Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
1999-04-12
2001-06-12
Crispino, Richard (Department: 1734)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C156S212000, C156S245000, C156S273700, C427S146000, C428S515000, C264S135000, C264S259000, C264S548000
Reexamination Certificate
active
06245182
ABSTRACT:
This application is a 371 application of International Application No. PCT/JP98/03531 filed Aug. 7, 1998.
TECHNICAL FIELD
The present invention relates to a transfer material and surface protecting sheet which can provide a molded article excellent in abrasion resistance and chemical resistance without causing crack in curved part of the molded article, and to a method for producing a molded article excellent in abrasion resistance and chemical resistance by using the same. The present invention can make possible not to remain fluidity and stickiness on a protecting printed layer prior to irradiation with an active energy ray, even in an inline printing process.
PRIOR ART
As a method for producing a molded article excellent in abrasion resistance and chemical resistance, there are conventionally a method in which a transfer material obtained by providing a protecting printed layer composed of an active energy ray curable resin composition, on one releasing surface of a substrate sheet, and providing an additional layer such as a picture printed layer, an adhesive printed layer and the like, on the protecting printed layer, is adhered on a surface of a molded article, and the substrate sheet is released; or a method in which a surface protecting sheet obtained by providing a protecting printed layer composed of an active energy ray curable resin composition, on one no-releasing surface of a substrate sheet, and providing an additional layer such as a picture printed layer, an adhesive printed layer and the like, on the opposite surface of the substrate sheet, is adhered on the surface of a molded article, and the like.
However, in the method for producing a molded article excellent in abrasion resistance and chemical resistance, if an active energy ray curable resin composition of the sheet material such as a transfer material and a surface protecting sheet, is crosslinked and cured (pre-cured) by irradiation with an active energy ray prior to use, cracks easily occur in a protecting printed layer situated curved part of the molded article on adhering the sheet material to the molded article.
On the other hand, if irradiation with an active energy ray is not conducted in producing a sheet material but is conducted after adhesion of the sheet material to the molded article (after-cure), occurrence of crack in the protecting printed layer can be prevented, however, the following problems occur in the protecting printed layer prior to irradiation with an active energy ray.
In general, for forming various printed layers continuously on a sheet, a conventional multi-colour rotogravure printing machine as shown in FIG.
9
and the like are used. Main flow in such a machine is as follows: A sheet to be printed is continuously fed out from winding off part
15
, then, first, in the first printing unit of multi-colour rotogravure printing part
16
, the sheet is passed between rotary plate cylinder
18
the surface on which ink being supplied from ink pan
19
, and impression cylinder
20
which applies pressure to the plate cylinder
18
, and the ink is transferred on the sheet to form a printed layer. The sheet subsequently is passed through drying part
22
which comprises a steam drum, hot wind, cold wind, and/or the like to dry the printed layer. The sheet is then carried to the next printing unit, and another printed layer is formed on the sheet in the same manner as in the above-described printing unit. The above described procedure is repeated several times with optionally changing the surface on which the printed layer is formed, and the sheet is wound up at a winding up part
17
after all the printed layers are formed. In this machine, tension of the sheet may be properly controlled at the location of guide rolls
21
.
A printed layer such as a picture printed layer, adhesive printed layer, and the like, generally loses fluidity and stickiness when it passes through the drying part
22
of the printing units. However, a protecting printed layer composed of a conventional active energy ray curable resin composition keeps fluidity and stickiness after such degree of drying. The reason for this is that the above-described drying part
22
has a length as short as 2 m, and the heating temperature thereof is low. Further reason is that the passing speed of the sheet through the drying part
22
is fixed based on printing speed of the printed layer, for example, a printing speed of 40 m/minute, and the period during which the protecting printed layer is heated in the drying part
22
is as short as about 3 seconds.
As a result, in the case of preparing a transfer material, the ink for forming a protecting printed layer once transferred on a substrate sheet may move to a guide roll
21
of the printing machine, or the ink for forming a picture printed layer, or for forming a adhesive printed layer and the like, may not be successfully transferred on a protecting printed layer by plate cylinder
18
, and the ink for forming a protecting printed layer once transferred on a substrate sheet may be reversely transferred to the plate cylinder
18
which forms the picture printed layer, adhesive printed layer and the like. That is, what is called back trap may occur.
In the case of preparing a surface protecting sheet, likewise, the ink for forming a protecting printed layer once transferred on a substrate sheet may move to a guide roll
21
of the printing machine. Since a protecting printed layer is provided on one surface of a substrate sheet having no releasing property and a picture printed layer, an adhesive printed layer and the like are provided on the opposite surface in this case, the ink for forming a protecting printed layer once transferred on a substrate sheet may move to a surface of the picture printed layer, adhesive printed layer or the like when the surface protecting sheet is wound up at winding up part
17
after all the printed layers are formed.
Therefore, especial drying is required for the protecting printed layer after formation of the protecting printed layer in production process of the sheet material, in order to prevent occurrence of crack in the protecting printed layer situated on curved part of a molded article, and in order to prevent remaining of fluidity and stickiness on the protecting printed layer prior to irradiation with an active energy ray, when the transfer material or the surface protecting sheet is adhered to a molded article. For example, a printing system for use in a protecting printed layer as shown in
FIG. 10
have to be designed and constructed. A sheet to be printed is continuously fed out from winding off part
15
, then, first, ink is transferred onto a sheet to form a protecting printed layer at rotogravure printing part
23
for a protecting printed layer, subsequently, the protecting printed layer is dried with passing through drying part for a protecting printed layer
24
which has a length of 10 to 30 m and can raise temperature up to near 200° C. until it loses fluidity and stickiness, then, the sheet was once wound up at winding up part
17
. In this case, the printing speed can widely be controlled depending on drying property of the protecting printed layer because the printing system is independent of those for the other printed layers. The resulting wound sheet is then set again on winding off part
15
of the conventional multi-colour rotogravure printing machine as shown in
FIG. 9
, and an additional printed layer is formed.
However, the transfer material and the surface protecting sheet are produced by using the especial drying step for the protecting printed layer as described above, thus the sheet have to be once detached from the line after formation of the protecting printed layer
2
, and prior to formation of the other printed layer. The procedure therefore becomes troublesome. Further, the printing apparatus for forming the protecting printed layer have to be separately designed and constructed in the case of producing the transfer material or the surface protecting sheet. A cost for the apparatus is therefore
Crispino Richard
Lorengo J. A.
Nissha Printing Co. Ltd.
Wenderoth , Lind & Ponack, L.L.P.
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