US4673255A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of controlling microdroplet growth in polymeric dispersed liquid crystal
Assignee: Kent State University
•
Filing: 1986-06-27
•
Granted: 1987-06-16
•
Expires: 2006-06-27
Abstract
Abstract The invention provides a method of controlling the rate of growth of liquid crystal microdroplets formed in situ by the phase separation of a homogeneous solution of liquid crystal and polymer. Temperature, relative concentration and choice of materials determine the microdroplet growth rate and resultant microdroplet size and density. Controlling growth rate allows for fabrication of liquid crystal display devices with optimized display characteristics and response times.
Inventors
- 👤 John West
- 👤 Attilio Golemme
- 👤 Joseph W. Doane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:51
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1334; C; C09; C09K; C09K19/00; C09K19/52; C09K19/54; C09K19/542; C09K19/544
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
47 words
In a method of making liquid crystal microdroplets dispersed in a polymeric matrix by phase separating a homogeneous solution of liquid crystal and polymer, the improvement comprising the step of controlling microdroplet growth so that the microdroplets have a selected average diameter when phase separation is complete.
Claim 2
Dependent Claim
47 words
In a method of making liquid crystal microdroplets dispersed in a polymeric matrix by phase separating a homogeneous solution of liquid crystal and polymer, the improvement comprising the step of controlling microdroplet growth so that the microdroplets have a selected average diameter when phase separation is complete.
Claim 3
Dependent Claim
36 words
The improvement as claimed in claim 1 wherein the homogeneous solution comprises a curable synthetic polymer and liquid crystal and wherein the step of controlling microdroplet growth is carried out by controlling the rate of curing.
Claim 4
Dependent Claim
31 words
The improvement as claimed in claim 2 wherein controlling the rate of curing is carried out by selecting a curable synthetic polymer having a predetermined curing rate at a given temperature.
Claim 5
Dependent Claim
27 words
The improvement as claimed in claim 3 including the further step of adjusting the temperature at which curing occurs to accelerate or retard the rate of curing.
Claim 6
Dependent Claim
17 words
The improvement as claimed in claim 4 wherein the temperature is about room temperature to 80° C.
Claim 7
Dependent Claim
25 words
The improvement as claimed in claim 4 wherein the temperature is adjusted to yield microdroplets having an average diameter of about 0.1 to 8 microns.
Claim 8
Dependent Claim
23 words
The improvement as claimed in claim 2 wherein controlling the rate of curing is carried out by adjusting the intensity of ultraviolet radiation.
Claim 9
Dependent Claim
27 words
The improvement as claimed in claim 2 wherein the step of controlling the rate of curing is carried out by adjusting the temperature of which curing occurs.
Claim 10
Dependent Claim
26 words
The improvement as claimed in claim 1 wherein the step of controlling microdroplet growth is carried out by adjusting the ratio of liquid crystal to polymer.
Claim 11
Dependent Claim
24 words
The improvement as claimed in claim 9 in which the ratio of liquid crystal to polymer is about 1:9 to about 1:1 by weight.
Claim 12
Dependent Claim
17 words
The improvement as claimed in claim 10 wherein the temperature is about room temperature to 80° C.
Claim 13
Dependent Claim
25 words
The improvement as claimed in claim 10 wherein the temperature is adjusted to yield microdroplets having an average diameter of about 0.1 to 8 microns.
Claim 14
Dependent Claim
48 words
The improvement as claimed in claim 1 wherein the homogeneous solution comprises liquid crystal and thermoplastic polymer heated to a temperature sufficient to dissolve the liquid crystal and wherein the step of controlling microdroplet growth is carried out by controlling the rate of cooling of the heated solution.
Claim 15
Dependent Claim
20 words
The improvement as claimed in claim 13 wherein the rate of cooling is about 0.2° to 4° C. per minute.
Claim 16
Dependent Claim
27 words
The improvement as claimed in claim 13 wherein the rate of cooling is effective to yield microdroplets having an average diameter of about 0.1 to 8 microns.
Claim 17
Dependent Claim
23 words
The improvement as claimed in claim 1 wherein the ratio of liquid crystal to polymer is about 1:9 to about 1:1 by weight.
Claim 18
Dependent Claim
30 words
The improvement as claimed in claim 1 wherein the step of controlling microdroplet growth is carried out by adjusting the rate of evaporation of a solvent from the homogeneous solution.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-15 | 1990-12-15 | 1991-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-15 | 1994-12-15 | 1995-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-15 | 1998-12-15 | 1999-06-16 | $7700.00 | Window Closed / Lapsed |