Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Compositions to be polymerized by wave energy wherein said...
Reexamination Certificate
2001-07-03
2003-11-11
Seidleck, James J. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Compositions to be polymerized by wave energy wherein said...
C430S056000, C430S060000, C522S100000, C522S104000, C522S149000, C522S150000, C522S083000, C264S494000, C264S496000, C264S478000, C264S446000, C264S447000, C428S500000
Reexamination Certificate
active
06646022
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a photocuring resin composition giving a photocuring sheet having a superior appearance, decorativeness, abrasion resistance, chemical resistance, and weather resistance and free from surface tackiness, such photocuring sheets, a molded article using the same, and processes for production of the same.
2. Description of the Related Art
As methods for molding and simultaneously decorating the surface of a plastic product, various methods have been proposed such as (1) the method of giving a pattern to the inner surface of a mold in advance, (2) the method of attaching a transfer film to the inner wall of the mold and transferring the pattern etc. of the film to the outer surface of the molded article at the same time as molding, and (3) the method of adhering a function-imparting sheet or printed sheet to the inner wall of the mold and adhering that sheet to the surface of the molded article at the same time as molding. Regarding the methods of (2) and (3), Japanese Unexamined Patent Publication (Kokai) No. 60-250925, Japanese Examined Patent Publication (Kokoku) No. 59-36841, and Japanese Examined Patent Publication (Kokoku) No. 8-2550 propose the method of forming a weather resistant sheet or printed sheet to the inner wall of the mold, then injection molding a resin to produce a molded article with a surface covered by the sheet.
The above art, however, imparts decoration or functionality by transfer by a thermoplastic sheet or printing, so the surface hardness of the obtained molded article becomes insufficient. For example, when imparting weather resistance to a molded article, it is sufficient to use a high weather resistant sheet made of polyvinylidene fluoride (PVDF) etc., but there is the problem that a sufficient surface hardness cannot be obtained. As opposed to this, when trying to obtain a molded article having a high surface hardness, it has been necessary to use a pre-crosslinked sheet having a high surface hardness. This sheet, however, is difficult to use for molding a three-dimensional molded article.
Therefore, as disclosed in Japanese Examined Patent Publication (Kokoku) No. 7-323, a photocuring sheet obtained by laminating a photocuring resin layer formed by a resin composition including an acrylic resin, a compound having a reactive vinyl group, and a photopolymerization initiator with a sheet substrate has been proposed. With this method, however, the sheet before photocuring contains a low molecular weight compound having a reactive vinyl group, so the surface has tackiness, the tackiness of the surface changes along with time, and other phenomena occur or the storage stability in the roll state becomes poor. Specifically, there was the problem that it would stick and not unwind and, unless stored at a low temperature, the compound would seep out from the two ends. Further, due to the tackiness, trouble occurred in the printing process when used as a printed sheet.
To solve this problem, the inventors previously proposed a photocuring sheet free from tackiness by developing a substrate sheet obtained by laminating a composition comprised of an acrylic resin having an alicyclic epoxy group at its side chain and a photopolymerization initiator. They engaged in intensive studies aiming at achievement of a higher hardness and achievement of a better weather resistance and as a result discovered the present invention.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a photocuring resin composition giving a photocuring sheet superior in abrasion resistance, weather resistance, and chemical resistance and free of tackiness and therefore superior in processability and storage stability and therefore able to be used advantageously for the production of a fancily decorated molded article.
Another object of the present invention is to provide such a photocuring sheet and a process for production of the same.
Still another object of the present invention is to provide a molded article obtained using such a photocuring sheet and a process of production of the same.
According to a first aspect of the present invention, there is provided a photocuring resin composition comprising a thermoplastic resin (a-1) having a radical polymerizing unsaturated group at its side chain and a photopolymerization initiator (a-2) and substantially not comprising a crosslinking compound other than (a-1).
According to a second aspect of the present invention, there is provided a photocuring sheet comprising a substrate sheet (B) and any of the above photocuring resin compositions (A) laminated on the same.
According to a third aspect of the present invention, there is provided a process of production of a photocuring sheet comprising the steps of coating a mixed solution including a photocuring resin composition (A) and solvent on a substrate sheet (B) and heating the coated substrate sheet (B) to cause the solvent to vaporize, wherein the coated substrate sheet (B) is not heated continuously for 20 seconds or more to a temperature equal to or higher than a glass transition temperature of a resin ingredient (b) comprising a main ingredient of the substrate sheet (B).
According to a fourth aspect of the present invention, there is provided a photocuring decorative sheet including at least one of a printed layer and a deposited layer formed on a substrate sheet (B) side of any of the above photocuring sheets.
According to a fifth aspect of the present invention, there is provided a photocuring insert molding sheet comprising at least one of a printed layer and a deposited layer, and an adhesive layer formed on a substrate sheet (B) side of any of the above photocuring sheets.
According to a sixth aspect of the present invention, there is provided a photocuring insert molding sheet comprising at least one of a printed layer and a deposited layer, and an adhesive layer, and a primer sheet formed on a substrate sheet (B) side of any of the above photocuring sheets.
According to a seventh aspect of the present invention, there is provided a process of production of an insert molded article comprising the steps of inserting and arranging any of the above photocuring sheets, any of the above photocuring decorative sheets, or any of the above photocuring insert molding sheets so that the photocuring resin composition side faces the inner wall of a mold, closing the mold, injecting a molten resin into the mold, and allowing the resin to solidify to form a resin molded article with a photocuring sheet, photocuring decorative sheet, or photocuring insert molding sheet arranged on its surface, and irradiating light to photocure the photocuring resin composition on the surface of the molded article.
According to an eighth aspect of the present invention, there is provided a process of production of an insert molded article comprising the steps of inserting and arranging any of the above photocuring sheets, any of the above photocuring decorative sheets, or any of the above photocuring insert molding sheets so that the photocuring resin composition side faces the inner wall of a mold, preliminarily molding the photocuring sheet, photocuring decorative sheet, or photocuring insert molding sheet to make the sheet follow the shape of the mold, closing the mold, injecting a molten resin into the mold, and allowing the resin to solidify to form a resin molded article with a photocuring sheet, photocuring decorative sheet, or photocuring insert molding sheet arranged on its surface, and irradiating light to photocure the photocuring resin composition on the surface of the molded article.
According to a ninth aspect of the present invention, there is provided an insert molded article obtained by any of the above processes of production.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described in detail next.
The photocuring resin composition of the present invention includes a thermoplastic resin (a-1) having a radical polymerizing unsaturated group a
Kakuno Yoko
Okazaki Shougo
Suemura Kenji
Watanabe Hiroyuki
McClendon Sanza L.
Mitsubishi Rayon Co. Ltd.
Seidleck James J.
LandOfFree
Photocuring resin compositions, photocuring sheets and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Photocuring resin compositions, photocuring sheets and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photocuring resin compositions, photocuring sheets and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3142254