WO2018194403A1 - Light transmittance control film and light transmittance control film composition - Google Patents

Abstract

Provided are a light transmittance control film composition and a light transmittance control film. According to the present invention, the light transmittance control film comprises: matrix parts comprising a copolymer and a polymer chain grafted on the copolymer; and dispersed parts comprising a polymer induced from a first monomer and provided in the matrix parts, the polymer chain being induced from the first monomer, wherein a first light transmittance can be exhibited while an external force is applied and a second light transmittance higher than the first light transmittance can be exhibited when the external force is removed.

Description

Light transmittance control film and light transmittance control film composition

The present invention relates to a light transmittance adjusting film composition and a light transmittance adjusting film.

The present invention discloses a liquid crystal or electrochromic molecule that improves the disadvantages of a film type light transmission control module based on liquid crystals or polarized particles, and a light transmission control film based on no dispersion particles.

The light amount control method using low-molecular liquid crystals (Liquid Crystals, LCs) has a disadvantage in that the power consumption according to the light consumption increases because of the use of polarization in principle, and uses such components as polarizing plates and expensive liquid crystal materials. The amount of light control using polymer-dispersed liquid crystals (PDLCs) has caused a problem of low light blocking rate due to scattering of light even when an electric field is not applied. Light absorption control method through oxidation and reduction of electrochromic material and orientation of dichroic dyes and particles dispersed and suspended in polymer, respectively, has high manufacturing cost according to materials and packaging, and changes in transmittance due to limitation of light control mechanism. The disadvantage is as low as 30-50%.

The present invention is to provide a film for easily adjusting the light transmittance without an electric field and a light transmittance adjusting film composition for producing the same.

The present invention is not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

The present invention relates to a light transmittance adjusting film and a light transmittance adjusting film composition. According to the present invention, the light transmittance controlling film comprises a matrix portion comprising a copolymer and a polymer chain bonded to the copolymer; And a polymer derived from a first monomer, comprising a dispersed portion provided in the matrix portions, wherein the polymer chain can be derived from the first monomer. The light transmittance adjusting film exhibits a first light transmittance while the external force is applied; When the external force is removed, the second light transmittance may be greater than the first light transmittance.

In example embodiments, the second light transmittance may be about 35% to about 95% transmittance of light in a visible region.

According to embodiments, while the external force is applied, several voids are provided between the dispersed portion and the matrix portion, and when the external force is removed, the voids may disappear.

According to embodiments, the dispersed portion may have a larger initial elastic modulus than the matrix portion.

According to embodiments, the dispersed portion may have an initial elastic modulus of about 100 times to about 100,000 times that of the matrix portion.

According to embodiments, the difference in refractive index between the matrix portion and the dispersed portion may be less than 5%.

According to embodiments, the external force may include a tensile force.

According to embodiments, the first monomer may be represented by the following formula (1).

[Formula 1]

In Formula 1, A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and R1 is hydrogen, halogen, a linear or branched alkyl group having 1 to 8 carbon atoms, or 1 carbon atom. A halogen substituted linear or branched alkyl group of 8 to 8, and R2, R3, and R4 are each independently hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms.

In example embodiments, the matrix portion may be represented by Formula 6A below.

[Formula 6A]

In formula (6A), R11 is represented by the following formula (2B), and R12, R13, and R14 are each independently hydrogen, halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms. R15 may include at least one of the materials represented by the following Chemical Formula 6B, and R16 may include at least one of the materials represented by the following Chemical Formula 6B.

[Formula 2B]

In Formula 2B, * means a moiety bonded to Si of Formula 6A, and B is a single bond or a linear or branched alkyl group having 1 to 5 carbon atoms, carbonyl group, ester group, acetate group, amide group, or -S- CO-, and R21, R22, and R23 are each independently hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms.

 [Formula 6B]

In formula (6B), * means a moiety bonded to Si in formula (6A), A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and B is a single bond, carbon number Linear or branched alkyl group of 1 to 5, carbonyl group, ester group, acetate group, amide group or -S-CO-, R1 is hydrogen, halogen, linear or branched alkyl group of 1 to 8 carbon atoms, or 1 carbon atom A halogen substituted linear or branched alkyl group of 8 to 8, R 2, R 3, and R 4 are each independently hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms, and R 21, R 22, and R 23 are each independently Hydrogen, halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms, and m6 is an integer selected from 1 to 100.

[Formula 6C]

In formula (6C), * means a moiety bonded to Si of formula (6A), A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and B is a single bond, carbon number Linear or branched alkyl group of 1 to 5, carbonyl group, ester group, acetate group, amide group or -S-CO-, R1 is hydrogen, halogen, linear or branched alkyl group of 1 to 8 carbon atoms, or 1 to C A halogen substituted linear or branched alkyl group of 8, R 2, R 3, and R 4 are each independently hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms, and R 21, R 22, and R 23 are each independently hydrogen , A halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms, and m7 is an integer selected from 1 to 100.

According to the present invention, the light transmittance adjusting film composition comprises a first monomer; And a copolymer comprising a first polymer derived from the second monomer and a second polymer derived from a third monomer, wherein the molar ratio of the first polymer and the first monomer in the copolymer is from 1: 5 to 1 The molar ratio of the first polymer and the second polymer in the copolymer may be 1: 4 to 1: 200.

According to embodiments, the first monomer may be represented by the following formula (1).

[Formula 1]

In Formula 1, A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and R1 is hydrogen, halogen, a linear or branched alkyl group having 1 to 8 carbon atoms, or 1 carbon atom. A halogen substituted linear or branched alkyl group of 8 to 8, and R2, R3, and R4 are each independently hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms.

According to embodiments, the first polymer may include a polymerization unit represented by Formula 2A.

[Formula 2A]

In formula (2A), R11 is represented by formula (2B) below, R12 is hydrogen, halogen, linear or branched alkyl group of 1 to 5 carbon atoms, or substituted or unsubstituted phenyl group of 6 to 13 carbon atoms, m1 is 2 to 50 Is an integer between.

[Formula 2B]

In formula (2B), B is a single bond or a linear or branched alkyl group having 1 to 5 carbon atoms, carbonyl group, ester group, acetate group, amide group, or -S-CO-, and R21, R22, and R23 are each independently Hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms.

According to embodiments, the second polymer may include a polymerization unit represented by Formula 3.

 [Formula 3]

In formula (3), R13 and R14 are each independently hydrogen, halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms, and m2 is an integer between 10 and 10,000.

According to embodiments, the first monomer comprises t -butyl acrylate, the copolymer comprises a silicone copolymer represented by the formula (4B) below, the silicone copolymer has a weight average molecular weight of 5,000 to 500,000 The silicone copolymer may be dissolved in the t -butyl acrylate monomer.

[Formula 4B]

In Formula 4B, the ratio of m1 to m2 is 1: 4 to 1: 200.

According to embodiments, the molar ratio of the t -butyl acrylate monomer to the total molar ratio of the vinyl group included in the copolymer may be 1: 5 to 1: 100.

According to embodiments, the polymerization initiator may further include.

In some embodiments, at least one of the first monomer and the copolymer may include a vinyl group, and the polymerization initiator may be 0.05 to 5 mol% based on the total of the vinyl groups.

According to the present invention, according to the application of the external force and the intensity of the applied external force, the light transmittance of the film of the present invention can be adjusted. The transmittance of the light transmittance adjusting film may be reduced by the stress whitening phenomenon. The light transmittance adjusting film may have good elastic recovery properties. Once the external force is removed, the light transmittance adjusting film may return to its initial state before the external force is applied. Accordingly, light transmittance can be easily adjusted. The light transmittance adjusting film can be simply produced by the photopolymerization reaction of the light transmittance adjusting film composition.

For a more complete understanding and help of the invention, reference is given to the following description together with the accompanying drawings and reference numbers are shown below.

1 is a schematic diagram showing a light transmittance control film composition according to embodiments of the present invention.

2 is a schematic plan view of a light transmittance adjusting film according to the embodiments.

FIG. 3 schematically shows a molecular chain composition of the light transmittance adjusting film of FIG. 2.

4 is a perspective view illustrating a manufacturing process of a light transmittance adjusting film according to embodiments.

5 is a view for explaining a light transmittance adjusting method using the light transmittance adjusting film of FIG.

6 is according to the wavelength of the Experimental Example F 1-20, Experimental Example F 1-30, Experimental Example F 2-20, Experimental Example F 2-30, Experimental Example F 3-20, and Experimental Example F 3-30 film It is a graph showing the light transmittance.

Figure 7a is a result showing the light transmittance according to the tensile strain (tensile strain) of the film of Experimental Example F 3-20.

7B is a result of analyzing light transmittances of Experimental Examples F 2-20, Experimental Examples F 3-20, and Experimental Examples F 3-30 according to the wavelengths when a tensile strain of 0.2 was applied to the light transmittance adjusting film.

8A is a scanning electron microscope (Scanning Electron Microscope, SEM) planar image of the Experimental Example F 2-20 film with a tensile strain of 0.2 applied to the light transmittance controlling film.

8B is a planar image of Experimental Example F 2-20 film, with a tensile strain of 0.4 applied to the light transmittance controlling film.

8C is an SEM plane image of Experimental Example F 2-20 film, with a tensile strain of 0.8 applied to the light transmittance controlling film.

9 is a differential scanning of films of Experimental Example F 1-20, Experimental Example F 1-30, Experimental Example F 2-20, Experimental Example F 2-30, Experimental Example F 3-20, and Experimental Example F 3-30. The calorimetry result (DSC) is shown.

10A, 10B, 10C, and 10D are transmission electron microscopes of Experimental Examples F 1-20, Experimental Examples F 2-20, Experimental Examples F 3-20, and Experimental Examples F 3-30 films, respectively. Cross-sectional images of a microscope (TEM).

FIG. 11A shows a photo image of Experimental Example F 3-20 film with no tensile force applied. FIG.

11B shows a photo image of Experimental Example F 3-20 film while tensile force is applied.

11C shows a photo image of Experimental Example F 3-20 film with tensile force applied thereto.

In order to fully understand the constitution and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various forms and various changes may be made. Only, the description of the embodiments are provided to make the disclosure of the present invention complete, and to provide a complete scope of the invention to those skilled in the art. Those skilled in the art will understand that the concept of the present invention may be carried out in any suitable environment.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, the words "comprises" and / or "comprising" refer to the presence of one or more other components, steps, operations and / or elements. Or does not exclude additions.

Where it is mentioned herein that a film (or layer) is on another film (or layer) or substrate, it may be formed directly on another film (or layer) or substrate or a third film (between) Or layers) may be interposed.

 Although terms such as first, second, third, etc. are used to describe various regions, films (or layers), etc. in various embodiments of the present specification, these regions, films should not be limited by these terms. do. These terms are only used to distinguish any given region or film (or layer) from other regions or films (or layers). Therefore, the film quality referred to as the first film quality in one embodiment may be referred to as the second film quality in other embodiments. Each embodiment described and illustrated herein also includes its complementary embodiment. Portions denoted by like reference numerals denote like elements throughout the specification.

Unless otherwise defined, terms used in the embodiments of the present invention may be interpreted as meanings commonly known to those skilled in the art.

The film composition according to the present invention will be described.

1 is a schematic diagram showing a light transmittance control film composition according to embodiments of the present invention.

Referring to FIG. 1, the light transmittance adjusting film composition 10 may include a first monomer 100 and a copolymer 200. The first monomers 100 may be represented by Formula 1 below.

[Formula 1]

In Formula 1, A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and R1 is hydrogen, halogen, a linear or branched alkyl group having 1 to 8 carbon atoms, or 1 carbon atom. And a halogen substituted linear or branched alkyl group of 8 to 8, and R2, R3, and R4 may each independently be hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms.

According to an embodiment, the first monomer 100 may include an acrylic monomer or a vinyl monomer. The first monomer 100 is, for example, styrene, 2,3,4,5,6-pentafluoro styrene (2,3,4,5,6-pentafluoro styrene), methyl acrylate, methyl methacrylate , Ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, t-butyl acrylate, t-butyl methacrylate, hexyl acrylate, hexyl methacrylate, octyl acrylate, octyl methacrylate, Octadecyl acrylate, octadecyl methacrylate, dodecyl acrylate, dodecyl methacrylate, vinyl acetate, trifluoroacetic acid allyl ester, trifluoroacetic acid vinyl ester 2,2,2-trifluoroethyl methacrylate, acrylic acid 1,1,1,3,3,3-hexafluoroisopropyl ester (acrylic acid 1,1 , 1,3,3,3-hexafluorois opropyl ester), methacrylic acid 1,1,1,3,3,3-hexafluoroisopropyl ester (methacrylic acid 1,1,1,3,3,3-hexafluoroisopropyl ester), and 1-pentafluoro It may include at least one selected from phenylpyrrole-2,5-dione (1-pentafluorophenylpyRole-2,5-dione).

The copolymer 200 may include a first polymer and a second polymer. The weight average molecular weight of the copolymer 200 may be 5,000 to 500,000. The first polymer may comprise a polymerization unit derived from the second monomer. The first polymer may include a polymerization unit represented by Formula 2A below.

[Formula 2A]

In Formula 2A, R11 may be represented by the following Formula 2B. R12 may be hydrogen, halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms. m1 may be an integer between 2 and 50.

 [Formula 2B]

In formula (2B), B is a single bond or a linear or branched alkyl group having 1 to 5 carbon atoms, carbonyl group, ester group, acetate group, amide group, or -S-CO-, and R21, R22, and R23 are each independently Hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms.

The first polymer may comprise a reactor. The reactor may be a group represented by Formula 2B.

The second polymer may be combined with the first polymer. The second polymer may include a polymerization unit represented by the formula (3). The second polymer can be derived from the third monomer. The third monomer may be different from the first monomer 100 and the second monomer.

[Formula 3]

In Formula 3, R13 and R14 may each independently be hydrogen, halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms. m2 is an integer between 10 and 10,000.

In the light transmittance control film composition 10, the ratio of the total number of the polymerization units of the first polymer in the copolymer 200 to the number of moles of the first monomer 100 may be 1: 5 to 1: 100. Here, the sum of the polymerization units of the first polymer may be, for example, the sum of m1 in Formula 2A.

According to an embodiment, the copolymer 200 may be represented by the following Chemical Formula 4A.

[Formula 4A]

In formula 4A, R12, R13, and R14 are each independently hydrogen, halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms, and m1 is selected from 2 to 50 Integer, m2 is an integer between 10 and 10,000, m1: m2 may be 1: 4 to 1: 200. R11 may be represented by Chemical Formula 2B.

The copolymer 200 may be prepared by a polymerization reaction of a second monomer and a third monomer as in Scheme 1 below.

Scheme 1

In Scheme 1, R11, R12, R13, R14, m1, and m2 are as defined in Formula 2A, Formula 2B, and Formula 4A.

The light transmittance adjusting film composition 10 may further include a polymerization initiator 300. The polymerization initiator 300 may include a photopolymerization initiator. The polymerization initiator 300 may include, for example, 2,2-dimethoxy-2-phenylacetophenone. As another example, the polymerization initiator 300 may include a thermal polymerization initiator.

According to an embodiment, the first monomer 100 includes t -butyl acrylate, the copolymer 200 includes a silicone copolymer represented by the following Chemical Formula 4B, and the silicone copolymer has a weight of 5,000 to 500,000. It may have an average molecular weight. The silicone copolymer can be dissolved in t -butyl acrylate.

[Formula 4B]

In Formula 4B, the ratio of m1 to m2 is 1: 4 to 1: 200.

The molar ratio of t -butyl acrylate relative to the total molar ratio of vinyl groups included in the copolymer 200 may be 1: 5 to 1: 100. At least one of the first monomer 100 and the copolymer 200 may include a vinyl group. When the light transmittance control film composition 10 further includes a polymerization initiator 300, the polymerization initiator 300 may be 0.05 mol% to 5 mol% with respect to the total of the vinyl groups.

In general, semicrystalline polymers, such as polyethylene, polypropylene, polyoxymethylene, polyethylene terephthalate, and polyamide, have several nano size in the process of developing amorphous regions from lamellar crystals upon stretching. A void is created, which grows to tens or hundreds of nanoscales that can cause light scattering when pulled to near fracture, resulting in stress-whitening due to tensile stress at break. It is known to not appear in compressive or torsional stresses. Alternatively, when tensioning a composite film in which a heteropolymer or an inorganic material is dispersed in a polymer matrix regardless of the crystallinity of the polymer, the spaces at the interface between the polymer and the dispersion may be caused by the difference in tensile strain between the polymer matrix and the dispersion. These spaces can grow and grow to a size that will cause light scattering with continuous tension, causing whitening that makes the film opaque by scattering visible light passing through the film near the fracture of the film. However, since this phenomenon occurs near the fracture of the polymer film, light transmittance control due to stress whitening is irreversible to the change in film tensile stress. In addition, since the stress whitening mainly occurs in the polymer composite film in which the semi-crystalline polymer or the dispersion is dispersed, the light transmittance of the initial polymer film may be reduced by light scattering of the crystal region or the dispersion before the application of the tensile stress.

The light transmittance control film in the present invention is a film in which the light transmittance of the film is adjusted according to the mechanical strain or stress applied by using the stress whitening phenomenon of the polymer.

Hereinafter, a light transmittance adjustment film and its manufacturing method are demonstrated.

2 is a schematic plan view of a light transmittance adjusting film according to the embodiments. FIG. 3 schematically shows a molecular chain composition of the light transmittance adjusting film of FIG. 2. Hereinafter, descriptions overlapping with those described above will be omitted.

Referring to FIG. 2, the light transmittance adjusting film 1000 may include a dispersed portion P1 and a matrix portion P2. Light transmittance control using the light transmittance adjusting film 1000 will be described in more detail with reference to FIG. 5. The dispersed portion P1 may be provided in the matrix portion P2. The dispersed portion P1 may have the shape of circles or ellipses. The dispersed portion P1 may have maximum diameters of 10 nm to 500 nm.

The matrix portion P2 may serve as a matrix of the light transmittance adjusting film 1000. The content ratio and volume of the matrix portion P2 may be smaller than the content ratio and volume of the dispersed portion P1. The matrix portion P2 may comprise a polymerization unit derived from the dispersed portion P1 and other monomers. The matrix portion P2 may have compatibility with the dispersed portion P1.

The light transmittance adjusting film 1000 may have an initial elastic modulus of 50 MPa or less. The dispersed portion P1 of the light transmittance adjusting film 1000 may have a larger initial elastic modulus than the matrix portion P2. The dispersed portion P1 may be at least 100 times the initial modulus of elasticity of the matrix portion P2, in particular 100 to 100000 times. The initial elastic modulus of the matrix portion P2 may be 0.01 MPa to 1 MPa, and the initial elastic modulus of the dispersed portion P1 may be 100 MPa or more, specifically 100 MPa to 100,000 MPa. In the present specification, the initial elastic modulus may mean an initial elastic modulus at room temperature, for example, 25 ° C. Matrix portion P2 may have a greater strain for forces of the same intensity than scattered portion P1. Matrix portion P2 may have good elastic recovery characteristics.

Matrix portion P2 may have the same or similar refractive index as dispersed portion P1. For example, the difference between the refractive indices of the matrix portion P2 and the dispersed portions P1 may be less than 5%. When the refractive index of the matrix portion P2 is excessively larger than the refractive index of the dispersed portion P1 (eg, a refractive index difference of 5% or more), the light transmittance of the light transmittance adjusting film 1000 may decrease. Hereinafter, the manufacturing method of the dispersed part P1 and the matrix part P2 is demonstrated.

2 and 3, the dispersed portion P1 may include homo polymers. The dispersed portion P1 may comprise a polymerization unit derived from the first monomer 100. The first monomer 100 may be represented by Chemical Formula 1. Accordingly, the dispersed portion P1 may include a polymer represented by Formula 5 below.

[Formula 5]

In formula (5), A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and R1 is hydrogen, halogen, a linear or branched alkyl group having 1 to 8 carbon atoms, or 1 carbon atom. And a halogen substituted linear or branched alkyl group of 8 to 8, and R2, R3, and R4 may each independently be hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms. n is an integer between 2 and 5000.

As another example, the dispersed portion P1 may include inorganic materials.

Matrix portion P2 may include copolymer 200 and polymer chains 110. The copolymer 200 may be random, alternating, or in block form. The copolymer 200 may serve as a main chain. The copolymer 200 may include a first polymer and a second polymer as described above with reference to FIG. 1. The second polymer may be represented by Formula 3 above. After the curing of the light transmittance control film composition 10 of FIG. 1, the polymer chains 110 may be formed and grafted to the copolymer 200. The polymer chains 110 may be bonded to the first polymer after the light transmittance control film composition 10 is cured. The polymer chains 110 may include polymerization units derived from the first monomer 100. After the light transmittance control film composition 10 is cured, the matrix portion P2 may be represented by the following Chemical Formula 6A. In this case, the matrix portion P2 may have a weight average molecular weight of approximately 5,000 to 500,000.

[Formula 6A]

In Formula 6A, R11 is represented by Formula 2B, and R12, R13, and R14 are each independently hydrogen, halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms. Can be. The sum of m3, m4, and m5 may be the same as m1 of formula 4A. R15 may be represented by the following Chemical Formula 6B. R16 may be represented by the following Chemical Formula 6C.

 [Formula 6B]

In formula (6B), * means a moiety bonded to Si in formula (6A), A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and B is a single bond, carbon number Linear or branched alkyl groups, carbonyl groups, ester groups, acetate groups, amide groups, or -S-CO-. R 1 is hydrogen, halogen, a linear or branched alkyl group having 1 to 8 carbon atoms, or a halogen substituted linear or branched alkyl group having 1 to 8 carbon atoms, and R 2, R 3, and R 4 are each independently hydrogen, halogen, or 1 carbon atom; It may be a linear or branched alkyl group of 5 to 5. R21, R22, and R23 may each independently be hydrogen, halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms. m6 is an integer selected from 1 to 100.

[Formula 6C]

In formula (6C), * means a moiety bonded to Si of formula (6A), A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and B is a single bond, carbon number Linear or branched alkyl group of 1 to 5, carbonyl group, ester group, acetate group, amide group or -S-CO-, R1 is hydrogen, halogen, linear or branched alkyl group of 1 to 8 carbon atoms, or 1 to C A halogen substituted linear or branched alkyl group of 8, R 2, R 3, and R 4 are each independently hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms, and R 21, R 22, and R 23 are each independently hydrogen , A halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms, and m7 is an integer selected from 1 to 100.

1 and 3, the light transmittance adjusting film 1000 may be manufactured using the light transmittance adjusting film composition 10 described with reference to FIG. 1. For example, the dispersed portion P1 and the matrix portion P2 may be formed by a polymerization reaction of the light transmittance adjusting film composition 10. The polymerization reaction of the light transmittance adjusting film composition 10 may be initiated by light or heat. Manufacturing of the light transmittance control film 1000 is to form a portion (P1) dispersed by the polymerization reaction of the first monomer (100) and graft polymerization of the first monomer (100) to the copolymer 200 Or crosslinking. The polymerization reaction of the first monomer 100 and the copolymer 200 may be performed by a graft polymerization reaction. At this time, the vinyl group of the first polymer may act as a reactor to bond with the polymer chains 110.

The light transmittance control film composition 10 may include a plurality of copolymers 200. During the polymerization reaction, the copolymers 200 may be directly crosslinked with each other or connected to each other through at least one of the polymer chains 110. Accordingly, the matrix portion P2 shown in FIG. 3 can be manufactured. As another example, the matrix portion P2 may further comprise fourth polymerization units derived from the fourth monomer. In this case, the fourth monomer may be different from the first to third monomers.

The polymer chains 110 of the matrix portion P2 may be derived from the same monomer as the dispersed portion P1, for example the first monomer 100. Accordingly, the matrix portion P2 may be compatible with the dispersed portion P1. For example, although the copolymers 200 have low compatibility with respect to the dispersed portion P1, the amount of t of the grafted polymer 110 in the matrix portion P2 is controlled to adjust the amount of t in the matrix portion ( P2) may have good compatibility with the dispersed part P1.

The molar ratio between the reactor of the copolymer 200 of the light transmittance control film composition 10 and the first monomer 100 is adjusted, such that the grafted polymer 110 and the dispersed portion of the light transmittance control film 1000 The content of P1) can be controlled. The reactor of the copolymer 200 may be a reactor included in the first polymer of the copolymer 200. Accordingly, the content of the dispersed portion P1 and the size of the dispersed particles in the light transmittance adjusting film 1000 may be adjusted. In the present specification, the size may mean the maximum size unless otherwise described.

According to embodiments, the content of the grafted polymer 110 in the matrix portion P2 may be adjusted to control the light transmittance of the light transmittance adjusting film 1000 before external force is applied. For example, even if the refractive index difference of the copolymer 200 of FIG. 3 and the refractive index difference of the dispersed portion P1 exceeds 5%, as the polymer chains 110 are bonded to the copolymer 200, the matrix portion ( As the compatibility between the P2) and the dispersed portion P1 is increased, the scattering particles are smaller, so that light scattering is reduced, so that the light transmittance of the light transmittance adjusting film 1000 may be increased. As the refractive index of the matrix portion P2 is similar to the refractive index of the dispersed portion P1, the light transmittance adjusting film 1000 may have an increased light transmittance.

4 is a perspective view illustrating a manufacturing process of a light transmittance adjusting film according to embodiments. Hereinafter, descriptions overlapping with those described above will be omitted.

Referring to FIG. 4, a first substrate 510, a second substrate 520, a first spacer 530, and a second spacer 540 may be prepared. The second substrate 520 may be vertically spaced apart from the first substrate 510. The first substrate 510 and the second substrate 520 may be glass substrates. The first spacer 530 and the second spacer 540 may be disposed between the first substrate 510 and the second substrate 520. The second spacer 540 may be spaced apart from the first spacer 530 in a horizontal direction. The first spacer 530 and the second spacer 540 may include organic materials such as polyimide. The cavity 550 may be provided between the first substrate 510 and the second substrate 520 and between the first spacer 530 and the second spacer 540.

A light transmittance adjusting film composition (10 in FIG. 1) may be provided on the first substrate 510. The light transmittance adjusting film composition 10 may fill the cavity 550. For example, the light transmittance adjusting film composition 10 may include a first monomer 100, a copolymer 200, and an initiator 300.

 Ultraviolet (UV) light may be applied on the second substrate 520. By performing the UV irradiation, the first monomer 100 homopolymerization and the graft polymerization or crosslinking reaction between the first monomer 100 and the copolymer 200 may be performed in the light transmittance adjusting film composition 10. The polymerization reaction of the light transmittance control film composition 10 may be the same as described above. The light transmittance adjusting film composition 10 may be UV cured. Accordingly, the light transmittance adjusting film 1000 described with reference to FIGS. 2 and 3 may be manufactured.

The light transmittance adjustment method using a light transmittance adjustment film is demonstrated.

5 is a view for explaining a light transmittance adjusting method using the light transmittance adjusting film of FIG. Hereinafter, descriptions overlapping with those described above will be omitted.

Referring to FIG. 2, the light transmittance adjusting film 1000 may be in a state where no external force (eg, tensile force) is applied. In this case, the light transmittance adjusting film 1000 may be transparent. For example, the light transmittance adjusting film 1000 may have a transmittance of 35% to 95% for visible light. Visible light may mean light having a wavelength of 400nm to 700nm. The matrix portion P2 may be compatible with the dispersed portion P1. A void may not be provided between the dispersed portion P1 and the matrix portion P2. As another example, if there is a void between the dispersed portion P1 and the matrix portion P2, the void may be very small. Matrix portion P2 may have the same or similar refractive index as dispersed portion P1. When the refractive index of the matrix portion P2 is excessively different from the refractive index of the dispersed portion P1 or when the compatibility between the dispersed portion P1 and the matrix portion P2 is very low, the light transmittance adjusting film 1000 Light transmittance may be reduced. According to embodiments, the difference between the refractive index of the matrix portion P2 and the refractive index of the dispersed portion P1 may be less than 5%. When the dispersed portion P1 and the matrix portion P2 show crystallinity, the light transmittance of the light transmittance adjusting film 1000 may decrease. According to embodiments, the dispersed portion P1 and the matrix portion P2 may be amorphous.

Referring to FIG. 5, an external force may be applied to the light transmittance adjusting film 1000. The external force may be a tensile force. The external force may be above a certain intensity. When an external force is applied, the light transmittance adjusting film 1000 may have a reduced transmittance due to stress-whitening. The matrix portion P2 has a relatively small initial elastic modulus and can be stretched by the external force. In FIG. 5, the dotted line represents the matrix portion P2 before the tensile force is applied. The initial modulus of elasticity of the matrix portion P2 may be, for example, 0.01 MPa to 1 MPa. The dispersed portion P1 has a relatively large initial elastic modulus so that when external force is applied, it is less likely to be increased by the external force than the matrix portion P2. For example, the initial modulus of elasticity of the dispersed portion P1 may be 100 MPa or more, specifically 100 MPa to 100,000 MPa. As another example, the elongation of the dispersed portion P1 may be very small compared to the elongation strain of the matrix portion P2. Accordingly, voids 400 may be formed between the dispersed portion P1 and the matrix portion P2. As another example, when a tensile force is applied, the voids 400 may have a larger volume than the voids (not shown) in the state where no tensile force is applied. The pores 400 may be vacuum or air may be provided in the pores 400. The dispersed portion P1 and the matrix portion P2 may have a large refractive index difference from the void 400. Light passing through the stretched film may be scattered or reflected by the difference in refractive index. Accordingly, the light transmittance of the light transmittance adjusting film 1000 may be reduced. For example, the light transmittance adjusting film 1000 may be opaque.

As described above, the dispersed portion P1 may have particles of maximum diameters of 10 nm to 500 nm. If the maximum diameter of the particles of the dispersed portion P1 is smaller than 10 nm, the volume of the voids 400 generated between the dispersed portion P1 and the matrix portion P2 may be reduced. Accordingly, even when a tensile force is applied to the light transmittance adjusting film 1000, the light transmittance change of the light transmittance adjusting film 1000 may not be large. For example, the light transmittance adjusting film 1000 may be transparent. In this case, the light transmittance adjusting film 1000 may be difficult to adjust the light transmittance. When the maximum diameter of the particles in the dispersed portion P1 is larger than 500 nm, the light transmittance adjusting film 1000 may be opaque by the dispersed particles themselves. Accordingly, even when a tensile force is applied to the light transmittance adjusting film 1000, the light transmittance change of the light transmittance adjusting film 1000 may not be large. In this case, the light transmittance adjusting film 1000 may be difficult to adjust the light transmittance.

Referring back to FIG. 2, the external force applied to the light transmittance adjusting film 1000 may be removed. The matrix portion P2 has good elastic recovery properties and can return to its initial state before external force is applied. For example, the initial length of the matrix portion P2 can be recovered without deformation as described in FIG. 5. The voids 400 may disappear between the dispersed portion P1 and the dispersed portion P1 and the matrix portion P2. Accordingly, the light transmittance adjusting film 1000 may be transparent again. For example, the light transmittance adjusting film 1000 may have a transmittance of 35% to 95% for the visible light region. According to embodiments, the intensity of light passing through the light transmittance adjusting film 1000 may be adjusted according to whether an external force is applied to the light transmittance adjusting film 1000. That is, the stress whitening phenomenon of the light transmittance adjusting film 1000 may be reversibly controlled, and thus the light transmittance may be reversibly controlled. By the photopolymerization reaction of the light transmittance adjusting film composition 10, the light transmittance adjusting film 1000 may be simply manufactured. When the light transmittance adjusting film 1000 is used in the LCD (display) module, a separate polarizing plate may be omitted in the display module. In this case, the display module can be miniaturized. When the light transmittance adjusting film 1000 is used in a window, the light transmittance adjusting film 1000 may be applied to a smart window that controls an external or internal view.

Hereinafter, with reference to the experimental examples of the present invention, the production of the composition and the film will be described.

Preparation of the composition

1-1. Preparation of Copolymer (Experimental Example PDMS 1)

70.08 g (473 mmol) of diethoxydimethylsilane and 2.35 g (14.7 mmol) of diethoxymethylvinylsilane (feed molar ratio = 97.0: 3.0) were added to a 250 ml three-necked flask at room temperature (about 25 ° C) under nitrogen. ml (37%) was added slowly. The reaction temperature was then raised to about 70 ° C. After carrying out the polymerization reaction for about 24 hours under a nitrogen stream of 70 ml / min, the temperature is lowered to room temperature. After dissolving the high viscosity copolymer in 200 ml of ethyl acetate (EA), the polymer EA solution was poured into 700 ml of water to remove the catalyst. After separating the polymer EA solution layer from the water layer for 1 day, the remaining water was removed from the polymer EA solution using magnesium sulfate. Magnesium sulfate was filtered off and EA was removed with a vacuum evaporator at room temperature, and then the transparent colorless high viscosity polymer was vacuum dried at 35 ° C. for 2 days to obtain Experimental Example PDMS 1.

Experimental Example Preparation of PDMS 1 (Poly (dimethylsiloxane-co-methylvinylsiloxane))

Experimental Example For identification of PDMS 1, gel permeation chromatography (GPC), Fourier Transform Infrared spectroscopy (IR), and Proton nuclear magnetic resonance spectroscopy (hereinafter, referred to as ¹⁾ H-NMR) was performed and the yield calculated.

Gel permeation chromatography was performed using a Waters 2690 Alliance gel permeation chromatograph equipped with a refractive index detector, flowing tetrahydrofuran (THF) solvent at 0.6 mL / min. Infrared spectroscopy was performed using a Nicolet 6700 FT-IR spectrometer. Hydrogen magnetic resonance spectroscopy was performed using a Bruker 500 MHz NMR spectrometer and chloroform-d ₁ (CDCl ₃ ) was used as a solvent.

Yield: 33.0 g (91%);

GPC (THF, polystyrene standard): M _n = 105,832; PD = 1.61.

IR v _max (Liquid, NaCl) / cm ^-1 : 3055w (= CH str., Vinyl); 2963s (CH str., Methyl); 1598 w (C = C str., Vinyl); 1411 m (CH benzene, methyl); 1097 s (Si-O str., Siloxane). ¹ H NMR δ _H (CDCl ₃ , 500 MHz): 5.92-6.04 (2H, m, vinyl); 5.77-5.82 (H, m, vinyl); 0.07-0.10 (9H, m, methyl)

Experimental Example GPC analysis was performed to measure the molecular weight and molecular weight distribution of PDMS 1. The number average molecular weight of PDMS 1 was about 10.6 x 10 ⁴ g / mol, and the weight average molecular weight was 17.1 x 10 ⁴ g / mol. The molecular weight dispersion of PDMS 1 was calculated to be 1.61.

Experimental Example ¹ H-NMR analysis of PDMS 1 showed peaks at 0.1 ppm, 5.8 ppm, and 6.0 ppm, respectively. The peak near 0.1 ppm is hydrogen of Si-CH ₃ , and the vicinity of 5.8 ppm is CH of -CH = CH ₂ . In hydrogen, 5.9-6.0 ppm corresponds to CH ₂ hydrogen of —CH═CH ₂ . When quantifying the hydrogen of each environment in consideration of the integral values of the relative peaks, the ratio of the polymerization unit containing dimethylsiloxane (m2 in Formula 2A) and the polymerization unit (m1 in Formula 2A) containing methylvinylsiloxane in Experimental Example PDMS 1 It was calculated as about 0.97 and 0.03, respectively. From this, it was analyzed that the molar ratio of the polymerization units of the copolymer of Experimental Example PDMS1 almost matched the feeding mole ratio of monomers. From the above results, it was confirmed that Experimental Example PDMS 1 contains Poly (dimethylsiloxane-co-methylvinylsiloxane).

1-2. Preparation of Copolymer (Experimental Example PDMS 2)

Copolymers were prepared in the same manner as in Experimental Example PDMS1. However, 80.01 g (540 mmol) of diethoxydimethylsilane and 5.55 g (34.6 mmol) of diethoxymethylvinylsilane (feeding mole ratio = 94.0: 6.0) were used as starting materials. 8.9 mL of distilled water and 2.3 mL of hydrochloric acid (37%) were added as a polymerization catalyst.

Experimental Example Preparation of PDMS 2 (Poly (dimethylsiloxane- co -methylvinylsiloxane)

Experimental Example PDMS 2 yield calculation, gel permeation chromatography (GPC) analysis, infrared spectroscopy, and hydrogen nuclear magnetic resonance spectroscopy (^OneH-NMR) was performed in the same manner as PDMS 2.

Yield: 39.9 g (93%)

GPC (THF, polystyrene standard): Mn = 108,379; PD = 1.42

IR vmax (Liquid, NaCl) / cm ^-1 : 3055w (= CH str., Vinyl); 2963s (CH str., Methyl); 1598 w (C = C str., Vinyl); 1410 m (CH benzene, methyl); 1093 s (Si-O str., Siloxane). 1 H NMR δ H (CDCl 3, 500 MHz): 5.92-6.04 (2H, m, vinyl); 5.78-5.83 (H, m, vinyl); 0.08-0.11 (9H, m, methyl).

As a result of GPC analysis of Experimental Example PDMS 2, the number average molecular weight of Experimental Example PDMS 2 was about 10.8 × 10 ⁴ g / mol, the weight average molecular weight was 15.4 × 10 ⁴ g / mol, and the molecular weight dispersion degree was 1.42.

Experimental Example ¹ H-NMR analysis of PDMS 2 showed peaks at 0.1 ppm, 5.8 ppm, and 5.9 ppm to 6.0 ppm, respectively. The peak near 0.1 ppm is hydrogen of Si-CH ₃ , and the vicinity of 5.8 ppm is CH of -CH = CH ₂ . In hydrogen, 5.9ppm to 6.0ppm corresponds to hydrogen of CH ₂ -CH = CH _2.

From the above results, it was confirmed that Experimental Example PDMS 2 contains Poly (dimethylsiloxane-co-methylvinylsiloxane). Considering the integral value of each of the peaks, the ratio of the polymerization unit containing dimethylsiloxane (m2 in Formula 2A) and the polymerization unit containing mvinylsiloxane (m1 in Formula 2A) in Experimental Example PDMS 2 was about 0.94 and 0.06, respectively. Was calculated. From this, it was analyzed that the molar ratio of the polymerization units of the copolymer of Experimental PDMS2 was almost identical to the feeding mole ratio of monomers.

1-3. Preparation of Copolymer (Experimental Example PDMS 3)

The copolymer was prepared in the same manner as in Experimental Example PDMS 1. However, 75.01 g (506 mmol) of diethoxydimethylsilane and 11.07 g (69.1 mmol) of diethoxymethylvinylsilane (feeding mole ratio = 88: 12) were used as starting materials. 8.8 mL of distilled water and 2.3 mL of hydrochloric acid (37%) were added as a polymerization catalyst.

Experimental Example Preparation of PDMS 3 (Poly (dimethylsiloxane- co -methylvinylsiloxane)

Experimental Example PDMS 3 yield, gel permeation chromatography (GPC), infrared spectroscopy (IR), and hydrogen nuclear magnetic resonance spectroscopy ( ¹ H-NMR) were performed.

Yield: 40.2 g (93%); GPC (THF, polystyrene standard): M _n = 88,113; PD = 1.60.

IR v _max (Liquid, NaCl) / cm ^-1 : 3055w (= CH str., Vinyl); 2963s (CH str., Methyl); 1598 w (C = C str., Vinyl); 1409 m (CH benzene, methyl); 1093 s (Si-O str., Siloxane). ¹ H NMR δ _H (CDCl ₃ , 500 MHz): 5.92-6.04 (2H, m, vinyl); 5.78-5.85 (H, m, vinyl); 0.08-0.11 (9H, m, methyl).

As a result of GPC analysis of Experimental Example PDMS 3, the number average molecular weight of Experimental Example PDMS 3 was measured to be about 8.8 x 10 ⁴ g / mol, the weight average molecular weight was 14.1 x 10 ⁴ g / mol, and the molecular weight dispersion of the polymer was 1.60. .

From the above results, it was confirmed that Experimental Example PDMS 3 contains Poly (dimethylsiloxane-co-methylvinylsiloxane). In consideration of the integral value of each of the peaks, the ratio of the polymerization unit containing dimethylsiloxane (m2 in Formula 2A) and the polymerization unit containing mvinylsiloxane (m1 in Formula 2A) in Experimental PDMS 3 was about 0.88 and 0.12, respectively. Was calculated. From this, it was analyzed that the molar ratio of the polymerization units of the copolymer of Experimental PDMS2 was almost identical to the feeding mole ratio of monomers.

2-1. Preparation of Light Transmittance Control Film Composition According to Copolymer

A copolymer prepared as described above and t- butyl acrylate (first monomer) are mixed as shown in Table 1 below to prepare a composition.

A polymerization initiator (photoinitiator) is added to the composition. 2,2-dimethoxy-2-phenylacetophenone was used as a polymerization initiator, and 2,2-dimethoxy-2-phenylacetophenone was added so as to be 0.5 mol% relative to the vinyl group equivalent in the mixed solution.

Experimental Example	Mass of PDMS 1 (g)	Mass of PDMS 2 (g)	Mass of PDMS 3 (g)	Weight percent of the copolymer in the composition (wt%)	mass of t- butyl acrylate (g)
PDMS 1-20	0.5716	-	-	20	2.0796
PDMS 1-30	1.0808	-	-	30	2.5375
PDMS 2-20	-	0.7022	-	20	2.8468
PDMS 2-30	-	0.9949	-	30	2.3370
PDMS 3-20	-	-	0.5208	20	2.0905
PDMS 3-30	-	-	0.9878	30	2.3090

It was observed that Experimental Example PDMS 1, Experimental Example PDMS 2, and Experimental Example PDMS 3 exhibited excellent mixing properties with t- butyl acrylate. It was observed that the polymerization initiator was dissolved in t -butyl acrylate.

2-2. Preparation of the Film Composition According to the First Monomer

The copolymer and the first monomer are mixed as in Table 2 below to prepare a composition. An initiator is added to the composition. 2,2-dimethoxy-2-phenylacetophenone was used as an initiator, and 2,2-dimethoxy-2-phenylacetophenone was added so as to be 0.5 mol% relative to the vinyl group equivalent in the mixed solution.

Sample name	PDMS 2 (g)	PDMS 3 (g)	First monomer	Usage amount of the first monomer (g)
PDMS-A	-	0.3611	Methyl acrylate	1.4222
PDMS-B	-	0.3812	Ethyl acrylate	1.5497
PDMS-C	-	0.3273	Methyl methacrylate	1.3305
PDMS-D	-	0.3071	Vinyl acetate	1.2435
PDMS-E	-	0.3021	Styrene	1.2016
PDMS-F	-	0.3457	Butyl acrylate	1.3610
PDMS-G	0.3228	-	Hexyl acrylate	1.2968
PDMS-H	0.3709	-	Octyl acrylate	1.4883

3. Preparation of Light Transmittance Control Film

The first spacer and the second spacer are horizontally spaced apart from the first substrate and the second substrate. Glass substrates were used as the first and second substrates. 100 μm thick polyimide adhesive tape was used as the first spacer and the second spacer. The cavity is introduced between the first glass substrate and the second glass substrate and between the first spacer and the second spacer. The composition is provided to the cavity using capillary force. Ultraviolet rays are irradiated to the composition for 10 minutes under nitrogen gas flow conditions using an ultraviolet lamp to produce a UV cured film. The UV lamp used a Mercury UVH lamp and the power was 1 kW. The UV intensities of the lamps irradiated to the composition layers are 7.25, 8.85, 0.26 and 0.84 mW at 395-445 (UVV), 320-390 (UVA), 280-320 (UVB) and 250-260 (UVC) nm. Thereafter, the first and second substrates were immersed in distilled water for 24 hours, the UV-cured film was removed from the first and second substrates, and vacuum dried at room temperature for 2 hours. This obtained the light transmittance adjustment film.

Experimental Example F 1-20, Experimental Example F 1-30, Experimental Example F 2-20, Experimental Example F 2-30, Experimental Example F 3-20, and Experimental Example F 3-30 are each Experimental Example PDMS 1-20. , Obtained from films obtained through photocuring using the compositions of Experimental Example PDMS 1-30, Experimental PDMS 2-20, Experimental PDMS 2-30, Experimental PDMS 3-20, and Experimental PDMS 3-30. The result is.

Hereinafter, descriptions will be given with reference to FIGS. 1, 2, and 3 in the descriptions of FIGS. 6 to 12C.

6 is according to the wavelength of the Experimental Example F 1-20, Experimental Example F 1-30, Experimental Example F 2-20, Experimental Example F 2-30, Experimental Example F 3-20, and Experimental Example F 3-30 films It is a graph showing the light transmittance.

Referring to Figure 6, Experimental Example F 1-20, Experimental Example F 1-30, Experimental Example F 2-20, Experimental Example F 2-30, Experimental Example F 3-20, and Experimental Example F 3-30 films It can be confirmed that it has a high light transmittance with respect to the visible light region. As the molar ratio of the first polymer increases, the light transmittance of the light transmittance adjusting film 1000 increases.

Referring to FIG. 6, as the molar ratio of the first polymer in the light transmittance adjusting film composition 10 increases, the first monomer 100 may further react with the first polymer during the polymerization reaction. In the polymerization process, polymerization between the first monomers 100 may be relatively reduced. Therefore, compatibility may be increased with respect to the portion P1 in which the matrix portion P2 is dispersed. The homopolymers polymerized from the first monomer 100 may constitute a dispersed portion P1 in the light transmittance adjusting film 1000. The diameters of the dispersed parts P1 can be reduced with increased compatibility with respect to the dispersed parts P1 where the matrix part P2 is dispersed. When the diameters of the dispersed portion P1 decrease, the light transmittance of the light transmittance adjusting film 1000 may be increased. As the weight percentage of the first monomer 100 in the light transmittance adjusting film composition 10 increases, the polymerization between the first monomers 100 may be relatively increased during the polymerization reaction. Thus, compatibility with respect to the portion P1 in which the matrix portion P2 is dispersed can be reduced. The homopolymers polymerized from the first monomer 100 may constitute the dispersed portion P1 of the light transmittance adjusting film 1000. The diameters of the dispersed parts P1 can be increased with reduced compatibility with respect to the dispersed parts P1 where the matrix part P2 is dispersed. As the diameters of the dispersed portion P1 increase, the light transmittance of the light transmittance adjusting film 1000 may be reduced.

7A shows the light transmittance according to the tensile strain of Experimental Example F 3-20. e500, e600, and e700 are light transmittance regression lines according to the tensile strain of the Experimental Example F3-20 film at wavelengths of 500 nm, 600 nm, and 700 nm, respectively. Table 3 shows the determination coefficients r ² calculated from the regression lines of e500, e600, and e700 in FIG. 7A, respectively.

Referring to FIG. 7A, as the tensile strain increases, the light transmittance of the light transmittance adjusting film 1000 in the visible light region may decrease. Referring to Table 3, the crystal coefficient from the regression line of the light transmittance according to the tensile strain of the light transmittance adjusting film 1000 may be close to one. From this, it can be seen that the light transmittance of the light transmittance adjusting film 1000 decreases linearly with the tensile strain. According to embodiments, the light transmittance of the light transmittance adjusting film 1000 may be controlled by adjusting the intensity of the tensile force applied to the light transmittance adjusting film 1000 in the elastic region of the light transmittance adjusting film 1000. .

	e500	e600	e700
Wavelength of light (nm)	500 nm	600 nm	700 nm
Coefficient of determination	0.9932	0.9921	0.9924

Figure 7b is a result of analyzing the light transmittance of Experimental Example F 2-20, Experimental Example F 3-20, and Experimental Example F 3-30 films according to the wavelength of light in the state that the tensile strain is applied to the light transmittance control film to be. At this time, a tensile strain of 0.2 was applied.

Referring to FIG. 7B together with FIG. 5, under the conditions of the same wavelength and the same tensile strain, light transmittance is higher in the order of Experimental Examples F 3-30, Experimental Examples F 3-20, and Experimental Examples F 2-20 films. As described above in Table 4, the sizes of the portions P1 dispersed in the light transmittance adjusting film 1000 are increased in the order of Experimental Example F 2-20, Experimental Example F3-20, and Experimental Example F 3-30 film. Can be. If the applied tensile force is constant, the larger the sizes of the dispersed portion P1, the larger the volumes of the voids 400 formed between the dispersed portion P1 and the matrix portion P2. The light transmittance change efficiency of the light transmittance adjusting film 1000 may increase as the diameter of the dispersed portion P1 increases. According to an embodiment of the present invention, when a tensile force is applied to the light transmittance adjusting film 1000, the light transmittance change efficiency of the light transmittance adjusting film is determined by the molar ratio of the first polymer or the light transmittance adjusting film composition (10 in FIG. 1). The weight percentage of the first monomer 100 may be adjusted to adjust the weight percentage.

8A is a scanning electron microscope (Scanning Electron Microscope, SEM) image of the Experimental Example F 2-20 film with a tensile strain of 0.2 applied to the light transmittance controlling film. 8B is Experimental Example F 2-20 SEM image with a tensile strain of 0.4 applied to the light transmittance controlling film. 8C is an SEM image of Experimental Example F 2-20 film, with a tensile strain of 0.8 applied to the light transmittance controlling film. Table 4 shows the results of Experimental Example F 2-20 film observed from the SEM image, with tensile strains of 0.2, 0.4, and 0.8 applied to the light transmittance controlling film.

Applied tensile strain	0.2	0.4	0.8
Volume change of the dispersed part P1	X	X	X
Observation result of the voids formed between the dispersed portion P1 and the matrix portion	Voids formed	Formed voids have large volumes	The pores formed have a very large volume.

8A, 8B, 8C, and Table 4, together with FIG. 5, the larger the tensile strain applied, the greater the volume of voids 400 formed between the dispersed portion P1 and the matrix portion P2. Can be increased. At this time, even when a tensile force was applied, there was little change in volume of the dispersed portion P1. This result is because the initial elastic modulus of the dispersed portion P1 is large. The initial modulus of elasticity of poly ( t -butyl acrylate), which is actually the dispersed part (P1), is measured at about 1.14 GPa and is more than 1000 times larger than that of cross-linked PDMS (matrix part (P2)), which is generally measured at less than 1 MPa. The UV cured film made of the composition of Example 2-2 did not show stress whitening due to stretching by tensile force. This is because the initial modulus of elasticity of the homopolymer of the dispersed portion P1 is lower than 100 MPa. If the difference in initial modulus of elasticity of the dispersed portion P1 and the matrix portion P2 is reduced, no void is formed between the dispersed portion P1 and the matrix portion P2 so that the stress whitening does not appear. According to embodiments, the transmittance of the light transmittance adjusting film 1000 may be reduced by using the stress whitening phenomenon of the light transmittance adjusting film 1000. For example, the light transmittance of the light transmittance adjusting film 1000 may be adjusted by adjusting the intensity of the tensile strain applied to the light transmittance adjusting film 1000.

Table 5 shows the initial modulus of elasticity of the films of Experimental Example F 1-20, Experimental Example F 1-30, Experimental Example F 2-20, Experimental Example F 2-30, Experimental Example F 3-20, and Experimental Example F 3-30 , Maximum tensile strength, yield tensile strain, and maximum tensile strain were measured. In Table 5, s.d. in parentheses means the standard deviation. Using TA Instrument RSA-G2, the initial modulus, maximum tensile strength, yield tensile strain, and maximum tensile strain of the test examples were measured.

Experimental Example	Initial Modulus of Elasticity (MPa) (s.d.)	Tensile strength (MPa) (s.d.)	Yield Tensile Strain (s.d.)	Tensile strain (s.d.)
F 1-20	15.67 (1.60)	3.49 (0.16)	0.10 (0.01)	1.02 (0.09)
F 1-30	2.31 (0.32)	3.04 (0.23)	0.22 (0.02)	2.23 (0.24)
F 2-20	16.70 (2.28)	9.03 (0.53)	0.17 (0.006)	1.29 (0.14)
F 2-30	6.47 (1.74)	7.75 (0.82)	0.26 (0.05)	2.60 (0.17)
F 3-20	34.24 (5.18)	12.95 (1.82)	0.17 (0.02)	1.06 (0.20)
F 3-30	9.24 (0.68)	10.29 (0.27)	0.47 (0.07)	2.04 (0.15)

Referring to Table 5, when the weight percentage of the copolymer of the light transmittance control film composition 10 increases, the initial modulus of elasticity decreases, and the yield tensile strain and maximum tensile strain increase. As the molar ratio of the first polymer in the copolymer increases, the maximum tensile strength of the light transmittance controlling film 1000 increases. The maximum tensile strength of the light transmittance adjusting film 1000 may increase as the content of the reactor of the first polymer in the copolymer increases.

The first polymer may have a reactor. As the content of the reactor in the copolymer increases, that is, when the molar ratio of the first polymer in the copolymer increases, the content and size of the dispersed portion P1 in the prepared light transmittance control film 1000 decreases, and the matrix portion The content of the grafted polymer 110 relative to (P2) may be increased. According to the content of the portion P1 dispersed in the light transmittance adjusting film and the content of the grafted polymer 110, the physical properties of the light transmittance adjusting film 1000 may be changed. According to embodiments, by controlling the molar ratio of the first polymer in the light transmittance control film composition 10, the initial elastic modulus, the maximum tensile strength, the yield tensile strain, and the maximum tensile strain of the light transmittance control film 1000 are controlled. Can be.

Figure 9 shows the differential scanning calories of Experimental Example F 1-20, Experimental Example F 1-30, Experimental Example F 2-20, Experimental Example F 2-30, Experimental Example F 3-20, and Experimental Example F 3-30 films. The analysis results are shown. In Figure 9 the horizontal axis represents the temperature, the vertical axis represents the relative heat flow of the reaction. Differential scanning calorimetry was performed using TA Instruments DSC Q20 at a temperature range of -100 ° C. to 150 ° C. at a rate of temperature rise of 10 ° C./min under a nitrogen stream of 50 mL / min.

Referring to Figure 9, Experimental Example F 1-20, Experimental Example F 1-30, Experimental Example F 2-20, Experimental Example F 2-30, Experimental Example F 3-20, and Experimental Example F 3-30 films A peak was observed between 45 ° C. and 50 ° C. at The glass transition temperature of the polymer chains 110 and the dispersed portion P1 (poly ( t -butyl acrylate)) may correspond to this temperature range. Peaks in the region of -55 ° C to -50 ° C were also observed in Experimental Examples F 1-20, Experimental Examples F 1-30, Experimental Examples F 2-20, and Experimental Examples F 2-30 films. The melting temperature of the matrix part P2 corresponds to this temperature range. As the content of the dispersed portion P1 or the content of the first polymer in the light transmittance adjusting film 1000 is increased, it can be seen that heat of fusion in the light transmittance adjusting film 1000 decreases. For the Experimental Examples 3-20 and Experimental Examples 3-30 films, no peak corresponding to the melting temperature of the matrix portion P2 was observed above -100 ° C. Experimental Examples F 1-20, Experimental Examples F 1-30, Experimental Examples F 2-20, Experimental Examples F 2-30, Experimental Examples F 3-20, and Experimental Examples F 3-30 films were obtained at room temperature (25 ° C) It can be seen that the amorphous form.

10A, 10B, 10C, and 10D show Transmission Electron Microscopes of Experimental Examples F 1-20, Experimental Examples F 2-20, Experimental Examples F 3-20, and Experimental Examples F3-30 films. TEM) cross-sectional images. A JEM-ARM200F Cs-Corrected Scanning Transmission Electron microscope was used for the TEM measurements.

10A, 10B, 10C, and 10D, the dispersed portion P1 is densely distributed in the matrix portion P2. Referring to FIG. 10A, an average size of 300 to 500 nm or more was observed in the long axis direction of the dispersed portion P1. The average size in the short axis direction of the dispersed portion P1 is approximately 200 nm or more. Referring to FIG. 10B, an average size of about 200 nm was observed in the long axis direction of the dispersed portion P1. The average size in the minor axis direction of the dispersed portion P1 is approximately 100 nm. Referring to FIG. 10C, the average size in the major axis direction of the dispersed portion P1 is approximately 100 nm to 150 nm. The size in the short axis direction of the dispersed portion P1 is 50 nm to 100 nm. Referring to FIG. 10D, the size was observed to be approximately 100 nm in the long axis direction of the dispersed portion P1. The average size in the short axis direction of the dispersed portion P1 is 50 nm or less.

The vinyl group of the first polymer of the copolymer 200 in the light transmittance controlling film composition 10 may act as a reactor. The first monomers to the reactor in the copolymer 200 used for the preparation of Experimental Examples F 1-20, Experimental Examples F 2-20, Experimental Examples F 3-20, and Experimental Examples F 3-30 films (eg For example, the molar ratio of t -butyl acrylate) is calculated to be 83.0, 42.4, 20.5, and 12.0, respectively. As the content of the first monomer reactor increases, the content ratio of the grafted polymer 110 (eg, the grafted poly ( t -butyl acrylate) group) in the light transmittance controlling film 1000 may increase. Since the grafted polymer chain 110 acts as a compatibilizer between the matrix portion P2 and the dispersed portion P1, the sizes of the dispersed portion P1 can be reduced. The dispersed portion P1 may have elliptical shapes.

FIG. 11A shows a photo image of Experimental Example F 3-20 film with no tensile force applied. FIG. 11B shows a photo image of Experimental Example F 3-20 film while tensile force is applied. 11C shows a photo image of Experimental Example F 3-20 film with tensile force applied thereto.

Referring to FIG. 11A, the light transmittance adjusting film in a state where no tensile force is applied may be transparent.

Referring to FIG. 11B, when a tensile force is applied, the light transmittance of the light transmittance adjusting film 1000 may be reduced. This is because a stress whitening phenomenon occurs as a tensile force is applied to the light transmittance adjusting film 1000. As previously described with reference to FIG. 5 and Table 4, voids 400 occur between the dispersed portion P1 and the matrix portion P2, and the voids 400 are under vacuum or air is present in the voids 400. Can be provided within. The dispersed portion P1 and the matrix portion P2 may have a large refractive index difference with vacuum or air. Visible light may be scattered or reflected by the difference in refractive index. Accordingly, the light transmittance of the light transmittance adjusting film 1000 may be reduced. For example, the light transmittance adjusting film 1000 may be opaque. That is, the background underneath the light transmittance adjusting film 1000 was not seen. According to the drawn line of the film in the figure, the tensile strain is about 0.15 to 0.2.

Referring to FIG. 11C, when the tensile force is removed, the light transmittance of the light transmittance adjusting film may be increased again. This is because the copolymer 200 has good elastic recovery properties and the matrix portion P2 returns to its initial state before the external force is applied. For example, the light transmittance adjusting film 1000 may be transparent. The background underneath the light transmittance adjusting film 1000 was observed again.

The foregoing detailed description is not intended to limit the invention to the disclosed embodiments, and may be used in various other combinations, modifications, and environments without departing from the spirit of the invention. The appended claims should be construed to include other embodiments.

Claims (17)

1. A matrix portion comprising a copolymer and a polymer chain grafted to the copolymer; And

   A polymer derived from a first monomer and comprising a dispersed moiety provided in the matrix portions, wherein the polymer chain is derived from the first monomer,

   Exhibit a first light transmittance while the external force is applied; And

   The light transmittance adjusting film which, when the external force is removed, exhibits a second light transmittance greater than the first light transmittance.
2. The method of claim 1,

   The second light transmittance is a light transmittance control film having a transmittance of 35% to 95% of light in the visible region.
3. The method of claim 1,

   While the external force is applied, voids are provided between the dispersed portion and the matrix portion,

   When the external force is removed, the voids are light transmittance control film.
4. The method of claim 1,

   Wherein said dispersed portion has an initial modulus of elasticity greater than said matrix portion.
5. The method of claim 4, wherein

   Wherein said dispersed portion has an initial modulus of elasticity of 100 to 100,000 times that of said matrix portion.
6. The method of claim 1,

   And a refractive index difference between the refractive index of the matrix portion and the dispersed portion is less than 5%.
7. The method of claim 1,

   The external force is a light transmittance control film comprising a tensile force.
8. The method of claim 1

   The first monomer is a light transmittance control film represented by the following formula (1).

   [Formula 1]

   

   In Formula 1, A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and R1 is hydrogen, halogen, a linear or branched alkyl group having 1 to 8 carbon atoms, or 1 carbon atom. A halogen substituted linear or branched alkyl group of 8 to 8, and R2, R3, and R4 are each independently hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms.
9. The method of claim 8

   The matrix portion is a light transmittance control film represented by the following formula (6A).

   [Formula 6A]

   

   In formula (6A), R11 is represented by the following formula (2B), and R12, R13, and R14 are each independently hydrogen, halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms. R15 may be represented by the following Chemical Formula 6B. R16 may be represented by the following Chemical Formula 6C.

   [Formula 2B]

   

   In Formula 2B, * means a moiety bonded to Si of Formula 6A, and B is a single bond or a linear or branched alkyl group having 1 to 5 carbon atoms, carbonyl group, ester group, acetate group, amide group, or -S- CO-, and R21, R22, and R23 are each independently hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms.

    [Formula 6B]

   

   In formula (6B), * means a moiety bonded to Si in formula (6A), A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and B is a single bond, carbon number Linear or branched alkyl group of 1 to 5, carbonyl group, ester group, acetate group, amide group or -S-CO-, R1 is hydrogen, halogen, linear or branched alkyl group of 1 to 8 carbon atoms, or 1 carbon atom A halogen substituted linear or branched alkyl group of 8 to 8, R 2, R 3, and R 4 are each independently hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms, and R 21, R 22, and R 23 are each independently Hydrogen, halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms, and m6 is an integer selected from 1 to 100.

   [Formula 6C]

   

   In formula (6C), * means a moiety bonded to Si of formula (6A), A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and B is a single bond, carbon number Linear or branched alkyl group of 1 to 5, carbonyl group, ester group, acetate group, amide group or -S-CO-, R1 is hydrogen, halogen, linear or branched alkyl group of 1 to 8 carbon atoms, or 1 to C A halogen substituted linear or branched alkyl group of 8, R 2, R 3, and R 4 are each independently hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms, and R 21, R 22, and R 23 are each independently hydrogen , A halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms, and m7 is an integer selected from 1 to 100.
10. A first monomer; And

    A copolymer comprising a first polymer derived from the second monomer and a second polymer derived from a third monomer,

    The molar ratio of the first polymer and the first monomer in the copolymer is 1: 5 to 1: 100,

    And a molar ratio of the first polymer and the second polymer in the copolymer is 1: 4 to 1: 200.
11. The method of claim 10,

    The first monomer is a light transmittance control film composition represented by the formula (1).

    [Formula 1]

    

    In Formula 1, A1 and A2 are each independently a single bond, oxygen (O), -NH-, or sulfur (S), and R1 is hydrogen, halogen, a linear or branched alkyl group having 1 to 8 carbon atoms, or 1 carbon atom. A halogen substituted linear or branched alkyl group of 8 to 8, and R2, R3, and R4 are each independently hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms.
12. The method of claim 11,

    The first polymer is a light transmittance control film composition comprising a polymerization unit represented by the formula (2A).

    [Formula 2A]

    

    In formula (2A), R11 is represented by formula (2B) below, R12 is hydrogen, halogen, linear or branched alkyl group of 1 to 5 carbon atoms, or substituted or unsubstituted phenyl group of 6 to 13 carbon atoms, m1 is 2 to 50 Is an integer between.

    [Formula 2B]

    

    In formula (2B), B is a single bond or a linear or branched alkyl group having 1 to 5 carbon atoms, carbonyl group, ester group, acetate group, amide group, or -S-CO-, and R21, R22, and R23 are each independently Hydrogen, halogen, or a linear or branched alkyl group having 1 to 5 carbon atoms.
13. The method of claim 12,

    The second polymer is a light transmittance control film composition comprising a polymerization unit represented by the formula (3).

     [Formula 3]

    

    In formula (3), R13 and R14 are each independently hydrogen, halogen, a linear or branched alkyl group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group having 6 to 13 carbon atoms, and m2 is an integer between 10 and 10,000.
14. The method of claim 10,

    The first monomer comprises t -butyl acrylate,

    The copolymer includes a silicone copolymer represented by Formula 4B below, wherein the silicone copolymer has a weight average molecular weight of 5,000 to 500,000,

    The silicone copolymer is a light transmittance control film composition dissolved in the t -butyl acrylate monomer.

    [Formula 4B]

    

    In Formula 4B, the ratio of m1 to m2 is 1: 4 to 1: 200.
15. The method of claim 14,

    The light transmittance control film composition of claim 1, wherein the molar ratio of the t -butyl acrylate monomer to the total molar ratio of the vinyl group contained in the copolymer is 1: 5 to 1: 100.
16. The method of claim 10,

    A light transmittance adjusting film composition further comprising a polymerization initiator.
17. The method of claim 16,

    At least one of the first monomer and the copolymer comprises a vinyl group,

    The polymerization initiator is a light transmittance control film composition of 0.05 to 5 mol% based on the total of the vinyl group.

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