CN111892530B - Light stabilizer, and preparation method and application thereof - Google Patents
Light stabilizer, and preparation method and application thereof Download PDFInfo
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- CN111892530B CN111892530B CN201910366858.2A CN201910366858A CN111892530B CN 111892530 B CN111892530 B CN 111892530B CN 201910366858 A CN201910366858 A CN 201910366858A CN 111892530 B CN111892530 B CN 111892530B
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- liquid crystal
- esterification reaction
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D211/00—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings
- C07D211/92—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with a hetero atom directly attached to the ring nitrogen atom
- C07D211/94—Oxygen atom, e.g. piperidine N-oxide
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K19/00—Liquid crystal materials
- C09K19/52—Liquid crystal materials characterised by components which are not liquid crystals, e.g. additives with special physical aspect: solvents, solid particles
- C09K19/58—Dopants or charge transfer agents
- C09K19/586—Optically active dopants; chiral dopants
- C09K19/588—Heterocyclic compounds
Abstract
The invention belongs to the field of light stabilizers, and particularly relates to a light stabilizer, a preparation method and application thereof, wherein the light stabilizer has a structure shown in a general formula I:
Description
Technical Field
The invention belongs to the field of light stabilizers, and particularly relates to a light stabilizer and a preparation method and application thereof.
Background
Liquid crystal displays (liquid crystal displays) are displays utilizing photoelectric change of liquid crystal, and have advantages of small size, light weight, low power consumption, good display quality, and the like, so that they have become the mainstream of flat panel displays in recent years. Representative liquid crystal display modes include a Twisted Nematic (TN) mode, a Super Twisted Nematic (STN) mode, an in-plane switching (IPS) mode, a Fringe Field Switching (FFS) mode, and a Vertical Alignment (VA) mode. However, the liquid crystal medium used for the display element of the active matrix addressing mode such as the VA mode has disadvantages such as residual image water, relatively slow response time, relatively high driving voltage, and the like.
The stabilizer is an additive of a high molecular product, can shield or absorb the energy of ultraviolet rays, quenches singlet oxygen groups, decomposes peroxide into inactive substances and the like, and is capable of eliminating or slowing down the possibility of photochemical reaction and preventing or delaying the process of photoaging under the radiation of light, thereby achieving the purpose of prolonging the service life of the high molecular product.
In recent years there have been successive reports of photoinitiators for liquid-crystalline media, however, for many practical applications of liquid-crystalline displays, the known liquid-crystalline media are not sufficiently stable, in particular their stability to UV and even to conventional backlight radiation leads to impairment in particular of the electrical properties, for example, a significant increase in the electrical conductivity, etc. According to the disclosure therein, liquid crystal mixtures using these types of stabilizers have their voltage holding ratio reduced after exposure to light, and moreover color yellowing and the like often occur.
Disclosure of Invention
The first object of the present invention is to provide a light stabilizer having good heat resistance, mutual solubility, stability and low rotational viscosity, and a liquid crystal composition containing the light stabilizer compound has a high specific resistance value, a low threshold voltage, good stability against degradation by heat and UV exposure and a stable high VHR, and has important application values.
The compound provided by the invention has the following structure (shown in a general formula I):
wherein, in the general formula I, the R2Denotes H, F, an alkyl or alkoxy group having 1 to 12 carbon atoms, or an alkanyl or alkoxyalkenyl group having 2 to 12 carbon atoms, wherein the alkyl or alkoxy groupAlkoxy and alkanyl or alkoxyalkenyl in which H may be substituted by F, one or more non-adjacent-CH2-may each independently be substituted by-O-, but with the proviso that the O atoms are not directly attached to each other;
z is1、Z2、Z3Independently of one another- (CH)2) One of- (O-), - (C ═ O) -, or- (C ═ C) -, but does not simultaneously represent-O-;
m and n are the same or different, and m + n is more than or equal to 0 and less than or equal to 12;
0≤K≤12；
preferably, in formula I, R is2Denotes H, F, alkyl or alkoxy of 1 to 6 carbon atoms or alkanyl or alkoxyalkenyl having 2 to 6 carbon atoms in which H may be substituted by F, one or more non-adjacent-CH2-may each independently be substituted by-O-, but with the proviso that the O atoms are not directly attached to each other;
z is1、Z2Independently of one another- (CH)2)-；
Z is3Is represented by- (CH)2) -, -O-or- (C ═ C) -, the O atoms not being directly linked to each other;
m and n are the same or different, and m + n is more than or equal to 0 and less than or equal to 12;
0≤K≤6；
further preferably, in formula I, K ═ 0, the structure of which is shown in formula II:
as a preferred technical scheme of the invention, the compound is selected from one or more of the following compounds:
more preferably, when K is 0, the compound is effective, and has the structure:
more preferably, the compound is selected from one or more of the following structures:
the second object of the present invention is to provide a process for preparing the above compound, which comprises the following steps:
the method comprises the following specific steps: to be provided with
And
as raw materials, the raw materials are subjected to esterification reaction to obtain
Wherein R in the compound involved in each step2、m、n、k、Z1、Z2、Z3With R in the resulting compound product2、m、n、k、Z1、Z2、Z3The groups represented correspond (above).
The invention further provides that in the esterification reaction,
the feeding molar ratio of (2.0-4.0): 1; preferably the molar ratio is (2.0-3.0): 1;
the temperature of the esterification reaction is between-30 ℃ and 50 ℃; the reaction temperature is preferably-10 ℃ to 30 ℃;
the esterification reaction time is 4-12 h; preferably, the reaction time is 6-10 h;
the esterification reaction needs a catalyst, and the catalyst is one or more of dicyclohexylcarbodiimide, concentrated sulfuric acid, p-toluenesulfonic acid and the like; preferably the catalyst is dicyclohexylcarbodiimide.
As described above
Can be synthesized by publicly available commercial methods or by methods known per se in the literature.
The method of the invention, if necessary, involves conventional post-treatment, such as: extracting with dichloromethane, ethyl acetate or toluene, separating, washing with water, drying, evaporating with vacuum rotary evaporator, and purifying the obtained product by reduced pressure distillation or recrystallization and/or chromatographic separation, without any special limitation.
The compound of the invention can be stably and efficiently obtained by the preparation method.
A third object of the invention is to protect compositions containing said compounds. The compounds of the invention comprise, based on the overall mixture: 1ppm to 1000ppm, preferably 1ppm to 800ppm, and more preferably 1ppm to 500 ppm.
The fourth object of the present invention is to protect the use of said compounds and compositions containing said compounds in the field of liquid crystal displays, preferably in liquid crystal display devices. The liquid crystal display device includes, but is not limited to, TN, ADS, VA, PSVA, FFS or IPS liquid crystal display.
The compound of the invention has the following beneficial effects:
the compound has good rotational viscosity and liquid crystal intersolubility, excellent low-temperature working effect, excellent thermal stability, chemical stability, optical stability, mechanics and other performances, and the liquid crystal composition containing the compound has high specific resistance, low threshold voltage, high response speed, good stability and stable high VHR (very high frequency response) especially for thermal and UV (ultraviolet) exposed degradation, and has important application value.
Detailed Description
The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
The starting materials are commercially available from the open literature unless otherwise specified.
According to the conventional detection method in the field, various performance parameters of the compound are obtained through linear fitting, wherein the specific meanings of the performance parameters are as follows:
Δ n represents optical anisotropy (25 ℃); Δ ε represents the dielectric anisotropy (25 ℃, 1000 Hz); ε | represents the dielectric constant (25 ℃, 1000Hz) in the direction parallel to the molecular axis; cp represents a clearing point; k represents the elastic constant (25 ℃); VHR represents a voltage holding ratio; v0 threshold voltage, capacitive, 20 ℃ (V); γ 1 represents the rotational viscosity (mPa.s, 25 ℃).
Example 1
This example provides a compound having the formula:
this example also provides the synthetic route for the preparation of compound BYLC-01 as follows:
the method comprises the following specific steps:
under the protection of nitrogen, 51.6g of 4-hydroxy-2, 2,6, 6-tetramethylpiperidine-1-oxyl, 27.5g of 2-cyclohexylmalonic acid, 3.7g of 4-dimethylaminopyridine and 400ml of dichloromethane are added into a reaction bottle, stirred for 0.5 hour, controlled at the temperature of minus 10 ℃ to 5 ℃, and added dropwise with a solution consisting of 66.0g of dicyclohexylcarbodiimide and 150ml of dichloromethane to react for 6 hours at room temperature. Conventional work-up, chromatographic purification and elution with n-hexane gave 61.3g of a light pink solid (compound BYLC-01), LC: 99.7%, yield: 82.8 percent.
The BYLC-01 obtained was analyzed by LC-MS and the M/z of the product was 494.1(M +).
Elemental analysis: c: 65.55, H: 9.37, N: 5.66, O: 19.40.
example 2
This example provides a compound having the formula:
this example also provides the synthetic route for the preparation of compound BYLC-02 as follows:
the method comprises the following specific steps:
under the protection of nitrogen, 43.0g of 4-hydroxy-2, 2,6, 6-tetramethylpiperidine-1-oxyl, 26.7g of 3-cyclohexylglutaric acid, 1.8g of 4-dimethylaminopyridine and 500ml of dichloromethane are added into a reaction bottle, stirred for 0.5 hour, controlled at the temperature of-5 ℃ to 5 ℃, and added dropwise with a solution consisting of 31.5g of dicyclohexylcarbodiimide and 80ml of dichloromethane to react for 8 hours at room temperature. Conventional work-up was carried out, purified by chromatography and eluted with n-hexane to give 57.6g of a light pink solid (compound BYLC-02), LC: 99.7%, yield: 88.3 percent.
The BYLC-02 obtained was analyzed by LC-MS and the M/z of the product was 522.1(M +).
Elemental analysis: c: 66.63, H: 9.65, N: 5.36, O: 18.36.
example 3
This example provides a compound having the formula:
the present example also provides a preparation method: 55.4g (compound BYLC-03) of (LC: 99.6%, yield: 82.5 percent.
The BYLC-03 obtained was analyzed by LC-MS and the M/z of the product was 550.1(M +).
Elemental analysis: c: 67.60, H: 9.88, N: 5.09, O: 17.43.
example 4
This example provides a compound having the formula:
the present example also provides a preparation method: using 4-hydroxy-2, 2,6, 6-tetramethylpiperidine-1-oxyl and 2-cyclohexylsuccinic acid as raw materials to react in the same manner as in example 1, 37.2g (compound BYLC-04) was synthesized, LC: 99.6%, yield: 81.4 percent.
The resulting BYLC-04 was analyzed by LC-MS and the M/z of the product was 508.1(M +).
Elemental analysis: c: 65.10, H: 9.52, N: 5.51, O: 18.87.
example 5
This example provides a compound having the formula:
this example was prepared in the same manner as in example 1, except that 43.8g (compound BYLC-05) was synthesized, LC: 99.7%, yield: 86.2 percent.
The BYLC-05 obtained was analyzed by LC-MS and the M/z of the product was 512.1(M +).
Elemental analysis: c: 63.26, H: 8.84, F: 3.71, N: 5.46, O: 18.73.
example 6
This example provides a compound having the formula:
this example was prepared in the same manner as in example 1, except that 18.4g (compound BYLC-06), LC: 99.6%, yield: 78.3 percent.
The BYLC-06 product was analyzed by LC-MS and had M/z of 564.1(M +).
Elemental analysis: c: 68.05, H: 9.98, N: 4.96, O: 17.00.
example 7
This example provides a compound having the formula:
this example was prepared in the same manner as in examples 1 and 2, except that 26.2g (compound BYLC-07) was synthesized, LC: 99.8%, yield: 84.1 percent.
The BYLC-07 obtained was analyzed by LC-MS and the M/z of the product was 520.1(M +).
Elemental analysis: c: 66.89, H: 9.29, N: 5.38, O: 18.44.
according to the technical schemes of the embodiment 1 and the embodiment 2, other compounds provided by the invention can be prepared only by simply replacing corresponding raw materials without changing any substantial operation.
Comparative example
Photostability test
Selecting a liquid crystal mixture, wherein the liquid crystal type is as follows: BYLC-HJ-1100, (manufactured by billions of space-time liquid crystal technologies ltd.) first, the stability of the voltage holding ratio of the liquid crystal mixture (BYLC-HJ-1100) itself was determined, and the stability of the liquid crystal mixture (BYLC-HJ-1100) itself to light was investigated by means of cold cathode ((CCFL) -LCD backlight) illumination in a test cell with electrodes for homeotropic alignment material and planar ITO. In a specific operation, the corresponding test cell is exposed to light for 1000 hours and then the voltage holding ratio is determined in each case after 5 minutes at a temperature of 100 ℃. Setting six parallel experiments in the testing process, wherein the shown values are the average value of six single values and the standard deviation of the six single values, including the condition that the standard deviation is smaller than the precision of the measured value;
thermal stability test
The test cell obtained above was stored in a sealed manner in a conventional laboratory heating cabinet at 100 ℃ for 120 hours, and the voltage holding ratio thereof was measured after 5 minutes at 100 ℃, 1V and 60Hz (VHR, heat, 120 hours).
Experimental example 1
250ppm of the compound of example 1 (i.e.BYLC-01) were added to a liquid crystal mixture BYLC-HJ-1100 (manufactured by billions of spatio-temporal liquid Crystal technology Co., Ltd.) to give a mixture M-1, 250ppm of example 2(BYLC-02) were added to a liquid crystal mixture BYLC-HJ-1100 (manufactured by billions of spatio-temporal liquid Crystal technology Co., Ltd.) to give a mixture M-2, and the stability was investigated in accordance with the method described above, with the results shown in the following table:
photostability test Table 1
Thermal stability test Table 2
As can be seen from the above mixture experimental examples, the starting mixture without using a stabilizer shows considerable reduction in VHR after backlight exposure, whereas the mixture using the compound provided by the present invention has a VHR before exposure superior to that of the mixture of comparative example, and the VHR does not change much after exposure, shows excellent thermal stability, chemical stability, optical stability, etc., has good stability against degradation by thermal and UV exposure and a stable high VHR, effectively reduces the occurrence probability of image delay, maintains a low threshold voltage, improves response time, and prolongs service life.
Experimental example 2
200ppm of the compound of example 3 (i.e., BYLC-03) were added to a liquid crystal mixture BYLC-HJ-1100 (manufactured by billions of space-time liquid Crystal technology Co., Ltd.) to give a mixture M-3, 200ppm of example 4(BYLC-04) were added to a liquid crystal mixture BYLC-HJ-1100 (manufactured by billions of space-time liquid Crystal technology Co., Ltd.) to give a mixture M-4, and the stability was investigated in accordance with the above-mentioned method, and the results are shown in the following table.
Photostability test Table 3
Thermal stability test Table 4
As can be seen from the above mixture experimental examples, the starting mixture without using a stabilizer shows considerable reduction in VHR after backlight exposure, whereas the mixture using the compound provided by the present invention has a VHR before exposure superior to that of the mixture of comparative example, and the VHR does not change much after exposure, shows excellent thermal stability, chemical stability, optical stability, etc., has good stability against degradation by thermal and UV exposure and a stable high VHR, effectively reduces the occurrence probability of image delay, maintains a low threshold voltage, improves response time, and prolongs service life.
Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (15)
1. A light stabilizer having the structure of formula II:
R2represents H;
Z1、Z2independently of one another- (CH)2)-；
m and n are the same or different, and m + n is more than or equal to 0 and less than or equal to 12.
2. Light stabilizer according to claim 1, characterized in that it is selected from one of the following structures:
3. light stabilizer according to claim 1 or 2, characterized in that it is selected from one of the following structures:
4. a process for the preparation of the light stabilizer of claim 1, comprising the steps of:
to be provided with
As raw materials, the raw materials are subjected to esterification reaction to obtain
Wherein R in the compound involved in each step2、m、n、Z1、Z2With R in the resulting compound product2、m、n、Z1、Z2The radicals represented correspond.
5. The production method according to claim 4, wherein, in the esterification reaction,
the feeding molar ratio of (2.0-4.0): 1.
6. the production method according to claim 5, wherein, in the esterification reaction,
the feeding molar ratio of (2.0-3.0): 1.
7. The process according to claim 4 or 5, wherein the esterification reaction is carried out at a temperature of between-30 ℃ and 50 ℃;
and/or the esterification reaction time is 4-12 h;
and/or the catalyst used in the esterification reaction is one or more of dicyclohexylcarbodiimide, concentrated sulfuric acid and p-toluenesulfonic acid.
8. The method according to claim 7, wherein the esterification reaction is carried out at a reaction temperature of-10 ℃ to 30 ℃.
9. The preparation method according to claim 7, wherein the reaction time of the esterification reaction is 6-10 h.
10. A composition comprising the light stabilizer according to any one of claims 1 to 3, wherein the compound stabilizer is added in an amount of 1ppm to 1000 ppm.
11. The composition of claim 10, wherein the compound stabilizer is added in an amount of 1ppm to 800 ppm.
12. The composition of claim 11, wherein the compound stabilizer is added in an amount of 1ppm to 500 ppm.
13. Use of the composition according to any one of claims 10 to 12 in the field of liquid crystal displays.
14. Use of the composition of any one of claims 10 to 12 in a liquid crystal display device.
15. The use according to claim 14, wherein the liquid crystal display device is a TN, ADS, VA, PSVA, FFS or IPS liquid crystal display.
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| CN103773388A (en) * | 2012-10-18 | 2014-05-07 | 默克专利股份有限公司 | Liquid crystal medium, method for the stabilisation thereof and liquid crystal display |
| CN103834414A (en) * | 2012-10-18 | 2014-06-04 | 默克专利股份有限公司 | Liquid-crystalline medium, method for the stabilization thereof, and liquid-crystal display |
| CN105384681A (en) * | 2014-09-02 | 2016-03-09 | 默克专利股份有限公司 | Compounds and liquid-crystalline medium |
| CN108373924A (en) * | 2017-01-30 | 2018-08-07 | 默克专利股份有限公司 | Compound and liquid crystal media |
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| CN102746218A (en) * | 2011-04-21 | 2012-10-24 | 默克专利股份有限公司 | Compounds and liquid crystalline medium |
| WO2013022607A1 (en) * | 2011-08-08 | 2013-02-14 | Transitions Optical, Inc. | Mesogenic stabilizers |
| CN103773388A (en) * | 2012-10-18 | 2014-05-07 | 默克专利股份有限公司 | Liquid crystal medium, method for the stabilisation thereof and liquid crystal display |
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Effective date of registration: 20221117 Address after: Room 519, Circular Economy Promotion Center, Lingang Economic and Technological Development Zone, Cangzhou Bohai New Area, Cangzhou City, Hebei Province, 061109 Patentee after: Hebei Bayi Shikong Pharmaceutical Co.,Ltd. Address before: Block B2-36-01, East District, New Petrochemical Material Science and Technology Industrial Base, Fengjie District, Yanshan District, Fangshan District, Beijing Patentee before: BEIJING BAYI SPACE LCD TECHNOLOGY Co.,Ltd. |