JPH05140358A - Production of thermoplastic resin film coated with thermosetting resin - Google Patents

Abstract

PURPOSE:To obtain the subject film excellent in heat resistance, chemical resistance and flexibility by grinding a thermosetting resin composition having fluidity in a molten state followed by scattering the resultant powder on a base film, and then executing a heat treatment to convert said powder to a filmy product. CONSTITUTION:A dry blend comprising a copolyester resin made from terephthalic acid, ethylene glycol and neopentyl glycol, an epsilon-caprolactam-blocked isocyanate, a curing promoter, and a spreading agent is kneaded in a molten state to produce a thermosetting resin composition, which is, in turn, ground into powder. The powder is then uniformly scattered onto a thermoplastic resin film. The resultant film is heat-treated at a temperature not lower than the temperature at which the above composition becomes fluid and settable, but lower than the melting temperature of the above film to convert the powder to a filmy product, thus obtaining the objective film suitable as an electrical insulating film such as for capacitors or motors, or for flexible printed boards.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermoplastic film coated with a thermosetting resin having excellent heat resistance, chemical resistance and flexibility.

[0002]

2. Description of the Related Art Conventionally, in the field of insulating films for motors and flexible printed circuit boards where heat resistance and chemical resistance are required, heat resistance of thermoplastic resin films such as polyester and polyamide for general clothing and industrial materials The chemical resistance was not sufficient, and the usage conditions were limited. Further, high heat resistant resins such as polyetheretherketone and polyimide have problems such as high cost and poor film formability.

Crosslinking resins such as thermosetting resins are generally inexpensive and have good heat resistance and chemical resistance, but since they cure when heated, it is difficult to form a film by melt extrusion. It is known that a resin is dissolved, the solution is cast, the solvent is removed, and then heat treatment or the like is performed to obtain a crosslinked film (JP-A-63-218757).

However, in the conventional film manufacturing method as described above, since the resin must be dissolved, the solvent is removed, and the heat treatment is required, the process is complicated and the recovery of the organic solvent is also indispensable. In addition, the film of the cross-linking resin generally has poor flexibility and is fragile.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks, can be economically carried out without using any organic solvent, and is thermosetting which is more flexible than the crosslinkable resin film. The present invention provides a method for producing a thermoplastic resin film coated with a hydrophilic resin.

[0006]

Under the circumstances, the inventors of the present invention have conducted earnest studies on a thermoplastic resin film coated with a thermosetting resin which does not cause the above problems, and as a result, the present invention Reached That is, the gist of the present invention is as follows.

A thermosetting resin composition having a melt fluidity is pulverized into a powder, and the powder is uniformly dispersed on a thermoplastic resin substrate film, and then the thermosetting resin composition is melted and fluidized,
A heat treatment is performed at a temperature substantially higher than the temperature at which the curing reaction is possible and at a temperature lower than the melting temperature of the thermoplastic resin substrate film, so that only the thermosetting resin composition on the film surface is melted and fluidized and crosslinked to form a film. A method for producing a thermoplastic resin film coated with a thermosetting resin, wherein the thermosetting resin composition is a polyester resin composition, and the thermoplastic resin substrate film is a polyester film. The present invention relates to a method for producing a thermoplastic resin film coated with a thermosetting resin.

In the present invention, as the combination of the thermosetting resin composition and the thermoplastic resin substrate film, for example, as the thermosetting resin composition, epoxy resin, polyester resin, acrylic resin or the like, a curing agent or a curing catalyst, A blend of a leveling agent, other additives, etc., and a thermoplastic resin substrate film such as polyethylene, polypropylene, polyester,
Although there are films of nylon and the like, a combination of a polyester-based thermosetting resin composition and a polyester-based film is preferable in consideration of cost, flexibility, smoothness, adhesion, and the like.

That is, the composition of the polyester resin in the thermosetting resin composition is mainly composed of an aromatic dicarboxylic acid such as terephthalic acid or isophthalic acid as a dicarboxylic acid component and ethylene glycol as a diol component.
It is preferable to mainly use aliphatic diols such as neopentyl glycol, and aliphatic dicarboxylic acids such as adipic acid and azelaic acid, trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid, trimethylolethane, Those containing a small amount of trihydric or higher alcohol such as trimethylolpropane and pentaerythritol are more preferable because the melt fluidity and the crosslinking reactivity are improved.

The average degree of polymerization of the polyester resin is 5
The thing of the range of -50 is preferable. If it is lower than this, the strength of the coating film is not sufficient, and if it is higher than this, it becomes difficult to grind. Next, as the curing agent, when the terminal group of polyester is -OH type, there are an isocyanate compound and a melamine resin, for example, ε-caprolactam block isocyanate and methylated melamine. Examples of the terminal group of -COOH type include epoxy resin and triglycidyl isocyanurate.

When the resin to be used is an epoxy resin, a glycidyl ether type epoxy resin of bisphenol A to which dicyandiamide, phthalic anhydride or the like is added as a curing agent has a good melt fluidity and has a start temperature of the melt fluidization. It is a sharp, so it is preferable.

As the polyester film, a film made of biaxially stretched polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, etc. is used for strength, elongation and dimensional stability. It is preferable in terms.

The crushing of the thermosetting resin composition is preferably 50 mesh or less, more preferably 145 mesh or less. If it is larger than this, the surface of the coating film becomes rough and the smoothness is impaired. For the pulverization, it is preferable to pulverize the thermosetting resin composition that has been sufficiently cooled and solidified with a ball mill in order to obtain a uniform powder.

Next, the thermosetting resin composition may be sprayed onto the thermoplastic resin substrate film because the pulverized powder of the thermosetting resin composition may be evenly dispersed onto the thermoplastic resin substrate film. However, more preferably, the powder of the crushed thermosetting resin composition is charged with static electricity, and this is sprayed on the thermoplastic resin substrate film placed on the metal plate, and the powder is heated by the action of static electricity. The method of adhering to the surface of the plastic resin substrate film can be carried out easily and uniformly. Moreover, since the adhesion is due to static electricity, the thermosetting resin composition powder can be adhered to the thermoplastic resin substrate film having an arbitrary shape in an arbitrary thickness. Further, the film thickness of the thermosetting resin coating layer can be easily controlled by adjusting the amount of the thermosetting resin composition dispersed on the thermoplastic resin base film.

The heat treatment is carried out in a constant temperature oven,
It is necessary that the thermosetting resin composition is melted and fluidized, and the temperature is substantially higher than the temperature at which the curing reaction is possible and is lower than the melting temperature of the thermoplastic resin substrate film. It should be noted that the coating with the thermosetting resin may be made on both sides or one side of the thermoplastic resin substrate film, and can be freely selected according to the need for heat resistance and chemical resistance.

In the present invention, the thermosetting resin composition is made into a powder form so that the thermosetting resin composition is evenly dispersed on the thermoplastic resin substrate film, and the uncured heat is applied by heat treatment. The thermosetting resin is coated on the thermoplastic resin base film by melting and flowing the curable resin composition and advancing the curing reaction. The heat resistance and chemical resistance are mainly obtained by coating the thermosetting resin, while the flexibility, strength and elongation are mainly obtained by the thermoplastic resin base film.

[0017]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited thereto. In addition,
The methods for measuring the physical property values in the examples are as follows. Breaking strength, breaking elongation Tensilon UTM-4-100 manufactured by Toyo Baldwin Co., Ltd.
Using a mold, a 1 cm × 10 cm film piece was subjected to a tensile test at a speed of 10 cm / min. Heat Shrinkage The shrinkage of the film after standing for 10 minutes in a hot air dryer at 200 ° C. was measured. The flexible film was bent to see if it broke. Those that did not break were rated as ◯. Smoothness The smoothness of the film surface was visually evaluated. The smooth one was evaluated as ◯, and the slightly rough one was evaluated as Δ. The alkali resistant film was tested by immersing it in a 50% aqueous sodium hydroxide solution at 80 ° C. for 60 minutes. The one that did not change was evaluated as ◯, and the one that swelled was evaluated as Δ.

Example 1 An average degree of polymerization of 25 and a terminal hydroxyl value of 535 geq / 10 ⁶
87 parts by weight of a copolymerized polyester resin consisting of terephthalic acid as a dicarboxylic acid component and ethylene glycol 40 mol% neopentyl glycol 60 mol% as a diol component, 13 parts by weight of ε-caprolactam block isocyanate, and a curing accelerator (octyl tin). Maleate)
0.3 parts by weight, leveling agent (Acronal 4F manufactured by BASF)
After 1.0 part by weight was dry blended with a Henschel mixer (FM20B type manufactured by Mitsui Miike Seisakusho), the mixture was melt-kneaded at 100 ° C. using a co-kneader (PR-46 type manufactured by Buss Co.), cooled and solidified in a ball mill. It was crushed and separated by a wire mesh of 145 mesh to obtain a powder. Using a static electricity coating machine for coating this powder, a polyethylene terephthalate biaxially stretched film (thickness: 75 μm) fixed on a steel plate had a thermosetting resin coating layer thickness of 50 μm. Was sprayed. This film was heat-treated with a steel plate at 190 ° C. for 20 minutes in a hot air dryer. Next, after cooling this film to room temperature in air, remove the film from the steel plate,
The other surface was coated with a thermosetting resin in the same manner. The physical properties of the obtained film are shown in Table 1.

Example 2 Example 2 was repeated except that the thickness of the thermosetting resin coating was changed to 25 μm. The physical properties of the obtained film are shown in Table 1.

Example 3 The procedure of Example 1 was repeated, except that the powder of the thermosetting resin composition was separated with a wire mesh of 50 mesh. The physical properties of the obtained film are shown in Table 1.

Example 4 Solid epoxy resin (Araldite GT manufactured by Ciba-Geigy)
7004) 60 parts by weight, curing agent (dicyandiamide) 3
Parts by weight, curing accelerator (Chiragaigi Araldite D
A film was obtained in the same manner as in Example 1 by using 0.3 part by weight of Y-061) and 1.0 part by weight of a leveling agent (Araldite DY-022 manufactured by Ciba-Geigy). The physical properties of the obtained film are shown in Table 1.

Example 5 As a film for adsorbing a powder of a thermosetting resin composition, a film having a hemispherical surface irregularity (an unstretched polyethylene terephthalate film having a thickness of 100 μm has an irregular hemispherical diameter of about 1). 0.5 cm), an aluminum foil was attached to the back of the film as a metal plate for electrostatic adhesion according to the shape, and the thermosetting resin was coated in the same manner as in Example 1. Good for film with uneven surface
The film obtained was good in flexibility and alkali resistance.

[0023]

[Table 1]

[0024]

The thermoplastic resin film coated with the thermosetting resin according to the present invention is excellent in heat resistance, chemical resistance and flexibility, so that it can be used for insulation for capacitors and motors. It can be used for a film, a flexible printed circuit board, an industrial heat-resistant and fusion-proof film, a tobacco fusion-proof slit yarn, and the like.

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Claims (3)

[Claims] 1. A thermosetting resin composition having melt flowability is pulverized into a powder, and the powder is uniformly dispersed on a thermoplastic resin substrate film, and then the thermosetting resin composition is melted and fluidized,
A heat treatment is performed at a temperature substantially higher than the temperature at which the curing reaction is possible and at a temperature lower than the melting temperature of the thermoplastic resin substrate film, so that only the thermosetting resin composition on the film surface is melted and fluidized and crosslinked to form a film. A method for producing a thermoplastic resin film coated with a characteristic thermosetting resin. 2. A method for producing a thermoplastic resin film coated with a thermosetting resin according to claim 1, wherein the thermosetting resin composition is a polyester resin composition. 3. The thermosetting resin according to claim 1, wherein the thermoplastic resin substrate film is a polyester film.
For producing a coated thermoplastic resin film.