JPH05263052A - Self-adhesive composition and self-adhesive tape - Google Patents

Abstract

PURPOSE:To provide a self-adhesive compsn. which gives the subject tape capable of being unwound by a decreased force without detriment to the self-adhesive properties by compounding a specific rubber component with a specified amt. of a tackifying resin. CONSTITUTION:100 pts.wt. rubber component comprising a natural rubber and a styrene-isoprene-styrene block copolymer is compounded with 90-130 pts.wt. tackifying resin (e.g. Arkon P70, a product of Arakawa Chemical Industry, Co., Ltd.). The figure shows a cross section of the object tape prepd. by forming this self-adhesive layer 2 on one side of a substrate 1 and a release layer 11 on the other side.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an adhesive composition and an adhesive tape.

[0002]

2. Description of the Related Art Conventionally, an adhesive tape having a rubber-based adhesive layer provided on one surface of a support has been widely used for packaging because it has excellent adhesiveness in a wide environment of use and temperature range.
A rubber-based pressure-sensitive adhesive is usually composed of rubber and a tackifier resin, a softening agent, a filler, an antiaging agent, and the like. Natural rubber has excellent adhesiveness and high cohesive strength. Since the rewinding force is large and the workability of pulling out the adhesive tape from the roll is poor at the time of sticking work, a long-chain alkyl group-containing polymer or silicon compound is applied to the back surface of the support as a release agent. There is. Further, a long-chain alkyl group-containing polymer or a softening agent such as lanolin is also added to the pressure-sensitive adhesive.

[0003]

However, the long-chain alkyl group-containing polymer is relatively inexpensive and easy to apply to the support, but the releasability is not sufficient, and a large amount is used to improve the releasability. When used as a roll, there is a problem that the release agent migrates to the pressure-sensitive adhesive layer when it is stored and transported as a roll, and the pressure-sensitive adhesive force is significantly reduced. Further, the silicon compound has excellent releasability, but is relatively expensive, coating is relatively difficult, and a cross-linking curing step after coating is required. Further, there has been a problem that when a release agent or a softening agent is added to the pressure-sensitive adhesive, the pressure-sensitive adhesive strength is significantly reduced.

An object of the present invention is to provide a pressure-sensitive adhesive composition and a pressure-sensitive adhesive tape which can solve the above-mentioned conventional problems and reduce the rewinding force without lowering the pressure-sensitive adhesive performance.

[0005]

According to the invention of claim 1, 90 to 130 parts by weight of a tackifying resin is added to 100 parts by weight of a rubber component composed of natural rubber and styrene-isoprene-styrene block copolymer (SIS). Is added.

The invention of claim 2 is characterized in that the pressure-sensitive adhesive layer made of the above-mentioned pressure-sensitive adhesive composition is formed on one surface of the support, and the release agent layer is provided on the other surface. Is.

The natural rubber used in the present invention is not particularly limited as long as it is generally used in a pressure-sensitive adhesive composition, and may be any of pale crepe, ribbed smoked sheet and the like. Further, mastication may or may not be carried out, and those having different mastication levels may be mixed. The tackifying resin used in the present invention is not particularly limited as long as it is generally used in a pressure sensitive adhesive composition, a rosin resin, a terpene resin,
Aromatic petroleum resins, coumarone / indene resins, phenolic resins, xylene resins and the like can be mentioned. The content of styrene-isoprene-styrene block copolymer (SIS) is preferably 15 to 50 parts by weight based on 100 parts by weight of natural rubber. If it is less than 15 parts by weight, sufficient cohesive force cannot be obtained, and if it exceeds 50 parts by weight, the elastic modulus becomes too high,
This is because the initial tackiness is reduced. The addition amount of the tackifying resin is set to 90 to 130 parts by weight with respect to 100 parts by weight of the rubber component.If it is less than 90 parts by weight, sufficient adhesive force cannot be obtained, and if it exceeds 130 parts by weight, This is because the initial tackiness is reduced. More preferably, it is 95 to 125 parts by weight.

[0008]

The pressure-sensitive adhesive composition of the present invention comprises natural rubber and styrene-
A tackifier resin for 100 parts by weight of a rubber component composed of isoprene-styrene block copolymer (SIS)
Since 90 to 130 parts by weight is added, the styrene phase separated from the rubber phase forms domains, increasing the cohesive force, and rewinding power while minimizing the impact on cost and adhesive performance. Can be reduced.

In the pressure-sensitive adhesive tape of the present invention, a pressure-sensitive adhesive layer comprising the above-mentioned pressure-sensitive adhesive composition is formed on one surface of a support,
Since the release agent layer is provided on the other surface, it is possible to improve the workability of pulling out the adhesive tape from the roll body during the attaching work while minimizing the influence on the cost and the adhesive performance.

[0010]

EXAMPLES Examples of the present invention will be specifically described below.
The invention is not limited to the examples. Example Natural rubber prepared by mastication to adjust the Mooney viscosity to 95 (rubber standard SMR pale crepe X1 in Malaysia)
50 parts by weight, natural rubber adjusted to Mooney viscosity of 75 (SMR
Pale crepe X1) 50 parts by weight, styrene-isoprene-styrene block copolymer ("TR" manufactured by Shell Chemical Co., Ltd.
1107 ") and 40 parts by weight of tackifying resin (Arakawa Chemical Industries, Ltd." Alcon P70 ") 170 parts by weight of a mixture of toluene 5
It was dissolved in 00 parts by weight to prepare an adhesive composition.

The resulting adhesive composition was coated on one side with a 0.5% solution of a long-chain alkyl group-containing polymer ("Peeloyl" manufactured by Yushisha Kogyo Co., Ltd.) as a release agent to give a weight of 5 g / m after drying.
^The thickness where the release agent layer 11 is formed by coating and drying so as to be ^2.
Support 1 made of 60 μm stretched polypropylene film
The release agent layer 11 was coated on one side thereof with a thickness of 25 μm and a weight after drying of 75 g / m ^2, and dried to provide the pressure-sensitive adhesive layer 2 to obtain a pressure-sensitive adhesive tape.

The obtained adhesive tape is wound around a paper tube and heated at 70 ° C.
After aging for 24 hours, the low speed rewinding force from the roll, the SP adhesive force, and the tack were measured. These adhesive properties are measured by JI
It carried out based on S-Z-0237. The results are as shown in Table 1.

Comparative Example Natural rubber (S of Mooney viscosity adjusted to 95)
50 parts by weight of MR pale crepe X1), 50 parts by weight of natural rubber adjusted to Mooney viscosity of 75 (SMR pale crepe X1), tackifying resin ("Arcon P7 manufactured by Arakawa Chemical Industry Co., Ltd."
0 ") Example 1 except that 120 parts by weight of the mixture was used.
In the same manner as above, an adhesive tape roll was obtained and the physical properties were measured. The results are as shown in Table 1.

[0014]

[Table 1] As described above, in the example, the rewinding force could be significantly reduced while the adhesive property was rather higher than that of the comparative example.

[0015]

EFFECT OF THE INVENTION Since the adhesive composition and the adhesive tape of the present invention are constructed as described above, the rewinding force can be reduced with almost no influence on the adhesive performance and cost, and it can be used by women and elderly people. Improves the workability of packaging work that is often carried out by workers.

[Brief description of drawings]

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

[Explanation of symbols]

 1 Support 2 Adhesive Layer 11 Release Agent Layer

Claims (2)

[Claims] 1. A rubber component comprising natural rubber and styrene-isoprene-styrene block copolymer (SIS).
A pressure-sensitive adhesive composition, wherein 90 to 130 parts by weight of a tackifying resin is added to 100 parts by weight. 2. A pressure-sensitive adhesive tape comprising a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to claim 1 formed on one surface of a support and a release agent layer provided on the other surface.