阅读说明：本技术 组合物、聚合物分散液晶、薄膜和电子设备 (Composition, polymer dispersed liquid crystal, film and electronic device ) 是由 吴中正 王雷 李辉 侯体波 于 2021-08-30 设计创作，主要内容包括：本申请公开了组合物、聚合物分散液晶、薄膜和电子设备,包括：聚合物单体和液晶,液晶包括高双折射率化合物,液晶中高双折射率化合物的双折射率不小于0.4。由此,可通过该组合物制备具有较高对比度的聚合物分散液晶。(Disclosed are compositions, polymer dispersed liquid crystals, films, and electronic devices comprising: the liquid crystal comprises a high-birefringence compound, and the birefringence of the high-birefringence compound in the liquid crystal is not less than 0.4. Thus, a polymer dispersed liquid crystal having a higher contrast can be prepared by the composition.)

1. A composition for preparing a polymer dispersed liquid crystal comprising:

the liquid crystal display panel comprises a polymer monomer and liquid crystal, wherein the liquid crystal comprises a high-birefringence compound, and the birefringence of the high-birefringence compound in the liquid crystal is not less than 0.4.

2. The composition as claimed in claim 1, wherein said composition further comprises: a photoinitiator comprising benzoin diethyl ether.

3. The composition of claim 2, wherein the polymer monomer comprises an acrylate compound comprising at least one of bisphenol a polyoxyethylene ether methacrylate, polyethylene glycol diacrylate, lauryl methacrylate, and hydroxypropyl methacrylate.

4. The composition of claim 2, wherein the polymer monomer is present in an amount of 45 to 51 parts by weight, the liquid crystal is present in an amount of 48 to 52 parts by weight, the photoinitiator is present in an amount of 1 to 3 parts by weight,

the content of the high-birefringence compound in the liquid crystal is 6-14 parts by weight.

5. The composition of claim 4 wherein the high birefringence compound comprises a biphenyl fluoro-based compound comprising 4- [ difluoro (3,4, 5-trifluorophenoxy) methyl ] -2',3, 5-trifluoro-4 "-propyl-1, 1':4', 1" -terphenyl.

6. The composition of claim 4, wherein the liquid crystal further comprises: 4-pentyloxy-4 ' -cyanobiphenyl, 4-cyano-4 ' -pentylbiphenyl, and 4' -n-pentyl-4-cyanoterphenyl.

7. A polymer dispersed liquid crystal prepared from the composition of any one of claims 1 to 6.

8. A polymer dispersed liquid crystal film, comprising:

two electrically conductive layers, one of which is electrically conductive,

a polymer dispersed liquid crystal layer configured to be controllable by an electric field between the two conductive layers, liquid crystal droplets in the polymer dispersed liquid crystal layer having a diameter of 3.33-4.3 micrometers.

9. The polymer-dispersed liquid crystal film according to claim 8, wherein the polymer-dispersed liquid crystal film has a thickness of 9 to 25 μm.

10. The polymer-dispersed liquid crystal film according to claim 8, wherein the polymer-dispersed liquid crystal film has an on state and an off state, and wherein the polymer-dispersed liquid crystal film has a haze of 2.3 to 2.5% in the on state and a haze of 86.5 to 88% in the off state.

11. The polymer-dispersed liquid crystal film according to claim 8, wherein the polymer-dispersed liquid crystal film has a contrast ratio of not less than 34.

12. An electronic device, comprising:

a housing component having the polymer dispersed liquid crystal film of any one of claims 8 to 11 thereon,

the battery and the mainboard are located in the accommodating space defined by the shell assembly, and the mainboard is electrically connected with the battery.

Technical Field

The present invention relates to the field of electronic devices, and in particular, to a composition for preparing a polymer dispersed liquid crystal, a film and an electronic device.

Background

Since the discovery and introduction of Polymer Dispersed Liquid Crystals (PDLCs) by research team members at kent state university in the united states, PDLCs have been studied indefinitely. At present, PDLC is widely applied to large-area projection screens, buildings, automobile doors and windows, glass curtain walls, indoor partitions and the like. However, when the existing PDLC material is applied to the housing assembly, the effect can be not good. Therefore, it is difficult to apply the conventional polymer dispersed liquid crystal film to a small device such as an electronic device.

Therefore, the current compositions for preparing polymer dispersed liquid crystals, films and electronic devices are still in need of improvement.

Disclosure of Invention

The present application is directed to solving, at least to some extent, one of the technical problems in the related art.

In one aspect of the present invention, the present invention provides a composition for preparing a polymer dispersed liquid crystal comprising: the liquid crystal display panel comprises a polymer monomer and liquid crystal, wherein the liquid crystal comprises a high-birefringence compound, and the birefringence of the high-birefringence compound in the liquid crystal is not less than 0.4. Thus, a polymer dispersed liquid crystal having a higher contrast can be prepared by the composition.

In yet another aspect, the present invention provides a polymer dispersed liquid crystal prepared from the composition as described above. Thus, a polymer dispersed liquid crystal having a higher contrast can be obtained.

In yet another aspect of the present invention, the present invention provides a polymer dispersed liquid crystal film comprising: two conductive layers, a polymer dispersed liquid crystal layer configured to be controllable by an electric field between the two conductive layers, liquid crystal droplets in the polymer dispersed liquid crystal layer having a diameter of 3.33-4.3 micrometers. Thus, a polymer dispersed liquid crystal film having a higher contrast can be obtained.

In yet another aspect of the present invention, the present invention provides an electronic device, including: the shell assembly is provided with the polymer dispersed liquid crystal film, a battery and a mainboard, wherein the battery and the mainboard are positioned in the accommodating space defined by the shell assembly, and the mainboard is electrically connected with the battery. Thus, the electronic equipment with better appearance effect can be obtained.

In the application, a compound with high birefringence, such as a biphenyl fluorine compound, is introduced into liquid crystal, and the liquid crystal with low birefringence is replaced by the liquid crystal with high birefringence in the liquid crystal component, so that the advantages of high clearing point, high birefringence, good low-temperature compatibility and the like of the liquid crystal with high birefringence are utilized, the haze difference of a polymer dispersed liquid crystal layer in a polymer dispersed liquid crystal film before and after electrification is effectively improved, the contrast of the polymer dispersed liquid crystal film is improved, and a consumer has better use experience.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 shows a schematic structural diagram of a polymer dispersed liquid crystal film according to an embodiment of the present invention;

FIG. 2 shows a schematic structural diagram of an electronic device according to an embodiment of the invention;

FIG. 3 shows a schematic microscopic view of a polymer dispersed liquid crystal according to one embodiment of the present invention;

FIG. 4 is a schematic microscopic view showing a polymer dispersed liquid crystal in the related art;

fig. 5 shows a schematic structural diagram of an electronic device housing assembly according to an embodiment of the invention.

Description of reference numerals:

100: a polymer dispersed liquid crystal layer; 200: a conductive layer; 300: polymer dispersed liquid crystal film, 400: a substrate.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

The present application is made based on the findings of the inventors on the following problems:

the inventor finds that the existing PDLC material has poor performance in a small narrow space because the haze data of the polymer dispersed liquid crystal film is spatially attributed, and the effect of the same polymer dispersed liquid crystal film when applied to large-scale equipment such as projection screens, buildings, and automobile doors and windows is different from the effect of the same polymer dispersed liquid crystal film when applied to small-scale equipment such as housing components of electronic equipment, for example, the haze of the same polymer dispersed liquid crystal film in an off state is 95%, which can meet the use requirement, but the haze is only 65% when applied to the housing components. The polymer dispersed liquid crystal film in the related art needs a certain sense of space to achieve a good contrast, and therefore, the polymer dispersed liquid crystal film has many applications in use scenes with a certain space, such as buildings and automobiles. When the polymer dispersed liquid crystal film is zero-to-zero attached to an article to be attached, liquid crystal molecules in the polymer dispersed liquid crystal material in the related technology are mainly low-refractive-index liquid crystals, and the polymer dispersed liquid crystal material has a strong transmittance no matter whether electrified or not, namely, the haze is low, the contrast before and after electrification is extremely low, a user can hardly perceive the change of transparency, and the advantage of the polymer dispersed liquid crystal cannot be embodied. In particular, in the present application, the contrast ratio of the polymer dispersed liquid crystal film is defined as the ratio of the haze of the polymer dispersed liquid crystal film before lighting by applying current to the haze of the polymer dispersed liquid crystal film after lighting by applying current.

In the application, the inventor improves the composition of the composition for forming the polymer dispersed liquid crystal, selects the high birefringence liquid crystal to replace the low refractive index liquid crystal, and utilizes the advantages of the high birefringence liquid crystal, such as high clearing point, high birefringence, good low-temperature compatibility and the like, so as to effectively improve the haze difference of the polymer dispersed liquid crystal layer in the polymer dispersed liquid crystal film before and after power-on, and realize high contrast to be perceived by consumers.

The present application is directed to solving, to some extent, one of the technical problems in the related art.

In one aspect of the present invention, the present invention provides a composition for preparing a polymer dispersed liquid crystal, comprising: the liquid crystal comprises a high-birefringence compound, and the birefringence of the high-birefringence compound in the liquid crystal is not less than 0.4. Since the liquid crystal in the composition includes biphenyl compounds with high birefringence, polymer dispersed liquid crystal with higher contrast can be prepared by the composition.

According to some embodiments of the present invention, the composition of the composition may further include a photoinitiator, the kind of which is not particularly limited, for example, the photoinitiator may include benzoin diethyl ether. Therefore, the polymerization speed of the polymer monomer can be controlled through the photoinitiator, and the size and the appearance of the liquid crystal can be further controlled.

According to some embodiments of the invention, the liquid crystal molecules are free to align within the liquid crystal droplets in the absence of an applied electric field, and all of the liquid crystal droplets are also randomly aligned. Since the liquid crystal molecules are strong optically and dielectrically anisotropic materials, in the closed state, the refractive index is not matched with that of the high polymer, i.e. light is scattered between the liquid crystal molecules and the high polymer and cannot pass through the polymer to disperse the liquid crystal. When an external electric field is applied, the liquid crystal molecules are uniformly arranged in parallel, and when the refractive index of the high polymer is consistent with that of the liquid crystal molecules, light is not scattered between the high polymer and the liquid crystal molecules, and the polymer dispersed liquid crystal is in an on state. Therefore, the kind of the polymer monomer is not particularly limited as long as it can be well dissolved with the liquid crystal, and the refractive index of the polymer formed after the polymer monomer is polymerized is matched with the refractive index after the liquid crystal is electrified and deflected. For example, the polymer monomer may include an acrylate compound, specifically, the polymer monomer may include at least one of bisphenol a polyoxyethylene ether methacrylate, polyethylene glycol diacrylate, lauryl methacrylate, and hydroxypropyl methacrylate, and a high polymer formed by polymerizing the above polymer monomers has a good polarity, a strong degree of crosslinking inside the high polymer, a good degree of surface adhesion and a good cohesion, and a refractive index of the high polymer formed after polymerization matches a refractive index of a liquid crystal after deflection when the liquid crystal is electrified.

According to some embodiments of the present invention, the content of each component in the composition is not particularly limited, for example, the content of the polymer monomer is 45 to 51 parts by weight, the content of the liquid crystal is 48 to 52 parts by weight, and the content of the photoinitiator is 1 to 3 parts by weight. When the content of the polymer monomer is too small, the polymer cannot form an interconnected network, but precipitates from the liquid crystal in the form of particles. As the content of the polymer monomer increases, a polymer network is gradually formed, and as the content of the polymer monomer increases, the gaps of the polymer network structure become smaller. However, the contact area between the polymer and the liquid crystal droplets is increased due to the excessively dense polymer network structure, and thus a larger voltage needs to be applied to change the state of the liquid crystal, and a larger driving saturation voltage is needed. When the content of the polymer monomer, the liquid crystal and the photoinitiator is within the range, a polymer network can be formed, the gaps of the network structure are proper, the liquid crystal dispersed in the polymer network structure has proper particle size, and the polymer dispersed liquid crystal formed by the composition has better electro-optical performance and lower driving voltage.

According to some embodiments of the present invention, the content of the bifluoride-based compound in the liquid crystal is not particularly limited, and for example, the content of the bifluoride-based compound in the liquid crystal may be 6 to 14 parts by weight. When the content of the biphenyl fluorine compound in the high-birefringence compound is less than 6 parts by mass, the haze of the formed polymer dispersed liquid crystal is too low when the electricity is not supplied, and the shielding effect cannot be realized; when the content of the biphenyl fluorine compound in the high birefringence compound is more than 14 parts by mass, the liquid crystal molecules in the formed polymer dispersed liquid crystal are easy to generate crystallization phenomenon, and the use stability of the polymer dispersed liquid crystal film is poor.

According to the embodiment of the present invention, the specific components of the liquid crystal in the liquid crystal component are not particularly limited, and those skilled in the art may select them according to actual situations as long as the aforementioned birefringence requirements can be satisfied. The inventors have found that by incorporating, for example, a biphenyl compound having a fluorine group in the liquid crystal component of the composition, the liquid crystal can be made to have high optical anisotropy, that is, the biphenyl compound having high birefringence can improve the optical anisotropy of the liquid crystal. In particular, the biphenyl fluorine compounds and the compositions thereof can improve the optical anisotropy of the liquid crystal component. More specifically, a liquid crystal composition having a polysubstituted saturated alkyl chain and a terminal double bond, which increase the linear arrangement of the molecules and thus increase the aspect ratio of the liquid crystal molecules, may be used, so that the birefringence value Δ n is increased.

According to some embodiments of the present invention, the birefringence of the high birefringence compound in the liquid crystal is not particularly limited, for example, the birefringence of the high birefringence compound in the liquid crystal may be not less than 0.3. When the birefringence of the high-birefringence compound in the liquid crystal is greater than 0.3, the formed polymer dispersed liquid crystal has large haze change before and after electrification and strong contrast, can effectively realize the appearance effect of the polymer dispersed liquid crystal, and meets the daily use requirement.

According to some embodiments of the present invention, the kind of the high birefringence compound is not particularly limited, for example, the high birefringence compound may include biphenyl fluorine-based compounds, and particularly, biphenyl fluorine-based compounds include 4- [ difluoro (3,4, 5-trifluorophenoxy) methyl ] -2',3, 5-trifluoro-4 "-propyl-1, 1':4', 1" -terphenyl. When the biphenyl fluorine compound is the biphenyl compound, the linear arrangement of molecules can be increased due to the presence of a polysubstituted saturated alkyl chain and a terminal double bond, so that the length-width ratio of liquid crystal molecules can be increased, the optical anisotropy delta n value is increased, and finally the haze change of the formed polymer dispersed liquid crystal before and after electrification is large and the contrast is large.

According to some embodiments of the present invention, the kind of the liquid crystal is not particularly limited, and besides the aforementioned high birefringence compound, the liquid crystal may further include other polymers with lower refractive index, so as to adjust parameters such as refractive index of the liquid crystal as a whole, and to match the refractive index of the polymer to form the polymer dispersed liquid crystal. For example, the liquid crystal may further include: 4-pentyloxy-4 ' -cyanobiphenyl, 4-cyano-4 ' -pentylbiphenyl, and 4' -n-pentyl-4-cyanoterphenyl.

In another aspect of the present invention, the present invention provides a polymer dispersed liquid crystal prepared from the composition. The composition of the polymer dispersed liquid crystal contains biphenyl compounds with high birefringence, so that the liquid crystal compounds can be used for forming polymer dispersed liquid crystal with higher contrast. For ease of understanding, the method for preparing a polymer dispersed liquid crystal by the aforementioned composition will be briefly described: the method comprises the steps of uniformly mixing a polymer monomer and liquid crystal to form a homogeneous solution, initiating polymerization reaction by a photoinitiator through illumination, for example, ultraviolet irradiation, so that the polymer monomer is polymerized to form a high polymer, the molecular weight of the high polymer is gradually increased along with the polymerization reaction, when the high polymer reaches a critical molecular size, the mutual solubility of the high polymer and the liquid crystal is gradually reduced until phase separation occurs to form liquid crystal microdroplets, the size of the liquid crystal microdroplets is gradually increased along with the reaction, and finally the liquid crystal form is fixed by the solidified high polymer. The size and morphology of the liquid crystal droplets depends on the time interval from nucleation of the liquid crystal droplets to completion of the curing of the polymer.

According to some embodiments of the present invention, the size of the liquid crystal droplets in the polymer dispersed liquid crystal may have a better display effect when the size is within a range, for example, the diameter of the liquid crystal droplets in the polymer dispersed liquid crystal should be 3.33-4.3 μm. When the diameter of the liquid crystal microdroplets in the polymer dispersed liquid crystal is within the range, after an external electric field is applied, the difference of the refractive indexes between the liquid crystal microdroplets is small, the consistency of the overall refractive index of the liquid crystal microdroplets is high, the matching degree of the refractive index of the liquid crystal microdroplets and the refractive index of a high polymer is good, the contrast of the polymer dispersed liquid crystal is high, and the display effect is good.

According to some embodiments of the invention, the density of the liquid crystal droplets in the polymer dispersed liquid crystal is limited, for example, the density of the liquid crystal droplets in the polymer dispersed liquid crystal may be greater than 60 per square micron. When the density of the liquid crystal droplets in the polymer dispersed liquid crystal can be more than 60/square micron, the density of the liquid crystal droplets is higher, the distribution in the polymer dispersed liquid crystal is more uniform, the overall display effect of the polymer dispersed liquid crystal is more uniform, and the appearance performance is better.

In still another aspect of the present invention, referring to fig. 1, the present invention provides a polymer dispersed liquid crystal film 300 comprising two conductive layers 200, a polymer dispersed liquid crystal layer 100, the polymer dispersed liquid crystal layer 100 configured to be controllable by an electric field between the two conductive layers 200, liquid crystal droplets in the polymer dispersed liquid crystal layer 100 having a diameter of 3.33-4.3 μm. Thus, the difference in haze before and after energization of the polymer dispersed liquid crystal can be increased, and a high contrast can be realized.

According to some embodiments of the present invention, the composition and position of the conductive layer are not particularly limited, and for example, the conductive layer may be a conductive film; when the conductive layer is a conductive film, the polymer dispersed liquid crystal layer may be located between two conductive films, and the two conductive films may cover a part of the surface of the polymer dispersed liquid crystal layer.

According to some embodiments of the present invention, the thickness of the polymer dispersed liquid crystal film is not particularly limited, and for example, the thickness of the polymer dispersed liquid crystal film may be 9 to 25 micrometers. When the polymer dispersed liquid crystal film is applied to an electronic device, such as a housing assembly, since the electronic device generally has the characteristics of portability and portability, and the thickness of the housing assembly is generally thin, the thickness of the polymer dispersed liquid crystal film should also be matched with the size of the housing assembly, and should not be greatly changed from the size of the original housing assembly. When the thickness of the polymer dispersed liquid crystal film is within the range, the thickness is moderate, the preparation difficulty is low, large-batch preparation is facilitated, the thickness value can be ignored compared with the whole thickness of the electronic equipment, and the portability and the practicability of the electronic equipment are facilitated to be improved.

According to some embodiments of the present invention, in the polymer dispersed liquid crystal layer, liquid crystal molecules form a microphase separation structure with a high polymer in which the liquid crystal molecules are dispersed in the form of droplets. When no electric field is applied to the surface of the polymer dispersed liquid crystal film, the direction vectors of the liquid crystal molecules are randomly distributed under the boundary action of the high polymer, the surface of the polymer dispersed liquid crystal film is in a scattering state, namely an off state, and when the electric field is applied to the polymer dispersed liquid crystal film, the long axes of the liquid crystal molecules are arranged in parallel or vertical to the electric field, and the polymer dispersed liquid crystal film is in a transparent state, namely an on state. The haze ranges of the off-state and the brightness of the polymer dispersed liquid crystal film are not particularly limited, and for example, the haze of the on-state of the polymer dispersed liquid crystal film may be 2.3 to 2.5%, and the haze of the off-state of the polymer dispersed liquid crystal film may be 86.5 to 88%. When the haze of the polymer dispersed liquid crystal film in an on state is more than 2.5%, the transparency of the polymer dispersed liquid crystal film is low after the polymer dispersed liquid crystal film is electrified, and the polymer dispersed liquid crystal film cannot be in a transparent state; when the off-state haze of the polymer dispersed liquid crystal film is less than 86.5%, the haze of the polymer dispersed liquid crystal film is too low when the polymer dispersed liquid crystal film is not electrified, and the polymer dispersed liquid crystal film cannot play a role in shielding.

According to some embodiments of the present invention, the higher the contrast ratio of the polymer dispersed liquid crystal film (haze of the polymer dispersed liquid crystal film before lighting when electricity is applied)/(haze of the polymer dispersed liquid crystal film after lighting when electricity is applied) indicates that the better the display effect of the polymer dispersed liquid crystal film is, the contrast ratio of the polymer dispersed liquid crystal film is not particularly limited, and for example, the contrast ratio of the polymer dispersed liquid crystal film may be not less than 34. When the contrast of the polymer dispersed liquid crystal film is less than 34, the contrast is low, and the user is less likely to perceive the haze change before and after the energization.

In another aspect of the present invention, the present invention provides an electronic device, with reference to fig. 2, including: the housing assembly includes the polymer dispersed liquid crystal film 300, a battery and a motherboard, wherein the battery and the motherboard are located in an accommodating space defined by the housing assembly, and the motherboard and the battery are electrically connected. Therefore, the electronic equipment with better appearance effect can be obtained.

According to some embodiments of the present invention, referring to fig. 5, the housing assembly may include a base 400, the base 400 defining a receiving space of the housing assembly, and the polymer dispersed liquid crystal film 300 being positioned on a side of the base 400 away from the receiving space. Referring to fig. 1, the polymer dispersed liquid crystal film 300 has two conductive layers 200, a polymer dispersed liquid crystal layer 100, and the polymer dispersed liquid crystal layer 100 is configured to be controllable by an electric field between the two conductive layers 200, wherein one conductive layer is located on a side of the polymer dispersed liquid crystal layer close to the substrate, and the other conductive layer 200 is located on a side of the polymer dispersed liquid crystal layer away from the substrate.

According to some embodiments of the present invention, the kind of the base of the housing assembly is not particularly limited, and for example, the base of the housing assembly may be glass.

According to some embodiments of the present invention, the structure of the housing assembly is not particularly limited, for example, a side of the substrate away from the polymer dispersed liquid crystal film may have a texture layer, an ink layer, and other functional film layers, so that the texture layer, the ink layer, and other functional film layers may be displayed when the polymer dispersed liquid crystal film is in an on state, and the texture layer, the ink layer, and other functional film layers may be shielded when the polymer dispersed liquid crystal film is in an off state, so that one housing assembly may exhibit various appearance effects.

According to some embodiments of the present invention, the location of the polymer dispersed liquid crystal film on the housing assembly is not particularly limited, for example, the polymer dispersed liquid crystal film may be directly used as a sub-layer in the membrane structure of the housing assembly, so that the polymer dispersed liquid crystal film may be used to enhance the appearance of the housing assembly without significantly increasing the overall thickness of the electronic device.

According to some embodiments of the present invention, a method of controlling a polymer dispersed liquid crystal film on a housing assembly is not particularly limited, and for example, the method of controlling a polymer dispersed liquid crystal film may include: when a user inputs a control instruction to enable the polymer dispersed liquid crystal film to be in a light-transmitting state, after the processor receives the instruction, the power on of the conducting layers of the polymer dispersed liquid crystal film is controlled to be switched on through the light transmittance of the polymer dispersed liquid crystal film preset by the processor, and the size of an electric field between the two conducting layers in the polymer dispersed liquid crystal film is determined according to the preset light transmittance value; when the voltage between the two conducting layers reaches a preset value, the control voltage is kept stable, when a user inputs a control instruction again to enable the polymer dispersed liquid crystal to be in an off state, the processor receives the instruction and then closes power supply to the two conducting layers, and the polymer dispersed liquid crystal film is in an opaque state. Therefore, a humanized shell assembly control scheme is realized, and the realization scheme is simple and reliable.

The term "electronic device housing" refers to a housing of an electronic device. The specific type of electronic device is not particularly limited by the present application and, for example, the electronic device may be a cell phone, a smart watch, a palm top computer, a notebook computer, a laptop computer, a desktop computer, a portable gaming device, a video recorder, a camera, a pager, or a printer, among others. In particular, the electronic device may be a mobile phone or smart phone (e.g., iPhone (TM) based, Android (TM) based phone), a Portable gaming device (e.g., Nintendo DS (TM), PlayStation Portable (TM), Gameboy Advance (TM), iPhone (TM)), a PDA, a Portable internet device, a music player, and a data storage device, other handheld devices, and a headset such as a watch, an in-ear headphone, a pendant, a headset, etc., and other wearable devices (e.g., a Head Mounted Device (HMD) such as electronic glasses, electronic clothing, an electronic bracelet, an electronic necklace, an electronic tattoo, or a smart watch).

The following embodiments are provided to illustrate the present application, and should not be construed as limiting the scope of the present application. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

Example 1:

preparing a composition according to the formula, uniformly mixing and placing the composition, adopting PET/ITO as a conductive layer, carrying out alkali washing activation treatment on the PET/ITO before use, adopting 40g/L sodium hydroxide solution as washing liquid for alkali washing treatment, wherein the alkali washing time is 10s, and the alkali washing treatment temperature is room temperature.

And coating the uniformly mixed composition on activated PET/ITO, covering a layer of activated PET/ITO on the coated composition, and carrying out ultraviolet irradiation curing on the composition to finally obtain the polymer dispersed liquid crystal film.

Comparative example 1:

comparative example 1 was identical to the examples except that the composition of the liquid crystal in comparative example 1 was as follows.

Comparative example 2:

comparative example 2 was identical to the examples except that the composition of the liquid crystal in comparative example 2 was as follows.

Comparative example 3:

comparative example 3 was identical to the examples except that the composition of the liquid crystal in comparative example 3 was as follows.

Comparative example 4:

comparative example 4 was identical to the examples except that the composition of the liquid crystal in comparative example 4 was as follows.

The polymer dispersed liquid crystal films obtained in the above examples, comparative example 1 to comparative example 4 were subjected to a contrast test by the following methods: the polymer dispersed liquid crystal film is arranged between the detection light source and the signal receiver, and the polymer dispersed liquid crystal film is positioned on one side of the signal receiver close to the detection light source, so that the haze change of the polymer dispersed liquid crystal film in a narrow space can be simulated, and the accuracy of a test result is improved. The detection light source is enabled to continuously emit detection light with constant light intensity, the polymer dispersed liquid crystal film is enabled to be in a powered state and a non-powered state alternately (namely, the on-off state is switched), the signal receiver receives detection light signals, the corresponding haze value of the polymer dispersed liquid crystal film in the on-off state is calculated, and the corresponding contrast value is calculated according to the contrast ratio (the haze of the polymer dispersed liquid crystal film before being powered and lightened)/(the haze of the polymer dispersed liquid crystal film after being powered and lightened). The test results were as follows:

numbering	Haze (%) before electrification	Haze after electrification (%)	Contrast ratio
				Examples	88	2.3	38.26
Comparative example 1	65	2.3	28.26
				Comparative example 2	76	0.4	190
Comparative example 3	80	2	40
				Comparative example 4	95	17	5.59

The test result shows that, referring to fig. 4, the microscopic image of the liquid crystal microdroplets of the polymer dispersed liquid crystal film in the comparative example 1 shows that, because the high-birefringence liquid crystal molecules are lacked in the comparative example 1, the haze before lighting is only 65%, and the shielding requirement of the polymer dispersed liquid crystal film cannot be met, the birefringence of the liquid crystal in the comparative example 2 is only 0.1091, the transmittance of the polymer dispersed liquid crystal film is high, the shielding effect cannot be achieved in the off state, and the haze before and after lighting is relatively low, and the contrast effect is poor; in comparative example 3, the content of polyfluorotriphenyl in the components constituting the liquid crystal is low, the haze of the polymer dispersed liquid crystal film in the off state is only 80%, and the haze in the on state is 2%, although the contrast is high, the haze in the off state is low, and the shielding effect cannot be realized; the content of polyfluoro terphenyl in the components constituting the liquid crystal in comparative example 4 was high, and the formed polymer dispersed liquid crystal film exhibited a crystallization phenomenon, which could not satisfy the basic use requirements of the polymer dispersed liquid crystal film.

Referring to fig. 3, a microscopic view of liquid crystal droplets of the polymer dispersed liquid crystal film in example 1 shows that, specifically, the polymer dispersed liquid crystal film in example 1 has a haze of 88% before being energized, is in an off state, and can achieve a shielding effect, and has a haze of 2.3% after being energized, and is in an on state, and can achieve a light transmitting effect, and has a contrast ratio of 38.26, which meets the contrast requirement required when the polymer dispersed liquid crystal film is disposed on a housing component of an electronic device. Since the polymer dispersed liquid crystal film in embodiment 1 is added with the liquid crystal molecules with high birefringence, the haze difference of the polymer dispersed liquid crystal layer in the polymer dispersed liquid crystal film before and after power-on is effectively improved by utilizing the advantages of high clearing point, high birefringence, good low-temperature intermiscibility and the like of the high birefringence liquid crystal, so that the off-state shielding effect and the on-state light transmission effect are both improved, and the high contrast is realized to be perceived by consumers.

In the description of the present invention, the terms "upper", "lower", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention but do not require that the present invention must be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description herein, references to the description of "one embodiment," "another embodiment," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.