Laminated product and manufacturing method therefor

Abstract

The present application relates to a laminated product and a manufacturing method therefor. The laminated product comprises: first and second substrates which are arranged opposite to each other; an active system arranged between the first and second substrates, wherein the active system comprises third and fourth substrates which are arranged in a stacked manner, and a light modulation layer located between the third and fourth substrates, and the light modulation layer has certain fluidity; and a first intermediate layer located between the active system and the first substrate, and a second intermediate layer located between the active system and the second substrate, wherein the first intermediate layer and the second intermediate layer are made of hot melt adhesive. The thickness variation range of the light modulation layer in the active system is less than half of the wavelength of visible light.

Description

A laminate and method of making the same

[0001] This application is based on and claims priority to Chinese patent application No. CN202410714216.8, filed on June 4, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of optoelectronic technology, and in particular to a laminate and method of making the same. BACKGROUND

[0003] In the door and window glass products, the traditional solutions for privacy and partial solutions for energy consumption increase include mechanical devices such as curtains, shutters, etc. In recent years, there are also hollow glass, Low E coated film and other product technologies to solve the increase in energy consumption. In recent decades, people have conducted a large amount of research on so-called light-adjustable glass that can directly adjust the propagation of light, and the product technology has become increasingly mature. Light-adjustable glass is increasingly widely used in the fields of construction and transportation.

[0004] Existing light-adjustable technologies mainly include three categories: electrochromic, suspended particle technology, and liquid crystal light-adjustable technology. Electrochromic technology (EC) has excellent solid device characteristics, but its color-changing speed is several minutes or even tens of minutes, and the minimum light transmittance or colored state cannot protect privacy in the indoor scene when the external ambient light is relatively dark. Strict requirements for device uniformity and purity result in low product yield and short product life. The suspended particle (SPD) technology is currently in a high colored state when powered off, but similar to electrochromic glass, it still cannot play a role in privacy protection. At the same time, the SPD technology is in a light-blocking state when powered off, which does not meet the requirement of switching to a safe transparent state when powered off.

[0005] And liquid crystal dimming technology because of the overall industrialization of flat panel display technology has made great progress. The conventional polymer dispersed liquid crystal (PDLC) has very excellent privacy protection characteristics, its products are widely used in interior decoration, indoor partition and other fields. But including trans PDLC technology, because of its limited viewing angle range, not clear enough in transparent state, almost no any solar radiation energy regulation is blocked in the market application. In recent years, new type of dimming technology, bistable liquid crystal dimming device has great improvement compared with PDLC technology. However, similar to PDLC technology, bistable liquid crystal dimming glass for solar radiation energy regulation is minimal. Dye liquid crystal dimming technology is due to the use of its molecular dichroism light absorption characteristics, a single dye liquid crystal device only for one kind of polarized light regulation, resulting in the need for polarization direction of double piece of dye liquid crystal, or a piece of polarizer plus a dye liquid crystal device can be for natural light depth regulation. Thus the dynamic range of single dye liquid crystal device dimming is narrower than EC, SPD technology, and the dynamic range of solar radiation energy is also smaller, and the cost is even higher. At the same time, similar to EC and SPD dimming technology, dye liquid crystal dimming glass cannot play the role of privacy protection in the dark night environment.

[0006] Therefore, the applicant puts forward a kind of liquid crystal dimming device in the Chinese patent application with application number CN202111232990.8 and the name of "a kind of liquid crystal dimming device". The liquid crystal layer of the liquid crystal dimming device includes liquid crystal composition and dichroic dye. Further, the liquid crystal composition includes nematic liquid crystal composition, chiral compound and bimesogen compound. The liquid crystal molecule arrangement state exists at least two stable states that remain basically stable after voltage removal, at least one of which is a transmission state, and the collimated transmission light flux of visible light incident on the liquid crystal layer is greater than the scattered light flux; At least one is a shielding state, and the collimated transmission light flux of visible light incident on the liquid crystal layer is less than the collimated transmission light flux of the transmission state. Thus, the single box dimming device realizes the functions of privacy protection and light-dark adjustment at the same time, and the dimming device has at least two stable states that remain stable after voltage removal. Only pulse voltage switching is required, no voltage maintenance is required, and the power consumption is low. In addition, the contrast ratio of the conventional dye liquid crystal single box is better than that of the conventional dye liquid crystal single box, and it also has good energy saving effect.

[0007] With the booming development of the automotive field, the industry has proposed the demand for safety glass that can achieve light adjustment function. According to the relevant vehicle glass safety technology regulations such as the Chinese national standard GB9656-2021 and the United Nations Economic Commission ECE R43 regulations, laminated safety glass can be applied to any part of the vehicle. The so-called laminated safety glass is made of two or more layers of glass glued with one or more layers of interlayer.

[0008] In the efforts to add light adjustment function to laminated safety glass products, people try to embed light adjustment devices between the multiple interlayers of laminated safety glass. For example, the patent specification with publication number CN1822951A and the name "Window glass with functional safety" proposes an electrochromic (EC) laminated safety glass, which includes two hard substrates, a polymer film (made of PVB or EVA materials) between them, and an electrochromic device between the polymer film. Since the materials of each layer of the electrochromic device can be in a solid form, when it is placed between the polymer film and laminated and pressed on both sides of the hard substrate, the electrochromic device in a full solid form is not easy to produce thickness unevenness, which can avoid or reduce obvious visual defects (mura).

[0009] But as the above-mentioned disadvantages of electrochromic devices, people tend to use liquid crystal light adjustment devices or SPD light adjustment devices with better light adjustment performance as light adjustment devices in laminated safety glass. The characteristics of such devices are that they have light adjustment materials with certain fluidity in the light adjustment function layer. Therefore, experiments have found that in the process of making laminated safety glass products using such light adjustment devices, the light adjustment devices are prone to local deformation or thickness unevenness, and then obvious visual defects (mura) appear. This problem is more obvious when making laminated safety glass with single or double curved surfaces such as roof glass or front windshield glass, because the light adjustment devices used in such curved surface laminated safety glass are usually flexible light adjustment devices, and flexible light adjustment devices are more prone to deformation and thickness unevenness in the process of making laminated safety glass products.

[0010] In order to solve this problem, the patent specification with publication number CN115835961A and the name "Laminated window glass with functional film" proposes to further increase the OCA transparent adhesive material layer between the light adjustment device and the interlayer (such as PVB). Although this can alleviate the problem of visual appearance, it increases the complexity of the product and the manufacturing process and the cost, and this solution has strict requirements for the thickness and hardness of the OCA transparent adhesive material layer.

[0011] Another solution is disclosed in the patent specification CN116794871 entitled "Light modulation device and manufacturing method", which proposes a scheme of forming a hollow box structure by pasting a flexible light modulation film, a first transparent plate and a second transparent plate through a frame, then forming two hollow cavities between the flexible light modulation film and the first transparent plate and between the flexible light modulation film and the second transparent plate, and forming a glue pouring port communicating with the two hollow cavities, and then pouring liquid optical glue into the hollow cavities through the glue pouring port to form a first glue layer and a second glue layer. This is a so-called "glue pouring" process, which has the disadvantages of being not conducive to the production of large-size products, being prone to air bubbles, and having high manufacturing cost.

[0012] In summary, there is an urgent need in the industry to provide a laminated glass product with excellent light modulation performance, no obvious visual defects and low manufacturing cost. SUMMARY

[0013] To solve the above problems, the present application provides a laminated product and a manufacturing method thereof, which has excellent light modulation performance, low manufacturing cost and no obvious visual defects.

[0014] To achieve the above-mentioned purpose, the present application provides a laminated product, comprising:

[0015] a first substrate and a second substrate arranged oppositely;

[0016] an active system arranged between the first and second substrates, the active system comprising a third substrate and a fourth substrate arranged in a stack, and a light modulation layer located between the third and fourth substrates, the light modulation layer having a certain flowability;

[0017] a first intermediate layer located between the active system and the first substrate, and a second intermediate layer located between the active system and the second substrate, the first and second intermediate layers being made of hot melt adhesive;

[0018] the thickness of the light modulation layer in the active system varies in a range less than 1 / 2 of the wavelength of visible light.

[0019] In a preferred mode, the variable optical transformation function of the light modulation layer changes according to the electric field, thermal energy, pressure or magnetic field applied thereon.

[0020] In a preferred mode, the variable optical transformation function of the light modulation layer includes transmission, absorption, reflection, diffraction and / or scattering.

[0021] In a preferred mode, the light modulation layer includes a dye-free liquid crystal layer, a liquid crystal layer with dichroic dye added, or a suspended particle material layer.

[0022] In a preferred mode, the liquid crystal layer includes nematic liquid crystal, cholesteric liquid crystal, smectic liquid crystal or columnar liquid crystal.

[0023] In a preferred mode, the liquid crystal layer further comprises a polymer network for stabilizing the cholesteric phase liquid crystal.

[0024] In a preferred mode, the active system as a whole is flexible.

[0025] In a preferred mode, at least one of the third and fourth substrates in the active system is a flexible substrate.

[0026] In a preferred mode, the flexible substrate is made of PET, PC, or ultra-thin glass.

[0027] In a preferred mode, the hot-melt adhesive comprises a thermoplastic material or a thermosetting material.

[0028] In a preferred mode, the thermoplastic material comprises polyvinyl butyral resin PVB or ionic interlayer SGP.

[0029] In a preferred mode, the thermosetting material comprises ethylene-vinyl acetate copolymer EVA or polyolefin elastomer POE.

[0030] In a preferred mode, the active system comprises an optically transformable functional area and a non-optically transformable functional area.

[0031] In a preferred mode, the non-optically transformable functional area is an area in the active system where a frame adhesive is provided, the frame adhesive being used to bond the third substrate and the fourth substrate and to seal the material of the light modulation layer together with the third substrate and the fourth substrate.

[0032] In a preferred mode, the light modulation layer comprises a liquid crystal layer, the liquid crystal layer comprising a liquid crystal composition and a dichroic dye, the liquid crystal composition comprising a nematic liquid crystal composition, a chiral compound, and a bimesogenic compound.

[0033] In a preferred mode, the liquid crystal layer changes the arrangement state of the liquid crystal molecules in the liquid crystal layer under an applied electric field, the arrangement state of the liquid crystal molecules having at least two stable states that remain substantially stable after the electric field is removed, at least one of the stable states being a transparent state, the transparent state having a collimated transmitted light flux greater than a scattered light flux for visible light incident on the liquid crystal layer, and at least one of the stable states being a shielding state, the shielding state having a collimated transmitted light flux less than the collimated transmitted light flux of the transparent state for visible light incident on the liquid crystal layer.

[0034] In one preferred embodiment, the bimesogenic compound is a liquid crystal compound comprising two mesogenic groups in the molecule, having a structure of R1-MG1-X-MG2-R2, wherein R1, R2 each independently represents -H, -F, -Cl or an alkyl group having 1-25 carbon atoms, wherein one or more H atoms in the alkyl group having 1-25 carbon atoms can each independently be replaced by a halogen, and one or more non-adjacent -CH2- in the alkyl group having 1-25 carbon atoms can each independently be replaced by -O-, -CH=CH-, -CH=CF- or -CF=CF-; MG1 and MG2 each independently represents a mesogenic group; X is a straight chain or branched alkylene group having 3-40 carbon atoms, wherein one or more -CH2- in the straight chain or branched alkylene group having 3-40 carbon atoms can each independently be replaced by -O-, -CH(F)-, -CH(Cl)- or -CH=CH- in such a way that two -O- are not adjacent to each other or two double bonds are not adjacent to each other; and the bimesogenic compound accounts for 10wt%-50wt% of the liquid crystal composition.

[0035] In one preferred embodiment, the liquid crystal layer can be in at least three states: high transparency, low haze state, low coloration, low haze state and high coloration, high haze state, for visible light and near infrared light incident thereon.

[0036] In one preferred embodiment, the first intermediate layer and the second intermediate layer are made of different materials.

[0037] In one preferred embodiment, the first intermediate layer and the second intermediate layer are made of different materials.

[0038] Another aspect of the present application also provides a method for making a laminated article, comprising:

[0039] providing a first substrate, a second substrate, and an active system, the active system comprising a third and a fourth substrate arranged in a stack, and a light modulation layer between the third and fourth substrates, the light modulation layer having a certain flowability, arranging a first intermediate layer between the first substrate and the active system, and a second intermediate layer between the second substrate and the active system, the first and second intermediate layers being made of hot melt glue,

[0040] press-bonding the first substrate, the first intermediate layer, the active system, the second intermediate layer and the second substrate together, and making the thickness variation range of the light modulation layer in the active system less than 1 / 2 of the wavelength of visible light.

[0041] In a preferred mode, the pressing together of the first substrate, the first intermediate layer, the active system, the second intermediate layer and the second substrate comprises: a pressing process controlled in the time-space dimension, by which the first substrate, the first intermediate layer, the active system, the second intermediate layer and the second substrate are pressed together.

[0042] In a preferred mode, the pressing process controlled in the time-space dimension comprises: a pressing process controlled in correspondence with time and / or area.

[0043] In a preferred mode, the pressing process controlled in correspondence with time and / or area comprises:

[0044] Control of the vacuum degree of the pressing environment and / or the heating melting temperature in correspondence with time / area.

[0045] In a preferred mode, the active system comprises an optical transformation functional area and a non-optical transformation functional area.

[0046] In a preferred mode, the non-optical transformation functional area is an area in which a frame glue is arranged in the active system, the frame glue is used to bond the third and fourth substrates and jointly seal the material of the light modulation layer with the third and fourth substrates.

[0047] The application has the beneficial effect of providing a laminated product and a manufacturing method thereof, the laminated product is manufactured by laminating the first and second substrates, the intermediate layers and the active system comprising a light modulation layer with a certain fluidity. The product is compatible with various curved or planar shaped first and second substrates, so that the laminated product can be applied to scenarios such as automotive glass that have curved shape characteristics requirements. At the same time, by limiting the thickness variation range of the light modulation layer to be less than 1 / 2 of the wavelength of visible light, the mura phenomenon of the laminated product can be effectively alleviated.

[0048] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the application claimed. BRIEF DESCRIPTION OF DRAWINGS

[0049] The accompanying drawings are included to provide a further understanding of the application, and are incorporated and constitute part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

[0050] FIG. 1 is a schematic structural diagram of a laminated product according to an embodiment of the application;

[0051] FIG. 2A is a schematic cross-sectional view of an active system showing the internal structure;

[0052] FIG. 2B is a top view of the active system;

[0053] FIG. 3 is a schematic view of a structure of layers of a laminate before being press-bonded according to another embodiment of the present application;

[0054] FIG. 4 is a schematic view of a structure of layers of a laminate before being press-bonded according to another embodiment of the present application;

[0055] FIG. 5A is a schematic view of a structure of layers of a laminate before being press-bonded according to another embodiment of the present application;

[0056] FIG. 5B is a schematic view of a cross-section of the structure of layers of FIG. 5A;

[0057] FIG. 6 is a flowchart of a method of manufacturing a laminate according to another embodiment of the present application. DETAILED DESCRIPTION

[0058] Reference will now be made in detail embodiments of the present application, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[0059] The shapes, sizes, ratios, angles and numbers disclosed in the accompanying drawings for describing embodiments of the present application are only examples and thus the present application is not limited to the illustrated details. Like reference numerals refer to like elements throughout. In the following description of the present application, detailed descriptions of functionally or structurally similar parts, which are determined to make the gist of the present application unnecessarily ambiguous, will be omitted.

[0060] In the case where "include", "have" and "comprise" are used in the present specification, other parts can be added unless "only" is used. The singular form can include the plural form as well unless it is explicitly described otherwise.

[0061] In explaining an element, the element is explained as including an error range even if not explicitly described.

[0062] In the description of embodiments of the present application, when a structure (for example, an electrode, a line, a wiring, a layer, or a contact) is described as being formed on an upper portion of another structure, a lower portion of another structure, or on or under another structure, this description should be understood to include a case in which the structures contact each other, in addition to a case in which a third structure is disposed therebetween.

[0063] In describing a time relationship, for example, when a time sequence is described as "after", "subsequently", "next", and "before", unless "just" or "immediately" is used, a discontinuous case can be included.

[0064] It should be understood that, although the terms“first,”“second,” etc. can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present application.

[0065] The“X-axis direction,”“Y-axis direction,” and“Z-axis direction” should not be interpreted only by geometric relationship of being merely perpendicular to each other, but can have a broader directionality within a range in which the elements of the present application can function.

[0066] The term“at least one of’ should be understood as including any and all combinations of one or more of the associated listed items. For example, the meaning of“at least one of a first item, a second item, and a third item” represents a combination of all of the items from the first item, the second item, and the third item, as well as a combination of two or more of the first item, the second item, and the third item.

[0067] The features of various embodiments of the present application can be partially or wholly connected or combined with each other, and can be inter-operable in various ways and in a technology-driven manner, as can be fully understood by those skilled in the art. Embodiments of the present application can be executed independently of each other, or can be executed together in a mutually dependent relationship.

[0068] Hereinafter, example embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0069] FIG. 1 illustrates a schematic view of a laminate provided by a first embodiment of the present application, which includes a first substrate 101 and a second substrate 101’ disposed opposite each other, and an active system 103 disposed between the first substrate 101 and the second substrate 101’.

[0070] The first substrate 101 can be a rigid substrate or a flexible substrate. The second substrate 101’ can be a rigid substrate or a flexible substrate. The material of the rigid substrate can be selected from one or more of glass, tempered glass, Low-e glass, and special glass having a barrier against electromagnetic wave radiation.

[0071] Figure 2A shows a cross-sectional schematic view of the active system 103, which can exhibit internal structure, and Figure 2B is a top view of the active system 103 in Figure 2A. The active system 103 includes a third substrate 1031 and a fourth substrate 1031', which are arranged in a stack, and a light modulation layer 1032 between the third substrate 1031 and the fourth substrate 1031'. The light modulation layer 1032 has a certain fluidity. In practice, in order to seal the material in the light modulation layer, a frame glue 1033 can also be provided. The frame glue 1033 is used to bond the third substrate 1031 and the fourth substrate 1031', and together with the third substrate 1031 and the fourth substrate 1031' to jointly seal the material in the light modulation layer 1032.

[0072] As shown in Figure 1, the laminated product further includes a first intermediate layer 102 between the active system 103 and the first substrate 101, and a second intermediate layer 102' between the active system 103 and the second substrate 101'. The first intermediate layer 102 and the second intermediate layer 102' are made of hot melt glue.

[0073] In optional embodiments, the hot melt glue can include thermoplastic materials or thermosetting materials. The thermoplastic materials can include PVB (Polyvinyl Butyral) or SGP (Sentry Glas Plus, ionic interlayer film). The thermosetting materials can include EVA (Ethylene Vinyl Acetate) or POE (Polyolefin Elastomer). The POE in a narrow sense is made of metallocene-catalyzed ethylene-alpha olefin copolymer.

[0074] The laminated product in the present embodiments can be a laminated glass product in practice. The active system can be a system whose optical transformation function for incident light can change with external excitation.

[0075] At least one of the first substrate 101 and the second substrate 101' can be a rigid transparent glass substrate. At least one of the first substrate 101 and the second substrate 101' can be planar or curved. The curved surface can be a single curved surface or a double curved surface.

[0076] The optical conversion function of the light modulation layer 1032 in the active system 103 is changed by any one of physical fields, such as an electric field, a thermal energy, a pressure, or a magnetic field, applied thereto. When the physical field applied to the light modulation layer 1032 is an electric field, an electrode layer (not shown in FIG. 2A) can be provided on at least one of the upper and lower sides of the light modulation layer 1032, and the electrode layer can be provided between the light modulation layer 1032 and the third substrate 1031 or the fourth substrate 1031'. The material of the electrode layer can include, but is not limited to, silver oxide (AgO or Ag2O or Ag2O3), aluminum oxide (e.g., Al2O3), tungsten oxide (e.g., WO2 or WO3 or W2O3), magnesium oxide (e.g., MgO), molybdenum oxide (e.g., MoO3), zinc oxide (e.g., ZnO), tin oxide (e.g., SnO2), indium oxide (e.g., In2O3), chromium oxide (e.g., CrO3 or Cr2O3), antimony oxide (e.g., Sb2O3 or Sb2O5), titanium oxide (e.g., TiO2), nickel oxide (e.g., NiO), copper oxide (e.g., CuO or Cu2O), vanadium oxide (e.g., V2O3 or V2O5), cobalt oxide (e.g., CoO), iron oxide (e.g., Fe2O3 or Fe3O4), niobium oxide (e.g., Nb2O5), indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide doped with aluminum (ZAO), zinc aluminum oxide (TAO), or antimony zinc oxide (ATO).

[0077] The variable optical conversion function of the light modulation layer 1032 includes at least one or any combination of various optical conversion functions such as transmission, absorption, reflection, diffraction, and / or scattering.

[0078] The light modulation layer 1032 can include a liquid crystal layer without dichroic dye, a liquid crystal layer with dichroic dye, or a suspended particle (SPD) material layer. The dichroic dye can achieve absorption of incident light and anisotropy of absorption coefficient.

[0079] The liquid crystal layer herein can include a nematic liquid crystal, a cholesteric liquid crystal, a smectic liquid crystal, or a columnar liquid crystal.

[0080] As a specific example of the light modulation layer 1032, the light modulation layer 1032 can include a cholesteric liquid crystal without a polymer network stabilization.

[0081] With the variable optical conversion function of the light modulation layer 1032, the light modulation layer 1032 can achieve a plurality of working states of different optical conversion functions. For example, at least two of the following working states can be included but are not limited thereto:

[0082] State A: white non-transparent state, which can be achieved by scattering the incident light, in one example, by the focal conic state of the cholesteric liquid crystal. Specifically, the focal conic state can be achieved by applying a low electric field to the cholesteric liquid crystal.

[0083] State B: black non-transparent state, which can be achieved by scattering and absorbing the incident light, in one example, by the focal conic state of the cholesteric liquid crystal with added dichroic dye. Specifically, the focal conic state can be achieved by applying a low electric field to the cholesteric liquid crystal, which in turn induces a random alignment of the dichroic dye, thereby resulting in strong absorption of the incident light.

[0084] State C: high transparent state, which can be achieved by a high transmittance state with minimized scattering and absorption of the incident light, in one example, by the homeotropic state of the cholesteric liquid crystal. Specifically, the homeotropic state can be achieved by applying a high enough electric field to the cholesteric liquid crystal. When the cholesteric liquid crystal is in the homeotropic state, even if dichroic dye is added, the dye still aligns perpendicularly to the liquid crystal molecules, resulting in minimized absorption of the incident light.

[0085] State D: reflective state, which can be achieved by reflecting light of specific wavelengths, in one example, by the planar state of the cholesteric liquid crystal. Specifically, the planar state can be achieved by applying a high enough electric field to the cholesteric liquid crystal to switch it to the homeotropic state, and then removing the applied electric field to allow the cholesteric liquid crystal to relax to the planar state.

[0086] States A, B, and D can be maintained stably without the application of an electric field.

[0087] As a preferred embodiment, the light modulation layer 1032 can include a liquid crystal layer, which includes a liquid crystal composition and a dichroic dye, the liquid crystal composition including a nematic liquid crystal composition, a chiral compound, and a bimesogenic compound. The liquid crystal layer changes the alignment state of the liquid crystal molecules in the liquid crystal layer under the application of an electric field, and the alignment state of the liquid crystal molecules has at least two stable states that remain substantially stable after the electric field is removed, at least one of the stable states being a transmissive state in which the collimated transmitted light flux of visible light incident on the liquid crystal layer is greater than the scattered light flux, and at least one of the stable states being a shielding state in which the light incident on the liquid crystal layer is both absorbed and scattered. By driving the above-mentioned liquid crystal layer, at least three states can be obtained, such as a low tint, low haze state; a high tint, high haze state; and a high clarity, low haze state.

[0088] The high clarity, low haze state can be obtained by continuously applying a first electric field to the liquid crystal layer, so that the liquid crystal molecules in the liquid crystal layer are arranged substantially perpendicular to the third and fourth substrates. The low coloration, low haze state is obtained by applying a second electric field to the liquid crystal layer, so that the liquid crystal molecules in the liquid crystal layer are arranged substantially parallel to the third and fourth substrates and have a certain helical structure. The high coloration, high haze state can be obtained by applying a third electric field to the liquid crystal layer, at which time the liquid crystal molecules in the liquid crystal layer are arranged in a random focal conic state.

[0089] The first electric field can be an electric field obtained by applying a continuous voltage, for example, an electric field obtained by applying an alternating voltage. The second and third electric fields can be electric fields obtained by applying a pulsed voltage, for example, electric fields obtained by applying an alternating pulsed voltage.

[0090] The high clarity, low haze state can have a transmittance of not less than 30% and a haze of not more than 5%. The low coloration, low haze state can have a transmittance of not more than 50% and a haze of not more than 10%. The high coloration, high haze state can have a transmittance of not more than 40% and a haze of not less than 60%.

[0091] The transmittance of the high clarity, low haze state and the low coloration, low haze state can be adjusted according to the composition and concentration of the added dichroic dye, and the ratio of the transmittance of the high clarity, low haze state to the low coloration, low haze state for incident light of a specific wavelength or wavelength range can be greater than 2: 1.

[0092] The liquid crystal composition described above is a guest-host type cholesteric liquid crystal composition. The so-called guest-host type cholesteric liquid crystal composition is a GH type cholesteric liquid crystal material formed by adding dichroic dye as a guest to a cholesteric liquid crystal as a host. In the guest-host mode, the arrangement state of the liquid crystal molecules is changed by applying different voltages, and the optical properties of the cholesteric liquid crystal are exhibited. At the same time, the dichroic dye molecules are also oriented with the liquid crystal orientation, and the absorption anisotropy of the dichroic dye molecules is exhibited.

[0093] The chiral compound can be a chiral liquid crystal material, and the chiral compound accounts for 0.01wt%-30wt% of the liquid crystal composition; the chiral compound can adjust the helical pitch P of the cholesteric phase liquid crystal, and the helical pitch P can be adjusted by selecting a chiral compound with a different HTP value or adjusting the concentration of the chiral compound according to the formula P=1 / (HTP*c), wherein HTP is the helical twist constant, and c is the concentration of the chiral compound; the helical pitch P affects the Bragg reflection wave band of the planar state, and according to the solar spectrum, in order to obtain a higher difference in the solar heat gain coefficient between the planar state and the vertical state, the Bragg reflection wave band is generally adjusted to the visible and near-infrared region where the solar radiation energy is relatively strong; the helical pitch P also affects the haze, and a certain d / P value (d is the thickness of the liquid crystal layer) needs to be controlled to obtain a relatively high haze in the haze state, however, for a general chiral nematic liquid crystal, a high d / P value is easy to cause defects in the planar state, resulting in a high and uneven haze in the planar state, and the addition of the bimesogenic compound can effectively solve this problem.

[0094] The bimesogenic compound is an elastic constant regulator, and after being added to the chiral nematic liquid crystal, a relatively high splay elastic constant K11, a relatively low bend elastic constant K33, and a relatively low flexoelectric coefficient K22 can be obtained; the driving voltage of the liquid crystal molecules from an arbitrary state to the vertical state is proportional to the square root of K22, so a relatively low K22 can obtain a relatively low driving voltage in the vertical state; in addition, when the liquid crystal molecules recover from the vertical state to the planar state, the helical pitch changes from infinity to a natural helical pitch, at this time P'=K33 / K22*P, when K33≈K22, the liquid crystal molecules can quickly recover from the vertical state to the planar state, reaching a perfect planar state with extremely small haze.

[0095] As a preferred embodiment, the above-mentioned bimesogenic compound can be a liquid crystal compound containing two mesogenic groups in the molecule, and the structure is R1-MG1-X-MG2-R2;

[0096] wherein R1, R2 each independently represents -H, -F, -Cl, or an alkyl group having a carbon number of 1 to 25, as further preferred embodiments, one or more H atoms in the alkyl group having a carbon number of 1 to 25 can each independently be substituted with a halogen, one or more non-adjacent -CH2- in the alkyl group having a carbon number of 1 to 25 can each independently be replaced with -O-, -CH=CH-, -CH=CF- or -CF=CF-; MG1and MG2each independently represents a mesogenic group; X is a straight chain or branched alkylene group having a carbon number of 3 to 40, as further preferred embodiments, one or more -CH2- in the straight chain or branched alkylene group having a carbon number of 3 to 40 can each independently be replaced with -O-, -CH(F)-, -CH(Cl)- or -CH=CH- in such a way that two -O- are not adjacent to each other or two double bonds are not adjacent to each other; the bimesogenic compound accounts for 10wt%-50wt% of the liquid crystal composition.

[0097] The active system 103 as a whole can have a certain flexibility, that is, the active system 103 can be made into a flexible device. To this end, at least one layer of the third substrate 1031 and the fourth substrate 1031' of the active system 103 is a flexible substrate. The flexible substrate can be selected from at least one of PET film, PI film, PTFE film, PP film, PC film, PVC film, PE film, PS film, PA film, PEN film, PMMA film, PBT film, and ultrathin glass, but the present application is not limited thereto.

[0098] The active system 103 can be divided into an optical conversion functional area 103A and a non-optical conversion functional area 103B according to function. In FIGS. 2A and 2B, the optical conversion functional area 103A is located in the central region of the active system 103, and the non-optical conversion functional area 103B is located in the edge region of the active system 103. Those skilled in the art should understand that in practice, the shape and positional relationship of the optical conversion functional area 103A and the non-optical conversion functional area 103B can also be other implementations, for example, the non-optical conversion functional area 103B "isolates" the optical conversion functional area 103A into multiple areas (which can be arranged in a grid matrix shape), or isolates the optical conversion functional area 103A into multiple areas forming a certain pattern. The non-optical conversion functional area can refer to an area in which optical conversion function is not modulated, for example, an area in which a frame glue 1033 is provided.

[0099] In the manufacturing process of the laminated product in the embodiment, during the heating and pressing of the first substrate 101, the first intermediate layer 102, the active system 103, the second intermediate layer 102', and the second substrate 101', the first intermediate layer 102 and the second intermediate layer 102' are heated and melted to have a certain fluidity, at this time, the uniformity of the thickness of the active system 103 (i.e. flatness) has a certain degree of requirement, otherwise, the first intermediate layer 102 and the second intermediate layer 102' after solidification exist local thickness unevenness, which will lead to the unevenness of the final thickness distribution of the active system 103, and produce the unevenness of visual effects such as brightness and color, that is, mura phenomenon. Therefore, the inventors found through a large number of experiments that when the thickness variation range of the light modulation layer in the active system in the finally obtained laminated product is less than 1 / 2 of the wavelength of visible light, the mura phenomenon can be effectively alleviated. The 1 / 2 of the wavelength of visible light here can be located in the closed interval of 200nm-350nm.

[0100] More preferably, the thickness variation range of the light modulation layer can be less than 1 / 4 of the wavelength of visible light, and the 1 / 4 of the wavelength of visible light here can be located in the closed interval of 100nm-175nm.

[0101] In the manufacturing results of the laminated product shown in the above FIG. 1 and FIG. 2A, the size of the active system 103 is basically the same as the size of the first substrate 101 and the second substrate 101'.

[0102] In another alternative example, in order to seal the active system more fully in the entire laminated product, avoiding the active system from being affected by the external environment and losing effectiveness, the size of the active system can be designed to be smaller than the size of the first substrate 101 and the second substrate 101'. As shown in another example in FIG. 3, a schematic diagram of the layer structure of the laminated product before the pressing bonding. In this example, the laminated product still includes the oppositely arranged first substrate 101 and the second substrate 101', and the active system 103' arranged between the first substrate 101 and the second substrate 101', and further includes the first intermediate layer 102 between the active system 103' and the first substrate 101, and the second intermediate layer 102' between the active system 103' and the second substrate 101'. The first intermediate layer 102 and the second intermediate layer 102' are made of hot melt adhesive. The active system 103' includes the third substrate 1031 and the fourth substrate 1031' arranged in a stack, and the light modulation layer 1032 between the third substrate 1031 and the fourth substrate 1031'. The light modulation layer 1032 has a certain fluidity. In practice, in order to seal the material in the light modulation layer, a frame adhesive 1033 can also be provided. The frame adhesive 1033 is used to bond the third substrate 1031 and the fourth substrate 1031', and together with the third substrate 1031 and the fourth substrate 1031' to seal the material in the light modulation layer 1032. As can be seen from FIG. 3, the overall size of the active system 103' is smaller than the size of the first substrate 101 and the second substrate 101', and therefore there is a sealing material layer 106 in the peripheral area of the edge of the active system 103'. The sealing material layer 106 can be formed by a part of the intermediate layer 102 and 102' originally in the intermediate layer 102 and 102' being heated and melted during the pressing process to flow to the area of the peripheral area of the edge of the active system 103' and then cooled and solidified to fill, so that the material of the sealing material layer 106 is the same as the material of the intermediate layer 102 and 102'. The sealing material layer 106 can also be a thickness compensation material layer made of hot melt adhesive pre-filled in the gap before the pressing process. As an example, the thickness compensation material layer can form a frame surrounding the outer periphery of the active system 103', and the material of the thickness compensation material layer is heated and melted during the pressing process to bond with the melted first intermediate layer 102 and second intermediate layer 102' on both sides, in which case the material of the sealing material layer 106 formed by the thickness compensation material layer can be the same as or different from the material of the first intermediate layer 102 and the second intermediate layer 102'.

[0103] In addition, the inventors surprisingly proved that when the materials of the first intermediate layer 102 and the second intermediate layer 102' are set to be different, it helps to further alleviate or even control the mura phenomenon of the laminated product. In particular, the first intermediate layer 102 and the second intermediate layer 102' are made of materials with different hardness. After experiments and theoretical analysis, the inventors believe that when one of the first intermediate layer 102 and the second intermediate layer 102' is made of a material with relatively harder hardness, and the other is made of a material with relatively softer hardness, the intermediate layer made of the material with relatively harder hardness can form a certain supporting effect, thereby preventing the thickness distribution of the light modulation layer in the active system from being uneven during the pressing and bonding process, and further alleviating the mura phenomenon of the finally obtained laminated product.

[0104] As a special case, the materials of the first intermediate layer 102 and the second intermediate layer 102' can be any two different materials selected from PVB, POE (Polyolefin Elastomer), EVA and the like. Among them, the hardness of POE and EVA materials is greater than that of PVB material. Therefore, in one example, the material of one of the first intermediate layer 102 and the second intermediate layer 102' is selected as PVB, and the material of the other can be selected as POE or EVA.

[0105] In a preferred embodiment, one of the first intermediate layer 102 and the second intermediate layer 102' can be made of a thermoplastic material, and the other can be made of a thermosetting material. Among them, the hardness of the thermosetting material can be greater than that of the thermosetting material. Such design can not only effectively alleviate the mura phenomenon caused during the pressing and bonding process, but also realize the later mura phenomenon improvement by means of the intermediate layer made of thermoplastic material.

[0106] Another embodiment of the present application provides a method for manufacturing a laminated product, as shown in FIG. 6, the method for manufacturing a laminated product in the embodiment comprises:

[0107] Step S601: providing a first and a second substrate, and an active system, the active system comprising a third and a fourth substrate stacked and arranged, and a light modulation layer between the third and the fourth substrate, the light modulation layer having a certain flowability, a first intermediate layer between the first substrate and the active system, and a second intermediate layer between the second substrate and the active system.

[0108] FIG. 4 shows a schematic diagram of the layer structure of the laminated product before being pressed and bonded in one example. As shown in FIG. 4, the first intermediate layer 102 is arranged between the first substrate 101 and the active system 103, and the second intermediate layer 102' is arranged between the second substrate 101' and the active system 103. The first intermediate layer 102 and the second intermediate layer 102' are made of hot melt adhesive, which melts into a state with a certain fluidity after exceeding a certain temperature, and can solidify into a solid state again after cooling, and bond the devices in contact therewith together.

[0109] The active system 103 includes the third substrate 1031 and the fourth substrate 1031' arranged in a stack, and the light modulation layer 1032 located between the third substrate 1031 and the fourth substrate 1031'. The light modulation layer 1032 has a certain fluidity. In order to seal the light modulation layer 1032, the active system 103 further includes the frame adhesive 1033 located in the peripheral region of the light modulation layer 1032, which is used to bond the third substrate 1031 and the fourth substrate 1031', and is a material that seals the light modulation layer 1032 together with the third substrate 1031 and the fourth substrate 1031'. It should be noted that the light modulation layer 1032 has a certain fluidity, and in FIG. 3 only the space occupied by the light modulation layer 1032 is shown, the horizontal dimension of which is limited by the area defined by the frame adhesive 1033.

[0110] The active system 103 has the same specific implementation details as the active system shown in FIG. 2A, and therefore the detailed description thereof will be omitted.

[0111] Step S602: Press and bond the first substrate, the first intermediate layer, the active system, the second intermediate layer, and the second substrate together, so that the thickness variation range of the light modulation layer in the active system is less than 1 / 4 of the wavelength of visible light.

[0112] The first intermediate layer 102 and the second intermediate layer 102' are made of hot melt adhesive, and can be heated and pressurized to the first substrate 101, the first intermediate layer 102, the active system 103, the second intermediate layer 102', and the second substrate 101', so that the first intermediate layer 102 and the second 102' are heated and melted, and have a certain fluidity, and under the action of pressure, they are fully flattened between the first substrate 101 and the active system 103, and between the active system 103 and the second substrate 101'. When cooled, the first intermediate layer 102 and the second intermediate layer 102' solidify, and the first substrate 101, the first intermediate layer 102, the active system 103, the second intermediate layer 102', and the second substrate 101' are pressed and bonded together to form an integral laminated product. The resulting laminated product is the same as the laminated product shown in FIG. 1.

[0113] It should be noted that the size of the active system 103 in the intermediate process of manufacturing the laminated article shown in FIG. 4 and the result of manufacturing the laminated article shown in FIG. 1 is substantially the same as the size of the first substrate 101 and the second substrate 101'.

[0114] In another alternative example, in order to seal the active system 103 more fully in the entire laminated article and avoid the active system 103 from being affected by the external environment and failing, the size of the active system can be designed to be smaller than the size of the first substrate 101 and the second substrate 101', for example, using the laminated article shown in FIG. 3. FIG. 5A shows a schematic diagram of the structure of each layer before pressing and bonding in the laminated article, and FIG. 5B shows a schematic diagram of the cross section of the structure of each layer in FIG. 5A. In this example, the size of the active system 103' is smaller than the size of the first substrate 101 and the second substrate 101'. The internal structure of the active system 103' can be exactly the same as the active system 103 in FIG. 4, which will not be described here.

[0115] In this case, although the area A01 around the active system 103' is a void area during the execution of step S1301, during the execution of step S1302, the first intermediate layer 102 and the second intermediate layer 102' are melted and have fluidity, and part of them will flow to the void area A01 under the action of pressure and gravity, so that the area can also be filled with the material of the melted first intermediate layer and / or second intermediate layer, and the area A01 can still remain sealed after cooling. In addition, it should be noted that the thickness of the active system 103' is exaggerated in FIG. 5A and FIG. 5B, and in practice the thickness of the active system 103' is thinner, so the thickness of the void area A01 is also thinner, and it is possible to fill the area with the material of the melted first intermediate layer and / or second intermediate layer. In addition, in alternative embodiments, a layer of thickness compensation material made of hot melt adhesive can be pre-filled in the void area A01 to compensate for the thickness difference in the area, and the layer of thickness compensation material is melted and bonded to the melted first intermediate layer 102 and second intermediate layer 102' on both sides during the execution of step S1302.

[0116] The active system 103' includes a third substrate 1031 and a fourth substrate 1031' stacked together, and a light modulation layer 1032 between the third substrate 1031 and the fourth substrate 1031'. The light modulation layer 1032 has a certain fluidity. In order to seal the light modulation layer 1032, the active system 103 further includes a frame glue 1033 around the periphery of the light modulation layer 1032.

[0117] The inventors have found through experiments that the laminated product in the example scenario shown in FIGS. 5A and 5B sometimes has a mura phenomenon because the local thickness difference causes a difference in visual effect. Therefore, in the embodiments of the present application, the thickness variation range of the light modulation layer of the active system in the final pressing laminated product is less than 1 / 2 of the wavelength of visible light, which can effectively avoid the mura phenomenon. The 1 / 2 of the wavelength of visible light can be within the closed interval of 200nm-350nm.

[0118] More preferably, the thickness variation range of the light modulation layer can be less than 1 / 4 of the wavelength of visible light, and the 1 / 4 of the wavelength of visible light can be within the closed interval of 100nm-175nm.

[0119] Through experimental verification and theoretical analysis, the mura phenomenon comes from the interference of light and the significant difference in light transmittance caused by the absorption of dichroic dye in different thickness areas. Controlling the thickness variation range of the light modulation layer to be less than 1 / 2 of the wavelength of visible light, especially less than 1 / 4 of the wavelength of visible light, can effectively alleviate the variation amplitude of light transmittance in different areas and the degree of perception by the human eye.

[0120] In addition, better control of thickness uniformity can be based on a pressing process controlled in the space-time dimension, in which the first substrate, the active system, and the second substrate are pressed and combined together through an intermediate layer. Specifically, the pressing process controlled in the space-time dimension includes a pressing process controlled in correspondence with time and / or area. The "area" can refer to the entire area or multiple sub-areas of the active system. The pressing process control includes control of process parameters, for example, the pressing process controlled in correspondence with time and / or area can include control processes of the vacuum degree of the pressing environment and / or the heating and melting temperature in correspondence with time / area.

[0121] The preferred embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, and these simple modifications all belong to the protection scope of the present application.

[0122] In addition, various different embodiments of the present application can also be combined arbitrarily, as long as they do not deviate from the idea of the present application, and they should also be considered as disclosed content of the present application.

Claims

1. A laminate characterized by, The application relates to an active system, comprising: a first substrate and a second substrate arranged oppositely; an active system arranged between the first and second substrates, the active system comprising a third substrate and a fourth substrate arranged in a stack, and a light modulation layer arranged between the third and fourth substrates, the light modulation layer having a certain fluidity; a first intermediate layer arranged between the active system and the first substrate, and a second intermediate layer arranged between the active system and the second substrate, the first and second intermediate layers being made of hot melt adhesive; a thickness of the light modulation layer in the active system varies in a range less than 1 / 2 of a wavelength of visible light.

2. A laminate according to claim 1, wherein The light modulation layer has a variable optical conversion function which changes according to an electric field, thermal energy, pressure or magnetic field applied thereon.

3. A laminate according to claim 2, wherein The variable optical conversion function of the light modulation layer includes transmission, absorption, reflection, diffraction and / or scattering.

4. A laminate according to claim 1, wherein The light modulation layer comprises a dye-free liquid crystal layer, a liquid crystal layer with added dichroic dye or a suspended particle material layer.

5. A laminate according to claim 4, wherein the polymeric material is a polyolefin. The liquid crystal layer comprises nematic liquid crystal, cholesteric liquid crystal, smectic liquid crystal or columnar liquid crystal.

6. A laminate according to claim 5, wherein the adhesive is a pressure sensitive adhesive. The liquid crystal layer further comprises a polymer network for stabilizing the cholesteric liquid crystal.

7. A laminate according to claim 1 wherein, The active system as a whole has flexibility.

8. A laminate according to claim 7, wherein the adhesive is a pressure sensitive adhesive. At least one of the third and fourth substrates in the active system is a flexible substrate.

9. A laminate according to claim 8, wherein the adhesive is a pressure sensitive adhesive. The flexible substrate is made of PET, PC or ultra-thin glass.

10. A laminate according to claim 1, wherein The hot melt adhesive comprises thermoplastic material or thermosetting material.

11. A laminate according to claim 10, wherein the adhesive is a pressure sensitive adhesive. The thermoplastic material comprises polyvinyl butyral resin PVB or ionic interlayer SGP.

12. A laminate according to claim 10, wherein the adhesive is a pressure sensitive adhesive. The thermosetting material comprises ethylene-vinyl acetate copolymer EVA or polyolefin elastomer POE.

13. A laminate according to claim 1 wherein, The active system comprises an optical conversion function area and a non-optical conversion function area.

14. A laminate according to claim 13, wherein the adhesive is a pressure sensitive adhesive. The non-optical conversion function area is an area where a frame adhesive is arranged in the active system, the frame adhesive is used for bonding the third and fourth substrates and sealing the material of the light modulation layer together with the third and fourth substrates.

15. A laminate according to claim 1, wherein the adhesive is a pressure sensitive adhesive. The light modulation layer comprises a liquid crystal layer, the liquid crystal layer comprises a liquid crystal composition and dichroic dye, the liquid crystal composition comprises nematic liquid crystal composition, chiral compound and bimesogenic compound.

16. A laminate according to claim 15, wherein the adhesive is a pressure sensitive adhesive. The liquid crystal layer changes the arrangement state of liquid crystal molecules in the liquid crystal layer under an applied electric field, the arrangement state of the liquid crystal molecules has at least two stable states which remain basically stable after the electric field is removed, at least one of the stable states is a transmission state, the collimated transmission light flux of visible light incident on the liquid crystal layer in the transmission state is greater than the scattered light flux, at least one of the stable states is a shielding state, the collimated transmission light flux of visible light incident on the liquid crystal layer in the shielding state is less than the collimated transmission light flux in the transmission state.

17. A laminate article according to claim 15, wherein, The bimesogenic compound is a liquid crystal compound containing two mesogenic groups in the molecule, and has a structure of R1-MG1-X-MG2-R2, wherein R1 and R2 each independently represent -H, -F, -Cl, or an alkyl group having 1-25 carbon atoms, wherein one or more H atoms in the alkyl group having 1-25 carbon atoms can each independently be substituted with a halogen, and one or more non-adjacent -CH2- in the alkyl group having 1-25 carbon atoms can each independently be replaced with -O-, -CH=CH-, -CH=CF- or -CF=CF-; MG1 and MG2 each independently represent a mesogenic group; and X is a linear or branched alkylene group having 3-40 carbon atoms, wherein one or more -CH2- in the linear or branched alkylene group having 3-40 carbon atoms can each independently be replaced with -O-, -CH(F)-, -CH(Cl)- or -CH=CH-, in a manner that does not contain two -O- adjacent to each other or two double bonds adjacent to each other; and the bimesogenic compound accounts for 10wt%-50wt% of the liquid crystal composition.

18. A laminate article according to claim 16, wherein, The liquid crystal layer can be in at least three states: high transparency, low haze state, low coloration, low haze state and high coloration, high haze state, for visible light and near-infrared light incident thereon.

19. A laminate according to claim 1, wherein, The materials of the first intermediate layer and the second intermediate layer are different.

20. A laminate article according to claim 19, wherein, The first intermediate layer and the second intermediate layer are made of materials with different hardness.

21. A method of making a laminate characterized by, Comprising: A first substrate, a second substrate, and an active system are provided, the active system comprising a third and a fourth substrate arranged in a stack, and a light modulation layer between the third and the fourth substrate, the light modulation layer having a certain fluidity, a first intermediate layer between the first substrate and the active system, and a second intermediate layer between the second substrate and the active system, the first intermediate layer and the second intermediate layer being made of hot melt glue, The first substrate, the first intermediate layer, the active system, the second intermediate layer and the second substrate are pressed together, and the thickness of the light modulation layer in the active system is changed in a range less than 1 / 2 of the wavelength of visible light.

22. The method of making a laminate article of claim 21, wherein, The pressing together of the first substrate, the first intermediate layer, the active system, the second intermediate layer and the second substrate comprises a pressing process controlled in space-time dimensions, by pressing together the first substrate, the first intermediate layer, the active system, the second intermediate layer and the second substrate.

23. The method of making a laminate article of claim 22, wherein, The pressing process controlled in space-time dimensions comprises a pressing process controlled in correspondence with time and / or area.

24. The method of making a laminate article of claim 23, wherein, The pressing process controlled in correspondence with time and / or area comprises: Control of the vacuum degree of the pressing environment and / or the heating melting temperature in correspondence with time / area.

25. The method of making a laminate article of claim 21, wherein, The active system comprises an optical transformation functional region and a non-optical transformation functional region.

26. The method of making a laminate article of claim 25, wherein, The non-optical transformation functional region is a region in the active system where a frame glue is arranged, the frame glue being used to bond the third and the fourth substrates, and sealing the material of the light modulation layer together with the third and the fourth substrates.

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