JPH07316528A - Water dispersion type tacky agent composition and tacky sheet or tape using the same composition - Google Patents

Abstract

PURPOSE:To obtain a water dispersion type tacky agent composition capable of improving surface resistivity without lowering tacky characteristics and available also for electrical insulation uses by adding casein to a tacky agent at a specific ratio. CONSTITUTION:This composition contains (A) 100 pts.wt. of a tacky agent and (B) 0.2-20 pts.wt. of casein. Furthermore, the composition is preferably used as a tacky sheet having a tacky agent layer consisting of the composition on a substrate such as vinyl chloride and e.g. an acrylic tacky agent is preferably used as the component A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-dispersed pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet or tape using the same, and particularly to a water-dispersed pressure-sensitive adhesive composition for electrical insulation and pressure-sensitive adhesive using the same. Regarding sheet or tape.

[0002]

2. Description of the Related Art Conventionally, adhesive sheets or tapes for electrical insulation (hereinafter, the adhesive sheets or tapes are collectively referred to as adhesive tapes) are based on vinyl chloride (PVC), polyethylene terephthalate (PET), polyethylene and the like. There are materials that can be used according to the purpose, performance, price, etc. In recent years, environmental issues have come to be emphasized, and from the viewpoint of work environment and fire risk, adhesives have been desolvated, specifically, they are being converted to water-dispersed systems and hot-melt systems. Yes, some have been put to practical use. However, the one using the water-dispersed pressure-sensitive adhesive has a drawback that a surface active agent in the pressure-sensitive adhesive inevitably lowers the surface resistivity and causes dielectric breakdown through the pressure-sensitive adhesive surface. Therefore, it cannot be used for electrical insulation at present.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a water-dispersed pressure-sensitive adhesive composition which has improved surface resistance characteristics, which have been a drawback of conventional water-dispersed pressure-sensitive adhesives, and can be used in electrical insulation applications. And to provide an adhesive tape using the same.

[0004]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that a water-dispersed PSA composition containing casein can improve the surface resistivity without lowering the adhesive properties. The inventors have found that it can be improved, and have completed the present invention. That is, the present invention provides (1) adhesive 10
A water-dispersed PSA composition containing 0.2 to 20 parts by weight of casein relative to 0 parts by weight, (2) a base material, and (1)
A pressure-sensitive adhesive sheet or tape having a pressure-sensitive adhesive layer made of the water-dispersed pressure-sensitive adhesive composition described above, (3) the base material is vinyl chloride
(2) The pressure-sensitive adhesive sheet or tape as described above.

The pressure-sensitive adhesive is not particularly limited as long as it can be used as a water-dispersed pressure-sensitive adhesive, but it functions as a pressure-sensitive adhesive for adhering target adhesive objects to each other. is there. Examples thereof include natural rubber, synthetic rubber, a mixture thereof, or an acrylic adhesive. Among them, cyclized rubber, chloroprene rubber, butyl rubber, ethylene / vinyl acetate copolymer, polyacrylic acid or polymethacrylic acid-based resin, etc. can be used properly depending on the application in terms of electrical insulation, water resistance, weather resistance, etc. ing.
Acrylic polyacrylic acid and polymethacrylic acid resins include not only the main monomers such as ethyl acrylate, butyl acrylate, ethyl methacrylate and butyl methacrylate, but also vinyl acetate, acrylonitrile, and acrylic as comonomers. Amide, styrene, acrylic acid, methacrylic acid, etc. can be used. Further, these pressure-sensitive adhesives may be blended with known additives such as tackifiers, antioxidants, fillers and pigments, if necessary.

[0006] Casein is a kind of protein obtained from milk, soybean, etc., but milk casein is preferable because of its price and availability. Further, any of acid casein, lactic acid casein, rennet casein and the like which are usually commercially available may be used. The amount of casein used (solid content) is 0.2 to 20 parts by weight, preferably 0.5 to 10 parts by weight, and more preferably 1 to 5 parts by weight, based on 100 parts by weight of the adhesive. This is because when the amount of casein used is less than 0.2 parts by weight, the surface resistivity does not improve, and when it exceeds 20 parts by weight, the adhesive properties deteriorate.

In the water-dispersible pressure-sensitive adhesive composition of the present invention, in addition to the above-mentioned pressure-sensitive adhesive and casein, an emulsifier (eg, nonionic, anionic, cationic, amphoteric surfactant, etc.) may be added, if necessary. A tackifier (for example, a terpene resin, a petroleum resin, a rosin resin), a modified compound thereof, or the like can be added.

The water-dispersible pressure-sensitive adhesive composition of the present invention is prepared by making casein into an aqueous solution, adding this to the pressure-sensitive adhesive and mixing them. The pressure-sensitive adhesive tape of the present invention comprises a base material and a pressure-sensitive adhesive layer formed on the base material and comprising the water-dispersed pressure-sensitive adhesive composition. The formation of the layer of the composition on the substrate is performed by a means known per se. The substrate is not particularly limited as long as it is a commonly used substrate. For example, PV
C, PET, polyethylene, kraft, acetate cloth, glass cloth, crepe paper, etc. are inexpensive, and 3
PVC and polyethylene are preferable from the viewpoint of following curved surface and versatility. The film thickness of the base material depends on its application,
50 to 500 from the viewpoint of cubic curved surface tracking and electrical insulation
μm is preferable, and more preferably 100 to 400 μm. Although the film thickness of the water-dispersed pressure-sensitive adhesive varies depending on its use, it is preferably 5 to 200 μm, more preferably 10 to 50 μm from the viewpoint of adhesiveness. The production of the pressure-sensitive adhesive tape is not particularly limited and may be carried out by a conventional method. For example, after the pressure-sensitive adhesive is applied to the base material, heat drying is performed and the tape is wound into a regular length to manufacture the tape.

[0009]

EXAMPLES Next, the present invention will be specifically described by way of examples, but the present invention is not limited to these.

Example 1 As a tackifier, 100 parts by weight of a terpene resin (Ys-Hara Chemical Co., Ys resin Px1000) was dissolved in 67 parts by weight of toluene. To this, 5 parts by weight of an emulsifier (Emulgen 920, manufactured by Kao Corporation) was added and mixed uniformly. Thereafter, 133 parts by weight of distilled water was added to this mixed solution to obtain a resin emulsion. Casein (dairy, Wako Pure Chemical Industries)
An aqueous casein solution was obtained by dissolving 100 parts by weight of 900% by weight of 0.5% aqueous ammonia. Natural rubber latex as an adhesive (Soctex C, manufactured by Socfin)
80 parts by weight of the above resin emulsion was uniformly mixed with 100 parts by weight of B). To this, 8 parts by weight (solid content) of the casein aqueous solution was added to obtain a water-dispersed PSA composition. This water-dispersed pressure-sensitive adhesive composition was uniformly applied onto a PET film having a thickness of 38 μm so as to have a dry thickness of 30 μm using an applicator to obtain a pressure-sensitive adhesive tape.

Example 2 Acrylic adhesive (SE-2500 manufactured by Showa High Polymer Co., Ltd.)
To 100 parts by weight of the casein solution used in Example 1 was added 5 parts.
Parts by weight (solid content) were added to obtain a water-dispersed PSA composition. An adhesive tape was obtained in the same manner as in Example 1.

Example 3 Instead of a PET film having a thickness of 38 μm, a thickness of 150 was used.
μm PVC film (polymerization degree 1000, plasticizer / dioctyl phthalate 50 parts by weight / PVC 100 parts by weight)
An adhesive tape was obtained in the same manner as in Example 1 except that was used.

Comparative Example 1 100 parts by weight of masticated natural rubber (RSS-1) and tackifier (Ys Resin Px, manufactured by Yasuhara Chemical Co., Ltd.)
80 parts by weight of 1000) was dissolved in 420 parts by weight of toluene to obtain an adhesive. An adhesive tape was obtained in the same manner as in Example 1.

Comparative Example 2 An adhesive tape was obtained in the same manner as in Example 1 except that the casein aqueous solution was not added.

Comparative Example 3 An adhesive tape was obtained in the same manner as in Example 2 except that the casein aqueous solution was not added.

Using the adhesive tapes obtained in Examples 1 to 3 and Comparative Examples 1 to 3, the surface resistivity, tack (J.DOW) and adhesive strength of these adhesive tapes were measured. The surface resistivity, tack (J ・ DOW) and adhesive strength (peeling adhesive strength) are measured according to JIS K
6911, JIS Z 0237 and JIS Z02
37. The results are shown in Table 1.

[0017]

[Table 1]

From the results shown in Table 1, the surface resistivity of the example was better than that of the comparative examples 2 and 3 in which the casein aqueous solution was not added. Further, the tack and the adhesive strength are maintained at the same values as those without addition of the casein aqueous solution. Furthermore, the water-dispersed pressure-sensitive adhesive composition of the present invention has the same surface resistivity, tack and adhesive strength as those of Comparative Example 1 using a conventional solvent-type, non-aqueous pressure-sensitive adhesive, which is a drawback of the solvent-type pressure-sensitive adhesive. There is no concern about the poor working environment or the risk of fire.

[0019]

INDUSTRIAL APPLICABILITY As described above, the water-dispersed PSA composition of the present invention, in which casein is added to the PSA, can improve the surface resistivity without lowering the adhesive property. Therefore, the water-dispersed pressure-sensitive adhesive composition and the pressure-sensitive adhesive tape using the water-dispersed pressure-sensitive adhesive composition can also be used for electrical insulation applications which have been difficult to use in the past.

Continued Front Page (72) Inventor Akira Morioka 1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation

Claims (3)

[Claims] 1. The amount of 0.2 to 100 parts by weight of the adhesive.
A water-dispersed PSA composition containing 20 parts by weight of casein. 2. A pressure-sensitive adhesive sheet or tape having a base material and a pressure-sensitive adhesive layer comprising the water-dispersed pressure-sensitive adhesive composition according to claim 1. 3. The pressure-sensitive adhesive sheet or tape according to claim 2, wherein the base material is vinyl chloride.