U.S. patent application number 09/758433 was filed with the patent office on 2001-06-14 for coating composition and thin film layer for optical parts.
Invention is credited to Jiang, Jian, Ohta, Hiroshi.
Application Number | 20010003621 09/758433 |
Document ID | / |
Family ID | 15809606 |
Filed Date | 2001-06-14 |
United States Patent
Application |
20010003621 |
Kind Code |
A1 |
Jiang, Jian ; et
al. |
June 14, 2001 |
Coating composition and thin film layer for optical parts
Abstract
The present invention provides optical parts having good impact
resistance, good adhesiveness between the substrate and a thin film
layer coating formed thereon, good scratch resistance and good
antireflection capabilities. The thin film layer coating
composition comprises (1) a dithian ring containing sulfur compound
and/or a benzene ring containing sulfur compound, and (2) a
polyfunctional thiol compound.
Inventors: |
Jiang, Jian; (Tokyo, JP)
; Ohta, Hiroshi; (Tokyo, JP) |
Correspondence
Address: |
Raj S. Dave
Morrison & Foerster LLP
2000 Pennsylvania Ave., N. W.
Washington
DC
20006-1888
US
|
Family ID: |
15809606 |
Appl. No.: |
09/758433 |
Filed: |
January 12, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09758433 |
Jan 12, 2001 |
|
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09327072 |
Jun 7, 1999 |
|
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Current U.S.
Class: |
428/447 ;
427/508; 427/520; 428/451; 526/256; 526/286 |
Current CPC
Class: |
Y10T 428/31663 20150401;
Y10T 428/31667 20150401; C08G 75/045 20130101; C08G 75/0227
20130101; C09D 181/02 20130101; C08L 81/04 20130101; Y10T 428/265
20150115 |
Class at
Publication: |
428/447 ;
428/451; 427/508; 427/520; 526/256; 526/286 |
International
Class: |
B32B 009/04; C08F
012/30; C08F 128/02; C08F 028/02; C08F 228/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 12, 1998 |
JP |
165294/1998 |
Claims
What is claimed is:
1. A coating composition for optical parts, comprising: (i) a
dithian ring containing sulfur compound of a general formula (1):
5wherein n is an integer from 1 to 3, or a benzene ring containing
sulfur compound of a general formula (2): 6wherein m is 0 or 1, and
(ii) a polyfunctional thiol.
2. The coating composition of claim 1, wherein the polyfunctional
thiol is at least one thiol selected from the group consisting of
2,5-dimercaptomethyl-1,4-dithian and its oligomers,
1,2,3-trimercaptopropane,
tetrakis(7-mercapto-2,5-dithiaheptyl)methane, pentaerythritol
tetrakis(2-mercaptoacetate), 4,4'-thiodibenzenedithiol,
bis(4-mercapto-2-thiobutylphenyl) sulfide and
bis(7-mercapto-2,5-dithiahe- ptylphenyl) sulfide.
3. A thin film layer formed by curing the coating composition of
claim 1 or 2.
4. An optical part comprising the thin film layer of claim 3.
5. The optical part of claim 4, further comprising a hard coat
layer and an antireflection layer on the thin film layer.
6. The optical part of claim 5, wherein the hard coat layer
comprises particles of metal oxide and an organic silicon
compound.
7. The optical part of claim 4, 5 or 6, wherein the optical part is
an eyeglass lens.
8. A method for producing optical parts, comprising the steps of:
(A) applying a coating liquid onto a surface of a plastic
substrate, and (B) forming a thin film of said coating liquid,
wherein said coating liquid comprises (i) a dithian ring containing
sulfur compound of a general formula (1A): 7wherein n is an integer
from 1 to 3, or a benzene ring containing sulfur compound of a
general formula (2A): 8wherein m is 0 or 1, and (ii) a
polyfunctional thiol.
9. The method of claim 8, further comprising the steps of forming a
hard coat layer and an antireflection layer on the thin film layer.
Description
[0001] This application is based on Japanese application No.
H10-165294, filed on Jun. 12, 1998, the entire contents of which
are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a coating composition for optical
parts, a thin film layer made of the coating composition and an
optical part. In particular, it relates to a coating composition
favorable for obtaining optical parts having good impact
resistance, good adhesion between the substrate and the thin film
layer, good scratch resistance and good antireflection
capabilities, and also to a thin film layer made of the coating
composition and an optical part including the coating
composition.
BACKGROUND OF THE INVENTION
[0003] Recently, plastic materials have been used for optical parts
in place of inorganic glass, especially for eyeglass lenses,
because they are lightweight and have good dyeability and good
impact resistance. In particular, a diethylene glycol
bisallylcarbonate polymer (hereinafter referred to as CR-39) has
been used, primarily for plastic lenses. However, it has a
refractive index of 1.50, which is lower than that of inorganic
glass. Although lenses made of CR-39 have relatively strong power,
they are thick and do not generally have a good appearance. Various
types of high-refractive-index, low-chromatic-aberration plastic
lenses have also been tried, but they are also not free from
problems.
[0004] Ordinary plastic lenses are poor in scratch resistance. It
has been known to provide a silicone-based, hard coat layer on the
substrate surface of plastic lenses to improve scratch resistance.
In addition, the hard coat layer can be overcoated with an
inorganic antireflection layer. The reflection layer can be
applied, for example, by vacuum vapor deposition. The added
antireflection layer provides the additional benefit of reducing
surface reflection that could cause image flickering. In addition,
an outer layer can be provided to protect the inner layers from
aging. A problem that occurs, however, in forming both a hard coat
layer and an antireflection layer on the surface of a plastic
substrate is that the impact resistance of the lenses is low.
[0005] One means for improving the impact resistance of lenses
comprising a low-refractive-index substrate, such as CR-39, is to
form a thermosetting or thermoplastic resin layer between the
substrate and the hard coat layer (JP-A-63-87223, JP-A-63-141001).
However, lenses which have a high-refractive-index substrate, such
as polythiourethane, and a resin layer, will exhibit interfacial
light interference due to the difference in refractive index
between the substrate and the hard coat layer. The result will be
diminished optical quality, as well as inferior appearance. For
lenses of that type, a technique of forming a primer layer of a
thermosetting or thermoplastic resin that contains particles of
dispersed metal oxide has been used (JP-A-9-80206, JP-A-9-291227).
However, this method of incorporating particles of metal oxide in
the primer layer is problematic in that the impact resistance of
the lenses is lowered, even though the refractive index of the
layer can be increased.
SUMMARY OF THE INVENTION
[0006] In order to overcome many of the problems in the prior art,
the invention provides a high-refractive-index thin film layer,
which has good impact resistance, good adhesiveness between the
substrate and the thin film layer, good scratch resistance and good
antireflection capabilities.
[0007] The invention provides a coating composition for optical
parts, and in particular, a thin film layer on the substrate
surface. The thin film layer is preferably formed by curing the
coating composition. Also provided is a method for producing
optical parts, which comprises applying the coating liquid onto the
surface of a synthetic resin substrate to form thereon a thin film
layer.
[0008] In one aspect, the invention provides a coating composition
for optical parts, which comprises:
[0009] (i) a dithian ring containing sulfur compound of the general
formula (1): 1
[0010] wherein n is an integer from 1 to 3, or a benzene ring
containing sulfur compound of the general formula (2): 2
[0011] wherein m is 0 or 1, and
[0012] (ii) a polyfunctional thiol.
[0013] In a preferred embodiment, the polyfunctional thiol is at
least one thiol selected from the group consisting of
2,5-dimercaptomethyl-1,4-dith- ian and its oligomers,
1,2,3-trimercaptopropane, tetrakis(7-mercapto-2,5-d-
ithiaheptyl)methane, pentaerythritol tetrakis(2-mercaptoacetate),
4,4'-thiodibenzenedithiol, bis(4-mercapto-2-thiobutylphenyl)
sulfide and bis(7-mercapto-2,5-dithiaheptylphenyl) sulfide.
[0014] In another embodiment, the thin film layer can be applied to
an optical part, and the optical part can further comprise a hard
coat layer and an antireflection layer on the thin film layer. The
hard coat layer can comprise particles of metal oxide and an
organic silicon compound. The optical part can be an eyeglass
lens.
[0015] Yet another aspect of the invention provides a method for
producing optical parts, comprising the steps of:
[0016] (A) applying a coating liquid onto a surface of a plastic
substrate, and
[0017] (B) forming a thin film of said coating liquid, wherein said
coating liquid comprises
[0018] (i) a dithian ring containing sulfur compound of a general
formula (1A): 3
[0019] wherein n is an integer from 1 to 3, or a benzene ring
containing sulfur compound of the general formula (2A): 4
[0020] wherein m is 0 or 1, and
[0021] (ii) a polyfunctional thiol.
[0022] The method can further comprise the steps of forming a hard
coat layer and an antireflection layer on the thin film layer.
DETAILED DESCRIPTION OF THE INVENTION
[0023] We have found that when a thin film layer of a coating
composition for optical parts comprises (1) a dithian ring
containing sulfur compound and/or a benzene ring containing sulfur
compound, and (2) a polyfunctional thiol compound formed on the
surface of a plastic substrate, the resulting optical parts have
good impact resistance and good adhesion between the substrate and
the overlying layer. These good qualities remain even when a hard
coat film and an antireflection film are further formed on the thin
film layer.
[0024] The coating composition for optical parts comprises (1) a
dithian ring containing sulfur compound and/or a benzene ring
containing sulfur compound, and (2) a polyfunctional thiol
compound. Preferred examples of the dithian ring containing sulfur
compounds of formula (1) include 2,5-bis(2-thia-3-butenyl)-
1,4-dithian (n=1 in formula (1)),
2,5-bis(3-thia-4-pentenyl)-1,4-dithian (n=2 in the same),
2,5-bis(4-thia-5-hexenyl)-1,4-dithian (n=3 in the same), etc.
[0025] Preferred examples of the benzene ring containing sulfur
compounds of formula (2) include bis(4-vinylthiophenyl) sulfide
(m=0 in formula (2)), bis(4-vinylthiomethylphenyl) sulfide (m=1 in
the same), etc.
[0026] Preferred polyfunctional thiol compounds that can be used in
the invention are 2,5-dimercaptomethyl-1,4-dithian (hereinafter
referred to as DMMD), DMMD oligomers, 1,2,3-trimercaptopropane,
tetrakis(7-mercapto-2,5-dithiaheptyl)methane, pentaerythritol
tetrakis(2-mercaptoacetate), 4,4'-thiodibenzenedithiol,
bis(4-mercapto-2-thiobutylphenyl) sulfide,
bis(7-mercapto-2,5-dithiahepty- lphenyl) sulfide, etc. These
compounds can be used either singly or in combination.
[0027] In addition to those mentioned above, other polyfunctional
thiols can be used. Included are aliphatic polythiols such as
methanedithiol, 1,2-ethanedithiol, 1,1-propanedithiol,
1,2-propanedithiol, 1,3-propanedithiol, 2,2-propanedithiol,
1,6-hexanedithiol, 1,2,3-propanetrithiol, 1,1-cyclohexanedithiol,
1,2-cyclohexanedithiol, 2,2-dimethylpropane-1,3-dithiol,
3,4-dimethoxybutane-1,2-dithiol, 2-methylcyclohexane-2,3-dithiol,
1,1-bis(mercaptomethyl)cyclohexane, 2,3-dimercapto- 1-propanol
(2-mercaptoacetate), 2,3-dimercapto-1-propanol
(3-mercaptopropionate), diethylene glycol bis(2-mercaptoacetate),
diethylene glycol bis(3-mercaptopropionate), 1,2-dimercaptopropyl
methyl ether, 2,3-dimercaptopropyl methyl ether,
2,2-bis(mercaptomethyl)-1,3-pro- panedithiol, bis(2-mercaptoethyl)
ether, ethylene glycol bis(2-mercaptoacetate), ethylene glycol
bis(3-mercaptopropionate), trimethylolpropane
tris(2-mercaptoacetate), trimethylolpropane
tris(3-mercaptopropionate), pentaerythritol
tetrakis(2-mercaptoacetate), pentaerythritol
tetrakis(3-mercaptopropionate), etc.; and their halogen-substituted
compounds such as chlorine-substituted compounds,
bromine-substituted compounds, etc.; aromatic polythiols such as
1,2-dimercaptobenzene, 1,3-dimercaptobenzene,
1,4-dimercaptobenzene, 1,2-bis(mercaptomethyl)benzene,
1,3-bis(mercaptomethyl)benzene, 1,4-bis(mercaptomethyl)benzene,
1,2-bis(mercaptoethyl)benzene, 1,3-bis(mercaptoethyl)benzene,
1,4-bis(mercaptoethyl)benzene,
1,2-bis(mercaptomethyleneoxy)benzene,
1,3-bis(mercaptomethyleneoxy)benzen- e,
1,4-bis(mercaptomethyleneoxy)benzene,
1,2-bis(mercaptoethyleneoxy)benze- ne,
1,3-bis(mercaptoethyleneoxy)benzene,
1,4-bis(mercaptoethyleneoxy)benze- ne, 1,2,3-trimercaptobenzene,
1,2,4-trimercaptobenzene, 1,3,5-trimercaptobenzene,
1,2,3-tris(mercaptomethyl)benzene,
1,2,4-tris(mercaptomethyl)benzene,
1,3,5-tris(mercaptomethyl)benzene,
1,2,3-tris(mercaptoethyl)benzene, 1,2,4-tris(mercaptoethyl)benzene,
1,3,5-tris(mercaptoethyl)benzene,
1,2,3-tris(mercaptomethyleneoxy)benzene- ,
1,2,4-tris(mercaptomethyleneoxy)benzene,
1,3,5-tris(mercaptomethyleneoxy- )benzene,
1,2,3-tris(mercaptoethyleneoxy)benzene, 1,2,4-tris(mercaptoethyl-
eneoxy)benzene, 1,3,5-tris(mercaptoethyleneoxy)benzene,
1,2,3,4-tetramercaptobenzene, 1,2,3,5-tetramercaptobenzene,
1,2,4,5-tetramercaptobenzene,
1,2,3,4-tetrakis(mercaptomethyl)benzene,
1,2,3,5-tetrakis(mercaptomethyl)benzene,
1,2,4,5-tetrakis(mercaptomethyl)- benzene,
1,2,3,4-tetrakis(mercaptoethyl)benzene, 1,2,3,5-tetrakis(mercapto-
ethyl)benzene, 1,2,4,5-tetrakis(mercaptoethyl)benzene,
1,2,3,4-tetrakis(mercaptomethyleneoxy)benzene,
1,2,4,5-tetrakis(mercaptom- ethyleneoxy)benzene,
1,2,3,4-tetrakis(mercaptoethyleneoxy)benzene,
1,2,3,5-tetrakis(mercaptoethyleneoxy)benzene,
1,2,4,5-tetrakis(mercaptoet- hyleneoxy)benzene,
2,2'-dimercaptobiphenyl, 4,4'-dimercaptobiphenyl,
4,4'-dimercaptobibenzyl, 2,5-toluenedithiol, 3,4-toluenedithiol,
1,4-naphthalenedithiol, 1,5-naphthalenedithiol,
2,6-naphthalenedithiol, 2,7-naphthalenedithiol,
2,4-dimethylbenzene-1,3-dithiol, 4,5-dimethylbenzene-1,3-dithiol,
9,10-anthracenedimethanethiol,
1,3-di-(p-methoxyphenyl)propane-2,2-dithiol,
1,3-diphenylpropane-2,2-dith- iol, phenylmethane-1,1-dithiol,
2,4-di(p-mercaptophenyl)pentane, etc.; aromatic polythiols such as
1,2-bis(mercaptomethylthio)benzene,
1,3-bis(mercaptomethylthio)benzene,
1,4-bis(mercaptomethylthio)benzene,
1,2-bis(mercaptoethylthio)benzene,
1,3-bis(mercaptoethylthio)benzene,
1,4-bis(mercaptoethylthio)benzene,
1,2,3-tris(mercaptomethylthio)benzene,
1,2,4-tris(mercaptomethylthio)benzene,
1,3,5-tris(mercaptomethylthio)benz- ene,
1,2,3-tris(mercaptoethylthio)benzene,
1,2,4-tris(mercaptoethylthio)be- nzene,
1,3,5-tris(mercaptoethylthio)benzene,
1,2,3,4-tetrakis(mercaptometh- ylthio)benzene,
1,2,3,5-tetrakis(mercaptomethylthio)benzene,
1,2,4,5-tetrakis(mercaptomethylthio)benzene,
1,2,3,4-tetrakis(mercaptoeth- ylthio)benzene,
1,2,3,5-tetrakis(mercaptoethylthio)benzene,
1,2,4,5-tetrakis(mercaptoethylthio)benzene, etc.; aliphatic
polythiols such as bis(mercaptomethyl) sulfide, bis(mercaptoethyl)
sulfide, bis(mercaptopropyl) sulfide,
bis(mercaptoethylthio)methane, bis(2-mercaptoethylthio)methane,
bis(3-mercaptopropylthio)methane,
1,2-bis(mercaptomethylthio)ethane,
1,2-bis(mercaptoethylthio)ethane,
1,2-bis(mercaptopropylthio)ethane,
1,3-bis(mercaptomethylthio)propane,
1,3-bis(2-mercaptoethylthio)propane,
1,3-bis(3-mercaptopropylthio)propane- ,
1,2,3-tris(mercaptomethylthio)propane,
1,2,3-tris(2-mercaptoethylthio)pr- opane, 1
,2,3-tris(3-mercaptoethylthio)propane, 2,5-dimercapto-1,4-dithian-
, 2,5-dimercaptomethyl-1,4-dithian,
2,6-dimercaptomethyl-1,4-dithian, bis(mercaptomethyl) disulfide,
bis(mercaptoethyl) disulfide, bis(mercaptopropyl) disulfide, and
their thioglycolates and mercaptopropionates, as well as
hydroxymethyl sulfide bis(2-mercaptoacetate), hydroxymethyl sulfide
bis(3-mercaptopropionate), hydroxyethyl sulfide
bis(2-mercaptoacetate), hydroxyethyl sulfide
bis(3-mercaptopropionate), hydroxypropyl sulfide
bis(2-mercaptoacetate), hydroxypropyl sulfide
bis(3-mercaptopropionate), hydroxymethyl disulfide
bis(2-mercaptoacetate), hydroxymethyl disulfide
bis(3-mercaptopropionate)- , hydroxyethyl disulfide
bis(2-mercaptoacetate), hydroxyethyl disulfide
bis(3-mercaptopropionate), hydroxypropyl disulfide
bis(2-mercaptoacetate), hydroxypropyl disulfide
bis(3-mercaptopropionate)- , 2-mercaptoethyl ether
bis(2-mercaptoacetate), 2-mercaptoethyl ether
bis(3-mercaptopropionate), 1,4-dithian-2,5-dithiol
bis(2-mercaptoacetate), 1,4-dithian-2,5-dithiol
bis(3-mercaptopropionate)- , bis(2-mercaptoethyl) thioglycolate,
bis(2-mercaptoethyl) thiodipropionate, bis(2-mercaptoethyl)
4,4-thiodibutyrate, bis(2-mercaptoethyl) dithiodiglycolate,
bis(2-mercaptoethyl) dithiodipropionate, bis(2-mercaptoethyl)
4,4-dithiodibutyrate, bis(2,3-dimercaptopropyl) thiodiglycolate,
bis(2,3-dimercaptopropyl) thiodipropionate,
bis(2,3-dimercaptopropyl) dithiodiglycolate,
bis(2,3-dimercaptopropyl) dithiodipropionate, etc.
[0028] The ratio of the sulfur compound of formula (1) and/or the
sulfur compound of formula (2) to the polyfunctional thiol to be in
the composition is preferably from 4/1 to 1/1, more preferably from
3/2 to 1/1, in terms of the molar ratio of the functional groups,
i.e., sulfur compound/polyfunctional thiol.
[0029] The coating composition of the invention may contain any
components that may be used in ordinary coating compositions.
[0030] The thin film layer of the invention is preferably formed by
curing the coating composition, and the cured layer is generally
transparent. Heat, ultraviolet (UV) radiation or any curing agent
may be used for curing the coating composition to form the thin
film layer. The coating composition can be cured by heating in the
presence of a thermal polymerization catalyst, which includes, for
example, known azo compounds such as
2,2'-azobis-(2,4-dimethylvaleronitrile), 1,1
'-azobis(cyclohexane-1,1 -carbonitrile),
2,2'-azobis(4-methoxy-2,4-dimeth- yl-valeronitrile),
2,2'-azobisisobutyronitrile, 2-phenylazo-2,4-dimethyl-4-
-methoxyvaleronitrile, 2-cyano-2-propylazoformamide,
2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis(methyl
isobutyrate), etc.; organic peroxides such as benzoyl peroxide,
isobutyl peroxide, acetyl peroxide, etc. Curing it under UV
radiation may be effected in the presence of a photo-polymerization
catalyst, which includes, for example, known photo-catalysts such
as benzophenone, p-chlorobenzophenone, o-methoxybenzophenone,
acetophenone, o-methoxyacetophenone, 2,2-diethoxyacetophenone,
benzaldehyde, dibenzosuberone, thioxanthone, benzanthrone, benzoin
methyl ether, etc.
[0031] The amount of the catalyst to be used is not critical, but,
depending on the components constituting the coating composition in
general, it preferably falls between 0.01 and 5.0% by weight, more
preferably between 0.1 and 2.0% by weight of the coating
composition.
[0032] When the transparent thin film layer is formed by curing
under heat, it is desirable that the coating composition for
optical parts be applied to a lens, and then dried in hot air at a
temperature between 70 and 150.degree. C., preferably between 90
and 120.degree. C. If the temperature is lower than 70.degree. C.,
the transparent thin film layer will be insufficiently cured. On
the other hand, if the temperature is higher than 150.degree. C.,
the substrate and the transparent thin film layer will become
yellowed. The curing time can be generally between 15 and 120
minutes, preferably between 30 and 60 minutes. When the layer is
formed by curing with UV rays, it is desirable that the UV
radiation is applied for 1 to 120 seconds, preferably for 15 to 60
seconds. If UV radiation time is shorter than one second, the
transparent thin film layer will be insufficiently cured; but if
cured longer than 120 seconds, plastic lenses will become
yellowed.
[0033] The coating composition may be diluted with a solvent. Any
known solvent can be used, but preferred compounds are methyl ethyl
ketone, ethyl acetate, xylene, toluene, benzene, chloroform,
chlorobenzene, and o-dichlorobenzene. These may be used either
singly or in combination as a mixed solvent. A leveling agent may
be added to the coating composition for the propose of improving
coatability of the composition.
[0034] To apply the coating composition onto a substrate surface,
any known method of dipping, spin-coating, spraying, etc. may be
employed. Preferred methods are dipping and spin-coating. Prior to
applying the coating composition onto a substrate, the substrate
may be chemically processed with acids, alkalis or various organic
solvents, or physically processed with plasma, UV rays, etc., or
may be washed with various detergents.
[0035] It is desirable that the thin film layer of the invention
have a refractive index of not less than 1.60, more preferably
falling between 1.60 and 1.75. If the refractive index is lower
than 1.60, the thin film layer formed on a high-refractive-index
substrate will produce an interference fringe that degrades the
appearance of the coated substrate. The refractive index is
preferably that of a film composition having a thickness of 0.5 mm
as measured with an Abbe's refractometer.
[0036] The thin film layer preferably has a thickness of from 0.1
to 20 .mu.m, more preferably from 0.5 to 10 .mu.m. If the thickness
is less than 0.1 .mu.m, the layer will not provide significant
impact resistance to the coated substrate. If the thickness is
greater than 20 .mu.m, a hard coat layer provided on the thin film
layer can be more easily become cracked.
[0037] The optical parts of the invention comprise the thin film
layer on a plastic substrate and, preferably, a hard coat layer and
an antireflection layer on the thin film layer. The hard coat layer
preferably comprises fine metal oxide grains and an organic silicon
compound of, for example, the general formula (3):
(R.sup.1)a(R.sup.2).sub.bSi(OR.sup.3).sub.4-(a+b) (3)
[0038] wherein R.sup.1 and R.sup.2 each independently represent an
alkyl group, an alkenyl group, an aryl group, an acyl group, a
halogen atom, a glycidoxy group, an epoxy group, an amino group, a
phenyl group, a mercapto group, a methacryloxy group or a cyano
group; R.sup.3 represents an alkyl group having from 1 to 8 carbon
atoms, an alkoxy group, an acyl group or a phenyl group; and a and
b each independently represent 0 or 1.
[0039] As fine grain metal oxide colloidal particles, metal oxides
can be used. For example, tungsten oxide (WO.sub.3), zinc oxide
(ZnO), silicon oxide (SiO.sub.2), aluminum oxide (Al.sub.2O.sub.3),
titanium oxide (TiO.sub.2), zirconium oxide (ZrO.sub.2), tin oxide
(SnO.sub.2), beryllium oxide (BeO), antimony oxide
(Sb.sub.2O.sub.5) or the like can be used. These may be used either
singly or in combination.
[0040] The organic silicon compound of formula (3) is preferably:
Methyl silicate, ethyl silicate, n-propyl silicate, iso-propyl
silicate, n-butyl silicate, sec-butyl silicate, tert-butyl
silicate, tetraacetoxysilane, methyltrimethoxysilane,
methyltriethoxysilane, methyltripropoxysilane,
methyltriacetoxysilane, methyltributoxysilane,
methyltripropoxysilane, methyltriamyloxysilane,
methyltriphenoxysilane, methyltribenzyloxysilane,
methyltriphenethyloxysilane, glycidoxymethyltrimethoxysilane,
glycidoxymethyltriethoxysilane,
.alpha.-glycidoxyethyltriethoxysilane,
.beta.-glycidoxyethyltrimethoxysilane,
.beta.-glycidoxyethyltriethoxysila- ne,
.alpha.-glycidoxypropyltrimethoxysilane,
.alpha.-glycidoxypropyltrieth- oxysilane,
.beta.-glycidoxypropyltrimethoxysilane, .beta.-glycidoxypropylt-
riethoxysilane, .gamma.-glycidoxypropyltrimethoxysilane,
.gamma.-glycidoxypropyltriethoxysilane,
.gamma.-glycidoxypropyltripropoxy- silane,
.gamma.-glycidoxypropyltributoxysilane, .gamma.-glycidoxypropyltri-
phenoxysilane, .alpha.-glycidoxybutyltrimethoxysilane,
.alpha.-glycidoxybutyltriethoxysialne,
.beta.-glycidoxybutyltrimethoxysil- ane,
.beta.-glycidoxybutyltriethoxysilane,
.gamma.-glycidoxybutyltrimethox- ysilane,
.gamma.-glycidoxybutyltriethoxysilane, .delta.-glycidoxybutyltrim-
ethoxysilane, .delta.-glycidoxybutyltriethoxysilane,
(3,4-epoxycyclohexyl)methyltrimethoxysilane,
(3,4-epoxycyclohexyl)methylt- riethoxysilane,
.beta.-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,
.beta.-(3,4-epoxycyclohexyl)ethyltriethoxysilane,
.beta.-(3,4-epoxycycloh- exyl)ethyltripropoxysilane,
.beta.-(3,4-epoxycyciohexyl)ethyltributoxysila- ne,
.beta.-(3,4-epoxycyclohexyl)ethyltriphenoxysilane,
.gamma.-(3,4-epoxycyclohexyl)propyltrimethoxysilane,
.gamma.-(3,4-epoxycyclohexyl)propyltriethoxysilane,
.delta.-(3,4-epoxycyclohexyl)butyltrimethoxysilane,
.delta.-(.delta.3,4-epoxycyclohexyl)butyltriethoxysilane,
glycidoxymethylmethyldimethoxysilane,
glycidoxymethylmethyldiethoxysilane- ,
.alpha.-glycidoxyethylmethyldimethoxysilane,
.alpha.-glycidoxyethylmethy- ldiethoxysilane,
.beta.-glycidoxyethylmethyldimethoxysilane,
.beta.-glycidoxyethylmethyldiethoxysilane,
.alpha.-glycidoxypropylmethyld- imethoxysilane,
.alpha.-glycidoxypropylmethyldiethoxysilane,
.beta.-glycidoxypropylmethyldimethoxysilane,
.beta.-glycidoxypropylmethyl- diethoxysilane,
.gamma.-glycidoxypropylmethyldimethoxysilane,
.gamma.-glycidoxypropylmethyldiethoxysilane,
.gamma.-glycidoxypropylmethy- ldipropoxysilane,
.gamma.-glycidoxypropylmethyldibutoxysilane,
.gamma.-glycidoxypropylmethyldiphenoxysilane,
.gamma.-glycidoxypropylethy- ldimethoxysilane,
.gamma.-glycidoxypropylethyldiethoxysilane,
.gamma.-glycidoxypropylvinyldimethoxysilane,
.gamma.-glycidoxypropylvinyl- diethoxysilane,
.gamma.-glycidoxypropylphenyldimethoxysilane,
.gamma.-glycidoxypropylphenyldiethoxysilane, ethyltrimethoxysilane,
ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane,
vinyltrimethoxyethoxysilane, phenyltrimethoxysilane,
phenyltriethoxysilane, phenyltriacetoxysilane,
.gamma.-chloropropyltrimet- hoxysilane,
.gamma.-chloropropyltriethoxysilane, .gamma.chloropropyltriace-
toxysilane, 3,3,3-trifluoropropyltrimethoxysilane,
.gamma.-methacryloxypro- pyltrimethoxysilane,
.gamma.-mercaptopropyltrimethoxysilane,
.gamma.-mercaptopropyltriethoxysilane,
.beta.-cyanoethyltriethoxysilane, chloromethyltrimethoxysilane,
chloromethyltriethoxysilane,
N-(.beta.-aminoethyl)-.gamma.-aminopropyltrimethoxysilane,
N-(.beta.-aminoethyl)-.gamma.-aminopropylmethyldimethoxysilane,
.gamma.-aminopropylmethyldimethoxysilane,
N-(.beta.-aminoethyl)-.gamma. -aminopropyltriethoxysilane,
N-(.beta.-aminoethyl)-.gamma.-aminopropylmet- hyldiethoxysilane,
dimethyldimethoxysilane, phenylmethyldimethoxysilane,
dimethyldiethoxysilane, phenylmethyldiethoxysilane,
.gamma.-chloropropylmethyldimethoxysilane,
.gamma.-chloropropylmethyldiet- hoxysilane,
dimethyldiacetoxysilane, .gamma.-methacryloxypropylmethyldimet-
hoxysilane, .gamma.-methacryloxypropylmethyldiethoxysilane,
.gamma.-mercaptopropylmethyldimethoxysilane,
.gamma.-mercaptopropylmethyl- diethoxysilane,
methylvinyldimethoxysilane, methylvinyldiethoxysilane, etc.
[0041] The antireflection layer which can be formed over the hard
coat layer is not critical, and any known inorganic oxides may be
used. The layer may be of a single-layered or multi-layered film.
[Please list some antireflective materials used in this
invention.]
[0042] The substrate for the optical parts of the invention may be
any plastic substrate. For example, copolymers of methyl
methacrylate and one or more other monomers, copolymers of
diethylene glycol bisallyl carbonate and one or more other
monomers, polycarbonates, polystyrenes polyvinyl chlorides,
unsaturated polyesters, polyethylene terephthalates, polyurethanes
polythiourethanes, sulfide resins formed through ene-thiol
reaction, sulfur-containing vinyl polymers, etc. However, the
plastic substrates are not limited to those listed above.
[0043] The optical parts of the invention have many applications in
various fields, and are especially useful as eyeglass lenses.
[0044] The invention is further described by the Examples. However,
these Examples are not intended to restrict the scope of the
invention.
EXAMPLES
[0045] The physical properties of the products produced in the
Comparative Examples were measured according to the methods
mentioned below.
[0046] (1) Scratch Resistance Test:
[0047] The plastic lenses produced in the Examples and Comparative
Examples are rubbed with steel wool #0000, and visually checked for
scratch resistance. The criteria are as follows:
[0048] A: Slightly scratched, when rubbed strongly.
[0049] B: More noticably scratched, when rubbed strongly.
[0050] C: Scratched to the same degree as the non-coated plastic
substrate.
[0051] (2) Measurement of Refractive Index of Thin Film Layer:
[0052] A film sample having a thickness of 0.5 mm is prepared.
Refractive index is measured at 20.degree. C. with a precision
Abbe's refractometer manufactured by Atago Co.
[0053] (3) Adhesion Test:
[0054] The surface of each plastic lens is cross-cut at intervals
of 1 mm to form 100 cross-cuts thereon. An adhesive tape
(Cellotape, trade name, from Nichiban Co.) is adhered on the
cross-cut surface under strong pressure, and is then rapidly peeled
off. The surface is checked as to whether or not the cross-cuts are
peeled off along with the tape. Samples with no cross-cuts peeled
are represented by 100/100; and those with all cross-cuts peeled
are by 0/100. [It may be difficult for someone in the U.S. to do
the "adhesion test" if he cannot obtain the "Cellotape, trade name,
from Nichiban Co." Therefore, please provide some technical
specification on this "Cellotape."]
[0055] (4) Presence or Absence of Interference Fringe:
[0056] Each plastic lens is exposed to white light from a daylight
fluorescent lamp, and visually checked for appearance. The criteria
are as follows:
[0057] A: Interference fringes somewhat noticeable.
[0058] B: Interference fringes noticeable.
[0059] C: Interference fringes highly noticeable.
[0060] (5) Impact Resistance Test:
[0061] Each lens is subjected to a ball dropping test. A ball, made
of_having a diameter of_and weighing 25 g is spontaneously dropped
onto the center of each lens at a height of 127 cm. Lenses not
broken in the test are judged good, and those broken or slightly
cracked are judged not good.
[0062] .largecircle.: Good.
[0063] X: Not good.
[0064] (6) Outward Appearance:
[0065] Each lens is visually checked for its outward appearance
under a fluorescent lamp in a dark room.
Example 1
[0066] Preparation of Coating Liquid for Transparent Thin Film
Layer:
[0067] 252 parts by weight of
tetrakis(7-mercapto-2,5-dithiaheptyl)methane (thiol component) was
put into a glass reactor equipped with a magnetic stirrer. While
stirring, 196 parts by weight of 2,5-bis(2-thia-3-butenyl)-
-1,4-dithian was added dropwise thereto. One part by weight of a
photo-initiator, 2,2-diethoxyacetophenone, and, as solvents, 890
parts by weight of toluene and 890 parts by weight of methyl ethyl
ketone were added thereto. The mix was stirred well, until the
resulting solution became uniform. The solution was then filtered
to obtain a coating liquid for a transparent thin film layer.
[0068] Preparation of Hard Coat Liquid:
[0069] 246 parts by weight of fine inorganic grains of composite
sol consisting essentially of titanium oxide and zirconium oxide
(dispersed in methanol to have a solid content of 30%) was put into
a glass reactor equipped with a magnetic stirrer, and 73.8 parts by
weight of an organic silicon compound,
.gamma.-glycidoxypropyltrimethoxysilane (from Shin-etsu Chemical
Industry) was added dropwise thereto while stirring. After the
addition, 20 parts by weight of 1 N HCl, 410 parts by weight of a
solvent, ethyl cellosolve, 0.1 parts by weight of a silicone
surfactant, and 3 parts by weight of a curing promoter, aluminum
acetylacetonate were added thereto, and fully stirred. The
resulting mixture was filtered to obtain a hard coat
composition.
[0070] Coating and Curing of Transparent Thin Film Layer:
[0071] A lens having a refractive index of 1.71 (TESLALID, trade
name, from Hoya Corp., having a thickness of 1.1 mm at the center)
was dipped in an aqueous solution of 10% NaOH at 45.degree. C. for
5 minutes. After the lens was dried, it was coated with the coating
liquid by dipping at a pulling rate of 10 cm/min. Then the lens was
exposed to UV rays for 30 seconds thereby forming thereon a
transparent thin film layer.
[0072] Coating and Curing of Hard Coat Layer:
[0073] The lens coated with the transparent thin film layer was
washed with isopropyl alcohol (IPA) for 5 minutes. After the lens
was dried, it was coated with the hard coat liquid, prepared
previously, by a dipping at a pulling rate of 20 cm/min. Then the
lens was cured under heat at 110.degree. C. for 60 minutes.
[0074] Formation of Antireflection Layer:
[0075] The coated plastic lens was further coated with an
antireflection layer in the manner mentioned below. The coated
plastic lens was set in a vapor deposition chamber, and heated
therein at 85.degree. C. while the chamber was degassed. After the
vacuum conditions in the chamber reached 2.times.10.sup.-5 Torr, an
antireflection layer having a laminate structure
(.lambda./4-.lambda./2-.lambda./4) of SiO.sub.2 and ZrO.sub.2 was
vapor deposited onto the lens by heating with an electron beam. The
physical properties of the coated plastic lens are shown in Table
1.
Example 2
[0076] The same process as in Example 1 was repeated, except that
the thiol component in the coating liquid for the transparent thin
film layer comprised 122 parts by weight of
tetrakis(7-mercapto-2,5-dithiaheptyl)met- hane and 111 parts by
weight of 4,4'-thiodibenzenedithiol and that the amount of
2,5-bis(2-thia-3-butenyl)-1,4-dithian therein was 215 parts by
weight. The physical properties of the coated plastic lens are
shown in Table 1.
Example 3
[0077] The same process as in Example 1 was repeated, except that
the thiol component in the coating liquid for the transparent thin
film layer comprised 92 parts by weight of
tetrakis(7-mercapto-2,5-dithiaheptyl)meth- ane and 74 parts by
weight of 1,2,3-trimercaptopropane and that the amount of
2,5-bis(2-thia-3-butenyl)-1,4-dithian therein was 281 parts by
weight. The physical properties of the coated plastic lens are
shown in Table 1.
Example 4
[0078] The same process as in Example 1 was repeated, except that
118 parts by weight of 1,2,3-trimercaptopropane was used as the
thiol component in the coating liquid for the transparent thin film
layer and that the amount of 2,5-bis(2-thia-3-butenyl)-1,4-dithian
therein was 330 parts by weight. The physical properties of the
coated plastic lens are shown in Table 1.
Example 5
[0079] The same process as in Example 1 was repeated, except that
the thiol component in the coating liquid for the transparent thin
film layer comprised 114 parts by weight of
tetrakis(7-mercapto-2,5-dithiaheptyl)met- hane and 154 parts by
weight of an oligomer of 2,5-dimercaptomethyl-1,4-di- thian (DMMD)
and that the amount of 2,5-bis(2-thia-3-butenyl)-1,4-dithian
therein was 180 parts by weight. The physical properties of the
coated plastic lens are shown in Table 1.
Example 6
[0080] Preparation of Coating Liquid for Transparent Thin Film
Layer:
[0081] 252 parts by weight of
tetrakis(7-mercapto-2,5-dithiaheptyl)methane was put into a glass
reactor equipped with a magnetic stirrer. While stirring, 196 parts
by weight of 2,5-bis(2-thia-3-butenyl)-1,4-dithian was added
dropwise thereto. One part by weight of a thermal polymerization
initiator, 2,2-azobis-(2,4-dimethylvaleronitrile), and, as
solvents, 890 parts by weight of toluene and 890 parts by weight of
methyl ethyl ketone were added thereto, and stirred well until the
resulting solution became uniform. The solution was filtered to
obtain a coating liquid for a transparent thin film layer.
[0082] Coating and Curing of Transparent Thin Film Layer:
[0083] A lens having a refractive index of 1.71 (TESLALID, trade
name, from Hoya Corp., having a thickness of 1.1 mm at the center)
was dipped in an aqueous solution of 10% NaOH at 45.degree. C. for
5 minutes. After the lens was dried, it was coated with the coating
liquid, as prepared previously, by dipping at a pulling rate of 10
cm/min. Then the lens was cured by heating at 110.degree. C. for 30
minutes, thereby forming thereon a transparent thin film layer.
[0084] Except for the steps mentioned above, the lens was processed
in the same manner as in Example 1 to coat it with a hard coat
layer and an antireflection layer. The physical properties of the
coated plastic lens are shown in Table 1.
Example 7
[0085] Preparation of Coating Liquid for Transparent Thin Film
Layer:
[0086] 246 parts by weight of 2,5-bis(2-thia-3-butenyl)-1,4-dithian
was put into a glass reactor equipped with a magnetic stirrer.
While stirring, 202 parts by weight of pentaerythritol
tetrakis(2-mercaptoaceta- te) was added dropwise thereto. Two parts
by weight of a photo-initiator, 2,2-diethoxyacetophenone, and, as
solvents, 890 parts by weight of toluene and 890 parts by weight of
methyl ethyl ketone were added thereto, and stirred well until the
resulting solution became uniform. Then, this solution was filtered
to obtain a coating liquid for a transparent thin film layer.
[0087] In place of the lens having a refractive index of 1.71 used
in Example 1, a lens having a refractive index of 1.60 (EYAS, trade
name, from Hoya, having a thickness of 1.1 mm at the center) was
processed in the same manner as in Example 1, except that the
coating liquid prepared herein as above was used. The physical
properties of the coated plastic lens are shown in Table 1.
Example 8
[0088] Preparation of Coating Liquid for Transparent Thin Film
Layer:
[0089] 350 parts by weight of bis(4-vinylthiomethylphenyl) sulfide
was put into a glass reactor equipped with a magnetic stirrer.
While stirring, 99 parts by weight of 1,2,3-trimercaptopropane was
added dropwise thereto. Two parts by weight of a photo-initiator,
2,2-diethoxyacetophenone, and, as solvents, 890 parts by weight of
toluene and 890 parts by weight of methyl ethyl ketone were added
thereto, and stirred well until the resulting solution became
uniform. Then, this solution was filtered to obtain a coating
liquid for a transparent thin film layer.
[0090] The same lens as in Example 1 was processed in the same
manner as in Example 1, except that the coating liquid prepared
herein as above was used. The physical properties of the coated
plastic lens are shown in Table 1.
Example 9
[0091] Preparation of Coating Liquid for Transparent Thin Film
Layer:
[0092] 187 parts by weight of bis(4-vinylthiomethylphenyl) sulfide
and 151 parts by weight of 2,5-bis(2-thia-3-butenyl)- 1 ,4-dithian
were put into a glass reactor equipped with a magnetic stirrer.
While stirring, 107 parts by weight of 1,2,3-trimercaptopropane was
added dropwise thereto. Two parts by weight of a photoinitiator,
2,2-diethoxyacetophenone, and, as solvents, 890 parts by weight of
toluene and 890 parts by weight of methyl ethyl ketone were added
thereto, and stirred well until the resulting solution became
uniform. Then, this solution was filtered to obtain a coating
liquid for a transparent thin film layer.
[0093] The same lens as in Example 1 was processed in the same
manner as in Example 1, except that the coating liquid prepared
herein as above was used. The physical properties of the coated
plastic lens are shown in Table 1.
Comparative Example 1
[0094] The same process as in Example I was repeated, except that
the transparent thin film layer was not provided on the lens. The
physical properties of the coated plastic lens are shown in Table
1.
Comparative Example 2
[0095] The same process as in Example 6 was repeated, except that
the transparent thin film layer was not provided on the lens. The
physical properties of the coated plastic lens are shown in Table
1.
Comparative Example 3
[0096] The same process as in Example 7 was repeated, except that
the transparent thin film layer was not provided on the lens. The
physical properties of the coated plastic lens are shown in Table
1.
Comparative Example 4
[0097] A coating liquid for a transparent thin film layer was
prepared from 129 parts by weight of a commercially-available
polyester-polyol, "Desmophen 670" (from Sumitomo Bayer Urethane),
121 parts by weight of a commercially-available blocked
polyisocyanate, "BL-3175" (from Sumitomo Bayer Urethane), 2.2 parts
by weight of a curing promoter, dibutyltin dilaurate, and 1940
parts by weight of a solvent, methyl ethyl ketone. This was applied
onto the same lens as in Example 1, according to the same dipping
method as therein, and then cured by heating at 120.degree. C. for
30 minutes. Except for this step, the lens was processed in the
same manner as in Example 1. The physical properties of the coated
plastic lens are shown in Table 1.
1 TABLE 1 Refractive Presence Index of or Trans- Absence Out-
Scratch parent Ad- of Inter- Impact ward Resis- Thin Film hesive-
ference Resis- Appear- tance Layer ness Fringe tance tance Example
1 A 1.670 100/100 A .largecircle. good Example 2 A 1.705 100/100 A
.largecircle. good Example 3 A 1.681 100/100 A .largecircle. good
Example 4 A 1.686 100/100 A .largecircle. good Example 5 A 1.680
100/100 A .largecircle. good Example 6 A 1.670 100/100 A
.largecircle. good Example 7 A 1.637 100/100 A .largecircle. good
Example 8 A 1.702 100/100 A .largecircle. good Example 9 A 1.691
100/100 A .largecircle. good Com- A -- 100/100 A X good parative
Example 1 Com- A -- 100/100 A X good parative Example 2 Com- A --
100/100 A X good parative Example 3 Com- A 1.520 100/100 C
.largecircle. good parative Example 4
[0098] The present invention provides a thin film layer having a
specific composition and having a refractive index of not less than
1.60 on the surface of a substrate. The invention provides optical
parts having good impact resistance, good adhesiveness between the
substrate and the thin film layer, good scratch resistance and good
antireflection capabilities, even when a hard coat film and an
antireflection film are further provided on the thin film
layer.
[0099] The descriptions presented herein enable a person of
ordinary skill in the art to make and use the invention. Although
the present invention has been fully described by way of examples
with reference to the accompanying drawings, it is to be noted that
various modifications will be readily apparent to those skilled in
the art, and the generic principles defined herein may be applied
to other embodiments and applications without departing from the
spirit and scope of the invention. Thus, the present invention is
not intended to be limited to the embodiments shown, but is to be
accorded the widest scope consistent with the principles and
features disclosed herein.
* * * * *