JPH09208906A - Flame-retardant adhesive film and flat cable using the same - Google Patents

Abstract

(57) [PROBLEMS] To provide a flame-retardant adhesive film which is excellent in adhesiveness and electrical insulation and has flame retardancy, and a flat cable using the same. An adhesive layer is formed on a substrate made of a thermoplastic polyester resin flame-retarded with a flame retardant.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a flame-retardant adhesive film and a flat cable using the same.

[0002]

2. Description of the Related Art Conventionally, in electric wire mounting technology, a flat cable in which a plurality of conductors having a flat cross section are covered in a sandwich shape with an electrically insulating resin from both sides has been widely used for efficient wiring work. Has been. Such a flat cable is disclosed, for example, in Japanese Patent Application Laid-Open No. 5-282922, and is lightweight and easy to install. Adoption is under consideration.

In recent years, since the use of flat cables has been studied for various purposes, flame retardancy has been required depending on the applications, and especially for electric equipment members, automobile applications, etc. The demand is remarkable. As a flame retarding method, for example, a method of adding a flame retardant to the adhesive layer has been studied, as disclosed in JP-A-5-303918. However, such a method has a problem that the adhesive strength of the adhesive layer is lowered by adding the flame retardant.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is a flame-retardant adhesive having excellent flame retardancy and excellent adhesiveness and electrical insulation. To provide a flexible film and a flat cable using the same.

[0005]

The flame-retardant adhesive film of the present invention is characterized in that an adhesive layer is formed on a substrate made of a thermoplastic polyester resin flame-retarded with a flame retardant. It is what

Examples of the thermoplastic polyester resin used as the substrate in the present invention include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyhexylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene-1,2-bis. (Phenoxyethane) -4,4'-
Polymers such as dicarboxylate; copolymers such as polyethylene isophthalate-terephthalate, polybutylene terephthalate-isophthalate and polybutylene terephthalate-decane dicarboxylate.

Among the above-mentioned thermoplastic polyester resins, polybutylene terephthalate (hereinafter referred to as PBT) is preferable from the viewpoints of processability, heat resistance and dimensional stability, and PBT may be used alone. It may be used in a composition with a system elastomer.

The above PBT is a thermoplastic polyester resin obtained by polycondensation containing 1,4-butanediol and terephthalic acid as main components. The above PBT has PB
A diol component other than 1,4-butanediol or a dicarboxylic acid component other than terephthalic acid may be used as a monomer component as long as the original properties of T are not impaired.

Examples of the diol component other than 1,4-butanediol include ethylene glycol, diethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol and the like. Further, as the dicarboxylic acid component other than the terephthalic acid, isophthalic acid,
Sebacic acid, adipic acid, azelaic acid, succinic acid, and the like.

The PBT has an intrinsic viscosity (I.
V. When the value of () is low, the resulting film is broken at the time of bending. Therefore, the intrinsic viscosity in o-chlorophenol at 25 ° C. is preferably at least 0.6 or more.

Examples of the polyester elastomers include polycondensates of polyester components and soft components such as polyether and polysiloxane components. Particularly, polyester and polyether polymers similar to those used for polyester resins are used. It is preferable to use a polyether-ester type elastomer which is a condensate.

When the blending ratio of the polyester-based elastomer used in the above composition is low, the resulting multilayer film lacks toughness, and when it is too high, the moldability is adversely affected and the layer is disturbed, so that 100 parts by weight of PBT is used. 10 to 300 parts by weight is preferable.

The halogen-based flame retardant used for making the above thermoplastic polyester resin flame-retardant preferably has a halogen content of 20% by weight or more.
Perchloropentacyclodecane, hexabromobenzene, pentabromotoluene, hexabromobiphenyl,
Low molecular bromine-containing compounds such as decabromobiphenyl, hexabromocyclodecane, decabromodiphenyl ether, octabromodiphenyl ether, hexabromodiphenyl ether, bis (pentabromophenoxy) ethane, ethylenebis- (tetrabromophthalimide), and tetrabromobisphenol A; Brominated polycarbonate, brominated epoxy compound, brominated phenoxy compound,
Examples include halogenated polymers and oligomers such as poly (brominated benzyl acrylate), brominated polyphenylene ether, brominated bisphenol A / chlorinated cyanurine / brominated phenol condensate, brominated polystyrene, and the like.
These may be used alone or in combination of two or more.

When the amount of the halogen-based flame retardant added is small, sufficient flame retardancy cannot be imparted, and when it is large, the physical properties of the base material are deteriorated. Therefore, the thermoplastic polyester resin 100 is used.
The amount is preferably 1 to 60 parts by weight, more preferably 5 to 30 parts by weight, based on parts by weight.

Antimony oxide may be used in combination with the halogen-based flame retardant as a flame retardant aid. Examples of antimony oxide include antimony trioxide and antimony pentoxide. The addition amount of the flame retardant aid is 1 to 30 with respect to 100 parts by weight of the thermoplastic polyester resin.
It is preferably part by weight, more preferably 3 to 20 parts by weight. In particular, it is preferable to add one antimony atom per 2 to 5 halogen atoms of the halogen-based flame retardant.

Glass fibers, inorganic fillers and the like may be added to the above thermoplastic polyester-based resin within a range that does not impair the physical properties thereof.

Further, the thermoplastic polyester resin includes
An antioxidant may be added in order to prevent the resin from burning during the molding process to improve the appearance of the molded body and to prevent the oxidation deterioration and the deterioration of the mechanical strength.

As the above antioxidant, 2,6-di-t is used.
-Butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5-di-t-butyl-4-
(Hydroxyphenyl) propionate, 2,2′-methylenebis (4-methyl-6-t-butylphenol),
2,2'-methylenebis (4-ethyl-6-t-butylphenol), 4,4'-thiobis (3-methyl-6-t-
Butylphenol), 4,4'-butylidenebis (3-methyl-6-t-butylphenol), tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4-hydroxyphenyl) propionate] methane, 1 Phenol compounds such as 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane; phenyl-β-
Amine compounds such as naphthylamine and N, N′-diphenyl-p-phenylenediamine; phosphorus compounds such as tris (nonylphenyl) phosphite, triphenylphosphite, trioctadecylphosphite, diphenylisodecylphosphite; dilauryl Examples thereof include sulfur compounds such as thiodipropionate, dimyristyl thiodipropionate and distearyl thiodipropionate. These antioxidants may be used alone,
Two or more kinds may be used in combination.

When the amount of the above-mentioned antioxidant added is small, a sufficient effect cannot be obtained, and even when it exceeds a certain amount, no further effect can be obtained. Therefore, it is based on 100 parts by weight of the thermoplastic polyester resin. It is preferably 2 parts by weight or less, and more preferably 0.1 to 1 part by weight.

If necessary, the thermoplastic polyester resin may further contain an ultraviolet absorber, an antistatic agent, a lubricant,
Release agents, pigments and the like may be added.

The flame-retardant adhesive film of the present invention includes
Using a single layer film of a thermoplastic polyester resin or a laminated film in which the single layer film is laminated in multiple layers as a base material,
An adhesive layer is formed on one side or both sides of the base material.

The adhesive forming the adhesive layer is as follows:
For example, an adhesive composed of a modified ethylene-vinyl acetate copolymer graphit-polymerized with an unsaturated carboxylic acid and an unmodified ethylene-ethyl acrylate copolymer; a polyester copolymer composed of a dicarboxylic acid component, a diol component and a triazine component. And an adhesive containing a polyisocyanate compound as a main component; an adhesive containing three components of a saturated copolymer polyester resin, a polyethylene resin, and an organic alkoxysilane.

The substrate may be treated with a primer for the purpose of improving the adhesive strength of the flame-retardant adhesive film. As such a primer, a chloroprene rubber / methyl methacrylate graft copolymer,
In addition to chlorinated polypropylene and cyclized rubber solution, isocyanate-based, polyester-based, urethane-based polymers and the like are used.

The flame-retardant adhesive film can be produced by various conventionally known methods. For example, it is possible to obtain a flame-retardant adhesive film by coating an adhesive with a bar coater or the like on a substrate formed by extruding a flame-retardant thermoplastic polyester resin from an extruder into a film shape. it can.

In the flame-retardant flat cable of the present invention, the pressure-sensitive adhesive layers of the flame-retardant adhesive film are opposed to each other, and a conductor having a wiring pattern is sandwiched between the both pressure-sensitive adhesive layers for lamination. It is obtained by doing.

The flame-retardant flat cable of the present invention may be used as a multi-layer structure in which conductors having a wiring pattern are three-dimensionally incorporated by laminating a plurality of flame-retardant flat cables. An aluminum foil may be laminated on the surface of the flame-retardant flat cable to provide electromagnetic wave shielding properties. For this purpose, as the base material of the flame-retardant flat cable, one having adhesive layers provided on both sides may be used, or by laminating the flame-retardant flat cables with another adhesive, Aluminum foil may be laminated.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

[Preparation of Resin Composition for Base Material (A)] 25 ° C.
Intrinsic Viscosity (I.
V. ) An antioxidant (“IRGAN” manufactured by Ciba-Geigy Co., Ltd.) is used with respect to 100 parts by weight of 1.0 polybutylene terephthalate.
OX B-225 ″) (0.1 parts by weight) was melt-kneaded to prepare a resin composition for the base material (A).

[Preparation of Resin Composition for Base Material (B)] 25 ° C.
Intrinsic Viscosity (I.
V. ) An antioxidant (“IRGAN” manufactured by Ciba-Geigy Co., Ltd.) is used with respect to 100 parts by weight of 1.0 polybutylene terephthalate.
OX B-225 ") 0.1 part by weight, and the amount of the halogen-based flame retardant shown in Table 1 [Perchloropentacyclodecane (" Dechlorane Plus "manufactured by Occidental Chemical Co., Ltd.)
Alternatively, decabromodiphenyl ether (manufactured by Asahi Glass Co., Ltd.)] and antimony trioxide were melt-kneaded to prepare a flame-retarded resin composition for the base material (B).

[Preparation of Adhesive (C-1)] An ethylene-vinyl acetate copolymer having a vinyl acetate content of 29% by weight and an MI (melt index) = 15, and a modified ethylene obtained by acryl-modifying the copolymer. Adhesive (C-1) was prepared by mixing with a vinyl acetate copolymer. The content of unmodified ethylene-vinyl acetate copolymer was 60% by weight.

[Preparation of Adhesive (C-2)] 4 mol of a 1: 1 (molar ratio) mixture of terephthalic acid and isophthalic acid,
2 mol ethylene glycol, 3.5 mol neopentyl glycol and 0.7 m cyclohexanedimethanol
100 parts by weight of polyester obtained by reacting ol with 5 parts by weight of hexamethylene diisocyanate were mixed to prepare an adhesive (C-2).

[Preparation of Adhesive (C-3)] 45 mol of dimethyl terephthalic acid and 100 m of 1,4-butanediol
saturated polyester (MI =
60, weight average molecular weight 100,000) 100 parts by weight, low-density polyethylene (MI = 9.5) 2 parts by weight, and γ-glycidoxypropyltrimethoxysilane 2 parts by weight by heat mixing to produce an adhesive (C-3). Was prepared.

[Preparation of Adhesive (C-4)] 100 parts by weight of the above adhesive (C-1), 20 parts by weight of perchloropentacyclodecane and 15 parts by weight of antimony trioxide are mixed to prepare an adhesive (C- 4) was prepared.

(Examples 1 to 4, Comparative Examples 1 and 2) The resin composition for a base material shown in Table 1 was extruded into a film and molded into 10
After producing a base material having a thickness of 0 μm, the adhesive shown in Table 1 was applied onto the base material by a bar coater to produce an adhesive film having an adhesive layer having a thickness of 50 μm. Then, the two adhesive layers of the adhesive film are made to face each other, a conductor having a wiring pattern is sandwiched between both adhesive layers, and then laminated by heat fusion using a laminating roll. A flat cable in which a conductor was sandwiched between the adhesive layers was produced. The used conductors and laminating conditions are as follows. Conductor: A copper foil having a thickness of 0.12 mm and a width of 3 mm was placed at 1 mm intervals. Laminating conditions: temperature 170 ° C., pressure 6 kg / cm ² ,
Speed 0.5m / min

The following performance evaluations were performed on the adhesive films and flat cables obtained in the above Examples and Comparative Examples, and the results are shown in Table 1. (1) Adhesive strength test Adhesive layers of an adhesive film are adhered to each other, and JIS Z-
In accordance with 1526, a 10 mm wide sample is pulled at a pulling speed of 2
The adhesive strength between the adhesive layers was measured by a T-type peel test at 00 mm / min at 90 ° C., and the adhesive strength of 1 kg / 10 mm or more was evaluated as ◯, and the adhesive strength of less than that was evaluated as x.

(2) Flammability test When an adhesive film having a width of 60 mm and a length of 150 mm was used as a sample, the sample was attached to a U-shaped holder, horizontally installed and ignited in the air, within 20 seconds. Those that self-extinguished were judged as ◯, and those that did not self-extinguish within 20 seconds were judged as x.

(3) Electrical Characteristics (Electrical Resistance, Withstanding Voltage) Test A flat cable was cut out so as to be slightly longer than 100 mm, and then the conductor portions at both ends were exposed, and the length of the unexposed portion was 100 mm. A sample was prepared. With respect to this sample, a voltage was applied to conductor portions located on opposite sides of each other, and the electric resistance between adjacent conductors was measured. Further, a withstand voltage test of 1 kV × 1 min was performed in the same manner. In the above test, the electric resistance between conductors was 10 ³ M
も の or more and no electrical conductivity failure after withstand voltage test
Those which were not so were judged as x.

(4) Folding resistance test After the flat cable was completely bent at 180 degrees and heated at 100 ° C. for 120 hours, one having no conductivity defect was marked with ◯, and one having conductivity defect was marked with x. , Judged.

[0039]

[Table 1]

[0040]

EFFECTS OF THE INVENTION The flame-retardant adhesive film of the present invention has excellent flame retardancy as well as excellent adhesiveness and electrical insulation by the above-mentioned constitution. The cable is suitably used for a wide range of applications such as automobiles and homes.

Claims (4)

[Claims] 1. A flame-retardant adhesive film comprising an adhesive layer formed on a base material made of a thermoplastic polyester resin flame-retarded with a flame retardant. 2. A flame-retardant adhesive film, wherein the thermoplastic polyester resin according to claim 1 is formed of polybutylene terephthalate alone or a composition of polybutylene terephthalate and a polyester elastomer. 3. A flame-retardant adhesive film, wherein the substrate according to claim 1 is formed of a thermoplastic polyester resin flame-retarded with a halogen-based flame retardant. 4. A conductor in which the pressure-sensitive adhesive layers of the flame-retardant adhesive film according to claim 1, 2 or 3 are laminated so as to face each other, and a wiring pattern is formed between both pressure-sensitive adhesive layers. A flat cable characterized by being sandwiched between.