JP2798426B2 - Polarizing material and its suspension - Google Patents

Description

The present invention relates to a polarizing material, a solidified suspension thereof (set suspensio).
n) and liquid suspensions and light valves containing such liquid suspensions.

BACKGROUND OF THE INVENTION Polarizing materials such as colloidal suspensions of herapatite polarizing crystals and polarizing crystals similar to herapatite are disclosed in U.S. Pat.
No. 664 (Land) and No. 2,178,996 (Land), respectively. U.S. Pat. No. 2,237,567 (Land) describes the production of sheet-shaped polarizing material by various methods, including applying a solution of iodine and iodide to a sheet of polyvinyl alcohol that has been pre-stretched and oriented therein. Has been disclosed. Numerous other patents relating to polarizing materials, their solidified suspensions and laminated products derived therefrom and their uses, such as U.S. Pat.
041,138 (Land), 2,078,254 (Land), 2,168,220 (Land), 2,168,221 (Land), 2,185,018 (Sauer), 2,
230,262 (Pollack), 2,246,087 (Bailey et al.), 2,256,108 (Blake), 2,263,249 (Rogers)
s)), No. 2,306,108 (Land et al.), 2,328,219
(Land) and 2,375,963 (Thomas)
Patents including s)) exist in the art. GB 433,455 discloses the use of particles of pulpeocobalt-chloride sulfate periodide in the formation of polarizers. These and other patents mentioned herein are hereby incorporated by reference.

An important application of laminated solidified suspensions of polarizing materials, now often referred to as "sheet polarizers", is the use of polarized sunglass lenses, twisted nematics.
tic) type liquid crystal display components and various types of filters including contrast enhancing filters for use in combination with light emitting displays. However, the sheet polarizers used in this way have high levels of heat,
It is known that they are often decomposed due to UV radiation and / or especially moisture.

Liquid suspensions of polarizing materials and other materials are used in light valves that include cells containing liquid suspensions of fine particles that can be oriented by an electric or magnetic field to change the transmittance of light in the suspension. I was For example, U.S. Patent Nos. 3,708,219 (Forlini et al.), 3,743,382 (Rosenberg), 4,078,856 (Thompson et al.), And 4,113,362 (sax
e) et al., No. 4,164,365 (sax), 4,407,56
See No. 5 (Sax) and No. 4,422,963 (Thompson et al.).

US Patent No. 4,131,334 (Witte et al.)
It describes a process for producing polarized particles by hydrogenating a nitrogen-containing organic compound and then reacting with a suitable acid to form a salt. The salt may then usually react with iodine and inorganic iodide to form stable polyiodide particles.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polarizing material having high stability against ultraviolet light, high temperature and / or high level of moisture.

Polyhalides, including polyiodides, were often known. Polyiodide is a complex of iodine atoms with an inorganic or organic matrix. Godina et al. Discuss polyiodides and other polyhalides in detail in J. Gen. Chem. USSR, Vol. 20, (1950), pp. 1005-1016. Among the known polyiodides is the polarization crystalline material herapatite, which is formed by the reaction of quinine bisulfate, iodine and HI. Also,
Salts of other members of the quinine alkaloid family, such as cinchonidine bisulfate, produce polarized polyiodide upon reaction with iodine and HI. In these materials, I ₃ by elemental iodine (elementals iodine) is polyiodide of anion (which Godina et al ^- as, and Teiterubaumu (Teitelbaum) et (JACS, 100 vol (1978), 3215
The page ~3217) I ₅ ^- bind alkaloid acid salt in the form of have been variously described) as. Godinara the reaction between polyiodide of anions of iodine and HI, e.g. _{(1) I 2 + HI =} H + + I 3 - indicates that it is produced by. Similarly, I ₅ ^- polyiodide of anion reaction _{(2) 2H 2 + HI =} H + + I 5 - appears to be produced by.

Godina et al. Describe that the polarized polyiodide contains an acid salt such as quinine as the polyiodide anion and cation. However, polyiodides can be formed in the absence of obvious cations, such as starch-iodine complexes and stretched or oriented polyvinyl alcohol-iodine complexes. Teiterubaumura, the starch - including adsorption iodine chain forms of iodine in the amylase component of iodine complex starch, which chain I ₅ as the major species ^- reported as being made from polyiodide of anion I have. Godina et al. Theorize that herapatite, starch-iodine and oriented PVA-iodine complexes are "adsorbed polyiodides" in which molecular iodine is adsorbed in the upper layers of the polyiodide chains.

(Means for Solving the Problems) The polarizing material of the present invention comprises (i) elemental iodine, (ii) a hydrohalic acid and / or a halide of ammonium or an alkali metal or an alkaline earth metal, and (iii) Is a complex obtained by reacting the compounds of the formulas I to VI. This complex contains adsorbed molecular iodine. Godin et al. And Teitelbaum et al. Report that polyiodide anions are formed by the reaction between (i) elemental iodine and (ii) iodide, and the present inventors have determined that the above complex Kamata polyiodide anions, I _x ^- (wherein, x is 3 or 5
). In addition, Godina et al. Report that crystals containing adsorbed molecular iodine and polyiodide anions are polarizable.

In the following examples, the present inventors were able to prepare polarizing materials by reacting compounds of formulas I-VI with iodine and iodide, bromide or chloride. In such a case, each anion is as follows, using the structure revealed by Marks et al. As a model.

-II-I-I- -I-I-I-I-I-I-I-I-I-I-I- Godin et al. Have reported that a polarizing complex containing adsorbed molecular iodine has a structure. Report that it cannot be specified stoichiometrically by the formula. Therefore, the polarizing material of the present invention is specified as a product-by-process.

Compounds I to VI useful for producing the polarizing material of the present invention
Is as follows.

(Wherein R ¹ is carboxy, hydroxy, 2-pyridyl or lower alkyl substituted with carboxy or hydroxy, A is alkylene which forms a carbocyclic ring with the carbon atom shown in formula (VI), R ² is carboxy, hydroxy or lower alkyl substituted by carboxy or hydroxy, and R ³ and R ⁴ are independently hydrogen or lower alkyl. A may be alkylene of 3 to 8 carbon atoms. Preferably, it is alkylene of 3 to 5 carbon atoms, most preferably.

Also, the lower alkyl is preferably an alkyl having 1 to 4 carbon atoms.

Compounds I-IV are known per se or may be isomers, homologues or analogs of known compounds and may be prepared in a manner analogous to such known compounds.

Compounds I and IV containing a 2-pyridyl group can be formed analogously to the formation of 2,2'-dipyridyl.

 Useful compounds of Formulas I-VI include the following:

Compound 1-picolinic acid 2-2-hydroxypyridine 3-glycinic anhydride (2,5-piperazinedione) 4-barbituric acid 5-quinaldic acid 6-8-hydroxyquinoline 7-cycloleucine 8-2 , 2'-Dipyridyl The polarizing material according to the invention is prepared by reacting the compounds of the formulas I to VI with elemental iodine and hydrohalic acid and / or ammonium, alkali metal or alkaline earth in a suitable solvent such as alcohol or ether alcohol. It is produced by reacting with a metal halide. U.S. Patent No. 1,
See 951,661, 2,176,516 and 2,289,712. The halide is usually iodide, but may also be bromide or chloride. The reaction to form the polyhalide is preferably performed in the presence of a protective colloid, such as nitrocellulose or a copolymer, as disclosed in US Pat. No. 4,164,365 (registered Aug. 14, 1979). Compound I-VI in a first solution
And it is currently preferred to provide a mixture of iodine and a halide of ammonium or an alkali metal or alkaline earth metal in the second solution, but optionally the halide is present in either or both of these solutions. It may be. These solutions are then mixed together and the polyhalide is easily formed even at room temperature. The polarized polyhalide crystals are then recovered by a suitable technique such as filtration.

For light valve applications, the polyhalide particles are suspended in a liquid suspension medium. As is known, a liquid suspending medium suspends the particles and dissolves the polymeric stabilizer,
In practice, it may be an electrically resistive liquid. The liquid suspension medium preferably has a relatively high electrical resistivity and low vapor pressure, and does not decompose or attack the particles or other components of the suspension. For example, Sax U.S. Pat.
See 270,841 and 4,407,565.

For a solidified suspension, the polyhalide particles are dispersed or distributed in a sheet formed from a suitable film-forming material such as cellulose acetate or polyvinyl alcohol. For example, U.S. Pat.Nos. 2,178,996 and
See 2,041,138.

Examples 1 to 7 About 1.5 g of Compound 1 was dissolved in 13 g of a mixed solvent containing about 10 g of 2-ethoxyethanol and 3 g of methanol, and 1.3 g of iodine and 0.48 g of a 57% HI aqueous solution were dissolved. 10 g of the solution of n-propanol thus obtained. Blue polarized crystals were easily formed. The same operation was performed using Compounds 2 and 4 to 8 in place of Compound 1, and similar results were observed.

Examples 8-12 About 1.5 g of compound 1 was dissolved in 13 g of a solution containing 10 g of 2-ethoxyethanol and 3 g of methanol, and the solution was dissolved in 10 g of n-propanol in which 0.22 g of calcium iodide and 1.3 g of iodine were dissolved. Was mixed with the above solution. Blue polarized crystals were easily formed. Similar results were observed with quinaldic acid, barbituric acid, cycloleucine and 2,2'-dipyridyl, performing the same procedure.

Except for using the CaBr ₂ effective amount instead Examples 13 to 17 CaI _2, was repeated Example 8-12. Polarized crystals with a slightly different light blue color were readily formed.

Except for using the CaCl ₂ in an effective amount in place of Example 18 to 22 CaBr _2, Example
13-17 were repeated. Again, a polarizing crystal with a slightly different light blue color was easily formed.

Examples 23 to 27 About 1.5 g of Compound 1 was dissolved in 13 g of a solution containing 10 g of 2-ethoxyethanol and 3 g of methanol, and the solution was dissolved in about 0.58 g of potassium iodide (KI) in about 0.58 g of water. To a solution of 1.3 g of iodine in 10 g of n-propanol. Blue polarized crystals were easily formed. Similar results were observed with quinaldic acid, barbituric acid, cycloleucine and 2,2'-dipyridyl, performing the same procedure. Since the particles of the present invention were in fact created and dissolved in the presence of water,
These examples show that the grain water of the present invention is resistant to water and moisture.

Examples 28-32 Example 2 except that 0.62 g of CsI was used instead of 0.58 g of KI.
Repeating 3 to 27 gave similar results.

Although individual halides are used in the above examples, mixtures of halides, especially mixtures of iodides or mixtures of iodides with other halides, are used in such reactions, such as those described above. It can be used to advantage. For example, a CsI and CaI ₂ equimolar amounts in the solution is reacted with Kinarudo acid and I ₂ in the solution to produce a fine polarization crystals.

Example 33 Approximately 1 g of glycinic anhydride was 2,2,3,3-tetrafluoro-
Dissolved in 40 g of 1-propanol. Then the solution 1
g was dissolved in 1 g of calcium iodide and 2 g of iodine.
Mixed with 1 g of a solution consisting of 10 g of propanol. Small blue-violet polarized needle-like crystals were readily formed. These crystals were stable and did not decompose when dispersed in isopentyl acetate.

Comparative Example 34 About 1.5 g of 3-hydroxypyridine was dissolved in a mixed solvent containing 10 g of 2-ethoxyethanol and 3 g of methanol. The resulting solution was mixed with a solution of n-propanol in which iodine and hydroiodic acid were dissolved in the same amounts and according to the same procedure as in Examples 1-7. No polarizing crystals were formed.

The failure to produce polarized crystals in Comparative Example 34 using 3-hydroxypyridine is in sharp contrast to the success described above, instead using 2-hydroxypyridine under otherwise similar reaction conditions. The position of the hydroxy group and the longer distance from the ring nitrogen atom are the only significant differences that can explain the failure described in Comparative Example 34.

Some of the compounds I-VI of the present invention are known to form metal salts and / or are metal-chelating compounds. Thus, one possible explanation for the production of the polarizing material of the present invention is that when compounds I-VI are reacted with iodine and halide, the halide and iodine participate in the reaction in ionic form. For example,
Halide calcium iodide, if it is CaI _2, iodine Ca ⁺² (I _{x) 2} ^- can participate in the reaction as, the positively charged calcium ions chelated by compounds I through Vl, (I _x ) ^- anion is coupled to the positive calcium ion, thereby producing a polyiodide crystal. While this explanation seems reasonable, the inventors do not wish to be bound by this theory.

The liquid suspension of polyhalide particles of the present invention employs compounds I-VI of the present invention in place of dihydrocinchonidine sulfate and uses adjusted amounts of reactants, for example, as shown in the Examples above. Other than U.S. Pat.No. 4,131,33
It can be readily prepared by procedures somewhat similar to those for preparing a liquid suspension of dihydrocinchonidine sulfate polyiodide described in Example 2 of US Pat. No. 4,407,565 and Example 1 of US Pat. No. 4,407,565. .

Example 35 A. Preparation of quinaldic acid polyiodide (referred to as QAI) -nitrocellulose complex Solution A was prepared by dissolving 1.5 g of quinaldic acid in 13 g of a mixed solvent containing 10 g of 2-ethoxyethanol and 3 g of methanol. .

Solution B was a 40% solution of nitrocellulose in 2-ethoxyethanol. Nitrocellulose has low viscosity (18
~ 25cps) type.

 20 g of solution A and 20 g of solution B were mixed to form solution C.

Solution D was prepared by dissolving 0.22 g of anhydrous CaI _{2 in} 10 g of n-propanol, then adding 1.06 g of I ₂ and 22.0 g of tricresyl phosphate (referred to as TCP) and shaking for 15 minutes.

Solution C was combined with solution D in a Waring Blender with vigorous mixing while stirring with a polyethylene spatula along the inside wall of the cup, in the reverse direction of the flow of the blender. In a few seconds, a viscous wet paste with a blue color was produced. The wet paste was spread as an 8 mil film on a glass plate and dried in air for about 2 hours until no odor from volatile solvents could be detected.

B. Preparation of Liquid Suspension The dried paste was scraped from a glass plate, dispersed in 100 g of isopentyl acetate (referred to as IPA), and shaken well to disperse the paste to form a liquid suspension. 39 g of hexane is added to this suspension and shaken. The suspension was then sonicated for 10 hours and centrifuged at 2,500 rpm for 2 hours. Discard the sediment in the centrifuge tube.
Centrifuge for another 40 hours at pm. The sediment is then resuspended in IPA and an effective amount of a suitable polymer solution is added thereto. For example, a 10% 15% solution of a copolymer of neopentyl acrylate / methylol acrylamide (96.75% / 3.25%) dissolved in neopentyl neopentanoate.
15 g can be added. The new suspension is placed in a vacuum for about 5 hours to evaporate almost all of the IPA. Some of the other solvents present, which do not have too high a boiling point, can also evaporate. The suspension is then treated with halocarbon oil (Haloca
rbon Oil) 0.8 / 100 (Halocarbon Products (Hal
ocarbon Products) (Hackensack,
(New Jersey) and neopentyl neopentanoate to the desired degree to provide the desired off-state optical density and response time. Additional polymers may be added.

This type of quinaldic acid polyiodide suspension was tested at elevated temperatures with excellent results. Samples of these suspensions were placed in glass tubes at 85 ° C. for 66 hours with no substantial change in their performance.

Exposure of such suspensions to intense UV light has also produced excellent results. About 30cm from UV lamp (1
After about one month at a distance of about 1 ft., The test cell, which contained a suspension of quinaldolic acid polyiodide, showed no substantial change in its properties.

Liquid suspensions of the type described above may be used in light valves that utilize an alternating electric field to orient particles in the suspension to change and / or control the transmittance of light in the suspension. Such light valves can be used, for example, as variable transmission windows, filters, mirrors and glasses, and as electrical alphanumeric and graphic image displays.

However, by changing the composition of the suspension,
It is possible to produce what is known in the art as a solidified suspension, rather than a liquid suspension that can be used for the light valve described above. Solidified suspensions of the particles of the present invention include, for example, polarizing sheets or films in which the particles are mixed with other materials.

Many techniques for making polarizing sheets and films are known in the art. For example, U.S. Pat.
No. 6 produces certain types of polarizing particles, mixes the above particles in a dispersion medium that may include cellulose acetate, and then subjects the dispersion of particles to flow or extrusion or stretching or rolling, so that the dispersed Discloses a method in which the needle-like axes of a polarizing crystal can be oriented substantially parallel to produce a thin sheet-like polarizer. US Patent 2,041,
No. 138 discloses that the polarizer is preferably made in the form of a relatively thin sheet or film comprising a suspending medium and fine particles dispersed therein. If desired, the polarizer itself may be permanently or removably secured to a preferably transparent, suitable support, such as a glass plate or a sheet of celluloid. Such supports are desirable in conditions where the polarizer itself has been found to require some form of protection. Also, the above patent discloses the use of asymmetric particles, flowing a medium containing those particles past an edge, and holding the particles in an oriented position by solidifying or curing the medium. Is disclosed.

U.S. Pat. No. 2,168,220 is a trademark of Polaroid.
aroid) ", discloses the use of plasticizers, adhesives, and various types of laminates and methods of forming those laminates.

Numerous types of applications for polarizing films and polarizers are disclosed in U.S. Pat.No. 2,246,087, which applications include, for example, windshields, windows, glasses, goggles, sunglasses, camera lenses, microscopes, mirrors, and Includes applications related to stereoscopic movies.

A method for transferring a polarizing film from one support to another and various materials used in connection therewith are disclosed in U.S. Pat. No. 2,256,108.

Using information available from any of the above patents and from many other patents and other sources known in the art, a polarized solidified suspension comprising particles oriented substantially parallel, Films and sheets, and polarizers and articles made therefrom, can be made.

However, many polarizers used commercially today do not incorporate films or sheets having parallel discontinuous particles of solids oriented therein, rather, U.S. Patent Nos. 2,237,567 and 2,375,963. And has substantially its optical axis in the plane of the sheet as described in US Pat. Use a sheet of polyvinyl alcohol polyiodide that does not transmit. Commercially available polarizers are known to be susceptible to degradation upon prolonged exposure to harsh environmental conditions such as high temperature, high humidity, ultraviolet light, and especially combinations of such conditions.

Despite the problems associated with the environmental degradation of commercial sheet polarizers, rather than using multiple individual polarizing crystals as described above, a stretched sheet of polymer is reacted with a dye or colorant, or reacted with iodine and iodide. The reaction is preferable and sometimes desirable from the viewpoint of production. To this end, useful embodiments of the present invention also include those compounds of the present invention that also include compounds wherein each molecule of compounds I-VI has a polymerizable unsaturated group attached thereto.
These compounds are monomers such as 4-vinylpicolinic acid and 4-vinyl-2-hydroxypyridine, which can be polymerized by known techniques to form sheets similar to polyvinyl alcohol, It can be reacted with various dyes or colorants or with iodine and halides to produce polyiodides or other types of polarizers as in the prior art.

However, polarizers made from solidified suspensions of the particles and other materials of the present invention are extremely stable to high levels of heat and ultraviolet light and, as noted, have excellent water resistance. Thus, the present invention allows for a considerable improvement in the quality of polarizers and products incorporating such materials.

While particular embodiments of the present invention have been described, it is understood that many modifications that fall within the spirit and scope of the invention may be made by those skilled in the art.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-86858 (JP, A) JP-A-58-107505 (JP, A) JP-A-3-167290 (JP, A) JP-A-62 270664 (JP, A) JP-A-63-49705 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G02B 1/08, 5/30

Claims (6)

(57) [Claims] 1. An elemental iodine, (ii) a hydrohalic acid and / or a halide of ammonium or an alkali metal or an alkaline earth metal, and (iii) (Wherein R ¹ is carboxy, hydroxy, 2-pyridyl,
Or lower alkyl substituted by carboxy or hydroxy, A is alkylene which forms a carbocycle with the carbon atom indicated in formula (VI), and R ² is carboxy, hydroxy or substituted by carboxy or hydroxy. Wherein R ³ and R ⁴ are independently hydrogen or lower alkyl), the compound having an adsorbed molecular iodine. Polarizing material. 2. The polarizing material according to claim 1, wherein the hydrohalic acid and / or the halide of ammonium or alkali metal or alkaline earth metal is chloride, bromide or iodide. 3. The method according to claim 1, wherein said compound is picolinic acid, 2-hydroxypyridine, glycic anhydride, barbituric acid, quinaldic acid, 8-hydroxyquinoline, cycloleucine or
2. The polarizing material according to claim 1, wherein the polarizing material is 2,2'-dipyridyl. 4. An electrically resistive liquid suspending medium, a plurality of small irregularly shaped particles of a polarizing material according to claim 1, dispersed therein, and said suspension. A liquid suspension for a light valve, characterized by at least one dispersant dissolved therein for dispersing said particles in a suspension. 5. The method according to claim 1, wherein the carrier is dispersed in a carrier.
A polarizer comprising a large number of particles of the polarizing material according to (2) or (3), wherein the polarization axes of the particles are oriented substantially parallel by the carrier and held immobile. 6. A cell comprising a suspension of the polarizing particles of the polarizing material according to claim 1, suspended in a liquid suspension medium. Light valve.