JPH10204433A - Container for storing liquid crystal material and storage of liquid crystal material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a container for storing a liquid material capable of preventing the deterioration of a liquid crystal compound containing fluorine atoms, etc., capable of maintaining a high specific resistance value, and suitable for carrying the liquid crystal by constituting a resin layer formed on the inner side brought into contact with the liquid material. SOLUTION: This container has at least two layers comprising a resin layer, such as a polypropylene layer, formed on the inner side brought into contact with a liquid crystal material such as a compound of the formula (R<1> is a 1-5C alkyl; A is a single bond, trans-1,4-cyclohexylene; R<2> is F, Cl, cyano, a 1-5C alkyl; ph is 1,4-phenylene) and a metal layer, such as an aluminum layer, formed on the outside of the resin layer. A liquid crystal is preferably stored in the container.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a container for storing a liquid crystal material and a method for storing a liquid crystal material using the container. The container for storing a liquid crystal material of the present invention is suitable for storing and transporting a liquid crystal material, and is particularly a container that can prevent deterioration of a liquid crystal compound containing a fluorine atom and the like and can maintain a high specific resistance value.

[0002]

2. Description of the Related Art In recent years, as one of typical liquid crystal display devices, there is a TN-LCD (Twisted Nematic-Liquid Crystal Display Device), which is used in watches, calculators, pocket computers, word processors, personal computers and the like. I have.

[0003] The amount of information displayed on these screens is increasing more and more.
There is a problem that it is not possible to meet a demand for high time-division driving from the viewpoint of display quality such as a viewing angle. As an element for solving these problems, STN-LCD (Super Twisted Nematic-Liquid Crystal Display Element) has been developed by Shepher et al. And has been used for display for advanced information processing using high time division driving.

[0004] In the STN-LCD, an afterimage phenomenon,
The display screen flickers due to the inability of the liquid crystal molecules to follow the field effect mode of the high time division drive has become a problem. In order to solve these problems, it is necessary to keep the specific resistance of the liquid crystal material at a high level.

Further, in the STN-LCD, high-speed response and low-voltage driving are demanded. As a method of increasing the response speed, a method of reducing the viscosity of a liquid crystal material can be cited. For this purpose, attempts have been made to develop a liquid crystal compound having a fluorine atom introduced into a molecule. It is known that difluorostilbene type liquid crystal exhibits extremely low viscosity physical properties as the liquid crystal compound (US Pat. No. 5,380,461).
issue). Further, the difluorostilbene type liquid crystal is expected to be used in other display elements for which a high-speed response is desired, for example, an active matrix type liquid crystal display element such as a TFT-LCD or an MIM-LCD.

As a method of achieving low voltage driving, low voltage driving has been attempted by introducing a fluorine atom or the like in the molecular axis direction of a liquid crystal compound to obtain a liquid crystal material having a large dielectric anisotropy. ing. For example, 4-cyano-3,5-difluorophenyl esters have been proposed as a liquid crystal compound having a large dielectric anisotropy. But,
Most of the compounds proposed as liquid crystal materials capable of achieving high-speed response and low-voltage driving have low stability to oxygen, moisture, and light. There was a need for a storage container that could maintain a high level of resistance.

At present, a glass container made of neutral borosilicate glass, soda lime glass, non-alkali glass or the like, which is considered to be excellent in heat resistance and chemical durability, is known for storing or transporting a liquid crystal material. ing. Further, a method of improving the chemical durability by overcoating the inner surface of a container made of these materials with SiO ₂ is also performed.

[0008]

However, in the case of difluorostilbene type liquid crystals and fluorine-containing liquid crystals such as fluorophenyl esters, trace amounts of water contained in the liquid crystal material,
Alternatively, the water mixed for other reasons may cause the C-
It is considered that HF reacts with part F to generate HF, and the following reaction occurs on the surface of the container.

SiO ₂ + 4HF → SiF ₄ + H ₂ O

Further, it is considered that the produced water reacts again with the C-F portion of the fluorine-containing liquid crystal, and subsequently lowers the purity and specific resistance of the liquid crystal material. Therefore, the conventional container has a problem that the liquid crystal compound cannot be stably stored.

[0011]

SUMMARY OF THE INVENTION The present invention provides an STN-LC
The object of the present invention is to provide a container capable of stably storing a liquid crystal compound used for a liquid crystal element such as D or TFT-LCD, particularly a fluorine-containing liquid crystal compound.

That is, the present invention is characterized by comprising a container having at least two layers of a resin layer formed inside and a metal layer formed outside the resin layer in contact with the liquid crystal material. Provided is a container for storing a liquid crystal material.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The container according to the present invention has at least two layers of a resin layer formed inside and in contact with a liquid crystal material, and a metal layer formed outside the resin layer.

Examples of the resin layer include layers made of a resin such as polyethylene, polypropylene, polyvinyl chloride, regenerated cellulose (eg, cellophane (trade name)), and polycarbonate, and a layer made of polyethylene or polypropylene is preferable. The thickness of the resin layer is 10
100 μm is preferred.

[0015] A metal layer is formed outside the resin layer. Examples of the metal layer include a layer made of aluminum, tin, silver, copper, zinc, lead, or the like, and a layer made of aluminum is preferable. The thickness of the metal layer is preferably 5 to 70 μm.

The container of the present invention has at least two layers of the above resin layer and metal layer. When more than two layers are formed, a resin layer is formed outside the metal layer, a metal layer is formed outside the resin layer, and so on. Preferably.

Further, the container of the present invention preferably has two layers composed of a resin layer and a metal layer, or three layers composed of a resin layer, a metal layer and a resin layer. Are preferred. The resin layer and the metal layer in the container of the present invention are preferably laminated (laminated). Examples of the bonding method include bonding and thermocompression bonding.

The shape of the container of the present invention is not particularly limited, and examples thereof include a bag shape, a box shape, and a bottle shape.
It is preferably in the form of a bag. The openings of these containers into which the liquid crystal material is inserted may be brought into close contact by a method such as welding after the liquid crystal material has been charged. Before the contact is made, it is preferable to perform an operation such as purging with nitrogen or making a vacuum state in order to remove oxygen which causes decomposition of the liquid crystal material.

When it is desired to take the liquid crystal material in and out of the container, it is preferable that the container port is of a screw cap type or a screw port type. However, the screw cap or the screw portion has two or more layers in the present invention,
Since there is technical difficulty and it is not economical, this portion may be formed only of resin.

When the container port is of a screw-hole type or a screw-hole cap structure, it is difficult to prevent the permeation of water vapor or oxygen, so that the resin layer formed on the inside which comes into contact with the liquid crystal material, A container having at least two metal layers formed outside the resin layer (hereinafter also referred to as a first container) is preferably placed in a second container described below having a larger inner volume than the container. preferable.

Second container: a container having at least two layers of a resin layer formed inside and a metal layer formed outside the resin layer in contact with the first container.

It is preferable that the container opening of the second container is welded and adhered. The second container also preferably has two layers consisting of a resin layer-metal layer, or three layers consisting of a resin layer-metal layer-resin layer, and particularly three layers consisting of a resin layer-metal layer-resin layer. Is preferred. By permeating the first container in the second container, the permeation of water vapor and oxygen can be almost completely blocked. Further, it is particularly preferable to insert an oxygen absorbent and / or a moisture absorbent between the first container and the second container, since the water vapor and the oxygen can be further removed.

The liquid crystal material stored in the liquid crystal material storage container of the present invention includes a liquid crystal compound, a liquid crystal composition containing two or more liquid crystal compounds, a liquid crystal composition of a liquid crystal compound and a non-liquid crystal compound, and a liquid crystal material. There are no particular limitations on the additives used for the addition, and various types can be mentioned.

Of these, a liquid crystal compound, a liquid crystal composition containing two or more liquid crystal compounds, or a liquid crystal composition of a liquid crystal compound and a non-liquid crystal compound is particularly preferable. Further, in any of these, the liquid crystal compound preferably contains a fluorine-containing liquid crystal compound. As the fluorine-containing liquid crystal compound,
The compound represented by the following formula 1 is preferred. The -CF = CF- moiety in the compound preferably has a transdifluoroethylene structure.

[0025]

R ¹ -A-Ph-CF = CF-Ph-R ² Formula 1

However, the symbols in the formula 1 have the following meanings. R ¹ : an alkyl group having 1 to 5 carbon atoms. A: A single bond or a trans-1,4-cyclohexylene group. R ^{2 represents a} fluorine atom, a chlorine atom, a cyano group, or an alkyl group having 1 to 5 carbon atoms, and in the case of an alkyl group, an oxygen atom, a trans double bond, or a triple bond between carbon-carbon bonds. May be included, and an etheric oxygen atom may be inserted between itself and Ph. Ph: 1,4-phenylene group.

Specific examples of the compound represented by the above formula 1 include the following compounds. However, the symbols in the formula 1 have the same meaning as described above, and Cy is trans-1,4-
Shows a cyclohexylene group.

[0028]

CH ₃ -Ph-CF = CF-Ph-Cl CH ₃ -Ph-CF = CF-Ph-F CH ₃ -Ph-CF = CF-Ph-CN CH ₃ -Ph-CF = CF-Ph _{-CH 3 CH 3 -Ph-CF =} CF-Ph-OCH 3 CH 3 CH 2 -Ph-CF = CF-Ph-F CH 3 CH 2 CH 2 -Ph-CF = CF-Ph-F CH 3 CH = CHCH ₂ CH ₂ Ph-CF = CF-Ph
_{-F CH 3 CH 2 -Ph-CF} = CF-Ph-CH 3 CH 3 CH 2 -Ph-CF = CF-Ph-OCH 3 CH 3 CH 2 -Ph-CF = CF-Ph-OCH 2 CH 3 CH _{3 -Cy-Ph-CF = CF} -Ph-Cl CH 3 -Cy-Ph-CF = CF-Ph-F CH 3 -Cy-Ph-CF = CF-Ph-CN CH 3 -Cy-Ph-CF = _{CF-Ph-CH 3 CH 3} -Cy-Ph-CF = CF-Ph-OCH 3 CH 3 CH 2 -Cy-Ph-CF = CF-Ph-CH 3 CH 3 CH 2 -Cy-Ph-CF = CF -Ph-OCH
_{3 CH 3 CH 2 -Cy-Ph} -CF = CF-Ph-OCH
₂ CH ₃

The liquid crystal material storage container of the present invention can store the liquid crystal material much more stably than the conventional glass container. In particular, the purity and specific resistance value of the fluorine-containing liquid crystal material stored in the container can be improved. Is small and can be stored for a long period of time. Further, the container is a container excellent in versatility since there is no problem in ordinary movement or transportation.

[0030]

【Example】

[Preparation of Liquid Crystal Composition A] 10% by weight of a compound represented by the following formula 2, 10% by weight of a compound represented by the following formula 3, 10% by weight of a compound represented by the following formula 4, a commercially available liquid crystal manufactured by Merck Ltd. A liquid crystal composition (hereinafter, referred to as liquid crystal composition A) containing 70% by weight of the composition [trade name: ZLI-1565] was prepared.
The liquid crystal composition A has a nematic phase-isotropic liquid phase transition temperature (T _ni ) of 81 ° C., a threshold voltage (V _th ) of 2.6 V,
Dielectric anisotropy (△ ε) is 6.6, refractive index anisotropy (△ n)
Was 0.165 and the specific resistance was 4.0 × 10 ¹³ Ω / cm ² .

[0031]

Embedded image

[Preparation of Liquid Crystal Composition B] 10% by weight of a compound represented by the following formula 2, 10% by weight of a compound represented by the following formula 3, 10% by weight of a compound represented by the following formula 4, and 5% by the following formula A liquid crystal composition (hereinafter, referred to as a liquid crystal composition B) containing 10% by weight of a compound represented by the following formula and 60% by weight of a commercially available liquid crystal composition (trade name: ZLI-1565) manufactured by Merck Ltd. was prepared.
The clearing point (T _ni ) of the liquid crystal composition B was 72 ° C., and V _th was 1.
9V, Δε was 13.0, Δn was 0.167, and specific resistance was 4.0 × 10 ¹² Ω / cm ² .

[0033]

Embedded image

[Container (a)] Polyethylene-aluminum foil-
A 100 ml container of a pouch "made by Fujimori Kogyo Co., Ltd." with a spout (polyethylene screw port) made by welding sheets laminated in the order of polyethylene was prepared.

[Container (b)] Polyethylene-aluminum foil-
A container “made by Fujimori Kogyo Co., Ltd.” was prepared by welding an aluminum laminated sheet laminated in the order of polyethylene to form a bag.

Example 1 50 parts of the liquid crystal composition A were placed in the container (a).
g, replace with nitrogen, and store in a 50 ° C constant temperature bath.
For the time indicated. Table 1 shows the results of measuring the specific resistance (unit: Ω / cm ² ) of the liquid crystal composition after storage. In addition,
Storage in a 50 ° C. thermostat corresponds to about eight times the storage time at room temperature (20 ° C.).

Example 2 The container (a) containing the liquid crystal composition A in Example 1 was further placed in the container (b) and stored under the same conditions, and the specific resistance value after storage (unit: Ω / cm ² ) was measured. Table 1 shows the results.

Example 3 Between the container (a) and the container (b) in Example 2, "Mitsubishi Gas Chemical Co., Ltd., trade name: RP-2" was used as a deoxygenating / dehydrating agent (c). Insert one and save under the same conditions, and the specific resistance value after storage (unit: Ω / cm
² ) was measured. Table 1 shows the results.

[Examples 4 to 6] The liquid crystal composition B was used in place of the liquid crystal composition A in Examples 1 to 3 and stored in the same manner, and the specific resistance value (unit: Ω / cm ² ) was measured. Table 1 shows the results.

[Examples 7 and 8] Comparative storage example A liquid crystal composition A or a liquid crystal composition B was added to 100 ml of a heat-resistant screw-bottle (a) (manufactured by SCHOTT) made of borosilicate glass.
, And stored in the same manner as in Example 1, and the specific resistance value after storage (unit:
Ω / cm ² ). Table 1 shows the results.

[0041]

[Table 1]

[0042]

According to the liquid crystal material storage container of the present invention,
In a glass container, a fluorinated liquid crystal compound that could not prevent a decrease in specific resistance value can be stably stored. Further, the container is less likely to be damaged than a conventional glass container, and is therefore suitable as a container for transportation.

Claims (7)

[Claims] A container for storing a liquid crystal material, comprising: a container having at least two layers of a resin layer formed inside and a metal layer formed outside the resin layer in contact with the liquid crystal material. container. 2. A container having three layers: a resin layer formed on the inside in contact with a liquid crystal material, a metal layer formed on the outside of the resin layer, and a resin layer formed on the outside of the metal layer. The container for storing a liquid crystal material according to claim 1. 3. The container for storing a liquid crystal material according to claim 1, wherein the liquid crystal material is a liquid crystal compound comprising a compound containing fluorine, or a composition containing the liquid crystal compound. 4. The container for storing a liquid crystal material according to claim 3, wherein the compound containing fluorine is a compound represented by the following formula 1. Embedded image R ¹ -A-Ph-CF = CF-Ph-R ² Formula 1 wherein the symbols in the formula 1 have the following meanings. R ¹ : an alkyl group having 1 to 5 carbon atoms. A: A single bond or a trans-1,4-cyclohexylene group. R ^{2 represents a} fluorine atom, a chlorine atom, a cyano group, or an alkyl group having 1 to 5 carbon atoms, and in the case of an alkyl group, an oxygen atom, a trans double bond, or a triple bond between carbon-carbon bonds. May be included. Ph: 1,4-phenylene group. 5. A liquid crystal material stored in a first container having at least two layers of a resin layer formed inside and a metal layer formed outside the resin layer in contact with the liquid crystal material. A method for preserving a liquid crystal material, characterized in that: 6. A first container having at least two layers of a resin layer formed inside and a metal layer formed outside the resin layer in contact with a liquid crystal material, wherein the first container has an inner volume larger than that of the container. A method for preserving a liquid crystal material, wherein the liquid crystal material is placed in a second container described below. Second container: a container having at least two layers of a resin layer formed inside and a metal layer formed outside the resin layer in contact with the first container. 7. The method for preserving a liquid crystal material according to claim 6, wherein an oxygen absorbent and / or a water absorbent is inserted between the first container and the second container.