JP2002121508A - Flame-retardant pressure-sensitive adhesive tape for protective covering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame-retardant pressure-sensitive adhesive tape for protective covering which is hard to catch fire with a spark of welding, fusing or the like and does not generate a harmful gas by the thermal decomposition even when it catches fire and can be subjected to incineration treatment when it becomes unserviceable. SOLUTION: The flame-retardant pressure-sensitive adhesive tape for protective covering is obtained by further providing a pressure-sensitive adhesive layer containing a metal hydroxide as the flame-retardant on a synthetic resin film in a pressure-sensitive adhesive tape support which has been formed by laminating the synthetic resin film having a thickness of 0.004-0.050 nm on an aromatic polyamide base sheet having a thickness of 0.050-0.150 nm with an adhesive layer composed of a flame-retardant pressure-sensitive adhesive obtained by incorporating 10-150 pts.wt. flame-retardant into 100 pts.wt. acrylic adhesive, and has a total content of a halogen and phosphorus of <=50 ppm and an oxygen index of >=27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive tape used for temporary fixing, fixing, and joining of a curing sheet used in a site such as civil engineering or construction, and is exposed to sparks generated by welding or cutting. And a non-halogen, non-phosphorous flame-retardant pressure-sensitive adhesive tape which does not decompose when incinerated as waste to generate toxic gas.

[0002]

2. Description of the Related Art Curing sheets are used for building new construction, renovation,
It must be flame-retardant in dismantling, machine repairs, periodic inspections, etc., so that sparks or cigarettes generated when welding or cutting steel materials do not ignite the sheet and cause a fire. Therefore, a glass cloth or a PVC sheet whose surface is treated with silicone or PVC has been used. A similar flame-retardant function has also been required for a curing adhesive tape used for temporary fixing, fixing, joining, and the like of such a curing sheet.

Conventional flame-retardant curing adhesive tapes use a self-extinguishing PVC film or non-combustible glass cloth or other base material, or use paper, cloth, film, etc. other than the non-combustible base material. Sometimes, as an adhesive, an adhesive obtained by mixing a flame retardant such as halogen-containing flame retardant and antimony trioxide or a phosphorus-based flame retardant into a natural rubber or an acrylic resin-based adhesive is used. There was a limit to the amount of these additives in order to maintain the adhesive properties.

[0004] Due to the nature of the intended use, adhesive tapes for curing have been peeled off when they have completed their functions, discarded, incinerated or landfilled. However, adhesive tapes containing a substance such as halogen or antimony in the tape component have been used. In such a case, such a disposal method is not preferable for the environment, and special treatment must be performed.

[0005]

Among the above-mentioned flame-retardant pressure-sensitive adhesive tapes, a pressure-sensitive adhesive tape using a PVC film-based pressure-sensitive adhesive or a pressure-sensitive adhesive containing a halogen-containing flame-retardant is one of the sparks generated during the above-mentioned work. However, when it is dropped or mixed with an unnecessary sheet and discarded and burned, it has a disadvantage that toxic halogen gas such as chlorine or bromine is generated by thermal decomposition.

Further, the use of flame retardant aids such as antimony trioxide and glass cloth used as a base material may contain toxic arsenic as an impurity, so that the use of these materials is restricted. Disadvantages also existed.

[0007] An object of the present invention is to solve the above-mentioned disadvantage of being restricted in use, and it is difficult to ignite even if sparks or the like generated by welding or fusing fall on the tape.
Another object of the present invention is to provide an adhesive tape for curing that prevents fire spread without generating toxic gas due to thermal decomposition even when ignited, and that can also employ a normal incineration treatment or the like when disposing of an unnecessary adhesive tape.

[0008]

Means for Solving the Problems As a result of repeated studies to solve the above-mentioned problems in the conventional adhesive tape for curing, the present inventors have found that a base sheet made of aromatic polyamide paper or nonwoven fabric is obtained. A synthetic resin film is adhered using an adhesive to which a flame retardant such as at least one inorganic flame retardant is added, and an adhesive layer containing a flame retardant in the same manner as described above on the synthetic resin film surface The pressure-sensitive adhesive tape provided with sufficient adhesiveness and flame-retardant function required for the flame-retardant curing adhesive tape, and found that it has the property of being capable of disposal without environmental problems, The present invention has been completed. The present invention includes the following inventions.

(1) An acrylic adhesive 1 is placed on an aromatic polyamide base sheet having a thickness of 0.050 to 0.150 mm.
0.004 to 100 parts by weight of a flame-retardant adhesive compounded with 10 to 150 parts by weight of a flame retardant, and a thickness of 0.004 to
A pressure-sensitive adhesive layer containing a metal hydroxide as a flame retardant is further provided on the surface of the synthetic resin film of the pressure-sensitive adhesive tape support formed by laminating a 0.050 mm synthetic resin film. Content is 50p
pm or less and an oxygen index of 27 or more.

(2) The pressure-sensitive adhesive layer containing the metal hydroxide as a flame retardant comprises 50 to 140 parts by weight of the metal hydroxide and 10 to 100 parts by weight of nitrogen with respect to 100 parts by weight of the acrylic pressure-sensitive adhesive. The adhesive tape for flame-retardant curing according to (1), which is an adhesive layer containing an organic flame retardant.

(3) The pressure-sensitive adhesive tape for flame-retardant curing as described in (1) or (2), wherein the aromatic polyamide base material is an aromatic polyamide paper or nonwoven fabric. . (4) The adhesive layer of the flame-retardant pressure-sensitive adhesive containing the flame retardant is characterized in that it is a pressure-sensitive adhesive layer containing a metal hydroxide as a flame retardant, (1) to (3) The adhesive tape for flame-retardant curing according to any one of claims 1 to 7.

(5) The flame-retardant curing according to any one of (1) to (4), wherein the metal hydroxide is aluminum hydroxide and / or magnesium hydroxide. Adhesive tape. (6) The nitrogen-containing organic flame retardant is at least one selected from melamine, melamine derivatives, melamine cyanurate, guanidine compounds and melamine resins (1). Adhesive tape for flame retardant curing.

(7) The synthetic resin film according to any one of (1) to (6), wherein the synthetic resin film is a synthetic resin film selected from polyethylene, polypropylene, polyester, polycarbonate, nylon, polyimide and the like. The adhesive tape for flame retardant curing according to claim 1. (8) In the UL combustion test (UL94) standard, VTM-
0. The adhesive tape for flame-retardant curing according to any one of the items (1) to (7), wherein the pressure-sensitive adhesive tape conforms to 0.

(9) The average particle diameter of the metal hydroxide and the nitrogen-containing organic flame retardant is 0.6 to 25 μm, preferably 1 to 1 μm.
The flame-retardant pressure-sensitive adhesive tape according to any one of items (1) to (8), which has a thickness of 0 μm. (10) The adhesive layer comprising a flame-retardant adhesive containing the flame retardant is formed of the same adhesive as the adhesive layer containing the metal hydroxide as a flame retardant (1). The pressure-sensitive adhesive tape for flame-retardant curing according to any one of items (1) to (9).

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
As shown in FIG. 1, a flame-retardant curing adhesive tape of the present invention comprises a self-extinguishing aromatic polyamide paper or nonwoven fabric on a base sheet 1 made of a synthetic resin with a flame-retardant adhesive layer 2. It has a structure in which a film 3 is attached to form a pressure-sensitive adhesive tape support sheet, and a flame-retardant pressure-sensitive adhesive layer 4 is provided on the synthetic resin film surface of the support sheet. Here, the flame-retardant adhesive layer 2 and the flame-retardant pressure-sensitive adhesive layer 4 are flame-retarded by adding a metal hydroxide or a metal hydroxide, and preferably further a nitrogen-containing organic flame retardant, It has a structure in which a flame retardant is dispersed in both the adhesive layer and the adhesive layer.

The function of the adhesive tape for flame-retardant curing of the present invention is as follows. It does not break when stepped on or when a cart passes, and has adhesive strength to withstand the weather. In addition, when peeling after finishing its role, it is easy to peel again, and even if it is burned as waste, the total concentration of generation of toxic chlorine gas and phosphine gas such as chlorine and bromine by thermal decomposition is 50 ppm.
It is limited to the following traces.

Accordingly, as the base sheet in the support sheet of the pressure-sensitive adhesive tape of the present invention, a paper or nonwoven fabric made of aromatic polyamide having a self-extinguishing property and having a thickness of 0.050 to 0.150 mm is used. The thickness is 0.05
If the thickness is less than 0 mm, the resistance to cracking caused by stepping or the passage of a cart and the resistance to sparks such as welding are lowered, and if it is less than 0.150 mm, the durability is sufficient, but the curing work is insufficient. The tape cutting property at the time is deteriorated, and the price is disadvantageous. The thickness of the base sheet is
Preferably, it is in the range of 0.060 to 0.100 mm.

The synthetic resin film to be bonded to the paper or non-woven fabric made of aromatic polyamide has a thickness of 0.004 to 0.5.
Any film made of a high-molecular polymer containing no halogen and phosphorus in a range of 050 mm may be used. For example, a film made of a high-molecular material such as polyethylene, polypropylene, polyester, polycarbonate, acrylic, nylon, or polyimide Is mentioned. No toxic gas containing halogen, phosphorus or the like is generated by normal combustion. When the thickness of the synthetic resin film is less than 0.004 mm, problems such as wrinkles are liable to occur in a laminating operation in a manufacturing process, and when the thickness exceeds 0.050 mm, flame retardancy is exhibited. It is difficult, and the tape cut property is also worse. The thickness of the synthetic resin film is preferably 0.012 to 0.025 m
m.

The flame-retardant adhesive layer and the flame-retardant adhesive layer in the flame-retardant curing pressure-sensitive adhesive tape of the present invention may be a halogen-based or phosphorus-based flame-retardant which is environmentally harmful as described above, or a trioxide harmful to the human body. It is characterized by flame retardancy without using any flame retardant auxiliary such as antimony. As a flame retardant satisfying such requirements, a metal hydroxide or a nitrogen-containing organic flame retardant is used for the flame-retardant adhesive layer and the flame-retardant adhesive layer in the flame-retardant curing adhesive tape of the present invention. . Specific examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, calcium aluminate and the like. The flame retardant effects of metal hydroxides include the dilution of combustible gas by water vapor generated by heating, the formation of adiabatic barriers due to the formation of char, and the endothermic effect during the dehydration reaction, such as retardation and prevention of combustion. Play a major role in the effect.

On the other hand, specific examples of the nitrogen-containing organic flame retardant include melamine, melamine derivatives such as melamine cyanurate, guanidine compounds, and melamine resins. Among these, melamine resin powder and melamine cyanurate are particularly preferred from the viewpoints of dispersibility in an acrylic polymer as a pressure-sensitive adhesive, mixing properties, influence on adhesiveness, and the like. The average particle size of the flame retardants listed above is from 0.6 to 25.
μm, preferably 1 to 10 μm. When it is smaller than 0.6 μm, handling as powder becomes inconvenient,
If it exceeds μm, there are problems of stability after being dispersed in the pressure-sensitive adhesive and a problem that a sufficient adhesive strength may not be obtained as a pressure-sensitive adhesive tape.

As the metal hydroxide used in the present invention, a sufficient flame-retardant effect can be obtained by using aluminum hydroxide and magnesium hydroxide alone or in a mixture thereof. If necessary, a flame-retardant effect can be further improved by adding a nitrogen-containing organic flame retardant such as melamine cyanurate or melamine resin powder.

The pressure-sensitive adhesive used in the flame-retardant adhesive layer and the flame-retardant pressure-sensitive adhesive layer of the present invention can be obtained by dispersing and blending the above-mentioned flame retardant into an acrylic pressure-sensitive adhesive diluted with a solvent. The blending amount of the flame retardant is not particularly limited as long as the pressure-sensitive adhesive composition exhibits predetermined flame retardancy and adhesive strength, but is suitably in the range of 10 to 150 parts by weight based on 100 parts by weight of the acrylic base pressure-sensitive adhesive. The amount of the flame retardant in the pressure-sensitive adhesive is preferably 50 to 100 parts by weight from the viewpoint of achieving both sufficient flame retardancy and good adhesive strength. When the amount of the flame retardant exceeds 150 parts by weight, the oxygen index becomes 27 or more, but it causes a decrease in the adhesive property and a decrease in the cohesiveness of the adhesive layer, etc., resulting in insufficient fixing ability and peeling during re-peeling. However, there is a possibility that defects such as adhesive residue may occur, which is not preferable. On the other hand, if the amount is less than 10 parts by weight, the oxygen index becomes less than 27,
In some cases, the flame retardant properties in the UL combustion test (94 VTM-0) specifications may not be satisfied.

In the flame-retardant curing adhesive tape of the present invention, the same flame-retardant pressure-sensitive adhesive is used for both the flame-retardant adhesive layer and the flame-retardant pressure-sensitive adhesive layer in order to simplify the manufacturing operation. good. Of course, the composition of both adhesive compositions can be changed as needed. For example, in order to balance the adhesive strength of the flame-retardant adhesive layer, the cohesive force of the flame-retardant adhesive layer, the adhesive force, and the adhesion with the synthetic resin film, the flame retardant is mixed with the adhesive of the adhesive layer. The amount may be increased or decreased, and the blending amount of the flame retardant with respect to the pressure-sensitive adhesive of the pressure-sensitive adhesive layer may be reduced or increased.

In the pressure-sensitive adhesive tape for flame-retardant curing of the present invention, the surface of the aromatic polyamide paper or nonwoven fabric used as the base sheet is preferably subjected to a modification treatment such as a release treatment.

As described above, the pressure-sensitive adhesive tape for flame retardant curing of the present invention has an oxygen index of 27 or more. Because the support surface layer is made of aromatic polyamide paper or non-woven fabric having self-extinguishing properties, holes are easily opened, it does not easily ignite, even if holes are opened or ignited When the flame-retardant adhesive layer is immediately heated, the contained metal hydroxide causes an endothermic dehydration reaction, and the nitrogen-containing organic flame retardant generates an incombustible gas, thereby burning the entire combustion system. It exhibits a self-extinguishing function by making the atmosphere difficult.

Further, the flame-retardant curing adhesive tape of the present invention does not break even when people step on it or a cart goes through during the construction period, and has an adhesive strength that can withstand the weather.
In addition, when it becomes unnecessary, there is no tape breakage or adhesive residue from the adherend, and the adherend can be peeled off neatly.

[0027]

Next, the present invention will be described based on examples. In the examples and comparative examples, “parts” means “parts by weight”.

Example 1 80 parts of aluminum hydroxide (trade name: Heidilite H-32 manufactured by Showa Denko KK) was used for 100 parts of the solid content of an acrylic polymer composed of a copolymer of butyl acrylate and acrylic acid. The adhesive obtained by blending and dispersing well
After adding 3.5 parts of a polyisocyanate crosslinking agent and stirring,
One side of an aromatic polyamide paper (80 μm) is coated so that the thickness after drying becomes 25 μm, and then bonded to a polyester film (16 μm). The material was applied so that the thickness after drying was 30 μm, to obtain a flame-retardant curing adhesive tape of the present invention.

Example 2 60 parts of aluminum hydroxide (trade name: Heidilite H-32, manufactured by Showa Denko KK) per 100 parts of the solid content of an acrylic polymer composed of a copolymer of butyl acrylate and acrylic acid. , And 20 parts of magnesium hydroxide (trade name: Kisuma 5A, manufactured by Kyowa Chemical Industry Co., Ltd.), and after sufficiently dispersing the resulting adhesive, 3.5 parts of a polyisocyanate-based cross-linking agent was added thereto, followed by stirring. Group polyamide paper (80μ
m) is coated on one side so that the thickness after drying is 25 μm, bonded to a polyester film (16 μm), and then the same pressure-sensitive adhesive composition as above is further dried on the other side of the polyester film. Was applied to obtain a flame-retardant curing adhesive tape of the present invention.

Example 3 50 parts of aluminum hydroxide (trade name: Heidilite H-32 manufactured by Showa Denko KK) per 100 parts of solid content of an acrylic polymer composed of a copolymer of butyl acrylate and acrylic acid. And melamine resin powder (trade name: Eposter S12 manufactured by Nippon Shokubai Co., Ltd.) in an amount of 30 parts, and the resulting dispersion was sufficiently dispersed.
After adding 5 parts and stirring, it is coated on one side of an aromatic polyamide paper (80 μm) so that the thickness after drying becomes 25 μm, laminated on a polyester film (16 μm), and further on the opposite side of the polyester film. Apply the same pressure-sensitive adhesive composition as described above so that the thickness after drying is 30 μm,
The flame-retardant curing adhesive tape of the present invention was obtained.

Example 4 50 parts of aluminum hydroxide (trade name: Hygilite H-32, manufactured by Showa Denko KK) per 100 parts of a solid content of an acrylic polymer composed of a copolymer of butyl acrylate and acrylic acid. , Magnesium hydroxide (trade name: Kisuma 5)
A: 15 parts of Kyowa Chemical Industry Co., Ltd. and 15 parts of melamine resin powder (trade name: Eposter M30 manufactured by Nippon Shokubai Co., Ltd.)
After mixing and adding 3.5 parts of a polyisocyanate-based cross-linking agent and stirring, the thickness after drying on one side of an aromatic polyamide paper (80 μm) was 25 μm.
And a polyester film (16μ)
m), and then the same pressure-sensitive adhesive composition as above is dried on the opposite side of the polyester film to a thickness of 30 μm.
m to give a flame-retardant adhesive tape for curing according to the present invention.

Example 5 80 parts of aluminum hydroxide (trade name: Heidilite H-32 manufactured by Showa Denko KK) was used for 100 parts of the solid content of an acrylic polymer composed of a copolymer of butyl acrylate and acrylic acid. The adhesive obtained by blending and dispersing well
After adding 3.5 parts of a polyisocyanate crosslinking agent and stirring,
One side of an aromatic polyamide paper (80 μm) is coated so that the thickness after drying becomes 25 μm, and a nylon film (2
5 μm (trade name: Emblem, manufactured by Unitika), and then the same adhesive composition as described above was further applied to the opposite surface of the nylon film so that the thickness after drying was 30 μm. An adhesive tape for flammable curing was obtained.

Comparative Example 1 A bromine flame retardant [tetrabromo bisphenol A derivative, (trade name: Fireguard 3000 Teijin Chemicals) was used for 100 parts of the solid content of an acrylic polymer composed of a copolymer of butyl acrylate and acrylic acid. 40)
Parts and 20 parts of antimony trioxide were blended and sufficiently dispersed, and a pressure-sensitive adhesive obtained by mixing a polyisocyanate crosslinking agent with 3.5 parts was obtained.
After stirring, the mixture was applied to one side of an aromatic polyamide paper (80 μm) so that the thickness after drying was 25 μm, and bonded to a polyester film (16 μm). The same pressure-sensitive adhesive composition was applied so that the thickness after drying became 30 μm, to obtain a halogen-based flame-retardant pressure-sensitive adhesive tape for curing.

COMPARATIVE EXAMPLE 2 3.5 parts of a polyisocyanate crosslinking agent was blended with 100 parts of a solid content of an acrylic polymer composed of a copolymer of butyl acrylate and acrylic acid, and the resulting pressure-sensitive adhesive was stirred. One side of an aromatic polyamide paper (80 μm) is coated so that the thickness after drying becomes 25 μm, and is bonded to a polyester film (16 μm). Then, the same adhesive composition as described above is further applied to the other side of the polyester film. Was applied so that the thickness after drying was 30 μm to obtain an adhesive tape for general curing.

The properties of the flame-retardant curing adhesive tapes obtained in the examples and comparative examples were measured by the following methods. The results are shown in Table 1. [Oxygen index] Measured according to JIS K7021. [Combustion test] A judgment was made by conducting a combustion test according to the UL standard (UL94). [Halogen gas generation] Tubular electric furnace method JIS K2
According to 541, it was measured by an ion chromatography method.

[Phosphorus content] After acid decomposition, the content was measured by molybdenum blue (ascorbic acid reduction) absorption spectrophotometry. [Adhesive force] It was measured according to JIS Z 0237. [Removability] A sample prepared in accordance with JIS Z 0237 was subjected to an acceleration test at 65 ° C. × 80% RH × 72 hours, and after returning to room temperature, the tape was quickly peeled off to observe the remaining adhesive.

[0037]

[Table 1]

[0038]

As is evident from the results in Table 1, the flame-retardant curing adhesive tape of the present invention not only has excellent flame retardancy which sufficiently satisfies the flame retardancy criteria of the curing adhesive tape. The paper or nonwoven fabric made of aromatic polyamide constituting the flame-retardant curing adhesive tape, the synthetic resin film, the flame-retardant adhesive layer and the flame-retardant adhesive layer each substantially contain a halogen or a phosphorus-based compound. Therefore, there is no danger that toxic halogen gas or phosphine gas will be generated by thermal decomposition even if sparks or cigarette fires fall due to welding or melting, or even if incinerated after use.

[Brief description of the drawings]

FIG. 1 is a diagram showing a layer structure of a flame-retardant curing adhesive tape.

[Explanation of symbols]

 1: base sheet 2: flame-retardant adhesive layer 3: synthetic resin film 4: flame-retardant adhesive layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 21/02 C09K 21/02 21/10 21/10 21/14 21/14 F-term (Reference) 4F100 AA17C AH03B AH03C AK04A AK07A AK25B AK25C AK25G AK41A AK45A AK47A AK48A AK49A AK51 BA03 BA07 BA10A BA10C BA25 CA08 CB05B CB05C DG10A DG15A EC18 EC182 EH46 EH462 EJ05 GB07 GB90 JJ07 JL13B JL13C 4H028 AA10 AA12 AA29 AA30 AA42 AA44 AB04 4J004 AA10 AA18 AB01 CA04 CA06 CC03 FA04

Claims (8)

[Claims] An acrylic pressure-sensitive adhesive (10) is coated on an aromatic polyamide base sheet having a thickness of 0.050 to 0.150 mm.
0.004 to 0.004 parts by weight of an adhesive layer made of a flame-retardant adhesive containing 10 to 150 parts by weight of a flame retardant per 0 parts by weight
A pressure-sensitive adhesive layer containing a metal hydroxide as a flame retardant is further provided on the surface of the synthetic resin film of the pressure-sensitive adhesive tape support formed by laminating a 0.050 mm synthetic resin film. Content is 50p
pm or less and an oxygen index of 27 or more. 2. The pressure-sensitive adhesive layer containing the metal hydroxide as a flame retardant contains 50 to 140 parts by weight of a metal hydroxide and 10 to 100 parts by weight of nitrogen based on 100 parts by weight of an acrylic pressure-sensitive adhesive. The adhesive tape for flame-retardant curing according to claim 1, wherein the adhesive tape is an adhesive layer containing an organic flame retardant. 3. The aromatic polyamide substrate is an aromatic polyamide paper or nonwoven fabric,
The flame-retardant curing adhesive tape according to claim 1. 4. The adhesive layer made of a flame-retardant pressure-sensitive adhesive containing a flame-retardant is a pressure-sensitive adhesive layer containing a metal hydroxide as a flame-retardant. The adhesive tape for flame-retardant curing according to claim 1. 5. The method according to claim 1, wherein the metal hydroxide is aluminum hydroxide and / or magnesium hydroxide.
The flame-retardant adhesive tape for curing according to any one of claims 1 to 4. 6. The flame retardant according to claim 2, wherein the nitrogen-containing organic flame retardant is at least one selected from melamine, melamine derivatives, melamine cyanurate, guanidine compounds and melamine resins. Curing adhesive tape. 7. The synthetic resin film according to claim 1, wherein the synthetic resin film is a synthetic resin film selected from polyethylene, polypropylene, polyester, polycarbonate, nylon, polyimide and the like. Flame retardant adhesive tape for curing. 8. The method according to claim 1, wherein in the UL combustion test (UL94) standard, VTM-0 is satisfied.
The adhesive tape for flame-retardant curing according to any one of claims 1 to 7.