JPH0216559A - Pattern forming material - Google Patents

Abstract

PURPOSE:To form a relief to the desired position on a substrate and to allow the manufacture of a high-density optical integrated circuit of a waveguide type nonlinear optical element, etc., by forming said circuit of a film formable liquid crystal consisting of a high-polymer liquid crystal compd. or said compd. and a non-liquid crystalline high-polymer compd. CONSTITUTION:The film formable liquid crystal includes the high-polymer liquid crystal compd., a mixture composed of the high-polymer liquid crystal compd. and a low-polymer liquid crystal compd., a mixture composed of the high-polymer liquid crystal compd. and the non-liquid crystalline high-polymer compd., a mixture composed of the low-polymer liquid crystal compd. and the non-liquid crystalline high-polymer compd., and a mixture composed of the high-polymer liquid crystal compd., the low-polymer liquid crystal compd. and the non-liquid crystalline high-polymer compd. The liquid crystal films having the desired shapes can be disposed to the desired positions on the substrate in this way and, therefore, the high-density integrated circuit for the waveguide type nonlinear optical element, liquid crystal optical element, etc., is produced on the substrate.

Description

[Detailed description of the invention] [Fields of use of M-Rakudo] The present invention relates to patterning materials.

[Prior Art] In recent years, materials have been studied for producing high-density optical integrated circuits such as waveguide type nonlinear optical elements by forming reliefs at desired positions on a substrate.

[Object of the present invention] An object of the present invention is to provide a liquid crystalline material that can be microfabricated.

[Means for Solving the Problems] The present inventors have arrived at the present invention as a result of intensive studies on materials that can form liquid crystal patterns.

That is, the present invention is a pattern forming material characterized by being made of a film-forming liquid crystal.

In the present invention, the film-forming liquid crystal includes (1) a polymer liquid crystal compound, (2) a mixture of a polymer liquid crystal compound and a low molecular liquid crystal compound, and (3) a polymer liquid crystal compound and a non-liquid crystal polymer compound. (4) a mixture of a low-molecular liquid crystal compound and a non-liquid crystalline polymer compound; and (5) a mixture of a high-molecular liquid crystal compound, a low-molecular liquid crystal compound, and a non-liquid crystalline polymer compound.

Examples of the polymer liquid crystal compound include a main chain type polymer liquid crystal compound, a side chain type polymer liquid crystal compound, and a main chain-side chain composite type polymer liquid crystal compound.

The main chain type polymer liquid crystal compound is a polymer compound in which mesogen is contained in the main chain, and may contain a flexible group (hereinafter referred to as a spacer) if necessary.

Examples of mesogens include those represented as 0X-o. Here, as X, CH=CH.

C-C, CH=CH-GO, Go-0, Go-NH.

vinegar etc.

Examples of the spacer include a methylene chain, an oxyethylene chain, an oxypropylene chain, and a dimethylsiloxane chain of CI'' CI*.

Examples of main chain type polymeric liquid crystal compounds include those having the following structural units as described in Macromolecular Hemi, Vol. 184, p. 253 (1983).

[CHI II-OQ-Co-0-o-C00'
-] (1) As other main chain polymeric liquid crystal compounds, polypeptides such as poly(γ-benzylglutamate) and cellulose derivatives such as hydroxypropyl cellulose can also be used.

A side chain type polymeric liquid crystal compound is one in which a mesogen is included in the side chain, and may be interposed between the main chain and the mesogen. In addition to those mentioned above, mesogens include those containing a cholesteryl group or a chiral nematic group. Examples of the main chain used in the side chain type polymeric liquid crystal compound include a C--C bond, a 5t-0 bond, and the like. An example of the former is Macromolecule Hemi-179.
Examples include those having a unit represented by the following chemical structure described in Vol. 2541 (1978).

Examples of the main chain-side chain composite polymer liquid crystal compound include those described in Macromolecular Hemi; Rapid Comics, Vol. 7, p. 389 (1988). Specifically, 1, as an example of the latter formula,
Examples include those having the following chemical structural unit described in JP-A No. 1-79173.

A polymer compound having a unit represented by:

Examples of low-molecular liquid crystal compounds include phenylbenzoic acid esters, biphenyl series and their esters, phenylcyclohexane series and their esters, cyclohexylcyclohexane series and their esters, phenyldioxane series and their esters, and phenylpyrimidine series. and esters thereof.

Further, in the present invention, the film-forming liquid crystal may be a ferroelectric liquid crystal, and such a liquid crystal may be a low-molecular compound containing a chiral alkyl group, specifically, a ferroelectric liquid crystal, such as a ferroelectric liquid crystal, such as a low-molecular compound containing a chiral alkyl group, specifically, "Liquid Crystal Basics" co-edited by Mitsuharu Okano and Ashibu Kobayashi. You can use the materials described in Chapter 7 of "Ed." (Baifukan, published in 1985). Also, tolans containing chiral alkyl groups (for example, Japanese Patent Application No. 11i1-43
No. 898 specification) can also be used. Furthermore, it is also possible to use a ferroelectric polymeric liquid crystal compound as shown in the following formula.

[-CN2CH-co C.O. In particular, ferroelectric liquid crystals are preferred for high-speed response displays.

The film-forming liquid crystal of the present invention contains a photocrosslinkable group.

Examples of the group that causes a photocrosslinking reaction include a radical polymerizable group, a photodimerizable group, an azide group, and a cationic polymerizable group.

Examples of the radically polymerizable group include an acrylate group, an α-chloroacrylate group, a methacrylate group, a styryl group, a vinyl group, a vinyl ester group, a vinyl ketone group, and an acrylamide group.

Examples of polymeric liquid crystal compounds containing such radically polymerizable groups include acrylic acid ester of hydroxypropyl cellulose described in Molecular Crystals & Liquid Crystals; Letters, Vol. 102, p. 255 (1984) and the following formula: Examples include those having the structural unit shown below.

Mention may be made of the lylacrylate group.

Examples of polymeric liquid crystal compounds containing such groups include those having a structural unit represented by the following formula.

Hs [wherein R1 is CH2CN2-OCOCH= CN2, -
CN is usually contained in a molar ratio of 100 to 40:100. Groups that photodimerize include a cinnamate group, a cinnamoyl group, a cinnamylidene acetate group, a cinnamylidene acetyl group, an α-cyanocinnamylidene acetate group, and an α-cyanocinnamylidene acetate group.
- Examples of polymeric liquid crystal compounds containing a cyanocinnamylideneacetyl group, a P-phenylene diacrylate group, and a 2-phazide group include those having a structural unit represented by the following formula.

[In the formula, R3 is 0-CO-CH=CH-o-N3 and Coo-orOCH3 temolar ratio usually l:100-40:
Included at a rate of 100). ] Examples of the cationically polymerizable group include an epoxy group, a vinyl ether group, an N-vinylcarbazole group, an indene group, and a coumaron group.

Preferred photocrosslinkable groups are acrylate and methacrylate groups.

There are no particular limitations on the non-liquid crystalline polymer compound as long as it is compatible with the liquid crystal compound. Specifically, vinyl resins such as vinyl chloride resin, acrylic resin, methacrylic resin, and styrene resin, and copolymers such as vinyl chloride-acrylic copolymer, as well as polyester resin, polycarbonate resin, polyurethane resin, etc. can be mentioned.

The non-liquid crystalline polymer compound may contain a crosslinkable group like the liquid crystalline polymer compound. Examples of the crosslinkable group include the same groups as those described for the polymeric liquid crystal compound, and preferred ones are also the same.

The crosslinkable group may be included in either the main chain or the side chain of the non-liquid crystalline polymer compound.

As the non-liquid crystalline polymer compound containing such a crosslinkable group, various polymer compounds that are practically used as photocurable resins can be used. Specific examples include triacrylate esters of triols obtained by addition-polymerizing many moles of propylene oxide to glycerin.

The film-forming liquid crystal may contain a group that exhibits nonlinear optical response. Such a group may be included in either a liquid crystal polymer compound or a non-liquid crystal polymer compound.

As a basis for nonlinear optical response, Applied Physics Vol. 57, 174
(1988). Examples of photocrosslinkable polymeric liquid crystal compounds containing such groups include copolymers having structural units represented by the following formula.

[In the formula, R4 is Not, 0CO-CH=CH*'t'. ] The non-liquid crystalline polymer compound that is film-forming is usually used, but it does not necessarily have to be film-forming as long as the liquid crystal is film-forming.

If necessary, various auxiliary agents such as a photoinitiator and a dye can be added to the film-forming liquid crystal in advance, or chemically bonded thereto.

Examples of photoinitiators for photocrosslinking include compounds described in "Photo/Radiation Curing Technology" (Taiseisha, 1985), p. 12, such as acetophenone, benzophenone, Michler's ketone, benzyl, benzoin, benzoin ether,
Mention may be made of benzyl ether, benzyl dimethyl ketal, thioxanthone and derivatives thereof.

In the present invention, an example of the formulation of the film-forming liquid crystal is as follows. % is by weight.

Normal liquid crystal 30-100% (polymer liquid crystal compound) 30-100 (low-molecular liquid crystal compound) 0-7゜Non-liquid crystal polymer compound O-F0 (when using a polymer liquid crystal compound) 0-50 0-30 (When no polymer liquid crystal compound is used) O~TO40~70 Photoinitiator 0~10 0~2 Preferably 5ON95% 50#95 0~40 0~70 Among the liquid crystals, the amount of polymer liquid crystal compound Usually 0-1 based on the total weight of molecular liquid crystal compound and low molecular liquid crystal compound
00%, preferably 50-100%.

According to the present invention, a film-forming liquid crystal is usually coated on a substrate, irradiated with light using a photomask between the substrate and a light source, and developed.

The substrate can be selected in consideration of thermal conductivity, mechanical strength, optical properties, flatness accuracy, etc., depending on the purpose of use. Examples of substrates include commonly used substrates such as glass, ceramics, plastics (acrylic resins, methacrylic resins, polycarbonate resins, polyolefin resins), and metals (such as aluminum).

The shape of the base body can be obtained in various ways depending on the purpose, for example,
Examples include plate shape, disk shape (round shape, drum shape, etc.).

In addition to coating a film-forming liquid crystal on a substrate according to the present invention,
It is also possible to form a film by the method for producing a stretched oriented film or the water surface spreading method described in No. 2-294657, and then transfer it to a substrate.

A method for spreading the film-forming liquid crystal on a water surface includes a method of dropping the solution onto the water surface. When the solution is added dropwise,
It immediately spreads on the water surface and forms a thin film.

The thickness of the film formed by casting and drying on the water surface is usually
It is 0.01-5 μm. By using a film-forming liquid crystal with a large molecular weight at a low concentration, an extremely thin film of about 0.1 μm can be easily created. It is also possible to create relatively thick films using highly concentrated solutions.

Depending on the purpose of the application, several to hundreds of water surface-deployable membranes can be stacked together. By doing so, a uniform and relatively thick film having a thickness of about 0.1 to 100 μm can be obtained.

When laminating on a substrate, an adhesive, an adhesive, or the like may be used to improve the adhesion between the film-forming liquid crystal and the substrate. As such, it is possible to use pressure-sensitive adhesives and adhesives commonly used for laminated films.

In the present invention, crosslinking is preferably carried out using light.

As this light, high-energy rays, usually ultraviolet rays, are used, but radiation such as electron beams and alpha rays may also be irradiated.

In the present invention, the pattern is formed by irradiating light with a photomask interposed, but the pattern may also be formed by laser scanning without a photomask.

After irradiation with light, the film is developed and washed with a suitable developer such as methyl ethyl ketone, xylene, or a mixed solvent of these and isopropyl alcohol or cyclohexane.
dry.

Thus, according to the present invention, it is possible to arrange a liquid crystal film of a desired shape at a desired position on a substrate.

[Example] Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited thereto.

Example 1 In order to synthesize a photocrosslinkable polymeric liquid crystal compound, first 4-
7-aryloxybenzoic acid trityl ester was obtained by reacting trityl chloride and 4-allyloxybenzoic acid in tetrahydrofuran (TIIF)-) diethylamine. 0.84 g of this trityl ester, 4-7 lyloxybenzoic acid-4'-cyanophenyl ester (CNSO
-3) An intermediate obtained from 2.23 g and 0.8 g of polymethylhydrosiloxane (31 g, 120 g) was treated with water/acetic acid to remove the trityl group. Next, trifluoroacetic anhydride and hydroxyethyl acrylate were reacted in sequence to obtain a photolinkable polymeric liquid crystal compound containing about 20 mol% of acrylate groups based on mesogenic groups.

Separately synthesized 4-(n-octyloxy)-benzoic acid-4
A toluene solution with a solid content of 1% was prepared from 30% of the polymer liquid crystal compound and 0.5% of the photoinitiator Irganox 184 (manufactured by Cipa Geigy).
The film-forming liquid crystal solution was gently dropped onto the wall of the water surface in a water tank to form a thin film on the water surface, which was scooped up and dried under vacuum at room temperature to obtain a water surface spread film of the pattern-forming material. After laminating 100 sheets of the membrane thus obtained on a Teflon plate, the membrane was fixed to a frame and then peeled off from the Teflon plate to prepare a composite membrane.

A pattern was printed by irradiating ultraviolet light (1, OJ/c+a2) using an ultraviolet irradiation device (manufactured by Ushioni Chikku Co., Ltd.). When developed with an I:l mixed solvent of methyl ethyl ketone and isopropyl alcohol, the polymer in the irradiated area remained, and a pattern with a film thickness of 6 μm was obtained at a desired position on the substrate with a resolution of about 25 μm.

Example 2 Optically active 2-methylbutanol, 4'-oxyphenyl-4-benzoic acid, 1,12-dibromododecane and acrylic acid were used as starting materials according to the method described in Proceedings of the Liquid Crystal Conference, page 150 (19117). We synthesized an optically active ferroelectric polymeric liquid crystal compound. On the other hand, 300 g of Sannix Polyol GP-300 (propylene oxide added to glycerin by an average of 3.8 moles, manufactured by Sanyo Chemical Industries, Ltd.), 25 g of Inphoron Diison Ane), 300 g of cyclohexanone
50 mg of 2-hydroxyethyl acrylate and hydroquinone monomethyl ether (o, tg) were charged into a Kolben and reacted at 75 to 85°C for 4 hours.
By reacting for a period of time, an oligomer solution having three acryloyl groups in one molecule was obtained.

After uniformly mixing 7.0 g of a ferroelectric polymeric liquid crystal compound, 0.7 g of an oligomer solution, and 0.1 g of benzoin methyl ether, a film of pattern forming material having a thickness of 60 μm was formed. This film was confirmed to have spontaneous polarization using the triangular wave method.

This film was irradiated with ultraviolet rays in the same manner as in Example 1, and the pattern was printed and developed to form the desired pattern on the substrate.

Example 3 Poly[fi-(4-nitrobiphenyloxy)hexyl methacrylate] synthesized by the method described in JP-A-82-201419 7. og1 1°5 g of the oligomer solution of Example 2 and 0.1 benzoin methyl ether
After uniformly mixing G, a film of pattern forming material with a thickness of 30 μm was formed.

In this film, a pattern similar to that in Example 1 could be formed on the substrate.

[Effects of the Invention] Since the pattern forming material of the present invention has liquid crystallinity, it has the following effects.

(This can be expected to have an extremely large effect on the production of high-density optical integrated circuits such as waveguide type nonlinear optical elements and liquid crystal optical elements on substrates.)

(2) Photo-crosslinkable film-forming liquid crystals exhibit high sensitivity to high-energy rays and can be efficiently patterned in a short period of time, making it unproductive to form indium tin oxide pattern electrodes on liquid crystal display cells. This process can be omitted.

Claims (1)

[Claims] 1. A pattern forming material comprising a film-forming liquid crystal. 2. The pattern forming material according to claim 1, wherein the film-forming liquid crystal is composed of a polymeric liquid crystal compound or this and a non-liquid crystal polymer compound. 3. Claim 1 in which the film-forming liquid crystal comprises a low-molecular liquid crystal compound, a polymer liquid crystal compound, and/or a non-liquid crystal polymer compound.
Or the pattern forming material according to 2. 4. The pattern forming material according to any one of claims 1 to 3, wherein the film-forming liquid crystal is a ferroelectric liquid crystal. 5, the film-forming liquid crystal has an acrylate group, a methacrylate group,
The pattern forming material according to any one of claims 1 to 4, comprising a radically polymerizable group selected from the group consisting of an α-chloroacrylate group, a styryl group, a vinyl group, a vinyl ester group, a vinyl ketone group, and an acrylamide group. 6. The film-forming liquid crystal has a cinnamate group, a cinnamoyl group,
Photodimerization selected from the group consisting of cinnamylidene acetate group, cinnamylidene acetyl group, α-cyanocinnamylidene acetate group, α-cyanocinnamylidene acetyl group, P-phenylene diacrylate group, and 2-furyl acrylate group The pattern-forming material according to any one of claims 1 to 5, which contains a group of . 7. Film-forming liquid crystal contains epoxy group, vinyl ether group, N
-Claim 1 containing a cationically polymerizable group selected from the group consisting of a vinylcarbazole group, an indene group and a coumaron group.
7. The pattern forming material according to any one of . 8. The pattern forming material according to any one of claims 1 to 3, wherein the film-forming liquid crystal exhibits a nonlinear optical response.