JPS63142086A - Tacky adhesive tape - Google Patents

Abstract

PURPOSE:To obtain a tacky adhesive tape having excellent stress-relaxation capability and suitable for sealing or medical use, etc., by applying an easily stretchable part longitudinally at the center of a supporting substrate having a tacky adhesive layer and making the thickness of the middle part of said stretchable part thinner than that of the edges of the part. CONSTITUTION:A supporting substrate 1 has an easily stretchable part 12 at the center of the width of the substrate. Parts having low stretchability 11 are formed at both edges of the stretchable part 11 and the middle part 12b of the width of the stretchable part 12 is made to be thinner than the edge parts 12a of the stretchable part 12. The objective tacky adhesive tape can be produced by applying a tacky adhesive layer 2 on one or both surfaces of the part 11 having low stretchability.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention uses a support base material having a thin, easily stretchable part at the center in the width direction. The present invention relates to an adhesive tape that has a stress relaxation ability and is suitable for sealing, medical use, etc.

Prior to the conventional technology, members of the group to which the present inventors belong have developed a support base material with a composite structure that has an easily stretchable part in the center in the width direction and non-stretchable parts on both sides. (Patent Application No. 231406 of 1983)
.

This reduces the shear stress at the adhesive interface, etc., reduces the required adhesive area, makes the adhesive layer thinner and patterned (partial application), makes the adhesive tape lighter, and improves the reliability of sealing, etc. This makes it possible to improve the efficiency of sealing work, reduce sealing errors, etc. Therefore,
Until now, adhesive tapes made of support base materials with low elasticity such as kraft paper, plastic films, or woven fabrics had weak adhesive properties such as paper. Problems with the reliability of the seal, such as the phenomenon where the surface layer tears and the seal comes undone, the phenomenon where the adhesive layer and the adherend peel off naturally when the adhesive force is low, or the entire structure is based on a 5-elastic support base. This overcomes the problems associated with adhesive tapes made from materials such as difficulty in handling due to stretching of the tape when unwinding a rolling object, and peeling due to stress when stretched and pasted.

Problems to be Solved by the Invention A pressure-sensitive adhesive tape using a support base material having an easily stretchable portion has the advantage that it can be stretched and attached in addition to stress relaxation properties based on the easily stretchable portion.

The present inventors focused on its stretchable adhesion properties and used it in applications where stretching is advantageous, such as before cutting, and found that it broke when stretched to a large extent, and that both ends of the easily stretchable portion 12 If wrinkles occur on 12a (see Figure 2), which impairs the adhesion work, or the adhesion area to the adherend decreases due to floating or air bubbles, and this is combined with the shrinkage force of the easily stretchable part, it may peel off. I found out something.

Means for Solving the Problems The present invention overcomes the above-mentioned weaknesses by making the center part in the width direction of the easily stretchable part of the support base material thin, and the support base material is made of a support base material having a easily stretchable part. This is a more universal adhesive tape.

That is, the present invention provides an adhesive tape having a pressure-sensitive adhesive layer on one or both sides of a supporting base material, in which the supporting base material has an easily stretchable part in the center part in the width direction, and the easily stretchable part has a central part in the easily stretchable part. To provide an adhesive tape characterized in that the thickness of the adhesive tape is thinner than the thickness of the end portion thereof.

Function: By using a support base material for the adhesive tape, which has a thin center part and easily stretchable part in the center part in the width direction,
Based on the stress relaxation ability of the easily stretchable part (in addition to the thinner central part, it is also possible to alleviate stress concentration at or near the joint between the easily stretchable part and other parts). This prevents or suppresses the occurrence of breaks and wrinkles in the area.

Example Embodiments of the present invention are shown in FIGS. 1a to 1d.

The adhesive tape of the example includes a supporting base material 1 having a non-stretchable part 11 at both ends of an easily stretchable part 12 at the center in the width direction, and one or both sides of the non-stretchable part 11. It is made of a material having an adhesive layer 2 on it. Further, in the easily stretchable portion 12, the center portion 12b in the width direction is the end portion 12a.
Thinner than (formed.

In addition, 3 is a releasable treated layer provided corresponding to the adhesive layer 2 in order to facilitate unwinding in the case of a rolled product, and this may be provided partially (as necessary). Provided accordingly.

The adhesive tape of the present invention has an adhesive layer provided on one or both sides of a supporting base material having a thin and easily stretchable part in the center in the width direction. There are no particular limitations on other aspects such as the form.

The easily stretchable part may have a thinner central portion as long as it prevents or suppresses stress from concentrating at or near the joint between the easily stretchable part and other parts. Therefore, there are no particular limitations on the method or form of thinning the central portion.

The thickness of the center part in the width direction of the easily stretchable part is suitably 10 to 75% of the thickness at the ends of the easily stretchable part or the parts other than the 5 stretchable part of the supporting base material, preferably 2.
It is 0-40%. If the thickness is too thin, it may break at that part.

The thickness of the supporting base material is generally 1OμIIl to 1■, but is not limited thereto.

Easily stretchable materials that can be used in the present invention include, for example, nonwoven fabrics made of urethane fibers (spandex (trade name)), stretchable knitted or woven fabrics such as rubber knitting, polyurethane-based materials, polyolefin-based materials, Representative examples include elastomers such as polyester and polystyrene, and synthetic resins such as soft vinyl chloride.

Examples of materials that are not highly elastic include materials that are used as supporting base materials in conventional adhesive tapes, such as kraft paper, common plastic films, and cloth.

On the other hand, there are no particular limitations on the adhesive constituting the adhesive layer, and known adhesives such as acrylic adhesives, rubber adhesives, styrene/isobutylene block polymer adhesives, etc. may be used. The thickness of the adhesive layer is 5 to 5
00 um is common, but is not limited to this.

Example 1 There is a melt index (hereinafter abbreviated as MI) in the center.

) is 0.5 g/10 minutes (230°C), and MI is 1.5 g/1 at both ends.
Extrude polypropylene at 230℃ for 170~
The end thickness was 200 um obtained by molding at 200°C.

An adhesive layer (thickness: 501 rm) made of a styrene-based hot melt adhesive was provided on one side of a polypropylene portion of a supporting base material having a width of 60 mm to obtain an adhesive tape.

The easily stretchable part (ethylene-propylene elastomer part) has a width of 20 mm, and the thickness gradually decreases toward the center (see Figure 1 a), and the thickness at the center is 160 μm.
It is.

Example 2 An adhesive tape was obtained in accordance with Example 1, except that the supporting base material had a central thickness of 140 μm in the easily stretchable portion.

Example 3 An adhesive tape was obtained in accordance with Example 1, except that the supporting base material had a central thickness of 120 μm in the easily stretchable portion.

Comparative Example 1 An adhesive tape was obtained in the same manner as in Example 1, except that the thickness of the easily stretchable portion was set to 200 μI, so that the supporting base material had a uniform thickness as a whole.

Comparative Example 2 An adhesive tape was obtained in the same manner as in Example 1, except that the easily stretchable portion had a supporting base material of 230 pm in thickness.

Both ends of the adhesive tapes obtained in Evaluation Test Examples and Comparative Examples were cut to prepare sample tapes with a width of 30 mm, and the samples were subjected to the following tests.

[Breaking strength 1: In order to break the sample tape at the joint between the easily stretchable part and other parts, the chuck spacing was 20 nu++, and the tensile speed was 300.
The maximum stress up to rupture was measured under conditions of TMA 7 minutes.

[Adhesive Strength 1] After stretching the sample tape by 150% or 300% in the width direction and pressing it onto a stainless steel plate with a 1 kg roller, the shear adhesive strength was immediately measured at a speed of 300 m+a for 7 minutes.

[Holding Force] A sample tape was stretched by 150% or 300% in the width direction and pressed onto a stainless steel plate using a 1 kg roller, and the time until it peeled off naturally was measured, and this was taken as the holding force.

[Adhesion workability 1: The workability when the sample tape was stretched by 150% or 300% in the width direction and pasted onto a stainless steel plate by hand was evaluated as excellent, good, or good.
Sensory evaluation was performed on a three-point scale of fair. Note that a rating of "fair" is given when wrinkles occur.

The results are shown in the table.

From the table, it can be seen that the adhesive tape of the present invention has excellent stress relaxation properties, and is excellent in breaking strength, adhesive strength in a stretched state, reliability of sealing, and workability in pasting.

Therefore, the adhesive tape of the present invention is useful not only for sealing and packaging, but also for medical purposes such as before distribution, for tightening, fixing, and bundling, and as a hinge, etc., and has excellent universality. have.

Effects of the Invention Since the adhesive tape of the present invention uses a support base material having a thin centrally-thick easily stretchable part in the center in the width direction, stress concentration at the joint between the easily stretchable part and other parts is reduced. It has excellent relaxation properties, excellent adhesive properties in the case of stretch bonding, and has excellent practical value such as universal applicability.

[Brief explanation of the drawing]

Figures 1a, b, c, and d are sectional views of other embodiments, respectively;
FIG. 2 is an explanatory diagram of the state in which wrinkles occur. 1; Supporting base material 11: Portion that is not stretchable 12: Easily stretchable portion 12a: End portion 12b of the easily stretchable portion: Central portion of the easily stretchable portion 2: Adhesive layer 3: Peelable treated layer Patent Applicant Nitto Electric Industry Co., Ltd. Agent Tsutomu Fujimoto Figure 1 b CΔ Figure 2

Claims (1)

[Claims] 1. In an adhesive tape having an adhesive layer on one or both sides of the support base material, the support base material has an easily stretchable part in the center part in the width direction, and the thickness of the center part of the easily stretchable part is that Adhesive tape that is thinner than the edge.