JPH1060395A - Masking tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a masking tape which exhibits excellent solvent resistance and mechanical properties when applied and need not be forcibly peeled from the substrate after coating owing to its ability to be spontaneously dissolved or released by using a water-soluble or -dispersible film support and a pressure- sensitive adhesive layer. SOLUTION: This tape is obtained by applying 3-50g/m<2> of a pressure- sensitive adhesive prepared by making water-soluble or -dispersible by introducing hydrophilic groups into a pressure-sensitive adhesive component of a polyacrylic ester being a copolymer of an acrylic ester with a carboxylic or hydroxy monomer to either surface of a water-soluble or -dispersible PVA film support obtained by extruding a molten mixture of polyvinyl alcohol of a plasticizer through a T-die, inflation or casting an aqueous PVA solution over a hot roll. For example, 15g/m<2> of a water-soluble or -dispersible pressure- sensitive adhesive 2 is applied on either surface of a water-soluble film 1 made from a mixture prepared by mixing a base being a PVA having a degree of polymerization of 1,700 and a degree of saponification of 88mol% and 8wt.% plasticizer being glycerol to form a coating film having a thickness of 50×m.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-soluble or water-dispersible masking tape.

[0002]

2. Description of the Related Art When coating various objects such as automobiles and furniture, a masking tape is attached to a portion not to be painted or an end of a portion not to be painted, and is peeled off after the painting is completed. Conventionally, a masking tape in which an adhesive is applied to the back surface of a solvent-resistant paper tape or plastic tape has been known. However, conventional masking tapes require the masking tape to be peeled off after painting, so if the strength of the object is weak, the object will be damaged at the time of peeling, or in the case of a house wall, etc., after painting. There are problems such as difficulty in peeling the tape.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide excellent solvent resistance and mechanical properties when used, and to dissolve or peel off naturally by washing with water or leaving it for a certain period of time after coating. Therefore, it is an object of the present invention to provide a masking tape that does not require forced peeling after painting.

[0004]

Means for Solving the Problems The present inventors have proposed a water-soluble or water-dispersible polyvinyl alcohol (hereinafter referred to as PVA).
Abbreviated as ")" and a masking tape comprising a water-soluble or water-dispersible pressure-sensitive adhesive layer, and completed the present invention.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The water-soluble or water-dispersible PVA-based film substrate needs to have the property of being dissolved or dispersed in water. The dissolving time or dispersing time in water includes those that dissolve or disperse immediately upon application of water and those that dissolve or disperse after several months. PVA is a saponified product of a polymer of a vinyl ester such as vinyl acetate, and is usually formed by casting an aqueous PVA solution on a hot roll. The film substrate of the present invention can also be obtained by hot-melting a mixture of PVA and a plasticizer and extruding a film from a T-die or by inflation. PVA serving as a film substrate can control solubility in water by changing the degree of saponification. That is, it is possible to control to various levels of water solubility or water dispersibility such as a film having a high dissolution rate, a film having a low dissolution rate in cold water, and a film dissolving or biodegrading after several months. The saponification degree of PVA is 50 to 100 mol%
More preferably, it is 70 to 99.5 mol%. PV
The viscosity average degree of polymerization of A (hereinafter abbreviated as degree of polymerization) is related to the strength and toughness of the film, and is usually 5 degrees.
It is from 00 to 8000, preferably from 1,000 to 4,000. In order to adjust the solubility or dispersibility in water, a modified PVA in which a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a polyoxyethylene group, a quaternary ammonium base, or the like is introduced into PVA is also used. be able to.

[0006] A plasticizer can be added to PVA in order to maintain the moisture retention of the film substrate and the flexibility at low temperatures. Examples of the plasticizer include glycerin, polyethylene glycol, diglycerin, diethylene glycol, glycerin, and a compound obtained by adding ethylene oxide to sorbitol. The added amount of the plasticizer is preferably 5 to 50% by weight based on PVA. Furthermore, in order to impart the form stability of the film substrate, clay, talc, calcium carbonate, inorganic fillers such as mica, glass fiber,
A film to which reinforcing fibers such as cellulose fibers and vinylon fibers are added can also be used. The thickness of the film substrate is usually 10 to 500 μm in consideration of the strength, toughness, dissolution rate in water, and the like of the tape. Further, the film base film may be embossed or matted.

Various water-soluble or water-dispersible pressure-sensitive adhesives for use in the present invention are known. In particular,
A copolymer of an acrylic ester and a monomer having a carboxyl group or a hydroxyl group, wherein a hydrophilic group such as a carboxyl group (a salt thereof) or a hydroxyl group is imparted to an adhesive component of the polyacrylic ester, and a water-soluble or It is water-dispersible.

[0008] The masking tape of the present invention is produced by applying an adhesive to one surface of a film substrate.
The coating amount of the pressure-sensitive adhesive is preferably 3 to 50 g / m ² , more preferably 5 to ²⁰ g / m ² per one side. Usually, the pressure-sensitive adhesive is applied to one surface of the film substrate over the entire surface. However, in some cases, the pressure-sensitive adhesive may be applied in a dot or block shape on the film to increase the dissolution rate or improve flexibility.

When working using the masking tape of the present invention, a coating layer for protecting the pressure-sensitive adhesive layer can be provided outside the water-soluble or water-dispersible pressure-sensitive adhesive layer.
Examples of the coating layer include a release paper or a release film that protects the pressure-sensitive adhesive layer and allows the pressure-sensitive adhesive layer to be peeled off and adhered when used. The masking tape of the present invention has a tape shape, and its width and length are not particularly limited, and are set to appropriate widths and lengths as needed. Usually 0.5 width
５０50 cm is suitable, preferably 1-10 cm.

Although the masking tape of the present invention is preferably flexible, elongation is often not required. This is because if the elongation is too large, it may be difficult to precisely fix it to a certain portion. For this reason, a water-soluble or water-dispersible paper or nonwoven fabric may be laminated on the masking tape of the present invention, or a glass fiber or a vinylon fiber may be added to the masking film to suppress the elongation appropriately. The masking tape of the present invention is usually transparent or translucent, but it can be colored or opaque tape in some cases. For example, a method of adding a dye or pigment to a PVA aqueous solution to form a film. There is. That is, an opaque colored tape can be produced by adding a white pigment such as titanium oxide or calcium carbonate. These treatments do not impair the water-soluble or water-dispersible properties of the tape of the present invention.

The masking tape of the present invention does not need to be peeled off by applying force after painting, and can be washed with water,
If left for a certain period of time, it will be dissolved and removed by the elements.
Note that the masking tape of the present invention may be peeled off by applying force by hand or the like after painting, like a conventional general masking tape.

[0012]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. Unless otherwise specified, “%” and “parts” mean “% by weight” and “parts by weight”, respectively.

Example 1 FIG. 1 is a longitudinal sectional view showing the structure of a water-soluble masking tape of the present invention. A water-soluble film 1 as a substrate and a water-soluble or water-dispersible pressure-sensitive adhesive on one side of the film 1 are shown. 2 is applied to the entire surface. Here, the water-soluble film is mainly composed of PVA having a polymerization degree of 1700 and a saponification degree of 88 mol%, and glycerin is used as a plasticizer with respect to PVA by 8%.
This is the film to which the film was added. The water-soluble adhesive is a water-soluble adhesive obtained by copolymerizing butyl acrylate, octyl acrylate, methyl acrylate, sodium salt of methacrylic acid and sodium salt of acrylic acid. The thickness of the water-soluble film of the substrate is 50 μm, and the coating amount of the water-soluble adhesive is 15 g / m ² . To decorate a home fence, two lines of 10 cm in width were inserted, and the unpainted portions were masked using the masking tape of the present invention and spray-painted from above. Two days later, after the paint had hardened, the masking tape dissolved in about 1-2 minutes when showered with water, and could be completely removed, and two clean lines appeared.

Example 2 Modified PV containing a polymerization degree of 1700, a saponification degree of 96 mol% and maleic anhydride of 2 mol% in place of the PVA of Example 1.
A film was prepared in the same manner as in Example 1 except that A was used, and a tape having a width of 30 mm was prepared. In order to paint the window frame using this masking tape, the entire edge of the glass was masked. After painting with a brush,
After the paint was completely cured, the masking tape was dissolved by washing with water and completely removed.

[0015]

The masking tape of the present invention has a function not found in conventional masking tapes because the base material and the pressure-sensitive adhesive layer are water-soluble or water-dispersible. For example, after masking and painting the walls and walls of a house, the masking tape can be peeled off without applying force by leaving it as it is or letting it water. In addition, after masking and painting on the surface where the strength of the painting object is very weak,
By washing with water, the masking tape can be peeled off without applying force. The PVA-based film substrate in the masking tape of the present invention has excellent strength and toughness, and is also excellent in weather resistance. Used for applications. In addition, since it has excellent solvent resistance, the masking tape does not swell or break, and the paint does not penetrate the tape, even when applied to paints, paints, thinners, and the like.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a water-soluble adhesive tape for grafting according to the present invention.

[Explanation of symbols]

 1: water-soluble film base material 2: adhesive

Claims (1)

[Claims] 1. A masking tape comprising a water-soluble or water-dispersible polyvinyl alcohol-based film substrate and a water-soluble or water-dispersible pressure-sensitive adhesive layer.