Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Compositions to be polymerized by wave energy wherein said...
Reexamination Certificate
1999-06-17
2001-03-27
Berman, Susan W. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Compositions to be polymerized by wave energy wherein said...
C522S084000, C522S085000, C522S086000, C522S031000, C522S059000, C522S099000, C522S113000, C522S148000, C522S172000
Reexamination Certificate
active
06207728
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a photo-curable composition and a photo-cured product thereof (hereinafter, also called cured product or cured film). Specifically, the present invention relates to a photo-curable composition which is excellent in storage stability and applicable to the surfaces of plastics, metals, ceramics, glass, wood, papers and the like having various shapes and which can give a photo-cured product excellent in weather-ability, heat resistance, transparency and scratch resistance, as well as a photo-cured product thereof.
Accordingly, the photo-curable composition and photo-cured product of the present invention are suitable for use in paints for metals, sizing agents for use in slate materials, hard coatings for plastic films, hard coatings for printing paper, stain-proof films for floor and wall tiles, hard coatings for optical lens, protective films for display elements, anti-reflective films, highly reflective films, selectively permeable films, fibrous coating reinforcing materials, resins for optical three-dimensional molding, optical lens, packaging compounds for semiconductors, insulating layers for semiconductors, adhesives for semiconductors, adhesives for optical products, printing plate materials, optical light-guide materials and optical switching materials.
2. Prior Art
As materials for forming the transparent cured film, thermosetting polysiloxane compositions are known and disclosed in Japanese Patent Application Laid-Open No. Sho 53-12952 and the like.
However, the cured films obtained from such thermosetting polysiloxane compositions, though being superior in weather-ability and scratch resistance, should be thermally treated at high temperatures for a long time, so there are problems that the productivity is low and the type of usable substrate is limited. Further, such thermosetting polysiloxane compositions have a problem that their performance becomes inferior during storage at normal temperatures, so they should be stored in a low-temperature state under the strict control of temperature.
On the other hand, as materials for forming the transparent cured film, photo-curable acrylic compositions which can be cured by using such rays as a UV light, are also known. Such photo-curable acrylic compositions are utilized in the field of hard coating and the like in various plastics because their curing rate is high and they can be cured at normal temperatures.
However, since the major components in the photo-curable compositions are an acrylic resin, there is a problem of low heat resistance and weather-ability as compared with the above-described thermosetting polysiloxane. In addition, since radical polymerization is utilized for the photo-curable acrylic compositions, there is a problem that inactivation of active radicals by oxygen in the atmosphere easily occurs so insufficient curing readily results. In particular, such insufficient curing easily occurs upon exposure to UV rays under the atmosphere.
Accordingly, photo-curable compositions having polymerizable groups such as a vinyl group, an epoxy group and the like introduced into silane compounds have been proposed for the purpose of improving weather-ability and scratch resistance. For example, U.S. Pat. No. 5,385,955 discloses a photo-curable composition comprising alkoxy silane having an epoxy group, a hydrolyzate of alkyl alkoxy silane, colloidal silica, and a photo-initiator.
However, there is a problem that such photo-curable compositions are sensitive to moisture while their photo-curing time (photo-curable property) is long. Accordingly, the insufficient curing easily occurs and there is a problem of unstableness in the characteristics of the resulting photo-cured products, such as heat resistance and weather-ability. On the other hand, if their photo-curable rate is raised, there is a problem that the storage stability of the photo-curable composition easily becomes poor.
Accordingly, Japanese Patent Application Laid-Open No. Hei 6-148895 discloses a photo-sensitive resin composition comprising: an alkali-soluble siloxane polymer obtained by hydrolysis in the presence of water and a catalyst and subsequent removal of the water and the catalyst by use of a hydrophobic organic solvent and a drying agent; a photo acid generator; and a solvent, and the hydroxyl group itself possessed by the siloxane polymer is utilized for photo-curable reaction.
However, when the hydrophobic organic solvent is merely used, water cannot be removed sufficiently from the photo-sensitive resin composition, and further the photo-sensitive resin composition does not contain a hydrating agent, so it is not possible to eliminate the influence of water or moisture from the outside or of water generated with time from the siloxane polymer.
OBJECT OF THE INVENTION
As described the above, the curing time of the conventional thermosetting polysiloxane compositions is long, and high-temperature heat treatment is required, so there are problems that applicable base materials are limited and storage stability is poor. On the other hand, the conventional photo-curable compositions comprising an acrylic type resin or a silicone type resin having polymerizable groups such as a vinyl group and an epoxy group respectively have the problems that they are poor in photo-curable property, and the resulting cured products are poor in weather-ability and heat resistance. Further, even the photo-sensitive resin composition disclosed in Japanese Patent Application Laid-Open No. Hei 6-148895 has a problem that it is poor in the photo-curable property and the storage stability, and the resulting photo-cured product is poor in the weather-ability and the heat resistance.
As a result of their eager study under these circumstances, the present inventors have found that the above problems can be solved by combination of a hydrolyzable silane compound, a photo acid generator, and a dehydrating agent. That is, the present inventors have found that by adding a dehydrating agent to a photo-curable composition, water contained in the photo-curable composition, water formed by self-condensation of the hydrolyzable silane compound, and water from the atmosphere at the time of coating are effectively removed whereby the photo-curable reaction of the photo-curable composition is significantly accelerated, and further the characteristics of the photo-curable composition can be maintained stably for a prolonged period of time.
Thus, the object of the present invention is to provide a photo-curable composition which has rapid photo-curable rate, and excellent in characteristics such as storage stability, heat resistance, weather-ability, scratch resistance and the like, and which is applicable to base materials with low heat resistance such as plastics, as well as a cured product including cured film obtained therefrom.
Another object of the present invention is to provide a photo-curing method for producing the a photo-cured product thereof.
SUMMARY OF THE INVENTION
The present invention relates to a photo-curable composition comprising the following components (A) to (C):
(A) both a hydrolyzable silane compound represented by the general formula (1) and a hydrolyzate or either of the two,
(R
1
)
p
Si(X)
4−p
(1)
wherein R
1
is a non-hydrolyzable organic group having 1 to 12 carbon atoms, X is a hydrolyzable group, and p is an integer of 0 to 3;
(B) photo acid generator; and
(C) dehydrating agent.
The photo-curable composition was constituted in this manner whereby the photo-curable reaction can be promoted and simultaneously storage stability and the like can be significantly improved. Further, such photo-curable composition can be subjected to pattern irradiation at normal temperatures without undergoing oxygen inhibition.
To constitute the photo-curable composition of the present invention, a hydrolyzable silane compound other than component (A) is preferably added, and specifically it is preferable to add the following components: a hydrolyzable silane comp
Sato Hozumi
Sekiguchi Manabu
Sugiyama Naoki
Berman Susan W.
JSR Corporation
Oblon, Spivak, McClelland,Maier & Neustadt, P.C.
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