(19) Japanese Patent Office (JP)			(12) Publication of Unexamined Patent Application (A)				(11) Disclosure Number: Hei 08-225775 (43) Date of Disclosure: 1996.09.03
(51) Int. Cl.6   C09J 7/02		Identification Code JJX JHU JJY JKE JKK			Internal Agency Classification No. C09J 7/02	Indication of Technical Field   JJX JHU JJY JKE JKK
	Examination Request Status: Not yet requested. No. of Claims: 10 (12 pages total)
				(21) Filing Number: Hei 07-294987 (22) Date of Application: 1995.10.19 (32) Priority Date: 1994.10.20 (33) Priority Country:  Japan (JP)
(71)  Assignee:          000004592                                     Nippon Carbide Industries Co., Inc.                                     3-1 Marunouchi 3-chome                                     Chiyoda-ku, Tokyo-to (71)  Assignee:          000102980                                     Lintec Corporation                                     23-23 Hon-cho                                     Itabashi-ku, Tokyo-to (72)  Inventor:              Yoshikuni TOBIYO                                     1134 Kawaberi                                     Uotsu-shi, Fukuyama-ken (72)  Inventor:              Yoshiyasu TAKEDA                                     1-9-11 Shinkanaya                                     Uotsu-shi, Fukuyama-ken

Specifications

 

(54) [Title of the Invention]   Surface Protective Film

 

(57) Summary

[Goal]  The goal of this invention is to provide a new type of surface protective film. This film may be uniformly attached to various types of objects at normal temperatures and pressures Furthermore, after use the film is easily removed and readily incinerated. This surface protective film is advantageous for preventing product rejects.

 

[Content of the Invention]  This invention relates to a masking film that consists of at least a base film layer and an adhesive layer. The major component of said base film layer is a polyolefin-type resin. The major component of the adhesive layer is a hydrogenated (A) - (B) block polymer, where said (A) block is a copolymer consisting of less than 20 wt% of a vinyl aromatic compound, and where said (B) block is a copolymer consisting of conjugated diene plus greater than 80 wt% of a vinyl aromatic compound.

 

[Scope of the Patent Claims]

[Claim 1] A masking film comprising at least a base film layer and an adhesive layer; said masking film being characterized in that the major component of said base film layer is a polyolefin-type resin; the major component of the adhesive layer is a hydrogenated (A) - (B) block polymer; said (A) block is a copolymer consisting of less than 20 wt% of a vinyl aromatic compound; and said (B) block is a copolymer consisting of conjugated diene plus greater than 80 wt% of a vinyl aromatic compound.

 

[Claim 2] A masking film per Claim 1, wherein the hydrogenated (A) - (B) block copolymer (B) block vinyl aromatic / conjugated diene mass ratio is [1 to 30] / [99 - 70], and at least 70% of the double bonds within said (B) block conjugated diene component have undergone hydrogenation.

 

[Claim 3] A masking film per Claim 1, wherein said polyolefin-type resin comprises at least one of the following: ultra low density polyethylene, linear low density polyethylene, low density polyethylene, high density polyethylene, polypropylene, and polybutene-1.

 

[Claim 4] A masking film per any one of Claims 1 through 3, wherein said base film layer contains an anti-blocking agent.

 

[Claim 5] A masking film per any one of Claims 1 through 4, wherein said adhesive layer contains a tackifier.

 

[Claim 6] A masking film per Claim 5, wherein said anti-blocking agent is an amide-type anti-blocking agent. [TRANSLATOR'S NOTE: This referral to Claim 5 is probably an error. This probably was supposed to refer to Claim 4, since Claim 4 is the superior claim that mentions an anti-blocking agent.]

 

[Claim 7] A masking film per any one of Claims 1 through 6, wherein at least one layer, either the base film or the adhesive layer,  contains an ultraviolet light absorbent.

 

[Claim 8] A masking film per any one of Claims 1 through 7, wherein elongation set of said masking film is less that 30%.

 

[Claim 9] A masking film per any one of Claims 1 through 8, wherein a parting agent is provided upon the base film surface layer, wherein said parting agent does not contact the adhesive layer.

 

[Claim 10] A masking film per any one of Claims 1 through 9, wherein said masking film is formed by coextrusion of said base film layer and said adhesive layer.