Laminating film, laminating method and folded optical path lens

Abstract

The invention provides a laminating film, a laminating method and a folded optical path lens. The laminating film comprises a base material, a viscosity-reducing adhesive layer and a release protective film which are sequentially laminated, the light transmittance of a composite layer of the base material and the viscosity-reducing adhesive layer is greater than or equal to 90%, the laminating film is laminated with a target optical structure at a laminating temperature, and the composite layer is softened at the laminating temperature. Therefore, the laminating film disclosed by the invention does not generate light path interference on the optical functional layer laminated with the laminating film, and further does not influence the optical performance of the optical functional layer; compared with the prior art, the composite film has the advantages that the composite film is good in adhesion property, stable in thermal and mechanical performance and free of qualitative change, so that the composite layer can be well matched with the appearance of an optical assembly (such as a lens) and well attached to the optical assembly at the attaching temperature, and meanwhile the base material and the viscosity-reducing adhesive layer do not generate undesirable phenomena such as corrosion to the optical functional layer attached to the base material and the viscosity-reducing adhesive layer.

Description

Technical Field

[0001] The present invention relates to the field of material technology, and in particular to a laminating film, a laminating method and a folded optical path lens. Background Art

[0002] Optical functional film is an indispensable and important component in various optical devices. Usually, optical functional film realizes specific functions by bonding on the surface of lens. Lenses can be divided into two categories: flat and curved. Therefore, the bonding of optical functional film also includes two processes: flat bonding and curved bonding. Compared with flat bonding, the film material curved bonding process is more complicated, but the curved surface bonding can increase the optical design space, especially in the field of VR. The curved surface bonding reflective polarizing film (RP film) can make the reflective surface of RP present a curved surface. The combination of two reflective curved surfaces can achieve better optical performance of Pancake (folded optical path) lens group. In the process of curved bonding, in order to protect the functional film from scratches and wear, a layer of bonding film (carrier film, CF) needs to be bonded to the outside of the optical functional film. The higher temperature softens the film. With the assistance of external fixtures, the gripping force generated by the bonding film adhesive layer is used to plasticize the optical functional film surface, and then the bonding with the lens is completed. After bonding, the bonding film is removed to obtain the lens with the optical functional film bent.

[0003] During the bonding process of optical functional films and lens lenses, due to the particularity of the optical path, if the optical properties of the optical functional films (such as reflection, polarization, etc.) are to be fully utilized, the optical axis angles between the multiple layers of optical functional films need to be aligned before use. For example, in the pancake lens solution, the slow axis of the wavelength phase delay film (QWP) and the transmission axis of the reflective polarizing film (RP) need to be precisely at a 45° angle, and the transmission axes of the RP and LP need to coincide precisely, otherwise there will be display problems such as stray light and ghosting.

[0004] There are usually two methods for bonding optical functional films to lens lenses:

[0005] The first method: mark the surface of the optical functional film material in advance, including but not limited to points, straight lines, right angles, etc., and then use CCD (charge coupled device) to capture the marked points to obtain the optical axis angle information of the optical functional film material. Then the rotating machine rotates according to the current angle information to ensure that the optical axis angle between the optical functional film materials reaches the preset value, and then the bonding action is performed, which is referred to as visual recognition alignment bonding (this bonding process can be called CCD alignment bonding). CCD alignment bonding is an indirect bonding method. For an optical functional composite film material, the optical axis of each layer of the optical functional composite film material needs to be detected in advance, which is time-consuming and labor-intensive. In addition, the optical axis uniformity of the optical functional film material is required to be high. Otherwise, the local optical axis detection of the optical functional film material cannot guarantee the accuracy of the final alignment angle, and finally there will be display problems such as stray light and ghosting.

[0006] The second method: using a beam of polarized light to pass through the optical functional film material that needs to be aligned and enter the receiver, the angle relationship between various film materials can be obtained by detecting some characteristics of the polarized light (intensity, phase and other information), and then the rotation correction is performed using a rotating machine, and then the bonding action is performed, which is referred to as polarized optical alignment (this bonding process can be called AA alignment bonding). AA alignment bonding is a direct bonding method that can ensure more accurate alignment between optical functional film materials, introduce fewer process procedures, and have relatively low requirements for the uniformity of the optical axis of the optical functional film material.

[0007] In the above two bonding methods, AA alignment bonding has irreplaceable advantages, but because the bonding film is in the polarized light path, the bonding film cannot interfere with the polarized light path, and at the same time, it can be curved with the optical functional film material to complete the bonding with the lens. However, it is difficult for the current bonding film to meet the above multiple requirements at the same time. Summary of the invention

[0008] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, one purpose of the present invention is to provide a bonding film that can meet the performance requirements of the bonding film in optical alignment bonding in terms of thermal and mechanical properties, and will not interfere with the optical path of the target optical structure (such as the optical functional layer).

[0009] In one aspect of the present invention, the present invention provides a bonding film. According to an embodiment of the present invention, the bonding film includes a substrate, a viscosity-reducing adhesive layer and a release protective film which are stacked in sequence, wherein the light transmittance of the composite layer of the substrate and the viscosity-reducing adhesive layer is greater than or equal to 90%, and the bonding film is bonded to the target optical structure at the bonding temperature, and the composite layer softens at the bonding temperature. Therefore, the above-mentioned bonding film of the present invention will not interfere with the optical path of the target optical structure (such as an optical functional layer) bonded thereto, and will not affect the optical properties of the optical functional layer; and the thermal and mechanical properties are stable and will not undergo qualitative changes, so at the bonding temperature, the composite layer can well match the morphology of the optical component (such as a lens) and bond well therewith, and at the same time, the substrate and the viscosity-reducing adhesive layer will not cause corrosion and other adverse phenomena to the target optical structure (such as an optical functional layer) bonded thereto.

[0010] According to an embodiment of the present invention, the substrate satisfies at least one of the following conditions: the thickness of the substrate is 30 to 150 microns, and the thickness deviation at different positions is less than or equal to 5%; the surface roughness Ra of the substrate is less than or equal to 0.5 microns; the surface tension of the substrate is greater than or equal to 50 mN / m.

[0011] According to an embodiment of the present invention, at the bonding temperature, the elongation at break of the substrate is greater than or equal to 10%.

[0012] According to an embodiment of the present invention, the substrate further satisfies at least one of the following conditions: the softening temperature of the substrate is greater than or equal to a predetermined temperature, the predetermined temperature being the bonding temperature -30°C; the substrate is treated at the bonding temperature for a predetermined time, and the morphology and color of the substrate remain unchanged.

[0013] According to an embodiment of the present invention, the substrate further satisfies at least one of the following conditions: the light transmittance of the substrate is greater than or equal to 90%; the haze of the substrate is less than or equal to 1%; and the in-plane phase delay R0 of the substrate is less than or equal to 10 nanometers.

[0014] According to an embodiment of the present invention, the substrate includes at least one of polymethyl methacrylate, polycarbonate, triacetyl cellulose, cycloolefin polymer, cycloolefin copolymer, polyester, polypropylene, polyethylene, polyolefin, polyimide, thermoplastic polyurethane and polyvinyl chloride.

[0015] According to an embodiment of the present invention, the viscosity-reducing adhesive layer satisfies at least one of the following conditions: the thickness of the viscosity-reducing adhesive layer is 0.1 to 20 microns, and the thickness deviation at different positions is less than or equal to 5%; the viscosity-reducing adhesive layer includes at least one of acrylic glue, epoxy glue, organic silicone and polyurethane glue; the coating method for forming the viscosity-reducing adhesive layer includes at least one of slit coating, micro-concave coating and scraper coating.

[0016] According to an embodiment of the present invention, the viscosity-reducing adhesive layer also satisfies at least one of the following conditions: the peeling force between the viscosity-reducing adhesive layer and the adhesive film layer before viscosity reduction is greater than or equal to 1000 gf / cm 2 The peeling force between the adhesive layer and the adhesive film layer after the viscosity reduction is less than or equal to 100gf / cm 2 .

[0017] According to an embodiment of the present invention, the anti-viscosity adhesive layer is a UV anti-viscosity adhesive layer, and the UV anti-viscosity adhesive layer satisfies at least one of the following conditions: the wavelength of UV light is 365 nanometers to 410 nanometers; the light intensity density received by the adhesive surface of the UV anti-viscosity adhesive layer is greater than or equal to 2000 mJ / cm 2 .

[0018] According to an embodiment of the present invention, the UV anti-viscosity adhesive layer also satisfies at least one of the following conditions: the UV anti-viscosity adhesive layer has a tolerance time of not less than 3 minutes at the bonding temperature; when the thickness of the UV anti-viscosity adhesive layer is 100 microns, the transmittance of the UV anti-viscosity adhesive layer is greater than or equal to 90%, and the haze is less than or equal to 1%.

[0019] According to an embodiment of the present invention, the release protective film satisfies at least one of the following conditions: the thickness of the release protective film is 5 to 100 microns; the surface roughness Ra of the release protective film is less than or equal to 0.5 microns; the residual bonding rate of the release protective film is greater than or equal to 90%; the peeling force between the release protective film and the adhesive layer is less than or equal to 200gf / cm 2 .

[0020] In another aspect of the present invention, the present invention provides a bonding method. According to an embodiment of the present invention, the bonding method includes: providing a first bonding film, the first bonding film is the bonding film described above, and removing the release protective film of the first bonding film; providing a first optical functional layer, the first optical functional layer includes a first functional layer body and a first adhesive layer stacked; pasting the surface of the first bonding film's viscosity-reducing adhesive layer to the surface of the first functional layer body away from the first adhesive layer to obtain a first composite layer body; providing a lens and a bonding groove, the bonding groove includes an upper bonding groove and a lower bonding groove, the lens and the bonding surface of the upper bonding groove and the bonding surface of the lower bonding groove are matched respectively, and the lens is placed on the bonding surface of the lower bonding groove; the first composite layer body is placed on the side of the lens away from the lower bonding groove, and the first adhesive layer is arranged close to the lens; the temperature is heated to the bonding temperature, so that the first composite layer body softens, and the upper bonding groove is bonded to the first composite layer body and pressed; remove the bonding groove. Therefore, the above-mentioned bonding method of the present invention has high bonding accuracy, simple process, easy implementation and industrial production, and the bonding film will not interfere with the optical path of the optical functional layer bonded to it, and thus will not affect the optical properties of the optical functional layer; and the thermal and mechanical properties are stable and will not undergo qualitative changes. Therefore, at the bonding temperature, the composite layer can well match the morphology of the optical component (such as a lens) and bond well with it, and at the same time, the substrate and the viscosity-reducing adhesive layer will not cause corrosion and other adverse phenomena to the optical functional layer bonded to it.

[0021] According to an embodiment of the present invention, the bonding method also includes: providing a second bonding film, the second bonding film is the bonding film described above, and removing the release protective film of the second bonding film; providing a second optical functional layer, the second optical functional layer includes a second functional layer body and a second adhesive layer stacked in layers; bonding the surface of the viscosity-reducing adhesive layer of the second bonding film to the surface of the second functional layer body away from the second adhesive layer to obtain a second composite layer body; placing the other surface of the lens on the bonding surface of the lower bonding groove, and the substrate of the first bonding film is in contact with the bonding surface of the lower bonding groove; placing the second composite layer body on the side of the lens away from the lower bonding groove, and the second adhesive layer is arranged close to the lens; heating the temperature to the bonding temperature to soften the second composite layer body, and bonding the upper bonding groove to the second composite layer body and performing a pressing process; removing the bonding groove.

[0022] According to an embodiment of the present invention, the bonding method further includes: irradiating the substrate surface of the first bonding film and the substrate surface of the second bonding film with UV light respectively, so that the peeling force of the viscosity-reducing adhesive layer of the first bonding film and the viscosity-reducing adhesive layer of the second bonding film is reduced; peeling off the viscosity-reducing adhesive layer of the first bonding film and the substrate, and peeling off the viscosity-reducing adhesive layer of the second bonding film and the substrate.

[0023] According to an embodiment of the present invention, the first functional layer body includes at least one of a wavelength phase retardation film, a reflective polarization film and a linear polarization film, and the second functional layer body includes at least one of the wavelength phase retardation film, the reflective polarization film and the linear polarization film.

[0024] According to an embodiment of the present invention, the lamination temperature is 100-130°C.

[0025] In another aspect of the present invention, the present invention provides a folded light path lens. According to an embodiment of the present invention, the folded light path lens comprises a lens and an optical function layer, the optical function layer is bonded to the surface of the lens, and the bonding method is implemented by the bonding method described above. As a result, the folded light path lens has good optical performance and is not prone to realistic problems such as stray light and ghosting. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0027] Figure 1 is a schematic structural diagram of a laminating film in one embodiment of the present invention;

[0028] Figure 2 is a structural flow chart of a bonding method in another embodiment of the present invention;

[0029] Figure 3 is a schematic structural diagram of the bonding of a lens and an optical functional layer in another embodiment of the present invention;

[0030] Figure 4 A structural flow chart of a bonding method in another embodiment of the present invention;

[0031] Figure 5 is a schematic structural diagram of the bonding of a lens and an optical functional layer in another embodiment of the present invention;

[0032] Figure 6 is a flow chart of removing the laminating film in another embodiment of the present invention;

[0033] Figure 7 It is a schematic structural diagram of a folded optical path lens in yet another embodiment of the present invention. DETAILED DESCRIPTION

[0034] The scheme of the present invention will be explained below in conjunction with embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are followed.

[0035] The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0036] In one aspect of the present invention, the present invention provides a laminating film for optical alignment lamination. Figure 1 The laminating film 100 comprises a substrate 110, a viscosity-reducing adhesive layer 120 and a release protective film 130 which are stacked in sequence, wherein the transmittance of the composite layer 12 of the substrate 110 and the viscosity-reducing adhesive layer 120 is greater than or equal to 90%, and the laminating film is laminated with the target optical structure at the laminating temperature, and the composite layer softens at the laminating temperature. Therefore, the laminating film 100 of the present invention will not interfere with the optical path of the target optical structure (such as the optical functional layer) laminated thereto, and will not affect the optical properties of the optical functional layer; and the thermal and mechanical properties are stable and will not undergo qualitative changes, so at the laminating temperature, the composite layer can well match the morphology of the optical component (such as the lens) and laminate well therewith, and at the same time, the substrate and the viscosity-reducing adhesive layer will not cause corrosion and other adverse phenomena to the target optical structure (such as the optical functional layer) laminated thereto, and the composite layer 12 softens at the laminating temperature while its morphology and color do not change, effectively realizing the direct alignment of the optical component and the optical functional layer, that is, realizing AA alignment.

[0037] It should be noted that the above-mentioned bonding temperature refers to the temperature of the composite layer body after the bonding film and the optical functional layer are bonded to the optical component (such as a lens). In addition, the composite layer 12 has no change in shape and color at the bonding temperature, wherein no change in shape does not mean that the composite layer 12 softens, but means that no undesirable phenomena such as wrinkles and curling will occur; no change in color means that the substrate has no defects such as whitening, blackening, discoloration, etc. within the range visible to the naked eye.

[0038] According to some embodiments of the present invention, in order to obtain a laminating film with better performance, the basic physical properties of the substrate 110 include the following requirements: the thickness of the substrate is 30 to 150 microns (for example, 30 microns, 40 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns, 110 microns, 120 microns, 130 microns, 140 microns, 150 microns, etc.), and the thickness deviation at different positions is less than or equal to 5%. In this way, the flatness of the substrate is high, which can improve the adhesion between the substrate and the viscosity-reducing adhesive layer, while ensuring the uniformity of the overall thickness of the laminating film; the surface roughness Ra of the substrate is less than or equal to 0.5 microns, for example, Ra is 0.5 microns, 0.45 microns, 0.4 microns , 0.35 micron, 0.3 micron, 0.25 micron, 0.2 micron or 0.1 micron, so that the flatness of the substrate is relatively high, thereby improving the adhesion between the substrate and the viscosity-reducing adhesive layer; the surface tension of the substrate is greater than or equal to 50mN / m, for example, the surface tension is 50mN / m, 55mN / m, 60mN / m, 65mN / m, 70mN / m, 75mN / m, 80mN / m, 85mN / m, 90mN / m, etc. The above surface tension requirements can greatly improve the surface flatness and smoothness of the substrate, thereby improving the adhesion between the viscosity-reducing adhesive layer and the substrate, improving the overall stability of the bonding film, and improving the bonding and bonding between the bonding film and the target optical structure (such as the optical functional layer).

[0039] According to some embodiments of the present invention, at the bonding temperature, the elongation at break of the substrate is greater than or equal to 10%, such as 10%, 12%, 14%, 15%, 17%, 19%, 20%, 22%, 25%, 27%, 29%, 30%, etc. As a result, the substrate has a suitable deformation ability, which improves the overall deformation ability of the bonding film. When the bonding film is bonded to a curved lens, the bonding film has a high thermoplasticity to match the curved surface, thereby achieving good bonding between the bonding film and the curved lens.

[0040] According to some embodiments of the present invention, the softening temperature of the substrate is greater than or equal to a predetermined temperature, and the predetermined temperature is the laminating temperature - 30°C. For example, if the laminating temperature is 100°C, then the predetermined temperature is 70°C, that is, the softening temperature needs to be greater than or equal to 70°C. During the laminating process, if the softening temperature of the substrate is too low, it will cause the laminating film to shrink and deform seriously during use, and even cause problems such as melting and rupture. The above softening temperature requirements of the present invention can effectively avoid the laminating film from shrinking and deforming seriously. Further, in some embodiments, the laminating temperature can be 100-130°C, such as 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, etc. At the above temperature, the composite layer 12 can be softened so as to match the curved lens for bonding, and the above temperature will not have any adverse effects on the various film layers in the composite layer 12, nor will it cause obvious changes in shape and color, that is, no wrinkles, curling, whitening, blackening, discoloration and other defects, nor will it have any adverse effects on the lens.

[0041] In some embodiments of the present invention, the substrate is baked at the bonding temperature for a predetermined time, and the morphology and color of the substrate remain unchanged, wherein the unchanged morphology does not mean that the bonding film softens, but means that no undesirable phenomena such as wrinkles and curling will occur; the unchanged color means that within the range visible to the naked eye, the substrate has no defects such as whitening, blackening, and discoloration. In this way, it can be ensured that the substrate will not have undesirable phenomena such as wrinkles and curling during the bonding process, and at the same time, it can be prevented from undergoing qualitative changes, thereby ensuring good bonding between the bonding film and optical components such as lenses. Furthermore, in some embodiments, the predetermined time is 3 minutes, that is, the substrate is baked at the bonding temperature for 3 minutes, and the morphology and color of the substrate do not change. Within the above time range, the bonding film and the optical component can be effectively bonded well.

[0042] According to some embodiments of the present invention, the transmittance of the substrate is greater than or equal to 90%. In this way, the substrate and even the bonding film will not have a significant absorption of the required working light (such as polarized light), and will basically not have an adverse effect on the optical path of the light (such as polarized light) of the optical functional layer, thereby ensuring good light propagation of the optical functional layer and optical components.

[0043] In some embodiments of the present invention, the haze of the substrate is less than or equal to 1%, so that the substrate does not emit significant light, thereby ensuring good light (such as polarized light) propagation.

[0044] In some embodiments of the present invention, the in-plane phase delay R0 of the substrate is less than or equal to 10 nanometers. In this way, the lower delay can ensure that the bonding film can be bonded to the optical functional layer at any angle without adversely affecting the alignment effect of subsequent polarized light and other light. In some specific embodiments, the in-plane phase delay of the substrate is less than or equal to 3 nanometers. In this way, the substrate has a smaller impact on light propagation, and can even control the optical alignment angle deviation within 0.5%. Among them, when a beam of light passes through a film material with birefringence, it is divided into o light and e light, and the in-plane phase delay R0 = |no-ne|*d, no and ne are the refractive indices of o light and e light in the film material, and d is the thickness of the film material.

[0045] According to some embodiments of the present invention, the substrate includes at least one of polymethyl methacrylate (PMMA), polycarbonate (PC), triacetyl cellulose (TCA), cycloolefin polymer (COP), cycloolefin copolymer (COC), polyester (such as PEN, PET, OKP, etc.), polypropylene (PP), polyethylene (PE), polyolefin (PO), polyimide (PI), thermoplastic polyurethane (TPU) and polyvinyl chloride (PVC). The substrate formed by the above materials has the required good physical properties, thermal, mechanical and optical properties, meets the various requirements of the optical component and the optical functional layer for the bonding film, and helps to effectively achieve the AA alignment bonding of the optical component and the optical functional layer.

[0046] According to some embodiments of the present invention, the thickness of the anti-viscosity adhesive layer is 0.1 to 20 microns, and the thickness deviation at different positions is less than or equal to 5%. In this way, the anti-viscosity adhesive layer has a high flatness, which can improve the adhesion between the substrate and the anti-viscosity adhesive layer, while ensuring the uniformity of the overall thickness of the bonding film, and improving the bonding effect between the bonding film and the optical functional layer and the optical component.

[0047] According to some embodiments of the present invention, the viscosity-reducing adhesive layer includes at least one of acrylic adhesive, epoxy adhesive, organic silicone adhesive and polyurethane adhesive. The adhesive layer of the above system has good stability and will not cause adverse phenomena such as corrosion to the layer structure in contact with it. In some specific embodiments, the viscosity-reducing adhesive layer is acrylic adhesive, so that it has better stability and is more friendly to the layer structure in contact with it.

[0048] According to some embodiments of the present invention, the coating method for forming the viscosity-reducing adhesive layer includes at least one of slit coating, micro-dimpled coating, and blade coating. In the present invention, a variety of coating methods can be selected, and there is no special requirement for the formation method, thereby reducing the formation process conditions of the laminating film and reducing the cost.

[0049] According to some embodiments of the present invention, the peeling force between the adhesive layer and the adhesive film layer before the adhesive layer is reduced is greater than or equal to 1000 gf / cm2 , for example, the peel force is 1000gf / cm 2 、1050gf / cm 2 、1100gf / cm 2 、1150gf / cm 2 , 1200gf / cm 2 、1250gf / cm 2 , 1300gf / cm 2 、1350gf / cm 2 , 1400gf / cm 2 、1450gf / cm 2 , 1500gf / cm 2 In this way, the laminating film and the adhered film layer (such as the optical functional layer) have good adhesion, and it is not easy to cause problems such as misalignment in the subsequent process. In some specific embodiments, the peeling force between the adhesive layer and the adhered film layer before the adhesive is released is greater than or equal to 1500gf / cm 2 , for example, the peel force is 1500gf / cm 2 、1550gf / cm 2 , 1600gf / cm 2 、1650gf / cm 2 、1700gf / cm 2 、1750gf / cm 2 , 1800gf / cm 2 、1850gf / cm 2 、1900gf / cm 2 、1950gf / cm 2 , 2000gf / cm 2 wait.

[0050] According to some embodiments of the present invention, the peeling force between the adhesive layer and the adhered film layer (such as the optical functional layer) after the adhesive layer is debonded is less than or equal to 100 gf / cm 2 , for example 100gf / cm 2 、95gf / cm 2 、90gf / cm 2 、85gf / cm 2 、80gf / cm 2 , 75gf / cm 2 、70gf / cm 2 、65gf / cm 2 、60gf / cm 2 , 55gf / cm 2 , 50gf / cm 2In this way, after the viscosity-reducing adhesive layer is subjected to the viscosity-reducing treatment, the adhesive force between the viscosity-reducing adhesive layer and the adhered film layer is greatly weakened, and the two can be easily peeled off without causing any adverse effects on the adhered film layer. In some specific embodiments, the peeling force between the viscosity-reducing adhesive layer and the adhered film layer (such as the optical functional layer) after the viscosity-reducing treatment is less than or equal to 50gf / cm 2 , for example 50gf / cm 2 , 45gf / cm 2 , 40gf / cm 2 、35gf / cm 2 、30gf / cm 2 , 25gf / cm 2 , 20gf / cm 2 , 15gf / cm 2 , 10gf / cm 2 wait.

[0051] According to some embodiments of the present invention, the viscosity-reducing adhesive layer is a UV viscosity-reducing adhesive layer, and the wavelength of UV light is 365 nanometers to 410 nanometers. For example, a mercury lamp, a metal halide lamp, an LED lamp, etc. can be selected. In this way, the present invention has a wide range of selectivity for the wavelength of UV light, thereby reducing the difficulty of viscosity-reducing treatment. In some embodiments, those skilled in the art can also select a light source with a wavelength less than 365 nanometers or a wavelength greater than 410 nanometers, as long as the viscosity can be effectively reduced and no adverse effects are caused on the adhesive film layer and the optical components.

[0052] According to some embodiments of the present invention, the light intensity density received by the adhesive surface of the UV adhesive layer is greater than or equal to 2000mJ / cm 2 In this way, the viscosity reduction effect can be achieved quickly and effectively, and the entire surface of the UV viscosity reduction adhesive layer can be subjected to viscosity reduction treatment, which will not lead to poor local viscosity reduction effect and avoid the local adhesive film layer from being torn during the peeling process.

[0053] According to some embodiments of the present invention, the UV anti-viscosity adhesive layer has a tolerance time of not less than 3 minutes at the bonding temperature. In this way, the UV anti-viscosity adhesive layer has good heat resistance and will not undergo other deformations (such as wrinkles, curling, etc.) other than qualitative changes and softening at the bonding temperature, thereby ensuring its good adhesion and stability, and will not affect the anti-viscosity effect after UV light exposure. It should be noted that the tolerance time refers to the time when the viscosity, anti-viscosity and other properties of the UV anti-viscosity adhesive layer are not affected by the temperature at the bonding temperature, or in other words, within the range of the tolerance time, the viscosity, anti-viscosity and other properties of the UV anti-viscosity adhesive layer do not change before and after the bonding temperature.

[0054] According to some embodiments of the present invention, when the thickness of the UV anti-viscosity adhesive layer is 100 microns, the light transmittance of the UV anti-viscosity adhesive layer is greater than or equal to 90%, and the haze is less than or equal to 1%. Therefore, the UV anti-viscosity adhesive layer has good light transmittance and does not significantly absorb the light that needs to be transmitted.

[0055] According to some embodiments of the present invention, the thickness of the release protective film is 5 to 100 microns, so that the viscosity-reducing adhesive layer can be well protected without making the overall thickness of the bonding film too thick.

[0056] According to some embodiments of the present invention, the surface roughness Ra of the release protective film is less than or equal to 0.5 microns. In this way, the surface of the release protective film is smooth, and will not adversely affect the viscosity of the viscosity-reducing adhesive layer when it is torn off, and the release protective film is easy to tear off.

[0057] According to some embodiments of the present invention, the residual adhesion rate of the release protective film is greater than or equal to 90%, so that the quality of the release protective film is good. The release protective film can use a silicon-containing or non-silicon release agent. The test method for the residual adhesion rate can adopt the test method of the national standard GB / T25256-2010.

[0058] According to some embodiments of the present invention, the peeling force between the release protective film and the viscosity-reducing adhesive layer is less than or equal to 200 gf / cm 2 In this way, the release protective film can be easily torn off without damaging the performance of the adhesive layer. In some specific embodiments, the peeling force between the release protective film and the adhesive layer is less than or equal to 100 gf / cm 2 .

[0059] In another aspect of the present invention, the present invention provides a bonding method. Figure 2 , the bonding method comprises:

[0060] S100: providing a first laminating film, the first laminating film being the laminating film 100 described above, and removing the release protective film 130 of the first laminating film (ie, the laminating film 100);

[0061] S200: providing a first optical functional layer 210, wherein the first optical functional layer 210 comprises a first functional layer body 211 and a first adhesive layer 212 which are stacked;

[0062] S300: pasting the surface of the viscosity-reducing adhesive layer 120 of the first laminating film to the surface of the first functional layer body 211 away from the first adhesive layer 212 to obtain a first composite layer body 01;

[0063] S400: providing a lens 300 and a bonding groove, wherein the bonding groove includes an upper bonding groove 410 and a lower bonding groove 420, wherein the topography of the lens 300 matches the bonding surface of the upper bonding groove 410 and the bonding surface of the lower bonding groove 420, respectively, and placing the lens 300 on the bonding surface of the lower bonding groove 410;

[0064] S500: placing the first composite layer 01 on a side of the lens 300 away from the lower bonding groove 420 , and the first adhesive layer 212 is disposed close to the lens 300 ;

[0065] In some embodiments, in this step, a clamp may be used to clamp the first laminating film to prevent the viscosity-reducing adhesive layer in the first laminating film and the substrate from being misaligned during the lamination process in the subsequent step. Furthermore, the clamp only clamps the first laminating film and does not clamp the first functional layer body, because the deformation of the first laminating film and the first functional layer body at the laminating temperature are different. If the clamp clamps the first laminating film and the first functional layer body at the same time, the laminating effect will be seriously affected due to the different deformation of the two.

[0066] S600: heating the temperature to the bonding temperature to soften the first composite layer body 01, and bonding the upper bonding groove 410 to the first composite layer body 01 and performing a pressing process;

[0067] S700: Remove the fitting groove.

[0068] According to some embodiments of the present invention, referring to Figure 3 After the bonding of the first composite layer body 01 is completed, the bonding method of the present invention further includes: cutting the first composite layer body 01 according to the size of the lens to obtain a first composite layer body 01 that matches the size of the lens.

[0069] According to some embodiments of the present invention, referring to Figure 4 The bonding method further includes bonding the optical functional layer and the bonding film on the other surface of the lens, which may specifically include:

[0070] T100: providing a second laminating film, which is the laminating film 100 described above, and removing the release protective film 130 of the second laminating film (i.e., the laminating film 100);

[0071] T200: providing a second optical functional layer 220, wherein the second optical functional layer 220 includes a second functional layer body 221 and a second adhesive layer 222 which are stacked;

[0072] T300: The surface of the viscosity-reducing adhesive layer 120 of the second laminating film is adhered to the surface of the second functional layer body 221 away from the second adhesive layer 222 to obtain a second composite layer body 02;

[0073] T400: Place the other surface of the lens 300 (the lower surface bonded to the first composite layer body 01) on the bonding surface of the lower bonding groove 420, and the substrate 110 of the first bonding film (the substrate 110 in the first composite layer body 01) is in contact with the bonding surface of the lower bonding groove 420;

[0074] T500: placing the second composite layer 02 on a side of the lens 300 away from the lower bonding groove 420 , and the second adhesive layer 222 is disposed close to the lens 300 ;

[0075] In some embodiments, in this step, a clamp may be used to clamp the second laminating film to prevent the viscosity-reducing adhesive layer in the second laminating film and the substrate from being misaligned during the subsequent lamination process. Furthermore, the clamp only clamps the second laminating film and does not clamp the second functional layer body, because the deformation of the second laminating film and the second functional layer body at the laminating temperature is different. If the clamp clamps the second laminating film and the second functional layer body at the same time, the laminating effect will be seriously affected due to the different deformation of the two.

[0076] T600: heating the temperature to the bonding temperature to soften the second composite layer body 02, and bonding the upper bonding groove 410 to the second composite layer body 02 and performing a pressing process;

[0077] T700: Remove the fitting groove.

[0078] According to some embodiments of the present invention, referring to Figure 5 After the bonding of the second composite layer body 02 is completed, the bonding method of the present invention further includes: cutting the second composite layer body 02 according to the size of the lens to obtain a second composite layer body 02 that matches the size of the lens.

[0079] According to some embodiments of the present invention, during the bonding process of the first composite layer body 01 and the lens and the bonding process of the second composite layer body 02 and the lens, the bonding temperature can be 100-130°C, such as 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, etc. At the above temperature, the first composite layer body 01 and the second composite layer body 02 can be softened so as to match the curved lens for bonding, and the above temperature will not have any adverse effects on the various film layers in the first composite layer body 01 and the second composite layer body 02, nor will it have any adverse effects on the lens. Among them, the bonding temperature of the first composite layer body 01 and the lens and the bonding temperature of the second composite layer body 02 and the lens can be the same or different, as long as they are between 100-130°C.

[0080] In some embodiments, the specific types of the first adhesive layer and the second adhesive layer can be independently optical adhesive (OCA) or sub-sensitive adhesive (PSA), and the two adhesives have better light transmittance.

[0081] According to some embodiments of the present invention, referring to Figure 6 After the first composite layer 01 and the second composite layer 02 are laminated, the adhesive layer 120 and the substrate 110 in the laminating film need to be removed. The specific removal method includes the following steps:

[0082] E100: UV light is irradiated to the substrate 110 surface of the first laminating film and the substrate 110 surface of the second laminating film respectively, so that the peeling force of the viscosity-reducing adhesive layer 120 of the first laminating film and the viscosity-reducing adhesive layer 120 of the second laminating film is reduced, thereby reducing the adhesion between the viscosity-reducing adhesive layer and the optical functional layer.

[0083] There is no special requirement for the intensity of UV light irradiation, and those skilled in the art can flexibly adjust the intensity of UV light irradiation according to actual conditions such as the peeling force of the debonding adhesive layer 120 before debonding and the requirements for the peeling force after debonding.

[0084] E200: Peeling off the viscosity-reducing adhesive layer 120 and the substrate 110 of the first laminating film, and peeling off the viscosity-reducing adhesive layer 120 and the substrate 110 of the second laminating film, thereby obtaining a lens with an optical functional layer attached, namely, a folded light path lens.

[0085] According to some embodiments of the present invention, the first functional layer body includes at least one of a wavelength phase retardation film (QWP, such as a 1 / 4 wavelength phase retardation film, a 1 / 2 wavelength phase retardation film, etc.), a reflective polarization film (PR), and a linear polarization film (LR), and the second functional layer body includes at least one of a wavelength phase retardation film, a reflective polarization film, and a linear polarization film. Therefore, those skilled in the art can flexibly select a specific optical functional film layer in the optical functional layer according to the specific application scenario and function of the lens.

[0086] Among them, since the reflective polarizing film RP and the wavelength phase delay film QWP have their own optical axis directions respectively, in order to ensure the good working performance of the lens with an optical functional layer, that is, the folded light path lens, it is necessary to make the optical axes of QWP and RP present a specific angle (for example, 45 degrees, 135 degrees, etc.). Therefore, before the RP is bent, the polarized laser equipped on the machine needs to pass through the bonding film, reflective polarizing film RP, adhesive layer, lens, adhesive layer, wavelength phase delay film QWP in sequence (the order is also reverse), and finally received and analyzed by the receiver to obtain the real-time angle of RP and QWP, and finally the lens is automatically rotated by the robotic arm to achieve the specific angle satisfied by RP and QWP. In this process, the bonding film of the present invention has no effect on the optical path of the polarized light, and thus will not affect the optical performance of the optical functional layer, thereby ensuring the good performance of the folded light path lens.

[0087] According to the embodiments of the present invention, the above-mentioned bonding method of the present invention has high bonding accuracy, simple process, easy implementation and industrial production, and the bonding film will not interfere with the optical path of the optical functional layer bonded thereto, thereby not affecting the optical properties of the optical functional layer; and the thermal and mechanical properties are stable and will not undergo qualitative changes, so at the bonding temperature, the composite layer can well match the morphology of the lens and bond well therewith, and at the same time, the substrate and the viscosity-reducing adhesive layer will not cause corrosion and other adverse phenomena to the optical functional layer bonded thereto.

[0088] In another aspect of the present invention, the present invention provides a folded optical path lens. Figure 7 The folded light path lens includes a lens 300 and an optical function layer (including a first optical function layer 210 and a second optical function layer 220), and the optical function layer is bonded to the surface of the lens, and the bonding method is achieved by the bonding method described above. Therefore, the folded light path lens has good optical performance and is not prone to realistic problems such as stray light and ghosting.

[0089] According to an embodiment of the present invention, the folded light path lens of the present invention may further include structures or components necessary for a conventional folded light path lens in addition to the above-mentioned lens and optical functional layer. For example, in some embodiments, the folded light path lens of the present invention may further include a semi-transparent and semi-reflective film (BS) in addition to the above-mentioned lens and optical functional layer. The semi-transparent and semi-reflective film is arranged on the side of the optical functional layer away from the lens. For example, if the optical functional film layer includes a wavelength phase delay film (QWP) and a reflective polarizing film (PR), the semi-transparent and semi-reflective film BS may be arranged on the side of the wavelength phase delay film (QWP) away from the reflective polarizing film (PR).

[0090] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0091] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0092] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A laminating film, It is characterized in that The laminating film comprises a substrate, a viscosity-reducing adhesive layer and a release protective film which are stacked in sequence, wherein: The light transmittance of the composite layer of the substrate and the viscosity-reducing adhesive layer is greater than or equal to 90%, and the laminating film is laminated to the target optical structure at a laminating temperature, at which the composite layer softens.

2. The laminating film according to claim 1, It is characterized in that The substrate meets at least one of the following conditions: The thickness of the substrate is 30 to 150 microns, and the thickness deviation at different positions is less than or equal to 5%; The surface roughness Ra of the substrate is less than or equal to 0.5 micrometer; The surface tension of the substrate is greater than or equal to 50 mN / m.

3. The laminating film according to claim 2, It is characterized in that At the bonding temperature, the elongation at break of the substrate is greater than or equal to 10%.

4. The laminating film according to claim 2, It is characterized in that The substrate also satisfies at least one of the following conditions: The softening temperature of the substrate is greater than or equal to a predetermined temperature, and the predetermined temperature is the lamination temperature -30°C; The substrate is treated at the laminating temperature for a predetermined time, and the morphology and color of the substrate remain unchanged.

5. The laminating film according to claim 2, It is characterized in that The substrate also satisfies at least one of the following conditions: The light transmittance of the substrate is greater than or equal to 90%; The haze of the substrate is less than or equal to 1%; The in-plane phase retardation of the substrate is less than or equal to 10 nanometers.

6. The laminating film according to any one of claims 1 to 4, It is characterized in that The substrate includes at least one of polymethyl methacrylate, polycarbonate, triacetyl cellulose, cycloolefin polymer, cycloolefin copolymer, polyester, polypropylene, polyethylene, polyolefin, polyimide, thermoplastic polyurethane and polyvinyl chloride.

7. The laminating film according to claim 1, It is characterized in that The viscosity-reducing adhesive layer satisfies at least one of the following conditions: The thickness of the viscosity-reducing adhesive layer is 0.1 to 20 microns, and the thickness deviation at different positions is less than or equal to 5%; The viscosity-reducing adhesive layer includes at least one of acrylic adhesive, epoxy adhesive, organic silicone adhesive and polyurethane adhesive; The coating method for forming the viscosity-reducing adhesive layer includes at least one of slit coating, micro-concave coating, and blade coating.

8. The laminating film according to claim 7, It is characterized in that The viscosity-reducing adhesive layer also satisfies at least one of the following conditions: The peeling force between the adhesive layer and the adhesive film layer before the adhesive layer is greater than or equal to 1000gf / cm 2 ; The peeling force between the debonding adhesive layer and the adhesive film layer after debonding is less than or equal to 100gf / cm 2 .

9. The laminating film according to claim 7 or 8, It is characterized in that The anti-viscosity adhesive layer is a UV anti-viscosity adhesive layer, and the UV anti-viscosity adhesive layer meets at least one of the following conditions: The wavelength of UV light is 365nm to 410nm; The light intensity density received by the adhesive surface of the UV adhesive layer is greater than or equal to 2000mJ / cm 2 .

10. The laminating film according to claim 9, It is characterized in that The UV viscosity-reducing adhesive layer also satisfies at least one of the following conditions: The UV viscosity-reducing adhesive layer has a tolerance time of not less than 3 minutes at the lamination temperature; When the thickness of the UV anti-viscosity adhesive layer is 100 micrometers, the light transmittance of the UV anti-viscosity adhesive layer is greater than or equal to 90%, and the haze is less than or equal to 1%.

11. The laminating film according to claim 1, It is characterized in that The release protective film meets at least one of the following conditions: The thickness of the release protective film is 5 to 100 microns; The surface roughness Ra of the release protective film is less than or equal to 0.5 micrometers; The residual bonding rate of the release protective film is greater than or equal to 90%; The peeling force between the release protective film and the viscosity-reducing adhesive layer is less than or equal to 200 gf / cm 2 .

12. A method of laminating, It is characterized in that include: Providing a first laminating film, wherein the first laminating film is the laminating film according to any one of claims 1 to 11, and removing a release protective film of the first laminating film; Providing a first optical functional layer, wherein the first optical functional layer comprises a first functional layer body and a first adhesive layer which are stacked; Laminating the surface of the viscosity-reducing adhesive layer of the first laminating film to the surface of the first functional layer body away from the first adhesive layer to obtain a first composite layer body; Provide a lens and a bonding groove, wherein the bonding groove comprises an upper bonding groove and a lower bonding groove, wherein the lens matches the bonding surface of the upper bonding groove and the bonding surface of the lower bonding groove respectively, and place the lens on the bonding surface of the lower bonding groove; Placing the first composite layer on a side of the lens away from the lower bonding groove, and arranging the first adhesive layer close to the lens; Heating the temperature to a bonding temperature to soften the first composite layer, and bonding the upper bonding groove to the first composite layer and performing a lamination process; The fitting groove is removed.

13. The method according to claim 12, It is characterized in that Also includes: Providing a second laminating film, wherein the second laminating film is the laminating film according to any one of claims 1 to 11, and removing the release protective film of the second laminating film; Providing a second optical functional layer, wherein the second optical functional layer comprises a second functional layer body and a second adhesive layer which are stacked; Laminating the surface of the viscosity-reducing adhesive layer of the second laminating film to the surface of the second functional layer body away from the second adhesive layer to obtain a second composite layer body; Placing the other surface of the lens on the bonding surface of the lower bonding groove, and placing the substrate of the first bonding film in contact with the bonding surface of the lower bonding groove; Placing the second composite layer on a side of the lens away from the lower bonding groove, and arranging the second adhesive layer close to the lens; Heating the temperature to the bonding temperature to soften the second composite layer, and bonding the upper bonding groove to the second composite layer and performing a lamination process; The fitting groove is removed.

14. The method according to claim 13, It is characterized in that Also includes: irradiating the substrate surface of the first laminating film and the substrate surface of the second laminating film with UV light respectively, so that the peeling force of the viscosity-reducing adhesive layer of the first laminating film and the viscosity-reducing adhesive layer of the second laminating film is reduced; The viscosity-reducing adhesive layer of the first laminating film and the substrate are peeled off, and the viscosity-reducing adhesive layer of the second laminating film and the substrate are peeled off.

15. The method according to claim 13 or 14, It is characterized in that The first functional layer body includes at least one of a wavelength phase retardation film, a reflective polarization film, and a linear polarization film, and the second functional layer body includes at least one of the wavelength phase retardation film, the reflective polarization film, and the linear polarization film.

16. The method according to any one of claims 12 to 14, It is characterized in that The laminating temperature is 100-130°C.

17. A folded light path lens, It is characterized in that The invention comprises a lens and an optical function layer, wherein the optical function layer is bonded to the surface of the lens, and the bonding method is achieved by the method according to any one of claims 12 to 16.

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