3
`
`(N U] C)
`o
`
`CH \ (/4 x m(H «q4>
`
`S R
`SR
`
`0?
`0?
`
`996479157
`‘495479157
`
`4,647,157
`[11] Patent Number:
`Umted States Patent [19]
`4,647,157
`[1 1] Patent Number:
`Umted States Patent
`[19]
`Chiklis
`[45] Date of Patent:
`Mar. 3, 1987
`Chiklis
`'
`[45] Date of Patent:
`Mar. 3, 1987
`
`
`[54] FLUOROELASTOMERIC SEALANTS FOR
`[54] FLUOROELASTOMERIC SEALANTS FOR
`LIQUID CRYSTAL CELLS
`LIQUID CRYSTAL CELLS
`
`_
`
`_
`[75]
`Inventor: Charles K. Chiklis, Lexmgton, Mass.
`[75] Inventor:
`Charles K. Chiklis, Lexington, Mass-
`[73] Assignee: Polaroid Corporation, Cambridge,
`[73] Assignee:
`Polaroid Corporation, Cambridge,
`M .
`M .
`ass
`ass
`[21] Appl. No.: 678,113
`[21] Appl. No.: 678,113
`[22] Filed:
`Dec. 4, 1984
`[22] Filed:
`Dec- 4, 1984
`[51]
`Int. Cl.4 .............................................. G02F 1/133
`[51] Int. Cl.‘ ............................................ .. G02F 1/133
`
`[52] US. Cl. ........................... 350/343; 350/336
`[52] US. Cl. . . . . . . . . . . . . . . . . . .
`. . . . . . . .. 350/343; 350/336
`
`[58] Field of Search ............. 350/336, 347 E, 338,
`[58] Field of Search ........... .. 350/336, 347 E, 338,
`35o/397, 398, 343; 363/204
`350/397’ 398, 343; 368/204
`_
`_
`References C1ted
`References Clted
`U.S. PATENT DOCUMENTS
`U.S. PATENT DOCUMENTS
`2,968,649
`1/1961 Pailthorp et al.
`.................. 260/805
`2,968,649 1/1961 Pailthorp et a1. ................ .. 260/805
`3,700,306 10/1972 Cartmell et al. ............ 350/150
`3,700,306 10/1972 Cartmell a a1. .......... .. 350/150
`
`3,785,721
`1/1974 Harsch .................... 350/347 E
`3,785,721 1/1974 Harsch .................. .. 350/347 E
`
`3,835,463
`9/1974 Tsukamoto .
`350/333 X
`3,835,463 9/1974 Tsukamoto .
`350/333 X
`
`3,87l.746 3/ 1975 MUIO 6! al- -
`350/160 LC
`3,87l,746 3/ 1975 Muto et al.
`-
`350/160 LC
`
`
`3,914,017 10/1975 Bedell et a1.
`......... 350/398
`3,914,017 10/1975 Bedell et a1.
`....... .. 350/398
`3,994,568 11/1976 ng et al.
`.........
`.. 350/160 LC
`3,994,568 11/1976 King et a1. ....... ..
`350/160 LC
`
`4,012,119
`3/1977 'Adams et al. ................... 350/338
`
`4,012,119 3/1977 ‘Adams et a]. ................. .. 350/338
`4,217,035
`8/1980 Doriguzzi et al.
`.
`..... 350/338
`4,217,035 8/1980 Doriguzzi et a1. .
`350/338
`4,292,370
`9/1981 Pekko ............................. 350/337 X
`4,292,370 9/1981 Pekko ........................... .. 350/337 X
`
`[55]
`[56]
`
`4,494,825 1/1985 Sasaki et a1. . . . . . . .
`
`. . . . . . . .. 350/343
`
`4,466,742 8/ 1984 Lemelson ............................ 368/204
`4,466,742 8/ 1984 Lemelson .......................... .. 368/204
`4,482,213 11/1984 Piliavin et al.
`.
`..... 350/343 X
`4,482,213 11/1984 Piliavin et a1.
`. 350/343 X
`
`4,494,825
`1/1985 Sasaki et al.
`......... 350/343
`4,575,190
`3/1986 Wood et al.
`.................... 350/343 x
`4,575,190 3/1986 Wood et a1 .................. .. 350/343 X
`FOREIGN PATENT DOCUMENTS
`FOREIGN PATENT DOCUMENTS
`0181527 11/1982 Japan ................................... 350/343
`0181527 11/1982 Japan ................................. .. 350/343
`
`0644457
`7/1984 Japan
`..... 350/336
`0644457 7/1984 Japan .... ..
`OTHER PUBLICATIONS
`OTHER PUBLICATIONS
`Fluorel FT, trade bulletin Y—ITD 2481—1 of Commer-
`Fluorel FT, trade bulletin Y-ITD 2481-1 of Commer
`cial Chemicals Division/3M, St. Paul, MN, Dec. 1982.
`cia] Chemicals Division/3M, St, Paul, MN, Dec. 1982,
`_
`_
`_
`Primary Exammer—John K. Corbm
`Primary Examiner—John K. Corbm
`Assistant Examiner—David Lewis
`Assistant Examiner-—David Lewis
`Attorney, Agent, or Firm—Louis G. Xiarhos
`Attorney, Agent, or Firm-Louis G. Xiarhos
`[57]
`ABSTR AC1.
`[57]
`ABSTRACT
`.
`,
`.
`.
`,
`.
`.
`.
`.
`.
`f
`A “Clmd CTYSW CC“ comprlsmg 3 Pa" of opposed Plates
`A hqmd crystal cell c°mPnsm5a PaIr ° °PP°Sed_P_1ateS
`Spaced apart a Predetermined distance and containing 3
`Spaced apart a predetermmed dlstanc? and wntammg =1
`liquid crystal material confined therebetween by a fluo-
`liquid crystal material con?ned therebetween by a ?uo
`roelastomeric terpolymer sealant comprising repeating
`roelastomeric terpolymer sealant comprising repeating
`units of vinylidene fluoride, hexafluoropropylene and
`units of vinylidene ?uoride’ hexa?uoropropylene and
`tetrafluoroeth lene
`tetra?uoroeth lane
`y
`'
`y
`'
`
`,
`_
`18 Claims, 4 Drawing Figures
`18 Claims, 4 Drawing Figures
`
`
`
`/32'
`
`11 i
`
`32”
`
`IVI LLC EXHIBIT 2014
`
`XILINX V. IVI LLC _
`Inter Partes Review Case 2013—001 12
`
`

`

`U.S. Patent Mar. 3, 1987
`US. Patent Mar. 3, 1987
`
`Sheet 1 of 2
`
`Sheet 1 of 2
`
`4,647,157
`4,647,157
`
`2
`
`-
`
`1
`
`,
`
`2
`
`lllll
`
`Fl-G.2
`Fl-G.2
`
`l
`
`j
`
`
`

`

`U. S. Patent Mar. 3, 1987
`US. Patent Mar. 3, 1987
`
`Sheet20f2
`Sheet2of2
`
`4,647,157 ,
`4,647,157 7
`
`
`
`m
`
`\ M w llmL
`1 M“ 3, F .il‘ .
`
`llmw .
`
`- u ~ " m
`
`x - H ,.\.
`
`__ M i J. “A T
`
`//
`
`- w w I).
`
`

`

`1
`1
`
`4,647,157
`4,647,157
`
`FLUOROELASTOMERIC SEALANTS FOR LIQUID
`FLUOROELASTOMERIC SEALANTS FOR LIQUID
`‘
`CRYSTAL CELLS
`‘
`CRYSTAL CELLS
`
`5
`5
`
`10
`
`15
`
`25
`25
`
`30
`
`35
`
`2
`2
`BRIEF DESCRIPTION OF THE DRAWINGS
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a view in cross-section of a liquid crystal
`FIG. 1 is a View in cross-section of a liquid crystal
`cell ?lled with liquid crystal material and including a
`cell filled with liquid crystal material and including a
`sealant of ?uoroelastomeric terpolymer of the inven
`sealant of fluoroelastomeric terpolymer of the inven-
`tion.
`tion.
`FIG. 2 is a perspective view, partly schematic, of a
`FIG. 2 is a perspective view, partly schematic, of a
`liquid crystal display device embodying a liquid crystal
`liquid crystal display device embodying a liquid crystal
`cell as shown in FIG. 1 and adapted to permit the selec
`cell as shown in FIG. 1 and adapted to permit the selec-
`tive transmission of light.
`tive transmission of light.
`FIG. 3 is an exploded isometric view of a liquid crys
`FIG. 3 is an exploded isometric view of a liquid crys-
`tal display device of a preferred structure and including
`tal display device of a preferred structure and including
`a sealant of fluoroelastomeric terpolymer of the inven-
`a sealant of ?uoroelastomeric terpolymer of the inven
`tion.
`‘
`tion.
`'
`FIG. 4 is a side elevational view in cross section of
`FIG. 4 is a side elevational view in cross section of
`the liquid crystal display of FIG. 3.
`the liquid crystal display of FIG. 3.
`DETAILED DESCRIPTION OF THE
`DETAILED DESCRIPTION OF THE
`INVENTION
`INVENTION
`A liquid crystal cell of the invention having a ?uoro
`A liquid crystal cell of the invention having a fluoro-
`elastomeric terpolymer sealant is illustrated in FIG. 1
`elastomeric terpolymer sealant is illustrated in FIG. 1
`which, while not to scale, shows in cross section, a
`which, while not to scale, shows in cross section, a
`liquid crystal cell generally referred to therein by the
`liquid crystal cell generally referred to therein by the
`reference character 10. The liquid crystal cell 10 in
`reference character 10. The liquid crystal cell 10 in-
`cludes a pair of opposed plates 12 and 12’ spaced from
`cludes a pair of opposed plates 12 and 12' spaced from
`one another in a substantially parallel relationship.
`one another in a substantially parallel relationship.
`Plates 12 and 12' provide primary support for the liquid
`Plates 12 and 12’ provide primary support for the liquid
`crystal cell and can be composed of glass, plastic or like
`crystal cell and can be composed of glass, plastic or like
`transparent or translucent material. Shown on each of
`transparent or translucent material. Shown on each of
`plates 12 and 12' are transparent conductive layers 14
`plates 12 and 12’ are transparent conductive layers 14
`and 14‘. The transparent conductive layers 14 and 14’
`'
`and 14'. The transparent conductive layers 14 and 14' '
`may be of any conventional metal or metal oxide mate-
`may be of any conventional metal or metal oxide mate
`rial, including silver, gold or the known tin-oxide or
`rial, including silver, gold or the known tin-oxide or
`indium-oxide electroconductive coatings. In cell 10,
`indium-oxide electroconductive coatings. In cell 10,
`liquid crystal material 16 is shown between the plates
`liquid crystal material 16 is shown between the plates
`and is confined therebetween by seal 18 which com-
`and is con?ned therebetween by seal 18 which com
`prises a fluoroelastomeric terpolymer.
`'
`prises a ?uoroelastomeric terpolymer.
`'
`The ?uoroelastomeric terpolymer used in the devices
`The fluoroelastomeric terpolymer used in the devices
`of the present invention is a terpolymer of vinylidene
`of the present invention is a terpolymer of vinylidene
`?uoride, hexa?uoropropylene and tetra?uoroethylene
`fluoride, hexafluoropropylene and tetrafluoroethylene
`and, thus, is comprised of repeating units of the formu
`and, thus, is comprised of repeating units of the formu-
`las (I), (II) and (III), respectively:
`las (I), (II) and (III), respectively:
`
`BACKGROUND OF THE INVENTION
`BACKGROUND OF THE INVENTION
`This invention relates to a liquid crystal cell. More
`This invention relates to a liquid crystal cell. More
`particularly, it relates to a liquid crystal cell wherein the
`particularly, it relates to a liquid crystal cell wherein the
`liquid crystal material thereof is con?ned between op
`liquid crystal material thereof is confined between op-
`posed plates of the cell by a terpolymeric ?uoroelasto
`posed plates of the cell by a terpolymeric fluoroelasto-
`mer sealant.
`mer sealant.
`Liquid crystal cells used for the production of display
`Liquid crystal cells used for the production of display
`devices are well known and have been described in
`devices are well known and have been described in
`various patents and publications. In general, these cells
`various patents and publications. In general, these cells
`comprise a pair of opposed plates spaced apart at a
`comprise a pair of opposed plates spaced apart at a
`predetermined distance and contain a liquid crystal
`predetermined distance and contain a liquid crystal
`material con?ned therebetween. The liquid crystal ma
`material confined therebetween. The liquid crystal ma-
`terial is con?ned between the plates by a gasket or seal
`terial is confined between the plates by a gasket or seal-
`ant material which can be comprised of inorganic or
`ant material which can be comprised of inorganic or
`20
`organic material. Liquid crystal cells and examples of
`organic material. Liquid crystal cells and examples of
`20
`materials used as sealants or gaskets in the production
`materials used as sealants or gaskets in the production
`thereof are described, for example,
`in U.S. Pat. No.
`thereof are described, for example, in U.S. Pat. No.
`3,700,306 (issued Oct. 24, l972 to J. V. Cartmell et al.);
`3,700,306 (issued Oct. 24, 1972 to J. V. Cartmell et al.);
`in US. Pat. No. 3,871,746 (issued Mar. 18, 1975 to R.
`in U.S. Pat. No. 3,871,746 (issued Mar. 18, 1975 to R.
`Muto et al.; and in U.S. Pat. No. 3,994,568 (issued Nov.
`Muto et al.; and in US. Pat. No. 3,994,568 (issued Nov.
`30, 1976 to H. A. King et al.).
`30, 1976 to H. A. King et al.).
`The manufacture and operational efficiency of a liq
`The manufaéture and operational efficiency of a liq-
`uid crystal cell, or a display device prepared therefrom,
`uid crystal cell, or a display device prepared therefrom,
`can be in?uenced by the nature of the sealant or gasket
`can be influenced by the nature of the sealant or gasket
`material employed in the manufacture of the cell. Inor-
`material employed in the manufacture of the cell. Inor
`ganic materials such as glass and frit material have, for
`ganic materials such as glass and frit material have, for
`example, been employed as sealant materials for liquid
`example, been employed as sealant materials for liquid
`crystal cells. These materials are not readily processable
`crystal cells. These materials are not readily processable
`and generally require high temperatures for application
`and generally require high temperatures for application
`of the sealant material and provision of a suitable bond.
`of the sealant material and provision of a suitable bond.
`These temperatures are particularly disadvantageous
`These temperatures are particularly disadvantageous
`where the plates are desirably formed from a plastic
`where the plates are desirably formed from a plastic
`material such as polyester or the like. The more readily
`material such as polyester or the like. The more readily
`processable organic polymer sealant materials can also
`processable organic polymer sealant materials can also
`present difficulties in the fabrication of a liquid crystal
`present difficulties in the fabrication of a liquid crystal
`cell. For example, the integrity of the polymeric seal
`cell. For example, the integrity of the polymeric seal
`will oftentimes be sacri?ced over a period of time by
`will oftentimes be sacrificed over a period of time by
`chemical attack or degradation of the sealant material
`chemical attack or degradation of the sealant material
`by the liquid crystal material. This in turn can lead to
`by the liquid crystal material. This in turn can lead to
`swelling and softening of the sealant material and, in the
`swelling and softening of the sealant material and, in the
`case of gross failure, can lead to the formation and ap-
`case of gross failure, can lead to the formation and ap
`pearance of bubbles in the liquid crystal cell. The poly
`pearance of bubbles in the liquid crystal cell. The poly-
`meric sealant can also be a source of liquid crystal con-
`meric sealant can also be a source of liquid crystal con
`tamination as a consequence of diffusion of contami-
`tamination as a consequence of diffusion of contami
`nants from the polymeric sealant material into the liquid
`nants from the polymeric sealant material into the liquid
`crystal material con?ned between the opposing plates
`crystal material confined between the opposing plates
`of the cell. This can lead to inefficiency in the electrical
`of the cell. This can lead to inefficiency in the electrical
`operation of the cell and premature failure of the cell.
`operation of the cell and premature failure of the cell.
`SUMMARY OF THE INVENTION
`SUMMARY OF THE INVENTION
`It has been found that an effective seal for the con-
`It has been found that an effective seal for the con
`tainment of a liquid crystal material between spaced and
`tainment of a liquid crystal material between spaced and
`opposed plates can be provided by using as the sealant
`opposed plates can be provided by using as the sealant
`material, a ?uoroelastomer terpolymer of vinylidene
`material, a fluoroelastomer terpolymer of vinylidene
`fluoride, hexa?uoropropylene and tetra?uoroethylene.
`fluoride, hexafluoropropylene and tetrafluoroethylene.
`The fluoroelastomer can be applied to one or both of
`The ?uoroelastomer can be applied to one or both of
`the opposing plates and can be heat activated for provi
`the opposing plates and can be heat activated for provi-
`sion of a seal which is non'contaminating and which
`sion of a seal which is non-contaminating and which
`resists attack by the liquid crystal material, so as to
`resists attack by the liquid crystal material, so as to'
`permit the manufacture of a liquid crystal cell which
`permit the manufacture of a liquid crystal cell which
`exhibits desirable electrical performance over a pro-
`exhibits desirable electrical performance over a pro
`longed period of time.
`longed period of time.
`
`45
`
`50
`
`55
`55
`
`60
`60
`
`65
`65
`
`—CH2—CF2"'; CFr-CF and —CF2—CF2—
`—CH2—CF2"'; CFz—fF and —CF2—CF2—
`CF3
`CF3
`(II)
`(II)
`
`(III)
`(III)
`
`(I)
`(I)
`
`In general, the terpolymers used herein will contain
`In general, the terpolymers used herein will contain
`from 3% to 35% by weight of the tetra?uoroethylene
`from 3% to 35% by weight of the tetrafluoroethylene
`units; and from 97% to 65% by weight of vinylidene
`units; and from 97% to 65% by weight of vinylidene
`?uoride and hexa?uoropropylene units, the weight
`fluoride and hexafluoropropylene units,
`the weight
`ratio of vinylidene ?uoride to hexa?uoropropylene
`ratio of vinylidene fluoride to hexafluoropropylene
`units being in the range of from 2.33:1 to 0.67:1. The
`units being in the range of from 2.33:1 to 0.67:1. The
`weight ratio corresponds to a range of 70% to 40%.by_
`weight ratio corresponds to a range of 70% to 40%.by.
`weight of vinylidene ?uoride units and 30% to 60% by
`weight of vinylidene fluoride units and 30% to 60% by
`weight of hexa?uoropropylene units. Within this
`weight of hexafluoropropylene units. Within this
`weight ratio, the terpolymers are elastomeric.
`weight ratio, the terpolymers are elastomeric.
`Preferred ranges of repeating units in the terpolymers
`Preferred ranges of repeating units in the terpolymers
`hereof comprise from 15% to 25% by weight tetra?uor
`hereof comprise from 15% to 25% by weight tetrafluor-
`oethylene units; and from 85% to 75% by weight of
`oethylene units; and from 85% to 75% by weight of
`vinylidene ?uoride and hexa?uoropropylene units; the
`vinylidene fluoride and hexafluoropropylene units; the
`ratio of vinylidene ?uoride and hexa?uoropropylene
`ratio of vinylidene fluoride and hexafluoropropylene
`units being in the range of 2.33:1 to 0.67:1 by weight.
`units being in the range of 2.33:1 to 0.67:1 by weight.
`Fluoroelastomeric terpolymers particularly useful
`Fluoroelastomeric terpolymers particularly useful
`herein contain the following units: from about 15% to
`herein contain the following units: from about 15% to
`about 25% tetrafluoroethylene units; about 40% to 55%
`about 25% tetra?uoroethylene units; about 40% to 55%
`
`

`

`10
`
`15
`but 5
`
`25
`25
`
`30
`30
`
`4,647,157
`4,647,157
`3
`3
`4
`4
`vinylidene fluoride units; and about 30% to 35% hexa-
`vinylidene ?uoride units; and about 30% to 35% hexa
`sufficiently dissolved in appropriate solvent materials so
`sufficiently dissolved in appropriate solvent materials so
`?uoropropylene units. Fluoroelastomeric terpolymers
`fluoropropylene units. Fluoroelastomeric terpolymers
`to permit application to the surface or surfaces to be
`to permit application to the surface or surfaces to be
`suitable herein are commercially available. For exam-
`suitable herein are commercially available. For exam
`sealed. This can be accomplished, for example, by dis
`sealed. This can be accomplished, for example, by dis-
`solving the terpolymer in methyl propyl ketone, cyclo
`ple, good results are obtained using a ?uoroelastomeric
`ple, good results are obtained using a fluoroelastomeric
`solving the terpolymer in methyl propyl ketone, cyclo-
`terpolymer available from the Minnesota Mining and
`terpolymer available from the Minnesota Mining and
`hexanone or a mixture thereof. The resulting solution
`hexanone or a mixture thereof. The resulting solution
`Manufacturing Company under the trade designation
`Manufacturing Company under the trade designation
`can then be applied by coating, spraying, dipping or the
`can then be applied by coating, spraying, dipping or the
`Fluorel FF-2481 and having a fluorine level of about
`Fluorel FF-248l and having a ?uorine level of about
`like, such as by screen printing or gravure printing. The
`like, such as by screen printing or gravure printing. The
`67% by weight.
`67% by weight.
`coating solution can be applied, for example, at a thick-
`coating solution can be applied, for example, at a thick
`The terpolymers can be prepared by the copolymer
`The terpolymers can be prepared by the copolymer-
`ness of about 0.0005 to 0.001 inch (0.013 to 0.025 mm.)
`ness of about 0.0005 to 0.001 inch (0.013 to 0.025 mm.)
`ization in known manner of a mixture of the corre-
`ization in known manner of a mixture of the corre
`to the surface of one of the elements to be joined, and
`to the surface of one of the elements to be joined, and
`sponding monomers. An aqueous redox polymerization
`sponding monomers. An aqueous redox polymerization
`upon application of heat (e.g., 150°—l75° C.) can be
`upon application of heat (e.g., l50°-l75° C.) can be
`activated to an effective seal.
`system can be used and polymerization can be initiated
`system can be used and polymerization can be initiated
`activated to an effective seal.
`by resort
`to a conventional ammonium persulfate/-
`by resort to a conventional ammonium persulfate/
`The fluoroelastomeric terpolymer can be applied in
`The ?uoroelastomeric terpolymer can be applied in
`sodium bisul?te system. Polymerization will normally
`sodium bisulfrte system. Polymerization will normally
`various ways to the elements to be joined. For example,
`various ways to the elements to be joined. For example,
`be accomplished under pressure at moderately elevated
`be accomplished under pressure at moderately elevated
`a peripheral layer of sealant material can be applied to
`a peripheral layer of sealant material can be applied to
`temperatures. Suitable methods for the production of
`temperatures. Suitable methods for the production of
`opposite edge portions (on the same face) of one rectan-
`opposite edge portions (on the same face) of one rectan
`terpolymers useful herein are known and are described
`gular plate to be joined. A second rectangular plate,
`terpolymers useful herein are known and are described
`gular plate to be joined. A second rectangular plate,
`in greater detail in U.S. Pat. No. 2,968,649 (issued Jan.
`in greater detail in U.S. Pat. No. 2,968,649 (issued Jan.
`similarly provided with sealant material on opposite
`similarly provided with sealant material on opposite
`17, 1961 to J. R. Pailthorp et al.).
`17, 1961 to J. R. Pailthorp et al.).
`edges, can be interfaced orthogonally with the first
`edges, can be interfaced orthogonally with the ?rst
`The ?uorolastomeric terpolymer used to effect a seal
`plate, so that a seal is provided around four edges of the
`The fluorolastomeric terpolymer used to effect a seal 20 plate, so that a seal is provided around four edges of the
`between the elements of a liquid crystal cell and to
`joined cell. Alternatively, of one or both plates can be
`between the elements of a liquid crystal cell and to
`joined cell. Alternatively, of one or both plates can be
`confine the liquid crystal material therebetween has
`con?ne the liquid crystal material therebetween has
`printed with adhesive material, in the form of a periph
`printed with adhesive material, in the form of a periph-
`certain essential properties suited to this particular pur—
`certain essential properties suited to this particular pur—
`eral border or window, surrounding the liquid crystal
`eral border or window, surrounding the liquid crystal
`pose. The terpolymer shows resistance to attack by the
`pose. The terpolymer shows resistance to attack by the
`material. Other suitable applications of sealant material
`material. Other suitable applications of sealant material
`liquid crystal material. This property allows the cell to
`liquid crystal material. This property allows the cell to
`can be employed.
`can be employed.
`be used over a prolonged period without softening or
`be used over a prolonged period without softening or
`In FIG. 2 is shown a liquid crystal display device
`In FIG. 2 is shown a liquid crystal display device
`other structural impairment of the seal, leaking of liquid
`other structural impairment of the Seal, leaking of liquid
`formed from the liquid crystal cell of FIG. 1 by the
`formed from the liquid crystal cell of FIG. 1 by the
`crystal material from the cell, or undesirable permeation
`crystal material from the cell, or undesirable permeation
`external placement of polarizers on each side of the cell.
`external placement of polarizers on each side of the cell.
`of air and moisture into the cell through the impaired
`of air and moisture into the cell through the impaired
`The device of FIG. 2 comprises liquid crystal cell 10, as
`The device of FIG. 2 comprises liquid crystal cell 10, as
`seal.
`seal.
`shown in FIG. 1, sandwiched between crossed polariz
`shown in FIG. 1, sandwiched between crossed polariz-
`The fluoroelastomeric sealant used herein is noncon-
`The ?uoroelastomeric sealant used herein is non»con
`ers 20 and 20'. As shown, the polarization axes of polar
`ers 20 and 20'. As shown, the polarization axes of polar-
`taminating, i.e., deleterious substances are not diffused
`taminating, i.e., deleterious substances are not diffused
`izers 20 and 20’ are orthogonal with respect to one
`izers 20 and 20’ are orthogonal with respect to one
`therefrom into the liquid crystal material so as to ad-
`therefrom into the liquid crystal material so as to ad
`another. Light from light source 22 passes through
`another. Light from light source 22 passes through
`versely affect the proper functioning of the liquid crys
`polarizer 20 and is thereby plane polarized. When no
`versely affect the proper functioning of the liquid crys-
`polarizer 20 and is thereby plane polarized. When no
`35
`tal material in the operation of the cell. The preparation
`tal material in the operation of the cell. The preparation
`voltage is applied across conductive layers 14 and 14'
`voltage is applied across conductive layers 14 and 14’
`of the fluoroelastomeric terpolymer and the nature of
`of the ?uoroelastomeric terpolymer and the nature of
`liquid crystal cell 10 rotates the plane of polarization of
`liquid crystal cell 10 rotates the plane of polarization of
`the repeating units thereof are such as to allow compati
`the light passing therethrough by 90° which can then be
`the repeating units thereof are such as to allow compati-
`the light passing therethrough by 90" which can then be
`ble functioning of both the sealant and liquid crystal
`ble functioning of both the sealant and liquid crystal
`passed through polarizer 20' and received by the eye 24.
`passed through polarizer 20’ and received by the eye 24.
`Upon application of a voltage to conductive layers 14
`Upon application of a voltage to conductive layers 14
`components of the cell.
`i
`components of the cell.
`g
`The ?uoroelastomeric terpolymer is particularly use
`The fluoroelastomeric terpolymer is particularly use-
`and 14' (by means not shown), the capacity of the liquid
`and 14’ (by means not shown), the capacity of the liquid
`ful in exhibiting desirable adhesive and cohesive proper
`ful in exhibiting desirable adhesive and cohesive proper-
`crystal material in cell 10 to rotate the plane of polar
`crystal material in cell 10 to rotate the plane of polar-
`ties. In the production of plate elements for the contain
`ties. In the production of plate elements for the contain-
`ized light is lost, such that the plane polarized light
`ized light is lost, such that the plane polarized light
`ment of liquid crystal material
`therebetween,
`it
`is
`ment of liquid crystal material therebetween, it is
`passing through cell 10 is not passed by polarizer 20'
`passing through cell 10 is not passed by polarizer 20’
`(owing to the polarization axis thereof being orthogonal
`known to employ on each element, as a layer next adja-
`known to employ on each element, as a layer next adja
`(owing to the polarization axis thereof being orthogonal
`cent the liquid crystal material, a layer of material
`cent the liquid crystal material, a layer of material
`to the plane of polarized light impinged thereon). As a
`to the plane of polarized light impinged thereon). As a
`which serves to permit alignment of the liquid crystal
`which serves to permit alignment of the liquid crystal
`consequence, no transmission is observed by the eye 24.
`consequence, no transmission is observed by the eye 24.
`molecules in contact therewith, according to the orien-
`molecules in contact therewith, according to the orien
`While in FIG. 2, the polarizers 20 and 20' are shown
`While in FIG. 2, the polarizers 20 and 20’ are shown
`tation, as by pre-rubbing, of the alignment layer.
`tation, as by pre-rubbing, of the alignment
`layer.
`in a crossed relation to one another, the polarizers can
`in a crossed relation to one another, the polarizers can
`Among other materials, ?uorinated polymers, such as
`Among other materials, fluorinated polymers, such as
`be placed in parallel relation. In this event, there is no
`be placed in parallel relation. In this event, there is no
`50
`are described in detail in U.S. Pat. No. 4,066,814, can be
`transmission of light when no ?eld is applied to cell 10;
`are described in detail in U.S. Pat. No. 4,066,814, can be
`transmission of light when no field is applied to cell 10;
`used in the production of effective alignment layers. An
`used in the production of effective alignment layers. An
`and transmission is observed when a voltage is applied
`and transmission is observed when a voltage is applied
`to cell 10.
`example of a suitable alignment layer is a layer includ
`example of a suitable alignment layer is a layer includ-
`to cell 10.
`ing a mixture of chlorotri?uoroethylene/vinylidene
`ing a mixture of chlorotrifluoroethylene/vinylidene
`In FIG. 3 is shown an exploded isometric view of a
`In FIG. 3 is shown an exploded isometric view of a
`fluoride copolymer; polymethyl methacrylate; and
`preferred liquid crystal display device wherein polariz
`fluoride copolymer; polymethyl methacrylate; and
`preferred liquid crystal display device wherein polariz-
`vinylidine ?uoride/tetra?uoroethylene copolymer. It
`ers are incorporated into the device as internal ele-
`vinylidine fluoride/tetrafluoroethylene copolymer. It
`ers are incorporated into the device as internal ele
`has been found that the ?uoroelastomeric terpolymer
`has been found that the fluoroelastomeric terpolymer
`ment's, in contrast to the external placement of polariz
`ments, in contrast to the external placement of polariz-
`sealant adheres to a ?uoropolymer-containing align
`sealant adheres to a fluoropolymer—containing align-
`ers as shown in FIG. 2. In the display device of FIG. 3,
`ers as shown in FIG. 2. In the display device of FIG. 3,
`ment layer. This makes possible the formation by heat
`ment layer. This makes possible the formation by heat
`generally referred to by the reference character 30, are
`generally referred to by the reference character 30, are
`shown front and rear laminate assemblies 32 and 32’
`sealing of an effective bond between the sealant material
`sealing of an effective bond between the sealant material
`shown front and rear laminate assemblies 32 and 32’
`and a ?uoropolymer-containing alignment layer.
`and a fluoropolymer-containing alignment layer.
`which, when assembled together with a liquid crystal
`which, when assembled together with a liquid crystal
`The ?uoroelastomeric terpolymer, in addition, exhib
`The fluoroelastomeric terpolymer, in addition, exhib-
`material con?ned therebetween, form the completed
`material confined therebetween, form the completed
`its good cohesiveness. Thus, a layer, usually a periph
`its good cohesiveness. Thus, a layer, usually a periph-
`liquid crystal display. The front and rear assemblies 32
`liquid crystal display. The front and rear assemblies 32
`and 32’ may be constructed in identical fashion or one
`eral application, of sealant can be provided on each of
`eral application, of sealant can be provided on each of
`and 32' may be constructed in identical fashion or one
`the opposed plates, and upon contact of the opposing
`the opposed plates, and upon contact of the opposing
`or both may be modified depending upon the type of
`or both may be modi?ed depending upon the type of
`65
`surfaces of sealant and application of heat, an effective
`display desired to include a reflector or transreflector
`surfaces of sealant and application of heat, an effective
`65
`display desired to include a re?ector or transre?ector
`seal can be provided between the opposed plates.
`seal can be provided between the opposed plates.
`layer, as described more fully below.
`layer, as described more fully below.
`The laminate assemblies 32 and 32’ each include
`The ?uoroelastomeric terpolymer, while exhibiting
`The fluoroelastomeric terpolymer, while exhibiting
`The laminate assemblies 32 and 32’ each include
`desirable resistance to liquid crystal material, can be
`transparent substrates 34 and 34’ which provide primary
`transparent substrates 34 and 34’ which provide primary
`desirable resistance to liquid crystal material, can be
`
`60
`60
`
`40
`
`45
`45
`
`55
`55
`
`

`

`5
`5
`
`10
`
`20
`
`4,647,157
`4,647,157
`5
`5
`6
`6
`mechanical support for the completed liquid crystal
`mechanical support for the completed liquid crystal
`methods for the production of such polarizing materials
`methods for the production of such polarizing materials
`display. The substrates 34 and 34’ are preferably fabri
`display. The substrates 34 and 34’ are preferably fabri-
`are described in US. Pat. No. 2,445,555. The polarizing
`are described in US. Pat. No. 2,445,555. The polarizing
`cated from atransparent or translucent polyester such
`cated from atransparent or translucent polyester such
`layers hereof can be rea