A dye PDLC material composition and a PDLC dimming film

Abstract

This application relates to the technical field of dimming films, and specifically discloses a dye PDLC material composition and a PDLC dimming film. The dye PDLC material composition comprises the following components: 40-70 wt% of a liquid crystal composition; 0.1-8 wt% of an anthraquinone dichroic dye; 10-50 wt% of an active diluent; 5-30 wt% of a prepolymer; 0.02-3 wt% of a photoinitiator; 0-5 wt% of a light stabilizer; 0.1-0.9 wt% of spacer particles; 0-15 wt% of a chiral agent; The on-state haze of the PDLC dimming film is less than 5%, and the off-state haze is greater than 90%; The full-light dimming range is 16-55%. The PDLC dimming film of this application has a relatively high full-light dimming range, with a low on-state haze and a high off-state haze. The dimming film can be gray, or can be personalized single colors such as red, yellow, blue, green, etc., meeting the requirements for visual appearance in buildings, automobiles, high-speed rails, airplanes, etc.

Description

Technical Field

[0001] The present application relates to the technical field of dimming films, and more specifically, to a dye PDLC material composition and a PDLC dimming film. Background Art

[0002] Polymer dispersed liquid crystal (PDLC), as a new type of liquid crystal functional film material, can be arbitrarily switched between a transparent state and a scattering state (fog state) through the regulation of an electric field, and can meet the privacy protection requirements while dimming, so it is widely used in indoor partitions, bathrooms and other application scenarios. However, due to the narrow viewing angle of PDLC, narrow full-light dimming range (10% - 15%), and white or milky white color, its application scenarios are very limited. It cannot meet the customer's needs when used in applications with higher aesthetic requirements such as buildings, automobiles, high-speed rails and airplanes.

[0003] Dichroic dye is a dye that shows different colors due to different light absorptions along the long axis and short axis of the dye molecule. Based on the above properties of dichroic dyes, in order to improve the full-light dimming range of PDLC dimming films and endow PDLC dimming film products with diverse colors, in related technologies, dichroic dyes are added to PDLC materials to achieve this. However, a dye PDLC with high performance (on-state haze less than 5%; off-state haze greater than 90%) has not been successfully prepared, thus limiting its application. Analyzing the reasons, it may be that the dichroic dye fades during the PDLC polymerization process, and its light absorption affects the polymerization separation effect, resulting in a decrease in the off-state haze. Therefore, it is of great significance to develop a dye PDLC with a wide full-light dimming range and high performance. Summary of the Invention

[0004] In order to improve the full-light dimming range of PDLC dimming films and make them have a lower on-state haze and a higher off-state haze, the present application provides a dye PDLC material composition and a PDLC dimming film.

[0005] In the first aspect, the present application provides a dye PDLC material composition, adopting the following technical solution:

[0006] A dye PDLC material composition, calculated by weight percentage, includes the following components:

[0007] Liquid crystal composition 40 - 70 wt%;

[0008] Anthraquinone dichroic dye 0.1 - 8 wt%;

[0009] Reactive diluent 10 - 50 wt%;

[0010] Prepolymer 5 - 30 wt%;

[0011] Photoinitiator: 0.02 to 3 wt%;

[0012] Light stabilizer: 0 to 5 wt%;

[0013] Spacer particles: 0.1 to 0.9 wt%;

[0014] Chiral agent: 0 to 15 wt%;

[0015] The PDLC dimming film prepared from the dye PDLC material composition has an on-state haze of 1.5 to 5% and an off-state haze of 90 to 95.5%; the full light dimming range is 16 to 55%.

[0016] Preferably, the anthraquinone dichroic dye is one or more of the compounds represented by the following formulas (I-1) to (I-12);

[0017]

[0018]

[0019] Wherein, A1, A2, H1, H2, H3 and H4 are each independently selected from the following structures:

[0020]

[0021] X1 and X2 are each independently selected from: -C≡C, -COO, -O-, single bond, -CH2O-, -CF2O-, -OCO-, -OCH2-, -CH=CH-, -CF=CF-, -CF2-CF2- or -(CH2)

[0020] , , n , , , , n ,

[0023] ,

[0022] ,

[0021] , -, n is an even number from 2 to 10;

[0022] Z1 and Z2 are each independently selected from: -C≡C, -COO-, -O-, single bond, -CH2O-, -COS-, -CF2O-, -OCO-, -OCH2-, -CH=CH-, -CF=CF-, -CF2-CF2-, -CH(CH3)2N-, -N(CH3)- or -(CH2) n -, n is an even number from 2 to 10;

[0023] R1 and R2 are each independently selected from: C1-C20 linear alkyl, halogenated C1-C20 linear alkyl, cyanated C1-C20 linear alkyl, -CF3, -OCF3, -C(CH3)3, -CN, -H, -F, -Cl or -NCS; it can also be selected from: the structure in which one or more non-adjacent -CH2- in C1-C20 linear alkyl are each independently replaced by -O-, -COO, -OCO-, -COS-, -SCO-, -C=C-, CF=CF- or -C≡C-.

[0024] It should be noted that the above dichroic dyes can be used alone or in combination of multiple types, and can be selected according to the colors required for actual products.

[0025] Preferably, it includes 0.3-5 wt% of dichroic dye.

[0026] Preferably, the clearing point of the liquid crystal composition > 70 °C, the melting point < -20 °C, the optical anisotropy is 0.12-0.3, the dielectric anisotropy > 5, and the rotational viscosity at 20 °C < 150 cP.

[0027] More preferably, the clearing point of the liquid crystal composition > 90 °C;

[0028] Even more preferably, the clearing point of the liquid crystal composition > 100 °C.

[0029] More preferably, the melting point < -30 °C;

[0030] Even more preferably, the melting point < -40 °C.

[0031] More preferably, the optical anisotropy is 0.15-0.28.

[0032] More preferably, the rotational viscosity at 20 °C < 120 cP;

[0033] Even more preferably, the rotational viscosity at 20 °C < 100 cP.

[0034] The liquid crystal composition can be prepared by oneself or purchased as a commercially available product, but it should meet the above requirements.

[0035] Preferably, the prepolymer is one or more of polyurethane acrylate, epoxy acrylate, acrylic prepolymer, polyester acrylate, polyether acrylate, polybutadiene acrylate, and polyamide.

[0036] Preferably, the reactive diluent is one or more of 2-hydroxyethyl methacrylate, 1,4-butanediol diacrylate, 4-hydroxybutyl acrylate, 2-hydroxypropyl methacrylate, ethyl methacrylate, n-octyl methacrylate, dodecyl acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, isobornyl acrylate, isobornyl methacrylate, hydroxybicyclopentene, bicyclopentenyl acrylate, and N-acryloylmorpholine.

[0037] Preferably, the photoinitiator is one or more of 1-hydroxycyclohexyl phenyl ketone, (2,4,6-trimethylbenzoyl) diphenylphosphine oxide, α,α-dimethoxy-α-phenylacetophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, and 2-isopropylthioxanthone.

[0038] More preferably, the photoinitiator is a mixture of two or more of 1-hydroxycyclohexyl phenyl ketone, (2,4,6-trimethylbenzoyl) diphenylphosphine oxide, α,α-dimethoxy-α-phenylacetophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholin-1-propanone, and 2-isopropylthioxanthone.

[0039] Preferably, the content of the photoinitiator is 0.05-3 wt%.

[0040] Preferably, the particle size of the spacer particles is 10-30 μm.

[0041] More preferably, the particle size of the spacer particles is 10-20 μm.

[0042] Preferably, the light stabilizer is one or more of the compounds represented by the following formulas (Ⅱ-1) to (Ⅱ-7);

[0043]

[0044]

[0045] Preferably, the chiral agent is one or more of the compounds represented by the following formulas (Ⅲ-1) to (Ⅲ-7);

[0046]

[0047] In a second aspect, the present application provides a PDLC dimming film, adopting the following technical solution:

[0048] A PDLC dimming film is prepared from the dye PDLC material composition as described above for the dye PDLC.

[0049] In summary, the present application has at least the following beneficial effects:

[0050] 1. By controlling the addition ratios of the liquid crystal composition, anthraquinone dichroic dye, reactive diluent, and prepolymer, the obtained dimming film has a high off-state haze and a low on-state haze.

[0051] 2. One or more of the compounds represented by the formulas (Ⅰ-1) to (Ⅰ-12) are selected as the dichroic dye. This dichroic dye has good compatibility with the PDLC system, is not easily precipitated or faded during the PDLC polymerization process. Therefore, the obtained PDLC dimming film has a high off-state haze; and the above dichroic dye absorbs part of the scattered light, thereby further reducing the on-state haze.

[0052] 3. Through the specific selection of anthraquinone dichroic dyes, the present application greatly improves the full-light dimming range of the dimming film, meeting the requirements for the dimming range of dimming films in this field.

[0053] 4. The dimming film of the present application can be made into gray or single colors such as red, yellow, blue, and green according to actual needs, meeting the requirements for visual appearance in buildings, automobiles, high-speed rails, airplanes, etc. Specific Embodiments

[0054] The present application will be further described in detail below with reference to examples and comparative examples.

[0055] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0056] Examples

[0057] Examples 1-5

[0058] A dye PDLC material composition, with its components and corresponding weight fractions shown in Table 1.

[0059]

[0060]

[0061] Table 1

[0062] Among them, the anthraquinone dichroic dyes in Examples 1-5 are all composed of the dyes of the following formulas (1)-(5) mixed in a weight ratio of 2.2:3.6:5.0:4.0:4.0;

[0063]

[0064] The clearing point of the liquid crystal composition (Beijing Boyue Shikong, JXLC40900) in Examples 1-3 is 97 °C, the melting point is -40 °C, the optical anisotropy is 0.269, the dielectric anisotropy is 12, and the rotational viscosity at 20 °C is 75 cP; the clearing point of the liquid crystal composition (Jiangsu Synthesis HTW109100-100) in Examples 4-5 is 112 °C, the melting point is -40 °C, the optical anisotropy is 0.252, the dielectric anisotropy is 27.5, and the rotational viscosity at 20 °C is 89 cP.

[0065] The reactive diluent is composed of a mixture of 2-hydroxyethyl methacrylate, isobornyl methacrylate, 1,4-butanediol diacrylate, and isooctyl acrylate. Among them, in Example 1, the content of 2-hydroxyethyl methacrylate is 2.5 wt%, and the content of isobornyl methacrylate is 20 wt%; the content of 1,4-butanediol diacrylate is 2.5 wt%, and the content of isooctyl acrylate is 25 wt%. In Example 2, the content of 2-hydroxyethyl methacrylate is 1.7 wt%, and the content of isobornyl methacrylate is 17 wt%; the content of 1,4-butanediol diacrylate is 1.0 wt%, and the content of isooctyl acrylate is 13 wt%. In Example 3, the content of 2-hydroxyethyl methacrylate is 1.0 wt%, and the content of isobornyl methacrylate is 10 wt%; the content of 1,4-butanediol diacrylate is 0.5 wt%, and the content of isooctyl acrylate is 4.5 wt%. In Example 4, the content of 2-hydroxyethyl methacrylate is 1.88 wt%, and the content of isobornyl methacrylate is 8 wt%; the content of 1,4-butanediol diacrylate is 1.0 wt%, and the content of isooctyl acrylate is 8 wt%. In Example 5, the content of 2-hydroxyethyl methacrylate is 0.5 wt%, and the content of isobornyl methacrylate is 5 wt%; the content of 1,4-butanediol diacrylate is 0.4 wt%, and the content of isooctyl acrylate is 4.1 wt%.

[0066] The prepolymer is polyurethane acrylate; the particle size of the spacer particles is 20 nm (Nano Micro Technology); the photoinitiator is 1-hydroxycyclohexyl phenyl ketone;

[0067] The light stabilizer is The chiral agent is

[0068] In addition, in other embodiments, the anthraquinone dichroic dye can also be one or more of the compounds represented by the following formulas (I-1) to (I-12). When the anthraquinone dichroic dye is a mixture of two or more of the compounds represented by the formulas (I-1) to (I-12), the mixing ratio can be selected according to the actual required color.

[0069]

[0070]

[0071]

[0072]

[0073] Among them, A1, A2, H1, H2, H3, and H4 are each independently selected from the following structures:

[0074]

[0075] X1 and X2 are each independently selected from: -C≡C, -COO, -O-, single bond, -CH2O-, -CF2O-, -OCO-, -OCH2-, -CH=CH-, -CF=CF-, -CF2-CF2- or -(CH2) n -, where n is an even number from 2 to 10;

[0076] Z1 and Z2 are each independently selected from: -C≡C, -COO-, -O-, single bond, -CH2O-, -COS-, -CF2O-, -OCO-, -OCH2-, -CH=CH-, -CF=CF-, -CF2-CF2-, -CH(CH3)2N-, -N(CH3)- or -(CH2) n -, where n is an even number from 2 to 10;

[0077] R1 and R2 are each independently selected from: C1-C20 alkyl, halogenated C1-C20 alkyl, cyano C1-C20 alkyl, -CF3, -OCF3, -C(CH3)3, -CN, -H, -F, -Cl or -NCS; and may also be selected from: a structure in which one or more non-adjacent -CH2- in C1-C20 alkyl are each independently replaced by -O-, -COO, -OCO-, -COS-, -SCO-, -C=C-, CF=CF- or -C≡C-.[[ID=*** ]] [[ID=*** ]]

[0078] In other embodiments, the liquid crystal mixture only needs to satisfy a clearing point > 70 °C, a melting point < -20 °C, an optical anisotropy of 0.12 - 0.3, a dielectric anisotropy > 5, and a rotational viscosity at 20 °C < 150 cP. It can be prepared by oneself or purchased as a commercially available product.[[ID=*** ]] [[ID=*** ]]

[0079] In other embodiments, the reactive diluent can also be selected from one or more of hydroxyethyl methacrylate, 1,4-butanediol diacrylate, 4-hydroxybutyl acrylate, 2-hydroxypropyl methacrylate, ethyl methacrylate, n-octyl methacrylate, dodecyl acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, isobornyl acrylate, isobornyl methacrylate, hydroxy dicyclopentene, dicyclopentenyl acrylate, and N-acryloylmorpholine.[[ID=*** ]] [[ID=*** ]]

[0080] In other embodiments, the prepolymer can also be selected from one or more of polyurethane acrylate, epoxy acrylate, acrylic prepolymer, polyester acrylate, polyether acrylate, polybutadiene acrylate, and polyamide.[[ID=*** ]] [[ID=*** ]]

[0081] In other embodiments, the photoinitiator may also be selected from one or more of 1-hydroxycyclohexyl phenyl ketone, (2,4,6-trimethylbenzoyl) diphenyl phosphine oxide, α,α-dimethoxy-α-phenylacetophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholin-1-propanone, and 2-isopropylthioxanthone.

[0082] In other embodiments, the light stabilizer may also be one or more of the compounds represented by the following formulas (II-1) to (II-7).

[0083]

[0084]

[0085]

[0086] In other embodiments, the chiral agent may also be one or more of the compounds represented by the following formulas (III-1) to (III-7).

[0087]

[0088]

[0089]

[0090] In other embodiments, the particle size of the spacer particles can be arbitrarily selected within the range of 10 to 30 μm.

[0091] Comparative Example

[0092] Comparative Examples 1-4

[0093] A dye PDLC material composition, which is different from that of Example 2 in that the components and their corresponding weight parts are shown in Table 2.

[0094]

[0095] Table 2

[0096] Comparative Example 5

[0097] A dye PDLC material composition, which is different from that of Example 2 in that:

[0098] The dichroic dye is an azo dichroic dye, and the azo dichroic dye has the structure shown in the following formula (6):

[0099]

[0100] Application Example

[0101] Using the dye PDLC material composition in the above Examples 1-5 to prepare a PDLC dimming film, the preparation method is as follows: After uniformly mixing a dichroic dye and a liquid crystal composition, a mixture A is obtained; after uniformly mixing a reactive diluent and a prepolymer, a mixture B is obtained; after uniformly mixing the mixture A and the mixture B, a mixture C is obtained; after adding a photoinitiator, spacer particles, a light stabilizer, and a chiral agent to the mixture C, it is stirred evenly in the dark at room temperature (25°C) to obtain a dye PDLC material composition; the obtained dye PDLC material composition is uniformly coated between two transparent substrates with a conductive coating through a coating laminator, and after cutting and ultraviolet curing, a PDLC dimming film is obtained.

[0102] Performance detection test Test 1: Respectively take the dimming films prepared in Examples 1-5 and Comparative Examples 1-5 as test objects, cut the PDLC dimming films into sheets of 100*100 mm respectively, and conduct the switch-state haze test and total light transmittance test after power-on according to the method specified in GB / T 2410-2008. The power-on voltage is 48 V and the current is 2 A, and observe the appearance changes of the samples. The test results are recorded in Table 3 below.

[0103]

[0104]

[0105] Table 3

[0106] Test 2: Respectively take the dye PDLC material compositions of Examples 1-5 and Comparative Examples 1-5 as test objects, and uniformly coat the dye PDLC material composition between two transparent substrates with a conductive coating through a coating laminator, and after cutting (cut into 100*100 mm) and ultraviolet curing, a PDLC dimming film is obtained. Before ultraviolet curing, test the L ＊ , a ＊ , b ＊ values of the test sample, and record them as L0 ＊ , a0 ＊ , b0 ＊ respectively; after ultraviolet curing, test the L ＊ , a ＊ , b ＊ values of the test sample again, and record them as L1 ＊ , a1 ＊ , b1 ＊ respectively. Calculate the △L ＊ , △a ＊ , △b ＊ values:

[0107] △L ＊ = L0 ＊ - L1 ＊ ;

[0108] △a ＊ = a0 ＊ - a1 ＊ ;

[0109] △b ＊ = b0 ＊ - b1 ＊ ;

[0110] According to △L ＊ , △a ＊ , △b ＊ value, the total color difference △E:

[0111] △E = [(△L ＊ ) 2 + (△a ＊ ) 2 + (△b ＊ ) 2 1 / 2 ;

[0112] The test results are recorded in Table 4 below.

[0113]

[0114]

[0115] Table 4

[0116] (Note: Generally, when △E ≤ 2.0, the human eye cannot distinguish the color difference)

[0117] By analyzing the data in Table 3 and Table 4, it can be seen that compared with Examples 1-5, the on-state haze of the obtained dimming film in Comparative Examples 1-5 has increased, the off-state haze has decreased, the full-light dimming range has decreased significantly, and after ultraviolet curing, the total color difference change △E of the dimming film obtained in Comparative Examples 1-5 is significantly lower than the relevant values in Examples 1-5. This shows that the PDLC dimming film prepared in the examples of the present application has the advantages of high off-state haze, low on-state haze, wide full-light dimming range, and is not prone to fading.

[0118] This specific embodiment is only an explanation of the present application, and it does not limit the present application. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.​

Claims

1. A dye PDLC material composition, characterized in that, Comprising the following components by weight percentage: Liquid crystal composition 40 - 70 wt%; Anthraquinone dichroic dye 0.1 - 8 wt%; Reactive diluent 10 - 50 wt%; Prepolymer 5 - 30 wt%; Photoinitiator 0.02 - 3 wt%; Light stabilizer 0 - 5 wt%; Spacer particles 0.1 - 0.9 wt%; Chiral agent 0 - 15 wt%; The PDLC dimming film prepared from the dye PDLC material composition has an on-state haze of less than 5% and an off-state haze of more than 90%; the full light dimming range is 16 - 55%; The anthraquinone dichroic dye is composed of dyes of the following formulas (1) - (5) mixed in a weight ratio of 2.2:3.6:5.0:4.0:4.0; Formula (1); Formula (2); Formula (3); Formula (4); Formula (5).

2. The dye PDLC material composition according to claim 1, characterized in that The liquid crystal composition has a clearing point > 70 °C, a melting point < -20 °C, an optical anisotropy of 0.12 - 0.3, a dielectric anisotropy > 5, and a rotational viscosity at 20 °C < 150 cP.

3. The dye PDLC material composition according to claim 1, characterized in that, The prepolymer is one or more of polyurethane acrylate, epoxy acrylate, acrylic prepolymer, polyester acrylate, polyether acrylate, polybutadiene acrylate, and polyamide.

4. The dye PDLC material composition according to claim 1, characterized in that The reactive diluent is one or more of 2-hydroxyethyl methacrylate, 1,4-butanediol diacrylate, 4-hydroxybutyl acrylate, 2-hydroxypropyl methacrylate, ethyl methacrylate, n-octyl methacrylate, dodecyl acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, isobornyl acrylate, isobornyl methacrylate, hydroxy dicyclopentene, dicyclopentenyl acrylate, and N-acryloylmorpholine.

5. The dye PDLC material composition according to claim 1, characterized in that, The photoinitiator is one or more of 1-hydroxycyclohexyl phenyl ketone, (2,4,6-trimethylbenzoyl) diphenylphosphine oxide, α,α-dimethoxy-α-phenylacetophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholin-1-propanone, and 2-isopropylthioxanthone.

6. The dye PDLC material composition according to claim 1, characterized in that, The particle size of the spacer particles is 10 - 30 μm.

7. The dye PDLC material composition according to claim 1, characterized in that, The light stabilizer is one or more of the compounds represented by the following formulas (II-1) - (II-7); （Ⅱ-1）； （Ⅱ-2）； （Ⅱ-3）； （Ⅱ-4）； （Ⅱ-5）； （Ⅱ-6）； （Ⅱ-7）。 8. The dye PDLC material composition according to claim 1, characterized in that, The chiral agent is one or more of the compounds represented by the following formulas (III-1) - (III-7); （Ⅲ-1）； （Ⅲ-2）； （Ⅲ-3）； （Ⅲ-4）； （Ⅲ-5）； （Ⅲ-6）； （Ⅲ-7）。 9. A PDLC dimming film, characterized in that, Prepared from the dye PDLC material composition according to any one of claims 1 - 8.

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