Gel-glass dispersed liquid crystals

The present invention provides a gel-glass dispersed liquid crystal. The raw material composition of the gel-glass dispersed liquid crystal includes a three functionally substituted silane, two functionally substituted silane, a metal alkoxide and a liquid crystal. At least one of the non-hydrolyzable moieties of the three functionally substituted silane, two functionally substituted silane and metal alkoxide has at least one amino group or a reactive functional group. The refractive index of the oxide of the metal is not less than 1.52. The obtained gel-glass dispersed liquid crystal has good film integrity and flexibility and a low operation voltage.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a gel-glass dispersed liquid crystal and 
the raw material composition thereof, and more particularly relates to a 
raw material composition of a gel-glass dispersed liquid crystal, 
including a three functionally substituted silane, two functionally 
substituted silane and a metal alkoxide. At least one of the 
non-hydrolyzable moieties of the three functionally substituted silane, 
two functionally substituted silane and metal alkoxide has at least one 
amino group or a reactive functional group, and the refractive index of 
the oxide of the metal is not less than 1.52. 
2. Description of the Prior Art 
Liquid crystals can switch from a light scattering state to a transparent 
state upon application of an electric field. In the off-state (no applied 
field), the incident light is multiply scattered by the microdroplets of 
the liquid crystal, thus the liquid crystal is opaque. In the on-state 
(under an electric field), the directors of the liquid crystal are 
reoriented along the director of the field, thus the liquid crystal is 
transparent. Due to such properties, liquid crystal displays have been 
widely applied in watches, instruments, portable televisions, portable 
computers, projection screens of high definition televisions (HDTVs), 
liquid crystal light valves and light shutters. 
Recently, gel-glass dispersed liquid crystals (GDLCs) have become the focus 
of research. Sol-gel processes are used to trap liquid crystal droplets 
into gel-glass matrices. For example, Oton et al. (Liquid Crystal, 10(5), 
733(1991)) and Levy et al. (Material Letters, 10(9, 10), 470(1991)) 
disclose a sol-gel process for producing GDLCs, which involves subjecting 
a gel-glass matrix precursor and a liquid crystal to hydrolysis and 
condensation to form a sol-gel glass dispersed liquid crystal. The 
gel-glass matrix precursor used is a four functionally substituted silane 
or a mixture of a four functionally substituted silane and three 
functionally substituted silane. The substituted group is C.sub.2 H.sub.5 
O-- or CH.sub.3 COO--. 
The Oton et al. and Levy et al. GDLCs suffer from two problems. First, 
since the refractive index of the glass matrix and that of the liquid 
crystal differs greatly (the refractive index of the glass matrix is about 
1.43, while the refractive index of the liquid crystal is about 1.52), the 
GDLC obtained has low transmittance in the on-state, only 10-20%. Second, 
the applied voltage for switching the GDLC from the off-state to the 
on-state (called operation voltage) is too high, for example, with a 20 
.mu.m thickness GDLC, the operation voltage is 175 V. 
Haruvy and Webber (Chemical Material, 3, 501(1991)) report that the film 
integrity of GDLCs can be improved by introducing a three functionally 
substituted silane. Acid, ammonia water or methylamine which is a 
conventionally used catalyst serves to catalyze the sol-gel process. 
Although the resulting GDLC has good film integrity, its strength 
resistance is poor and the GDLC cracks easily upon being subjected to a 
hardness test. 
SUMMARY OF THE INVENTION 
Therefore, it is an object of the present invention to solve the 
above-mentioned problems and to provide a gel-glass dispersed liquid 
crystal, which has low off-state transmittance, high on-state 
transmittance, low operation voltage, good strength resistance, good film 
integrity and short gelation time. 
To achieve the above object, the gel-glass dispersed liquid crystal of the 
present invention is obtained from hydrolysis and condensation of a raw 
material composition of the gel-glass dispersed liquid crystal. The raw 
material composition of the gel-glass dispersed liquid crystal includes: 
(a) 0-30 wt % of a four functionally substituted silane selected from the 
group consisting of Si(OR.sup.1).sub.4 and Si(OOCR.sup.2).sub.4 ; 
(b) 0-60 wt % of a three functionally substituted silane selected from the 
group consisting of R.sup.3 Si(OR.sup.1).sub.3 and R.sup.3 
Si(OOCR.sup.2).sub.3 ; 
(c) 3-70 wt % of a two functionally substituted silane selected from the 
group consisting of R.sup.4 R.sup.5 Si(OR.sup.1).sub.2 and R.sup.4 R.sup.5 
Si(OOC.sup.2).sub.2 ; 
(d) 0-30 wt % of a metal alkoxide (R.sup.6).sub.m M(OR.sup.7).sub.n ; 
(e) 10-80 wt % of a liquid crystal; and 
(f) 0-30 wt % of additives; 
wherein 
each of R.sup.1, R.sup.2 and R.sup.7 is an aliphatic group having not more 
than 7 carbon atoms, 
each of R.sup.3, R.sup.4, R.sup.5 and R.sup.6 is selected from the group 
consisting of an aliphatic group, aromatic group, substituted aliphatic 
group, substituted aromatic group, polymer moiety and substituted polymer 
moiety, 
wherein 
each of the aliphatic group, aromatic group, substituted aliphatic group 
and substituted aromatic group has not more than 24 carbon atoms, 
each of the polymer moiety and substituted polymer moiety has a molecular 
weight of not more than 10,000, 
the substituted group contained in the substituted aliphatic group, 
substituted aromatic group and substituted polymer moiety is an amino 
group or a reactive functional group, and 
wherein 
M is a metal atom, wherein the refractive index of the oxide of the metal 
atom is not less than 1.52, 
m is an integer between 0 and 4, 
n is an integer between 2 and 6, 
the additives are capable of improving the function and characteristics of 
the gel-glass dispersed liquid. 
According to an aspect of the invention, the raw material composition of 
the gel-glass dispersed liquid crystal includes a two functionally 
substituted silane. 
According to the second aspect of the invention, the raw material 
composition of the gel-glass dispersed liquid crystal includes a metal 
alkoxide, in which the refractive index of the oxide of the metal is not 
less than 1.52. 
According to the third aspect of the invention, at least one of the 
non-hydrolyzable moieties of the three functionally substituted silane, 
two functionally substituted silane and metal alkoxide contained in the 
raw material composition of the gel-glass dispersed liquid crystal has at 
least one amino group or a reactive functional group. 
DETAILED DESCRIPTION OF THE INVENTION 
The gel-glass matrix for the gel-glass dispersed liquid crystal 
(hereinafter abbreviated as GDLC) of the present invention is prepared by 
the sol-gel method. The method involves subjecting, in the presence of 
water, the silicon alkoxide, i.e., Si(OR.sup.1).sub.4 and 
Si(OOCR.sup.2).sub.4 and the metal alkoxide (R.sup.6).sub.m 
M(OR.sup.7).sub.n to hydrolysis in order to obtain silicon alcohols and 
metal alcohols, which are in turn subjected to condensation to form a 
gel-glass matrix with a network structure. The reactions as mentioned 
above are outlined as follows: 
EQU Si(OR.sup.1).sub.4 +4H.sub.2 O.fwdarw.Si(OH).sub.4 +4 R.sup.1 OH 
EQU Si(OOCR.sup.2).sub.4 +4 H.sub.2 O.fwdarw.Si(OH).sub.4 +4 R.sup.2 COOH 
EQU (R.sup.6).sub.m M(OR.sup.7).sub.n +n H.sub.2 O.fwdarw.(R.sup.6).sub.m 
M(OH).sub.n +n R.sup.7 OH 
##STR1## 
wherein 
each of R.sup.1, R.sup.2 and R.sup.7 is an aliphatic group having not more 
than 7 carbon atoms; 
R.sup.6 is selected from the group consisting of an aliphatic group, 
aromatic group, substituted aliphatic group, substituted aromatic group, 
polymer moiety and substituted polymer moiety; 
wherein 
each of the aliphatic group, aromatic group, substituted aliphatic group 
and substituted aromatic group has not more than 24 carbon atoms, and 
each of the polymer moiety and substituted polymer moiety has a molecular 
weight of not more than 10,000; and 
wherein 
M is a metal atom, wherein the refractive index of the oxide of the metal 
atom is not less than 1.52; 
m is an integer between 0 and 4; 
n is an integer between 2 and 6; and 
each of x, y and z is an integer larger than 0. 
The raw material composition of the gel-glass dispersed liquid crystal 
includes a four functionally substituted silane, a three functionally 
substituted silane, a two functionally substituted silane, a metal 
alkoxide, a liquid crystal and additives. 
The four functionally substituted silane suitable for use in the present 
invention is represented by the formula of Si(OR.sup.1).sub.4 or 
Si(OOCR.sup.2).sub.4. The three functionally substituted silane suitable 
for use in the present invention is represented by R.sup.3 
Si(OR.sup.1).sub.3 or R.sup.3 Si(OOCR.sup.2).sub.3. The two functionally 
substituted silane suitable for use in the present invention is 
represented by R.sup.4 R.sup.5 Si(OR.sup.1).sub.2 or R.sup.4 R.sup.5 
Si(OOCR.sup.2).sub.2. 
As to the R group, each of R.sup.1 and R.sup.2 is an aliphatic group having 
not more than 7 carbon atoms, and each of R.sup.3, R.sup.4 and R.sup.5 is 
selected from the group consisting of an aliphatic group, aromatic group, 
substituted aliphatic group, substituted aromatic group, polymer moiety 
and substituted polymer moiety. Each of the aliphatic group, aromatic 
group, substituted aliphatic group and substituted aromatic group has not 
more than 24 carbon atoms, and each of the polymer moiety and substituted 
polymer moiety has a molecular weight of not more than 10,000. The 
substituted group contained in the substituted aliphatic group, 
substituted aromatic group and substituted polymer moiety is an amino 
group or a reactive functional group. 
Conventionally, to shorten the time for preparing GDLCs, an acidic or basic 
solution such as ammonia water, formamide or methylamine is frequently 
added to the raw material composition of a GDLC to catalyze the sol-gel 
process. However, in the present invention, the above catalysts have not 
been used. The reason why we do not use the conventionally used catalysts 
is because that although the above catalysts do shorten the preparation 
time, since they are volatile, during the GDLC preparation process, the 
catalyst will evaporate, thus the reaction rate is not easily controlled 
and the vapor is hazardous to the operators. Also, the resultant GDLC will 
have unacceptably large pores. 
Furthermore, according to the preceding description, we know that Haruvy 
and Webber (Chemical Material, 3, 501(1991)) use acid, ammonia water or 
methylamine to catalyze the reaction. Also, a three functionally 
substituted silane is introduced to improve the film integrity of GDLCs. 
Results show that although the resulting GDLC has good film integrity, the 
strength resistance is poor and the GDLC cracks easily upon being 
subjected to a hardness test. This proves that smaller molecules such as 
ammonia water, formamide and methylamine are not suitable catalysts for 
preparing GDLCs. 
Alternatively, in the present invention, a three functionally substituted 
silane, a two functionally substituted silane or a metal alkoxide, wherein 
at least one of the non-hydrolyzable moieties of which has at least one 
amino group or a reactive functional group, is added into the raw material 
composition of the GDLC to accelerate the hydrolysis and condensation 
during the sol-gel process. The resultant GDLC has good film integrity and 
flexibility and does not crack easily upon being subjected to a hardness 
test. 
The reactive functional group can undergo hydrolysis and condensation and 
is selected from the group consisting of 
##STR2## 
or the reactive functional group can form a linkage at room temperature, 
at an elevated temperature or upon exposure to light, 
wherein 
p is an integer between 1 and 3, 
X is selected from the group consisting of OOCR, OR, H, Cl, Br, I and F; 
and 
wherein R is an aliphatic group having not more than 7 carbon atoms. 
The most notable feature resulted from the introduction of amino group or 
reactive functional group resides in that the operation voltage of the 
resultant GDLC is greatly lowered and can be determined. For example, the 
operation voltage of the GDLC obtained by Oton et al. with a 20 .mu.m 
thickness, is 175 V. While in the present invention, the 12.5 .mu.m thick 
GDLC film obtained from the raw material of 3-aminopropyltrimethoxysilane 
and titanium ethoxide has an operation voltage of 58 V (see Example 11), 
and the 12.5 .mu.m thick GDLC film obtained from the raw material of 
N-3-trimethoxysilylpropyl!ethylene-diamine and titanium ethoxide has an 
operation voltage of 34 V (see Example 10). The presence of amino group on 
the non-hydrolyzable moiety of the silicon alkoxide is deemed to be the 
contributing factor to the low operation voltage required by the resultant 
GDLC. 
The four functionally substituted silane suitable for use in the present 
invention includes tetramethoxysilane, tetraethoxysilane and 
tetrapropoxysilane. 
The non-hydrolyzable moieties of the three functionally substituted silane 
suitable for use in the present invention may or may not contain an amino 
group and may or may not contain a reactive functional group defined as 
above. Examples of the three functionally substituted silane are 
methyltriethoxysilane, trimethoxypropylsilane, 
(3-chloropyl)trimethoxysilane, N-3-trimethoxysilylpropyl!-ethylenediamine 
and 3-aminopropyltrimethoxysilane. 
The non-hydrolyzable moieties of the two functionally substituted silane 
suitable for use in the present invention may or may not contain an amino 
group and may or may not contain a reactive functional group defined as 
above. A preferred example of the two functionally substituted silane is 
3-(diethoxymethylsilyl)propylamine. 
In order to obtain a better result, the total weight of the amino 
group-containing silanes of components (b) and (c) or the total weight of 
the reactive functional group-containing silanes of components (b) and (c) 
is preferably not lower than 5% of the total weight of components (a), (b) 
and (c). 
In the present invention, the addition of the two functionally substituted 
silane can further lower the operation voltage of the GDLC. For example, 
the GDLC obtained from the raw material containing 
3-(diethoxymethylsilyl)propylamine (which is a two functionally 
substituted silane) has an operation voltage only of 4 V (see Example 22). 
The low operation voltage results in lower electricity consumption to 
drive the GDLC. Furthermore, the introduction of the two functionally 
substituted silane will increase the amount of the linear part in the 
network structure of the GDLC, thus making the GDLC more flexible. 
Generally speaking, in the GDLC, the larger difference between the 
refractive index of the matrix and that of the liquid crystal leads to 
better on-state transmittance. A commonly used liquid crystal has a 
refractive index of above 1.49, however, the refractive index of a glass 
matrix obtained from silicon alkoxides only containing aliphatic groups 
can hardly reach 1.48. One way to enhance the refractive index of the 
glass matrix is to introduce aromatic groups onto the non-hydrolyzable 
moieties of the silicon alkoxides. Alternatively, the addition of a metal 
alkoxide to the raw materials of the gel-glass matrix is also effective. 
The metal alkoxide suitable for use in the present invention meets the 
requirement that the refractive index of the oxide of the metal atom be 
not less than 1.52. The addition of such a metal alkoxide can thus enhance 
the refractive index of the glass matrix to match that of the liquid 
crystal. 
The metal alkoxide can be represented by (R.sup.6).sub.m M(OR.sup.7).sub.n, 
wherein M is a metal atom, R.sup.6 is selected from the group consisting 
of an aliphatic group, aromatic group, substituted aliphatic group, 
substituted aromatic group, polymer moiety and substituted polymer moiety, 
R.sup.7 is an aliphatic group having not more than 7 carbon atoms, m is an 
integer between 0 and 4 and n is an integer between 2 and 6. Each of the 
aliphatic group, aromatic group, substituted aliphatic group and 
substituted aromatic group has not more than 24 carbon atoms, and each of 
the polymer moiety and substituted polymer moiety has a molecular weight 
of not more than 10,000. The substituted group contained in the 
substituted aliphatic group, substituted aromatic group and substituted 
polymer moiety is amino group or a reactive functional group defined as 
above. 
The metal atom (M) of the metal alkoxide (R.sup.6).sub.m M(OR.sup.7).sub.n 
can be lead, tantalum, barium, calcium, strontium, lanthanum, yttrium, 
indium, tin, iridium, aluminum, titanium, niobium, zirconium, zinc or 
germanium. The most preferred example is titanium, and the metal alkoxide 
is preferably titanium ethoxide. 
The raw materials of the GDLC of the present invention can further include 
one or more additives which are capable of improving the function and 
characteristics of the GDLC, for example, lowering the operation voltage 
and enhancing the on-state transmittance of the GDLC. The additives 
suitable for use include transparent polymers, transparent oligomers, 
transparent polymer precursors, substituted transparent polymers, 
substituted transparent oligomers, and substituted transparent polymer 
precursors. Upon the addition of such polymer-type additives, a composite 
glass-dispersed liquid crystal results. 
The substituted group contained in the substituted transparent polymers, 
substituted transparent oligomers, and substituted transparent polymer 
precursors is amino group or a reactive functional group, wherein the 
reactive functional group can undergo hydrolysis and condensation and is 
selected from the group consisting of 
##STR3## 
or the reactive functional group can form a linkage at room temperature, 
at an elevated temperature or upon exposure to light, 
wherein 
p is an integer between 1 and 3; 
X is selected from the group consisting of OOCR, OR, H, Cl, Br, I and F; 
and 
wherein R is an aliphatic group having not more than 7 carbon atoms. 
The liquid crystals suitable for use in the present invention include 
nematic liquid crystals, smectic liquid crystals, cholesteric liquid 
crystals and ferroelectric liquid crystals. The driving force to reorient 
the resultant GDLC can be an electric field or magnetic field or any other 
suitable field according to the liquid crystal used. 
The following specific examples are intended to demonstrate this invention 
more fully without acting as a limitation upon its scope, since numerous 
modifications and variations will be apparent to those skilled in the art.

EXAMPLES 
Table I below shows the abbreviations of alkoxides used in the following 
examples. 
TABLE I 
______________________________________ 
Abbreviations of alkoxides used in the present invention 
Abbrevia- 
No. silicon alkoxide 
Chemical formula tion 
______________________________________ 
1 Methyl- (C.sub.2 H.sub.5 O).sub.3 SiCH.sub.3 
MTEOS 
triethoxysilane 
2 Tetraethylortho- 
Si(OC.sub.2 H.sub.5).sub.4 
TEOS 
silicate (or Tetra- 
ethoxysilane) 
3 Trimethoxy- (CH.sub.3 O).sub.3 Si(CH.sub.2).sub.2 CH.sub.3 
TMOPS 
propylsilane 
4 N-3-Tri- (CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 NHCH.sub.2 CH.sub.2 
NH.sub.2 TMOSPED 
methoxysilyl- 
propyl!ethylene- 
diamine 
5 (3-Chloropyl)tri- 
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 Cl 
CLTMOS 
methoxysilane 
6 3-Aminopropyl- 
(CH.sub.3 O).sub.3 Si(CH.sub.2).sub.3 NH.sub.2 
APTMOS 
trimethoxysilane 
7 3-(Diethoxy- 
(C.sub.2 H.sub.5 O).sub.2 Si(CH.sub.3)(CH.sub.2).sub.3 
NH.sub.2 DEOMSP 
methylsilyl)- 
propylamine 
8 Titanium ethoxide 
Ti(OC.sub.2 H.sub.5).sub.4 
TIE 
______________________________________ 
T I: Preparation of gel-glass matrix 
Example 1 
1.000 g of TMOSPED and 0.220 g of TIE were homogeneously mixed. After 
vigorous stirring, the mixture was cast on a Teflon disk and placed in a 
humidity chamber for temperature and humidity control until the formation 
of gel-glass occurred. The hardness of the gel-glass was measured 
according to the ASTM-D2240 Shore D method. The refractive index of the 
gel-glass was measured using Abbe refractometer with a sodium light source 
(589 nm). The characteristics of the gel-glass matrix obtained are 
summarized in Table II. 
Example 2 
The same procedures as described in Example 1 were employed except that the 
raw materials of the gel-glass used were 1.000 g of APTMOS and 0.212 g of 
TIE. The characteristics of the gel-glass matrix obtained are summarized 
in Table II. 
Example 3 
The same procedures as described in Example 1 were employed except that the 
raw materials of the gel-glass used were 0.300 g of TEOS, 0.700 g of 
DEOMSP and 0.176 g of TIE. The characteristics of the gel-glass matrix 
obtained are summarized in Table II. 
Example 4 
The same procedures as described in Example 1 were employed except that the 
raw materials of the gel-glass used were 0.300 g of MTEOS, 0.700 g of 
DEOMSP and 0.176 g of TIE. The characteristics of the gel-glass matrix 
obtained are summarized in Table II. 
Example 5 
The same procedures as described in Example 1 were employed except that the 
raw materials of the gel-glass used were 0.300 g of TMOPS, 0.700 g of 
DEOMSP and 0.176 g of TIE. The characteristics of the gel-glass matrix 
obtained are summarized in Table II. 
Example 6 
The same procedures as described in Example 1 were employed except that the 
raw materials of the gel-glass used were 0.300 g of CLTMOS, 0.700 g of 
DEOMSP and 0.176 g of TIE. The characteristics of the gel-glass matrix 
obtained are summarized in Table II. 
Example 7 
The same procedures as described in Example 1 were employed except that the 
raw materials of the gel-glass used were 0.300 g of TMOSPED, 0.700 g of 
DEOMSP and 0.176 g of TIE. The characteristics of the gel-glass matrix 
obtained are summarized in Table II. 
Example 8 
The same procedures as described in Example 1 were employed except that the 
raw materials of the gel-glass used were 0.600 g of APTMOS, 0.400 g of 
DEOMSP and 0.136 g of TIE. The characteristics of the gel-glass matrix 
obtained are summarized in Table II. 
Example 9 
The same procedures as described in Example 1 were employed except that the 
raw materials of the gel-glass used were 0.600 g of APTMOS, 0.400 g of 
DEOMSP and 0.176 g of TIE. The characteristics of the gel-glass matrix 
obtained are summarized in Table II. 
Comparative Example 1 
1.000 g of TEOS was homogeneously mixed with 1,000 g of ethanol (99.5%) and 
stirred for several minutes. 0.136 g of TIE was dropwisely added to the 
silicon alkoxide solution in a dry glove box. After vigorous stirring, the 
mixture was cast on a Teflon disk and placed in a humidity chamber for 
temperature and humidity control until the formation of gel-glass 
occurred. The characteristics of the gel-glass matrix obtained are 
summarized in Table II. 
Comparative Example 2 
The same procedures as described in Comparative Example 1 were employed 
except that the raw materials of the gel-glass used were 1.000 g of MTEOS 
and 0.220 g of TIE. The characteristics of the gel-glass matrix obtained 
are summarized in Table II. 
Comparative Example 3 
The same procedures as described in Comparative Example 1 were employed 
except that the raw materials of the gel-glass used were 1.000 g of TMOPS 
and 0.220 g of TIE. The characteristics of the gel-glass matrix obtained 
are summarized in Table II. 
Comparative Example 4 
The same procedures as described in Comparative Example 1 were employed 
except that the raw materials of the gel-glass used were 1.000 g of CLTMOS 
and 0.220 g of TIE. The characteristics of the gel-glass matrix obtained 
are summarized in Table II. 
T II: Preparation of GDLC 
Example 10 
Liquid crystal E7 (purchased from Merck) was added to the gel-glass matrix 
solution of Example 1 and then stirred at 40.degree. C. E7 was in a 
quantity sufficient to provide a mixture containing 15 wt % of E7, based 
on the total weight of the gel-glass matrix and E7. The mixture was cast 
on a cleaned STN-grade ITO (indium tin oxide) glass (120 
.OMEGA.cm/.quadrature.) for 20 minutes. A second ITO glass was placed on 
the surface of the GDLC to form a sandwich device with a 12.5 .mu.m mylar 
spacer under ambient conditions, and then was left for one day. This 
device was then placed in an oven at 60.degree. C. for two days. 
The electrooptic characteristics of the GDLC obtained, including initial 
voltage, operation voltage and response time, were measured using a He-Ne 
laser (632.8 nm) incorporating an optical lens and detectors and an ac 
power source with a square waveform at a frequency of 1 kHz. The results 
are summarized in Table III. 
Example 11 
The same procedures described in Example 10 were employed except that E7 
was added to the gel-glass matrix solution of Example 2 and E7 was in a 
quantity sufficient to provide a mixture containing 15 wt % of E7, based 
on the total weight of the gel-glass matrix and E7. The results are 
summarized in Table III. 
Example 12 
The same procedures described in Example 10 were employed except that E7 
was added to the gel-glass matrix solution of Example 3 and E7 was in a 
quantity sufficient to provide a mixture containing 50 wt % of E7, based 
on the total weight of the gel-glass matrix and E7. The results are 
summarized in Table III. 
Examples 13-14 
The gel-glass matrix solution of Example 4 was divided into two portions, 
to each of which E7 was added and then stirred at 40.degree. C. 
respectively. For the two portions, E7 was in a quantity sufficient to 
provide a mixture containing 30 wt % and 50 wt % of E7 respectively, based 
on the total weight of the gel-glass matrix and E7. The rest of the 
procedures were the same as Example 10. The results are summarized in 
Table III. 
Example 14 
The same procedures described in Example 10 were employed except that E7 
was added to the gel-glass matrix solution of Example 4 and E7 was in a 
quantity sufficient to provide a mixture containing 50 wt % of E7, based 
on the total weight of the gel-glass matrix and E7. The results are 
summarized in Table III. 
Example 15 
The same procedures described in Example 10 were employed except that E7 
was added to the gel-glass matrix solution of Example 5 and E7 was in a 
quantity sufficient to provide a mixture containing 50 wt % of E7, based 
on the total weight of the gel-glass matrix and E7. The results are 
summarized in Table III. 
Example 16 
The same procedures described in Example 10 were employed except that E7 
was added to the gel-glass matrix solution of Example 6 and E7 was in a 
quantity sufficient to provide a mixture containing 50 wt % of E7, based 
on the total weight of the gel-glass matrix and E7. The results are 
summarized in Table III. 
Examples 17-19 
The gel-glass matrix solution of Example 7 was divided into three portions, 
to each of which was added with E7 and then stirred at 40.degree. C. 
respectively. For the three portions, E7 was in a quantity sufficient to 
provide a mixture containing 15 wt %, 30 wt % and 50 wt % of E7 
respectively, based on the total weight of the gel-glass matrix and E7. 
The rest of the procedures were the same as Example 10. The results are 
summarized in Table III. 
Examples 20-22 
The gel-glass matrix solution of Example 8 was divided into three portions, 
to each of which E7 was added and then stirred at 40.degree. C. 
respectively. For the three portions, E7 was in a quantity sufficient to 
provide a mixture containing 15 wt %, 30 wt % and 50 wt % of E7 
respectively, based on the total weight of the gel-glass matrix and E7. 
The rest of the procedures were the same as Example 10. The results are 
summarized in Table III. 
Example 23 
The same procedures described in Example 10 were employed except that E7 
was added to the gel-glass matrix solution of Example 9 and E7 was in a 
quantity sufficient to provide a mixture containing 50 wt % of E7, based 
on the total weight of the gel-glass matrix and E7. The results are 
summarized in Table III. 
Comparative Example 5-8 
Ethanol was removed from each of the gel-glass matrix solution of 
Comparative Examples 1-4 under vacuum. Afterwards, E7 was added to each of 
the resulting four gel-glass matrix solutions respectively and then 
stirred at 40.degree. C. For each of the four portions, E7 was in a 
quantity sufficient to provide a mixture containing 15 wt % of E7 
respectively, based on the total weight of the gel-glass matrix and E7. 
The rest of the procedures were the same as Example 10. The results are 
summarized in Table III. 
Referring now to Table II, comparing Examples 3, 4, 5 and 6 with 
Comparative Examples 1, 2, 3 and 4, respectively, it is obvious that with 
the addition of DEOMSP (a two functionally substituted silane), the 
resultant glass matrix has enhanced film integrity and flexibility and 
does not crack under ambient conditions. 
Further comparing Examples 3, 4, 5 and 6 with Examples 7, 8 and 9, it is 
found that with the introduction of TMOSPED or APTMOS, both of which is an 
amino-substituted silane, the resultant glass matrix is much more 
flexible. 
Referring now to Table III, comparing Examples 12, 13 plus 14, 15 and 16 
with Comparative Examples 5, 6, 7 and 8, respectively, it is found that 
with the addition of DEOMSP (a two functionally substituted silane), the 
operation voltage of the resultant GDLC is lowered to a value which can be 
determined. The lowest operation voltage is obtained when the raw 
materials of the GDLC used are APTMOS, DEOMSP and TIE, that is, 
3-aminopropyltrimethoxysilane, 3-(diethoxymethylsilyl)propylamine and 
titanium ethoxide (see Example 22). 
TABLE II 
__________________________________________________________________________ 
Characteristics of gel-glass matrices 
Weight ratio Hardness 
Refractive 
Example No. 
Composition in part 
Film integrity 
(Shore-D) 
index 
__________________________________________________________________________ 
Example 1 
TMOSPED/TIE 82.0/18.0 
transparent and 
Fragile 
1.5298 
crack-free for 
a long time 
Example 2 
APTMOS/TIE 82.5/17.5 
same as above 
Fragile 
1.5290 
Example 3 
TEOS/DEOMSP/TIE 
25.5/59.5/15.0 
same as above 
27 1.5210 
Example 4 
MTEOS/DEOMSP/TIE 
25.5/59.5/15.0 
same as above 
25 1.5186 
Example 5 
TMOPS/DEOMSP/TIE 
25.5/59.5/15.0 
same as above 
27 1.5189 
Example 6 
CLTMOS/DEOMSP/TIE 
25.5/59.5/15.0 
same as above 
30 1.5220 
Example 7 
TMOSPED/DEOMSP/TIE 
25.5/59.5/15.0 
same as above 
18 1.5190 
Example 8 
APTMOS/DEOMSP/TIE 
52.8/35.2/12.0 
same as above 
15 1.5211 
Example 9 
APTMOS/DEOMSP/TIE 
51.0/34.0/15.0 
same as above 
17 -- 
Comp. Example 1 
TEOS/TIE 88/12 cracked under 
-- 1.5264 
ambient conditions 
in a few days 
Comp. Example 2 
MTEOS/TIE 82/18 same as above 
-- 1.5227 
Comp. Example 3 
TMOPS/TIE 82/18 same as above 
-- 1.5199 
Comp. Example 4 
CLTMOS/TIE 82/18 same as above 
-- -- 
__________________________________________________________________________ 
TABLE III 
__________________________________________________________________________ 
Characteristics of gel-glass dispersed liquid crystals 
Gel-glass matrix 
Weight ratio 
Liquid crystal 
Initial 
Operation 
Response 
Example No. 
composition in part 
(E7) added (wt %).sup.a 
voltage (V) 
voltage (V) 
time (ms) 
__________________________________________________________________________ 
Example 10 
TMOSPED/TIE 82.0/18.0 
15 18 34 4.2 
Example 11 
APTMOS/TIE 82.5/17.5 
15 12 58 6.5 
Example 12 
TEOS/DEOMSP/TIE 
25.5/59.5/15.0 
50 6.5 16 9.4 
Example 13 
MTEOS/DEOMSP/TIE 
25.5/59.5/15.0 
30 4.5 26 8.6 
Example 14 
MTEOS/DEOMSP/TIE 
25.5/59.5/15.0 
50 4.5 11 8.9 
Example 15 
TMOPS/DEOMSP/TIE 
25.5/59.5/15.0 
50 3.5 17 9.5 
Example 16 
CLTMOS/DEOMSP/TIE 
25.5/59.5/15.0 
50 10 24 9.0 
Example 17 
TMOSPED/DEOMSP/TIE 
25.5/59.5/15.0 
15 10.5 26 6.5 
Example 18 
TMOSPED/DEOMSP/TIE 
25.5/59.5/15.0 
30 6 19 6.9 
Example 19 
TMOSPED/DEOMSP/TIE 
25.5/59.5/15.0 
50 3.5 12 11.2 
Example 20 
APTMOS/DEOMSP/TIE 
52.8/35.2/12.0 
15 12 23 6.5 
Example 21 
APTMOS/DEOMSP/TIE 
52.8/35.2/12.0 
30 7 15 7.2 
Example 22 
APTMOS/DEOMSP/TIE 
52.8/35.2/12.0 
50 2.5 4 18.6 
Example 23 
APTMOS/DEOMSP/TIE 
51.0/34.0/15.0 
50 5.5 13 16.8 
Comp. Example 5 
TEOS/TIE 88/12 15 .sup. --.sup.b 
.sup. --.sup.b 
-- 
Comp. Example 6 
MTEOS/TIE 82/18 15 -- -- -- 
Comp. Example 7 
TMOPS/TIE 82/18 15 -- -- -- 
Comp. Example 8 
CLTMOS/TIE 82/18 15 -- -- -- 
__________________________________________________________________________ 
.sup.a Based on the total weight of the components, i.e., total weight of 
the gelglass matrix and E7. 
.sup.b could not be determined.