CN111040775B - A wide temperature liquid crystal composition, a wide temperature polymer dispersed liquid crystal composition and a wide temperature polymer dispersed liquid crystal film - Google Patents

Abstract

The invention provides a wide-temperature liquid crystal composition for polymer dispersed liquid crystal, a wide-temperature polymer dispersed liquid crystal composition and a wide-temperature polymer dispersed liquid crystal film, wherein the liquid crystal composition consists of at least two liquid crystal molecules, and the wide-temperature polymer dispersed liquid crystal film prepared from the wide-temperature liquid crystal composition has the advantages of low driving voltage, quick response, good optical performance, high reliability, wide use temperature range and the like, and solves the problems of poor reliability and narrow working temperature range of a PDLC product in the prior art.

Description

A wide temperature liquid crystal composition, a wide temperature polymer dispersed liquid crystal composition and a wide temperature polymer dispersed liquid crystal film

Technical Field

The present invention belongs to the technical field of liquid crystal materials and liquid crystal display devices, and relates to a liquid crystal composition, in particular to a wide temperature liquid crystal composition, and particularly to a wide temperature liquid crystal composition, a wide temperature polymer dispersed liquid crystal composition and a wide temperature polymer dispersed liquid crystal film.

Background Art

Polymer Dispersed Liquid Crystal (PDLC) is a new type of composite liquid crystal material with optoelectronic properties. The research on this liquid crystal material began with an accidental discovery decades ago. It is a two-phase system composed of liquid crystal and polymer. Through UV or heating methods, small molecule liquid crystals are dispersed in a transparent polymer system to form micron-sized or nano-sized liquid crystal droplets. The polymer system provides a stable network structure for small molecule liquid crystals. The application of PDLC strongly depends on the composition, morphology, size, properties of the phase interface, particle size control and matching of the properties of the two phases.

In the absence of an external voltage, a regular electric field cannot be formed between the PDLC films, the optical axis orientation of the liquid crystal molecules is random and disordered, its effective refractive index does not match the refractive index of the polymer, the incident light is strongly scattered, and the PDLC film is opaque or translucent; after applying an external voltage, the optical axis of the liquid crystal molecules is arranged perpendicular to the surface of the film, that is, consistent with the direction of the electric field, the effective refractive index of the liquid crystal molecules is basically matched with the refractive index of the polymer, there is no obvious interface, and a basically uniform medium is formed. The incident light is basically not scattered, and the PDLC film is transparent. Therefore, under the action of an external electric field, the PDLC film has optical switching characteristics. Specifically, the PDLC film can be used as smart glass. Through the induction of light and/or heat by the polymer material, it can form a shielding property under voltage drive, thereby achieving the purpose of controlling the room temperature, and at the same time has the effect of energy saving and environmental protection. This type of PDLC film is widely used in automotive window films, curtains, screens and other products.

Since liquid crystal molecules have optical anisotropy and dielectric anisotropy, PDLC films have significant optical properties. The indicators for measuring their photoelectric performance include: driving voltage, response time, transmittance, etc. The above performances are significantly dependent on factors such as the selected materials, preparation methods and processes. In addition, the structure and application properties of PDLC films are also subject to process conditions. Slight differences in process conditions may have a significant impact on the degree of phase separation, phase separation speed, two-phase structure and morphology, and phase interface structure and properties, which in turn affect the driving voltage, response time, haze, viewing angle, transmittance and other parameters of the PDLC film.

The existing PDLC products still have much to be improved in terms of reliability. Under long-term high temperature and sunlight environment, they are prone to increased power consumption, yellowing, and deterioration of optical switch characteristics. In addition, under high temperature environment (especially above 60°C), the off-state haze may deteriorate, the shielding property may be lost, and the optical switch characteristics may be lost.

Summary of the invention

In order to solve the technical problems existing in the prior art, the present invention provides a wide temperature liquid crystal composition, a wide temperature polymer dispersed liquid crystal composition and a wide temperature polymer dispersed liquid crystal film, which have the advantages of low driving voltage, fast response, good optical performance, high reliability, and a wide operating temperature range, thereby solving the problems of poor reliability and narrow operating temperature range of PDLC products in the prior art.

One of the objects of the present invention is to provide a wide temperature liquid crystal composition of a polymer dispersed liquid crystal, the composition comprising component A and component B, the component A comprising a compound represented by formula I-1 and/or I-2, and the component B comprising any one compound or a combination of at least two compounds of formula II-1, II-2 or II-3;

wherein R ₁ , R ₂ , R ₃ , R ₅ and R ₇ are each independently a C1-C10 chain alkyl or alkoxy group; Ring A, Ring B, Ring C, Ring D, Ring E, Ring F, Ring G, Ring H and Ring I are each independently a 1,4-cyclohexylene group, a 1,4-phenylene group, a group in which at least one -CH ₂ - in a 1,4-cyclohexylene group is replaced by -O-, a group in which at least one carbon-carbon single bond in a 1,4-cyclohexylene group is replaced by a carbon-carbon double bond, a group in which at least one -H in a 1,4-phenylene group is replaced by -CN, -F or -Cl, or a group in which at least one -CH＝ in a 1,4-phenylene group is replaced by -N＝; Z ₁ , Z ₂ , Z ₃ , Z ₄ , Z ₅ or Z ₆ are each independently a single bond or -COO-; X ₁ to X ₄ and Y ₁ to Y _{6 are} each independently -H or -F; R ₄ , R ₆ and R ₈ are independently halogen, haloalkyl or haloalkoxy containing 1-5 carbon atoms, haloalkenyl or haloalkenyloxy containing 2-5 carbon atoms. Preferably, R ₄ , R ₆ and R ₈ are independently any one of -F, -CF ₃ or -OCF ₃ .

In the present invention, the combination of liquid crystal molecules in component A and component B makes the liquid crystal composition have large dielectric anisotropy, high clearing point, large refractive index anisotropy, good low-temperature storage performance, and good miscibility with high-molecular UV polymers.

As a preferred technical solution of the present invention, the wide temperature liquid crystal composition has a clearing point greater than or equal to 100° C. and a refractive index greater than or equal to 0.18.

In the present invention, the above-mentioned limitation on the wide temperature liquid crystal composition can make the film have a wide operating temperature range, good optical properties and excellent contrast.

Preferably, the composition comprises 50-90wt% of component A and 10-50wt% of component B, preferably 55-85wt% of component A and 15-45wt% of component B, and further preferably 60-85wt% of component A and 15-40wt% of component B.

Among them, the mass fraction of component A can be 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, 85wt% or 90wt%, etc., and the mass fraction of component B can be 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt% or 50wt%, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

In the present invention, when the content of component A is lower than 50% or the content of component B is higher than 50%, the dielectric anisotropy of the liquid crystal composition is relatively small, resulting in a higher driving voltage.

As a preferred technical solution of the present invention, the compound represented by formula I-1 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-1 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-1-2 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-1-3 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-1-4 is selected from any one or a combination of at least two of the following compounds:

Wherein R ₁ ' is a C1-C10 chain alkyl group.

Preferably, the compound represented by formula I-1-5 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-1 is preferably any one or a combination of at least two of the compounds of formula I-1-1-1, I-1-4-1, I-1-4-2, I-1-5-1 or I-1-2-1. Typical but non-limiting examples of the combination include: a combination of CPN and CGN, a combination of CEPN and PEGN, a combination of CPN, CGN and PPN, a combination of CPN, CGN, PPN and OPPN, a combination of CGN, PPN, OPPN, PEPN and CEPN, a combination of CPN, PPN, OPPN, PEPN and CEPN, a combination of CPN, CGN, PPN, PEGN, PEUN and CEUN, a combination of CPN, CGN, PPN, OPPN, PEPN, CEPN, PEGN, PEUN, CEUN, CUN and DUN, etc.

Preferably, the compound represented by formula I-2 is selected from any one or a combination of at least two of the following compounds:

Said _X5 and _X6 are independently -H or -F, and at most one of _X5 and _X6 is -F.

Preferably, the compound represented by formula I-2-1 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-2-2 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-2-3 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-2-4 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-2-5 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-2-6 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-2-7 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula I-2 is preferably any one or a combination of at least two of the compounds of formula I-2-2-1, I-2-3-1, I-2-4-1, I-2-2-2, I-2-7-2, I-2-6-2 or I-2-3-2. Typical but non-limiting examples of the combination include: a combination of CPPN and PPPN, a combination of PPPN and CEPPN, a combination of CCEPN, CCEGN and CPEGN, a combination of CPPN, PPPN, CEPPN and CCEPN, a combination of CCUN, CPUN, PEPPN, CEPPN and PGPN, a combination of CPPN, PPPN, CEPPN, CCEPN, CCEGN and NPGP, a combination of CPPN, PPPN, CEPPN, NPGP, CPGN, CPEGN, CCEGN and PGPN, etc.

As a preferred technical solution of the present invention, the compound represented by formula II-1 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-1-1 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-1-2 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-1-3 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-1-4 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-1 is preferably any one or a combination of at least two of the compounds represented by general formula II-1-1-1 or general formula II-1-3-3;

Preferably, the compound represented by formula II-2 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-2-1 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-2-2 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-2-3 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-2-4 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-2-5 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-2-6 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-2-7 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-2 is preferably any one or a combination of at least two of the compounds of formula II-2-1-4, formula II-2-3-4, formula II-2-5-1, formula II-2-5-3 or formula II-2-5-4. Typical but non-limiting examples of the combination include: a combination of CCGF and CCUF, a combination of CPUF and PPUF, a combination of PGUF, PGPF and CPGF, a combination of CCEGF, CPEGF, CCPOCF3 and CPPOCF3, a combination of CCUF, CPUF, PGUF, PPUF and PGPF, a combination of CCEUF, CPEUF, CCEPF, CPEPF, CDUF and DPUF, etc.

Preferably, the compound represented by formula II-3 is selected from any one or a combination of at least two of the following compounds:

The Y ₇ to Y ₁₀ are each independently -H or -F.

Preferably, the compound represented by formula II-3-1 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-3-2 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-3-3 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-3-4 is selected from any one or a combination of at least two of the following compounds:

Preferably, the compound represented by formula II-3 is preferably any one or a combination of at least two of the compounds of formula II-3-1-3, formula II-3-1-4 or formula II-3-3-3. Typical but non-limiting examples of the combination include: a combination of CCPUF and CCPGF, a combination of CCGUF and CPGUF, a combination of CDPUF and DPGUF, a combination of CCPUF, CCPGF and CCGUF, a combination of CCPUF, CCGUF and CPGUF, a combination of CCPUF, CCPGF, CDPUF and DPGUF, a combination of CCPUF, CCPGF, CCGUF, CPGUF, CDPUF and DPGUF, a combination of CCPUF, CCPGF, CCGUF, CPGUF, CDPUF and DPGUF, and the like.

As a preferred technical solution of the present invention, the wide temperature liquid crystal composition comprises a compound shown in Formula III:

Wherein, R ₉ and R ₁₀ are each independently a C1-C10 straight-chain alkyl or alkoxy group, J and K are each independently a 1,4-cyclohexylene group or a 1,4-phenylene group, Y ₁₁ and Y ₁₂ are each independently -H or -F, a is 0 or 1, and if a is 1, J and K are not both 1,4-phenylene groups.

Preferably, the compound represented by formula III is selected from any one or a combination of at least two of the following compounds:

Among them, typical but non-limiting examples of the combination include: a combination of CPPC and PGPC, a combination of CPGP and CGPC, a combination of CGPC and PGP, a combination of CPPC, PGPC and CPGP, a combination of CPGP, CGPC, PGP, and CPP, a combination of CPPC, PGPC, CPGP, CGPC and PGP, or a combination of CPPC, PGPC, CPGP, CGPC, PGP and CPP, etc.

Preferably, the mass fraction of the compound represented by formula III in the wide temperature liquid crystal composition is 0 to 20wt%, such as 0wt%, 1wt%, 2wt%, 5wt%, 8wt%, 10wt%, 12wt%, 15wt%, 18wt% or 20wt%, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

In the present invention, the addition of the compound represented by formula III can increase the clearing point of the liquid crystal composition, and at the same time, the low-temperature storage performance of the liquid crystal composition is better.

Preferably, the wide temperature liquid crystal composition comprises a compound represented by formula IV:

wherein R ₁₁ is H, a substituted or unsubstituted C1-C10 chain alkyl group, a substituted or unsubstituted C3-C5 cycloalkyl group, or a group in which one or two or more non-adjacent -CH ₂ - in the substituted or unsubstituted C1-C10 chain alkyl group are independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and the substituent is -F or -Cl;

Ring L and ring M are each independently A group in which at least one -CH ₂ - is replaced by -O- or A group in which at least one carbon-carbon single bond is replaced by a carbon-carbon double bond A group in which at least one -H is replaced by -CN, -F or -Cl; or At least one -CH＝ in the group is replaced by -N＝;

Z ₇ represents any one of a single bond, -CH ₂ CH ₂ -, -CF ₂ CF ₂ -, -CF ₂ O-, -OCF ₂ -, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH-, -C≡C-, -CF=CF-, -CH ₂ O- or -OCH ₂ -;

b represents 0, 1, 2 or 3. When b=2 or 3, each ring L is the same or different, and each Z ₇ is the same or different;

X is any one of halogen, C1-C5 haloalkyl, C1-C5 haloalkoxy, C2-C5 haloalkenyl or C2-C5 haloalkenyloxy.

Preferably, the halogen is any one of F, Cl, Br or I.

Preferably, the compound represented by formula IV is selected from any one or a combination of at least two of the following compounds:

Typical but non-limiting examples of the combinations include: the combination of PUQUF and PGUQUF, the combination of PGUQUF and PGUQPOCF3, the combination of PGUQPOCF3 and CCQUF, the combination of PUQUF and CCQUF, the combination of PUQUF, PGUQUF and PGUQPOCF3, the combination of PGUQUF, PGUQPOCF3 and CCQUF, or the combination of PUQUF, PGUQUF, PGUQPOCF3 and CCQUF, etc.

Preferably, the mass fraction of the compound represented by formula IV in the wide temperature liquid crystal composition is 0 to 15wt%, such as 0wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt% or 15wt%, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

In the present invention, the addition of the compound represented by Formula IV can increase the dielectric anisotropy of the liquid crystal composition and reduce the driving voltage.

In the present invention, the C1-C10 straight-chain or branched-chain alkyl group may be methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, 3-hexyl, n-heptyl, 2-heptyl, n-octyl, 2-octyl, n-nonyl or n-decyl, etc.; the concept of the C1-C10 alkoxy group is similar to the concept of the C1-C10 straight-chain or branched-chain alkyl group, that is, the C1-C10 straight-chain or branched-chain alkyl group is connected to the main body of the compound through an oxygen atom; the concept of the C1-C10 straight-chain or branched-chain alkylene group is similar to the concept of the C1-C10 straight-chain or branched-chain alkyl group, that is, the C1-C10 straight-chain or branched-chain alkyl group has another free end connected to other groups.

In the present invention, C1-C5 haloalkyl means C1-C5 straight or branched alkyl with at least one hydrogen atom replaced by a halogen atom; C1-C5 haloalkoxy means C1-C5 straight or branched alkoxy with at least one hydrogen atom replaced by a halogen atom; C2-C5 haloalkenyl means C2-C5 alkenyl with at least one hydrogen atom replaced by a halogen atom; C2-C5 haloalkenyloxy means C2-C5 alkenyloxy with at least one hydrogen atom replaced by a halogen atom. Among them, the concepts of C1-C5 straight or branched alkyl and C1-C5 straight or branched alkoxy are the same as those of C1-C10 straight or branched alkyl, which are not described here. C2-C5 haloalkenyl and C2-C5 haloalkenyloxy means C1-C5 straight or branched alkyl and C1-C5 straight or branched alkoxy with α carbon and β carbon connected by a carbon-carbon double bond.

The second object of the present invention is to provide a wide temperature range polymer dispersed liquid crystal composition, which contains 15-70 wt % of the above wide temperature range liquid crystal composition and 30-85 wt % of a high molecular weight UV polymer.

Among them, the mass fraction of the wide temperature liquid crystal combination can be 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt% or 70wt%, etc., and the mass fraction of the high molecular UV polymer can be 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, 75wt%, 80wt% or 85wt%, etc., but are not limited to the listed values, and other values not listed within the above numerical ranges are equally applicable.

Preferably, the present invention adopts UV polymerization to perform polymerization, and the wide temperature polymer dispersed liquid crystal composition contains 40-60 wt % of the wide temperature liquid crystal composition and 40-60 wt % of the high molecular UV polymer.

As a preferred technical solution of the present invention, the high molecular UV polymer contains 20-80wt% prepolymer, 20-80wt% active diluent and 1-6wt% photoinitiator, wherein the mass fraction of the prepolymer can be 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt% or 80wt%, etc., the mass fraction of the active diluent can be 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt% or 80wt%, etc., the mass fraction of the photoinitiator can be 1wt%, 2wt%, 3wt%, 4wt%, 5wt% or 6wt%, etc., but is not limited to the listed values, and other values not listed within the above numerical ranges are equally applicable.

Preferably, the prepolymer comprises any one of polyurethane acrylate, epoxy acrylate, acrylic prepolymer, polyester acrylate, polyether acrylate, polybutadiene acrylate or polyamide, or a combination of at least two thereof. Typical but non-limiting examples of the combination include: a combination of polyurethane acrylate and epoxy acrylate, a combination of epoxy acrylate and acrylic prepolymer, a combination of acrylic prepolymer and polyester acrylate, a combination of polyester acrylate and polyether acrylate, a combination of polyether acrylate and polybutadiene acrylate, a combination of polybutadiene acrylate and polyamide, or a combination of polyurethane acrylate, epoxy acrylate and acrylic prepolymer, etc.

Preferably, the reactive diluent is any one of hydroxyethyl methacrylate, 4-hydroxybutyl acrylate, 2-hydroxypropyl methacrylate, ethyl methacrylate, n-octyl methacrylate, 2-dodecyl acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, isobornyl acrylate, isobornyl methacrylate, hydroxydicyclopentene or N-acryloylmorpholine, or a combination of at least two thereof. Typical but non-limiting examples of the combination include: a combination of hydroxyethyl methacrylate and 4-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxypropyl methacrylate, ethyl methacrylate, n-octyl methacrylate, 2-dodecyl acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, isobornyl acrylate, isobornyl methacrylate, hydroxydicyclopentene or N-acryloylmorpholine. A combination of acrylate and 2-hydroxypropyl methacrylate, a combination of 2-hydroxypropyl methacrylate and ethyl methacrylate, a combination of n-octyl methacrylate and 2-dodecyl acrylate, a combination of 2-dodecyl acrylate and 1,6-hexanediol diacrylate, a combination of trimethylolpropane triacrylate and isobornyl acrylate, a combination of isobornyl methacrylate and hydroxydicyclopentene, a combination of hydroxydicyclopentene and N-acryloylmorpholine, a combination of hydroxyethyl methacrylate, 4-hydroxybutyl acrylate and 2-hydroxypropyl methacrylate, and the like.

Preferably, the photoinitiator is any one of 1-hydroxycyclohexyl phenyl ketone, (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholine-1-propanone or 2-isopropylthioxanthone, or a combination of at least two thereof. Typical but non-limiting examples of the combination include: a combination of 1-hydroxycyclohexyl phenyl ketone and (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide, (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide, A combination of phenylphosphine oxide and 2-methyl-1-(4-methylthiophenyl)-2-morpholine-1-propanone, a combination of 2-methyl-1-(4-methylthiophenyl)-2-morpholine-1-propanone and 2-isopropylthioxanthone, a combination of 1-hydroxycyclohexylphenyl ketone and 2-isopropylthioxanthone, or a combination of 1-hydroxycyclohexylphenyl ketone, (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide and 2-methyl-1-(4-methylthiophenyl)-2-morpholine-1-propanone, etc.

As a preferred technical solution of the present invention, the wide temperature polymer dispersed liquid crystal composition contains 0.1 to 5wt% of the dye, such as 0.1wt%, 0.2wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt% and 5wt%, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

The third object of the present invention is to provide a wide temperature range polymer dispersed liquid crystal film, the liquid crystal film comprising two conductive films and a liquid crystal layer located between the conductive films, the liquid crystal layer comprising the wide temperature range polymer dispersed liquid crystal composition described in any one of claims 6-8 and spacer particles.

As a preferred technical solution of the present invention, the conductive film is a PET-ITO conductive film.

Preferably, the thickness of the conductive film is 0.060 mm to 0.180 mm, any one of 0.060 mm, 0.070 mm, 0.080 mm, 0.100 mm, 0.120 mm, 0.150 mm or 0.180 mm, or a combination of at least two thereof, but not limited to the listed values, and other values not listed within the range are also applicable.

Preferably, the mass ratio of the wide temperature polymer dispersed liquid crystal composition to the spacer particles is 1:0.0002-0.005, such as 1:0.0002, 1:0.0005, 1:0.001, 1:0.002, 1:0.003, 1:0.004 or 1:0.005, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

Preferably, the particle size of the spacer particles is 10-30μm, such as 10μm, 12μm, 15μm, 18μm, 20μm, 22μm, 25μm, 28μm or 30μm, but is not limited to the listed values. Other unlisted values within the numerical range are also applicable, preferably 10 to 20μm.

Preferably, the thickness of the liquid crystal layer is 10 to 20 μm, such as 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

In the present invention, the specific meanings of the codes in each liquid crystal molecule are shown in Table 1.

Table 1

Compared with the prior art, the present invention has at least the following beneficial effects:

(1) The present invention provides a wide temperature liquid crystal composition having a high clearing point (Cp ≥ 100°C), a large refractive index anisotropy (Δn ≥ 0.18), and a large dielectric anisotropy; and the wide temperature liquid crystal composition has good solubility in polymers;

(2) The present invention provides a wide temperature range polymer dispersed liquid crystal composition having the characteristics of low homogeneous phase temperature, fast polymerization speed, moderate viscosity, etc.;

(3) The present invention provides a wide temperature range polymer dispersed liquid crystal film, which has the advantages of low driving voltage, fast response, good optical performance, high reliability, wide operating temperature range, and good weather resistance, thereby solving the problems of poor reliability and narrow operating temperature range of PDLC products in the prior art.

DETAILED DESCRIPTION

For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

Take the following compound as an example to explain its structure code:

If the structural formula is represented by the codes shown in Table 1, it can be expressed as nCPPm, where n represents the number of carbon atoms of the left-end alkyl group, for example, n is 3, which means that the alkyl group is -C ₃ H ₇ , where C represents cyclohexyl, P represents phenyl, and m represents the number of carbon atoms of the right-end alkyl group, for example, m is 2, which means that the alkyl group is -C ₂ H ₅ .

In the following examples, the abbreviated codes for the performance test items are shown in Table 2.

Table 2 Abbreviation codes for performance test items

Test project code meaning Δn: Optical anisotropy (589nm, 25℃) Δε: Dielectric anisotropy (1KHz, 25℃) Cp: Clearing point (nematic-isotropic phase transition temperature, °C) LTS Low temperature stability

Each component used in the liquid crystal composition of the following embodiments can be synthesized by a known method or obtained through commercial channels. The components of the obtained liquid crystal composition are tested to meet the standards of electronic compounds.

The liquid crystal compositions in the following examples are prepared according to the proportions of the components (the brackets at the end of the components in each example are the general formulas of the components) and are mixed by conventional preparation methods such as heating, ultrasound, suspension, etc. to obtain the liquid crystal compositions.

The compositions of the wide temperature liquid crystal compositions used in the specific embodiments of the present invention are shown in Tables 3-5.

Table 3

Table 4

Liquid crystal B Mass fraction/% 3CCEPC3 2 Cp 117 5CCEPC5 2 △n 0.184 2CEPPN 4 ∆ε 13.0 3CEPPN 4 LTS -40℃ 3CCEGN 4 3CPPN 3 3CGN 7 5CPGN 5 3CCUF 6 5CCUF 7 3CCPUF 3 2CCPUF 2 4CCPUF 3 2PPN 3 3PPN 5 4PPN 4 5PPN 8 2OPPN 4 3OPPN 6 5OPPN 6 NPGP3 12

Table 5

The compositions of the high molecular weight UV polymers in the specific embodiments of the present invention are shown in Tables 6 and 7.

Table 6

Table 7

MM8209, MM8610 and MPB110 in Table 6 and Table 7 are prepolymers produced by Shanghai Feikai Optoelectronic Materials Co., Ltd.

Example 1

Material model Mass Liquid crystal materials Liquid crystal A 55 polymer High molecular weight UV polymer 1 45 Spacer particles 20μm 0.5

Example 2

Material model Mass Liquid crystal materials Liquid crystal A 50 polymer High molecular weight UV polymer 2 50 Spacer particles 20μm 0.5

Example 3

Material model Mass Liquid crystal materials Liquid crystal B 55 polymer High molecular weight UV polymer 1 45 Spacer particles 20μm 0.5

Example 4

Material model Mass Liquid crystal materials Liquid crystal B 55 polymer High molecular weight UV polymer 2 45 Spacer particles 20μm 0.5

Example 5

Material model Mass Liquid crystal materials Liquid crystal C 60 polymer High molecular weight UV polymer 1 40 Spacer particles 20μm 0.5

Example 6

Material model Mass Liquid crystal materials Liquid crystal C 60 polymer High molecular weight UV polymer 2 40 Spacer particles 20μm 0.5

The above Examples 1-6 were weighed according to the mass ratio in the table and stirred at room temperature for 30 minutes to make them fully stirred. The mixed mixture was evenly coated between two pieces of ITO-PET and irradiated with 365nm ultraviolet light and 5mW/ ^cm2 light intensity at 25-35℃ for 5 minutes to obtain a 220mm×180mm polymer dispersed liquid crystal film.

The photoelectric performance test of Examples 1-6 was conducted using a WGT-S light transmittance/haze tester produced by Shanghai Shenguang Instrument Co., Ltd. The off-state optical data was measured when PDLC was applied with 0V, and the on-state optical data was measured when PDLC was applied with a corresponding driving voltage. The test results are shown in Tables 8 and 9.

Table 8

Table 9

It can be seen from the above test data that the PDLC film prepared according to Examples 1-6 has large off-state haze, good shielding properties, small on-state haze, good transparency, and low driving voltage. In a high temperature environment of 80°C, the haze changes little, the shielding performance is good, and it can meet the use requirements in high temperature environments such as vehicles and outdoors. At the same time, the optical properties change little after high temperature aging and sunlight aging, and have good weather resistance.

The applicant declares that the present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims (17)

1. A wide-temperature polymer-dispersed liquid crystal composition, characterized in that the wide-temperature polymer-dispersed liquid crystal composition contains 50 to 60 wt% of the wide-temperature liquid crystal composition and 40 to 50 wt% of a high-molecular UV polymer, and the The wide-temperature liquid crystal composition includes component A and component B, where component A includes compounds represented by formulas I-1 and I-2, and component B includes any one of formulas II-2 or II-3. Compound or a combination of at least two compounds, the component B includes at least one compound represented by formula II-2; The compound represented by formula I-1 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula I-1 includes at least one compound of formula I-1-4-2 The compound represented by the formula I-2 is selected from any one or a combination of at least two of the following compounds: The compound represented by the formula I-2 includes at least one compound of the formula I-2-4 and at least one compound of the formula I-2-6; Among them, R ₁ , R ₂ , R ₅ and R ₇ are each independently a C1 to C10 chain alkyl group or alkoxy group, and ring E, ring F, ring G, ring H and ring I are each independently 1,4. -At least one -CH ₂ in cyclohexylene, 1,4-phenylene, 1,4-cyclohexylene -a group substituted by -O- or at least one carbon-carbon single bond in 1,4-cyclohexylene A group substituted by a carbon-carbon double bond or a group in which at least one -H of the 1,4-phenylene group is substituted by -CN, -F or -Cl, or a group in which at least one -CH of the 1,4-phenylene group is substituted by -N=substituted group, Z ₅ or Z ₆ are independently a single bond or -COO-, X ₁ to X ₄ and Y ₃ to Y ₆ are independently -H or -F, X ₅ and X ₆ are each independently -H or -F, and at most one of X ₅ and X ₆ is -F, and R ₆ and R ₈ are each independently -F; R ₁ ' is C1～C10 chain alkyl group; The composition includes 60 to 85 wt% of component A and 15 to 40 wt% of component B; The clearing point of the wide-temperature liquid crystal composition is greater than or equal to 100°C, and the refractive index anisotropy is greater than or equal to 0.18. 2. The wide-temperature polymer dispersion liquid crystal composition according to claim 1, characterized in that the compound represented by the formula I-1-1 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula I-1-4 is also selected from any one or a combination of at least two of the following compounds: 3. The wide-temperature polymer dispersion liquid crystal composition according to claim 1, characterized in that the compound represented by the formula I-2-2 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula I-2-3 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula I-2-4 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula I-2-6 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula I-2-7 is selected from any one or a combination of at least two of the following compounds: 4. The wide temperature polymer dispersion liquid crystal composition according to claim 1, characterized in that the compound represented by formula II-2 is selected from any one or a combination of at least two of the following compounds: Among them, Y ₇ is -H or -F. 5. The wide-temperature polymer dispersion liquid crystal composition according to claim 4, characterized in that the compound represented by formula II-2-1 is selected from any one or a combination of at least two of the following compounds: The compound represented by the formula II-2-2 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula II-2-3 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula II-2-4 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula II-2-5 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula II-2-6 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula II-2-7 is selected from any one or a combination of at least two of the following compounds: 6. The wide temperature polymer dispersion liquid crystal composition according to claim 1, characterized in that the compound represented by formula II-3 is selected from any one or a combination of at least two of the following compounds: The Y ₈ to Y ₁₀ are each independently -H or -F. 7. The wide temperature polymer dispersion liquid crystal composition according to claim 6, characterized in that the compound represented by formula II-3-1 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula II-3-2 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula II-3-3 is selected from any one or a combination of at least two of the following compounds: The compound represented by formula II-3-4 is selected from any one or a combination of at least two of the following compounds: 8. The wide-temperature polymer-dispersed liquid crystal composition according to claim 1, characterized in that the wide-temperature liquid crystal composition includes a compound represented by Formula III: Among them, R ₉ and R ₁₀ are independently C1-C10 chain alkyl or alkoxy, ring J and ring K are independently 1,4-cyclohexylene or 1,4-phenylene, Y ₁₁ and Y ₁₂ are independently -H or -F, and a is 0 or 1. If a is 1, then J and K are not 1,4-phenylene at the same time. 9. The wide-temperature polymer dispersion liquid crystal composition according to claim 8, characterized in that the compound represented by formula III is selected from any one or a combination of at least two of the following compounds: 10. The wide-temperature polymer-dispersed liquid crystal composition according to claim 8, wherein the mass fraction of the compound represented by Formula III in the wide-temperature liquid crystal composition is 0 to 20 wt%. 11. The wide-temperature polymer dispersion liquid crystal composition according to claim 1, characterized in that the wide-temperature liquid crystal composition includes a compound represented by formula IV, and the compound represented by formula IV is selected from the following compounds Any one or a combination of at least two: in, R ₁₁ is one of H, a substituted or unsubstituted C1 to C10 chain alkyl group, a substituted or unsubstituted C3 to C5 cycloalkyl group, or the substituted or unsubstituted C1 to C10 chain alkyl group. Or two or more non-adjacent -CH ₂ - are independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO- group, the substituent is -F or -Cl. 12. The wide-temperature polymer-dispersed liquid crystal composition according to claim 11, wherein the mass fraction of the compound represented by formula IV in the wide-temperature liquid crystal composition is 0 to 15 wt%. 13. The wide-temperature polymer dispersion liquid crystal composition according to claim 1, characterized in that the high molecular UV polymer contains 20-80wt% prepolymer, 20-80wt% reactive diluent and 1-6wt% Photoinitiator. 14. The wide temperature polymer dispersion liquid crystal composition according to claim 13, wherein the prepolymer includes polyurethane acrylate, epoxy acrylate, acrylic acid prepolymer, polyester acrylate, polyether acrylate Any one or a combination of at least two of ester, polybutadiene acrylate or polyamide; The reactive diluent is hydroxyethyl methacrylate, 4-hydroxybutyl acrylate, 2-hydroxypropyl methacrylate, ethyl methacrylate, n-octyl methacrylate, and 2-dodecyl acrylate. Any one of ester, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, isobornyl acrylate, isobornyl methacrylate, hydroxydicyclopentene or N-acryloylmorpholine or a combination of at least two; The photoinitiator is 1-hydroxycyclohexyl phenyl ketone, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 2-methyl-1-(4-methylthiobenzene) base)-2-morpholine-1-propanone or any one or a combination of at least two of 2-isopropylthiaxanthone. 15. The wide-temperature polymer-dispersed liquid crystal composition according to claim 14, wherein the wide-temperature polymer-dispersed liquid crystal composition contains 0.1 to 5 wt% of dye. 16. A wide-temperature polymer-dispersed liquid crystal film, characterized in that the liquid crystal film includes two conductive films and a liquid crystal layer located between the conductive films, and the liquid crystal layer includes the liquid crystal film according to any one of claims 1 to 15. The wide-temperature polymer-dispersed liquid crystal composition and spacer particles are provided. 17. The liquid crystal film according to claim 16, wherein the conductive film is a PET-ITO conductive film; The thickness of the conductive film is 0.060mm～0.180mm; The mass ratio of the wide-temperature polymer-dispersed liquid crystal composition and spacer particles is 1:0.0002-0.005; The thickness of the liquid crystal layer is 10-20 μm; The particle size of the spacer particles is 10-30 μm.