JP2002086616A - Glass fiber composite sheet and pressure-sensitive adhesive tape using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass fiber composite sheet enhanced in the durability as a whole by reducing the mutual friction of glass fibers, and a pressure- sensitive adhesive tape using the same. SOLUTION: In the glass fiber composite sheet constituted by coating a sheetlike article formed of glass fibers with a polytetrafluoroethylene resin 3, a heat-resistant lubricant is interposed between glass fibers of at least the sheetlike article.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass fiber composite sheet in which a sheet made of glass fiber is coated with a polytetrafluoroethylene resin, and an adhesive tape using the same.

[0002]

2. Description of the Related Art A glass fiber composite sheet in which a glass cloth or the like formed of glass fibers is coated with a polytetrafluoroethylene resin (hereinafter referred to as PTFE) has a heat resistance, an electrical insulation property, a release property, a dimensional stability, and the like. Since it has many excellent properties such as slidability, it has been used in a wider range of applications than before. For example, it is used for heat sealing of bag making and packaging lines, for covering guide parts, shooters, hoppers and the like which require releasability, or for heat-resistant insulation protection. At that time, it is often used as an adhesive tape using a glass fiber composite sheet having excellent mechanical properties as a tape base material. Further, the glass fiber composite sheet or the adhesive tape may be cut by hand without using scissors or the like.

As a method for producing the above-mentioned glass fiber composite sheet, there is a method in which an emulsion-polymerized PTFE dispersion is dipped in a glass cloth or the like, dried, and heated in an oven at a temperature equal to or higher than the melting point and sintered. Also, PT
There is also known a method in which FE molding powder is compression-molded and sintered or cut, or a PTFE film formed into a sheet by a casting method is laminated with a hot roll from both sides of a glass cloth or the like. The pressure-sensitive adhesive tape is produced by subjecting the sheet-like tape base material thus obtained to a single-sided adhesion treatment as required, and applying a pressure-sensitive adhesive to the adhesion-treated surface.

[0004]

When the pressure-sensitive adhesive tape or the like thus obtained is used, for example, for heat sealing, its life is often caused by breakage of the glass cloth. Destruction of the glass cloth occurs because glass fibers constituting the glass cloth break, but it is considered that the glass cloth is caused by abrasion due to rubbing of the fibers and repeated local bending force or tension. The breakage of the glass cloth also causes a break in the PTFE layer, and in heat seal applications, poor heat seal adhesion occurs due to a decrease in releasability. The problem of the durability of such a glass fiber composite sheet is not limited to heat seal applications, but is a common problem in applications requiring release properties, slidability, and the like.

Accordingly, an object of the present invention is to provide a glass fiber composite sheet in which the overall durability is improved by reducing friction between glass fibers, and an adhesive tape using the same.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and found that a heat-resistant lubricant was contained between glass fibers of a glass fiber composite sheet.
The inventors have found that the above object can be achieved, and have completed the present invention.

That is, the glass fiber composite sheet of the present invention comprises:
In a glass fiber composite sheet in which a sheet made of glass fiber is coated with a polytetrafluoroethylene resin, at least the sheet contains a heat-resistant lubricant between glass fibers.

In the above, the sheet-like material containing the heat-resistant lubricant is coated with a mixture layer of a polytetrafluoroethylene resin and the heat-resistant lubricant, and the mixture layer is coated with a polytetrafluoroethylene resin. Is preferred.

Preferably, the heat-resistant lubricant is a silicone oil.

On the other hand, the pressure-sensitive adhesive tape of the present invention uses any one of the glass fiber composite sheets described above as a tape base material.

[Effects] According to the glass fiber composite sheet of the present invention, since a heat-resistant lubricant is contained between the glass fibers, the friction between the glass fibers is reduced as shown in the results of the examples. It is possible to alleviate wear due to friction, local bending force or tension, and to improve the durability of the entire sheet.

Further, when the sheet-like material containing the heat-resistant lubricant is coated with the above-mentioned mixture layer and the mixture layer is coated with a polytetrafluoroethylene resin, the heat-resistant lubricant is contained. Since the mixture layer binds the glass fiber, the binding force is reduced by the heat-resistant lubricant, and the adhesion of the PTFE layer can be further increased by the interposition of the mixture layer. For this reason, a glass fiber composite sheet having higher durability can be obtained.

When the heat-resistant lubricant is a silicone oil, the silicone oil is excellent in heat resistance and lubricity and has good affinity with glass fibers. Friction between them can be effectively reduced.

On the other hand, according to the pressure-sensitive adhesive tape of the present invention, since the glass fiber composite sheet described in any of the above is used as a tape base material, the friction between glass fibers is reduced to improve the overall durability. Can be.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are cross-sectional views schematically showing examples of the pressure-sensitive adhesive tape of the present invention.

The pressure-sensitive adhesive tape of the present invention comprises, for example, as shown in FIG.
It has a structure in which a pressure-sensitive adhesive layer 5 is provided on the adhesive treatment layer 4.
As the glass fiber composite sheet S of the present invention, as shown in FIG.
Examples include those having a structure in which the TFE layer 3 is laminated, and those having a structure in which the PTFE layer 3 is laminated on both sides of the glass fiber sheet layer 1 without interposing the mixture layer 2 as shown in FIG.

The present invention relates to a glass fiber composite sheet S in which a glass fiber sheet layer 1 which is a sheet-like material formed of glass fibers is coated with a polytetrafluoroethylene resin. It is characterized by containing a heat-resistant lubricant. Therefore, an intermediate layer such as the mixture layer 2 or another adhesion improving layer may be interposed between the glass fiber sheet layer 1 and the PTFE layer 3. However, for the above-mentioned reason, the one in which the mixture layer 2 is interposed is particularly preferable.

The glass fiber sheet layer 1 is a layer in which a heat-resistant lubricant is added to a sheet-like material formed of glass fibers, and may contain PTFE together with the heat-resistant lubricant as described later. . As the sheet-like material, a woven fabric (glass cloth) or nonwoven fabric made of glass fiber can be used, but a woven fabric is preferable from the viewpoint of durability and dimensional stability. There are various types of weaving methods, such as plain weaving, twill weaving, and satin weaving, but plain weaving is preferable from the viewpoint of easy cutting during use. The thickness of the sheet is 0.03-3.
00 mm is preferable, and 0.03 to 0.30 mm is more preferable. Further, the fiber diameter of the glass fiber is preferably 3 to 10 μm.

The heat-resistant lubricant to be contained is 300
Any liquid lubricant that does not easily deteriorate or evaporate at a temperature of ℃ or higher may be used.Synthetic lubricating oils such as silicone oils, silicone greases, polyol ester oils, polyphenyl ether oils, and fluorinated hydrocarbon oils, or high-boiling oils And petroleum-based lubricating oils. Among them, silicone oil is particularly preferred.

The mixture layer 2 is a layer composed of a mixture of PTFE and a heat-resistant lubricant. The thickness of this mixture layer 2 is
It depends on the weave and shape of the glass cloth,
The thickness is preferably not less than the thickness covering the entire glass cloth.

The method of forming the mixture layer 2 is preferably a dipping method in order to sufficiently impregnate the heat-resistant lubricant and PTFE between the glass fibers. Specifically, a glass cloth is dipped and impregnated with a coating liquid obtained by adding a silicone oil or the like to a PTFE dispersion,
After drying at 100 ° C. for 1 to 5 minutes to sufficiently remove water, the mixture layer 2 can be formed by a method of sintering at 350 to 400 ° C. for 1 to 5 minutes. In addition, a heat-resistant lubricant and PTFE can be contained between the glass fibers of the glass fiber sheet layer 1 simultaneously with the formation of the mixture layer 2 by this method. By adopting a structure in which a part of the mixture layer 2 enters the glass fiber sheet layer 1 in this manner, the adhesive strength between the two layers can be increased, and the durability of the entire sheet can be further improved.

In the above case, the weight ratio of PTFE to silicone oil in the coating solution used is preferably from 9: 1 to 6: 4. When the weight ratio of the silicone oil is 5: 5 or more, the content of the heat-resistant lubricant between the glass fibers increases, so that the fibers are hard to be cut by slipping of the glass fibers, and the hand-cutting property tends to be poor. .

The PTFE layer 3 is a layer mainly composed of PTFE, and its thickness is preferably such that the surface becomes smooth, and varies depending on the shape and thickness of the glass cloth.

The method for forming the PTFE layer 3 is as follows:
The glass cloth substrate on which the mixture layer 2 is formed is made of PTFE
Dip coating on the dispersion, 80 ~
Dry at 100 ° C for 1-5 minutes, and at 350-400 ° C for 1
Sintering for 5 minutes, or (2) PTFE molding powder is compression molded, then sintered, and the molded product is formed into a sheet by a cutting method. A 0.03 to 0.10 mm PTFE film or polyimide film PTFE dispersion is coated on a carrier material such as aluminum or aluminum foil and dried at 80-100 ° C for 1-5 minutes.
A PTFE film having a thickness of 0.01 to 0.05 mm obtained by sintering at 00 ° C. for 1 to 5 minutes and releasing from the carrier material is applied to at least one surface of the mixture layer 2 at a temperature of 350 to 40.
A method of laminating with a hot roll at 0 ° C. may, for example, be mentioned.

As shown in FIG. 2, when the PTFE layer 3 is formed directly without the interposition of the mixture layer 2, a sheet material such as glass cloth is impregnated with a heat-resistant lubricant by a dipping method or the like. According to the above method (1) or (2), P
The TFE layer 3 may be formed.

The adhesive treatment layer 4 is a layer formed as needed to improve anchoring with the adhesive, and is formed by corona discharge treatment, sputter etching treatment, alkali metal etching treatment, low-pressure UV irradiation, or the like. You.

As the pressure-sensitive adhesive layer 5, an acrylic or silicone-based pressure-sensitive adhesive is used, and a silicone-based pressure-sensitive adhesive is preferable in consideration of heat resistance. The thickness of the adhesive layer 5 is 5
７０70 μm, preferably 20-50 μm. As a method for forming the pressure-sensitive adhesive layer 5, a reverse coating method, a fountain method, a dipping method, or the like is used.

Since the glass fiber composite sheet and the adhesive tape of the present invention as described above have higher durability than conventional products, they are used for heat sealing of bag making and packaging lines, guide portions and shooters that require mold releasability. It is useful for coating a hopper or the like, or for heat-resistant insulation protection.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and the like specifically showing the configuration and effects of the present invention will be described below.

Examples 1 to 6 PTFE dispersion D-2 (manufactured by Daikin, average particle size 0.2 μm) and silicone oil emulsion SH
8627 (made by Dow Corning Toray Silicone)
A coating solution mixed at a solid weight ratio of PTFE: silicone shown in Table 1 and diluted with distilled water so as to have a solid content of 40% by weight was applied to a glass cloth (KS10, manufactured by Kanebo).
80, a thickness of about 0.05 μm, and a fiber diameter of about 5 μm) by dipping and drying at 100 ° C. for 2 minutes.
Sintering was performed at 0 ° C. for 3 minutes. Next, PTFE dispersion D-2 (concentration: 60%) is applied to the sintered glass cloth by dipping, dried at 100 ° C. for 2 minutes, and dried.
Sintering was performed at 80 ° C. for 3 minutes, and the process was repeated until the total thickness became 80 μm.

On one side of the obtained sheet substrate, Ar gas,
Pressure 0.008Torr, were subjected to sputter etching under the condition of 30W sec / cm ^2. A silicone adhesive (manufactured by Dow Corning Toray Silicone, SH
4280) was diluted with toluene to a solid content of 40% by weight, coated by a reverse coating method so as to have a thickness of 40 μm, dried at 80 ° C. × 2 minutes, and dried.
The curing was performed at 3 ° C. × 3 minutes. The thickness of the obtained pressure-sensitive adhesive tape was 120 μm.

As a durability test of this pressure-sensitive adhesive tape, a commercially available heat sealing machine (manufactured by Fuji Impulse, FA-300-
Attached to the heating element and the pressing element of 10), and the heating time is 0.
Under a condition of 5 seconds and a cooling time of 1 second, a polyethylene bag having a thickness of 50 μm was continuously sealed. The heating element and the pressing element are both made of iron. Table 1 shows the results of evaluating the number of heat seals until the substrate is broken after the start of the test and the hand-cutting property as an index of workability. As a result, all the samples to which silicone was added did not break even after 23,000 times or more.
It had durability five times or more. However, regarding the hand-cutting property, when the silicone amount was 5: 5 or more, the fibers were hard to be cut due to slippage of the glass fibers, and the yarns were frayed due to the detachment of the fibers.

Comparative Example 1 An adhesive tape was prepared in the same manner as in Example 1 except that a coating solution prepared by diluting only PTFE dispersion D-2 with distilled water without using a silicone oil emulsion was used. Was prepared and evaluated. The results are shown in Table 1. The durability of this pressure-sensitive adhesive tape was lower than that of the example.

[0034]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing one example of an adhesive tape of the present invention.

FIG. 2 is a cross-sectional view schematically showing another example of the adhesive tape of the present invention.

[Description of Signs] 1 Glass fiber sheet layer (sheet-like material) 2 Mixture layer 3 PTFE layer 5 Adhesive layer S Glass fiber composite sheet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09J 7/04 C09J 7/04 C10M 107/50 C10M 107/50 147/02 147/02 169/04 169 / 04 // C10N 20:00 C10N 20:00 A 40:00 40:00 ZF term (reference) 4F072 AA04 AA08 AB09 AD07 AD47 4F100 AG00A AK18B AK18C AK52A AK52C BA02 BA03 BA07 BA10A BA10B BA13 CA19A DG01A DG12 EH46 EJ48EJ82J JJ03C JK02 JK04 JK09 JK16A JK16C JL00 JM01 4H104 CD02C CJ02A EA04A QA12 RA01 4J002 BD151 CF002 CH072 CP032 EB006 GJ00 4J004 AA10 AA11 AB03 CA05 CA07 CB01 CC03 CD01 CD05 CD10 FA04 FA05 FA06

Claims (4)

[Claims] 1. A glass fiber composite sheet in which a sheet made of glass fiber is coated with a polytetrafluoroethylene resin, wherein at least the sheet contains a heat-resistant lubricant between glass fibers. Characteristic glass fiber composite sheet. 2. A sheet-like material containing the heat-resistant lubricant is coated with a mixture layer of a polytetrafluoroethylene resin and the heat-resistant lubricant, and the mixture layer is coated with a polytetrafluoroethylene resin. The glass fiber composite sheet according to claim 1. 3. The glass fiber composite sheet according to claim 1, wherein the heat-resistant lubricant is silicone oil. 4. An adhesive tape comprising the glass fiber composite sheet according to claim 1 as a tape substrate.