Note: Descriptions are shown in the official language in which they were submitted.
CA 02450035 2003-12-18
Decorative Film For Use In Plastics Molding,
Process For Preparing The Same And Injection-Molded
Part. By Use Of The Same
This is a divisional application of Canadian Patent
Application No. 2,279,737 filed on August 5, 1999.
Background of the Invention
(1) Field of the Invention
The present invention relates to a novel decorative
film for use in plastics molding, a process for preparing
the decorative film and an injection-molded part obtained
by use of the decorative film. It should be understood .
that the expression "the invention" and the like
encompasses the subject matter of both the parent and the
divisional application.
(2) Description of Background Art:
As automobile parts, household appliance parts and
general industrial parts, plastics molded parts,
particularly polypropylene resin molded parts have widely
been used in the art. For the purpose of imparting
decoration, durability etc. to the polypropylene resin
molded part, a coating composition for use in plastics is
coated onto the surface of the molded part. However, a
coating film formed form the coating composition for use in
plastics generally shows poor adhesion properties to the
polypropylene resin. On the other hand, a primer is coated
for the purpose of improving adhesion properties.
As a method of coating the plastic coating composition
onto the above plastics molded part, an electrostatic spray
coating is employed so as to improve a coating efficiency
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CA 02450035 2003-12-18
with the result that an unsatisfactory coating efficiency
raises such problems that a product cost is high and that
non-uniform coating on a curved surface area provides poor
properties in adhesion properties and finished properties
of the plastic coating film.
For the purpose of solving the above problems, for
example, Japanese Patent Application Laid-Open Nos.
203048/83, 123469/88, 216717!88, 52416/96, and Japanese
Patent Publication No. 2550/96 etc. disclose a method of
coating a pigmented coating composition onto the surface of
a synthetic resin film to obtain a pigmented film, followed
by integrally molding by use of the pigmented film and a
molding resin so as to apply the pigmented film onto a
molded part and molded products obtained therefrom. Of the
above prior art, Japanese Patent Publication No. 2550/96
discloses, as pigmented coating composition, lacquer type
coating compositions containing, as base resins, acrylic
resin and fluorocarbon resin. However, coating of the
above coating compositions onto a polypropylene resin film
results poor adhesion properties to the polypropylene resin
film to be impractical.
As above described, adhesion of a coating film for use
in plastics or a pigmented coating film to polypropylene
resin is difficult. For the purpose of overcoming the
above difficulty, an attempt to coat~a known isocyanate-
curing type primer onto the polypropylene resin film has
been made. However, the use of the above film in the case
CA 02450035 2003-12-18
. r
where plastics is fabricated to a molded part having high
degree of deformation, for example, a bumper results such
problems as to develop coating film deffects such as cracks,
peeling, etc. of the primer coating film on a three
dimensional curved surface area showing high elongation of
the molded part. Further, the use of the above primer
raised such a problem that an electrostatic coating of a
topcoating composition onto the surface of the primer shows
a poor coating efficiency.
On the other hand, Japanese Patent Application Laid-
Open Nos. 123469/88 and 52416/96 disclose that the
pigmented film used therein is such that a metallic base
coat is coated on the surface of a coat film such as a
transparent film obtained by coating a solution obtained by
dissolving a polymer in an organic solvent onto the surface
of a substrate, followed by drying and evaporating the
organic solvent and stripping from the substrate, a
transparent film obtained by casting a solution of a
polymer onto a substrate followed by stripping from the
substrate or the like to form a metallic coating film.
However, the above pigmented film is a cast film and
has such disadvantages that fabrication to a film having a
uniform film thickness is difficult and that the
fabrication takes a long time. The use of an isocyanate-
curing type base coat coating composition and melamine-
curing type base coat coating composition in the above
metallic base coat, as known as a base coat for use in
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CA 02450035 2003-12-18
Y
automobiles, when fabrioated to a molded part having high
degree of deformation, for example, a bumper results such
problems as to develop coating film defects such as cracks,
peeling, etc. of the primer coating film on a.three
dimensional curved surface area showing high elongation of
the molded part.
Summary of the Invention:
It is an object of the present invention to provide a
decorative film for use in plastics molding, capable of
being uniformly and easily 3oined onto a plastic molded
product having a curved surface area and showing good
adhesion properties to both plastic. material and topcoating
film and good finished appearance.
It is another object of the present invention to
provide a decorative film for use in plastics molding,
capable of being uniformly and easily joined onto a plastic
molded product having a curved surface area, showing good
adhesion properties to both plastic material and topcoating
film, good finished appearance and electrostatic coating
workability, particularly~high electrostatic coating
efficiency of metallic coating composition and high
electrostatic coating efficiency of clear coating
composition.
It is another object of the present invention to
provide a decorative film for use in plastics molding,
capable of being uniformly and easily joined onto a plastic
molded product having a curved surface area, and showing
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good adhesion properties to plastic material and good
adhesion properties between a transparent film and a
pigmented layer.
It is another object of the present invention to
provide a plastic molded part showing good finished
appearance.
In a first aspect, the present invention provides a
decorative film for use in plastics molding and used. for
obtaining an integrally molded product with the decorative
film by a process which comprises setting the decorative
film on an inner side of an injection mold and subjecting a
molding polyolefin based resin to an injection molding, said
decorative film being a laminate film prepared by outwardly
and successively laminating a polyolefin film layer, a
primer layer, optionally a topcoating layer and a releasable
layer, said primer layer being a coating film formed from
an isocyanate-curing type resin composition containing (A)
a hydroxyl group-containing resin having a hydroxyl number
of 30 to 200 KOH mglg on an average and a weight average
molecular weight of 1000 to 80000, (B) a polyolefin based
resin and (C) a (blocked)polyisooyanate compound in such
mixing amounts that a number of the isocyanate group in the
component (C) is in the range of 0.1 to 0.9 per one
hydroxyl group in the component (A) and that the component
(B) is in the range of 1 to 90% by weight based on a total
weight of the components (A), (B) and (C), and having a
static glass transition temperature of 20 to 70 ~ , an
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elongation of 10~ or more and a tensile strength of 0.5
kgf/mmz or more; a process for preparing a decorative film
for use in plastics molding, which process comprises coating
an isocyanate-curing type coating composition containing (A)
a hydroxyl group-containing resin having a hydroxyl number
of 30 to 200 KOH mg/g on an average and a weight average
molecular weight of 1000 to 80000, (B) a polyolefin based
resin, (C) a (blocked)polyisocyanate compound and (E) an
organic solvent in such mixing amounts that a number of the
isocyanate group in the component (C) is in the range of
0.1 to 0.9 per one hydroxyl group in the component (A) and
that the component (B) is in the range of 1 to 90% by
weight based on a total weight of the components (A), (B)
and (C) onto one side of a polyolefin based film layer,
followed by drying at normal temperature or by heating to
form a primer layer having a static glass transition
temperature of 20 to ?0 ~ , an elongation of 10% or more and
a tensile strength of 0.5 kgf/mm2 or more; and an injection-
molded part obtained by setting the decorative film as
claimed in claib 1 on an inner side of an injection mold so
that the polyolefin film layer can join onto an outer
surface of a resin molded product, followed by carrying out
an injection molding by use of an injection molding
polyolefin based resin.
In a second aspect, the present invention provides a
decorative film for use in plastics molding and used for
obtaining an integrally molded product with the decorative
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film by a process which comprises setting the decorative
film on an inner side of an injection mold and subjecting a
polyolefin based resin for use in molding to an injection
molding, said decorative film being a laminate film
prepared by outwardly and successively laminating a
polyolefin film layer, a primer layer, optionally a
topcoating layer and a releasable layer, said primer layer
being a coating film formed from an isocyanate-curing type
resin composition containing (A) a hydroxyl group-
containing resin having a hydroxyl number of 30 to 200 KOH
mg/g on an average and a weight average molecular weight of
1000 to 80000, (B) a polyolefin based resin, (C) a (blocked)
polyisocyanate compound and (D) an electrically conductive
pigment in such mixing amounts that a number of the
isocyanate group in the component (C) is in the range of
0.1 to 0.9 per one hydroxyl group in the component (A), that
the component (B) is in the range of 1 to 90~ by weight
based on a total weight of the components (A), (B) and (C)
and that the component (D) is in the range of 5 to 300 parts
by weight per 100 parts by weight of a total weight of the
components (A), (B) and (C), and having a static glass
transition temperature of 20 to 70 ~ , an elongation of 10~
or more and a tensile strength of 0.5 kgf/mmz or more; a
process for preparing a decorative film for use in plastics
molding, which process comprises coating an isocyanate-
curing type coating composition containing (A) a hydroxyl
group-containing resin having a hydroxyl number of 30 to
CA 02450035 2003-12-18
200 KOH mg/g on an average and a weight average molecular
weight of 1000 to 80000, (B) a polyolefin based resin, (C) a
(blocked)polyisocyanate compound, (D) an electrically
conductive pigment and (E) an organic solvent in such
mixing amounts that a number of the isocyanate group in the
component (C) is in the range of 0.1 to 0.9 per one
hydroxyl group in the component (A), that the component (B)
is in the range of 1 to 90~ by weight based on a total
weight of the components (A), (B) and (C) and that the
component (D) is in the range of 5 to 300 parts by weight
per 100 parts by weight of a total weight of the components
(A), (B) and (C) onto one side of a polyolefin based film
layer, followed by drying at normal temperature or by
heating to form a primer layer having a static glass
transition temperature of 20 to 70 C , an elongation of 10%
or more and a tensile strength of 0.5 kgf/mmt or more; and ,
an infection-molded part obtained by setting the above
decorative film on an inner.side of an infection mold so
that the polyolefin film layer can loin onto an outer
surface of a resin molded product, followed by carrying out
infection molding by use of an infection molding polyolefin
based resin.
In a third aspect, the present invention provides a
decorative film for use in plastics molding and formed by
outwardly and successively laminating a plastic film layer,
optionally an adhesive layer, a pigmented layer and a
transparent film layer, said transparent film layer being a
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CA 02450035 2003-12-18
co-extruded laminate film prepared by laminating an outer
fluorocarbon polymer film layer and an inner acrylic
polymer film layer; and an injection-molded part obtained by
setting the above decorative film on an inner side of an
injection mold so that the plastic film layer can~join onto
an outer surface of a resin molded product, followed by
carrying out an injection molding by use of an injection
molding resin so that the injection molding resin can join
onto the plastic film layer of the decorative film.
Detailed Description of the Invention:
In the first and second aspect of the present
invention, the decorative film for use in plastics molding
is such that a plastic decorative film having a specified
primer layer is joined onto the surface of an injection-
molded part. The use of the decorative film makes it
possible to impart good durability, adhesion properties to a
topcoating and finished appearance.
More specifically, the present invention provides a
decorative film for, use in plastics molding and used for
obtaining an integrally molded product with the.decorative
film by a process which comprises setting the decorative
film on an inner side of an injection mold and subjecting a
molding polyolefin based resin to injection molding, the
decorative film being a laminate film prepared by outwardly
and successvelly laminating a polyolefin film layer, a
primer layer, a topcoating layer and a releasable layer,
the primer layer being a coating film formed from
isocyanate-curing type resin composition containing (A) a
hydroxyl group-containing resin having a hydroxyl number of
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CA 02450035 2003-12-18
30 to 200 KOH mg/g on an average and a weight average
molecular weight of 1000 to 80000, (B) a polyolefin based
resin and (C) a polyisocyanate or blocked polyisocyanate
compound in such mixing amounts that a number of the
isocyanate group in the component (C) is in the range of
0.1 to 0.9 per one hydroxyl group in the component (A) and
6
that the component (B) is in the range of 1 to 90% by
weight based on a total weight of the components (A), (B)
and (C), and having a static glass transition temperature
of 20 to 70'C, an elongation of 10% or more and a tensile
strength of 0.5 kgf/mm2 or more.
The present invention also provides~a decorative film
for use in plastics molding and formed by outwardly and
successively laminating a plastic film layer, optionally an
adhesive layer, a pigmented layer and a transparent film
layer, the transparent film layer being a co-extruded
laminate film prepared by laminating an outer fluorocarbon
polymer film layer and an inner acrylic polymer film layer.
The above decorative film is a laminate film prepared
by laminating a primer layer having, as a sole coating
film, a static glass transition temperature of 20 to ?0t:,
preferably 20 to 60 ~ , an elongation of 10K or more,
preferably 20 to 500%, and a tensile strength of 0.5 kgf/mmx
or more, preferably 0.5 to 3 kgf/mmZ onto the surface of a
polyolefin based film layer.
The above polyolefin based film layer may include a
film mainly containing known thermoformable polyolefin
based resin. Examples of the polyolefin based resin may
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include polyolefin resins, modified polyolefin resins,
etc., for example, polyethylene resin, polybutylene resin,
polypropylene resin, ethylene-propylene copolymer and the
like. A film thickness of the polyolefin based film layer
is in the range of about 20 to 100~u m, preferably about 100
to 300 ~u m. A film thickness less than about 20 ,u m may
shrink the primer while being dried, resulting deforming the
decorative film and making fabrication difficult. On the
other hand, a film thickness more than about 1000~u m may
undesirably make fabrication difficult.
The polyolefin based film layer may optionally contain
additives, for example, colorants such as pigments, dyes and
the like, electrically conductive pigments, fillers,
ultraviolet light absorbers, ultraviolet light stabilizers,
heat stabilizers and the like.
A static glass transition temperature lower than 20'G
of the primer layer formed on the surface of the polyolefin
based resin film layer results in that adhesion between
primer layers or adhesion thereof with other substrate on
rolling the resulting film makes handling difficult, that
adhesion between primer layers or adhesion thereof with
other substrate on stacking molded parts makes handling
difficult, and that adhesion of refuses, spittings, etc.
onto the primer layer may take place. On the other hand,
the above temperature higher than 'TO ~ may develop cracks on
the primer layer, or may separate the primer layer from the
polyolefin based film layer on folding the decorative film.
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w
A primer layer having an elongation less than 10% may
develop cracks on the primer layer, or may separate the
primer layer from the polyolefin based film layer on folding
the decorative film. A primer layer having a tensile
strength less than 0.5 kgf/mm2 may results in that a primer
lay may be squeezed on an area where a high pressure is
applied on injection molding so that a film thickness of
the primer layer may become thinner in the above area,
resulting in making it impossible to form a uniform primer
layer.
The glass transition temperature, elongation and
tensile strength of the primer layer may be controlled by
varying kinds and mixing amounts of the components (A), (B)
and (C) in the first aspect of the present invention, or the
components (A)-, (B), (C) and (D) in the second aspect of
the present invention.
In the first aspect of the present invention, the
decorative film is prepared by a process which comprises
coating composition containing (A) a hydroxyl group-
containing resin having a hydroxyl number of 30 to 200 KOH
mg/g on an average and a weight average molecular weight of
1000 to 80000, (B) a polyolefin based resin, (C) a (blocked)
polyisocyanate compound and (E) an organic solvent in such
mixing amounts that a number of the isocyanate group in the
component (C) is in the range of 0.1 to 0.9 per one hydroxyl
group in the component (A) and that the component (B) is in
the range of 1 to 90~ by weight based on a total weight of
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1
the components (A), (B) and (C) onto one side of a
polyolefin based film layer, followed by drying at normal
temperature or by heating.
In the second aspect of the present invention, the
decorative film is prepared by a process which comprises
coating an isocyanate-curing type coating composition
containing (A) a hydroxyl group-containing resin having a
hydroxyl number of 30 to 200 KOH mg/g on an average and a
weight average molecular weight of 1000 to 8000, (B) a
polyolefin based resin, (C) a (blocked)polyisocyanate
compound, (D) an electrically conductive pigment and (E) an
organic solvent in such mixing amounts that a number of the
isocyanate group in the component (C) is in the range of 0.1
to 0.9 per one hydroxyl group in the component (A) and that
the component (B) is in the range of 1 to 90~ by weight
based on a total weight of the components (A), (B) and (C)
onto one side of a polyolefin based film layer, followed by
drying at normal temperature or by heating. The
electrically conductive pigment (D) may be mixed in such an
amount that the primer layer has a surface resistivity to
make an. electrostatic coating of a topcoating possible, but
preferably may be mixed in an amount of 5 to 300 parts by
weight, particularly 10 to 200 parts by weight per 100
parts by weight of a total weight of the components (A), (B)
and (C). The primer layer preferably has a surface
resistivity normally in the range of 1.0 x 109 n or less,
particularly 1.0 x 10a n to 1.0 x 102 0 . When more
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CA 02450035 2003-12-18
than 1.0 X 10' ~ , an electrostatic coating efficiency may
undesirably be reduced.
The isocyanate-curing type resin compositions of the
first and second aspects of the present invention are
explained hereinbelow.
Hydroxyl group-containing resin (A):
The hydroxyl group-containing resin (A) may include a
resin having a hydroxyl number of 30 to 200 KOH mg/g on an
average, preferably 35 to 150 KOH mg/g on an average, and a
weight average molecular weight of 1000 to 8000, preferably
2000 to 60000. A hydroxyl number less than 30 KOH mg/g on
an average may undesirably reduce the elongation and
tensile strength of the primer layer as well as adhesion
properties to the topcoating film. A hydroxyl number more
than 200 KOH mg/g on an average may undesirably reduce water
resistance of the primer layer. A weight average molecular
weight less than 1000 may undesirably reduce the elongation
and tensile strength of the primer layer. On the other
hand,.when more than 8000, an increased viscosity of the
primer may undesirably make handling difficult.
The hydroxyl group-containing resin may preferably
include hydroxyl group-containing polyester resin, hydroxyl
group-containing alkyd resin, hydroxyl group-containing
vinyl resin, hydroxyl group-containing epoxy resin and the
like.
The hydroxyl group-containing polyester resin may
include, for example, ones prepared by esterification
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reaction or ester exchange reaction of polybasic acids, for
example, compounds having 2 to 4 of carboxyl group or
methylcarboxylate group in one molecule, Por example,
(anhydrous)phthalic acid, isophthalic acid, terephthalic
acid, (anhydrous)maleic acid, (anhydrous)pyromellitic acid,
(anhydrous)trimellitic acid, (anhydrous)succinic acid,
sebacic acid, azelaic acid, dodecanedicarboxylic acid,
dimethyl isophthalate, dimethylterephthalate and the like
with polyhydric alcohols, for example, alcohols having 2 to
6 of hydroxyl group in one molecule, for example, ethylene
glycol, propylene glycol, neopentyl glycol, 1,6-hexanediol,
diethylene glycol, triethylene glycol, trimethylol propane,
pentaerythritol, glycerin, tricyclodecane dimethanol and
the like under the condition that hydroxyl group is within
the above range.
The.hydroxyl group-containing alkyd resin may include
ones prepared by subjecting monobasic acids, for example,
fatty acids such as castor oil fatty acid, soybean oil
fatty acid, tall oil fatty acid, linseed oil fatty acid and
the like, benzoic acid, etc. in addition to the above
polybasic acid and polyhydric alcohol components to
esterification reaction or ester exchange reaction under the
condition that hydroxyl group is within the above range.
The hydroxyl group-containing vinyl resin may include,
for example, ones prepared by subjecting the following
hydroxyl group-containing unsaturated monomer and other
unsaturated monomer to radical copolymerization.
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Examples of the hydroxyl group-containing unsaturated
monomer may include C2-a hydroxyalkyl esters of acrylic
acid or methacrylic acid, for example, 2-hydroxyethyl (meth)
acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl
(meth)acrylate, hydroxybutyl (meth)acrylate and the like;
monoesters of polyether polyols such as polyethlene glycol,
polypropylene glycol, polybutyl:ene glycol and the like with
unsaturated carboxylic acid such as (meth)acrylic acid and
the like; monoethers of polyether polyol such as
polyethylene glycol; polypropylene glycol, polybutylene
glycol and the like with hydroxyl group-containing
unsaturated monomer such as 2-hydroxyethyl (meth)acrylate
and the like; adducts of a , R -unsaturated carboxylic acid
with monoepoxy compound such as Cardura E10 (marketed by
Shell Kagaku K.K.), a -olefin epoxide and the like;
adducts of glycidyl (meth)acrylate with monobasic acid such
as acetic acid, propionic acid, p-t-butyl benzoic acid,
fatty acids and the like; monoesterified compound or
diesterified compound of acid anhydrous group-containing
unsaturated compound with glycols such as ethylene glycol,
1,6-hexanediol, neopentyl glycol and the like; hydroxyalkyl
vinyl ether such as hydroxyethyl vinyl ether and the like;
chlorine-containing, hydroxyl group-containing monomer such
as 3-chloro-2-hydroxypropyl (meth)acrylate and the like;
allyl alcohol and the like. Examples of other unsaturated
monomers may include C,-z~ alkylesters or cycloalkylesters
of acrylic acid or methacrylic acid, for example, methyl
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(meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate,
butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl
(meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate,
lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl
(meth)acrylate and the like; acid unsaturated monomer such
as (anhydrous)maleic acid, (meth)acrylic acid and the like;
epoxy group-containing unsaturated monomer such as glycidyl
(meth)acrylate, and the like; silane unsaturated compound
such asr -(meth)acryloyloxypropyltrimethoxysilane and the
like; C2-,e alkoxyalkylester of acrylic acid or methacrylic
acid, for example, methoxybutyl (meth)acrylate,
methoxybutyl (meth)acrylate, methoxyethyl (meth)acrylate,
ethoxybutyl (meth)acrylate and the like; aromatic
unsaturated compound such as styrene, vinyltoluene and the
like; chain alkyl vinyl ethers such as ethyl vinyl ether, n-
propyl vinyl ether, isopropyl vinyl ether, butyl vinyl
ether, tert-butyl vinyl ether, pentyl vinyl ether, hexyl
vinyl ether, octyl vinyl ether and the like; cycloalkyl
vinyl ethers such as cyclopentyl vinyl ether, cyclohexyl
vinyl ether and the like; aryl vinyl ethers such as phenyl
vinyl ether, trivinyl phenyl ether and the like; aralkyl
vinyl ethers such as benzyl vinyl ether, phenethyl vinyl
ether and the like; allyl ethers such as allyl glycidyl
ether, allyl ethyl ether and the like; vinyl esters such as
vinyl acetate, vinyl propionate, vinyl lactate, vinyl
butyrate, vinyl isobutyrate, vinyl caproate, vinyl
isocaproate, vinyl pivalate, vinyl caprate, Veova monomer
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(marketed by Shell Kagaku K.K.) and the like; propenyl
esters such as isopropenyl acetate, isopropenyl propionate
and the like; olefin based unsaturated monomer such as
ethylene, propylene, butylene, vinyl chloride and the like;
diene based unsaturated monomer such as butadiene, isoprene,
chloroprene and the like; and the like.
Examples of the hydroxyl group-containing epoxy resin
may include Epikote 1004 (trade name, marketed by Oil Shell
Epoxy Co., Ltd., bisphenol-epichlorohydrin), esterified
compounds of the above epoxy resins with a fatty acid such
as the above monobasic acid, and the like.
The above hydroxyl group-containing resins may be used
alone or in combination. In the case where two or more
resins are used, an average hydroxyl number and an average
weight average molecular weight of two or more combined
resins may be controlled so as to be within the
abovementioned ranges.
The polyolefin based resin may include chlorinated
polyolefin resin, modified polyolefin resin and the like.
The above chlorinated polyolefin resin may preferably
include a chlorinated polypropylene resin having a degree-
of chlorination 10 to 50% by weight, preferably 15 to 30%
by weight, and a weight average molecular weight of about
3000 to 150000, preferably about 10000 to 100000. A degree
of chlorination less than 10~G by weight reduces solubility
in an organic solvent. On the other hand, a degree of
chlorination more than 50~d by weight undesirably reduces
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adhesion properties to the polyolefin film layer. The
chlorinated polyolefin based resin may preferably contain
an acid monomer in copolymerization. The acid monomer
component may be contained in the range of about 10~ by
weight or less, preferably about 1 to 5% by weight on the
basis of the polymer. A weight average molecular weight
less than about 3000 undesirably reduces fabrication
properties. On the other hand, a weight average molecular
weight more than about 150000 undesirably increase a
viscosity of the solution, resulting in reducing coating
workability. Examples of the chlorinated polyolefin resin
may include Superchlon 8921, Superchlon SK-30, Superchlon S-
801 (all trade names, marketed by Nippon Paper industries
Co., Ltd.) and the like.
The modified polyolefin resin may include resins
prepared by modifying, for example, graft copolymerizing
(chlorinated)golyolefin resin with, for example, hydroxyl
group-containing unsaturated monomer, acid monomer, epoxy
group-contafning unsaturated monomer and other unsaturated
monomer such as alkyl ester of (meth)acrylic acid as
described in the aforementioned hydroxyl group-containing
vinyl based resin. The modified polyolefin resin may
further include ones prepared by modifying the resin
modified with the monomer as above by use of a functional
group introduced into the resin, for example, ones prepared
by reacting an epoxy group-containing resin with (meth)
acrylic acid to introduce unsaturated group into the resin,
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CA 02450035 2003-12-18
followed by subjecting to a radical polymerization reaction
with an unsaturated monomer such as alkyl ester of (meth)
acrylic acid, and ones prepared by reacting a hydroxyl
group-containing resin with a polyisocyanate compound and a
hydroxyl group-containing unsaturated monomer to introduce
unsaturated group into the resin, followed by subjecting to
a radical polymerization reaction with an unsaturated
monomer such as alkyl ester of (meth)acrylic acid. Examples
of the modified polyolefin resin may include Superchlon
1426, Superchlon 1436, Superchlon 334 (all trade names;
marketed by Nippon Paper Industries Co., Ltd.), Acrydic LU-
835 (trade name, marketed by Dainippon Ink & Chemicals,
Inc.), and the like.
A mixing amount of the polyolefin based resin(B) is in
the range of 1 to 90~ by weight, preferably 2 to 80% by
weight based on a total iaeight of the components (A), (B)
end (C). A mixing amount less than 1~6 by weight reduces
adhesion properties to a polyolefin based sheet. On the
other hand, a mixing amount more than 90~ by weight may
reduce adhesion properties to a topcoating.
The use of the (blocked)polyisocyanate compound (C)
makes possible crosslinking of. the hydroxyl group-
containing resin (A) and impart suitable adhesion
properties, elongation and tensile strength to the primer
layer, resulting in making it possible to form a coating
film suitable for molding and fabrication.
The (blocked)polyisocyanate compound (C) may include
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polyisocyanate compounds and blocked polyisocyanate
compounds prepared by partly or completely blocking the
isocyanate group of the above compound with a blocking
agent. Examples of the polyisocyanate compounds and
polyisocyanate compounds to be blocked may include organic
diisocyanates, for example, aliphatic diisocyanates such as
hexamethylene diisocyanate and_trimethylhexamethylene
diisocyanate; cycloaliphatic diisocyanates such as
hydrogenated xylylene diisocyanate, isophorone diisocyanate;
and aromatic diisocyanates such as tolylene diisocyanate
and 4'-diphenylmethane diisocyanate; reaction products of
respective organic diisocyanates with polyhydric alcohol;
adducts thereof with low molecular weight polyester resin or
water; cyclic polymers between respective organic
diisocyanates; isocyanate ~ biurets, and the like: Typical
examples of commercially available ones may include Burnock
D-?50, -800, DN-950, -950 and 15-455 (a11 trade names,
marketed by Dainippon Ink & Chemicals, Inc.,), Desmodur L, -
N, -HL, -IL and -N3390 (all trade names, marketed by Bayer
Ltd., Germany), Takenate D-102, -202, -110N and -123N (all
trade names, marketed by Takeda Chemical Industries, Ltd.),
Coronate L, -HL, -EH and 203 (all trade names, marketed by
Nippon Polyurethane Industry), Duranate 24A-90XC, Duranate
E5004-90T, Duranate MFK-60 (all trade names, marketed by
Asahi Chemical Industry Co., Ltd.), and the like. Of
these, aliphatic diisocyanate, cyclic aliphatic
diisocyanate, reaction products thereof with polyhydric
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CA 02450035 2003-12-18
alcohol, cyclic polymer thereof, isocyanate~ biurets
thereof, and the like are preferred.
Examples of the blocking agent may include phenol based
blocking agent such as phenol, cresol, xylenol,
nitrophenol, chlorophenol, methyl hydroxybenzoate and the
like; lactam based blocking agent such ase -caprolactam, 8 -
valerolactam, r -butylolactam, R -propiolactam and the like;
alcohol based blocking agent such as methanol, ethanol, n-
propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl
alcohol, t-butyl alcohol, benzyl alcohol, methoxymethanol
and the like; oxime blocking agent such as formamidoxime,
acetoaldoxime, acetoxime, methyl ethyl ketoxime,
diacetylmonooxime, benzophenonoxime, cyclohexaneoxime and
the like; active methylene based blocking agent; dimethyl
malonate, diethyl malonate, ethyl acetoacetate,. methyl
acetoacetate, acetylacetone and the like.
A mixing amount of the (blocked)polyisocyanate compound
(C) is such that a number of the isoeyanate group in the
component (C) is in the range of 0.1 to 0.9, preferably 0.2
to 0.7 per one hydroxy~group in the component (A). When a
number of the isocyanate group is less than 0.1, formation
of a crosslinked coating fila~ is made impossible, resulting
in undesirably reducing the elongation and tensile strength
of the coating film. On the other hand, when more than 0.9,
reduction of the hydroxyl group remaining in the
crosslinked coating film results poor adhesion properties to
the topcoating film.
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CA 02450035 2003-12-18
The electrically conductive pigment (D) used in the
second aspect of the present invention may include known
electrically conductive pigments, but particularly may
include white or lightly gray electrically conductive
pigments which scarcely cause such adverse effects on the
appearance of topcoating film that brightness of the
topcoating film varies depending on absorption or reflection
of the light transmitting through the topcoating film on
the surface of the primer layer.
Examples of the white electrically conductive pigment
may preferably include an antimony-doped tin dioxide
pigment thereinafter referred to as "tin dioxide/antimony
(dope)"7 , zinc oxide pigment and the like. The above tin
dioxide pigment may include ones prepared by doping a tin
dioxide component as a semiconductive substance with an
antimony component to form a donor level of an electron,
resulting in increasing electrical conductivity, for
example, tin dioxide/antimony (dope) alone and a coating
part prepared by coating the tin dioxide/antimony (dope)
onto other substrate. Examples of other substrate, onto
which the tin dioxidelantimony (dope) and the zinc oxide
pigment are coated, may include titanium oxide, potassium
titanate, aluminum borate, barium sulfate, mica, silica and
the like.
Examples of the shapes of an electrically conductive
powder to be used may include shapes of fiber, needle,
tetrapot, flake, sphere and the like.
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CA 02450035 2003-12-18
Examples of the tin dioxide/antimony (dope) may include
Dentall WK-1005, Dentall WK-100W, Dentall WK-20, Dentall WK-
300R (trade names, all marketed by Otsuka Chemical Co.,
Ltd., potassium titanate, fiber substrate), Dentall WK-500
(trade name, marketed by Otsuka Chemical Co., Ltd.,
monoclinic titanium oxide, fiber substrate), MEC-300, MEC-
500, MEC-X00, SEC-250 (trade names, all marketed by Tayka
Corporation, electrically conductive mica, mean particle
size: 4 to 10 ~u m), T-1, W-1, W-10 (trade names, all
marketed by Mitsubishi Materials Corporation, titanium
oxide substrate, sphere, mean particle size: 0.2 ~ m), FT-
1000, FT-2000, FT-2000W (trade names, all marketed by
Ishihara Sangyo Kaisha, Ltd., needle, titanium white
substrate, average longitudinal axis: 1.6 to 6 ~ m, average
lateral axis: 0.05 to 0.2 ~ m), and the like.
Examples of the zinc oxide powder may include a
spherical zinc oxide powder having a diameter of about 0.1
,u m to 2 ~ m, for example, FW-102 (trade name, marketed by
Sumitomo Aluminum Co., Ltd.), 23-K (trade name, marketed by
Hakusui Chemical Industries), a tetrapot type zinc oxide
powder having a length of about 0.5 ~ m to 100 ~e m,
preferably about 1 ~u m to 60 ~u m, for example, Panatetra
(trade name, marketed by Matsushita Amtec Co., Ltd.) and the
like.
Of the electrically conductive pigments, a fiber-shaped
electrically conductive pigment having an average fiber
length of about 1 ~u m to 50 ~u m, particularly about 2 ,~ m to
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CA 02450035 2003-12-18
40 ~ m, and an average fiber diameter of about 0.01 ~u m to 5
~ m, particularly about 0.05 ,u m to 2 ~ m is preferable.
The organic solvent (E) used in the first and second
aspects of the present invention is a solvent used for
dissolving or dispersing the components (A), (B) and (C) in
the first aspect or the components (A), (B), (C) and (D) in
the second aspect and controlling viscosity so as to make
possible coating, printing, etc. Examples of the organic
solvent (E) may include hydrocarbon series such as hexane,
heptane, toluene, xylene and the like; alcohol series such
as propanol, butanol and the like; cellosolve,
methylcellosolve, butylcellasolve, methylcarbitol, ether
series such as diethylene glycol monoethyl ether,
diethylene glycol monobutyl ether, triethylene glycol
monomethyl ether and the like; ketone series such as
acetone, methyl ethyl ketone, 2-pentanone, methyl isobutyl
ketone, isophorone and the like; acetate series such as
methyl acetate; ethyl acetate, propyl acetate, butyl
acetate, 2-ethylhexyl acetate, cellosolve acetate, carbitol
acetate and the like, and the like.
A mixing amount of the organic solvent (E) may vary
depending on the components (A), (B), (C) and (D) as well
as other additives, but is normally such that a solid
content is in the range of about 10 to 90% by weight,
preferably about 30 to 70% by weight.
The isocyanate-curing type resin composition may
contain a cellulose based resin such as nitrocellulose,
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CA 02450035 2003-12-18
acetyl cellulose, cellulose acetate butylate, cellulose
propionate and the like. Of these, cellulose acetate
butylate is preferable. Examples of the trade names thereof
may include CAB551-0.2, CAB551-0.01, CAB531-1, CAB-381-0.5,
CAB381-0.1, CAB381-2 (trade names, all marketed by Eastman
Chemical Company), and the like. A mixing amount of the
cellulose based resin is in the range of about 100 parts by
weight or less, preferably about 70 parts by weight or
less, more preferably about 10 to 60 parts by weight per 100
parts by ~teight of the components (A), (B) and (C). The
cellulose based resin does not impart tackiness to the
isocyanate-cured coating film and has advantages free of
troubles such as fusing and bonding on contacting between
primer coating film surfaces of a molded product,
development of flaws on contacting with others, and adhesion
of refuse, spittings, etc. onto the surface of the coating
film.
The isocyanate-curing type resin composition may
optionally contain additives, for example, coloring agent
such as pigments, dyes, etc., electrically conductive
pigments, fillers, ultraviolet light absorber, ultraviolet
light stabilizer, heat stabilizer, catalysts and the like.
The decorative film in the first and second aspects of
the present invention may be prepared by coating the above
isocyanate-curing type resin composition onto the surface
of the polyolefin based film layer, followed by drying at
normal temperature or by heating. A coating method may
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CA 02450035 2003-12-18
include, for example, spray coating, roll coating, knife
coating, curtain flow coating, silk screen coating, gravure
printing and the like.
The primer layer has a dry film thickness in the range
of about 5 to 100 ,u m, preferably about 30 to 60 ,u m. A
film thickness less than about 5 ~ m makes thiner a film
thickness of the primer layer in an area where a degree of
deformation on molding is high, resulting in reducing
durability, adhesion properties, etc. On the other hand, a
film thickness more than about 100 N m undesirably results
a high production cost, long drying time, increased
development of coating film deffects such as bubbling,
blisters and the like, development of shrinkage on the
surface of the coating film due to difference in a degree of
curing between the surface and interior of the coating
film, and the like.
Prior to coating the primer, the surface of the
polyolefin based film layer may be treated by a corona
discharge treatment or the like.
Heating conditions of the isocyanate-curing type resin
composition may vary depending on kinds of organic solvents
to be used and formulations, but, for example, are such as
in the range of about 30 to 100>r and in the range of about
1 to 90 minutes:
The decorative film in the first and second aspects of
the present invention is a laminate film prepared by
outwardly and successively laminating a polyolefin based
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CA 02450035 2003-12-18
film layer, primer layer, optionally topcoating layer, and
optionally a releasable film layer. The topcoating layer
may be explained hereinbelow. In the case where the
topcoating layer is not formed, after molding, a topcoating
composition may be coated to form a topcoating layer.
Onto another surface of the polyolefin based film
layer, that is, an opposite surface to the primer layer, a
thermoplastic resin layer may be applied. The thermoplastic
resin may preferably include a resin having a heat
softening point lower than that of the polyolefin based
resin. The use of the thermoplastic resin layer makes it
possible to recover a molded part and a decorative film
separately, for example, by heating a molded part after use
at the softening temperature or higher of the thermoplastic
resin, but at a temperature lower than the softening
temperature of the polyolefin based resin, followed by
separating between the thermoplastic resin layer and a
molding polyolefin resin layer.
The releasable film makes possible to prevent
separation due to adhesion between an inner surface of a
mold and the surface of the primer layer. The releasable
film may include any known releasable films. Examples of
the releasable film may include papers and films
respectively treated with a releasing agent such as
silicone, wax, fluorocarbon resin and the like, and ones
prepared by laminating a releasable film such as a film
showing releasable properties by itself. The releasable
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CA 02450035 2003-12-18
r
film has a film thickness normally in the range of about l0
to 1000 ~u m, preferably about 20 to 500 ,u m.
The decorative film for use in plastics molding in the
third aspect of the present invention may be~prepared by
joining a decorative film having a specified transparent
film layer onto the surface of an injection-molded part.
The use of the above decorative film makes it possible to
impart good durability and finished appearance to the molded
part.
In the third aspect of the present invention, the
plastic film layer in the decorative film may be used for
the purpose of joining the decorative film onto the surface
of the plastic molded product. That is, the decorative
film and a molding plastic material are subjected to a co-
extrusion molding so that a pigmented layer and the
transparent film layer are melted and joined through the
plastic film layer with the plastic molded product.
Specific examples of the resins used in the above
plastic film layer may include thermoplastic resins such as
polyethylene, polypropylene, polyisobutylene,
polybutadiene, polystyrene, polychloroprene, polyvinyl
chloride, polyvinyl acetate, nylon, acrylic resin,
polycarbonate, cellulose, polyethylene terephthalate,
polyacetal, AS resin, ABS resin and the like.
The resin used in the plastic film layer may preferably
include the same type thermoplastic resins as those used in
the molded part from the standpoints of joining properties
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CA 02450035 2003-12-18
and workability.
The plastic film layer may optionally contain known
additives such as coloring agents, fillers, plasticizers,
heat stabilizers and the like.
The plastic film layer desirably has a film thickness
normally in the range of about 20 to 1000 ,u m, preferably
about 100 to 300 ~ m. A film thickness less than about 20
,u m may undesirably reduce the finished appearance of the
plastic molded part. On the other hand, a film thickness
more than about 1000 ~u m may undesirably results in showing
poor workability due to difficulties in handling and in
reducing finished appearance of the plastic molded part.
A substrate treatment such as the corona discharge
treatment and the like may optionally be carried out between
the plastic film layer, the optional adhesive layer and the
pigmerited layer.
The optionally used adhesive layer is a layer formed
from known pressure-sensitive and heat-sensitive adhesives,
for example, natural rubber, polyisobutylene, acrylic resin,
ethylene/vinyl acetate copolymer, polyurethane, polyester,
silicone rubber, fluorocarbon rubber, polyvinyl butylal and
the like. The adhesive layer ~ay also contain, for example,
adhesion-imparting agent, adhesion controlling agent,
antiaging agent, stabilizer, coloring agent and the like.
The adhesive layer has a coating film thickness normally in
the range of about 5 to 60 ~u m, preferably about 7 to 40
m.
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CA 02450035 2003-12-18
In the third aspect of the present invention, the
pigmented layer in the decorative film may also include,
for example, a coating film formed by use of a pigmented
coating composition prepared by mixing a color pigment with
a non-curing type, thermoplastic, organic solvent-
evaporating type resin.
The organic solvent-evaporating type coating
composition is a composition capable of forming a dry
coating film only by evaporating the organic solvent, and
may include, for example, coating compositions prepared by
dissolving or dispersing a resin such as polyester resin,
alkyd resin, epoxy resin, vinyl acetate resin, vinyl
chloride resin, vinyl acetate/vinyl chloride copolymer
resin, fluorocarbon resin, urethane resin, silicone resin,
rubber based resin, acrylic resin, cellulose based resin and
the like into the organic solvent. The above may also
include graft resins formed from at least two resins
exemplified as above, mixed resins of at least two resins
exemplified as above, and the like. The above exemplified
resins may also contain a functional group such as an
oxidative polymerization unsaturated group, hydrolyzable
silyl group and the like, resulting in being partly cured
by use of the functional group. The above exemplified
resins having a functional group such as hydroxyl group and
the like may be mixed with, for example, a polyisocyanate
compound curing agent to partly be cured. The above
exemplified resins having epoxy group may be mixed, for
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CA 02450035 2003-12-18
r ,
example, with a polycarboxylic acid compound curing agent
to partly be cured. The partial curing may be carried out
to such an extent that the functional group of the resin is
reacted in an amount of about 50 moles or less, preferably
40 mole% or less.
Examples of the color pigment may include inorganic
pigments such as carbon black, titanium oxide and the like;
organic pigments, for example, quinacridone series such as
quinacridone red and the like; azo series such as pigment
red and the like; phthalocyanine series such as
phthalocyanine blue, phthalocyanine green and the like; and
the like; flake-shaped. powders representing metallic feeling
or pearl feeling color as in the case of aluminum powder,
copper powder, mica-like iron oxide powder, bronze powder,
stainless steel powder and the like, and the like. These
pigments may be used alone or in combination. Of these
pigments, the flake-shaped powder capable of representing a
metallic feeling or pearl feeling color is preferably used.
A mixing amount of the coloring agent may vary
depending on performances, kinds, eto: as required, but
desirably is in the range of about 0.5 to 300 parts by
weight, preferably about 3 to 150 parts by weight per 100
parts by weight of the resin solid content. In addition to
the above, the pigmented resin composition may optionally
contain plasticizers, fillers, flowability controlling
agents, ultraviolet light absorbers and the like.
The pigmented layer may be formed by means of a gravure
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CA 02450035 2003-12-18
coater, silk screen, offset printing, knife coater, roll
coater, air spray, brush and the like. The pigmented layer
desirably has a film thickness in the range of about 10 to
100 a m, particularly about 20 to 50 ,u m.
The pigmented layer may be dried by leaving to stand at
room temperature or b~y heating depending on kinds of the
organic solvents and resin compositions to be used.
The pigmented layer, as a sole coating film prior to
molding, has a static glass transition temperature of 20 to
90 ~ , preferably 20 to 80 ~ , an elongation of 5,K or more,
preferably 5 to 500%, and a tensile strength of 0.5 kgf/mm2
or more, preferably 2 to 5 kgf/mm2.
A pigmented layer having a static glass transition
temperature lower than 20 ~ may result a film showing poor
durability. On the other hand, when higher than 90 ~ ,
cracks may undesirably develop in the pigmented layer on
folding the decorative film. A pigmented layer having an
elongation less than 5K may result that cracks may
undesirably develop in the pigmented layer on folding the
decorative film: A pigmented layer having a tensile
strength less than 0.5 kgf/mm2 results such disadvantages
that the primer layer may be squeezed in an area where a
high pressure is applied on injection molding and has a
thiner film thickness in that area, resulting in making it
impossible to obtain a uniform pigmented layer, and so
forth.
The above organic solvent may include ones capable of
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CA 02450035 2003-12-18
dissolving or dispersing the resin without particular
limitations. Example of the organic solvent may include
the same ones as in the organic solvent (E).
A mixing amount of the above organic solvent is such
that a solid content is in the range of about 10 to 90% by
weight, preferably about 30 to 70~ by weight.
In the third aspect of the present invention, the
transparent film layer used in the decorative film is a co-
extrusion laminate film prepared by laminating an outer
fluorocarbon polymer film layer and an inner acrylic polymer
film layer.
Examples of the polymers used in the fluorocarbon
polymer film layer may include vinyl fluoride polymer,
vinylidene fluoride polymer, ethylene trifluoride polymer,
alkylene copolymers thereof, and the like.
The fluorocarbon polymer film may also contain a
copolymer of a fluorocarbon monomer with an acrylic monomer.
The fluorocarbon-acrylic copolymer may preferably contain
the fluorocarbon monomer in an amount of more than 50~ by
weight.
The acrylic polymer film layer may preferably include
an acrylic polymer having a glass transition temperature in
the range of 60 to 1501r , preferably 90 to 140 ~ . The above
polymer may be a homopolymer or copolymer. A glass
transition temperature lower than 60 ~ may undesirably
develop the deformation of the decorative film when a
temperature of a molded part mounted on an automobile is.
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CA 02450035 2003-12-18
raised. On the other hand, a glass transition temperature
higher than 150 ~ undesirably makes molding and fabrication
difficult.
The glass transition temperature ~(Tg) is a numerical
value calculated according to the following equation. The
above numerical values were converted from " K" to ' ~ "
to be represented.
1/Tg = W~/Tg~+Wz/Tgx+W~/Tg~ ___
where T, represents a glass transition temperature (' K) of
the above polymer. 'Tg~, Tgx, Tga, ---" represent
respective glass transition temperatures ( ' K) of
respective homopolymers of respective monomers used in the
preparation of a copolymer. "W~, Wx, Wa, ---" represent
respectively "~ by weight" of respective monomers used in
the preparation of a copolymer. Glass transition
temperatures (' K) of homopolymers are values cited from
Polymer Hand Book (Second Edition, Edited by J. Brandrup~
E.H. Immergut).
100 = W~ + Wx + Wa ~ + ___
The above polymer preferably has a number average
molecular weight in the range of 20000 or more, preferably
~t0000.to 1000000. A number average molecular weight less
than 20000 undesirably reduces durability of the film.
The acrylic polymer film may also contain a copolymer
of an acrylic monomer with a fluorocarbon monomer. The
acrylic-fluorocarbon copolymer may preferably contain the
acrylic monomer in an amount of more than 50% by weight.
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CA 02450035 2003-12-18
Examples of the acrylic monomer may include ones having
a Tg of 60 ~ or higher, for example, methyl methacrylate,
ethyl methacrylate, ter-butyl methacrylate and the like.
These monomers may be used alone or in combination.
The above monomers may be used in combination with
monomers having a Tg less than 60 ~ as exemplified
hereinafter. Specific examples thereof may include alkyl
esters and cycloalkyl esters such as methyl acrylate, ethyl
acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl
acrylate, isobutyl acrylate, hexyl acrylate, 2-ethylhexyl
acrylate, n-octyl acrylate, decyl acrylate, lauryl
acrylate, stearyl acrylate, cyclohexyl acrylate, n-propyl
methacrylate, isopropyl methacrylate, n-butyl methacrylate,
isobutyl methacrylate, hexyl methacrylate, 2-ethylhexyl
methacrylate, octyl methacrylate, decyl methacrylate, lauryl
methacrylate, stearyl methacrylate, cyclohexyl methacrylate
and the like; hydroxyl group-containing monomers such as 2-
hydroxyethyl (meth)acrylate, 3-hydroxypropyl acrylate and
the like. Monomers having a Tg of 60 ~ or higher, for
example, (meth)acrylic acid, 2-hydroxypropyl methaerylate,
styrene, (meth)acrylamide, glycidyl (meth)acrylate and the
like, may be used in combination with the above polymer.
In the third aspect of the present invention, the
transparent film layer may preferably include a co-
extrusion laminate film prepared. by laminating an outer
layer of vinylidene polyfluoride film layer and an inner
layer of polymethylmethacrylate film layer from the
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CA 02450035 2003-12-18
standpoint of such effects that a hard coating film having
good mar resistance due to crystallizability of vinylidene
polyfluoride is obtained, that a good affinity of
vinylidene polyfluoride with polymethylmethacrylate results
good adhesion properties, transparency, and the like, that
chemical resistance is improved, that adhesion properties
between polymethylmethacrylate and adhesive is improved, and
that an ultraviolet light absorber insoluble in. an organic
solvent or a component added in a large amount may
arbitrarily be added.
The transparent film layer is such that the outer layer
has a film thickness in the range of 2 to 50 ~e m,
preferably 3 to 20 ~u m, the inner layer has a film
thickness in the range of 10 to 500 ~ m, preferably 30 to 80
,u m, and a total film thickness of both outer and inner
layers is in the range of 12 to 200 ~u m, preferably 33 to
100 ~u m. An outer layer having a film thickness less than 2
~u m undesirably reduces weather resistance, solvent
resistance, chemical resistance, etc. On the other hand, an
outer layer having a film thickness more than 50 ~e m
reduces transparency, etc. An inner layer having a film
thickness less than 10 ~ m may soften the film, resulting
in reducing coating workability and in making handling
difficult. On the other hand, an inner layer having a film
thickness 500 ~ m may undesirably reduce fabricating
properties.
In the third aspect of the preseri~t invention, the
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CA 02450035 2003-12-18
decorative film may be prepared, for example, by a process
which comprises coating a pigmented coating composition onto
a transparent film to form a pigmented layer and to prepare
a laminate film of the transparent film and the pigmented
layer.
The injection-molded part of the present invention may
be prepared by subjecting a decorative film and a plastic
material to a co-extruding injection molding so that the
surface of a plastic film layer in the decorative film may
contact with the outer surface of a plastic molded product.
In the present invention, an injection molding process
comprises setting the above decorative film within a convex
or concave mold, injecting a heated and melted plastic
material onto the decorative film set as above to be filled
with the plastic material, followed by cooling and removing
the plastic material as a molded part. The decorative film
to be set within the mold may preferably be set so that a
primer layer, topcoatfng layer or transparent film layer in
the decorative film may contact with an inner surface of
the mold, and that a plastic film layer may contact with a
plastic surface. On injecting the heated and melted
plastic material onto the decorative sheet set within the
mold, the heated and melted plastic material may be filled
in the direction of the surface of the plastic layer in the
decorative film so that the melted plastic material may not
be filled between the surface of the mold and the surface
of the decorative film. The decorative film may have such
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CA 02450035 2003-12-18
a size as to corresponding to a total or part of the inner
surface of the mold. That is, variation in size of the
decorative film makes it possible to form the decorative
film onto the total or part of the surface of the plastic
molded part. The decorative film may also be formed by a
process which comprises subjecting the decorative film to a
preliminary fabrication so as to contact with a concave,
inner surface of the mold, followed by setting the
fabricated decorative film so that the surface of the primer
layer or transparent film layer in the decorative film may
be faced and contacted with the concave inner surface of the
mold, injecting the heated and melted plastic material into
the mold to be filled, and molding to form a decorative
film melted and adhered onto the surface of the plastic
molded product. The preliminary fabrication may be carried
out, for example, by heating the decorative film at such a
temperature as to be softened and fabricated, followed by
applying onto the concave or convex surface of the mold
while pressing.
The plastic material may include ones known in the art
without particular limitations, for example, polyethylene,
polypropylene, polyisobutylene, polybutadiene, polystyrene,
polychloroprene, polyvinyl chloride, polyvinyl acetate,
nylon, acrylic resin, polycarbonate, cellulose,
polyethylene, terephthalate, polyacetal, AS resin, ABS
resin, glass fiber-reinforced resins prepared by mixing
glass fiber with the above, and the like. Of these,
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CA 02450035 2003-12-18
f
polyolefin based resins are preferable, and polypropylene
based resins are more preferable.
The plastic material may optionally contain known
additives such as coloring agent, fillers, plasticizers,
heat stabilizers and the like.
A molding temperature may arbitrarily be selected
depending on kinds of decorative films and plastic
materials, but desirably is in such ranges that melting
temperatures of plastics are in the range of about 180 to
250 ~ , preferably about 180 to 230 ~ , and mold temperatures
are in the range of about 30 to 70 ~ , preferably about 40 to
50~ .
In the first and second aspects of the present
invention, in the case where a topcoating composition has
not been coated, a topcoating composition may be coated onto
the surface of the primer layer in an injection-molded
product. The topcoating composition may include a room
temperature-drying type resin coating composition, a curable
type resin coating composition curable at room temperature
or by heating at a temperature in the range of 140 >r or
lower, and an actinic radiation-curable type resin coating
composition. The normal temperature-drying type resin
coating composition may include, for example, acrylic
lacquer and the like. The curable type resin coating
composition may include, for example, resin coating
compositions prepared by mixing a base resin consisting of
polyol resin such as vinyl resin, polyester resin, silicone
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CA 02450035 2003-12-18
resin, fluorocarbon resin and the like with a crosslinking
agent such as (blocked)polyisocyanate compound, amino resin,
alkoxysilane group-containing compound and the like; resin
coating compositions prepared by mixing resins containing
alkoxysilane group, hydroxyl group and epoxy group, and
unsaturated resins such as vinyl resin, polyester resin,
silicone resin and the like with a peroxide catalyst such
as butyl peroxide and the like; and the like. The actinic
radiation-curable type resin coating composition may
include, for example, resin coating compositions containing
the above unsaturated resins optionally further containing
unsaturated monomer such as (meth)acrylate, styrene, (poly)
ethylene glycol di(meth)acrylate and the like; and the
like.
In addition to the above resin components, the
topcoating composition may optionally contain, for example,
organic solvents, color pigments, fillers, flowability
controlling agents, curing catalysts, ultraviolet light
absorbers and the like. The topcoating composition may
coated by one coat coating, metallic base caat/clear coat
multilayer finish coating, etc. The topcoating film
desirably has such coating film thickness that one coat has
a film thickness in the range of about 10 to 80 ,u m, and the
multilayer coating finishing has a base coat film thickness
in the range of about 10 to 50 ~u m, and a clear coat film
thickness in the range of about 20 to 80 ~ m.
The injection-molded part of the present invention may
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CA 02450035 2003-12-18
has uses without particular limitations, but shows good
properties in molding and fabricating properties, finished
appearance, durability, adhesion properties to the pot
coating composition, and the like, and is particularly
useful as automobile parts such as a bumper, side mirror,
side lace and the like.
Firstly the present invention makes it possible to
provide a decorative film for use in plastics molding,
capable of being uniformly and easily joined onto a plastic
molded product having a curved surface area and showing
good adhesion properties to both plastic material and
topcoating film and good finished appearance.
Secondary, the present invention makes it possible to
provide a decorative film for use in plastics molding,
capable of being uniformly and easily joined onto a plastic
molded product having a curved surface area, showing good
adhesion properties to both plastic material and topcoating
film, good finished appearance and electrostatic coating
workability, particularly high electrostatic coating
efficiency of metallic coating composition and high
electrostatic coating efficiency of clear coating
composition.
Thirdly, the present invention makes it possible to
provide a decorative film for use in plastics molding,
capable of being uniformly and easily joined onto a plastic
molded product having a curved surface area, and showing
good adhesion properties to plastic material and good
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CA 02450035 2003-12-18
adhesion properties between a transparent film and a
pigmented layer.
. Fourthly, the present invention makes it possible to
provide a plastic molded part showing good finished
appearance.
The present invention is explained more in detail by
the following Examples.
Example 1
Preparation Example 1 (Preparation of Primer)
A primer was prepared by mixing and dispersing 60 parts
by weight of a polyester resin (phthalic acid/
hexahydrophthalic acid/adipic acid/1,6-hexane
diol/trimethylol propane = 0.1810.46/0.3/0.2/0.1 mole,
hydroxyl number: 103 KOH mglg, dibasic. acid ratio: 0.94),
parts by weight of Superchlon 1436 (trade name, marketed
by Nippon Paper Industries Co:, Ltd.), 50 parts by weight
of CAB551-0.2 (trade name, marketed by Eastman Chemical
Company), 50 parts by weight of Taibake CR93 (trade name,
titanium dioxide pigment), 120 parts by weight of ethyl
acetate, and 0.3 equivalent (hydroxyl group of polyester
resin/NCO) of Duranate E500u-90T (trade name, marketed by
Asahi Chemical Industry Co., Ltd., polyisocyanate compound).
Preparation Example 2 (Preparation of Decorative Film)
A primer prepared in Preparation Example 1 was coated
by use of a knife coater onto one side of PPS-C (trade
name, Cedam Co., Ltd., polypropylene based resin film, film
thickness: 200 a m), followed by drying at 801r for 30
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CA 02450035 2003-12-18
minutes to prepare a decorative sheet having a primer layer
of 25 ~ m in thickness, and applying a releasable film
(silicone-treated polyethylene terephthalate, thickness; 50
a m) onto the surface of the primer layer in the decorative
sheet to obtain a decorative film. A static glass
transition temperature, elongation and tensile strength of
the primer layer formed as above are shown in Table 1. Test
results of anti-tack properties, adhesion properties and
adhesion properties to topcoating for the decorative film
obtained as above are shown in Table 1.
In Table 1, anti-tack properties, adhesion properties,
adhesion properties A to topcoating, adhesion properties B
to topcoating, and molding properties mean as follows
respectively.
Anti-Tack Properties:
Primer coating films were lapped together, followed by
applying a load of 6 g/cm2, leaving to stand at 20>~ for one
hour, and examining adhesion properties to evaluate as
follows. 3: Easily separable without being adhered; 2:
adhered; 1~. non-separable due to adhesion.
Adhesion Properties (Adhesion properties between polyolefin
base material and primer coating film):
A coating film was cut so as to reach a substrate with a
sharp knife to form 100 squares having a size of t x 1 mm
respectively, followed by adhering an adhesive cellophane
tape onto the surface of the squares, and strongly
separating the tape to evaluate conditions on the surface
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CA 02450035 2003-12-18
with the squares as follows.
3: No squares separated; 2: some squares are separated; 1:
many squares are separated.
Adhesion Properties A to Topcoating:
Soflex 1410 (trade name, marketed by Kansas Paint Co.,
Ltd., melamine-curing type acrylic resin based metallic base
coating composition) was coated so as to be a dry film
thickness of 20 ~ m by spray coating, followed by
preliminarily heating, coating Soflex 1630 Clear (trade
name, marketed by Kansas Paint Co., Ltd., melamine-curing
type acrylic resin based clear coating composition) so as to
be a dry film thickness of 30 ~ m by spray coating, heat
curing at 120>r for 30 minutes, and subjecting to the same
adhesion properties test as above to evaluate as follows.
3: No separation between primer coating film and topcoating
film was observed; 2: some separation therebetween was
observed; 1: considerable separation therebetween was
observed.
Adhesiom Properties B to Topcoating:
A Softex 400H (trade na~e, marketed by Kansas Paint
Co., Ltd., i:socyanate-curing type acrylic resin based
metallic base coating composition) was coated so as to be a
dry film thickness of 20 a m by spray coating, followed by
preliminarily heating, coating Softex 500H Clear (trade
name, marketed by Kansas Paint Co., Ltd., isocyanate-curing
type acrylic resin based clear coating composition) so as to
be a dry film thickness of 30 ~ m by spray coating, heat
-45-
CA 02450035 2003-12-18
curing at 80 ~ for 20 minutes, and subjecting to the same
adhesion properties test as above to evaluate as~follows.
3: No separation between primer coating film and topcoating
film was observed; 2: some separation therebetween was
observed; 1: considerable separation therebetween was
observed.
Molding Properties:
The decorative film obtained as above was set on an
inner surface of an injection mold capable of molding in a
cup type (maximum degree of deformation: two fold) so that
the primer layer of the decorative film can be contacted
with the inner surface of the mold, followed by injecting
under pressure the polypropylene heated and melted at about
230 ~ in an injection molding machine onto the surface of
the polypropylene based resin film layer in the decorative
film, cooling the mold, and removing a molded product from
the mold to obtain a polypropylene molded~part.
Conditions in curved surface area and plane surface
area of the polypropylene molded part obtained as above
were evaluated. as follows.
3: No deffects such as reduction in gloss, peeling, cracks
were observed, showing good appearance; 2: reduction in
gloss was observed; 1: reduction in gloss, peeling, cracked
were observed.
Example 2
Procedures of Example 1 were duplicated except that the
primer listed in Table 1 was used. Results are shown in
CA 02450035 2003-12-18
Table 1.
Example 3
Procedures of Example 1 were duplicated except that the
primer listed in Table 1 was used. Results are shown in
Table 1.
Comparative Example 1
Procedures of Example 1 were duplicated except that the
primer listed in Table 1 was used. Results are shown in
Table 1.
Comparative Example 2
Procedures of Example 1 were duplicated except that the
primer listed in Table 1 was used. Results are shown in
Table 1.
-a~-
CA 02450035 2003-12-18
a
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-aa-
CA 02450035 2003-12-18
Example 4
Preparation Example 3 (Preparation of Primer ~
A primer was prepared by mixing and dispersing 54 parts
by weight of polyester resin (phthalic acid/
hexahydrophthalic acid/adipic acid/1,6-hexane
diol/trimethylol propane = 0.18/0.46/0.310.2/0.1 mole,
hydroxyl number: 103 KOH mg/g, dibasic acid ratio: 0.94),
13 parts by weight of Superchlon 1436 (trade name, marketed
by Nippon Paper Industries Co., Ltd.), 33 parts by weight
of CAB551-0.2 (trade name, marketed by Eastman Chemical
Company), 20 parts by weight of Tanbake CR93 (trade name,
titanium dioxide pigment), 80 parts by weight of Dentall WK-
500 (trade name, marketed by Otsuka Chemical Co., Ltd.,
fiber-shaped electrically conductive pigment, average fiber
length: 5-15 ~u m, average fiber diameter: 0.1-0.5 ,u m),
120 parts by weight of ethyl acetate, and 0.3 equivalent
(NCO in polyester resin/hydroxyl group) of Duranate E5004-
90T (trade name, marketed by Asahi Chemical Industry Co.,
Ltd., p.olyisocyanate compound).
Preparation Example 4 (Preparation of Decorative Film)
The above primer was coated by use of a knife coater
onto one side of PPS-C (trade name, marketed by Cedam Co.,
Ltd., polypropylene based resin film, thickness 200,u m),
followed by drying at 80>r for 30 minutes to prepare a
decorative film having a primer layer of 25 ~ m, and
applying a releasable film (silicone-treated, non-
crystalline polyethylene terephthalate, thickness 50 ~u m)
-49-
CA 02450035 2003-12-18
onto the surface of the primer layer obtained as above to
prepare a decorative film.
A static glass transition temperature, elongation and
tensile strength of the primer layer formed as above are
shown in Table 2. The anti-tack properties, adhesion
properties and adhesion properties to topcoating of the
decorative film obtained as above examined, and results are
shown in Table 2.
In Table 2, anti-tack properties, adhesion properties,
adhesion properties A to topcoating, adhesion properties B
to topcoating and molding properties have the same meanings
as in Table 1 respectively.
In Table 2, electrostatic coating efficiency of
metallic base coating composition, electrostatic coating
efficiency of clear coating composition and lightness of
primer coating film mean as follows respectively.
Electrostatic Coating Efficiency of Matallic Base Coating
Composition:
Soflex 1410 (trade name, marketed by Kansai Paint Co.,
Ltd., melamine-curing type acrylic resin based metallic. base
coating composition) was coated onto the surface of the
primer layer in the above decorative film so as to be a dry
film thickness of 20 ~u m by electrostatic spray coating,
followed by heat curing at 120 ~ for 30 minutes.
The electrostatic coating was carried out by use of an
air spray electrostatic coating machine with REA gun,
marketed by Landsberg Co., Ltd. under the conditions of a
-50-
CA 02450035 2003-12-18
f
coating area of t00cm x 100cm, coating voltage of -60V, and
coating amounts of 300 to 400 g/min.
Coating Efficiency = (part by weight of solid content
of the coating composition which has coated and formed a
film part by weight of solid content of the coating
composition which was coated) x 100
Electrostatic Coating Efficiency of Clear Coating
Composition:
Soflex 1630 Clear (trade name, marketed by Kansai Paint
Co., Ltd., melamine-curing type acrylic resin based clear
coating composition) was coated onto the surface of-the
above metallic coating film so as to be a dry film
thickness of 30 ~ m by electrostatic coating, followed by
heat curing at 120 ~ for 30 minutes.
The electrostatic coating was carried out by use of a
rotary Bell type electrostatic coating machine marketed by
Landsberg Co., Ltd., Microbell, under the conditions of a
coating area of 100 cm x 100cm, coating voltage of -90V,
and coating amounts of 200 to 300 g/min. The coating
efficiency was determined in the same manner as above.
Lightness of Primer Coating Film:
The surface of the coating film was visually evaluated
as follows.
4: white and good; 3: lightly gray and good; 2: a little
dark gray; 1: gray.
Surface Resistivity of Primer Coating Film:
The surface resistivity was measured by use of a high
-51-
CA 02450035 2003-12-18
resistance tester model TR-3 (marketed by IDX Corporation).
Example 5
Procedures of Example a were duplicated except that
Taybake CR93 and Dentall WK-500 were used in amounts as
listed in Table 2 respectively. Results are shown in Table
2.
Example 6
Procedures of Example 4 were duplicated except that
Taybake CR93 and Dentall WK-500 were used in amounts as
listed in Table 2 respectively. Results are shown in Table
2.
Comparative Example 3
Procedures of Example 4 were duplicated except that
Taybake CR93 and Dentall WK-500 were used in amounts as
listed in Table 2 respectively. Results are shown in Table
2.
-52-
CA 02450035 2003-12-18
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-53-
CA 02450035 2003-12-18
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Example 7
Preparation Example 5 (Preparation of Decorative Film)
Acrylic #2000 Silver metallic (trade name, marketed by
Kansai Paint Co., Ltd., acrylic lacquer, elongation 8%,
tensile strength 3.7 kgf/mm2, glass transition temperature
78'c ) was coated onto the surface of Kureha KFC film FT-50Y
(trade name, marketed by Kureha Chemical Industry. Cc., Ltd.,
film thickness 50,~ m, vinylidene polyfluoride layer 5~
m/polymethyl methacrylate layer 4.5 ~ m) by spay spay
coating, followed by heating and drying at 45~ for 60
minutes to form a pigmented layer.
MHS-3356 (trade name, marketed by Toyo-Morton, Ltd.,
hot lacquer type heat sealing agent, ethylene vinyl acetate
resin) was coated onto one side of PPS-C (trade name,
marketed by Cedam Co., Ltd., prolypropyrene based resin
film, thickness 200 a m) so as to be a dry film thickness of
to 20 ~ m to form a film having a heat seal layer,
followed by setting so that the pigmented layer may be
folded on the heat seal layer, heating under pressure, and
laminating to prepare a decorative film outwardly and
successively laminating PS-C (plastic film layer), heat
seal layer (adhesive layer), pigmented layer, and Kureha
KFC film FT-50Y (transparent layer).
Test results of the performances and molding properties
of the decorative film obtained in Example 7 are shown in
Table 3.
Table 3
-54-
CA 02450035 2003-12-18
Example Example Comp. Ex
~ 8 4
Finished 4 4 3
appearance
surface H HB B
hardness
adhesion 3 3 3
Perfor properties
mance
water
resistance
appearance 3 3 3
adhesion properties 3 3 2
molding properties 4 4 3
solvent resistance 3 2 2
In Table 3, adhesion properties and molding properties
are the same as in Table 1. Adhesion properties in water
resistance test was carried out after water resistance test.
In Table 3, finished appearance, surface hardness,
water resistance, and solvent resistance mean as follows
respectively.
Finished Appearance:
Finished appearance of the decorative film was visually
evaluated by glass, bubbling, smoothness, shrinkage,
metallic feeling, etc. as follows. 4: good; 3: a little
poor but good, 2; poor; 1: seriously poor.
Surface Hardness:
Surface hardness of the transparent film was measured
according to pencil scratching test defined in JIS K-5400
8.4.2 (1990). Evaluation was made depending on development
-55-
CA 02450035 2003-12-18
r .. -.
of mars.
Water Resistance:
The decorative film was dipped into water at 40 ~ for 7
days to evaluate the condition of the film surface as
follows.
Appearance:
3: nothing abnormal; 2: some blisters developed; 1:
blisters seriously developed.
Solvent Resistance:
A gauze impregnated with acetone solvent was place on
the surface of the transparent film, followed by
reciprocally rubbing 20 times strongly pressing the gauze
with the finger for testing. After testing, the film
- surface was visually evaluated as follows.
3: no changes in glossiness; 2: glossiness disappeared; 1:
dissolved.
Example 8
Procedures of Example 7 were duplicated except that the
decorative film prepared in Preparation Example 6 was used.
Results are shown in Table 3.
Preparation Example 6 (Preparation of Decorative Film)
A decorative film was prepared in the same manner as in
Preparation Example 5 except that Denka DX Film DX-14S
(trade name, marketed by Denki Kagaku Kogyo Kabushiki
Kaisha, film thickness 50 ,u m, upper layer vinylidene
polyfluoride/polymethyl methacrylate = 8/2 weight ratio, 17
- ~e m; lower layer polymethyl methacrylate/vinylidene
-56-
CA 02450035 2003-12-18
,. ~. ...
polyfluoride = 2I8 weight ratio, 33 ~ m} was used in place
of Kureha KFC.Film FT-50Y.
Comparative Example 4
Procedures of Example 7 were duplicated except that a
casting film prepared by dissolving vinylidene
polyfluoride/polymethyl methacrylate = 8/2 (weight ratio)
into dimethyl aceto-amide solution, followed by casting onto
a glass plate, and drying to form a casting film having a
thickness of about 50~ m was used as the transparent film.
Results are shown in Table 3.
_57-
