U.S. patent application number 09/750687 was filed with the patent office on 2001-08-09 for photosensitive compositions and pattern formation method.
Invention is credited to Tagoshi, Hirotaka, Tochizawa, Noriaki, Watanabe, Masaharu, Yamaguchi, Tetsuhiko.
Application Number | 20010012597 09/750687 |
Document ID | / |
Family ID | 22573410 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010012597 |
Kind Code |
A1 |
Watanabe, Masaharu ; et
al. |
August 9, 2001 |
Photosensitive compositions and pattern formation method
Abstract
Photosensitive compositions prepared without use of a chromium
compound. The compositions exhibit high resolution and satisfactory
sensitivity, and do not cause environmental pollution. The
photosensitive compositions contain a water-soluble azide compound
which serves as a photocrosslinking agent and
poly(N-vinylacetamide) that is photocrosslinkable in the presence
of the water-soluble azide compound.
Inventors: |
Watanabe, Masaharu; (Chiba,
JP) ; Tochizawa, Noriaki; (Chiba, JP) ;
Tagoshi, Hirotaka; (Chiba, JP) ; Yamaguchi,
Tetsuhiko; (Kanagawa, JP) |
Correspondence
Address: |
SUHRUE, MION, ZINN, MACPEAK & SEAS, PLLC
2100 Pennsylvania Avenue, N.W.
Washington
DC
20037
US
|
Family ID: |
22573410 |
Appl. No.: |
09/750687 |
Filed: |
January 2, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09750687 |
Jan 2, 2001 |
|
|
|
09159649 |
Sep 24, 1998 |
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Current U.S.
Class: |
430/167 ;
430/196; 430/197; 430/325; 430/7 |
Current CPC
Class: |
G03F 7/0125
20130101 |
Class at
Publication: |
430/167 ;
430/196; 430/197; 430/7; 430/325 |
International
Class: |
G03F 007/008; G03F
007/30 |
Claims
What is claimed is:
1. A photosensitive composition comprising a water-soluble azide
compound serving as a photocrosslinking agent and
poly(N-vinylacetamide) that is photocrosslinkable in the presence
of the water-soluble azide compound.
2. A photosensitive composition according to claim 1, which further
contains another water-soluble polymer that is photocrosslinkable
in the presence of the above-described water-soluble azide
compound.
3. A photosensitive composition according to claim 2, wherein said
another water-soluble polymer comprises at least one species
selected from the group consisting of polyvinylpyrrolidone,
acrylamide-diacetoneacrylamide copolymers,
poly(N,N-dimethylacrylamide), and N,N-dimethylacrylamide-acry-
lamide copolymers.
4. A photosensitive composition according to any one of claims 1
through 3, which further contains additives and at least one
species of water-soluble polymers.
5. A pattern formation method comprising forming a photosensitive
composition layer on a substrate by applying a photosensitive
composition according to any of the first through fourth modes; to
a substrate performing a pattern exposure on the photosensitive
composition layer; and subsequently developing the resulting
exposed layer with water or an aqueous developer.
6. A pattern formation method according to claim 5, wherein the
photosensitive composition further contains another water-soluble
polymer that is photocrosslinkable in the presence of the
above-described water-soluble azide compound.
7. A pattern formation method according to claim 6, wherein said
another water-soluble polymer comprises at least one species
selected from the group consisting of polyvinylpyrrolidone,
acrylamide-diacetoneacrylamide copolymers,
poly(N,N-dimethylacrylamide), and N,N-dimethylacrylamide-acry-
lamide copolymers.
8. A pattern formation method according to claim 5, wherein the
photosensitive composition further contains additives and at least
one species of water-soluble polymers.
9. A pattern formation method according to any one of claims 5
through 8, wherein the substrate is the inner surface of the face
plate of a color cathode-ray tube.
10. A photosensitive composition for the formation of a black
matrix, which composition is used for the formation of a black
matrix of color cathode-ray tubes and which contains a
water-soluble azide compound serving as a photocrosslinking agent
and a water-soluble polymer which is photocrosslinkable in the
presence of the water-soluble azide compound, wherein the
photocrosslinkable water-soluble polymer predominantly contains
poly(N-vinylacetamide) and further contains another water-soluble
polymer having reciprocity-law failure characteristics more
prominent than those of the corresponding
poly(N-vinylacetamide).
11. A photosensitive composition according to claim 10, wherein
said another water-soluble polymer comprises at least one species
selected from the group consisting of polyvinylpyrrolidone,
acrylamide-diacetoneacrylamide copolymers,
poly(N,N-dimethylacrylamide), and N,N-dimethylacrylamide-acrylamide
copolymers.
12. A photosensitive composition for the formation of a phosphor
pattern, wherein said composition contains a water-soluble azide
compound serving as a photocrosslinking agent; a water-soluble
polymer which is photocrosslinkable in the presence of the
water-soluble azide compound; and a phosphor; and which is prepared
by dissolving or dispersing these in an aqueous medium, wherein the
photocrosslinkable water-soluble polymer contains
poly(N-vinylacetamide).
13. A photosensitive composition for the formation of a phosphor
pattern according to claim 12, which further contains at least one
species selected from among saponified products of polyvinyl
acetate or acrylic emulsions.
14. A photosensitive composition for the formation of a color
filter, wherein said composition contains a water-soluble azide
compound serving as a photocrosslinking agent; a water-soluble
polymer which is photocrosslinkable in the presence of the
water-soluble azide compound, and a pigment; and which is prepared
by dissolving or dispersing these in an aqueous medium, wherein the
photocrosslinkable water-soluble polymer contains
poly(N-vinylacetamide).
15. A photosensitive composition for the formation of a color
filter according to claim 14, which further contains at least one
species selected from among saponified products of polyvinyl
acetate or acrylic emulsions.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to photosensitive
compositions, more particularly to water-soluble photosensitive
compositions suitably used for the formation of color filters,
phosphor patterns, and black matrices of color cathode-ray
tubes.
[0003] 2. Description of Conventional Art
[0004] Conventionally, negative-type photoresists used for the
formation of black matrices and phosphor patterns of color
cathode-ray tubes, etc., have made use of resists composed of a
water-soluble polymer such as polyvinyl alcohol and a bichromate
salt (called PVA-ADC-based resists). Photoresists of this type have
a fundamental disadvantage in that they require a special treatment
facility for preventing environmental pollution, which is otherwise
caused due to the presence of bichromate salts.
[0005] As photoresists that are free from the above problem, there
have been known photosensitive compositions containing a
water-soluble diazide compound, e.g., sodium
4,4'-diazidostilbene-2,2'-disulfonate (hereinafter abbreviated
DAS), which serves as a photocrosslinking agent, and a
water-soluble polymer that is photocrosslinkable in the presence of
the water-soluble diazide compound. For example, there are proposed
photosensitive compositions containing, as polymer matrices, vinyl
alcohol-maleic acid copolymers or salts thereof (Japanese Patent
Application Laid-Open (kokai) No. 48-97602), vinyl
alcohol-acrylamide copolymers (Japanese Patent Application
Laid-Open (kokai) No. 48-97603), or water-soluble polyvinylbutyrals
(Japanese Patent Application Laid-Open (kokai) No. 48-98905). In
practice, however, these compositions cannot be used because of
their low sensitivity. At present, known compositions having
sufficient sensitivity in practice include those containing
polyvinylpyrrolidone (hereinafter abbreviated PVP) and a
water-soluble diazide compound serving as an additive (hereafter,
compositions of this type will be referred to as PVP-DAS-based
resists; see, for example, Japanese Patent Application Laid-Open
(kokai) No. 48-90185), as well as those containing an
acrylamide-diacetoneacrylamide copolymer (hereinafter abbreviated
PAD) and water-soluble diazide serving as an additive (hereafter,
compositions of this type will be referred to as PAD-DAS-based
resists; see, for example, Japanese Patent Application Laid-Open
(kokai) No. 50-33764).
[0006] When used for the formation of black matrices of color
cathode-ray tubes, PVA-ADC-based resists have a drawback of poor
resolution, in addition to the aforementioned problem of
environmental pollution, due to low oxygen permeability and lack of
reciprocity-law failure characteristics. In contrast, when
PVP-DAS-based resists are used, due to their excessively high
oxygen permeability, proper sensitivity cannot be obtained unless
the thickness of coating film is increased, which in turn reduces
resolution. PAD-DAS-based resists, on the other hand, are endowed
with excellent sensitivity and resolution, but after they have
undergone formation of resist patterns and coating with graphite
they provide poor etching characteristics, and, depending on the
type of graphite, etching cannot be effected.
[0007] With regard to use for the formation of phosphor patterns,
PVA-ADC-based resists are unsatisfactory in terms of both
environmental pollution and sensitivity, and in addition, chromium
oxide which remains after firing degrades the luminance of the
phosphor. In this respect, PVP-DAS-based resists and PAD-DAS-based
resists have drawbacks in terms of sensitivity, and therefore
cannot be used.
[0008] Meanwhile, there are known non-chromium resists which are
used for the formation of phosphor patterns and which contain as a
photosensitive unit a photosensitive resin obtained through a
condensation reaction between unmodified polyvinyl alcohol and a
quaternary ammonium salt (e.g., a styrylpyridinium salt or a
styrylquinolinium salt) (Japanese Patent Application Laid-Open
(kokai) Nos. 55-23163, 55-62905, and 56-11906). However, these
resists are also unsatisfactory in terms of resolution.
[0009] As described above, there exist no conventional photoresists
that simultaneously satisfy requirements with respect to
environmental pollution, sensitivity, and resolution. Therefore,
there is still need for novel resist materials that exhibit
excellent characteristics.
SUMMARY OF THE INVENTION
[0010] In view of the foregoing, an object of the present invention
is to provide photosensitive compositions which do not cause
environmental pollution and which exhibit high resolution and
satisfactory sensitivity.
[0011] In order to overcome the above-described drawbacks, a first
mode of the present invention is directed to a photosensitive
composition which contains a water-soluble azide compound serving
as a photocrosslinking agent and poly(N-vinylacetamide) that is
photocrosslinkable in the presence of the water-soluble azide
compound.
[0012] In a second mode of the present invention, the
photosensitive composition according to the first mode further
contains another water-soluble polymer that is photocrosslinkable
in the presence of the above-described water-soluble azide
compound.
[0013] In a third mode of the present invention, the photosensitive
composition according to the second mode contains the water-soluble
polymer which comprises at least one species selected from the
group consisting of polyvinylpyrrolidone,
acrylamide-diacetoneacrylamide copolymers,
poly(N,N-dimethylacrylamide), and N,N-dimethylacrylamide-acry-
lamide copolymers.
[0014] In a fourth mode of the present invention, the
photosensitive composition according to any of the first through
third modes further contains additives and at least one species of
water-soluble polymers.
[0015] In a fifth mode of the present invention, there is provided
a pattern formation method which comprises forming a photosensitive
composition layer on a substrate by applying a photosensitive
composition according to any of the first through fourth modes; to
a substrate performing a pattern exposure on the photosensitive
composition layer; and subsequently developing the resulting
exposed layer with water or an aqueous developer.
[0016] In a sixth mode of the present invention, the
above-described substrate employed in the method according to the
fifth mode serves as an inner surface of a face plate of a color
cathode-ray tube.
[0017] A seventh mode of the present invention is directed to a
photosensitive composition for the formation of a black matrix,
whrein the composition is used for the formation of a black matrix
of color cathode-ray tubes and which contains a water-soluble azide
compound serving as a photocrosslinking agent and a water-soluble
polymer which is photocrosslinkable in the presence of the
water-soluble azide compound, wherein the above-described
photocrosslinkable water-soluble polymer predominantly contains
poly(N-vinylacetamide) and further contains another water-soluble
polymer having reciprocity-law failure characteristics more
prominent than those of the corresponding
poly(N-vinylacetamide).
[0018] In an eighth mode of the present invention, the
water-soluble polymer contained in the photosensitive composition
according to the seventh mode is at least one species selected from
the group consisting of polyvinylpyrrolidone,
acrylamide-diacetoneacrylamide copolymers,
poly(N,N-dimethylacrylamide), and N,N-dimethylacrylamide-acrylamide
copolymers.
[0019] A ninth mode of the present invention is directed to a
photosensitive composition for the formation of a phosphor pattern,
wherein the composition contains a water-soluble azide compound
serving as a photocrosslinking agent; a water-soluble polymer which
is photocrosslinkable in the presence of the water-soluble azide
compound; and a phosphor; and which is prepared by dissolving or
dispersing these in an aqueous medium, wherein the above-described
photocrosslinkable water-soluble polymer contains
poly(N-vinylacetamide).
[0020] In a tenth mode of the present invention, the photosensitive
composition for the formation of a phosphor pattern according to
the ninth mode further contains at least one species selected from
among saponified products of polyvinyl acetate or acrylic
emulsions.
[0021] A eleventh mode of the present invention is directed to a
photosensitive composition for the formation of a color filter,
wherein the composition contains a water-soluble azide compound
serving as a photocrosslinking agent; a water-soluble polymer which
is photocrosslinkable in the presence of the water-soluble azide
compound, and a pigment; and which is prepared by dissolving or
dispersing these in an aqueous medium, wherein the above-described
photocrosslinkable water-soluble polymer contains
poly(N-vinylacetamide).
[0022] In a twelfth mode of the present invention, the
photosensitive composition for the formation of a color filter
according to the eleventh mode further contains at least one
species selected from among saponified products of polyvinyl
acetate or acrylic emulsions.
[0023] The present invention provides photosensitive compositions
which do not cause environmental pollution and which exhibit high
resolution and satisfactory sensitivity, without use of a chromium
compound.
[0024] The present invention was accomplished based on the finding
that satisfactory photosensitive compositions are obtained through
use of poly(N-vinylacetamide)(called p-NVA), which is not employed
in use of this field, and a water-soluble azide compound serving as
a photocrosslinking agent.
[0025] The p-NVA which may be used in the present invention
preferably has a molecular weight of 100,000-4,000,000 (GPC (gel
permeation chromatography) analysis: reduced as pullulan) and a
viscosity (300-70,000 cp (7% solution, 25.degree. C.)) in view of
sensitivity, film-formability, etc.
[0026] The water-soluble azide compounds which may be used in the
present invention include, but are not limited to, compounds
represented by the formulas described below. 1
[0027] wherein X represents lithium, sodium, potassium, ammonium,
monoalkylammonium, dialkylammonium, trialkylammonium, or
tetraalkylammonium. Furthermore, the water-soluble azide compounds
include polymers having a sulfonic acid group or a sulfonate salt
group, and an azido group that are described, for example, in
Japanese Patent Application Laid-Open (kokai) Nos. 51-4956,
2-173007, 2-92905, 2-204750, 5-11442, 5-67433, 5-113661, 6-32823,
and 6-345718. Among the above-described water-soluble azide
compounds, those having two or more azide groups in the molecule
have particularly good photocrosslinkability. These compounds may
be used in combination of two or more species. These water-soluble
azide compounds are preferably used in an amount of 2-50 wt. %
based on the copolymers. When the content of the water-soluble
azide compounds is less than 2%, poor sensitivity results, whereas
when the content is in excess of 50%, physical properties of the
coating film become poor, both cases are disadvantageous.
[0028] The photosensitive compositions of the present invention may
be prepared by dissolving or dispersing in a water-based solvent
the aforementioned p-NVA, the water-soluble azide compounds, and
additives in accordance with use. In this case, water is generally
used as the solvent, and to water, there may be added a
water-soluble solvent, in an amount of 50 wt. % or less. Examples
of such water-soluble solvents include methyl alcohol, ethyl
alcohol, isopropyl alcohol, acetone, tetrahydrofuran, dioxane,
dimethylacetamide, N-methylpyrrolidinone, ethylene glycol monoethyl
ether, ethylene glycol monomethyl ether, and propylene glycol
monomethyl ether.
[0029] As described above, the photosensitive compositions of the
present invention may further contain, in addition to the
aforementioned p-NVA and water-soluble azide compounds,
water-soluble polymers which are crosslinkable in the presence of
the above-described water-soluble azide compound. Examples of such
crosslinkable water-soluble polymers include polyvinylpyrrolidone
and copolymers thereof, and at least one species selected from the
group consisting of acrylamide-diacetoneacrylamide copolymers,
poly(N,N-dimethylacrylamide), and N,N-dimethylacrylamide-acry-
lamide copolymers.
[0030] To the photosensitive compositions of the present invention,
there may be added a water-soluble polymer which may exhibit
compatibility to the photosensitive compositions of the present
invention in order to further improve the coatability, sensitivity,
developability, etc. thereof. However, since addition in an excess
amount affects the excellent physical properties of the
photosensitive compositions of the present invention, the amount of
the water-soluble polymer is preferably 70 wt. % or less based on
the total amount of polymers.
[0031] Examples of such a water-soluble polymer include a
saponified product of polyvinyl acetate, gelatin, a methy vinyl
ether-maleic anhydride copolymer, a vinyl alcohol-maleic acid
copolymer, a water-soluble cellulose derivative, and polyethylene
oxide.
[0032] The saponified product of polyvinyl acetate which may be
used in the present invention comprises polyvinyl alcohol, and
vinyl alcohol-another vinyl compound water-soluble copolymer.
Examples of the saponified product of polyvinyl acetate include a
saponified product of polyvinyl acetate modified with a hydrophilic
group, an anion, a cation, an amide or a reactive group such as an
acetoacetyl group.
[0033] Preferably, the saponified product of polyvinyl acetate has
an average polymerization degree of 200-5,000 and a saponification
degree of 60-100%, for example. When the average polymerization
degree is less than 200, obtaining the sufficient sensitivity is
difficult, whereas when it is in excess of 5,000, the viscosity of
a solution of the photosensitive resin increases, often
disadvantageously resulting in poor coating charactaristics.
Furthermore, when the concentration is decreased in order to reduce
the viscosity, obtaining the desired coating film thickness is
difficult. When the saponification degree is less than 60%,
obtaining sufficient water-solubility and water-developability is
difficult.
[0034] The water-soluble copolymer of vinyl alcohol and another
vinyl compound which may be used has an average polymerization
degree of 200-5,000, for example. Examples of the vinyl monomers to
be copolymerized with vinyl alcohol include N-vinylpyrrolidone and
acrylamide.
[0035] Additives such as ethylene glycol, sorbitol, and surfactants
may optionally be added to the photosensitive composition of the
present invention in order to improve the coatability and
moisture-retention property of the composition. A silane coupling
agent which serves as an adhesion-accelerator may optionally be
added to the photosensitive composition of the present invention in
order to improve adhesion to a substrate. Examples of the
adhesion-accelerators which may be used include N-.beta.
(aminoethyl)-aminopropylmethyldimethoxysilane and N-.beta.
(aminoethyl)-.gamma.-aminopropyltrimethoxysilane.
[0036] Additives such as a preservative, a defoaming agent, or a
pH-adjusting agent may optionally be added to the photosensitive
composition of the present invention.
[0037] Hydrophobic polymer emulsions may optionally be added to the
photosensitive composition of the present invention in order to
improve the film strength, water resistance, and adhesion to a
variety of substrates. Examples of the hydrophobic emulsions
include a polyvinyl acetate emulsion, a polyacrylic acid ester
emulsion, and a urethane emulsion.
[0038] Further, colorants such as a pigment or a dye may be added
to the photosensitive composition of the present invention in order
to prevent halation induced by exposure or to obtain a colored
image.
[0039] In particular, the colored image obtained by dispersing a
pigment in the photosensitive composition of the present invention
may be applied to a color filter for a liquid crystal display, for
a color cathode-ray tube, and for a plasma display; a color proof
for printing; a secondary original image for printing; etc.
[0040] The above-described photosensitive composition of the
present invention may be processed through, for example, forming a
photosensitive composition layer on a substrate by applying a
photosensitive composition; to a substrate performing a pattern
exposure on the photosensitive composition layer; and subsequently
developing the resulting exposed layer with water or an aqueous
developer.
[0041] Examples of the above-described substrate include an inner
surface of a surface plate of a color cathode-ray tube.
Accordingly, a black matrix, a phosphor pattern, a color filter,
etc. of a color cathode-ray tube may be specifically formed.
[0042] The pattern formation method using the photosensitive
compositions of the present invention will next be described in
detail.
[0043] (1) Step for Forming a Photosensitive Composition Layer on a
Substrate
[0044] No particular limitation is imposed on the substrate which
may be used in the present invention, any substrate to which the
photosensitive composition of the present invention can adhere to
may be used. Examples of the above-described substrate include
glass such as soda glass, SiO.sub.2-treated glass, or ITO-coated
glass; plastic films such as polyester films, polyamide films,
polyvinyl chloride films, and polypropylene films; metal
substrates; metal-laminated plastic sheets and films; metal meshes;
and silicon wafers.
[0045] Example coating methods for the photosensitive composition
of the present invention include spin coating, roll-coater coating,
curtain coating, and applicator coating, which have conventionally
been employed. The coated layer is subsequently dried through a
customary method at a specific temperature, to thereby obtain a
coating film.
[0046] (2) Pattern Exposure Step
[0047] Any customary light source may be used for the exposure of
the above-described coating film of the photosensitive composition
so long as it emits light having a wavelength at which the
water-soluble azide compound can be sensitized. Examples include an
ultra-high-pressure mercury lamp, a high-pressure mercury lamp, a
xenon lamp, a metal halide lamp, and a chemical lamp. Also, there
may be employed any customary exposure method such as the
reduction-projection exposure method, the contact exposure method,
or the proximity exposure method.
[0048] (3) Development Step
[0049] The above-described patternwise irradiated coating film of
the photosensitive composition may be developed by use of water, a
mixture solvent of water-aqueous solvent, or an aqueous solution
containing an acid, an alkali, a buffer, a surfactant, etc.
Examples of the development methods include spray-development,
dipping-development, paddle-development, etc., which are customary
methods.
[0050] As described above, the pattern formation method of the
present invention is particularly advantageously applied to the
inner surface of the face plate of a color cathode-ray tube.
Application of the above-described pattern formation method to the
above-described inner surface of the face plate of a color
cathode-ray tube assures high sensitivity and high resolution, and
therefore high productivity is realized.
[0051] For example, in the case in which the black matrix of a
color cathode-ray tube is formed, graphite is applied onto the
above-described formed pattern and the coated pattern is treated
with an etchant. In this case, a fine black matrix is obtained due
to good etchability of the pattern formed in accordance with the
present invention.
[0052] In the case of formation of a phosphor pattern, the
photosensitive composition of the present invention containing a
phosphor is homogeneously applied onto a substrate on which the
phosphor pattern is formed, e.g., the above-described black matrix
on the inner surface of the face plate of a color cathode-ray tube,
and is then dried. The coated composition is exposed to a UV beam
through a mask having a predetermined pattern, and then developed
with water so that only the exposed parts remain. When phosphors of
red (R), green (G), and blue (B) are used, the above-described
steps are performed three times to thereby complete the phosphor
face.
[0053] In the case of formation of a color filter, the
photosensitive composition of the present invention containing an
inorganic pigment is homogeneously applied onto a substrate on
which the color filter is formed, e.g., the black matrix-equipped
face plate of a color cathode-ray tube, and is then dried. The
coated composition is exposed to a UV beam through a mask having a
predetermined pattern, and then developed with water so that only
the exposed parts remain. When inorganic pigments of red (R), green
(G), and blue (B) are used, the above-described steps are performed
three times to thereby complete the color filter.
[0054] Next will be described the compositions suitable for a
variety of uses when the photosensitive compositions of the present
invention are used.
[0055] First, the reciprocity-law failure characteristics of the
photosensitive compositions for the formation of black matrices of
color cathode-ray tubes is attempted to be enhanced in order to
realize high resolution, since p-NVA used in the present invention
has low oxygen permeability. Therefore, a blend of water-soluble
polymers which have high reciprocity-law failure characteristics
and are photocrosslinkable in the presence of a water-soluble azide
compound, are preferred. As described above, examples of the
water-soluble polymers which are suitably used include
polyvinylpyrrolidone and copolymers thereof,
acrylamide-diacetonacrylamide copolymers, and
poly(N,N-dimethylacrylamide- ), N,N-dimethylacrylamide-acrylamide
copolymers. No particular limitation is imposed on the blend ratio,
and there may be selected a blend ratio that enhances the
resolution of the photosensitive compositions of the present
invention and provides high sensitivity without increasing the
coating film thickness. For example, p-NVA and another polymer may
be blended at a blend ratio of 1:0.1-10.
[0056] Meanwhile, no particular blend of water-soluble polymers
having high oxygen permeability is needed for the photosensitive
compositions of the present invention used for the formation of
phosphor patterns, since p-NVA has suitable reciprocity-law failure
characteristics. As mentioned above, a photosensitive composition
having satisfactorily high resolution and sensitivity is obtained
by simply dispersing a predetermined phosphor. For example, a
saponified product of polyvinyl acetate and an acrylic emulsion may
be used.
[0057] No particular limitation is imposed on the phosphor used in
this case, and any phosphor which is used in a phosphor-containing
display device may be used.
[0058] In the compositions of the present invention, preferred
proportions of the above-described components are p-NVA (+another
polymer):crosslinking agent:phosphor=100:3-30:300-3000.
[0059] When the photosensitive compositions of the present
invention used for the formation of color filters are prepared no
particular blend of water-soluble polymers having high oxygen
permeability is needed. Similar to the compositions used for the
formation of phosphor patterns. As mentioned above, a
photosensitive composition having satisfactorily high resolution
and sensitivity is obtained by simply dispersing a predetermined
inorganic pigment. However, a variety of additives may be used in
order to regulate oxygen permeability and to improve physical
properties of coating films. For example, a saponified product of
polyvinyl acetate and an acrylic emulsion may be used.
[0060] No particular limitation is imposed on the inorganic pigment
used in this case, and there may be used any inorganic pigment
which is used in a color filter. The preferred content of
incorporation of the inorganic pigment is p-NVA (+another
polymer):crosslinking agent:phosphor=100:3-30:200-2000.
DETAILED DESCRIPTION OF THE INVENTION
[0061] The present invention will next be described in detail by
way of examples, which should not be construed as limiting the
invention.
[0062] [Manufacture Example of p-NVA]
[0063] NVA (75.76 g) and pure water (419.13 g) were placed into a
1-liter reactor equipped with a stirrer, a cooling apparatus, a
thermometer, and an inlet for nitrogen gas. Nitrogen gas was passed
for two hours while the temperature was maintained at 54.degree.
C., in order to purge the oxygen remaining in the apparatus, and
there were added an aqueous monomer solution and an aqueous
solution of VA-044 (0.15 g/4.96 g pure water) azo type
polymerization initiator, (product of Wako Pure Chemical Industries
Ltd.). Subsequently, polymerization was performed at the same
temperature for five hours while the reaction solution was
stirred.
[0064] The residual monomer content in the thus-obtained polymer
was 1.0% or less, as measured through GPC analysis.
[0065] The obtained polymer had a viscosity of 2700 cp (250C) at
the polymer concentration of 7.0 wt. % and had an average molecular
weight of 800000 (reduced as pullulan).
EXAMPLE 1
[0066] There was prepared a photosensitive composition having a
composition shown below.
[0067] The above-described polymer 7.0 wt. %: 171.4 g
[0068] Polyvinylpyrrolidone (K value 90) 20 wt. %: 15.0 g
[0069] (the above-described polymer:
polyvinylpyrrolidone=50:50)
[0070] Sodium 4,4'-diazidostilbene-2,2'-disulfonate
[0071] (hereinafter abbreviated DAS): 1.5 g
[0072] (the above-described polymer solid
content+polyvinylpyrrolidone solid content: DAS=100:10)
[0073] Pure water: 678.9 g
[0074] Silane coupling agent (KBM-603, Shin-Etsu Chemical Co.
Ltd.): 0.15 g
[0075] Emulgen-810 (Kao Corporation): 0.15 g
[0076] The photosensitive composition having the above formulation
was filtered by use of a 0.5-.mu.m-membrane filter, the remaining
matter was applied onto the inner surface of a face plate of a
color cathode-ray tube by spin-coating and then dried, to thereby
obtain a coating film having a thickness of 0.60 .mu.m.
[0077] Subsequently, a shadowmask having a pitch interval of 0.28
mm was attached to the coating film, and portions in the film
corresponding to green, blue, and red were respectively exposed for
15 seconds to the light of an ultra-high pressure mercury lamp
having an illuminance of 0.15 (mW/cm.sup.2) at 350 nm radiated on
the face plate from the distance of 30 cm. The relative humidity
during exposure was 45%.
[0078] Next, spray-development was performed with hot water
(Nozzle: made by Spraying System Co., No. 3, water pressure 2.0
kg/cm.sup.2, temperature: 40.degree. C., distance 15 cm).
[0079] Microscopic observation revealed that the obtained pattern
faithfully corresponded to the shadowmask.
[0080] Subsequently, a dispersion of graphite (Hitasol 66S: product
of Hitachi Powdered Metals Co., Ltd.) was applied onto the
above-described patterned face plate so that the graphite layer had
a thickness of 1.0 .mu.m, and the coated face plate was charged
with an aqueous solution containing 5%H.sub.2O.sub.2+0.1% sulfuric
acid and dipped for 60 seconds.
[0081] Next, hot water was sprayed for 30 seconds under the
following conditions: Nozzle; made by Spraying System Co., No. 10,
water pressure 5.0 kg/cm.sup.2, temperature: 40.degree. C., and
distance 15 cm. Pattern dots and graphite deposited thereon were
removed thereby together, to obtain a matrix pattern.
[0082] Microscopic observation revealed that the obtained matrix
holes faithfully corresponded to the pattern.
COMPARATIVE EXAMPLE 1
[0083] A photosensitive composition having the following
formulation was prepared.
1 Polyvinylpyrrolidone (K value 90) 20 wt.% 100 g DAS 2.0 g Pure
water 567 g Silane coupling agent (KBM-603) 0.2 g Emulgen-810 (Kao
Corporation) 0.2 g
[0084] The photosensitive composition having the above formulation
was filtered by use of a 0.5-.mu.m-membrane filter, the filtrate
was applied onto the inner surface of a face plate of a color
cathode-ray tube by spin-coating and dried, to thereby obtain a
coating film having a thickness of 0.75 .mu.m.
[0085] Subsequently, a shadowmask having a pitch interval of 0.28
mm was attached to the coating film and portions in the film
corresponding to green, blue, and red were respectively exposed for
25 seconds to the light of an ultra-high pressure mercury lamp
having an illuminance of 0.15 (mW/cm.sup.2) at 350 nm at the face
plate from the distance of 30 cm. The relative humidity during
exposure was 45%.
[0086] Next, spray-development was performed with hot water
(Nozzle: made by Spraying System Co., No. 3, water pressure 2.0
kg/cm.sup.2, temperature: 40.degree. C., distance 15 cm).
[0087] Subsequently, a dispersion of graphite (Hitasol 66S: product
of Hitachi Powdered Metals Co., Ltd.) was applied onto the
above-described patterned face plate so that the graphite layer had
a thickness of 1.0 .mu.m, and the coated face plate was charged
with an aqueous solution containing 5% H.sub.2O.sub.2+0.1% sulfuric
acid and dipped for 60 seconds.
[0088] Next, hot water was sprayed for 30 seconds under the
following conditions: Nozzle; made by Spraying System Co., No. 10,
water pressure 7.0 kg/cm.sup.2, temperature: 40.degree. C., and
distance 15 cm. Pattern dots and graphite deposited thereon were
removed thereby together, to obtain a matrix pattern.
[0089] When the resultant matrix holes were observed, they were
accompanied by fringes.
EXAMPLE 2
[0090] A glass substrate on which the above-described black matrix
was formed was precoated with a 0.1% PVA solution, which was then
dried. A phosphor slurry having the following composition was
applied and dried, to thereby obtain a coating film having a
thickness of 9-10 .mu.m. A phosphor pattern was then formed under
the below-described conditions. The obtained phosphor pattern
exhibited high density and high resolution, and no residual
phosphors were found on the black matrix.
[0091] (Composition of the Phosphor Slurry)
[0092] Green phosphor: 100 g
[0093] 15% Aqueous solution containing a polymer of Manufacture
Example: 64.3 g
[0094] 2% Aqueous solution of DAS: 25 g
[0095] 10% EG-40 (PVA, product of The Nippon Synthetic
[0096] Chemical Industry Co., Ltd.): 45 g
[0097] Pure water: 165.7 g
[0098] 5% Tamol 731 (surfactant, product of Rhom & Haas Co.): 1
g
[0099] 1% L-62 (BASF Co.): 2 g
[0100] (Conditions for Pattern Formation)
[0101] Shadowmask: pitch 0.28 mm
[0102] Light source-shadowmask distance: 30 cm
[0103] Light source: Ultra-high pressure mercury lamp
[0104] Illuminance at shadowmask face:
[0105] 0.20 mW/cm.sup.2
[0106] (UV=350 nm)
[0107] Exposure time: 70 seconds
[0108] Development: development by hot water spraying
[0109] (Nozzle: made by Spraying System Co., No. 3, water pressure
2.0 kg/cm.sup.2, temperature: 40.degree. C., distance 15 cm)
EXAMPLE 3
[0110] A photosensitive composition having the following
formulation was prepared.
[0111] The above-described polymer 7.0 wt. %: 100 g
[0112] Sodium 2.5-bis(4'-azido-2'
-sulfobenzylidene)cyclopentanonedisulfon- ate: 1.4 g
[0113] Red inorganic pigment
[0114] (Iron oxide-based, av. grain size 100 nm,
[0115] Ishihara Sangyo Kaisya, Ltd.): 28 g
[0116] Pure water: 350 g
[0117] Silane coupling agent (KBM-603): 0.14 g
[0118] 5% Tamol 731 (surfactant, product of Rhom & Haas Co.):
1.5 g
[0119] The photosensitive composition having the above formulation
was applied onto a soda glass plate (10 cm.times.10 cm) by
spin-coating and dried, to thereby obtain a coating film having a
thickness of 1.0 .mu.m. Subsequently, portions in the film
corresponding to red were exposed for 90 seconds to the light of an
ultra-high pressure mercury lamp having an illuminance of 0.20
(mW/cm.sup.2) at 350 nm at the glass plate. The distance between
the shadowmask having a pitch interval of 0.28 mm and the glass
plate was 1 cm, and that between the shadow mask and the lamp was
30 cm.
[0120] Next, spray-development was performed with hot water
(Nozzle: made by Spraying System Co., No. 3, water pressure 2.0
kg/cm.sup.2, temperature: 40.degree. C., distance 15 cm).
[0121] Microscopic observation revealed that the obtained pattern
of the red pigment layer faithfully corresponded to the
shadowmask.
* * * * *