JPH09156017A - Release sheet and self-adhesive waterproof sheet using the release sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dissipate the charge generated at the time of release and prevent the static shock by forming an optional face into a release-treatment given layer in the case of a filmy base material conductive in itself, and a face on the opposite side to a conductive layer in case of a filmy base having non- conductivity in itself, provided with a conductive layer. SOLUTION: As a filmy base having conductivity itself, a plastic film, a paper, a non-woven cloth or a woven cloth can be used. As a filmy base having conductivity itself, a plastic film blended with a conductive material can be used. A conductive layer 2 is formed on one face of the filmy base 1 having non-conductivity itself, and a release property treatment layer 3 is formed on the opposite face thereof on a release sheet A. The release property treatment layer 3 is formed on a filmy base 4 having conductivity itself on a release sheet B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release sheet that does not cause electrostatic shock and a self-adhesive waterproof sheet using the release sheet.

[0002]

[Problems of the prior art] Among building waterproofing, asphalt waterproofing has the most achievements and is still the mainstream seat. This typical construction method is a thermal construction method in which asphalt is heated and melted at 250 ° C to 300 ° C at the construction site, and is used in comparison with neighboring environmental pollution due to smoke and odor generated at that time and other waterproof construction methods. Improvements to the need for more process steps are eagerly needed. One of the possible solutions to these problems is a modified asphalt waterproof self-adhesion method using a modified asphalt roofing provided with a self-adhesive layer (hereinafter referred to as a self-adhesion layer).

This construction method (a) does not use fire or fuel at the time of construction, so that a clean neighborhood environment is always maintained. (B) Labor saving because a waterproof layer is formed in one or two steps.
It has the features that it can save layers and that (c) does not use molten asphalt, so a clean finish can be obtained.
Not only architectural waterproofing but also civil engineering waterproofing is steadily spreading. Apart from the above flow, asphalt roofing with a self-adhesive layer is very often used just under various roof finishing materials for general houses for the purpose of waterproofing and moisture proofing.

There is a demand for improvement in these self-adhesive construction methods for many years. That is, in this construction method, a method of adhering the self-layer surface to the foundation 13 of the construction while peeling the release sheet 11 from the asphalt roofing 12 is used. Electrostatic force is generated by the frictional force of and the accumulated charge flows to the worker 14 (see A to E in FIG. 2). The electric shock at that time is extremely disliked, and in some cases, the recoil of the electric shock may cause the worker to fall from the roof or roof or to give a shock to the heart, which may affect human life. In addition, when work in a different industry that uses a large amount of solvent, such as painting, is being carried out in the vicinity, there is a concern that a spark fire may occur due to the vapor of the solvent volatilized by an electric shock.

The mechanism by which static electricity is generated at the time of peeling off the release sheet 11 has not been completely clarified, but the following stepwise generation is presumed by electrical analysis. (1) When the release sheet 11 is peeled off, the pressure-sensitive adhesive surface c of the peeled off portion is positively charged and the peeling surface b of the release sheet 11 is negatively charged (see A in FIG. 2). (2) The electric charge on the peeling surface b causes the positive electric charge on the non-peeling surface a of the peeled release sheet to induce polarization (see B in FIG. 2). (3) The electric charge on the non-peeling surface a causes induced polarization of the negative electric charge on the non-peeling surface a ′ of the release sheet in a state where the release sheet 11 is not peeled off (see C in FIG. 2). The electric charges induced at this time rapidly increase on the non-peeling surface a ′ surface as the peeling sheet 11 is peeled off. (4) The electric charges on the non-peeling surface a ′ cause positive polarization in a lump form in the space near the non-peeling surface a ′ (see D in FIG. 2). (5) The charges induced by polarization in (4) above are the non-peeling surface a.
Negative charges are massively induced and polarized in the space near (Fig. 2
See E). (6) Since the release sheet 11 is usually made of paper or a plastic film, its conductivity is extremely small,
There is no escape for charged charges.

Therefore, depending on the weather conditions, if the worker 14 touches that portion, he will receive an electric shock. In particular, it becomes easier to be charged in low humidity weather conditions,
Remarkably susceptible to electrical shock. As a measure against this problem, a method of wearing gloves knitted with conductive fibers and eliminating static electricity by corona discharge has been proposed, but the gloves are expensive, and the peeling sheet 11 does not need to be peeled off. The fact is that it has not become widespread because it becomes difficult.

[0007] In general, as a measure for charging the adhesive paper,
The following methods have been proposed. A method of removing the electric charge accumulated at the end of the pressure-sensitive adhesive sheet by short-circuiting the surface of the pressure-sensitive adhesive label and the backing surface of the release paper with a conductive wire (JP-A-54-63139). A method of applying an electrostatic voltage between the front surface and the back surface of the pressure-sensitive adhesive sheet to neutralize the charge accumulated at the end by giving a charge of opposite sign (Japanese Patent Laid-Open No. 54-63700). A method in which ionized air is applied to the surface of the pressure-sensitive adhesive sheet during the peeling process to eliminate accumulated charges (Japanese Patent Laid-Open No. 54-106547). A method in which an insulating substance is applied to the backing surface of a release paper so as to increase the electric resistance and prevent electric charges from being transferred to the end when peeling (JP-A-56-16574). However, these methods also lack practicality.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel release sheet which can release the electric charge generated when the release sheet is released. Another object of the present invention is to provide a self-adhesive (hereinafter abbreviated as self-adhesive) waterproof sheet that does not give an electrostatic shock to an operator during peeling.

[0009]

One of the aspects of the present invention is to provide a film-like base material which itself has conductivity or a non-conductive film-like base material provided with a conductive layer in the former case. Relates to a release sheet having an optional surface, and in the latter case, the surface opposite to the conductive layer is a release treatment layer.

Another aspect of the present invention is that the release sheet according to claim 1, 2, 3 or 4 is temporarily adhered to the surface of the self-adhesive layer of the waterproof sheet having the self-adhesive layer. Regarding tarpaulin.

The non-conductive film-like substrate itself may be a plastic film, paper, non-woven fabric or woven fabric. When it is used as a release sheet for a self-adhesive waterproof sheet, the plastic film is used. Alternatively, it is preferable to use paper.

Examples of the film-like substrate which is itself conductive include a plastic film containing a conductive material. It is conceivable to form the conductive layer only with a polymer having conductivity itself, but in this case, the cost becomes extremely high.

In order to impart conductivity to the non-conductive film base material itself, a conductive paint can be used. As the conductive paint, it is possible to use a usual one in which a conductive material is mixed with a binder and a solvent or water is used as a dispersion medium.

As the conductive material, carbon black,
Examples of the powder include metal powder and conductive polymer powder, but when used as a release sheet for a self-adhesive waterproof sheet, carbon black is sufficient. The conductive material consequently has a surface resistivity of 10 ⁸ Ω or less, preferably 1
It is used in such an amount that it becomes 0 ⁷ Ω or less.

In the case of a release sheet used as a self-adhesive waterproof sheet, the color of the release sheet does not matter, so that the conductive coating material containing the cheapest carbon black as a conductive material is itself non-conductive. It is preferable to form the conductive layer on the film-like substrate (1) such as a plastic film or paper.

The conductive coating material is 15 to 35 parts by weight, preferably 20 to 30 parts by weight, of a general-purpose organic binder such as acrylic, acrylic urethane, acrylic-styrene, urethane, urethane or vinyl chloride. 10 to 30 parts by weight of carbon black, preferably 1
0 to 20 parts by weight, as a dispersion medium, 55 to 75 parts by weight of water in the case of emulsion, preferably 60 to 70 parts by weight, 55 to 75 parts by weight in the case of solvent, preferably 65 to 7 parts
0 parts by weight can be used. The coating amount of the conductive paint is 1.5 × 10 ⁻⁴ to 4 × 10 ⁻⁴ g / cm ² , preferably 2 × 10 ^{−4 to} 3 × 10 ⁻⁴ g / cm ² .

In order to form the release treatment layer, it is common to apply a silicone resin such as organosilane, organosiloxane, silicone oil (eg, dimethyl silicone oil) or silicone oil. Any material that does not have an affinity for the agent can be used.

As the self-adhesive type waterproof sheet, all known self-adhesive type waterproof sheets can be used, and the applicants have proposed Japanese Patent Application Nos. 3-23021 and 6- Of course, a self-adhesive waterproof sheet such as No. 212136 can also be used.

[0019]

The present invention will be described below with reference to examples.
The present invention is not limited thereby.

Example 1 (1) Release sheet (a) Membrane substrate: 100 μm polyethylene terephthalate (PET) film. (B) Conductive paint: Polyurethane resin 20.7% by weight Carbon black 10.0% by weight Solvent 69.3% by weight (c) Release agent: Silicone resin (Specifically) (a) with (c) Apply 2 μm thick and (b) on the other side.
It was applied at a rate of 0 g / m ² and dried to prepare a release sheet. (2) Self-adhesive waterproof sheet with release sheet Mineral powder / modified asphalt / PET spun bond 100
g / m ² from the consisting substrate layer / modified asphalt / adhesive layer / it was the made of the release sheet configuration. The pressure-sensitive adhesive was composed of SBS 20% by weight Takifire 20% by weight Petroleum-based process oil 20% by weight Straight asphalt 40% by weight, and the thickness of the adhesive layer was 0.5 mm. The modified asphalt is compounded as follows: SBS 15% by weight, straight asphalt 85% by weight. The thickness of the self-adhesive waterproof sheet was 2.0 mm.

With respect to the antistatic effect of the self-adhesive waterproof sheet with release sheet, almost satisfactory results are obtained when the surface resistance value is 10 ⁸ Ω or less. The value will be displayed.

After peeling off the release sheet of the self-adhesive waterproof sheet under the conditions of 0 ° C. and 20% absolute humidity, the surface resistance values on both sides of the release sheet were measured. The results are shown in the table below.

[0023]

[Table 1]

Although the release sheet is not subjected to a conductive treatment, the non-peelable treated surface and the releasable treated surface have a surface resistance value of the order of 10 ¹⁴ Ω or more, and therefore a large electrostatic shock is given to a peeling operator. Was given. When the release sheet provided with the conductive layer of the example is used, as shown in the above table, 1
Since it had a surface resistance value on the order of 0 ⁷ Ω, it never caused an electrostatic shock.

Method for Measuring Surface Resistance Value Equipment Used (1) Super Insulation Meter SM-8210 [Toa Denpa Kogyo KK] (2) Electrode MODEL P-616 [(Inc.)
Kawaguchi Denki Seisakusho Co., Ltd.] The measurable range of the above model is 1.0 x 10 ⁷
~ 3.7 × 10 ¹⁶ Ω, and if you want to measure a low resistance value of 1.0 × 10 ⁷ Ω or less, use a digital multimeter SC-7401 (made by Iwatsu Electronics Co., Ltd.) instead of the super insulation meter.
Is used. ○ Size of test piece MD100mm × TD100mm ○ Measurement condition (1) Room temperature condition Temperature 20 ° C Humidity 65% RH (2) Applied voltage 100V (3) Applied time 40 seconds (Change switch "DISC"
(HARGE ”→“ CHARGE ”) (4) Measurement Immediately change the switch to“ MEASURE ”from the state of (3) and read the value after 20 seconds. ○ Data Calculated from the following formula and rounded the average value of 3 points to 2 significant figures to obtain data. ○ How to measure (a) Before setting the sample, wipe off the dirt on the conductive rubber surface of the electrode with methyl alcohol or the like. (B) The sample is set on the electrode in the shield box in the surface resistance measuring device of FIG. The measurement surface is on the upper side. (C) Screw the variable pressure knob to fix the electrode to the sample. For the same sample, the pressure should be constant. The super-insulation meter is energized in advance to be in a use state (a state aged for about 30 minutes).

[0026]

[Effect] According to the present invention, the operator can be completely relieved from the electrostatic shock that occurs when the release sheet is peeled off. Prevention of electrostatic shock by the release sheet of the present invention is extremely simple as compared with the conventional preventive means, and is extremely practical. The release sheet of the present invention is extremely useful as a release sheet for a self-adhesive sheet such as a self-adhesive waterproof sheet, a self-adhesive wallpaper, or a self-adhesive bran paper.

[Brief description of the drawings]

FIG. 1 shows the structure of a release sheet of the present invention. A is a conductive layer 2 on one surface of the film-like substrate 1 which is non-conductive itself.
Is a release sheet having the releasable treatment layer 3 provided on the opposite surface thereof, and B is a release sheet having the releasable treatment layer 3 provided on the membranous base material 4 which is itself conductive.

FIG. 2 is a model view showing a series of movements A to E in which a series of movements in which a release sheet is charged when it is peeled from a waterproof sheet and which gives an electrostatic shock to an operator.

FIG. 3 is a schematic view showing a surface resistance measuring device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Membrane base material (non-conductive) 2 Conductive layer 3 Releasable treatment layer 4 Membrane base material (conductive) 11 Release sheet 12 Asphalt roofing 13 Base of construction 14 Worker a Release surface a'Non-release surface before release of release sheet b Release surface when release sheet is released c Adhesive surface

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Kojima 1-3-1 Kodai, Adachi-ku, Tokyo Tajima Roofing Co., Ltd.

Claims (5)

[Claims] 1. A film-like base material which itself has conductivity or a non-conductive film-like base material which is provided with a conductive layer, in the former case any surface, in the latter case, A release sheet, characterized in that the surface opposite to the conductive layer is a release treatment layer. 2. The surface resistivity of the conductive layer is 10 ⁸ Ω.
The release sheet according to claim 1, which is as follows. 3. The release sheet according to claim 1, wherein the non-conductive film-like substrate itself is a plastic film, paper, non-woven fabric or woven fabric. 4. The release sheet according to claim 1, wherein the film-shaped substrate having conductivity by itself is a plastic film in which a conductive material is kneaded. 5. A self-adhesive type waterproof sheet, wherein the release sheet according to claim 1, 2, 3 or 4 is temporarily adhered to the self-adhesive layer surface of a waterproof sheet having a self-adhesive layer.