighting cover, or a marine lighting cover, wherein the lighting cover is made of the above-described nonflammable lighting cover material of the present invention. The lighting cover is also one aspect of the present invention.
A railcar lighting cover comprising the above-described incombustible lighting cover material of the present invention is also one aspect of the present invention.

The lighting cover including the railcar lighting cover according to the present invention is made of the above-described non-combustible lighting cover material according to the present invention. And weather resistance is high and it is lightweight.
Of the lighting covers of the present invention, the building for which the building lighting cover can be used is not particularly limited, and examples thereof include houses, buildings, stores, hotels, gymnasiums, and the like. The vehicle that can be used is not particularly limited, and examples thereof include automobiles, buses, and monorails.
The shape of the lighting cover including the railcar lighting cover of the present invention is not particularly limited as long as it has a thickness in the same range as the above-described nonflammable lighting cover material of the present invention.

A lighting device having a lighting cover, wherein the lighting cover is the lighting cover of the present invention, is also one aspect of the present invention.
A railcar lighting device having a lighting cover, wherein the lighting cover is the railcar lighting cover of the present invention, is also one of the present inventions.
The lighting device including the lighting device for a railway vehicle according to the present invention is not particularly limited as long as it has the above-described lighting cover. For example, the lighting device may cover the lighting so as to cover the whole, or may be partially The cover may be covered so as to cover, or the design may be added like indirect illumination.

Since the cover material for nonflammable lighting of the present invention has the above-described configuration, it is nonflammable, and has high translucency, antifouling properties and weather resistance, and is a lightweight railcar lighting cover, and for buildings. It is useful as a material for various lighting covers for aircraft, vehicles and ships.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited only to these Examples and Comparative Examples.

Example 1
A glass cloth (WCA-116E107B, manufactured by Nitto Boseki Co., Ltd.) having the physical properties shown in Table 1 is impregnated in an aqueous PTFE dispersion (polyflon PTFE dispersion D-2E, manufactured by Daikin Industries, Ltd.), and excess liquid is removed by a doctor bar. After drying for 5 minutes by infrared drying set at 100 ° C., then baking for 5 minutes in an electric furnace set at 380 ° C., taking out from the electric furnace, cooling, and a sheet of glass cloth and fluororesin Obtained.

Example 2
In the same manner as in Example 1, impregnation, drying and firing were repeated three times to obtain a sheet made of glass cloth and fluororesin.

Comparative Example 1
4 kg of PTFE resin powder (New Polyflon PTFE M-111, manufactured by Daikin Industries) was put into a mold having a diameter of 106 mm, and compression molding was performed at a molding pressure of 20 Mpa to obtain a preform. The obtained preform was heated from normal temperature to 365 ° C. at 50 ° C./hour, held at 365 ° C. for 10 hours, and then cooled to normal temperature at 50 ° C./hour to obtain a PTFE fired molded body.
This fired molded body was skived to obtain a PTFE sheet.

Comparative Example 2
A sheet made of glass cloth and fluororesin was obtained in the same manner as in Example 1 except that firing in an electric furnace was not performed. The fluororesin of this sheet was unfired.

(Evaluation)
About the sheet | seat obtained from each Example and the comparative example, various measurements were performed in the following procedure.
1. It was measured with a thickness thickness gauge (manufactured by Mitutoyo Corporation).
2. Fluororesin content The difference between the mass (a) of the obtained sheet and the mass (b) of the glass cloth before impregnation was calculated as the resin amount by the following formula.

3. Total light transmittance and haze value Haze guard II (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used and measured according to ASTM D1003.
The measurement results of 1 to 3 are shown in Table 1.

Each of the sheets in each example had a high total light transmittance and a high haze value, and was lightweight. On the other hand, the sheet of Comparative Example 2 in which the fluororesin has not been fired is white and does not have a sufficient total light transmittance, and the fluororesin can easily fall off when measuring translucency, so that it can wipe off dirt, etc. It could not withstand actual use.

4). The flammability test for railway vehicle materials This test was stipulated in May 81, 1992, on Railways No. 81 “Train Fire Accident”.
(1) The B5-size test material (182 mm × 257 mm) shown in FIG. 1 is held at a 45 ° inclination, and the center of the bottom of the fuel container is 25.4 mm (1 inch) vertically below the center of the lower surface of the test material. ), Placed on a base of a material with low thermal conductivity (cork, etc.), ignited with 0.5 ml of pure ethyl alcohol, and allowed to stand until the fuel burned out.
The inside of the test chamber was maintained at a temperature of 15 to 30 ° C. and a humidity of 60 to 75%, and no air flow was maintained.
If the specimen is a hygroscopic material, the sample finished to the above specified size should be separated from the floor by 1 m or more in a breathable room, away from direct sunlight, and allowed to elapse for 5 days or more. I kept it.

(2) Combustibility judgment is divided into pure ethyl alcohol during combustion and after combustion. During combustion, the ignition, ignition, smoke generation, flame condition, etc. of the test material are visually observed and After that, the residual flame, residual dust, carbonization and deformation state are visually observed.
Table 2 shows the flammability criteria.

From this test, the sheet of each example was found to be nonflammable. On the other hand, in the PTFE sheet of Comparative Example 1, the expansion due to the temperature rise is determined to be melt dripping, and due to the expansion, a part of the sheet comes into contact with the alcohol container, and the part is perforated, and nonflammability is not obtained. It was.

The nonflammable lighting cover material of the present invention is nonflammable because it has the above-described configuration, and has a high light-transmitting property, antifouling property and light resistance, and a lightweight railcar lighting cover, and construction. It is useful as a material for various lighting covers for objects, aircraft, vehicles and ships.

It is an instrument used in the flammability test for railway vehicle materials.

Explanation of symbols

1 Specimen (size: B5)
2 Alcohol container (made of iron, 17.5φ × 7.1, 0.8t)
3 container stand

Claims (11)

An incombustible lighting cover material comprising an inorganic base material as a support and made of a fluororesin. The cover material for nonflammable lighting according to claim 1, wherein the inorganic base material is a glass cloth. The cover material for nonflammable lighting according to claim 1 or 2, wherein the fluororesin has a limiting oxygen index of 90 or more. 4. The nonflammable lighting cover material according to claim 1, wherein the fluororesin is a polytetrafluoroethylene resin. The cover material for nonflammable lighting according to claim 1, 2, 3, or 4, wherein the dispersion is made by impregnating a dispersion made of a fluororesin with an inorganic base material, followed by drying and firing. The incombustible lighting cover material according to claim 1, 2, 3, 4, or 5, wherein the incombustible lighting cover material has a total light transmittance of 45% or more. The incombustible lighting cover material according to claim 1, 2, 3, 4, or 5, wherein the incombustible lighting cover material has a haze value of 60% or more. A lighting cover for a railway vehicle comprising the nonflammable lighting cover material according to claim 1, 2, 3, 4, 5, 6 or 7. A lighting cover that is a building lighting cover, an aircraft lighting cover, a vehicle lighting cover, or a marine lighting cover,
The lighting cover is made of the nonflammable lighting cover material according to claim 1, 2, 3, 4, 5, 6 or 7. A railway vehicle lighting device having a lighting cover,
The railway vehicle illumination device according to claim 8, wherein the illumination cover is a railway vehicle illumination cover. A lighting device having a lighting cover,
The lighting device according to claim 9, wherein the lighting cover is the lighting cover according to claim 9.

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