TW200404884A - Treatment method for reusing liquid crystal material - Google Patents

Abstract

A treatment method for recovery from a spent liquid crystal panel and reuse of a liquid crystal material having a purity and physical properties which qualify the material to be reused for liquid crystal panels. The method comprises the steps of (1) removing a liquid crystal material from a liquid crystal panel, (2) refining the removed liquid crystal, (3) determining the physical properties of the refined liquid crystal material, and (4) adjusting the physical properties of the liquid crystal material.

Description

200404884 (1) Description of the invention: (1) The technical field to which the invention belongs: The present invention relates to the reuse of defective panels discharged in the manufacturing process of liquid crystal panels, or liquid crystals used in liquid crystal display elements that have been discarded in the market. Processing method of liquid crystal material in panel. (2) Prior technology: Liquid crystal display elements are used in various applications as interfaces between humans and computers, and their production and market usage are increasing rapidly. Due to the recent increase in environmental awareness, research is being conducted on disposal methods or reuse methods that do not cause any environmental impact. However, the liquid crystal material contained in the liquid crystal panel is only a small amount of about 1 g even in a display of the size of a liquid crystal display element for a computer. In addition, the liquid crystal material is sandwiched between an organic film coated with an alignment film and the like on the inner surface of the glass, and is sealed with a sealing material such as an epoxy resin. Therefore, it is easy to take out without mixing impurities with good efficiency and reuse. It is difficult to develop reusable economical treatment methods. Among the methods for treating waste liquid crystal panels, a method for recycling and reusing liquid crystal materials has been proposed, and it is revealed that liquid crystals are washed out of the panel by using an organic solvent such as acetone or isopropyl alcohol, or are recovered by scraping the liquid crystals. The liquid crystal material is added and mixed in the recycling step to remove the low-molecular compound in the liquid crystal whose composition is changed due to the recycling, and the processing method for recycling the liquid crystal component for S liquid crystal recycling is performed. (Refer to Patent No. 5-200404884 Documents 1, 2, and 3). However, since the liquid crystal material obtained by the method disclosed in the aforementioned document is extremely low in purity, the physical properties of plutonium are abnormal due to recycling, and it is difficult to reuse the liquid crystal material as it is. It also discloses a method for recovering liquid crystal materials using a supercritical fluid (refer to Patent Document 4), a method for recovering using hot water (see Patent Document '5), and in order to reuse, it must have many physical properties. Adjustments, and these processing techniques have not been established. (Patent Document 1) · Japanese Patent Application Laid-Open No. 200 1 -3 05 5 0 1 (Page 3, paragraph numbers 0017 and 0018) (Patent Literature 2) Japanese Patent Application Laid-Open No. 200 1 -3 0 5 5 02 (No. 3 pages, paragraph numbers 0014 and 0015) (Patent Document 3) Japanese Patent Application Laid-Open No. 200 1 -3 3 7 3 0 5 (Page 3, paragraph numbers 0020 and 002 1) (Patent Document 4) Japanese Patent Laid-Open No. 2 0 0 2 -1 2 6 6 8 8 (Page 2, paragraph number 0 0 1 0) (Patent Document 5) JP 2002-1 6 62 5 9 (Page 2) (3) Summary of the Invention: Problem to be Solved The problem of the present invention is to provide a processing method for recycling a liquid crystal panel from a used liquid crystal panel with a purity and physical properties of reusable liquid crystal panels. A hand to solve the problem 跺 The inventors of the present application, etc. 'studied the results of the processing steps for taking out and reusing liquid crystal materials from a liquid crystal panel in detail to solve the above problems, and achieved the following inventions. That is, the present invention is a processing method for reusing liquid crystal materials, which is characterized by having 1) a step of removing the liquid crystal material from the liquid crystal panel, 2) a step of refining the removed liquid crystal material, and 3) measuring the refined liquid crystal. Steps of material physical properties and 4) Steps of adjusting the physical properties of the liquid crystal material. Only when the liquid crystal material is taken out from the liquid crystal panel, impurities or ionic impurities from the constituent elements of the liquid crystal panel are mixed. In the next step, a purification step that can remove the limit of these impurities must be taken as the second step. In the next step, it is necessary to compare the degree of refining before and after refining, and what components are removed by the treatment or refining that has been performed. In this case, since it is eventually reused as a liquid crystal panel, it is necessary to measure the physical properties of the liquid crystal material, which is the minimum necessary. By adjusting the liquid crystal properties obtained in this step and the minimum physical properties necessary for reuse, the recovered liquid crystal material can be reused. (IV) Embodiment: [Example] 1-200404884 The following describes the steps of the present invention in detail. (1) The step of taking out the liquid crystal material from the liquid crystal panel (0 cutting panel sealing the two glass substrates filled with the liquid crystal material are followed by the sealing material. When the panel is cut, it is cut on the inside of the sealing material. The open system of the two pieces of glass and the liquid crystal material sandwiched between them does not include a sealing material. The sealing material is usually made of epoxy resin or acrylate resin. 'It is important that the liquid crystal material does not include Resin shavings produced by sealing materials. The incorporation of resin materials into the liquid crystal material can be removed by filtering the liquid crystal material. However, since the liquid crystal material comes into contact with the resin shavings, the hardener and additives included in the resin are reduced to the liquid crystal. The purity of the liquid crystal extracted from the liquid crystal. Especially the ionic impurities are caused by poor display when the liquid crystal material is reused. It is necessary to avoid contact between the sealing material and the liquid crystal. (B) Take out the liquid crystal material from two sheets of glass (b-1) and use Organic solvent method Liquid crystal material can be washed out between two glass substrates by dissolving liquid crystal material with organic solvent In this way, from the obtained organic solvent solution of the liquid crystal material, the organic solvent is distilled off by using a method such as distillation to obtain a liquid crystal material. Generally, an organic film such as polyimide or Si02 is formed on the inner surface of two glass substrates. Inorganic film. When the organic solvent flows out as described above, it is required to mix the impurities from organic films such as 200404884 s and inorganic film to the minimum, and at the same time, the liquid crystal should be dissolved and washed out with as little organic solvent as possible. (Organic Solvents) #From the point of view of stomach, organic solvents are preferably hydrocarbon solvents with low polarity such as hexane and toluene. Alcohol solvents such as methanol, ethanol, isopropanol, or acetone, methyl ethyl ketone Other solvents have the disadvantage of high polarity, especially high solubility for ionic impurities. Therefore, when the recovery operation is performed with a highly polar solvent, the impurities are dissolved from the organic film or the inorganic film. Increasing the content of impurities is not good. Also, the alcohol system itself has a low specific resistance, and contains a lot of water or ionic impurities in the solvent. The resistance of the liquid crystal material taken out from the liquid crystal panel is not good as a solvent for extraction. Furthermore, the alcohol-based solvent is not highly soluble in the liquid crystal material. When an alcohol-based solvent is used, it may cause precipitation in the liquid crystal material. The situation is not good. Hydrocarbon-based solvents such as hexane and toluene are difficult to extract polar polymer components or oligomer components from organic and inorganic films or sealing materials. Moreover, the specific resistance of the solvent itself is also large. It is 1014Ω · (: γπ or so, which is very good. (B-2) It is useful to remove the liquid crystal material from two sheets of glass by blowing (blowing) the gas without using a solvent by blowing.) As a method of taking out the liquid crystal material 9-200404884 from two pieces of glass. Although air can be used as the blowing gas, in order to suppress the oxidative degradation of the liquid crystal material, it is better to use an inert gas such as nitrogen or argon. . As the blowing method, the following method can be used. A. A method of separating two glass substrates in advance and recovering the liquid crystal material by blowing gas on the liquid crystal material attached to each glass substrate. B. A method of blowing gas between two glass substrates. C. A method of efficiently taking out the liquid crystal material by peeling off two substrates while using the effect of concentrating the liquid crystals with the surface tension in the peeling direction of both substrates, and by blowing the gas. Method A is characterized in that the substrate is separated in advance and has a high blowing efficiency. However, since it is liable to cause oxidative degradation due to contact with air, it is preferable to blow an inert gas. Method B is short in contact with air and is not easy to cause oxidative degradation. Since the liquid crystal material sandwiched between the two substrates with a gap of # m must be blown out with the strength to overcome surface tension, the efficiency is poor. The method C is preferable because it can balance the viewpoint that oxidation degradation and recovery efficiency are not easily caused. The use of a non-reactive gas is particularly preferable. (Blowing method) In order to minimize the mixing limit of impurities from the organic film and the inorganic film that are in contact with the liquid crystal material and efficiently recover the liquid crystal material, the 200404884 inclined panel is collected in a single direction by blowing air Liquid crystal material. By blowing the gas in a straight line from the front end of the blowing nozzle, it is preferable to collect the liquid crystal material in a single direction like an airbrush. In the method of physically scraping by a doctor blade or the like, since it is impossible to avoid physically rubbing the organic film and the inorganic film, it is difficult to prevent the impurities from coming in from mixing in these films. (b-3) Method using centrifugal force A method using centrifugal force can be cited as a method without using a solvent. The two glass substrates are separated as described above, and the liquid crystal material is adhered to the glass substrate. Then, the glass substrate is set in a centrifugal separator, and the liquid crystal material is separated from the substrate by centrifugal force. It is preferable to set the glass substrate by separating the liquid crystal material from the glass substrate and effectively acting as a centrifugal force. It is also preferable to set up the reception of the liquid crystal material by efficiently recycling the separated liquid crystal material. The panel applicable by the recycling method of the present invention is not particularly limited if it is a liquid crystal panel. In the case of a slightly smaller panel, the amount of recycling is small, so it is better to apply to a panel with a diagonal of 140 mm or more. Panels above a diagonal of 200 mm are preferred. (2) The step of refining the taken out liquid crystal material (a) Refining by distillation as described below, 'The organic material formed from the loose, sealing material or glass substrate of the structural member of the liquid crystal panel as the sealing liquid crystal material The film and the non-200404884 organic film come from, and the low-molecular compounds and high-molecular compounds contained as impurities are mixed into the liquid crystal material, which must be removed from the liquid crystal material. In the case where the boiling point of the liquid crystal material is different from the boiling point of the impurities, it is more useful to remove the impurities by steaming, and it is more preferable to carry out the steaming at a relatively low pressure. (Molecular Distillation) Digestion of stomach molecules is performed under a local vacuum (less than 10-1 Pa), and a distillation method is performed by arranging a condenser within a short distance compared with the average free stroke of molecules evaporated from the heating surface. In this method, distillation can be performed without applying a high temperature to the liquid crystal material, and a liquid crystal material with a higher boiling point can also be refined. In this case, it is performed at a pressure of 10-1 to 1 (T2Pa), which is preferable because the temperature load on the liquid crystal material is reduced and the recovery rate of the low-molecular liquid crystal material is improved. Also, at a pressure slightly higher than the molecular distillation (more than 10 ^ Under Pa), short stroke distillation with a condenser at a distance slightly longer than the average free stroke of the molecule is also useful. Although this method is inferior to molecular distillation in terms of temperature load, the distillation efficiency is high and the throughput In most cases, it is better. (B) The liquid crystal material taken out from the liquid crystal panel by the purification of the adsorbent material contains ionic impurities. The ionic impurities are generated in addition to the deterioration of the liquid crystal material itself. As mentioned above, it is extracted from the sealing material used as the constituent member of the liquid crystal panel or the organic film and inorganic film on the glass substrate. Generally speaking, these ionic impurities are used to adsorb ionic compounds. The adsorption material that adsorbs the liquid crystal material is treated, and the ionic compound can be separated and removed from the liquid crystal material. Silicone, silica, alumina, zeolite, and ion exchange resins are better adsorption materials, and alumina, silica, and silica alumina are more preferred. These adsorbents can be mixed with different adsorbents to determine ionicity. As for the method for separating impurities, there are analysis methods such as ion chromatography, or the specific liquid crystal material can be evaluated by specific resistance, current chirp, and ion density measurement described later. The adsorbed liquid is used to treat the recovered liquid crystal material. Examples of methods include a method of using an adsorbent as column chromatography, a method of directly adding to a liquid crystal material, and a method of adding an adsorbent after dissolving in a solvent. In order to improve the adsorption efficiency, the liquid crystal material is dissolved in a solvent In the solution state, an adsorption material is added to the solution, and the method of improving the contact efficiency between the ionic impurities and the adsorption material by means of stirring is preferred. In order to completely remove the adsorption material after the liquid crystal material is refined, a membrane filter is used, etc. It is better to filter to separate and remove the adsorbent material. (3) Determine the physical properties of the refined liquid crystal material. The liquid crystal material that is taken out of the liquid crystal panel by the aforementioned method and obtained through the refining step has a composition different from that when it is injected into the liquid crystal panel. In addition, whether the recycled material is used for the same purpose as the taken out application If it is used for other purposes, it is necessary to grasp the characteristics of the material that is recovered. Although liquid crystal materials can be evaluated in terms of physical properties, including 200404884 properties, the following physical properties are measured. It is better to grasp this when it is used. When reusing the inch, the important physical properties of the liquid crystal material are the nematic liquid crystal phase of the liquid crystal material_ isophase phase transition temperature, refractive index anisotropy, permittivity anisotropy, spontaneous spacing and Specific resistance. The specific resistance 値 can be replaced by current 値, ionic density measurement, and retention measurement. (Nematic liquid crystal phase-isotropic phase transition temperature) When a liquid crystal material for a liquid crystal panel is used, liquid crystal is used. Under the upper limit of the operating temperature of the panel, since the nematic liquid crystal phase must be present, the nematic liquid crystal phase of the recovered liquid crystal material-isotropic phase transition Degree (Tni) of the measured piece goods is important. The measurement of Tni can be performed by a conventional method. That is, there are a method of visual measurement by a polarizing microscope and a method of DCS measurement. In the aforementioned refining step, since there is a possibility that the low molecular weight compounds in the liquid crystal material are partially removed by distillation, and the high molecular weight compounds are removed by non-partial distillation, in the case of refining by distillation, Tni The determination is important. (Refractive Index Anisotropy) When a liquid crystal material is used as a liquid crystal panel, the product of the distance between the two substrates constituting the panel and the refractive index anisotropy (△ η) of the liquid crystal material used is because For the physical properties necessary for the optical design of a liquid crystal panel, it is important to determine the Δη that is recovered. The measurement system can use the method commonly used in 200404884. That is, a method using an Abbe refractometer and a method using a micro refractometer can be cited. (Dielectric constant anisotropy) In the case of using a liquid crystal material as a liquid crystal panel, since the liquid crystal material is driven by a driving voltage, is it possible to obtain sufficient physical properties necessary for electro-optical design with sufficient contrast? The measurement of dielectric anisotropy (Δε) is important. In the purification step using the aforementioned adsorbent, it is possible to remove a part of the highly polar compounds in the liquid crystal material and to remove it. When an adsorbent is used in the purification step, the measurement of Δε is particularly important. In addition, the measurement of Δ ε can be performed by injecting into a standard liquid crystal panel and measuring the voltage-transmittance characteristics, and confirming the critical chirp voltage or saturation voltage. (Spontaneous Pitch) Usually, an optically active compound required for developing a spiral structure is added to a liquid crystal material used in a liquid crystal panel, and a spontaneous pitch (ρ; β rn) is given to the liquid crystal material. The smaller the spontaneous pitch is, on the one hand, misalignment occurs, and on the other hand, it is an indispensable physical property because it cannot satisfy the designed electro-optical characteristics such as contrast or response speed. The measurement system can be measured using a wedge-shaped element. In the case of the refining method by the aforementioned distillation or the refining method by adsorption, on the one hand, a part of the high molecular weight optically active compound is lost from the distillate, and on the other hand, it is selectively adsorbed on the adsorbent material. Add 200404884. The added amount is less than the original amount, so it is important to determine the spontaneous spacing of the recovered liquid crystal material. (Measurement of specific resistance, current chirp, ion density, and voltage retention rate) Of course, it is needless to say that when driven by an active element, a high liquid crystal material ratio is also required when driven by a passive element. Resistance 値. However, the recovered liquid crystal material contains the above-mentioned ionic impurities, and the specific resistance is much lower than that which has been injected into the liquid crystal panel, and becomes about i n OO. The effects due to ionic impurities can be evaluated by measuring the current density, ion density, and voltage holding ratio in addition to the specific resistance measurement. (4) Step of adjusting the physical properties of the liquid crystal material The physical properties of the liquid crystal material used for the liquid crystal panel can be adjusted by mixing a liquid crystal compound as the constituent component. (Adjustment of nematic liquid crystal phase-isotropic phase transition temperature (Tni)) In the refining step, it is useful to re-add a liquid crystal compound for adjustment in the case where the original Tni is changed by distillation or an adsorbent. The T n i system is approximately the same as the addition rule for the mixing of compounds and compositions. The proportion of the added material can be calculated by the following formula. General formula (A) 200404884 X (%)

Tc-Tr Tc-Tx

xlOO Tni (° C) of desired liquid crystal material: Tr Tni (° C) of compound added: Tx Tni (° C) ·· Tc of refined liquid crystal material

Composition ratio (%) of added compound: X For example, Tni = 90 ° C of desired liquid crystal material, Tni of refined liquid crystal material = 85 ° C, Tni of added liquid crystal compound (p) In the case of = 77 ° C, the ratio of the compound added can be calculated by substituting each of them in the general formula (a). That is, if the liquid crystal compound (P) is added in the ratio of the refined liquid crystal material: 94.6% and the liquid crystal compound (P): 5.4%, a liquid crystal material with T n i = 90 ° C can be obtained. The difference between calculated 値 and real 値 obtained by this method is usually within 1 ~ 2 ° C. When the aforementioned mixing is actually performed, a liquid crystal material of 9 0.4 ° C is obtained. In ordinary purification, due to the effects of adsorption and the like, most of the compounds with a large molecular weight and long molecular weight are smaller than the original content. Therefore, in order to adjust Tni, a 3-ring or 4-ring compound represented by the general formula (I) is preferred.

R] —A—7-} — B

1 7- 200404884 (In the general formula, R1 and R2 each independently represent an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, and 2 to 16 which can be replaced by fluorine. Alkenyl group of 3 carbon atoms or alkenyloxy group of 3 to 16 carbon atoms; A, B and C each independently represent 1,4-phenylene, 2- or 3-fluoro-1,4 -Phenylene, 2,3-phenyl-1,4-phenylene, 3,5-difluoro-1,4-phenylene, 2- or 3-chloro-1,4-phenylene, 2,3-dichloro-1,4-phenylene, 3,5-dichloro-1,4-phenylene, 2-methyl-1,4-phenylene, 3-methyl-1, 4-phenylene, naphthalene-2,6-diyl, phenanthrene-2,7-diyl, fluorene-2,7-diyl, trans-1,4-cyclohexenyl, 1,2,3, 4-tetrahydronaphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, trans-1,3-dioxane-2,5-diyl, pyridine-2,5-diyl, Pyrimidine-2,5-diyl, pyridine-2,5-diyl, or pyridyl-2,5-diyl, these functional groups can also be replaced by 1 ~ 3 fluorine atoms, m represents 1 Or 2, Z1 and Z2 each independently represent a single bond,-(3112 (: 112-,-(<: 112) 4-, -OCH2-, -CH20-, -COO-, -CH = CH-, -CF = CF-, -CH = NN = CH-, or- CeC-. However, when m is 2, the two Z2 and C may be independently the same or different.) Among these liquid crystal compounds, in order not to affect other characteristics easily, they can be efficiently used. The adjustment is preferably a compound with a Tni of 120 ° C ~ 300 ° C. Among the compounds with a lower Tni than 120 ° C, the amount of addition must be increased for adjustment. Because on the one hand, it affects other characteristics, one On the other hand, the solubility is insufficient and the possibility of precipitation is not good. In addition, in compounds higher than 300 ° C, the amount of addition is reduced, and the adjustment error is large, which is disadvantageous for the effective adjustment of 200404884. According to the general formula ( Ϊ) For compounds represented by A), A, B, and C are preferably 1,4-phenylene or trans-1,4-cyclohexenyl. Furthermore, a and B are both trans-1,4-cyclo Hexenyl bicyclohexane compounds are preferred because Δη is small, Δ ε is small, and Tni is high, because Tni can be adjusted to reduce the effect of Δη or Δ ε of liquid crystal materials. Atomic number alkyl groups are preferred. Ζι and Z2 are preferably single bonds, -CH2CH2- or -C00_. Single bonds are Excellent chemical stability, it is not easy to damage the stability of the liquid crystal material due to the addition. Also, _ C 〇0 _ is because of high solubility, can increase the amount of addition, at the same time because it is not easy to cause precipitation. X adjustment 'can be the same The liquid crystal composition having Tni not only necessary for adjustment of the liquid crystal compound is adjusted by addition. (Adjustment of refractive index anisotropy (Δ η)) The Δη of the liquid crystal material after purification only changes the contribution component of the compound lost by the purification. Similar to the adjustment of Tni, it can be adjusted by adding a liquid crystal compound according to the following formula (B) to adjust to the desired formula (B): ¥ (%) =

Nc-Nr τ; —— χίοο

Nc ~ Ny 200404884 An: Nr desired liquid crystal material: Δη: Ny refined liquid crystal material Δη: Nc composition ratio of compound added (%): γ In order to efficiently add a small amount For adjustment, compounds with large Δη are useful. The range of the compound to be added is preferably 0 ·; [5 to 0.30] is preferable. These compounds are preferably compounds having a biphenyl skeleton or compounds having a diphenylacetylene skeleton. Also, in the slight adjustment of Δη, a compound with a smaller ηη is useful. As a preferable Δη, a compound having a range of 0.03 to 0.07 is mentioned. Among compounds having such Δη, compounds having a bicyclohexane skeleton are preferred because Δη is small and Tui is high. Similarly to the adjustment of Tni, in the adjustment of the An of the refined liquid crystal material, the liquid crystal composition having Tni not only necessary for the adjustment of the liquid crystal compound can also be adjusted by addition. (Adjustment of dielectric anisotropy (△ ε)) △ 6 compounds are one of the compounds that are easily lost due to purification. The Δ ε of the liquid crystal material after purification only changes the contribution component of the compound lost by the purification. Similarly to the adjustment of Tni, it can be adjusted to a desired Δε by adding a liquid crystal compound in accordance with the following general formula (c). -20- 200404884 General formula (c) Z (%)-

Ec-Er Ec-Ez

xlOO

△ ε of desired liquid crystal material: Er △ of added compound: ε: Ez △ ε of refined liquid crystal material: E c Composition ratio of compound added (%: Z For efficient adjustment with small addition It is useful to use a compound with a large Δ ε. For the range of Δ ε of the compound to be added, Δ ε is preferably 5 to 40. These compounds are compounds having a cyano terminal group or fluorine A terminal compound is preferred. A compound having a cyano terminal group can be adjusted with a small amount of addition because of a large Δ ε. In addition, a compound having a fluorine terminal group is small Δ ε and is suitable for slightly adjusting Δ ε Compounds with a fluorine terminal group are not easily contaminated due to ionic substances, etc. 'Because it is not easy to improve the specific resistance 値 improved by purification, it is suitable as a liquid crystal material for adjustment. In particular, it has 3, 4, 5-trifluoro Compounds of benzene are particularly suitable. Examples of suitable compounds used in the present invention include compounds represented by the general formula (II). (Ii) 200404884

(In the general formula, R3 represents an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, or an alkenyl group having 3 to 16 atoms that can be replaced by fluorine. Diluted oxy group of bond; D and E are individually unique, i.e. 4-phenylene, 2- or 3-fluoro-1,4-phenylene, 2,3- 4-phenylene, 3 , 5-Difluoro-1,4-phenylene, 2- or 3-chloro-1,4-phenylene, 2,3-dichloro-1,4-phenylene, 3,5-dichloro -l, 4-phenylene, 2-methyl-I, 4-phenylene, 3-methyl-1,4-phenylene, naphthalene-2,6-diyl, phenanthrene-2,7- Diyl, fluorene-2,7-diyl, trans-1,4-cyclohexenyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, decahydronaphthalene-2,6- Dibasic, trans-1,3-

Dioxane-2,5-diyl, pyridine-2,5-diyl, pyrimidine-2,5-diyl, pyridin-2,5-diyl, or pyridyl-2,5-diyl, These functional groups may be further substituted by 1 to 3 fluorine atoms, η represents 0, 1 or 2, and Z3 and Z4 each independently represent a single bond, -CH2CH2-,-(ch2) 4-,-. ch2-, -CH20-, -COO-, -CH ^ CH-, -CF =: CF-, -CH = NN = CH-, or -C Triple C-. Y represents a cyano group, a fluorine atom, a chlorine atom, a trifluoromethoxy group, a trifluoromethyl group, a difluoromethoxy group, a hydrogen atom, or a 3,3,3-trifluoroethoxy group; X1 and X2 represent a hydrogen atom, A fluorine atom or a chlorine atom. However, when η is 2, the two Z3 and E may be independently the same or different. In the compound represented by the general formula (II), D and E are preferably 1,4-phenylene or trans-1,4-cyclohexenyl. Furthermore, D and E are both anti-1,4--22-200404884. The cyclohexyl compound is a cyclohexyl compound. Because Δε is small and Tni is high, it can affect the Δη or Tni of the liquid crystal material. It is better to adjust Δ ε small. R3 is preferably an alkyl group having 1 to 5 carbon atoms. Z3 and Z4 are preferably a single bond, TT- or -COO-. Single-bond systems are not easy to use due to their excellent chemical stability. · The stability of liquid crystal materials is impaired by addition. Moreover, -C 〇 0-is preferable because it has a high solubility and can be added in a large amount. X1 and X2 are preferably at least one of fluorine, and more preferably a compound of fluorine. Υ is preferably fluorine or CN. In the case of attaching importance to chemical stability, fluorine is preferable. In the case of large adjustment Δ ε, CN is preferable. Specifically, a compound having 3,4,5-trifluorophenyl or a compound having 4-cyano-3,5-difluorophenyl is preferred. In addition, during the adjustment, a liquid crystal composition having Δε necessary for adjustment of not only the liquid crystal compound can also be adjusted by addition. (Simultaneous adjustment of a plurality of physical properties) When the nematic liquid crystal phase-isotropic phase transition temperature (Tni), refractive index anisotropy (△ n), and dielectric anisotropy (△ ε) are adjusted at the same time, By calculating X, γ, and 2; which satisfy the three general formulas represented by the general formula (c), general formula (D), and general formula (E) at the same time, the ratio of the three added materials can be obtained. General formula (D): -23- 200404884 (7x-Tc) X + (Ty-Tc) Y + (Tz ~ Tc) Z = {Tr ^ 7c) x 100 General formula (E): (Nx-Nc) X + (Ny-Nc) Y + (Nz-Nc) Z = (Nr-Nc) x 100 General formula (F): (Ex-Ec) X + (Ey-Ec) Y + (Ez-Ec) Z = ( Er ~ Ec) x 100 Tni (t) of the desired liquid crystal material: Tr An of the desired liquid crystal material: Nr △ of the desired liquid crystal material ε: E r Tni of the refined liquid crystal material (° C): △ of liquid crystal material after Tc purification: △ of liquid crystal material after NC purification ε: E c The composition ratio of compound added for adjusting Tni (%: χ of compound Tni (° C): Tx added Δη of the compound: △ ε of the compound added ε: Ex For adjusting the composition ratio (%) of the compound added by Δ η: T Tni (° C) of the compound: Δ of the compound added by Ty: η: N y △ ε of added compound: Ey -24- 200404884 Used to adjust the composition ratio (%) of △ ε added compound: Z ^ Tni of compound (° C): Tz Δη of added compound: Νζ added △ ε of the compound: Εζ # The compound used for adjustment is added, but each one must be used as a physical property for the purpose, and it can also be performed several times. At this time, in order to improve the composition's low-temperature storage, other The compound is preferred. In the case where the intended physical properties cannot be obtained at one time, the aforementioned measurement steps and adjustment steps can be repeated. For the purpose of improving the preservation property at low temperature, if the amount of the same material is to be reduced The number of components can also be increased in the same way. (Spontaneous spacing) It can be said to be one of the compounds that are easy to lose due to purification. Because of the loss of the compound, the spontaneous spacing (p) 0 of the refined liquid crystal material becomes larger. The spontaneous pitch of the liquid crystal material (spiral elongation) has a great influence on the critical voltage of the liquid crystal display element or the stability of the alignment. The spontaneous pitch of the liquid crystal material is, for example, according to the general formula (G): HTP = l / ( px〇MC) (In the general formula, C represents the addition amount (% by mass) of the optically active compound, and p represents the spontaneous distance (// m).) -25-200404884 helical twisting power: ΗΤΡ (1 / // m) is inversely proportional to the product of the concentration of the compound of the palm (mass%) of the added. In order to adjust with a small amount of addition, although the torsional compound with large torsional power is effective, but the torsional compound with too large torsional power is difficult to fine-tune. Therefore, the torsional power of the used with palm compound is 3 to 30 ) Is better. The torsional power is obtained from the reciprocal of the spontaneous pitch when a 1% by mass para compound is added to the liquid crystal material. This system varies depending on the matrix to be added, so it is better to calculate the torsional power by adding 1% by mass to the refined liquid crystal material to be adjusted for use. As a preferable palm compound, in addition to a cholesterol derivative such as cholesterol nonanoate, the following compounds may be mentioned. COO—COOCH-R '(ΙΙΙ · 1)' COO——COO—-CH2—CH-R (III-2) (III · 3) (111-4)

氺 COO— CH I ch3-< 0 > 〇 〇 一 CH — R I CH3 200404884

(ΙΙΙ · 5) (111 * 6) (In each formula, R and R represent an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, and 2 to 16 carbon atoms. Alkenyl group or alkenyloxy group having 3 to 16 carbon atoms.) According to the processing method of the present invention, a liquid crystal composition having the same physical properties as the original liquid crystal material before recovery can be recovered. In addition, a liquid crystal composition having properties different from those of the conventional liquid crystal composition can be recovered. That is, since the liquid crystal display is designed to have very delicate characteristics, the original liquid crystal composition cannot be completely recovered under any circumstances. It is also difficult to return to the same cycle number dependence, temperature dependence, and response of the critical voltage. This difficulty is largely dependent on the extent to which liquid crystal materials are contaminated for recycling. In order to remove contamination, it is necessary to perform a refining operation at any step, which is long and long, and causes a large change in characteristics from the original liquid crystal composition. In these cases, it is not necessary to restore the liquid crystal composition with the original phase, so it is better to adjust for liquid crystal materials with different required characteristics for reusability. [Examples] In the following, although examples are given to further describe the present invention, the present invention -27-200404884 is not limited by these examples. A liquid crystal material (A) was produced by a fixing method. The composition and physical properties of the liquid crystal material (A) will be described below.

-28- 200404884

c5Hh- < > -ch2ch2 ·

Factory 5% 10%

10%

10% 10% 10%

Tn i =: 9 〇. C Δ n = 0. 0 9 5

-29_ 200404884 Α ε 2 7 · 5 ρ = 8 5 // m Specific resistance = 5 · 8χ 1012 Ω · cm Make 200 pieces with a display area of 20 cm square, and the distance between two glass substrates is 1 〇 # m of 90 . A TN liquid crystal display is filled with a liquid crystal material (a). The obtained liquid crystal display had a Vth of 1.69 V and a voltage holding ratio of 98%. The display was placed in a thermostatic bath at 80 C for 500 hours. (Step of taking out the liquid crystal material from the liquid crystal panel) Cutting is performed on the inside of the sheet following the two substrates to obtain a liquid crystal material sandwiched between the two glass substrates. Be careful not to mix in impurities from the sheet or the alignment film, and slowly peel off the two substrates. Nitrogen gas is blown onto the liquid crystal material attached to the substrate, and liquid crystal is collected in the liquid crystal storage tank A at the same time. If the above liquid crystals have not been collected, the liquid crystal is further collected in the liquid crystal storage tank B by washing the n-hexane and flowing down the substrate. This step was performed for 200 liquid crystal displays, and the n-hexane in the liquid crystal storage tank B was distilled off by an evaporator to obtain a recovered liquid crystal material. The recovered liquid crystal material from which the solvent has been distilled off and the liquid crystal material recovered from the liquid crystal storage tank A are combined to obtain 6 g of recovered liquid crystal material (R 1) (a step of refining the liquid crystal material taken out). Gas chromatograms of the liquid crystal material and the liquid crystal material recovered from the liquid crystal storage tank b. This result is that the peak content of the liquid crystal material recovered from the liquid crystal storage tank a is less than 1% in the liquid crystal material recovered from the liquid crystal 200404884 bedding tank B, so the liquid crystal material recovered from the liquid crystal storage tank 8 is combined. And the liquid crystal material recovered from the liquid crystal storage tank A is subjected to the following refining steps (in the case of more than ％), the refining steps are provided separately. The specific resistance of the obtained liquid crystal material before refining was 6.8 x ιιιι ^^ r τυλ η square, ίο Pa vacuum degree The molecular weight distillation was used to refine the material taken out to obtain a 5 · 2 g recovery liquid. The crystal material (R2) was quenched and recovered to recover the liquid crystal material (R2) in n-hexane, washed with ion-exchanged water, and then the liquid crystal material was adsorbed and refined by using 0.1% sand glue. The same recipe (R3) was used as before. The hexane was distilled off to obtain a recovered liquid crystal material (the step of determining the physical properties of the liquid crystal material refined by the method). The spontaneous pitch of the recovered liquid crystal was measured. Tni, Tni of the material (R3),

A A P 8 8〇C 0.094 = 7.0 9〇 / zm Resistance = 4.6x 10

Q understands that the specific electric capacity is improved by refining the steps and that the specific resistance 200404884 which is used as an active display is sufficiently high. However, it was learned that T n i decreased by 2 ° C, Δη decreased by 0.001, Δε decreased by 0.5, and ρ extended by 5 // m. In order to reuse the liquid crystal material, although the original characteristics may not necessarily be restored, it is attempted to reproduce the characteristics of the liquid crystal material (A) common to this laboratory. As Tni decreases, add the general formula (A-1)

(Tni = 168 ° C, Δη ^ Ο.Οθ., Λε ^ Ο · 8); As Δe becomes smaller, the general formula (A-2) is added

(Tni = 94 ° C, △ nsO.OQ, the indicated compound. In addition, due to the spontaneous spacing elongation, in the addition of (111-1), R is C 6 Η, 3 Ο-, R 'is C 6 Η! 3 of Compound, with the general formula (A-8) C6H13.

The compound represented by CO〇CH — C6H13 (A-3) ch3 was used as the palmar compound. The amount of the compound represented by the general formula (A-1) is X%, and the amount of the compound represented by the general formula 200404884 (Ad) is Z%, and the above general formula (D) and general formula (F) are used. Calculate the added liquid crystal material as Tni = 90 ° C, △ η 0.095 and Δ ε 7.5. Substituting this element into the general formula (D) leads to the following general formula. (168-88) χ + (94-88) Z = (90-88) χ 100 80Χ + 6Z = 200

Next, 値 is introduced into the general formula (F) to derive the following general formula. (0.8-7) X + (12-7) Z- (7.5-7) x 100 -6 · 2 × + 5Z = 50 Solve the simultaneous equations and calculate X 1 · 6% and Υ = 1 1 · 8%. The adjusted Δη at this time can be obtained by substituting 値 η in the general formula (E). Δη- (0.094x 0.866) + (0.090x 0.016) + (0.095x 0.118) = 0.094 The amount of the compound represented by the general formula (A-3) used for spontaneous pitch adjustment is determined by the following method. When 1% by mass of the compound represented by the general formula (A-3) was added to the purified object, and the spiral twist power (HTP) of the compound represented by the general formula (A-3) in the liquid crystal material was measured, This gives HTP = 10.0. From the general formula (G), the concentration of the palmar compound to be added was determined from 1 / 85-l / 90 = 10AC: Ac, and Δ C = 0 · 0 1%. Based on the above calculation, the 86.6% refined liquid crystal material, i-33- 200404884% general formula (A-1) and 1 1 · 8% general formula (a-2), are mixed at 9 9 · 9 9% 0.01% of the general formula (Ad) was mixed in this mixture to adjust physical properties. When measuring the physical properties of the liquid crystal composition, T ni = 8 9.7 t :, △ η = 〇. 09, 5, ε 7.6, ρ = 8 4 // m, which is very consistent with the calculation of 値, and the desired result is obtained. Recyclable liquid crystal material. The obtained recovered liquid crystal material was vacuum-injected into an original TN liquid crystal display to measure characteristics.

The Vth is 1.67V and the voltage retention rate is 98%. The characteristics are roughly the same as those of the LCD monitor before use. In the scope of the present specification and patent application, all% indicates mass%. [Effects of the Invention] Through the processing steps of the present invention, it is possible to recycle the reusable liquid crystal material from a conventionally used liquid crystal panel which is considered difficult. (V) Simple illustration of the schema: None.

Claims (1)

200404884 Scope of patent application: 1. A processing method for reusing liquid crystal materials, which is characterized by i) a step of taking out the liquid crystal material from the liquid crystal panel, 2) a step of refining the liquid crystal material taken out, and 3) measuring (4) a step of refining the physical properties of the liquid crystal material, and 4) a step of adjusting the physical properties of the liquid crystal material. 2 · If the applicant for the scope of application of the first scope of the liquid crystal material for recycling In the method, the step of taking out the liquid crystal material from the liquid crystal panel is a step of taking out the liquid crystal material from the panel by dissolving the liquid crystal material with a hydrocarbon-based organic solvent, and then removing the organic solvent by distillation. . 3. The processing method for reusing liquid crystal material as described in the first item of the patent application scope, wherein the step of taking out the liquid crystal material from the liquid crystal panel is a step of taking out the liquid crystal material from the panel by blowing a gas. 4. The processing method for reusing liquid crystal materials as described in the first patent application scope, wherein the step of refining the liquid crystal materials is molecular distillation. 5. The processing method for reusing liquid crystal materials as described in the scope of patent application No. 4, wherein the degree of decompression of molecular distillation is lC ^ Pa ~ l (T2Pa. 6. The treatment method for reusing liquid crystal materials according to item 1 of the scope of patent application, wherein the step of refining the liquid crystal material is to use at least one selected from the group consisting of alumina, silicone, silica aluminas, zeolites, and ion exchange resins. Group steps. 7. The processing method for reusing liquid crystal materials according to item 1 of the scope of patent application, wherein the step of measuring the physical properties of the liquid crystal material is to measure the nematic liquid crystal phase-isophase phase transition temperature and refraction of at least one liquid crystal material. Steps of different rate directivity, permittivity directivity, spontaneous spacing and specific resistance. 1 35- 200404884 8 · $ [] $ Stomach's patent scope of the first item of the processing method for the reuse of liquid crystal materials '/ Go' # φAdjusting the properties of liquid crystal materials 步骤 The step is to add nematic liquid crystal clear mesh-etc. The step of the phase transition temperature of the liquid crystal compound or liquid crystal composition in the direction of i 2 0 3 to 3 0 0. 9. The treatment method for reusing liquid crystal materials according to item δ of the scope of patent application, wherein the nematic liquid crystal phase-isotropic phase transition temperature is 12 (rc ~ 30 (rc 2 ') Liquid crystal compound or liquid crystal composition with bicyclohexylbenzene skeleton. 10. For example, the treatment method for reusing liquid crystal materials according to item 丨 of the application scope, wherein the step of adjusting the physical properties of the liquid crystal material is to add the dielectric rate in different directions A liquid crystal compound or a liquid crystal composition having a property of 5 to 40. 1 1 · A method for reusing a liquid crystal material as described in item 10 of the scope of patent application, wherein the dielectric anisotropy is 5 to 4 0 A liquid crystal compound or a liquid crystal composition is a liquid crystal compound or a liquid crystal composition having a structure of 3,4,5-triphenylbenzene. 1 2 · As a method for reusing liquid crystal materials in the first item of the scope of patent application, The step of adjusting the physical properties of the liquid crystal material is a step of adding a liquid crystal compound or a liquid crystal composition having a refractive index anisotropy of 0 · 0 3 to 0 · 0 7. Again Processing method using liquid crystal material, wherein the liquid crystal compound or liquid crystal composition with refractive index anisotropy of 0.03 ~ 07 is a liquid crystal compound or liquid crystal composition having a bicyclohexane skeleton. 1 4 · If applied The treatment method for reusing liquid crystal materials in item 1 of the patent scope -36-200404884 method, wherein the step of adjusting the physical properties of the liquid crystal material is to add a liquid crystal compound having a refractive index anisotropy of 0 · 1 5 to 0 · 30 or Steps of liquid crystal composition. 15 · The processing method for reusing liquid crystal materials as described in item 14 of the patent application scope, wherein the liquid crystal compound or liquid crystal composition of the refractive index anisotropy is 0.1 to 0.3. The material is a liquid crystal compound or a liquid crystal composition having a biphenyl skeleton. 1 6 · The method for reusing liquid crystal materials as described in the first item of the patent application, wherein the step of adjusting the physical properties of the liquid crystal material is to add optical activity Substance steps. 1 7 · As for the treatment method for reusing liquid crystal material in item 1 of the scope of patent application, in which the liquid crystal panel has a diagonal of more than 140 mm. 1. The treatment method for reusing liquid crystal materials according to item 1 of the scope of interest, wherein the physical properties of the liquid crystal material constituting the liquid crystal panel before recycling are the same as those of the liquid crystal material after recycling. 1 9 The treatment method for reusing liquid crystal material in item 1, wherein the physical properties of the liquid crystal material constituting the liquid crystal panel before recycling are different from the physical properties of the liquid crystal material after recycling. 2 0 A processing method for reusing liquid crystal materials, wherein the liquid crystal material is a liquid crystal material for an active matrix. 200404884 柒. Designated representative map: (1) The designated representative map in this case is: (). (2) Brief description of the representative symbols of the components in this representative diagram: If J, if there is a chemical formula in this case, please disclose the chemical formula that best shows the characteristics of the invention: