Liquid crystal composition, phase difference film, laminated body and preparation method of laminated body

Abstract

The invention relates to the technical field of liquid crystal materials and optical thin films, and provides a liquid crystal composition, a phase difference film, a laminated body and a preparation method of the laminated body. The liquid crystal composition comprises a first polymerizable liquid crystal compound and a reactive monomer, the first polymerizable liquid crystal compound has reverse wavelength dispersibility, and the reactive monomer contains an acrylate group and an isocyanate group. The problems of energy consumption, environmental pollution and poor tolerance in the bonding process of the phase difference film taking the liquid crystal composition as the raw material at present are solved, and the adverse effects of a bonding layer on the optical performance and the service life of the phase difference film are effectively avoided.

Description

Technical Field

[0001] The present application relates to the technical field of liquid crystal materials and optical films, and in particular to a liquid crystal composition, a phase difference film, a laminate and a preparation method thereof. Background Art

[0002] Optical film is a key component in modern display technology. It can affect the display quality, such as display brightness, clarity, and large viewing angle color deviation. Among them, the reverse wavelength dispersion phase difference film is widely used in the polarizer of liquid crystal display (LCD) and organic light emitting diode display (OLED) for anti-reflection and viewing angle compensation due to its unique optical properties. Reverse wavelength dispersion usually refers to the proportional relationship between the phase difference and the wavelength at the normal viewing angle, usually expressed by the phase difference R450 at a wavelength of 450nm and the phase difference R550 at a wavelength of 550nm satisfying the following conditions: R450 / R550≤1.0.

[0003] The phase difference film that achieves reverse wavelength dispersion currently mainly uses liquid crystal polymer materials, which use the birefringence of the material to cause phase difference. Mainstream, these liquid crystal polymers usually use prepolymer coating liquid as a precursor, and the precursor contains liquid crystal monomers with polymerizable groups, initiators, solvents, etc. In order for the liquid crystal to obtain a certain orientation, there should also be a functional alignment layer on the substrate it carries. After the precursor solution is coated on the substrate containing the alignment layer, it goes through a heating and drying step, and after the solvent evaporates, the liquid crystal compound forms a liquid crystal phase with a specific orientation (ie, "alignment") under certain temperature conditions. Subsequently, the polymerization reaction is initiated by ultraviolet light to fix the alignment of the liquid crystal, thereby obtaining an anisotropic polymer film with a regular orientation, which then has the optical properties of a phase difference film.

[0004] The bonding of the two interfaces of the phase difference film and the polarizer requires the action of an adhesive. The more commonly used adhesives in display devices are UV-curing adhesives, pressure-sensitive adhesives, and heat-sensitive adhesives. Although UV-curing adhesives have the characteristics of short processing time and environmental protection, they require a high degree of compatibility with the phase difference film and require a large amount of energy. Pressure-sensitive adhesives can be used immediately without excessive energy consumption, but they are easily affected by temperature and humidity, which can shorten their service life. Thermally conductive adhesives need to consider the impact of temperature on the phase difference film, and can easily destroy the long-term tolerance of the phase difference film. Liquid crystal compositions, as raw materials for phase difference films, will also affect the performance of the phase difference film, resulting in energy consumption, environmental pollution, and poor tolerance during the bonding process. Summary of the invention The invention discloses a liquid crystal composition, a phase difference film, a laminate and a preparation method thereof, so as to solve the problems of energy consumption, environmental pollution and poor tolerance in the bonding process of the phase difference film using the liquid crystal composition as a raw material.

[0005] To achieve the above object, the embodiments of this specification adopt the following technical solutions: In a first aspect, an embodiment of the present application provides a liquid crystal composition, including a first polymerizable liquid crystal compound and a reactive monomer. Among them, the first polymerizable liquid crystal compound is a first polymerizable liquid crystal compound having reverse wavelength dispersion, and the reactive monomer contains an acrylate group and an isocyanate group; The structure of the first polymerizable liquid crystal compound satisfies the general formula (M-1): (M-1); Wherein, L 1 ~L 4 Each independently selected from , , , , Or ; H 1 ~H 2 , Z 1 ~Z 2 Each independently selected from , , , , , Or ; J 1 ~J 2 Each independently selected from , , Or a single bond; Y 1 ~Y 2 Each independently selected from an alkyl chain , where n is an integer, n = 2~20, and the alkyl chain of Y 1 ~Y 4 Has the same or different n values; R 1 ~R 2 Each independently selected from , , , Or ; B 0 Selected from Or , where m is an integer, m = 1-20; D 1 Selected from N or C atoms, D 2 Selected from S or O atoms; R 0 selected from a hydrogen atom, a methyl group, an ethyl group, a methoxy group, , , , , group.

[0006] Optionally, the liquid crystal composition includes: 20 to 99 parts by weight of a first polymerizable liquid crystal compound and 0.5 to 16 parts by weight of a reactive monomer.

[0007] Optionally, the structure of the reactive monomer satisfies the general formula (M-2): (M-2) Ad 1 ~Ad 2 each independently selected from an isocyanate group, a hydroxyl group, a trimethylsilyl group; Ln 1 ~Ln 4 each independently selected from an alkyl chain or an alkoxy chain having 0 to 10 carbon atoms; R 3 、R 4 each independently selected from , , , or group.

[0008] Optionally, the liquid crystal composition further includes a second polymerizable liquid crystal compound, wherein the second polymerizable liquid crystal compound is a second polymerizable liquid crystal compound having positive wavelength dispersion.

[0009] In a second aspect, an embodiment of the present application provides a retardation film, which is polymerized from the above liquid crystal composition.

[0010] In a third aspect, an embodiment of the present application provides a laminate, which includes the above retardation film, an aqueous binder, and a substrate, the aqueous binder is disposed on the substrate, and the retardation film is disposed on the aqueous binder.

[0011] Optionally, the raw materials of the aqueous binder include a silane coupling agent and a reactive monomer.

[0012] Optionally, the silane coupling agent is selected from one or a combination of more than one of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, vinyltriethoxysilane, isocyanatopropyltriethoxysilane, chloropropyltriethoxysilane, chloropropyltrimethoxysilane, octadecyltrimethoxysilane, octyltriethoxysilane, bis-[3-(triethoxysilyl)propyl]tetrasulfide, bisaminosilane, anilinomethyltrimethoxysilane, and ureidosilane.

[0013] Optionally, the structure of the reactive monomer satisfies the general formula (M-2): (M-2) Ad 1 ~Ad 2 Each independently selected from an isocyanate group, a hydroxyl group, and a trimethylsilyl group; Ln 1 ~Ln 4 Each independently selected from an alkyl chain or an alkoxy chain having C0 to C10; R 3 、R 4 Each independently selected from 、 、 、 or groups.

[0014] Fourthly, an embodiment of the present application provides a method for preparing a laminate, including the following steps: coating an aqueous binder on the above-mentioned retardation film, and then laying a substrate flat on the surface of the aqueous binder, and drying to obtain the laminate.

[0015] The above at least one technical solution adopted in the embodiment of the present application can achieve the following beneficial effects: The present application provides a reactive liquid crystal composition: a liquid crystal containing a reactive group, a reactive monomer; wherein, the liquid crystal and the monomer can increase the crosslinking density of the retardation film and form a dense network structure. In addition, the liquid crystal containing multiple reactive groups will increase the viscosity of the system and enhance the coating uniformity; the reactive monomer will also provide reaction sites with the silane coupling agent in the aqueous adhesive, enhancing the adhesion to the aqueous adhesive. The present application effectively solves the problems of the bonding stability, the tolerance, and the environmental friendliness of the retardation film made of a liquid crystal composition in existing display devices. Description of the Drawings

[0016] The accompanying drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings: Figure 1 It is a schematic structural diagram of an OLED anti-reflection circular polarizing plate structure provided for an embodiment of this specification; Figure 2 It is a schematic structural diagram of a retardation film structure for Sunglass free provided for an embodiment of this specification. Detailed implementation manners

[0017] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below in conjunction with the specific embodiments of the present application and the corresponding accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0018] According to an embodiment of the present application, a liquid crystal composition is provided, which includes a first polymerizable liquid crystal compound and a reactive monomer. Among them, the first polymerizable liquid crystal compound is a first polymerizable liquid crystal compound having inverse wavelength dispersion, and the reactive monomer contains an acrylate group and an isocyanate group.

[0019] In the embodiments of this specification, the liquid crystal composition includes: 20 to 99 parts by weight of the first polymerizable liquid crystal compound, and 0.5 to 16 parts by weight of the reactive monomer.

[0020] In the embodiments of this specification, the structure of the first polymerizable liquid crystal compound satisfies the general formula (M-1): (M-1); Wherein, L 1 ~ L 4 Each independently selects from , , , , or ; H 1 ~ H 2 , Z 1 ~ Z 2 Each independently selects from , , , , , or ; J 1 ~J 2 are each independently selected from , , or a single bond; Y 1 ~Y 2 are each independently selected from an alkyl chain , where n is an integer, n = 2 to 20, and the value of n in the alkyl chain of Y 1 ~Y 4 is the same or different; R 1 ~R 2 are each independently selected from , , , or ; B 0 is selected from or , where m is an integer, m = 1 - 20; D 1 is selected from N or a C atom, and D 2 is selected from an S or an O atom; R 0 is selected from a hydrogen atom, a methyl group, an ethyl group, a methoxy group, , , , , groups.

[0021] In the examples of this specification, the general formula (M-1) of the first polymerizable liquid crystal compound, preferably, L 1 ~L 4 are each independently selected from , , or . Preferably, H 1 ~H 2 are each independently selected from , or . Preferably, J 1 ~J 2 are each independently selected from , , , . Preferably, Y 1 ~Y 2 are each independently selected from an alkyl chain , where n is an integer, n = 4 to 8, and Y1 ~Y 4 The value of n in the alkyl chain of is the same or different. Preferably, R 1 ~R 2 are each independently selected from , . Preferably, B 2 is selected from or , where m is an integer and m = 3 to 5. Preferably, R 0 is selected from a hydrogen atom or .

[0022] The general formula (M-1) of the first polymerizable liquid crystal compound is selected from the following structures:

[0023] In the examples of this specification, the reactive monomer is a monomer containing an acrylate group and an isocyanate NCO group, or a monomer containing an acrylate group and a trimethoxysilyl group. The structure of the reactive monomer satisfies the general formula (M-2): (M-2) Ad 1 ~Ad 2 is a bonding strength enhancing group, and can be independently selected from an isocyanate group, a hydroxyl group, and a trimethylsilyl group; Ln 1 ~Ln 4 can be independently an alkyl chain or an alkoxy chain with C0 to C10; R 3 , R 4 are each independently selected from , , , or groups; Meanwhile, when Ln 2 , Ln 4 is selected as a H atom, Ad 2 , R 4 is not bonded.

[0024] The general formula (M-2) of the reactive monomer is selected from the following structures:

[0025] In the embodiments of the present specification, the liquid crystal composition further includes a second polymerizable liquid crystal compound, wherein the second polymerizable liquid crystal compound is a second polymerizable liquid crystal compound having positive wavelength dispersion. The structure of the second polymerizable liquid crystal compound satisfies the general formula (M-3). These second polymerizable liquid crystal compounds exhibit positive wavelength dispersion and are blended with reverse wavelength dispersion monomers to regulate wavelength dispersion, increase crosslinking density, adjust refractive index, induce chiral phase, reduce cost, etc. The weight part of the second polymerizable liquid crystal compound is 1 to 80 parts.

[0026] The general formula (M-3) of the second polymerizable liquid crystal compound is selected from the following structures:

[0027] There can be various types of the first polymerizable liquid crystal compound conforming to the general formula (M-1) as a component of the liquid crystal composition; there can be various types of the second polymerizable liquid crystal compound conforming to the general formula (M-2) as a component of the liquid crystal composition.

[0028] In order to form a crosslinked network by photoinitiated polymerization, a photoinitiator generally needs to be added to the components of the liquid crystal composition. The photoinitiators applicable to the present invention may include, but are not limited to, the compounds represented by the following structures of Formula I-1 to I-7. At the same time, some brand photoinitiators such as BASF OXE-03, OXE-04, etc. can be added.

[0029]

[0030] In the components of the liquid crystal composition of the present invention, the weight part of the photoinitiator is 0.2 to 10 parts, preferably 3 to 7 parts.

[0031] In the actual coating production process, other additives can be added as needed to ensure solution stability, leveling property, photo-crosslinking efficiency, etc. For example, the additives applicable to the components of the liquid crystal composition of the present invention may include one or more combinations of leveling and defoaming additives, polymerization inhibitors, and chain transfer agents. Among them, the leveling and defoaming additives can be at least one of BYK-300, BYK-306, BYK-358, BYK-354, BYK-515, BYK-3560, BYK-3566 purchased from BYK Company; MEGAFACE F-554, F-556 purchased from DIC Company; and Zonyl FS-520, Zonyl 8857A purchased from DuPont Company. The polymerization inhibitors suitable for the present invention may include at least one of benzoquinone, hydroquinone, 2,6-di-tert-butyl-4-methylphenol (BHT); the chain transfer agents suitable for the present invention may include at least one of dodecyl mercaptan and triethylamine.

[0032] In the components of the liquid crystal composition of the present invention, the weight portion of the auxiliary agent is 0.01 to 5 parts, preferably 0.1 to 1 part.

[0033] In the actual production process of optical films using the components of the liquid crystal composition, solvents are needed to assist in coating processing. The solvents suitable for the components of the liquid crystal composition of the present invention mainly include benzene, ketones, esters and high polarity solvents. Benzene solvents mainly include: toluene, xylene, chlorobenzene, ethylbenzene; ketone solvents mainly include: butanone, 3-pentanone, cyclopentanone, cyclohexanone, N-methylpyrrolidone, isophorone; ester solvents mainly include: ethyl acetate, butyl acetate, propylene glycol methyl ether acetate; high polarity solvents mainly include: n-butanol, isopropanol, propylene glycol methyl ether, N,N-dimethylformamide, ethanolamine, acetonitrile. In one embodiment, one solvent can be used. In another embodiment, the above solvents can be used in combination. Among them, in terms of weight parts (and calculated by non-volatile content), 100 to 1200 parts by weight of solvent can be added to the components of the above-mentioned liquid crystal composition, preferably 250 to 350 parts by weight of solvent.

[0034] According to one embodiment of the present application, a phase difference film is provided, wherein the phase difference film is polymerized from the above liquid crystal composition, and the phase retardation R450 of the phase difference film at a wavelength of 450 nm and the phase retardation R550 at a wavelength of 550 nm satisfy the following condition: R450 / R550≤1.0.

[0035] According to one embodiment of the present application, a laminate is provided, comprising the above-mentioned phase difference film, an aqueous adhesive and a substrate, wherein the aqueous adhesive is disposed on the substrate, and the phase difference film is disposed on the aqueous adhesive.

[0036] In the embodiments of this specification, the raw materials of the water-based adhesive include a silane coupling agent and a reactive monomer.

[0037] In the embodiments of this specification, the reactive monomer is a monomer containing an acrylate group and an isocyanate NCO group, or a monomer containing an acrylate group and a trimethoxysilane group. The structure of the reactive monomer satisfies the general formula (M-2): (M-2) Ad 1 ~Ad 2 As the adhesion enhancing group, isocyanate group, hydroxyl group and trimethylsilyl group can be selected independently; Ln 1 ~Ln 4 It can be a C0~C10 alkyl chain or alkoxy chain alone; R 3 , R4 Each independently selected from 、 、 、 or group; Meanwhile, when Ln 2 、Ln 4 is selected as H atom, it is not bonded to Ad 2 、R 4 .

[0038] The general formula of the reactive monomer (M-2) is selected from the following structures:

[0039] Adding a silane coupling agent to the raw materials of the water-based binder to achieve bonding through osmosis and chemical bonding with the phase difference film. The water-based binder can also be called a water glue binder, and here "water glue" is defined as an adhesive with water as the main solvent. It usually consists of a water-soluble polymer cross-linking agent and a catalyst. The silane coupling agent includes one or a combination of more than one of the following types: KH-550 (γ-aminopropyltriethoxysilane) KH-560 (γ-(2,3-epoxypropoxy)propyltrimethoxysilane) KH-570 (γ-methacryloxypropyltrimethoxysilane) KH-792 (N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane) A-151 (vinyltriethoxysilane) Y-9030 (isocyanatopropyltriethoxysilane) KH-540 (chloropropyltriethoxysilane) Z-6376 (chloropropyltrimethoxysilane) KBM-3103 (octadecyltrimethoxysilane) Dynasylan OTS (octyltriethoxysilane) Si-69 (bis-[3-(triethoxysilyl)propyl]tetrasulfide) A-1289 (bisaminosilane) Z-6075 (anilinomethyltrimethoxysilane) KBM-602 (ureidosilane).

[0040] In the embodiments of the present specification, the substrate is a resin film substrate. Based on the integrity of the lamination structure, a resin film substrate is usually laminated on the polarizer. Among them, the resin film substrate may include any one of a polyethylene film, a polypropylene film, a polyvinyl chloride film, a polyester film, a cellulose film, and a polyolefin film. The cellulose film may include a cellulose acetate resin film. The thickness of the resin film substrate may be 10 μm - 100 μm, so as to reduce the occupied space and thus save the internal space of the liquid crystal display panel.

[0041] According to an embodiment of the present application, a method for preparing a laminate is provided, including the following steps: coating an aqueous binder on the above-mentioned retardation film, and then laying the substrate flat on the surface of the aqueous binder, and drying to obtain the laminate.

[0042] In the embodiments of the present specification, before coating the aqueous binder on the retardation film, it further includes: pre-treating the retardation film, specifically, it may be corona treatment. Specifically, the cleaned retardation film is treated by a corona device according to preset treatment parameters. The preset treatment parameters are: the retardation film moves at a speed of 6 m / min in the corona device, the treatment power is 1 - 2 kw, and the treatment time is 1 - 3 min. In the case where the preset treatment includes corona treatment, a retardation film with a water contact angle of 0° - 48° can be obtained.

[0043] In the embodiments of the present specification, before laying the substrate flat on the surface of the aqueous binder, it further includes: the substrate needs to be cleaned before use, specifically, the resin film substrate can be cleaned by an ion blower. By cleaning the film, foreign matters, dust, etc. on the film surface can be removed, thereby avoiding the influence of foreign matters, dust, etc. on the liquid crystal performance.

[0044] In the embodiments of the present application, any one or more of pickling treatment, alkali washing treatment, ultraviolet treatment, and plasma treatment can be used to treat the surface of the resin film substrate, as long as the water contact angle of the treated resin film substrate is 0° - 28°.

[0045] In one embodiment, in the case where the preset treatment includes alkali washing treatment, the preset treatment of the surface of the resin film substrate includes: cleaning the resin film substrate by an ion blower; alkali washing the cleaned resin film substrate in an alkaline solution with a solid content of 10% for 5 min - 15 min; cleaning the resin film substrate with deionized water for 5 min - 10 min; drying the resin film substrate in an oven at 70°C - 110°C. It can be understood that in the case where the preset treatment includes pickling treatment, a retardation film with a water contact angle of 0° - 28° can be obtained by the above preparation method.

[0046] The technical solutions provided by the embodiments of the present application are described in detail below.

[0047] Example 1: A method for preparing a liquid crystal composition is provided, including the steps of: weighing M-1-3, M-2-1, M-3-2, OXE-03, and BYK-354 according to the corresponding weight part ratios, mixing them, and adding toluene and cyclohexanone in corresponding mass parts, stirring and dissolving completely at 60 °C, and cooling to room temperature for standby. The methods used in the following examples are the same. The weight part ratios of the liquid crystal composition are as follows:

[0048] Example 2: The weight part ratios of the liquid crystal composition are as follows:

[0049] Example 3: The weight part ratios of the liquid crystal composition are as follows:

[0050] Example 4: The weight part ratios of the liquid crystal composition are as follows:

[0051] Comparative Example 1: The weight part ratios of the liquid crystal composition are as follows:

[0052] Comparative Example 2: The weight part ratios of the liquid crystal composition are as follows:

[0053] Comparative Example 3: The weight part ratios of the liquid crystal composition are as follows:

[0054] Comparative Example 4: The weight part ratios of the liquid crystal composition are as follows:

[0055] Comparative Example 5: The weight part ratios of the liquid crystal composition are as follows:

[0056] Comparative Example 6: The weight part ratios of the liquid crystal composition are as follows:

[0057] Example 5: A method for preparing a retardation film is provided: Prepare a cellulose triacetate film of A4 size, and use bar coating to uniformly coat the surface of the film with the photo-alignment agent HSPA-156B (manufactured by Osaka Organic Co., Ltd.) (10 / 15μm Bar, 30mm / s). Subsequently, dry at 120°C. After cooling to room temperature, irradiate the surface with polarized ultraviolet light of 313nm at 10mJ to obtain a film substrate with an alignment layer.

[0058] On the film substrate with an alignment layer, use bar coating to uniformly coat the liquid crystal compositions of Examples 1 to 4 and Comparative Examples 1 to 6 respectively (10 / 15μm Bar, 30mm / s), and dry to volatilize the solvent. The drying temperature is slightly lower than the clearing point temperature of the liquid crystal mixture. Subsequently, cool to room temperature, and irradiate the surface of the film with the composition using a mercury lamp in a nitrogen atmosphere, with a total energy of 1500mJ / cm 2 , thus obtaining the retardation film.

[0059] Example 6: A method for preparing an aqueous adhesive is provided. Weigh M-2-9 (silane coupling agent), Z200 (Mitsubishi Chemical, Gosenex ™Z series), SPM01 (Mitsubishi Chemical, Safelink™), and deionized water according to the corresponding weight ratio, mix them, and stir and dissolve completely at 95°C, then cool to room temperature for standby. The weight ratio of the raw materials of the aqueous adhesive is as follows:

[0060] Comparative Example 7: The weight ratio of the raw materials of the aqueous adhesive is as follows:

[0061] Comparative Example 8: The weight ratio of the raw materials of the aqueous adhesive is as follows:

[0062] Comparative Example 9: The weight ratio of the raw materials of the aqueous adhesive is as follows:

[0063] Comparative Example 10: The weight ratio of the raw materials of the aqueous adhesive is as follows:

[0064] Comparative Example 11: The weight parts ratio of the raw materials of the water-based adhesive is as follows:

[0065] Comparative Example 12: The weight parts ratio of the raw materials of the water-based adhesive is as follows:

[0066] Example 7: Provide a method for preparing a laminate. The retardation film obtained in Example 5 is subjected to corona treatment. The treatment power is set to 2 kw and the speed is 6 m / min to obtain the corona-treated retardation film; the water-based adhesive prepared in Example 6 is coated on the retardation film by means of bar coating (10 / 15 μ, 30 mm / s); the film resin substrate after alkali washing treatment is laid flat on the surface of the water-based adhesive; it is placed in an oven at 85 °C for curing and drying for 5 min to obtain the laminate.

[0067] Example 8: Testing method Retardation film water contact angle test: For the retardation film after corona treatment (obtained in Example 1), take three points on the left, middle, and right respectively, and use an SDC-200PRO double automatic injection contact angle measuring instrument to conduct a water contact angle test. Drop deionized water droplets on the flat test surface, and take a picture and fit to obtain the water contact angle at this site. After the three-point test is completed, take the average value to obtain the water contact angle of the retardation film.

[0068] Adhesion test of the water-based adhesive in the laminate: The peel strength test of the bonding structure is used to reflect the magnitude of its adhesion. The specific method is to use a KJ-1065 series computerized peel strength testing machine. Stick a 3M tape vertically on the steel plate, cut a retardation film of the same size as the 3M tape, clamp the bottom with a steel clip, and peel it in a 180° peeling manner to obtain the peel curve and peel force value of the laminate.

[0069] Test results

[0070] The water contact angle represents the spreadability on the retardation film (the smaller the value, the easier the water glue spreads on the retardation film); the peel force represents the bonding strength (the larger the value, the greater the strength of the bonding structure).

[0071] After testing, the water contact angles of the phase difference films obtained for Nos. 1-7 were 45-48°. After being laminated with the laminate, they could not be peeled off by 3M tape. This indicates that the proportion of the liquid crystal matrix has little effect on the contact and bonding properties of the phase difference film. The results obtained for Nos. 8-10 can show that the M2 structure of the liquid crystal composition can significantly change the wetting effect and bonding strength of the phase difference film. Nos. 11-16 illustrate that the structure and content of the coupling agent in the aqueous adhesive have a significant impact on the connection effect between the phase difference film and the laminate, and tend to show an active group structure the same as or similar to that of the liquid crystal composition, so that there can be a chemical bond between the phase difference film and the laminate, which can further enhance the interlayer adhesion between the phase difference film and the polarizer.

[0072] Example 9: Based on the phase difference films and the aqueous adhesive in Nos. 1-16, they can be used in circular polarizers or phase difference film structures in displays, such as OLED antireflection circular polarizers, LCD compensation films, phase difference films for sunglass free, etc.

[0073] The structure of the OLED antireflection circular polarizer using the phase difference film in this application is as Figure 1 shown. Figure 1 At least one of the phase difference film 1 and the phase difference film 2 uses the liquid crystal phase difference film in this application.

[0074] The structure of the phase difference film for sunglass free using the phase difference film in this application is as Figure 2 shown. Figure 2 The display using the sunglass free phase difference film in it can be an LCD screen or an OLED screen.

[0075] This application can be used in the system of the phase difference film and the inner laminate of the polarizer. Due to the environmental protection and energy-saving characteristics of the water-based adhesive bonding, it will greatly protect the optical and use properties of the phase difference film, and at the same time achieve a strong bonding effect at the interface, improving the technical problems of bonding energy consumption and poor tolerance of the phase difference film caused by easy pollution in existing display devices.

[0076] The positive / negative dispersion liquid crystals contained in the examples of this application all contain reactive groups such as carboxyl groups, hydroxyl groups, and ester bonds in the liquid crystals. These groups not only provide alignment force for the liquid crystals, but also provide more reaction sites to react with monomers to increase the crosslinking degree. Reactive monomers containing functional groups such as acrylate and isocyanate, these functional groups can not only react with the liquid crystals, but also bond with the coupling agent in the aqueous adhesive to enhance the bonding effect.

[0077] In the embodiment of the present application, the liquid crystal composition is dissolved in a solvent and then coated on the surface of a substrate. After drying and curing, a retardation film with R450 / R550 ≤ 1.0 is obtained. The surface treatment methods mainly include corona treatment and plasma treatment, which are used to further improve the surface activity of the retardation film, thereby enhancing the bonding effect with the aqueous adhesive.

[0078] In the embodiment of the present application, the solid component is heated and stirred to dissolve in deionized water. After it is completely dissolved, a viscous liquid is formed, and an aqueous adhesive is obtained after cooling. The enhancement methods mainly include adding reactive monomers such as acrylate and isocyanate and silane coupling agents to the aqueous adhesive, and realizing bonding through penetration and chemical bonding with the retardation film.

[0079] The treatment methods in the embodiment of the present application mainly include pickling, alkali washing treatment, etc. The substrate is contacted, soaked, cleaned, dried, etc. This method is used to clean foreign matters on the surface of the substrate, increase the surface energy of the substrate, and thus enhance the bonding with the retardation film.

[0080] The present application provides reactive monomers, which can increase the crosslinking density of the retardation film and form a dense network structure. The reactive monomers also provide reaction sites with the silane coupling agent in the water-based adhesive layer, enhancing the bonding force with the water-based adhesive layer. In addition to enhancing the dispersion of the solid components in the water-based adhesive, the silane coupling agent in the water-based adhesive can form a "weak interface layer" between the retardation film and the silane coupling agent through infiltration and bonding, etc., effectively bonding with the retardation film. Therefore, alignment defects of the retardation film caused by pollution and the like in the later processing can be avoided. The present application effectively solves problems such as the bonding stability of the retardation film, the tolerance of the retardation film, and environmental friendliness in existing display devices.

[0081] The present application provides a reactive liquid crystal composition, which comprises a liquid crystal with reactive groups and a reactive monomer. Among them, the liquid crystal and the monomer can increase the crosslinking density of the retardation film and form a dense network structure. In addition, the liquid crystal containing multiple reactive groups will increase the viscosity of the system and enhance the coating uniformity; the reactive monomer will also provide reaction sites for the silane coupling agent in the aqueous adhesive, enhancing the bonding force with the aqueous adhesive. The aqueous adhesive of the present application contains groups such as hydroxyl groups, which can provide partial binding force through hydrogen bonding and other interactions. In addition to enhancing the dispersibility of the solid components in the water-based glue, the silane coupling agent will form a "weak interface layer" between the retardation film and the silane coupling agent through wetting and bonding, etc., effectively bonding with the retardation film. Therefore, alignment defects of the retardation film caused by contamination and the like during later processing can be avoided. The present application provides a surface treatment, which can reduce the surface tension, increase the contact and wetting effects between the retardation film and the substrate, and make them fit more closely. The present application provides an aqueous adhesive. In addition to protecting the optical, mechanical and service performance of the retardation film from being damaged, this bonding method can be used only after drying, with simple operation and convenient production. In addition, it does not require ultraviolet light energy and thermal energy, greatly saving energy and reducing consumption; there is no solvent volatilization during the production process. It effectively solves the problems of the bonding stability of the retardation film, the tolerance of the retardation film and environmental protection in existing display devices.

[0082] The present application enhances the interfacial bonding performance with the aqueous adhesive by optimizing the composition of the liquid crystal composition and the surface treatment process, and is applicable to the fields of liquid crystal display and optical devices. The present application adopts an aqueous adhesive to realize the preparation method for bonding the retardation film and the polarizer. It can not only reduce the loss of light energy or thermal energy, but also does not contain the volatilization of organic substances, and has good environmental protection. In addition, it will not affect the retardation film during use, thereby improving its tolerance and service life.

[0083] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, commodity or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of another identical element in the process, method, commodity or device comprising the said element.

[0084] The above are only the embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A liquid crystal composition, characterized in that: It comprises a first polymerizable liquid crystal compound and a reactive monomer, wherein the first polymerizable liquid crystal compound is a first polymerizable liquid crystal compound with reverse wavelength dispersion, and the reactive monomer contains an acrylate group and an isocyanate group; The structure of the first polymerizable liquid crystal compound satisfies the general formula (M-1): （M-1）； Wherein, L1~L4 are each independently selected from , , , , or ; H1~H2, Z1~Z2 are each independently selected from , , , , , or ; J1~J2 are each independently selected from , , or single key; Y1~Y2 are each independently selected from an alkyl chain , wherein n is an integer, n=2~20, and the values ​​of n in the alkyl chains of Y1~Y4 are the same or different; R1~R2 are each independently selected from , , , or ; B0 is selected from or , where m is an integer, m=1-20; D1 is selected from N or C atoms, D2 is selected from S or O atoms; R0 is selected from hydrogen atom, methyl, ethyl, methoxy, , , , , Group.

2. The liquid crystal composition according to claim 1, characterized in that: The liquid crystal composition comprises: 20 to 99 parts by weight of a first polymerizable liquid crystal compound and 0.5 to 16 parts by weight of a reactive monomer.

3. The liquid crystal composition according to claim 1, characterized in that: The structure of the reactive monomer satisfies the general formula (M-2): （M-2） Ad1~Ad2 are each independently selected from isocyanate, hydroxyl, and trimethylsilyl; Ln1~Ln4 are each independently selected from a C0~C10 alkyl chain or alkoxy chain; R3 and R4 are each independently selected from , , , or Group.

4. The liquid crystal composition according to claim 1, characterized in that: The liquid crystal composition further includes a second polymerizable liquid crystal compound, wherein the second polymerizable liquid crystal compound is a second polymerizable liquid crystal compound having positive wavelength dispersion.

5. A phase difference film, characterized in that: The phase difference film is formed by polymerizing the liquid crystal composition described in any one of claims 1 to 4.

6. A laminated body, characterized in that: The laminated body comprises the phase difference film according to claim 5, an aqueous adhesive, and a substrate, the aqueous adhesive is provided on the substrate, and the phase difference film is provided on the aqueous adhesive.

7. The laminate according to claim 6, characterized in that The raw materials of the water-based adhesive include a silane coupling agent and a reactive monomer.

8. The laminate according to claim 7, characterized in that The silane coupling agent is selected from the group consisting of one or more combinations of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, vinyltriethoxysilane, isocyanatepropyltriethoxysilane, chloropropyltriethoxysilane, chloropropyltrimethoxysilane, octadecyltrimethoxysilane, octyltriethoxysilane, bis-[3-(triethoxysilyl)propyl]tetrasulfide, bisaminosilane, anilinemethyltrimethoxysilane, and ureasilane.

9. The laminate according to claim 7, characterized in that The structure of the reactive monomer satisfies the general formula (M-2): （M-2） Ad1~Ad2 are each independently selected from isocyanate, hydroxyl, and trimethylsilyl; Ln1~Ln4 are each independently selected from a C0~C10 alkyl chain or alkoxy chain; R3 and R4 are each independently selected from , , , or Group.

10. A method for preparing a laminate, characterized in that: The following steps are involved: The aqueous adhesive is coated on the phase difference film according to claim 5, and then the substrate is laid flat on the surface of the aqueous adhesive and dried to obtain a laminate.

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