JPS604579A - Pressure-sensitive adhesive tape or sheet for masking - Google Patents

Abstract

PURPOSE:To provide a tape or sheet which can be released from the adherend only by heat-treatment and is suitable as a masking material for painting, by laminating a film having high thermal shrinkage to another film base, and applying a pressure-sensitive adhesive layer to the obtained heat-shrinkable substrate. CONSTITUTION:A surface of a film base A (e.g. a film of PE, PP, PVC, etc. having the longitudinal and lateral thermal shrinkages defined by the formula of preferably 0-80% after the heat-treatment at 60-200 deg.C for 0.1-30min) is laminated via an adhesive layer with another film base B having higher thermal shrinkages than the film base A (preferably having the above-defined thermal shrinkages of 10-90% and 1.5-3 times those of the base B) to obtain a heat-shrinkable substrate. The objective tape or sheet can be manufactured by applying a pressure-sensitive adhesive layer to the surface of the film base A of the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a pressure-sensitive adhesive for masking that is used for masking during painting work, temporary surface protection, etc., and is extremely easy to peel off after achieving the purpose of adhesion. The tape still concerns Sea I.

When applying paint to various objects, pressure-sensitive adhesive tapes or sheets are often used to mask areas that do not require painting. In other words, apply a pressure-sensitive adhesive tape or sheet to areas that do not require painting, apply paint to the entire song including this tape or sheet, and then peel off the tape or sheet after the paint has dried. Then, the part to which this tape or sheet was attached becomes a non-painted part. By using an adhesive tape or sheet for masking during painting in this way, painting can be done efficiently and the boundary line between painted areas and non-painted areas can be clearly drawn.

However, when removing the adhesive tape sheet after the paint has dried, depending on the size and shape of the non-painted area, it may take time to peel off the edge of the tape sheet to create a trigger for peeling, or this tape or There was a problem in that the efficiency of the peeling operation was low, such as having to peel the sheets one by one manually.

Pressure-sensitive adhesive tapes or sheets are still used to temporarily protect the surface of an object, and the same problem occurs when peeling off this tape or sheet.

Therefore, the inventors conducted extensive research with the aim of providing a masking pressure-sensitive adhesive tape or sheet that can be peeled off from an adherend with good workability after achieving the attachment purpose, and found that the support material is heat-shrinkable. We discovered that when a pressure-sensitive adhesive tape or sheet is used for masking during painting, the tape or sheet naturally peels off from the adherend simply by heating, greatly improving the efficiency of the peeling process. This invention has been made.

That is, in this invention, a film-like base U'B consisting of at least one film having a higher heat shrinkage rate than that of the film-like base material A on one side of the film-like base material U'A is provided with an adhesive. A heat-releasable masking pressure-sensitive adhesive tape comprising a heat-shrinkable liquid support laminated through layers and a pressure-sensitive adhesive layer provided on the film-like base A side of this support; or This relates to the seat.

The pressure-sensitive adhesive tape or sheet for masking of this invention is applied to an adherend for masking during painting work, temporary surface protection, etc., and after achieving the purpose of application, this tape or sort is applied. When peeling off from the body, simply heat the tape or sheet, and the tape or sheet will naturally peel off due to the heat shrinkage stress of the support. Compared to peeling off with a large width, the work efficiency can be improved.

In particular, when the adhesive tape or sheet of the present invention is used for masking during painting work, the support shrinks due to the heat generated when the applied paint is heated and dried, causing the tape or sheet to become attached to the adherend. Since it can be peeled off from the surface, no special peeling time is required, which is extremely convenient.

Moreover, the pressure-sensitive adhesive tape or sheet for masking of the present invention uses a laminated layer of at least two types of film-like base materials having different heat shrinkage rates as a support, and this tape or sheet is applied to an adherend. The heat shrinkage rate of the film-like base material H'B, which becomes the outer surface of this tape or sheet when applied, is higher than that of the film-like base material A, which becomes the adherend side. When the sheet is thermally peeled from the adherend, the outer surface of the tape or sheet is rolled inward and peeled off. Peeling occurs quickly and almost completely; The peeling efficiency can be further improved compared to using a support having a shrinkage rate.

The film-like base material A in the masking pressure-sensitive adhesive tape or sheet support of this invention is 60 to 2
An unstretched plastic film having a heat shrinkage rate of usually 0 to 80% in the longitudinal and lateral directions, respectively, as expressed by the following formula when heated at 0.00°C for about 1 to 30 minutes, or (d - stretched in at least one direction) Examples include stretched plastic films (hereinafter referred to as stretched plastic films).

Vertical or horizontal length before heating Most plastics made of polyethylene, polypropylene, polyvinyl chloride, polyester, polystyrene, etc. are used as materials for the plastic film, regardless of whether they are crystalline or amorphous. be able to. When a stretched plastic film is used as the film-like base material A, the stretching direction and stretching ratio of this film may normally be either uniaxial stretching or biaxial stretching, and the stretching ratio may be within the range of the heat shrinkage rate mentioned above. This may be determined depending on the type of plastic film used, but it is usually about 12 to 5 times.

The film-like base material B laminated on one side of the film-like base material A is composed of at least one type of film having a heat shrinkage rate higher than that of the film-like base material A. Usually, this film-like base material B is 6
0-200'C10, heating for about 1-30 minutes 6
The heat shrinkage percentages in the longitudinal and transverse directions expressed by the formula 0 are about /"lio~90%, respectively, and the heat shrinkage percentages in the longitudinal and/or transverse directions are respectively in the same direction of the film-like base material A. A stretched plastic film with a heat shrinkage rate of 1.3 times or more, preferably about 15 to 3 times, is used.

As the material for this plastic film, those exemplified for the film-like base material A are used in the same way, and the type of this month may be the same as or different from that of the film-like base material A. The stretching conditions for the plastic film are determined so as to satisfy the heat shrinkage rate range described in 1]0, taking into account the adhesive force of the pressure-sensitive adhesive tape or sheet when binding the sheet, the purpose of use, etc. Ordinarily, either uniaxial stretching or biaxial stretching may be used, and the stretching ratio is 1.
It is said to be about 3 to 7 times larger.

As for this film-like base material B, as mentioned above, 1
In addition to using different types of stretched plastic films, depending on the purpose, two types of stretched plastic films that satisfy the heat shrinkage rate of 110 and have different heat shrinkage rates, etc.
It may be laminated with two adhesive layers interposed therebetween to form a multilayer structure.

Note that when the film-like base material B has such a multilayer structure, the order in which the films are laminated is not particularly limited, but when laminating films with different heat shrinkage rates, the magnitude of the heat shrinkage rates It is preferable to laminate the films in order, and use the film with the smallest thermal shrinkage rate as the film-like base material A side.

In the film-like base material B having such a multilayer structure, each film is bonded to such an extent that peeling does not occur between the layers of the base material B when the pressure-sensitive adhesive tape or sheet is thermally peeled off from the adherend. Must have been. The adhesive used for this purpose is the film-like group E', which will be described later.
The adhesive used when laminating A and film-like base material B can be used in the same way.

As the support for the pressure-sensitive adhesive tape spanning sheet for masking of the present invention, a laminate of the above film-like base material A and film-like base material B is used. An adhesive tape is one that can provide an adhesive force that does not cause peeling between these base materials when the sheet is thermally peeled, that is, an adhesive force that is greater than the adhesive force of the adhesive tape or sheet to the adherend. If so, there are no particular limitations.

In addition, when laminating these film-like substrates A and B, if one or both adhesive surfaces are polyolefin-based such as polyethylene or polypropylene and have low affinity with the adhesive used, fd, these adhesive surfaces It is desirable to increase the wetting tension by subjecting the material to various commonly used surface treatments such as corona discharge treatment and ultraviolet irradiation treatment. Incidentally, it is preferable that such surface treatment be applied in the same manner when forming the film-like base material B described in +jfJ into a multilayer structure depending on the type of film and adhesive used.

Next, as the pressure-sensitive adhesive used for providing the pressure-sensitive adhesive layer on the film-like base material A side in the pressure-sensitive adhesive tape or sheet for masking of the present invention, when masking the surface of the adherend, The masking pressure-sensitive adhesive tape or sheet is given enough adhesive strength to prevent it from peeling off from the adherend, and when heated, the masking pressure-sensitive adhesive tape or sheet can be easily covered without leaving any adhesive as the support shrinks due to heat. There are no particular limitations on adhesives as long as they can be peeled off from the adherend, but preferred examples include inbutylene, acrylic ester adhesives, natural rubber adhesives, etc.A small amount of tackifier may be added to these pressure-sensitive adhesives. It may be crosslinked to improve adhesive strength, prevent adhesive residue, or improve thermal releasability.

Nao, polyethylene film as film-like base material A;
When using a polyolefin film such as polypropylene film, depending on the type of pressure-sensitive adhesive used, various treatments such as corona discharge treatment and ultraviolet irradiation treatment are usually performed on the surface to which the adhesive is applied to improve affinity. It is desirable to perform surface treatment to increase wetting tension.

To obtain the pressure-sensitive adhesive tape or sheet for masking according to the present invention, for example, a pressure-sensitive adhesive layer is provided on one side of a filter-like base material, and an adhesive layer is provided on the other side of this base material A. The film-like base material B may be laminated via an adhesive layer, or the film-like base material A and the film-like base E may be laminated together.
'B may be laminated in advance via an adhesive layer, and then a pressure-sensitive adhesive layer may be formed on the film-like base material A side, and the present invention is not limited thereto.

However, when providing a pressure-sensitive adhesive layer or an adhesive layer for bonding and laminating the base materials to each other on the film base material, the film base material is stretched, and these adhesives are applied to the base material. When drying with heat 1#+ after coating, it is necessary to dry at a temperature at which the base material does not shrink due to heat. Further, if necessary, it is also possible to provide a non-stretched plastic film with these adhesive layers and then stretch it to obtain a film-like base material having the required heat shrinkage rate. Examples of such a film include: For example, a stretched plastic film made of an amorphous polymer such as polyvinyl chloride or polystyrene may be used as the film-like base material.

Note that the method of forming the adhesive layer as described above depends on the type of film used and the drying conditions of the adhesive when forming the film-like base material B into a multilayer structure.

Obtained as described in -1-)1. The pressure-sensitive adhesive tape or sheet for masking according to the present invention comprises a heat-shrinkable support formed by laminating a film-like base material B on one side of a film-like base material A with an adhesive layer interposed therebetween, and It consists of a pressure-sensitive adhesive layer provided on the film-like base material Δ side, and the thickness of each layer is usually 5 to 1.0 on the film-like base U'A.
0 to 1 m, the film-like base material B (total thickness of each film and the adhesive layer between each film if composed of two or more films) is 10 to 300μ77L1, and the adhesive layer between these bases is 05 to 5~ with 301m7L1 pressure sensitive adhesive layer
It is about 200/L7n.

Also, this adhesive tape or sheet can be
C.01 - After heating for about 30 minutes, 1) the support described in fj still exhibits a heat shrinkage stress greater than the adhesive strength of the tape to the adherend.

In addition, this pressure-sensitive adhesive tape or sheet for masking usually has a 180° peel adhesion strength of 50 to 1,000 y/20 t to a 5PC-class Flight '471 board.
It is about hm wide.

This adhesive tape or t/'J: After pasting the sheet on the adherend, it is usually peeled off at 60-200°C.
All you need to do is heat it for about 30 minutes. Especially when used for masking during painting work, the paint drying conditions, usually 1
If the heat shrinkage stress of the support and the adhesive strength of the tape or sheet are set so that heating at 00 to 200'C for about 1 to 30 minutes (v group 11) can be achieved, no special peeling time is required. do not.

Peeling the masking pressure-sensitive adhesive tape or sheet after pasting is possible by simply heating it as described in OQ, but it is also possible to remove it by simply heating it as described in OQ, but it is also possible to remove it by simply heating it, or by blowing a gas (e.g. air) after heating, or by blowing hot air as a means of heating. When it comes to peeling β11
This is a significant reduction in one hour. In addition, if the adherend has poor heat resistance, the adherend may be heated or blown with gas after heating. In particular, when using a tape or sheet with a wide area, the suction information 11iiF is added to the heating or heating and gas blowing means described in 10.
, auxiliary means such as means can be used. The use of such an auxiliary means is such that the edges j71≦ or peeled off by heating etc.
This has the effect of increasing the peeling speed of the large-sized tape or sheet.

As described in detail above, the pressure-sensitive adhesive tape for masking according to the present invention can be simply peeled off by heating after being applied to a stone object, which makes it possible to remove the masking pressure-sensitive adhesive tape from conventional tapes or sheets. Peeling workability is improved by a factor of 1 compared to sheets. It should be noted that the thermal peeling method using tape No. 1 or No. 1-1 of the present invention can be applied to various adhesive fields other than masking.

Next, examples of this invention will be described. In addition, in the following, even though it is written as "part", it is assumed that "single hj part" is omitted.

Example 1 Thickness made of soft polyvinyl chloride obtained by blending 30 parts of dioctyl phthalate as a bqJ agent with 100 parts of polyvinyl chloride (degree of polymerization 1.00)], OOnot7
A 7-inch film was stretched 25 times in a 100°Ci trowel cross-body using a Bistron-type stretching tester made by Iwamoto Seisakusho to obtain a 40-17 film.
A film-like base vJ'B made of a stretched film with a thickness of 72 mm was obtained.

On the other hand, an unstretched film with a thickness of 50 knots 7?1 made of soft polyvinyl chloride having the same composition as in Nj4i7 was used as the film-like group kA'A, and on one side of this unstretched film was coated with an acrylic pressure-sensitive adhesive A (phthyl acrylate-1). A copolymer consisting of 95 parts of 2-hydroxyethyl acrylate and 5 parts of 2-hydroxyethyl acrylate to which 5 ijl≦ of an incyanate crosslinking agent was added was diluted to a thickness of 10 to 1711 mm and heated at 120°.
A pressure sensitive adhesive layer A was formed by heating and drying at C for 5 minutes.

The other side of this film was coated with acrylic adhesive B (copolymer consisting of 95 parts of phthyl acrylate and 5 parts of acrylic acid to which 5 r:+s of incyane-1 crosslinking agent was added) in 3 parts% toluene. The thickness after drying the solution is 2 months! Adhesive layer B was formed by applying 77L and drying with 'M 2AK.

In this way, the film-like base 44'A has the adhesive layer B on the adhesive layer B side of the adhesive layer B, and the film-like base 44'A has the adhesive layer B on the other side. The above-mentioned stretched film was attached to obtain a heat-peelable pressure-sensitive adhesive sheet for masking.

This adhesive sheet was cut into a size of 5 cm x 5 cm and used as a sample sheet, and this sample note was attached to the center of a SPC-grade flight steel plate with a size of 10 cm x 10 cm. And this sample Sea 1-, l
An acrylic emulsion type paint was applied to the entire surface of the steel plate, including the coating, to a coating thickness of 10)27+1. Next, this steel plate was left in a hot air dryer at 130°C for 10 minutes to dry the coated surface. When the steel plate was taken out from the dryer by blowing, the sample sheet described in fj had shrunk into a cylindrical shape with the film-like base material B inside, with the center part of the steel plate almost completely peeled off. I-I was able to remove it without any effort by simply picking it up with my fingers. However, the masking effect was still sufficient in the area where the sample tape was attached at the center of the steel plate.

The pressure-sensitive adhesive sheet for masking obtained in Example 1 had a 180 peel adhesion strength of 70 y to the steel plate.
/ 201Hm wide, and the heat shrinkage rate in the lateral direction of this sheet when heated in hot air at 85°C for 15 minutes (
Bow, 5% for film-like base material A, 40 for film-like base material B
%Met.

Example 2 Thickness 2 made of soft polyvinyl chloride with the same composition as Example 1
00) The film of 17H shown in Example 1 was stretched vertically, horizontally, and twice as much in a JOO'C using the same stretching tester as in Example 1 to obtain a film-like base material B consisting of a stretched film with a thickness of 5011 parts. I got it.

On the other hand, an unstretched film with a thickness of 50 mm and 71 mm obtained by blending 50 parts of polyethylene and 50 parts of polypropylene was used as the film-like base material A, and one side of this film was subjected to corona discharge treatment to give a wetting tension of 41 dyne/c+n. did.

Polyimbutylene (molecular weight 1
200,000) to a thickness of 10 mm to form a pressure-sensitive adhesive layer A, and the same acrylic adhesive B shown in Example 1 was applied to the corona discharge treated surface. 30 of
96 toluene solution was applied so that the thickness after drying was 1 to 2 p1n, and then dried at room temperature to form adhesive layer B.

In this way, the stretched film of riiJ is pasted as the film-like base material B on the adhesive layer I3 side of the film-like base material A, which has the pressure-sensitive adhesive layer A on one side and the adhesive layer B on the other side, A heat-releasable pressure-sensitive adhesive sheet for masking was obtained.

This adhesive sort was cut to a size of 5 cm x 5 c7n as a sample sheet, and it was pasted on the center of the same steel plate as in Example 1, and then the paint was coated with a thickness of 10 μm and 71 cm in the same manner as in Example 1. It was applied so that Next, this steel plate was left in a hot air dryer at 10°C for 10 minutes to dry the paint, and the sample sheet almost completely peeled off and shrunk to envelop the paint in the center of the steel plate. The sheet could be removed by simply picking it up with your fingers. In addition, the masking effect at the sample tape attachment area in the center of the steel plate was sufficient.

The adhesive strength of the masking pressure-sensitive adhesive tape obtained in Example 2 to the steel plate was 45y/20m.
m width, and when heated at 85°C for 15 minutes, the heat shrinkage rate is 3% for film-like base material A in both the vertical and horizontal directions.
, 30% for film-like base material B.

Comparative Example 1 A pressure-sensitive adhesive sheet for masking was obtained in the same manner as in Example 1, except that an unstretched film with a thickness of 50μ7+1 made of soft polyvinyl chloride having the same composition as in Example 1 was used as the film-like group 11'B. Ta. The 1800 peel adhesion strength of this adhesive sheet to 5PC-grade bright steel plate is 70 F/
/20rnIn width.

When this adhesive sheet was adhered to a steel plate in the same manner as in Example 1, and paint was applied and dried, this adhesive sheet did not peel off at all. Therefore, an attempt was made to peel it off manually, but it took time to peel off the end portion, and although there was a masking effect, the efficiency of the peeling operation was extremely poor compared to Example 1.2.

Comparative Example 2 A pressure-sensitive adhesive sheet for masking was obtained in the same manner as in Example 2, except that the same unstretched film as in Comparative Example 1 was used as the film-like base material B. The 180° peel adhesion strength of this adhesive sheet to 5PC-grade flight steel plate is 45! 7
20m! It was n wide.

When the releasability of this adhesive sheet was examined in the same manner as in Example 1, it was found that this adhesive sheet did not peel off at all.
Although there was a masking effect, the peeling efficiency was extremely poor as in Comparative Example 1.

Patent applicant: Nitto Electric Industry Co., Ltd.

Claims (2)

[Claims] (1) This film-like base material A is attached to one side of the film-like base material A.
at least one having a heat shrinkage rate greater than the heat shrinkage rate of
A heat-shrinkable support in which a film-like base material B made of a seed film is laminated via an adhesive layer, and a pressure-sensitive adhesive layer provided on the film-like base material A side of this support. A sheet of heat-releasable masking pressure-sensitive adhesive tape made of Madara. (2) The film-like base material A is an unstretched plastic film, and the film-like base material B is a plastic film stretched in at least one direction.
Pressure-sensitive adhesive tape or sheet for masking as described in ). f3) Claim item (1) or (
Masking pressure-sensitive adhesive tape or sheet 1-8 described in section 2)