JPH08143846A - Flame retardant adhesive - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a flame-retardant adhesive that can be used for bonding various articles such as flexible printed wiring boards and flat cables. [Structure] A flame-retardant composition comprising a thermoplastic high molecular weight polyester as a main component, and 20 to 100 parts by weight of a tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer based on 100 parts by weight of the polyester. An adhesive having excellent heat resistance and heat resistance is obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to improvements in flame retardant adhesives.

[0002]

2. Description of the Related Art In recent years, electronic devices have been required to be compact, lightweight and space-saving. In response to such requests,
Electronic devices include flexible printed wiring boards, flat cables, etc. that are lightweight, compact, and can be bent. Then, for example, in a flexible printed wiring board, an adhesive is often used such that a printed circuit is adhered to the insulating film by the adhesive.

Heat resistance and flame retardancy are often essential for adhesives used in such applications. For example, a saturated copolyester resin is used as a main component, and a brominated organic flame retardant and an inorganic flame retardant are used. It has been proposed to add a filler and dissolve these components in an organic solvent (JP-A-62-9).
6580).

Brominated organic flame retardants in this adhesive include decabromodiphenyl oxide, hexabromobenzene, tris (2,3-dibromopropyl) isocyanurate, and 2,2-bis (4-hydroxy-3,5-dibromo). Phenyl) propane or 2,2-bis (4-
Hydroxyethoxy-3,5-dibromophenyl) propane and the like are used. Further, as the inorganic filler, antimony trioxide, calcium carbonate, aluminum silicate, calcium fluoride, aluminum hydroxide, silicon dioxide,
Titanium oxide or the like is used.

[0005]

By the way, there is a strict demand for improving the performance of electronic devices, and therefore the adhesives used in the devices are also required to have improved properties. It is an object of the present invention to provide an adhesive (adhesive that is less likely to undergo thermal deterioration) that maintains flame retardancy and has improved heat resistance.

[0006]

Means for Solving the Problems As a result of intensive research to meet the above-mentioned demands, the present inventor has found that a thermoplastic high molecular weight polyester as a flame retardant is completely different from conventional tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride ternary The inventors have found that the heat resistance can be improved while maintaining the flame retardancy by adding a predetermined amount of a copolymer (hereinafter referred to as “THV”), and have completed the present invention.

That is, the flame-retardant adhesive according to the present invention contains THV based on 100 parts by weight of the thermoplastic high molecular weight polyester.
It is composed of 20 to 100 parts by weight.

The thermoplastic high molecular weight polyester used in the present invention is a linear saturated polyester obtained by polycondensation of dicarboxylic acid and diol, and its molecular weight is usually about 10,000 to 30,000. The above-mentioned dicarboxylic acid is an aromatic dicarboxylic acid such as terephthalic acid or isophthalic acid, or an aliphatic dicarboxylic acid such as adipic acid or sebacic acid, and the diol is ethylene glycol, 1,
4-Butanediol, diethylene glycol, neopentyl glycol and the like can be used.

Such thermoplastic high molecular weight polyesters are already commercially available, for example, under the trade names of Byron 30P, Byron 900, Byron 990 from Sumitomo Chemical Co., Ltd., and VC-40, VC-60 by Sumitomo Chemical Co., Ltd. Therefore, these can be obtained and used.

In the present invention, THV is 20 to 100 relative to 100 parts by weight of the thermoplastic high molecular weight polyester.
It is compounded in parts by weight. THV is tetrafluoroethylene,
It is a terpolymer of hexafluoropropylene and binindene fluoride. THV is a flame retardant additive,
If the blending amount is less than 20 parts by weight, flame retardancy is insufficient, and if the blending amount is more than 100 parts by weight, the adhesiveness is deteriorated, which is not preferable. This THV is
For example, 200G, 400 from Sumitomo 3M Limited
It is marketed under the trade name of G, 500G, etc.

In the present invention, if desired, calcium carbonate, aluminum silicate, calcium fluoride, silicon dioxide, aluminum oxide, aluminum hydroxide,
Inorganic fillers such as antimony trioxide, magnesium oxide, aluminum oxide, titanium oxide and silica, stabilizers (copper,
Additives such as iron, etc.), antioxidants, antioxidants, colorants and the like can also be added in appropriate amounts.

The flame-retardant adhesive according to the present invention can be used as a powder or pellet in which thermoplastic high molecular weight polyester and THV are mixed, and can also be used as a film containing these components.

[0013]

The present invention will be described in more detail with reference to the following examples.

Example 1 Using terephthalic acid and sebacic acid as dicarboxylic acids, ethylene glycol and neopentyl glycol as diols, and polycondensation thereof, a molecular weight of 3 was obtained.
0000 thermoplastic high molecular weight polyester (manufactured by Toyobo Co., Ltd., trade name Byron 990) is prepared.

20 parts by weight of THV (manufactured by Sumitomo 3M Co., Ltd., trade name G200) and an antioxidant (manufactured by Ciba Geigy Co., Ltd., trade name Irganox 1) per 100 parts by weight of the thermoplastic high molecular weight polyester.
010) Mix 2 parts by weight uniformly. Next, this mixture was extruded at a temperature of 180 ° C. into a film (thickness: 60 μm) to obtain a flame-retardant adhesive (Sample 1).

Example 2 The same operation as in Example 1 was conducted except that the blending amounts (parts by weight) of the thermoplastic high molecular weight polyester, THV and the antioxidant were set as shown in Table 1, and two types (Sample 2 and Sample 2) were used. 3)
A film-shaped flame-retardant adhesive of was obtained.

In Table 1, thermoplastic high molecular weight polyester, which is a blending component, is "A", THV is "B",
The antiaging agent was designated as "C".

Test Example The film-shaped flame-retardant adhesive obtained in Examples 1 and 2 above is laminated on one side of a polyethylene terephthalate film having a thickness of 50 μm at a temperature of 80 ° C. to obtain a film with an adhesive layer.

Next, this film with an adhesive layer is laminated on one surface of a copper foil (thickness: 100 μm) and bonded through a pair of pressure rolls (hereinafter, the film with an adhesive layer and the copper foil are bonded together). Is called "bonded body"). In the pressure bonding, the surface temperature of the roll was adjusted to 160 ° C. and the linear pressure was adjusted to 20 kg / cm ² .

Then, the normal adhesive strength of this adhesive and 1
The adhesive strength after heat deterioration at 35 ° C. for 7 days is IPCFC2.
Table 1 shows the results measured by the method specified in the 40-A standard. The unit of the adhesive force is "kg / 1 cm width".
In addition, Table 1 also shows the results of measuring the flame retardancy of this adhesive by the method specified in UL94.

[0021]

[Table 1]

Comparative Example 1 Two kinds of film adhesives were prepared in the same manner as in Example 1 except that the blending amounts (parts by weight) of the thermoplastic high molecular weight polyester, THV and the antioxidant were as shown in Table 2. (Samples 4 and 5) were obtained. Table 2 shows the results obtained by testing these film adhesives in the same manner as in the examples.

[0023]

[Table 2]

Comparative Example 2 100 parts by weight of a thermoplastic high molecular weight polyester (the same as used in Example 1), 50 parts by weight of decabromodiphenyl oxide, 25 parts by weight of antimony trioxide and an antioxidant (Irganox). 1010) 2 parts by weight was dissolved in 200 parts by weight of toluene to obtain a solution-form flame-retardant adhesive.

This flame-retardant adhesive was applied to one side of a polyethylene terephthalate film having a thickness of 50 μm,
It heated at 5 degreeC for 5 minutes, and obtained the film with an adhesive layer. When this was tested in the same manner as in the example, the normal adhesive strength was 2.3.
4kg / 1cm width, adhesive strength after deterioration is 1.37kg / 1c
The m width and flame retardancy were VTM0.

[0026]

INDUSTRIAL APPLICABILITY Since THV is blended with the thermoplastic high molecular weight polyester as described above, it has excellent flame retardancy and heat resistance and is useful for bonding various articles.

Claims (2)

[Claims] 1. Tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride terpolymer 20 to 100 parts by weight of a thermoplastic high molecular weight polyester.
A flame-retardant adhesive composed of 100 parts by weight. 2. The flame-retardant adhesive according to claim 1, which is in the form of a film.