JP2002069403A - Fire-resistant non-woven adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire-resistant non-woven adhesive sheet that has a good fire-retardancy and adhesiveness and also produces a reduced amount of poisonous halogen gas on combusion. SOLUTION: The fire-resistant non-woven adhesive sheet has at least an adhesive layer on one side of a fire-resistant non-woven cloth containing flame retarder and the flame retarder is a halogen-free agent and a content of halogen is not more than 5% by weight of the adhesive sheet. The adhesive sheet has an excellent fire-resistance and adhesive character and also produces reduced poisonous halogenic gas on combustion. The flame retardancy of the sheet becomes better by adding the non-halogen flame retarder to the adhesive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a nonwoven fabric flame-retardant pressure-sensitive adhesive sheet. More specifically, the present invention relates to a nonwoven fabric flame-retardant pressure-sensitive adhesive sheet having both excellent flame retardancy and adhesiveness, and generating less toxic halogen-based gas during combustion.

[0002]

2. Description of the Related Art Conventionally, nonwoven fabric flame-retardant pressure-sensitive adhesive sheets have been used for sound,
In the fields of home appliances, automobiles and OA equipment, dustproof, blindfold,
It is widely used for applications such as light shielding, burn prevention, chatter prevention and various buffer packings. In general, halogen-based flame retardants have been used in conventional nonwoven fabric flame-retardant pressure-sensitive adhesive sheets. Nonwoven fabric flame-retardant pressure-sensitive adhesive sheets containing halogen-based flame retardants generate toxic halogen-based gases when burned. For this reason, from the viewpoint of environmental protection or safety, there has recently been a movement to restrict the use of nonwoven fabric flame-retardant pressure-sensitive adhesive sheets that generate toxic halogen-based gas during combustion.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a non-woven flame-retardant pressure-sensitive adhesive sheet which has excellent flame retardancy and adhesiveness and generates little toxic halogen-based gas during combustion.

[0004]

Means for Solving the Problems The present inventors provide a non-woven flame-retardant pressure-sensitive adhesive sheet comprising a flame-retardant non-woven fabric containing a flame retardant and having an adhesive layer provided on at least one surface thereof. The problem has been solved by providing a nonwoven fabric flame-retardant pressure-sensitive adhesive sheet using a nonwoven fabric containing a halogen-based flame retardant.

[0005] The non-woven flame-retardant pressure-sensitive adhesive sheet of the present invention preferably has a halogen element content of 5% by mass or less. It is still more preferable that the content is 1% by mass, and the most preferable is that it contains no halogen element. If it exceeds 5% by mass, toxic halogen-based gas generated during combustion increases, which is not preferable.

Hereinafter, the nonwoven fabric flame-retardant pressure-sensitive adhesive sheet of the present invention will be described in more detail based on its structure. 1. Nonwoven Fabric The halogen content of the nonwoven fabric used in the present invention is preferably 5% by mass or less. As the fiber which is a main component of the nonwoven fabric, specifically, for example, silk, wool, cotton, hemp,
Natural fibers such as cellulose and its derivatives, rayon, partially formalized polyvinyl alcohol, polyester, polyamide, polyamideimide, polyimide, polyurethane, acrylic resin, polyacrylonitrile,
Synthetic fibers such as polyethylene, polypropylene, and carbon fibers can be used. These may be used alone or as a mixture.

[0007] 2. Non-Halogen Flame Retardant In the present invention, “non-halogen” means that the chemical structure does not contain a halogen element. Therefore, it does not exclude a trace amount of a halogen element derived from impurities or a catalyst. Examples of the non-halogen flame retardant include a silicone compound, a hydrated metal compound, a phosphorus compound, a nitrogen-containing compound, a metal oxide, a borate compound, and a tin compound. Specifically, for example, high molecular weight silicone oil, silicone polymer, silicone compounds such as fumed silica, aluminum hydroxide, hydrated metal compounds such as magnesium hydroxide, red phosphorus, ammonium polyphosphate, guanidinium phosphate, Phosphorus compounds such as phosphate esters, urea and its compounds, melamine compounds,
Examples include nitrogen-containing compounds such as guanidine compounds, metal oxides such as zinc oxide, tin oxide, iron oxide, and copper oxide; boric acid compounds such as zinc borate and boric acid; and zinc stannate.

[0008] 3. Flame-retardant non-woven fabric In order to make the non-woven fabric contain a flame retardant, the surface of the fibers constituting the non-woven fabric is coated with a composition comprising the above-described flame retardant and a binder resin, or when the fibers are synthetic fibers, A flame retardant may be dispersed in the oil. There is also a method in which a flame retardant is bonded to fibers of a nonwoven fabric by a chemical reaction. The content of the non-halogen flame retardant contained in the flame-retardant nonwoven fabric is preferably 5 to 50% by mass of the flame-retardant nonwoven fabric, and more preferably 10 to 40% by mass.

4. Pressure-sensitive adhesive layer The pressure-sensitive adhesive used in the present invention is not particularly limited, and known acrylic, rubber-based, and silicone-based pressure-sensitive adhesives can be used. The pressure-sensitive adhesive has a halogen element content of 5% by mass or less. Is preferred. The pressure-sensitive adhesive layer may not contain a flame retardant, or may contain a flame retardant for the purpose of further improving the flame retardancy of the nonwoven flame-retardant pressure-sensitive adhesive sheet. As the flame retardant in this case, a non-halogen flame retardant to be contained in the flame-retardant nonwoven fabric can be used. When the flame retardant is added to the pressure-sensitive adhesive layer, the addition amount is 80% by mass or less, preferably 60% by mass or less of the pressure-sensitive adhesive layer.

In order to form a pressure-sensitive adhesive layer on one side or both sides of the flame-retardant nonwoven fabric, the pressure-sensitive adhesive composition may be applied directly to the flame-retardant nonwoven fabric. One side of the double-sided pressure-sensitive adhesive sheet may be bonded.

5. Applications of nonwoven fabric flame-retardant pressure-sensitive adhesive sheet The nonwoven fabric flame-retardant pressure-sensitive adhesive sheet of the present invention can be used for labels, stickers, dust-proof, concealment, light-shielding, burn prevention, in various fields such as acoustic products, home appliances, automobiles, OA equipment, and building materials. In addition to being used for applications such as cushioning packing and interior materials for construction such as decorative sheets, double-sided pressure-sensitive adhesive sheets are particularly used for bonding and fixing members near heating elements such as electronic / electric devices and automobiles.

[0012]

The present invention will be described more specifically with reference to the following examples and comparative examples. Unless otherwise specified, parts and% represent parts by mass and% by mass, respectively.

<Preparation of pressure-sensitive adhesive composition> 2-ethylhexyl acrylate 50 parts n-butyl acrylate 46 parts acrylic acid 3.5 parts 2-hydroxyethyl acrylate 0.5 part 2,2'-azobisisobutyronitrile 0 .2 parts Ethyl acetate 100 parts The above mixture was stirred at 80 ° C. for 8 hours in a nitrogen stream to polymerize the acrylic monomer, solid content 50%, mass average molecular weight 4
100,000 acrylate copolymer solution was obtained.

The above-mentioned acrylate copolymer solid content 1
To 00 parts, a tackifying resin, a non-halogen flame retardant, and a crosslinking agent were blended in the proportions shown in Table 1, and dissolved in toluene to prepare pressure-sensitive adhesive compositions A to C having a solid content concentration of 50%. . However, the amount of the epoxy crosslinking agent in Table 1 is
It was expressed in parts by mass of a 0.5% solution.

[0015]

[Table 1]

The symbols in Table 1 are as follows. : Polymerized rosin pentaerythritol ester ("Pentalin C-J" manufactured by Rika Hercules): Terpene phenol copolymer ("YP-90LL" manufactured by Yashara Chemical Co.): Ammonium polyphosphate ("Terage 60" manufactured by Chisso): Hydroxic acid Aluminum (Showa Denko “H-32”): Melamine cyanurate (Nissan Chemical Industries “MC-6”
10)): "E-05X" manufactured by Soken Chemical Co. (solid content 0.5%)

<Preparation of Nonwoven Adhesive Sheet> The pressure-sensitive adhesive compositions A to C were applied to release paper so that the weight of the pressure-sensitive adhesive layer per unit area after drying was 60 g / m ² and dried. Example 1 by laminating on one side of the nonwoven fabric described in
To 3, the nonwoven fabric flame-retardant pressure-sensitive adhesive sheets of Comparative Examples 1 and 2, and the nonwoven fabric nonflammable pressure-sensitive adhesive sheet of Comparative Example 3 were obtained.

<Test Method and Evaluation Criteria of Measurement Results> The nonwoven fabric flame-retardant pressure-sensitive adhesive sheets and nonwoven fabric non-flame-retardant pressure-sensitive adhesive sheets of Examples 1 to 3 and Comparative Examples 1 to 3 were produced by the following methods according to the following methods. The amount, flammability test, and oxygen index were measured and evaluated. The measurement method and the evaluation criteria for the measurement result are as follows.

<Adhesive force> The nonwoven fabric pressure-sensitive adhesive sheet was pressed using a 2 kg manual pressing roller at a pressing speed of about 20 mm / sec.
c. The film was affixed to the SUS plate with one reciprocating pressure, and after 30 minutes, the 180 ° peel adhesion was measured at a tensile speed of 300 mm / min. If it is 5 N / 25 mm or more, it is determined that there is practical adhesive strength.

<Amount of Halogen Gas Generated During Burning> 20 mg of the nonwoven fabric pressure-sensitive adhesive sheet was burned in an oxygen atmosphere of a combustion flask, and the generated gas was absorbed into 20 ml of an absorbing solution (ultra pure water), and the amount of halogen was determined by ion chromatography. .

<Combustion test> UL-94HBF / HF-2
A horizontal combustion test was carried out according to / HF-1, and when it conformed to HF-1, which is required to satisfy all of the following A to E, it was determined that it had flame retardancy. A: Any part of the four specimens of each set of five specimens emits a flame for more than 2 seconds after removing the test flame and does not continue to burn. B: No part of any test piece emits flame for more than 10 seconds after removing the test flame and does not keep burning. C: None of the test pieces burned to a distance exceeding 60 mm from the terminal exposed to the test flame. D: None of the specimens drip the flaming particles that ignite the dry surgical cotton 175 mm below the test flame. E: Flameless combustion after removing any test flame
Does not last more than 30 seconds, does not exceed 60 mm.

<Oxygen Index> The oxygen index was measured according to JIS K7201. The oxygen index is the minimum oxygen concentration that represents the amount of oxygen required for the test sample to sustain combustion under the test conditions specified in the standard by volume%,
When the numerical value exceeds 21, it was determined that there was flame retardancy. Tables 2 and 3 show the results of the tests and their evaluations.

[0023]

[Table 2]

[0024]

[Table 3]

The nonwoven fabrics shown in Tables 2 and 3 are as follows. : Non-halogen flame-retardant rayon nonwoven fabric (“ULH-NH N7775B” manufactured by Ambic, thickness: 0.9 m)
m, containing non-halogenated organic phosphorus and nitrogen flame retardant, chlorine content:
0.2% or less): Non-halogen flame-retardant rayon nonwoven fabric ("DS-90HK" manufactured by Japan Vilene Co., Ltd.), thickness: 0.9 mm, containing non-halogen organic phosphorus-nitrogen flame retardant, chlorine content: 0.2 %): Rayon nonwoven fabric containing chlorine-based flame retardant (“ULH N9795B” manufactured by Ambic, thickness: 0.9 mm, chlorine content: 24.5%): Polyester-cellulose-modified polyvinyl alcohol-based nonflammable nonwoven fabric ( "DS-9" manufactured by Japan Vilene
"SS", thickness: 0.9 mm) The "halogen amount" in Table 2 indicates the mass ratio of halogen gas generated during combustion to the test sample mass.
In addition, in the halogen analysis of this example and the comparative example, only chlorine was detected.

From the results shown in Table 2, it can be seen that Examples 1 to 4 generate a small amount of halogen gas during combustion and have high adhesive strength and flame retardancy. On the other hand, Comparative Examples 1 and 2 in Table 3 have the same adhesive strength and flame retardancy as the Examples, but generate a large amount of halogen gas during combustion, while Comparative Example 3 generates halogen gas during combustion. It can be seen that the occurrence of cracks is small and the adhesive strength is high, but the flame retardancy is poor. Since the nonwoven fabric flame-retardant pressure-sensitive adhesive sheet of the present invention has a small halogen element content, the amount of halogen gas generated during combustion is small. Therefore, it can be said that the generation amount of halogen-based toxic gas such as dioxin is small.

The nonwoven fabric flame-retardant pressure-sensitive adhesive sheet of the present invention has both excellent flame retardancy and adhesiveness, and exhibits a remarkable effect that a small amount of toxic halogen gas is generated during combustion.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D06M 13/432 D06M 11/08 15/263 11/10 F term (Reference) 4F100 AA03A AA04A AA17A AA19 AA20A AA32A AH03A AH07 AJ05 AK25 AK52A AL01 AR00B AR00C BA03 BA06 BA10B BA10C CA08A CA08B CA08C CA16B CA16C DG15A GB33 GB48 GB81 JJ07 JL11B JL11C YY00A 4J004 AA05 AA10 AA11 AA17 AA18 BA01 CA03 CA03 CA04 CA03 FA03 DA16 4L033 AA02 AB07 AC05 AC11 BA39 BA79 CA18 DA04

Claims (4)

[Claims] 1. A flame-retardant pressure-sensitive adhesive sheet comprising a flame-retardant nonwoven fabric containing a flame-retardant and a pressure-sensitive adhesive layer provided on at least one side, wherein the flame-retardant is a non-halogen flame retardant. Adhesive sheet. 2. The nonwoven flame-retardant pressure-sensitive adhesive sheet according to claim 1, wherein the halogen element content is 5% by mass or less. 3. The non-halogen flame retardant, wherein the chemical structure does not contain a halogen element in a silicone compound, a hydrated metal compound, a phosphorus compound, a nitrogen-containing compound, a metal oxide, a borate compound, and tin. The nonwoven fabric flame-retardant pressure-sensitive adhesive sheet according to claim 1, which is a compound. 4. The pressure-sensitive adhesive layer according to claim 1, wherein the pressure-sensitive adhesive layer contains a non-halogen flame retardant.
Item 10. The nonwoven fabric flame-retardant pressure-sensitive adhesive sheet according to item 8.