Patent Application
20140160384
The present invention relates to a smectic A phase liquid crystal material, which belongs to the field of optical display materials.
According to the phases, liquid crystal is classified into a nematic phase, a smectic phase and a cholesteric phase. The smectic phase is further classified into the smectic A, B, C, D, E, F, G, H, I, G phases and so on. The nematic liquid crystal and the cholesteric phase have a low viscosity and significant liquidity, while the smectic liquid crystal has a high viscosity. All the liquid crystals have the dielectric anisotropy, and the liquid crystal molecules can be driven by an electric field. After being driven by an electric signal, the molecular arrangement of the liquid crystal molecules having a low viscosity cannot be maintained and can be restored to the original arrangement after the electric signal is cut off. However, after being driven by an electric signal, the molecular arrangement of the liquid crystal molecules having a high viscosity can be maintained, but cannot be restored to the original arrangement, demonstrating a memory effect. Therefore, when being used in displaying, after the electric signal is removed, the smectic liquid crystal can maintain the display content and has a memory effect. As shown in FIG. 1-a, 1-b and 1-c, FIG. 1-a shows a state that an image is displayed, FIG. 1-b shows a state that the displayed image cannot be erased completely, leaving residual images, and FIG. 1-c shows a state that the image can be completely erased.
In 1978, in the article “Electrically induced scattering textures in smectic A phases and their electrical reversal”, D. Coates et al. describes photoelectric driving characteristics of a smectic A phase compound 8CB. At that time, when being used as the smectic A phase liquid crystal display, the smectic A phase material such as 8CB, 80CB has obvious disadvantageous of high drive voltage (generally about 200 V), a period of “aging” time required before use for steady driving, and a narrow range of temperature (about 10° C.) for driving.
In Patent GB2274649A of Dow Corning Corp. in 1994, it is found that a siloxane smectic A phase liquid crystal material can lower the drive voltage (about 70 to 100 V), can work stably without being “aged” for a long period of time and had a broaden temperature range for driving. In WO2010/070606 of Cambridge Enterprise, this type of siloxane liquid crystal materials are used to be mixed with a nematic phase formulation to provide a wide-temperature-range smectic A phase material, which further extends the use temperature of the smectic A phase materials. In WO 2011/115611 A1 of Cambridge Enterprise, it is also proposed that the siloxane polymers are used in mixing of a smectic A phase liquid crystal formulation. The siloxane smectic A phase materials have the smectic A phase, and can induce other non-smectic A phase materials such that the mixed materials obtained by mixing with siloxane liquid crystal materials to have the smectic A phase. Therefore, the siloxane smectic A phase liquid crystal materials are a type of important materials in the smectic A phase formulation.
However, the siloxane smectic A phase liquid crystal has a strong memory effect, so that the displayed image cannot be completely erased, leaving residual images (as shown in
The present invention is directed to a smectic A phase liquid crystal material, which can eliminate residual images of a smectic A phase formulation system of a siloxane liquid crystal and improve the contrast.
The present invention provides a smectic phase-inducing material. Based on this, the present invention further discloses mixing of the liquid crystals. This type of smectic A phase liquid crystal formulations have no residual images, have a high contrast, and the drive voltage is relatively low (about 20 to 50 V).
A smectic A phase liquid crystal material contains at least one heterocyclic compound of Formula (I). The compound of Formula (I) is a substance that can induce the smectic phase and is a heterocyclic liquid crystal material, and has a structure below:
wherein n is 1, 2, 3, or 4, m and p are independently 0, 1, 2, 3, or 4, M1 and M3 are independently 0, 1, or 2, and M2 is 1 or 2;
X and Z are substituted or unsubstituted phenyl rings,
F is a fluorine atom, substituting any one or more of hydrogen atoms on the phenyl ring of X or Z; and
Y is a phenyl ring or a cyclohexyl ring, wherein
when Y is a phenyl ring, T is one or more nitrogen atoms (N) substituting any one or more of carbon atoms on the phenyl ring of Y;
when Y is a cyclohexyl ring, T is one or more oxygen (O) atoms, one or more sulfur (S) atoms and/or one or more boron (B) atoms, substituting any one or more of carbon atoms on the cyclohexyl ring;
and A and B are independently selected from the group consisting of: CN, F, NCS, NCO, CF3, CHF2, CH2F, OCF3, OCHF2, OCH2F, NO2, Cl, CH═CF2 and OCH═CF2; C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkenyl, C1-C20 alkenyloxy, C1-C20 silanyl and C1-C20 siloxanyl, and the halogenated groups thereof; C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkenyl, C1-C20 alkenyloxy and isomers thereof with any —CH2— substituted with —O—, —S—, —CF2—, —CF2O—, —CO—, —COO—, —O—CO—, —O—COO—, —CF═CF—, —CH═CF—, —CF═CH— and —CH═CH—.
The smectic A phase liquid crystal material may further contain at least one ester compound of Formula (II). In addition to the heterocyclic liquid crystal compound, the smectic A phase liquid crystal material formulation of the present invention may further contain an ester liquid crystal compound having a structure of Formula (II):
wherein n1 and n2 are independently 0, 1, 2, 3, or 4,
n3 is 0, 1, or 2, and n4 is 0, 1, 2, or 3;
C and D are independently substituted and unsubstituted phenyl rings;
S1 and S2 are independently a N atom or a F atom, replacing any one or more of C atoms on the phenyl ring when S1 or S2 is a N atom, and replacing any one or more of H atoms on the phenyl ring when S1 or S2 is a F atom;
R1 and R2 are independently selected from the group consisting of: CN, F, NCS, NCO, CF3, CHF2, CH2F, OCF3, OCHF2, OCH2F, NO2, Cl, CH═CF2 and OCH═CF2; C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkenyl, C1-C20 alkenyloxy, C1-C20 silanyl and C1-C20 siloxanyl, and the halogenated groups thereof; C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkenyl, C1-C20 alkenyloxy and isomers thereof with any —CH2— substituted with —O—, —S—, —CF2—, —CF2O—, —CO—, —COO—, —O—CO—, —O—COO—, —CF═CF—, —CH═CF—, —CF═CH— and —CH═CH—.
The smectic A phase liquid crystal materials may further contain at least one ionic compound. In the smectic A phase liquid crystal formulation of the present invention, an ionic compound may be added.
In The smectic A phase liquid crystal material of the present invention, the content of the compound of Formula (I) and (II) is 1 wt % to 100 wt %, preferably 10 wt % to 100 wt %, based on the total weight of the mixed liquid crystal layer; and the content of the ionic compounds is 0.0001 wt % to 10 wt %, preferably 0.0001 wt % to 1 wt %, based on the total weight of the mixed liquid crystal layer.
In the smectic A phase liquid crystal formulation of the present invention, in addition to the heterocyclic liquid crystal material of Formula (I) and the ester liquid crystal material of Formula (II), a nematic phase liquid crystal formulation, nematic liquid crystal compounds, other liquid crystal compounds or rod-like compounds having no liquid crystal properties may be added.
In addition, a dichromatic dye, a UV glue and similar materials may be further added to The smectic A phase liquid crystal material.
In the following, classification and preference of the heterocyclic compound of Formula (I), the ester compound of Formula (II) and the ionic compound in the smectic A phase liquid crystal formulation of the present invention are further described in detail.
1. Heterocyclic Compound
(1) The heterocyclic liquid crystal compound of Formula (I) may be a pyridine compound of Formula (III), where Y is a phenyl ring and T is a nitrogen atom.
In Formula (III), letter symbols A, B, X, Z, F, m, p, M1, M2 and M3 have the same meaning as that in Formula (I).
(2) The heterocyclic liquid crystal compound of Formula (I) may also be a pyrimidine heterocyclic liquid crystal compound of Formula (IV), where Y is a phenyl ring and T is a nitrogen atom.
In Formula (IV), letter symbols have the same meaning as that in Formula (I).
(3) The heterocyclic liquid crystal compound of Formula (I) may also be a dioxane heterocyclic liquid crystal compound of Formula (V), where Y is a cyclohexyl ring and T is an oxygen atom.
In Formula (V), letter symbols have the same meaning as that in Formula (I).
(4) The heterocyclic liquid crystal compound of Formula (I) may also be a dithiane heterocyclic liquid crystal compound of Formula (VI), where Y is a cyclohexyl ring and T is a sulfur atom.
In Formula (VI), letter symbols have the same meaning as that in Formula (I).
(5) The heterocyclic liquid crystal compound of Formula (I) may also be a dioxaborinane heterocyclic liquid crystal compound of Formula (VII), where Y moiety is a boron-containing heterocyclic ring.
In Formula (VII), letter symbols have the same meaning as that in Formula (I).
2. Ester Compound
(1) The ester liquid crystal compound of Formula (II) may be a compound having a phenyl ring attached adjacently to the ester linkage and having a structure of Formula (VIII).
In Formula (VIII), F represents a fluorine atom, n5 is 0, 1, 2, 3, or 4, indicating that the hydrogen atoms on the phenyl ring adjacent to the ester linkage may be unsubstituted or substituted with fluorine, n6 is 0, 1, or 2; and other letters R1, R2, S1, S2, C, D, F, n1, n2 and n3 have the same meaning as that in Formula (II).
(i) The ester liquid crystal compound of Formula (VIII) may have a structure of Formula (IX), wherein C and D are independently substituted or unsubstituted phenyl rings, S1 is an N atom and may replace any C atom on the phenyl ring, and S2 is an F atom and may replace any H atom on the phenyl ring.
In Formula (IX), letters have the same meaning as that in Formula (VIII).
(ii) The ester liquid crystal compound of Formula (VIII) may have a structure of Formula (X), where C and D are independently substituted or unsubstituted phenyl rings, and S1 and S2 are an F atom and may replace any H atom on the phenyl ring.
In Formula (X), letters have the same meaning as that in Formula (VIII).
(iii) The ester liquid crystal compound of Formula (VIII) may have a structure of Formula (XI), wherein C and D are phenyl ring, and S1 and S2 are an N atom and may replace any C atom on the phenyl ring.
In Formula (XI), letters have the same meaning as that in Formula (VIII).
(iv) The ester liquid crystal compound of Formula (VIII) may have a structure of Formula (XII), where C and D are independently substituted or unsubstituted phenyl rings, S1 is an F atom and may replace any H atom on the phenyl ring, and S2 is an N atom and may replace any C atom on the phenyl ring.
In Formula (XII), letters have the same meaning as that in Formula (VIII).
(2) The ester liquid crystal compound of Formula (II) may have a compound having a pyridine ring attached adjacently to an ester linkage and having a structure of Formula (XIII) or (XIV).
In Formula (XIII) or (XIV), letters have the same meaning as that in Formula (VIII).
(i) The ester liquid crystal compound of Formula (XIII) or (XIV) may have a structure of Formula (XV) or (XVI), where C and D are independently substituted or unsubstituted phenyl rings, S1 is an N atom and may replace any C atom on the phenyl ring, and S2 is an F atom and may replace any H atom on the phenyl ring.
In Formula (XV) or (XVI), letters have the same meaning as that in Formula (VIII).
(ii) The ester liquid crystal compound of Formula (XIII) or (XIV) may have a structure of Formula (XVII) or (XVIII), where C and D are independently substituted or unsubstituted phenyl rings, and S1 and S2 are an F atom and may replace any H atom on the phenyl ring.
In Formula (XVII) or (XVIII), letters have the same meaning as that in Formula (VIII).
(ii) The ester liquid crystal compound of Formula (XIII) or (XIV) may have a structure of Formula (XIX) or (XX), where C and D are independently substituted or unsubstituted phenyl rings, and S1 and S2 are an N atom and may replace any C atom on the phenyl ring.
In Formula (XIX) or (XX), letters have the same meaning as that in Formula (VIII).
(iv) The ester liquid crystal compound of Formula (XIII) or (XIV) may have a structure of Formula (XXI) or (XXII), where C and D are independently substituted or unsubstituted phenyl rings, S1 is an F atom and may replace any H atom on the phenyl ring, and S2 is an N atom and may replace any C atom on the phenyl ring.
In Formula (XXI) or (XXII), letters have the same meaning as that in Formula (VIII).
3. Ionic Compound
In the smectic A phase liquid crystal formulation of the present invention, the ionic compound may be selected from: sodium laurylsulfate, ethyl triphenylphosphonium iodide, (ferrocenylmethyl)trimethylammonium iodide, 1,2-dimethyl-3-butylimidazole hexafluorophosphate, tetraethylamine para-toluenesulfonate, phenyltriethylammonium iodide, 1-octyl-3-methylimidazole hexafluorophosphate, bis(tetra-n-butylamine)bis(1,3-dithiole-2-thione-4,5-dithiol)palladium (II), tetra-n-butyl bis(1,3-dithiole-2-thione-4,5-dithiol)nickel (III), bis(tetra-n-butylammonium) bis(1,3-dithiole-2-thione-4,5-dithiol)zinc, bis(tetra-n-butylammonium)tetracyanodiphenoquinodimethane, tetra-n-butylammonium bromide, cetylammonium perchlorate, cetyltetraammonium bromide, 1-butyl-3-methylimidazole tetrachloride ferrate, methyltriphenylphosphonium iodide, tetraphenylphosphonium iodide, cetyltrimethyl ammonium bromide, cetyltrimethyl ammonium perchlorate, cetyldimethylbenzylammonium chloride, dodecyl pyridine bromide, cetyl pyridine bromide, cetyl pyridine chloride and cetyltributylammonium bromide.
The smectic A phase liquid crystal material according to the present invention may be used in a smectic liquid crystal display device or a dimming device, especially in a device with a dual-frequency drive mode of low-frequency frosting and high-frequency clearing.
FIG. 1-a, 1-b and 1-c show several different states of a smectic A phase liquid crystal display screen respectively, where FIG. 1-a shows a state that an image is displayed, FIG. 1-b shows a state that the displayed image cannot be erased and residual images are remained, and FIG. 1-c shows a state that the image can be completely erased.
FIG. 3-a, FIG. 3-b and FIG. 3-c show different working principles of several typical smectic A phases, where FIG. 3-a shows a first generation smectic A phase material, with 8CB as representative, FIG. 3-b shows a second generation smectic A phase materials, with a siloxane liquid crystal as representative, and FIG. 3-c shows a new generation (third generation) smectic A phase material, with a heterocyclic liquid crystal as representative.
The drive display principle of the smectic phase liquid crystal applied to display is shown in
In a low frequency electric field (≦100 Hz), long-chain conductive ions (the conductive material, such as added organic conductive ions, such as tetrabutylammonium bromide, sodium laurylsulfate, cetyltrimethyl ammonium perchlorate, and tetraphenylphosphonium iodide) begin to move back and forth under the electric field force, thereby agitating and disturbing the smectic layer in ordered arrangement. This behavior is similar to the dynamic scattering effect of the nematic liquid crystal, and difference lies in that, the vortex plane formed during the smectic dynamic scattering is perpendicular to the direction of the applied electric field, while the vortex plane formed during the dynamic scattering of the nematic liquid crystals is parallel to the direction of the applied electric field. The molecular arrangement of the smectic liquid crystal is in a disordered state as shown in the left side in the
In high-frequency electric field (≧1000 Hz), the organic conductive ions move back and forth slightly, and the agitation effect on the liquid crystal is negligible. Herein, under the electric field force, the major axis of the liquid crystal molecules are oriented in parallel to the direction of the electric field; when the electric signal is stopped, this regular arrangement is maintained, as shown in the right side in
The molecular arrangement of the smectic liquid crystal can also be remained in various states where the light transmittance is different, so as to achieve display at different grey levels. Therefore, the smectic liquid crystal has multi-stable characteristics.
Difference in characteristics and working principle of several types of smectic A phase materials are analyzed (as shown in
When the smectic A phase materials are subject to clearing, the liquid crystal molecules are arranged in the direction of the electric field due to dielectric anisotropy of liquid crystals itself. The liquid crystal molecules are disarranged by ions to cause frost, because different types of smectic A phase ions have different disarrangement mechanisms. Therefore, the principles of operation for different smectic A phase materials are differed in frosting mechanism.
FIG. 3-a shows a first generation smectic A phase material with 8CB as representative, which has a requirement on the electrode surface, and requires that the electrode surface needs to be rough, and needs to be driven and “aged” by a high initial voltage for a period of time for steady driving. Ions need to move in the smectic layer to exert the disturbing function, that is, the movement direction is perpendicular to the direction of an applied electric field, which requires that the conductivity (σ⊥) in the direction of the liquid crystal material perpendicular to molecular direction is greater than the conductivity (σ∥) in the direction parallel to the molecular direction. 8CB has a σ∥/σ⊥ value in the range of 0.5 to 1, and a not great conductivity in the direction perpendicular to the molecular direction, while the rough electrode surface allow the generation of an electric field perpendicular to the direction electric field, between the adjacent rough surfaces. Therefore, in low-frequency driving, ions first move in the smectic layer adjacent to the rough electrode surface, and thereby gradually driving other liquid crystal layers to move together, thereby finally reaching the frosting state.
FIG. 3-b shows a second generation smectic A phase material, with a siloxane liquid crystal as representative, which has no requirement on the electrode surface, and an electrode having a smooth surface can be used, and no aging is required for steady driving. The reason is that after the siloxanyl is introduced, this type of materials has a greater conductivity in the direction perpendicular to the molecular direction, and the σ∥/σ⊥ value is about 0.03. The ion additive is enriched in the siloxane layer, that is, between the adjacent smectic layers, and when electricity is applied, electrons move in the direction perpendicular to the electric field direction and between the smectic layers, thereby disturbing the liquid crystal layer to reach the frosting state.
FIG. 3-c shows a new generation (third generation) smectic A phase material, with a heterocyclic liquid crystal as representative, which also has no requirement on the electrode surface, an electrode having a smooth surface can be used, and no aging is required for steady driving. Due to the introduction of a heteroatom into the rigid nuclear moiety of the molecule, the conductivity of this type of materials in the perpendicular direction is increased. Ions are enriched around the heterocyclic ring, that is, in the smectic layer, and when electricity is applied, the ions move in the direction perpendicular to the direction of the electric field from the center of the smectic layer, thereby disturbing the liquid crystal layer to reach the frosting state. Since the ions directly disturb the liquid crystal layer at the center of the smectic layer when being subjected to frosting, so the frosting can be achieved easily and the degree of disorder of the smectic layer is high, thereby overcoming the memory effect and removing the residual images, and providing a strong light scattering and a high contrast at the frosting state. In addition, the dielectric anisotropy Δ∈ of the siloxane liquid crystal is generally as low as about 0.8, and the dielectric anisotropy Δ∈ of heterocyclic liquid crystal is generally as high as 8. The higher Δ∈ is, the faster the response of the liquid crystal to the electric field is. Therefore, this type of materials has a drive voltage lower than that of the siloxane liquid crystal material.
The functions of components of The smectic A phase liquid crystal material formulation of the present invention are as follows.
The smectic A phase-inducing component: The heterocyclic liquid crystal of Formula (I) function to induce the smectic phase. A smectic liquid crystal is formed as a result of a lateral attractive force between liquid crystal molecules higher than a terminal attractive force between the liquid crystal molecules, and introduction of a heteroatom into the rigid moiety of the liquid crystal molecule may increase the lateral attractive force between the liquid crystal molecules, so when being the smectic A phase, this type of liquid crystals can easily induce other non-smectic A phase materials to be the smectic A phase.
A component that increases the conductivity (σ⊥) in the direction perpendicular to the molecular direction: The ester liquid crystal material of Formula (II) functions to increase σ⊥. The reason is that the lone paired electrons are enriched in an outer orbit of oxygen nucleus, oxygen atom incorporated into the heterocyclic system further interacts with a heteroatom to provide a high conductivity in the direction perpendicular to the molecular direction, and frosting is more easily achieved by addition of an ester liquid crystal.
Other components optionally added: A low-viscosity liquid crystal material (fluorine-containing liquid crystal or cyclohexyl ring liquid crystal) is added for a fast response; a liquid crystal material having a great birefringence (such as alkyne liquid crystal) is added for a high contrast; a dichromatic dye is added for color display; and a UV glue is added for reduction of the working viscosity and enhancement of the adhesion of hollow liquid crystal cells.
The smectic A phase liquid crystal material of the present invention may not contain the ester liquid crystal material of Formula (II), if The smectic A phase liquid crystal material of the present invention does not contain the ester liquid crystal material of Formula (II), the drive voltage is increased.
The heterocyclic liquid crystal material and the ester liquid crystal material used in the present invention may be obtained through common chemical synthesis or other commercial way, and the other auxiliary materials, such as the nematic formulation, other liquid crystal materials or organic ionic compounds, may be directly purchased from the market.
The processes for preparing the heterocyclic liquid crystal of Formula (I) and the ester liquid crystal materials of Formula (II) are exemplified as follows.
The representative monomers are listed in Table 1:
Preparation of L1
Preparation of L1 Intermediate 1
In a three-necked round-bottomed flask, 23 g (1.1 eq) 1-bromo-n-heptane and 37 g (1.0 eq.) triphenylphosphine are added in sequence, purged with nitrogen gas and then heated with stirring for 5 hours. The reaction liquid is filtered by suction, and the filter pad is washed in 200 ml×3 ethyl acetate and dried to give 33 g white solid 1.
Preparation of L1 Intermediate 2
Under anhydrous and anaerobic conditions, in a four-necked rounded-bottom flask, 100 mL dry THF and 33 g (1.2 eq) intermediate 1 are added in sequence, and upon fall of temperature of the reaction system to −40° C., 35 ml n-butyl lithium is added dropwise; afterwards, the reaction system is warmed up to 0° C. with stirring for 1 hour. Upon fall of temperature of the reaction system to −15° C., 11.6 g (1.2 eq) 2-bromo-5-aldo-pyridine is added dropwise, and then the reaction system is warmed up at refluxing with stirring for 3 hours. The reaction liquid is hydrolyzed, extracted with petroleum ether, and then was subject to column chromatography to give 11 g intermediate 2. [H-NMR (400M, CDCl3) δ (ppm): 8.6 (s, 1H), 7-8 (d, 2H), 6.5 (d, 1H), 6.1 (m, 1H), 1.2-1.4 (m, 8H), 0.95 (m, 3H)].
Preparation of L1 Intermediate 3:
In a four-necked rounded-bottom flask, 50 mL anhydrous ethanol and 10 g (1.0 eq) intermediate 2 are added in sequence; the oxygen is removed from the reaction system, then palladium/carbon (0.1 g) is added, then H2 is fed; the reaction system is stirred at 40° C. for 8 hours; the reaction liquid is filtered for removal of palladium/carbon and concentrated to give total of 10.0 g intermediate 3. [H-NMR (400M, CDCl3) δ (ppm): 8.6 (s, 1H), 7-8 (d, 2H), 2.6 (m, 2H), 1.2-1.7 (m, 12H), 0.95 (m, 3H)].
Preparation of L1
In a flask, 40 mL anhydrous ethanol, 40 mL deionized water, 13 g (2.5 eq) potassium carbonate, 10 g (1.0 eq) intermediate 3 and 6.2 g (1.2 eq) 4-fluorophenylboronic acid are added in sequence, the oxygen is removed from the reaction system, then 0.1 g Pd(dppf)2Cl2 is added; the reaction system is warmed up at refluxing, and the reaction is carried out for 8 hours; the reaction liquid is extracted with 100 mL ethyl acetate, and purified by column chromatography to give total of 9.0 g product. [H-NMR (400M, CDCl3) δ (ppm): 8.6 (s, 1H), 7-8 (d, 6H), 2.6 (m, 2H), 1.2-1.7 (m, 12H), 0.95 (m, 3H)].
Preparation of L2
The preparation process is same as that of L1, except that 4-propylphenylboronic acid is used as the raw material. L2 [H-NMR (400M, CDCl3) δ (ppm): 8.6 (s, 1H), 7-8 (d, 6H), 2.6 (m, 4H), 1.2-1.7 (m, 14H), 0.95 (m, 6H)].
Preparation of L4
The preparation process is same as that of L1, except that p-cyanophenylboronic acid is used as the raw material. L4 [H-NMR (400M, CDCl3) δ (ppm): 8.6 (s, 1H), 7-8 (d, 6H), 2.6 (m, 2H), 1.2-1.7 (m, 12H), 0.95 (m, 3H)].
Preparation of L3
The process the same as that in preparation of L1 intermediates is used to prepare L3 intermediate 1, L3 intermediate 2 and L3 intermediate 3.
Preparation of L3 Intermediate 4
In a flask, 20 mL anhydrous ethanol, 10 mL deionized water, 13 g (2.5 eq) potassium carbonate, 5.1 g (1.0 eq) intermediate 3 and 3.4 g (1.3 eq) 4-aminophenylboronic acid are added in sequence, the oxygen is removed from the reaction system, and then 0.05 g Pd(Ph3P)4 is added; the reaction system is warmed up at refluxing, and the reaction is carried out for 8 hours; the reaction liquid is purified by column chromatography to give 5.2 g product. [H-NMR (400M, CDCl3) δ (ppm): 8.6 (s, 1H), 7-8 (d, 6H), 5.4 (s, 2H), 2.6 (m, 2H), 1.2-1.7 (m, 12H), 0.95 (m, 3H)].
Preparation of L3
In a flask, 5.0 g (1.0 eq.) L3 intermediate 4 is dissolved in 30 mL dichloromethane; 15 mL water and 5.3 g (3 eq.) calcium carbonate are added; the reaction system is cooled to 0° C.; 2.65 g (1.3 eq.) thiophosgene is added dropwise, and stirred for 6 hours at 0° C.; the reaction liquid i purified by column chromatography to give 4.2 g product. [H-NMR (400M, CDCl3) δ (ppm): 8.6 (s, 1H), 7-8 (d, 6H), 2.6 (m, 2H), 1.2-1.7 (m, 12H), 0.95 (m, 3H)].
Preparation of L5
Preparation of L5 Intermediate 1
In a reaction system, the solvent DMF (dry), 5 g (1.0 eq.) 2-bromo-5-hydroxypridine, 6.1 g (1.1 eq.) 1-bromooctane, 9.9 g (2.5 eq.) potassium carbonate and 0.5 g (0.1 eq.) potassium iodide are added and reacted with stirring for 4 hours at 90° C.; and the reaction liquid is purified to give 8.0 g product 1. [H-NMR (400M, CDCl3) δ (ppm): 8.7 (s, 1H), 7-8 (d, 2H), 4.1 (m, 2H), 1.2-1.7 (m, 12H), 0.95 (m, 3H)].
Preparation of L5 Intermediate 2
In a reaction system, 30 mL anhydrous ethanol, 30 mL deionized water, 7.0 g (1.0 eq) L5 intermediate 1, 8.44 g (2.5 eq) potassium carbonate and 4.4 g (1.3 eq) 4-aminophenylboronic acid are added in sequence; the oxygen is removed from the reaction system; then 0.1 g Pd(Ph3P)4 is added; the reaction is warmed up at refluxing, and the reaction is carried out for 16 hours, and the reaction liquid is purified by column chromatography to give 6.5 g product 2. [H-NMR (400M, CDCl3) δ (ppm): 8.5 (s, 1H), 7-8 (d, 6H), 5.1 (s, 2H), 4.0 (m, 2H), 1.2-1.7 (m, 12H), 0.95 (m, 3H)].
Preparation of L5
In a flask, 6.0 g (1.0 eq.) L5 intermediate 2 is dissolved in 20 mL dichloromethane; 10 mL water and 6.0 g (3 eq.) calcium carbonate are added; the reaction system is cooled to 0° C.; 3.0 g (1.3 eq.) thiophosgene is added dropwise, and stirred for 6 hours at 0° C.; the reaction liquid is purified by column chromatography to give 5.5 g product. [H-NMR (400M, CDCl3) δ(ppm): 8.5 (s, 1H), 7-8 (d, 6H), 3.9 (m, 2H), 1.2-1.7 (m, 12H), 0.95 (m, 3H)].
Preparation of L6
Preparation of L6 Intermediate 1
In a flask, 82.8 g (1.2 eq.) potassium carbonate and 100 ml morpholine are added; a stir bar, a thermometer and a constant pressure dropping funnel are installed; the reaction system is cooled externally to 0° C. and less, and 71 g (1.0 eq.) n-nonyl aldehyde is added dropwise; after complete addition for about 30 minutes, the reaction system is maintained for 8 hours at 0 to 5° C.; the reaction liquid is filtered by suction; the funnel is flushed with 200 ml petroleum ether (90 to 105° C.) several times, the filtrate is concentrated and distilled at reduced pressure, and the products of 94-96° C. are collected to give 52 g colorless liquid product 1.
Preparation of L6 Intermediate 2
In a flask, 100 ml dichloromethane, 18 g (1.2 eq.) triethyl orthoformate and 21 g (1.0 eq.) L6 intermediate 1 are added. A stirring bar, a thermometer and a dropping funnel are installed, and the temperature is decreased to below −40° C.; and then 17 g (1.2 eq.) solution of boron trifluoride in diethyl ether is added dropwise with the temperature being controlled to −40 to −45° C.; after complete addition for about 1 hour, the reaction system is maintained for 3 hours at −40° C. and naturally warmed up to 25° C., and a mixture of 3 g sulfuric acid, 57 ml water and 12 ml ethanol is added and hydrolyzed for 3 hours; after separation, the water layer is extracted twice with dichloromethane, and the organic phases are combined and washed with 5% aqueous potassium carbonate solution three times, and is washed with water to be neutral, and is dried over anhydrous magnesium sulfate and concentrated to give 19 g intermediate 2.
Preparation of L6 Intermediate 3
To a reaction system, 150 ml methanol and 2.5 g sodium wire are added, and an exothermic reaction is carried out at refluxing to give a sodium methoxide solution; after the reaction system is cooled to 25° C., 19.7 g (1.0 eq.) p-nitrobenzamidine hydrochloride and 28 g (1.5 eq.) L6 intermediate 2 are added, N2 is fed for protection; after about 30-hour reaction at a temperature controlled to be 30° C., the reaction liquid is frozen at −10° C. and is filtered by suction, and the cake is washed with a small amount of petroleum ether (cold) 3 times and washed with water 3 times, is dried by suction and then is recrystallized once in 3-fold ethanol to give 6 g L6 intermediate 3 as an off-white solid. [H-NMR (400M, CDCl3) δ (ppm): 8.3 (s, 2H), 7-8 (d, 4H), 2.7 (m, 2H), 1.2-1.7 (m, 10H), 0.95 (m, 3H)].
Preparation of L6 Intermediate 4
In a one-necked flask, 6 g (1.0 eq.) L6 intermediate 3, 2 g palladium/carbon and 200 ml ethanol are added, purged with nitrogen gas and heated to 60° C.; 6 g (2.0 eq.) hydrazine hydrate is slowly added dropwise and refluxed for 1 hour; the reaction liquid is cooled to 25° C., and is filtered by suction; the filtrate is concentrated and recrystallized in 2-fold petroleum ether to give 4.5 g L6 intermediate 4 as an off-white solid. [H-NMR (400M, CDCl3) δ (ppm): 8.3 (s, 2H), 7-8 (d, 4H), 5.6 (m, 2H), 2.7 (m, 2H), 1.2-1.7 (m, 10H), 0.95 (m, 3H)].
Preparation of L6
In a three-necked flask, 4.5 g (1.0 eq.) L6 intermediate 4, 30 ml chloroform, 5 g (2.5 eq.) calcium carbonate and 20 ml deionized water are added at a temperature of 0° C., and 5 g (1.6 eq.) thiophosgene is added dropwise; and then the reaction system is stirred for 3 hours at a temperature controlled to be 0-5° C.; the reaction system is filtered by suction, the cake is washed in 200 ml dichloromethane, and the filtrate is separated, concentrated and is subject to column chromatography to give 4 g white solid product. [H-NMR (400M, CDCl3) δ (ppm): 8.3 (s, 2H), 7-8 (d, 4H), 2.7 (m, 2H), 1.2-1.7 (m, 10H), 0.95 (m, 3H)].
Preparation of L7
L7 intermediate 1, L7 intermediate 2 and L7 are prepared in the same manner as the former three processes for preparation of L6, except that after preparation of L7 intermediate 2, L7 intermediate 2 is immediately reacted to prepare L7, where the raw material is 3,4-difluoro benzamidine.
L7 final product [H-NMR (400M, CDCl3) δ (ppm): 8.5 (s, 2H), 7-8 (d, 3H), 2.7 (m, 2H), 1.2-1.7 (m, 10H), 0.95 (m, 3H)].
Preparation of L8 (many synthetic processes are available for this type of monomers; herein convenient processes are exemplified):
To a reaction system, 120 mL dichloromethane, 15 g (1.0 eq.) 4-pentylbenzoic acid, 12.5 g (1.02 eq.) 3-fluoro-4-nitrophenol, 16.9 g (1.05 eq.) DCC and a catalytic amount of DMAP (0.05 g) are added and stirred for 8 hours at 30° C. for reaction, and then are processed to give 20 g product. [H-NMR (400M, CDCl3) δ: (ppm) 7-8 (d, 7H), 2.5 (m, 2H), 1.2-1.7 (m, 8H), 0.95 (m, 3H)].
Preparation of L9
The preparation method is the same as that of L8, except only that 2-fluoro-4-pentylbenzoic acid and 3-fluoro-4-cyanophenol are used. [H-NMR (400M, CDCl3) δ: (ppm) 7-8 (d, 6H), 2.5 (m, 2H), 1.2-1.7 (m, 8H), 0.95 (m, 3H)].
Preparation of L10
The preparation method is the same as that of L8, except that 2-fluoro-4-hydroxypridine is used. [H-NMR (400M, CDCl3) δ: (ppm) 8.4 (s, 1H), 7-8 (d, 6H), 2.5 (m, 2H), 1.2-1.7 (m, 8H), 0.95 (m, 3H)].
Preparation of L11
The preparation method is the same as that of L8, except that 2-fluoro-4-hydroxyphenol and 5-octyloxy-2-carboxylic acid pyridine are used. [H-NMR (400M, CDCl3) δ: (ppm) 9.0 (s, 1H), 7-8.5 (d, 5H), 4.0 (m, 2H), 1.2-1.7 (m, 12H), 0.95 (m, 3H)].
1. By applying the new generation smectic A phase liquid crystal formulation material of the present invention to the existing smectic liquid crystal display device, the occurrence of residual images can be effectively avoided.
2. By applying the new generation smectic A phase liquid crystal formulation material of the present invention to the existing smectic liquid crystal display device, the contrast of the existing display device can be effective improved. The contrast acceptable for human eyes is generally 5:1, while the new generation smectic A phase liquid crystal formulation material of the present invention has a contrast higher than 10 without any optical processing aids, thereby providing good visual effects.
3. The drive voltage for the new generation smectic A phase liquid crystal formulation material of the present invention is low (20-50 V), thereby saving energy.
In the following, the present invention is further described with reference to the accompanying drawings and specific embodiments, which are not intended to limit the scope of the present invention.
In the present invention, mixing and tests are performed following the following liquid crystal mixing experimental procedure:
1. first, liquid crystal materials are weighed at a specific ratio, and are added one by one into a glass vial;
2. the vial contained the materials is placed into an oven and heated until the liquid crystals is completely clear;
3. the liquid crystal is fully and uniformly mixed through ultrasonic shock or magnetic stirring;
4. the mixed liquid crystal is heated and filled in vacuum by a crystal filler into a hollow liquid crystal cell having a thickness of 12 μm thickness and a size of 2.8 inch, as shown in
5. after cooling, the liquid crystal cell is sealed with a UV glue, and then an integrated control circuit with an IC drive chip is bonded to electrodes of the—liquid crystal cell (as shown in
6. the IC chip for the liquid crystal cell is connected to the drive circuit board, the liquid crystal cell is driven by an external power supply (that can supply an alternating voltage of 0 to 70 V), image scanning is performed at 2 KHz and frosting is performed at 30 Hz to erases the image. The whole device is shown in
7. the liquid crystal cell was tested for the contrast.
8. the liquid crystal cell is driven cyclically (the image is scanned continuously at a high frequency, as shown in
The contrast of the smectic liquid crystal display is a ratio of the light transmittance at the clearing state to the light transmittance at the frosting state, and in general, all materials have a substantially the same light transmittance at the clearing state; therefore, the contrast mainly depends on the light transmittance of the material at the frosting state, that is, the scattering state of the smectic liquid crystal material.
Since no standard method for testing the contrast of the reflective smectic liquid crystal display device is available in the industry, multiple universal and simple methods are used to test the contrast, and finally, a test method having a visual effect closer to that of human eye is selected and used as the standard of verification and comparison.
Contrast test method: microscopy method
This test method is a simple method that is often used for testing and has measurement results close to human eyes, and the apparatus used by the method is shown in
Test procedure:
1. A sample is placed on an objective table, and the focal length of the microscope is adjusted, so that the sample can be imaged clearly.
2. The sample was removed, and the HL-CR-11A software was used to compute with the numerical values at each points collected by CCD as follows: Yi=0.299*R+0.587*G+0.114*B.
3. The Yi values at each points are summed to give a normalized factor Y0=ΣYi.
4. The sample is placed onto the objective table, and the HL-CR-11A software is used to compute the Y value at this point Y=ΣYi.
5. The transmittance of the sample is defined as T=(Y/Y0)*100%.
6. For the smectic liquid crystal sample, the transmittance at clearing state Tc=(Yc/Y0)*100%, the transmittance at frosting state Ts=(Ys/Y0)*100%, and the contrast Cr=Tc/Ts.
In brief, first, in the situation that no liquid crystal cell is placed on the objective table and a light source (light ray emitted from a halide lamp equipped on the microscope) directly enter the objective lens, the light rays are collected by a receiver, the receiver converts the collected light rays into corresponding electric signals and send the electric signals to software of a computer, and the software records an electric signal B at this point as a basic reference value. Next, the luminance L of the light source at this point is fixed, the liquid crystal cell is placed on an objective table and the height of the objective table is adjusted, so that the liquid crystal cell can be clearly observed from an ocular lens; the receiver converts the light ray energy collected from the liquid crystal cells at the clearing state and the frosting state into an electric signal and sent the electrical signal to the computer. The computer software compares the light ray energy received at the clearing state and the frosting state with the basic reference. That is, the electric signal Q of the light ray energy received at the clearing state is divided by the basic reference value B to obtain a transmittance value QL at the clearing state, the electric signal M of the light ray energy received at the frosting state is divided by the basic reference value B to obtain a transmittance value ML at the frosting state, and the transmittance at the clearing state is divided by the transmittance at the frosting state to obtain a contrast value QL/ML*100%.
In the following embodiments, mixing is performed according to the crystal mixing method described in the present invention, and the contrast is tested.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded, and the contrast was tested. In Embodiment 1, PDLC-004 was available from Shijiazhuang Huarui Technology Co. ltd, and SLC1717 and 1L1117600-200 were available from Shijiazhuang Yongshen Huaqing Liquid Crystal Co. Ltd.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 30 to 40 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 30 to 40 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 30 to 40 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 30 to 40 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 30 to 40 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 30 to 40 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 30 to 40 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 30 to 40 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 18:1, no residual image occurred after aging 5000 times, and the drive voltage was 30 to 40 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 20 to 30 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded to give a purple-red display screen. The contrast was tested to be 12:1, no residual image occurred after aging 5000 times, and the drive voltage was 30 to 40 V.
The mischcrystal was in a clearing state at room temperature, was filled in vacuum into the 2.8-inch screen at room temperature, sealed and bonded, solidified by UV to give a smectic A phase liquid crystal display screen. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 30 to 40 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 40 to 50 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 40 to 50 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 40 to 50 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 40 to 50 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 40 to 50 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 40 to 50 V.
The mischcrystal was heated to be clear, filled in vacuum into a 2.8-inch screen, sealed and bonded. The contrast was tested to be 11:1, no residual image occurred after aging 5000 times, and the drive voltage was 40 to 50 V.
The smectic A phase liquid crystal formulation of the present invention also may be used as a dimming media, and a dimming glass having a large size can be obtained by increasing the pixel and increasing the size of the glass (as shown in
The new generation smectic A phase liquid crystal material formulation of the present invention is different from the first generation smectic A phase liquid crystal and the second generation smectic A phase liquid crystal in the working principle, and are significantly superior to the previous smectic A phase formulations in practical effects. By applying the smectic A phase formulation of the present invention to a display device, the displayed image can be completely erased without any residual images, and the image can be completely erased after long-term drive and long-term use, the contrast is high and is generally higher than 10, and the drive voltage is low and is generally 20 to 50 V.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201210331994.6 | Sep 2012 | CN | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/CN2012/082167 | 9/27/2012 | WO | 00 | 9/3/2013 |
