Packaging body of heat-bent polarizing plate

Abstract

The present invention provides a package of a heat-bent polarizing plate which does not require pre-drying before injection molding and does not require peeling-off operation of a protective film even after storage (storage, transfer, transportation) and the like. A package of a heat-bent polarizing plate which is a stacked polarizing plate for manufacturing an injection polarizing lens, in which a transparent plastic sheet is bonded to both sides of a polarizing film composed of a uniaxially stretched polyvinyl alcohol-based resin film via an adhesive layer as a single stacked polarizing plate in a single lens raw sheet shape, is heat-bent into a spherical or aspherical surface under heating to produce a heat-bent polarizing plate, which is mounted on a mold and injection molded with a transparent lens resin on the concave surface thereof, wherein the package stacks the heat-bent polarizing plate via a non-adhesive separating film and performs moisture-proof packaging for storage or transportation, and can be used for injection molding without substantially performing pre-drying as a pre-treatment before injection molding and peeling-off operation of a protective film.

Description

[0001] This case is a divisional application filed on September 7, 2018, with application number 201880059173.7 (PCT / JP2018 / 033214), entitled "Packaging for Heat-Bending Polarizing Film and Injection Polarizing Lens". Technical Field

[0002] This invention relates to injection-molded polarizing lenses made of transparent resin for use in sunglasses or goggles with anti-glare properties, and also to packaging for the injection-molded heat-bending polarizing film. Background Technology

[0003] Currently, practical polarizing plates typically use polarizing films obtained by adsorbing or impregnating iodine or bichromatic organic dyes onto a uniaxially stretched polyvinyl alcohol (PVA) film. These polarizing films usually have a transparent resin such as triacetyl cellulose as a protective layer on one or both sides, and are considered easy to process, suitable for secondary processing, inexpensive, and lightweight.

[0004] In applications requiring impact resistance, such as polarized lenses for sunglasses, they are typically manufactured as follows: a multilayer polarizing film is made using a polarizing film layer of bichromatic organic dye or a functional layer such as a photochromic layer, and an aromatic polycarbonate sheet or film as a protective layer. This film is then punched into the desired shape and heat-bent into a partially spherical surface. The concave side of the film is then injection molded with aromatic polycarbonate for lens production to form a polarized lens (hereinafter referred to as an injection polarized lens). Appropriate surface treatments are then performed to manufacture the polarized lens.

[0005] Its production process is based on: (1) manufacturing of polarizing film and its stacked polarizing film; (2) punching and hot bending of stacked polarizing film; (3) injection molding of aromatic polycarbonate and appropriate surface treatment.

[0006] Moreover, (4) in stores, they are processed into various lens shapes and sold as sunglasses.

[0007] Typically, each process is carried out independently, during which time items are stored, preserved, transferred, transported, and distributed. Additionally, even within the same production location, items may be temporarily stored and preserved due to production plans or other circumstances.

[0008] When the multilayer polarizer prepared in (1) is processed, processed, etc., its surface is coated with a protective film to protect its surface from scratches, stains and foreign matter.

[0009] As a protective film, especially as a protective film that can withstand hot bending processing in high-temperature environments near the glass transition temperature of aromatic polycarbonates, a polyolefin-based protective film has been proposed (Patent Documents 1 and 2).

[0010] In (2), while maintaining the state of having the above-mentioned protective film, the blanking process is carried out, and the pre-drying is carried out as a pretreatment to produce a hot-bent product. Multiple overlaps are then bundled together appropriately.

[0011] In addition, in (3), drying is performed, the protective film is peeled off, and it is installed on the mold for injection molding of aromatic polycarbonate.

[0012] In terms of drying, (2) is carried out to suppress color changes during hot bending processing, while (3) is carried out to suppress color changes during injection molding.

[0013] Furthermore, since the polarizing layer becomes brittle during drying, the die-cutting process is usually performed before drying. In some cases, there are methods to allow it to absorb moisture to a certain extent in a high-humidity room (Patent Document 3), and methods using higher molecular weight polyvinyl alcohol have also been proposed (Patent Document 4).

[0014] Furthermore, the inventors of this invention previously proposed a packaging body that does not require pre-drying in the above-mentioned process (3) and an injection polarizing lens using the packaging body (Patent Document 5).

[0015] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2003-145616 Patent Document 2: Japanese Patent Application Publication No. 2011-110879 Patent Document 3: Japanese Patent Application Publication No. 5-119216 Patent Document 4: Japanese Patent Application Publication No. 2008-262104 Patent Document 5: WO2016 / 067937A1 Summary of the Invention

[0016] The problem that the invention aims to solve The subject of this invention is to further extend the proposal of Patent Document 5, which states that pre-drying before injection molding is not required even after storage (preservation, transfer, transportation), etc.

[0017] In the aforementioned existing technology, various production processes are accompanied by storage and transportation. Their storage environments are typically ordinary warehouses, without humidity or temperature control. Therefore, these environments vary depending on geographical location and seasonal factors; however, assuming indoor warehouse storage, the storage environment can be considered to be approximately -10℃ to 40℃ and humidity between 5% and 90%.

[0018] From a production efficiency perspective, the storage period is usually short. However, due to factors such as changes in demand, if the product cannot be used for a short period of time, it may sometimes need to be stored for about one month, and in longer-term cases, up to about six months, or even more than six months.

[0019] The heat-bending polarizing film absorbs moisture during storage and handling under the aforementioned conditions. Therefore, to suppress color changes caused by injection molding of the moisture-absorbing heat-bending polarizing film, pre-drying as a pretreatment is necessary. Currently, this pre-drying is typically performed at 60–80°C, preferably 65–75°C, for 5–24 hours, selecting appropriate conditions to achieve a level of drying that does not cause color changes that would be problematic during injection molding. However, this process becomes very complex and slow, impacting production efficiency; therefore, improvements to these pretreatment methods are desired.

[0020] The inventors of this invention requantified the relationship between the moisture content of the hot-bending polarizer and the color change during injection molding, as well as the relationship between the moisture content of the hot-bending polarizer and the partial pressure of water vapor in the surrounding gas. Furthermore, they discovered a packaging for the hot-bending polarizer that maintains the moisture content allowed for color change, and an injection-firing polarizing lens for use with the packaged hot-bending polarizer without pre-drying. Based on these findings, the invention was first completed and filed.

[0021] Further research was conducted in relation to this invention, resulting in the discovery of a more labor-saving manufacturing process, thus completing this invention.

[0022] Methods for solving problems That is, the content of this invention is as follows.

[0023] (1) A packaging body for a heat-bent polarizing film, wherein the packaging body overlaps the heat-bent polarizing film for injection molding with a non-adhesive insulating film and is then stored or transported in a moisture-proof manner, wherein, It can be used for injection molding without pre-drying as a pretreatment for injection molding and without substantially removing the protective film.

[0024] As described below, the aforementioned polarizer is a laminated polarizer consisting of a polarizing film made of uniaxially stretched polyvinyl alcohol resin film, with transparent plastic sheets bonded to both sides through an adhesive layer. This laminated polarizer, used as a separate lens, is thermally bent into a spherical or aspherical surface under heat to create a thermally bent polarizer. This polarizer is then mounted onto a mold, and transparent lens resin is injection molded onto its concave surface to obtain an injection-molded polarized lens.

[0025] In this invention, the aforementioned hot-bendable polarizers are stacked with a non-adhesive insulating film and then stored or transported after being packaged in a moisture-proof manner. This provides a package for injection-molded hot-bendable polarizers that can be substantially used without the aforementioned pre-drying and protective film peeling operations before injection molding, and an injection-molded polarizing lens using this package.

[0026] In the invention described in (1) above, (2) The moisture content of the hot-bending polarizing film after packaging is less than 0.35 wt%, preferably less than 0.3 wt%; (3) The water vapor content of the internal gas of the above-mentioned packaging body is 15 g / m³. 3 The preferred value is 14 g / m³. 3 Below. And, (4) The above-mentioned transparent plastic sheet is a transparent plastic film or sheet with a thickness of 0.1 to 1 mm, selected from at least one of aromatic polycarbonate, polyacrylate, polyamide, acetyl cellulose, and a composition of aromatic polycarbonate and alicyclic polyester; (5) The above-mentioned packaging body is a primary packaging body and a durable secondary packaging body formed by bundling multiple primary packaging bodies. The primary packaging body is obtained by peeling off the protective film used during the hot bending process of the polarizer, and then overlapping and packaging dozens to hundreds of peeled polarizers with a non-adhesive isolation film. (6) The above-mentioned non-adhesive isolation film is selected from polyolefin films; (7) The primary packaging or durable secondary packaging shall have at least a sufficient buffer layer around it, the buffer layer being a dust-free or low-dust material or a dust-free or low-dust buffer layer obtained by covering with a dust-free or low-dust material. (8) The above-mentioned primary packaging body is obtained by storing the heat-bending polarizing film in a container that can hold it. The container is made of dust-free or low-dust raw material or is a dust-free or low-dust container obtained by covering it with dust-free or low-dust raw material. (9) The packaging materials used in the aforementioned secondary packaging are selected from one or more of the following: single-wall corrugated cardboard, double-wall corrugated cardboard, triple-wall corrugated cardboard, or plastic, plastic corrugated cardboard, etc. Furthermore, (10) Any of the above-mentioned primary or secondary packaging materials shall be made of moisture-proof packaging materials; (11) The internal air of any of the primary or secondary packaging units described above is replaced with dry air or nitrogen, or the internal pressure is reduced. Furthermore, (12) It is sealed with a desiccant, wherein the desiccant is selected from one or more of silica gel, quicklime, calcium chloride processed products, silica-alumina glue, viscous desiccant and sheet desiccant; (13) A sensor that senses the packaging status is sealed in the package, and the sensor senses the partial pressure of water vapor or oxygen. (14) It can be sealed or easily sealed after opening.

[0027] (15) In addition, the present invention provides an injection polarizing lens, characterized in that: in the invention described in (1) above, It is used for injection molding without pre-drying as a pretreatment for injection molding and without substantially performing a protective film peeling operation.

[0028] Invention Effects The hot-bending packaging of the present invention exhibits excellent performance in preventing moisture absorption during long-term storage. Even after long-term storage, it can manufacture good injection polarizing lenses without pre-drying as a pretreatment for injection molding and without substantially peeling off the protective film. Attached Figure Description

[0029] Figure 1 This is a diagram showing the general shape of the packaging of the heat-bending polarizing film of this application. Detailed Implementation

[0030] The structure of the present invention will be described below.

[0031] Polarizing film Polyvinyl alcohol-based resin film is used as the substrate film for polarizing film.

[0032] Examples of polyvinyl alcohol-based resins include polyvinyl alcohol (PVA) and its derivatives or similar compounds such as polyvinyl alcohol formaldehyde, polyvinyl alcohol acetal, and poly(ethylene-vinyl acetate) copolymer saponification, with PVA being preferred.

[0033] The weight-average molecular weight of the PVA film is 50,000 to 350,000, and preferably 150,000 to 300,000. The thickness of the raw PVA film is usually about 50 to 300 μm, and the PVA polarizing film obtained by stretching and dyeing it is usually 10 to 50 μm, preferably 20 to 40 μm.

[0034] The stretch ratio of PVA film is usually in the range of 2 to 8 times, and from the point of view of the strength after stretching, it is preferably 3 to 6.5 times.

[0035] The polarizing film (dyed and stretched PVA film) can be manufactured, for example, by stretching the above-mentioned polyvinyl alcohol film substrate in water in one direction, dyeing it with a two-color organic dye, treating it appropriately with an aqueous solution of boric acid, metal salt, etc., and then drying it.

[0036] Multilayer polarizer In this invention, a transparent protective film or sheet (hereinafter referred to as "film or sheet" simply as "sheet") is laminated to at least one side of the above-mentioned layered polarizing film to obtain a multilayered polarizing film.

[0037] Examples of transparent protective films include those made of transparent resins such as aromatic polycarbonates, amorphous polyolefins, polyacrylates, polysulfones, acetyl cellulose, polystyrene, polyesters, polyamides, and mixtures of aromatic polycarbonates and alicyclic polyesters. Among these, acetyl cellulose is essential in the manufacture of the most common polarizing films. Aromatic polycarbonate resins are preferred based on properties such as mechanical strength and impact resistance. Polyolefins, polyacrylates, or polyamides are preferred based on chemical resistance. Polyacrylates or polyamides are preferred based on the dyeability of the lens after molding.

[0038] In the case of aromatic polycarbonate sheets, from the viewpoints of film strength, heat resistance, durability, or flexural processability, polymers made by known methods from bisphenol compounds, represented by 2,2-bis(4-hydroxyphenyl)alkanes or 2,2-(4-hydroxy-3,5-dihalophenyl)alkanes, are preferred. The polymer backbone may contain structural units derived from fatty acid diols and / or structural units having ester bonds. Aromatic polycarbonates derived from 2,2-bis(4-hydroxyphenyl)propane are particularly preferred.

[0039] The molecular weight of the aromatic polycarbonate, based on viscosity-average molecular weight, is preferably 12,000 to 40,000, more preferably 20,000 to 35,000. Furthermore, aromatic polycarbonates have a high photoelastic constant and are prone to colored interference fringes or white spots due to birefringence caused by stress and orientation. Therefore, it is preferable to eliminate white spots by having a large retardation value beforehand, making the colored interference fringes invisible. The retardation value is 2000 nm or more and 20000 nm or less, preferably 3000 nm or more, and particularly preferably 4000 nm or more, especially considering reductions in processing steps.

[0040] The retardation value is roughly proportional to the orientation degree and the magnitude of residual stress. Therefore, higher values ​​tend to result in reduced surface shape accuracy and expansion in the direction perpendicular to the stretching direction, which is the same as the transmission axis of the polarizing film in typical laminated structures. Furthermore, blank and colored interference fringes can be seen by the human eye through the polarizing film. Therefore, the effect of a high-retardation sheet is achieved by using it on the light-incident side of the polarizing film, opposite to the human eye.

[0041] Furthermore, the thickness of aromatic polycarbonate sheets can be appropriately selected between 0.1 and 1 mm.

[0042] The alicyclic polyester resin of the present invention, which can be used as a composition with aromatic polycarbonate, as a sheet or film for protective layer, and as an injection molding resin for lens, can be obtained, for example, by the following known method: subjecting a dicarboxylic acid component, represented by 1,4-cyclohexanedicarboxylic acid, a diol component, represented by 1,4-cyclohexanediethanol, and other small amounts of other components as needed, to an esterification or transesterification reaction; then, appropriately adding a polymerization catalyst and gradually reducing the pressure in the reaction tank to carry out a polycondensation reaction.

[0043] Polyamide resins include those known as transparent polyamide resins for lenses. One indicator of heat resistance is a heat distortion temperature in the range of 100–170°C. Examples include aromatic polyamide resins, alicyclic polyamide resins, aliphatic polyamide resins, and their copolymers. From the viewpoint of balancing mechanical strength, chemical resistance, and transparency, alicyclic polyamide resins are preferred. Combinations of two or more polyamide resins are also possible. Examples of such polyamide resins include GLILAMID TR FE5577, XE 3805 (manufactured by EMS), NOVAMID X21 (manufactured by Mitsubishi Engineering Plastics), and Toyobo Nylon T-714E (manufactured by Toyobo).

[0044] (Meth)acrylate resins are homopolymers of polymethyl methacrylate (PMMA), various (meth)acrylates represented by methyl methacrylate (MMA), or copolymers of PMMA or MMA with one or more other monomers. They can also be obtained by mixing multiple of these resins. Among these, (meth)acrylates containing a cyclic alkyl structure with low birefringence, low moisture absorption, and excellent heat resistance are preferred. Examples of (meth)acrylate resins as described above include Acrypet (manufactured by Mitsubishi Rayon), Delpet (manufactured by Asahi Kasei Chemicals), and Parapet (manufactured by Kuraray).

[0045] As an adhesive for attaching a transparent plastic sheet to both sides of the polarizing film, polyvinyl alcohol resin-based materials, acrylate resin-based materials, polyurethane resin-based materials, polyester resin-based materials, melamine resin-based materials, epoxy resin-based materials, silicone-based materials, etc., can be used.

[0046] When using aromatic polycarbonate sheets, especially from the viewpoint of transparency of the adhesive layer itself or when it is already bonded and its adhesion to the aromatic polycarbonate sheets, a two-component thermosetting polyurethane resin consisting of a polyurethane prepolymer as a polyurethane resin material and a curing agent is preferred.

[0047] In addition, when using high-retardation aromatic polycarbonate sheets, they are usually manufactured by coating an adhesive solution onto a polarizing film, pre-drying to reduce the solvent, overlapping aromatic polycarbonate sheets or films, and then performing the same operation on the opposite side, and then curing under conditions that do not cause the polarizing layer to deteriorate, especially under conditions where the temperature and humidity are kept constant. In the present invention, it is also possible to manufacture a multilayer polarizing film.

[0048] The layer structure of the multilayer polarizer of the present invention is not limited to the above scope. For example, the layer structure of the multilayer polarizer obtained by appropriately dissolving a light-modifying dye, an ultraviolet absorber, an infrared absorber, or other materials in the adhesive for bonding the transparent protective layer and the polarizing film can also be used. The layer structure of the multilayer polarizer obtained by containing these functional additives in the transparent protective film can also be used.

[0049] Hot bending polarizer The above-prepared stacked polarizer is processed into a single original shape for use as a lens, forming a single stacked polarizer. It is then heated and bent into a spherical or aspherical surface to produce a hot-bent single stacked polarizer (hereinafter referred to as a hot-bent polarizer).

[0050] From a productivity standpoint, the processing of individual stacked polarizers (the original shape used for individual lenses) typically employs a die-cutting tool made from a Thomson blade to simultaneously cut multiple individual stacked polarizers. The shape of the individual stacked polarizer is appropriately selected based on the shape of the final product (sunglasses, goggles, etc.). For example, in the case of binoculars, the standard shape is a disc with a diameter of 80mm or a narrow, elongated shape with both ends cut off at the same width in a direction perpendicular to the polarization axis.

[0051] For the aforementioned proper die-cutting of individual multilayer polarizers, a certain degree of toughness is necessary.

[0052] In a laminated polarizing film using aromatic polycarbonate sheets as a protective layer (hereinafter referred to as an aromatic polycarbonate polarizing film), since the aromatic polycarbonate sheet portion is not excessively damaged during punching, the polarizing film layer, adhesive layer, and protective films on both surfaces are not significantly damaged. The presence or absence of fine fragments, crack propagation in the tensile direction, and excessive deformation becomes the focus of research. Therefore, as mentioned above, to prevent the polarizing layer from being damaged during punching due to dryness, thus preventing the generation of fine fragments, an appropriate moisture-absorbing method is recommended.

[0053] Next, after pre-drying the individual laminated polarizers, they are hot-bent into spherical or aspherical surfaces under heat to obtain hot-bent polarizers. For pre-drying, conditions are selected that do not change the color of the individual laminated polarizers after hot bending. Typically, air drying is carried out at 60–80°C, preferably 65–75°C, for at least 8 hours, preferably about 24 hours.

[0054] The hot bending process of aromatic polycarbonate polarizing films involves bending them along the surface of a mold used in injection molding. In hot bending, planar, individually stacked polarizing films are typically formed into partially spherical surfaces, or, depending on the situation, into three-dimensional curved surfaces such as ellipses. This process, which involves minimal energy during deformation, is accompanied by shrinkage. If smooth shrinkage is impeded, waves or even wrinkles may occur, making it impossible to produce acceptable products. Therefore, to ensure smooth shrinkage, it is preferable to control temperature, load, and other factors with slow, heavy-duty processes.

[0055] Regarding the heating temperature, a processing temperature can be selected that is at least 50°C lower than the glass transition temperature of the transparent plastic sheet used for the protective film and also lower than the glass transition temperature. In the case of aromatic polycarbonate polarizers, the maximum temperature of the bending die during hot bending is at least 25°C lower than the glass transition temperature of the aromatic polycarbonate, preferably at least 20°C lower, and at least 5°C lower than the glass transition temperature.

[0056] In addition, by preheating, the temperature of the aromatic polycarbonate polarizer to be bent is controlled below the temperature used for bending, so that it will not cause color change in a short time. In the case of aromatic polycarbonate polarizers, it is preferable to use a temperature that is about 25°C lower than the glass transition temperature of aromatic polycarbonate.

[0057] Packaging The packaging of the hot-bending polarizer of the present invention is a packaging of the hot-bending polarizer that first maintains the moisture content of the hot-bending polarizer at an appropriate value during a desired period, and protects the hot-bending polarizer from appearance defects such as dust or scratches.

[0058] Regarding the moisture content of the hot-bending polarizer, as shown in the examples described later, it was quantified using moisture content. The results showed that after drying immediately following the hot-bending process and before injection molding, the moisture content of the hot-bending polarizer was less than 0.15 wt%. Furthermore, when hot-bending polarizers with a moisture content exceeding 0.4 wt% were injection molded, significant color changes occurred after injection molding, causing appearance defects.

[0059] Therefore, the appropriate moisture content of the heat-bending polarizing film is 0.35 wt% or less, preferably 0.3 wt% or less. When forming the package, the heat-bending polarizing film must be sealed in at the aforementioned appropriate moisture content and maintained at that appropriate value.

[0060] Furthermore, although the rate of moisture absorption varies greatly depending on the environment, it generally begins to gradually absorb moisture when the temperature drops below 100°C, and then rapidly absorbs moisture when the temperature drops below 60-70°C. When the material used for moisture-proof bundling is a plastic raw material, it typically has a heat resistance of over 70°C. By using moisture-proof raw materials for bundling at around 60-70°C, it is possible to bundle the polarizing film at an appropriate moisture content.

[0061] The moisture content mentioned in this instruction manual is obtained by converting the moisture content measured by a barometric moisture meter (manufactured by ITS Japan, AquaTrack) into the moisture content of the sample. This measuring device involves evacuating the sample into a container, heating it, and causing the vaporized water to react with reagents (such as calcium hydride). A sensor detects the pressure of the generated hydrogen gas, and the moisture content is determined based on the sample weight.

[0062] Secondly, this packaging body is a primary packaging body obtained by peeling off the protective film used in the hot bending process of the hot bending polarizer, and then overlapping and packaging dozens to hundreds of non-adhesive isolation films, or a durable secondary packaging body obtained by bundling multiple primary packaging bodies.

[0063] The peeling of the protective film used in hot bending and the packaging with a non-adhesive barrier film are usually carried out at room temperature, which takes a certain amount of time because multiple packages are being processed.

[0064] From this perspective, the method of temporarily storing the polarizer and then packaging it in another process is a preferred example, as it can be carried out under conditions that adequately maintain the appropriate moisture content of the heat-bent polarizer.

[0065] In addition, as the aforementioned non-adhesive isolation membrane, examples can be shown of membranes made of polyolefins such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene, polybutadiene, or combinations of their comonomers.

[0066] From a production process perspective, in cases where packaging before the aforementioned moisture absorption begins is difficult, it is suitable to temporarily store the heat-bending polarizer in a low-humidity storage room to prevent moisture absorption, followed by packaging in another process. Regarding the low-humidity storage room, appropriate conditions should be selected to maintain the moisture content of the heat-bending polarizer within a suitable range. Specifically, a super dryer such as the Toyo Living Co., Ltd. SD-702-D1X can be used.

[0067] In addition, after the hot-bending polarizer is manufactured, if it absorbs moisture again, it can be dried again before use. The drying method can be selected to achieve the moisture content mentioned above, and air drying is usually carried out at a temperature below 80°C.

[0068] Furthermore, in the embodiments described later, the amount of moisture in the heat-bending polarizer and the amount of water vapor in the gas inside the packaging body in equilibrium were also quantified. The determination was performed using gas chromatography (manufactured by Shimadzu Corporation: GC-2014).

[0069] The determination of the amount of water vapor in the gas described in this specification was performed in accordance with Japanese Patent Application Publication No. 2006-145254.

[0070] As a result, when the water content of the hot-bending polarizer is 0.48 wt% or higher as an appropriate value, the water vapor content of the surrounding gas in equilibrium with it is approximately 16 g / m³. 3 .

[0071] Therefore, the water vapor content of the internal gas of the packaging is 15 g / m³. 3 The following, preferably 14g / m 3 The following is an appropriate value, which allows the moisture content of the heat-bending polarizer to be maintained at the above appropriate value.

[0072] For the gas inside the packaging, assuming transport under reduced pressure, it is preferable to pre-degas it. Furthermore, considering the cargo warehouse environment for air freight in recent years, it is not necessarily necessary to reduce the volume to the same level as under reduced pressure.

[0073] In addition, to keep the amount of water vapor inside the packaging constant, dehumidified air or nitrogen can be injected as appropriate.

[0074] The moisture-proof packaging material that can be used in this invention is a moisture-proof packaging material that is impermeable to water vapor.

[0075] Of course, the water vapor permeability of moisture-proof packaging materials varies greatly depending on the ambient temperature and water vapor pressure. However, if we consider the case of long-term exposure of packaging materials using moisture-proof packaging materials to an environment with a temperature of 40°C-90%RH, which is more stringent than the usual storage environment, then materials that exhibit certain performance under such conditions are preferred as moisture-proof packaging materials.

[0076] Specifically, the performance index of the packaging body using moisture-proof packaging materials can be calculated and used as an indicator when constructing the packaging body of the present invention. In this specification, the performance of the packaging body is considered, including the adhesive layer (adhesive tape, heat-sealed layer, etc.) used when sealing the packaging body. Furthermore, the external environment of the packaging body is assumed to be a stringent 40°C / 90% RH environment, as described above.

[0077] The performance index is obtained by summing the values ​​of water vapor permeability (Di) and surface area (Si) of the raw materials (i) constituting the container and the thickness (di) of the raw materials for each component, and then dividing the sum by the volume (V) inside the packaging body, as shown in the following formula (1).

[0078] The smaller the value of the performance index in equation (1), the smaller the humidity change inside the packaging, and the better the moisture-proof properties can be considered. Under the condition that the initial conditions are the same as the surrounding environment and the packaging is placed, the smaller the performance index, the longer the storage time. When the performance index is halved, the storage time doubles, and when the performance index becomes 1 / 10, the storage time becomes 10 times. The packaging of the present invention can be constructed in a manner that allows for the evaluation of the performance of the packaging using the aforementioned performance indices, the selection of the optimal moisture-proof packaging material for the expected storage period, and the maintenance of the internal water vapor content.

[0079] Specifically, the moisture-proof performance index using the above formula (1) is 6.092 × 10⁻⁶. －5 (hour) －1 When the packaging material is as described below, it is expected to retain the amount of water vapor in the internal gas for about 3 months. However, in real-world environments, the temperature and humidity are often lower than the aforementioned harsh conditions, in which case the moisture-proof properties can be maintained for a longer period than described above.

[0080] Furthermore, in the case of packaging with performance indices of the above values ​​or higher, it is necessary to adopt the countermeasures described later, such as simultaneously sealing in a desiccant.

[0081] The raw materials for moisture-proof packaging materials can be selected from polymer raw materials such as stretched and unstretched polypropylene, polyethylene, polyurethane, and polyethylene terephthalate. Furthermore, considering the need to prevent water vapor from permeating, it is preferable to construct the material by laminating inorganic layers or by vapor-depositing inorganic layers.

[0082] In the case of layered inorganic layers, specifically, the film has an inorganic layer with a thickness of 1μm to 50μm, preferably 3μm to 30μm, more preferably 5μm to 20μm, and preferably a metal layer. However, when the thickness of the metal layer is reduced, it is difficult to maintain water vapor impermeability due to the influence of pinholes, etc. Therefore, it is necessary to utilize multilayering of plastic raw materials or increase the overall thickness of the moisture-proof packaging material.

[0083] In addition, for moisture-proof packaging materials, it is important to select materials with sufficient strength to prevent damage caused by physical stress during transportation and storage. To improve the strength of moisture-proof packaging materials, polyethylene films or similar materials can be layered in a mesh pattern to create multiple layers.

[0084] Regarding the thickness of moisture-proof packaging materials, measures such as appropriately increasing the thickness can be taken to improve strength. Furthermore, from a productivity standpoint, when using thicker moisture-proof packaging materials and choosing a heat-sealing method, a prolonged heating time is required for heat sealing; therefore, an appropriate thickness should be selected.

[0085] Considering the performance of the packaging, a desiccant can also be appropriately sealed in.

[0086] The desiccant can be selected from silica gel, quicklime, calcium chloride processed products, aluminosilicate gel, viscous desiccant, sheet desiccant, etc., or a combination thereof.

[0087] The amount of desiccant sealed in should be adjusted appropriately according to the moisture-proof performance of the packaging. Furthermore, as mentioned above, when the moisture-proof performance of the packaging is low, maintaining the dryness inside depends on the desiccant, requiring a large amount of desiccant to be sealed in.

[0088] For example, moisture-absorbing properties can be imparted by layering a desiccant or moisture-absorbing film onto the moisture-proof packaging material. This eliminates the need for sealing in a desiccant and also eliminates the need to consider the amount of desiccant to be sealed in.

[0089] Specifically, it can use ACTIVE PACK manufactured by Fuji Gel Industries, Ltd.

[0090] sensor Even when the absorbed moisture content is above the aforementioned appropriate value, the heat-bending polarizing film will not exhibit a discoloration that is easily identifiable by visual inspection. Therefore, the moisture content of the heat-bending polarizing film must be measured using specialized equipment, or the packaged film must be removed and injection molded; quality cannot be confirmed until the manufacturing process is complete. Furthermore, if the packaging is damaged due to an accident or other reasons and cannot maintain its moisture-proof properties, it is difficult to determine the moisture content of the heat-bending polarizing film.

[0091] Therefore, it is desirable to design a sensor that can visually identify whether the packaging of a heat-bending polarizer is kept in a moisture-proof state.

[0092] The sensor can be a sensor that detects the amount of water vapor inside the packaging, or a sensor that detects the moisture content of the heat-bending polarizer sealed inside. Alternatively, it can be a sensor that detects oxygen inside, or a combination of these.

[0093] In detail, it comprises a sensor that displays the history of water vapor levels inside the packaging exceeding the aforementioned appropriate range using numerical values, color changes, or weight changes. Furthermore, from the viewpoint of displaying humidity history, an irreversible sensor is preferred. The sensor's sensitivity is appropriately adjusted to ensure a response when the water vapor level in the internal air exceeds the aforementioned appropriate range.

[0094] More specifically, substances that exhibit color changes due to their degree of moisture absorption, such as cobalt chloride or cobalt bromide, or substances that show their moisture absorption history due to weight changes caused by the moisture absorption of the hygroscopic material, can be selected, or combinations thereof can be used. More specifically, humidity indicators containing the above substances, silica gel, or combinations thereof can be used.

[0095] Furthermore, as mentioned above, when nitrogen or other gases are sealed inside the packaging, it can also be configured as a sensor that detects oxygen when air enters due to damage to the packaging caused by an accident or other reasons.

[0096] These sensors can be installed anywhere inside the moisture-proof packaging, inside the inner container, or inside the moisture-proof packaging material.

[0097] Packaging form Multiple heat-bending polarizing films are packaged using packaging materials to create a pre-primary package and a primary package. Considering durability, multiple of these pre-primary packages and primary packages are packaged using durable raw materials to create a secondary package. A buffer layer is provided in the package at any of the above stages, and moisture-proof packaging material is used on the package at any of the above stages and sealed to create a package in a load-bearing state.

[0098] The number of hot-bendable polarizing films to be packaged should generally be below a number that can maintain the moisture content of the hot-bendable polarizing films within an appropriate range from the time of opening until all of them are used up, and an appropriate number should be selected as a unit of operation, which will not be excessive. Moreover, since the mold cavity is designed so that the force generated by the high-pressure injection of resin applies a load symmetrically to the central axis and plane without causing twisting, an even number is preferred, preferably a multiple of that number as the minimum unit.

[0099] Based on the above viewpoints, a preliminary primary package can be constructed by selecting the number of packages from 10 to 400, and a primary package can be constructed by selecting from 10 to 1000.

[0100] In addition, from the perspective of improving the durability of the packaging, several to 100 of these pre-prepared primary packaging units and primary packaging units can be selected and packaged using durable packaging materials to form secondary packaging units.

[0101] The moisture-proof packaging material used in the packaging of the heat-bending polarizer of the present invention can be used at any stage of the packaging.

[0102] The packaging form becomes a state that allows for loading for transportation and storage.

[0103] Specifically, it can be made into a state in which the aforementioned pre-packaged or pre-packaged unit is packaged in a container at any stage, thereby enabling loading.

[0104] The container can be any shape, such as a tray, bag, or cylinder. Furthermore, the raw materials for the container and packaging materials can be selected from paper, low-dust or dust-free paper, corrugated paper, plastic, etc., or a combination thereof. In the injection molding process for providing the heat-bending polarizing film, since maintaining environmental cleanliness is sometimes necessary to address post-molding appearance defects, it is preferable to select raw materials such as plastics. Specific examples of containers include those made from plastic raw materials using injection molding, blow molding, vacuum molding, compression molding, blow molding, etc.

[0105] It's not impossible to use technologies that are easy to perform the same tasks as humans, given the automation and mechanization of injection molding, and the application of electronic technologies such as LSI. However, considering economic factors, machinery that is not cheaper, as simple as possible, and purely reliable is not practical.

[0106] When using machinery to install a heat-bending polarizing film onto a mold... 1) Protective films used in thermoforming and other processes need to be peeled off, and this peeling off usually requires skilled manual operation. That is, protective films that do not actually need to be peeled off are necessary.

[0107] 2) From a purely operational point of view, the thermally bent polarizer is maintained in the same position.

[0108] In addition, detachment refers to the mold installation position, which is the same location.

[0109] 3) Holding and detaching through simple operation. From this perspective, holding and detaching preferably occur at the center of the concave surface. A single-use packaging configuration is preferred, allowing this action to be performed with simple and straightforward operation.

[0110] One packaging form is, due to 1), a packaging form in which the protective film has been peeled off; due to 2), a packaging form in which it can be moved appropriately and remain in the same position; due to 3), a packaging form in which the concave side of the heat-bending polarizer can be freed when held.

[0111] The embodiments describe an example of packaging that satisfies the above requirements 1) and 2).

[0112] In this case, as shown in the attached diagram, a three-sided sealed bag is formed. That is, two overlapping portions are made in a manner with sufficient depth using a continuous peelable film of sufficient width to accommodate the heat-bending polarizer (polarizer), and their sides are sealed.

[0113] The continuous body of this three-sided sealed bag can be rolled up. Furthermore, by pulling, a continuous body with an opening on the non-sealed side is formed, which allows the polarizer to easily enter and exit, and its position can also be easily adjusted.

[0114] Next, the packaging materials that fulfill all the necessary conditions are a concave bottom support, a convex upper support, a tubular material with the strength to perform the positioning function, and a peelable film. Here is an example of packaging: Hold a cylindrical material (tube) with sufficient strength to perform positioning function upright. Use a holding accessory (bottom holder) to hold a concave bottom accessory (base material) on top of the tube. Overlap the end of a continuous peelable film of a specified width. Overlap the convex side of a heat-bending polarizer (polarizer) with its protective film removed. Move the continuous peelable film of a specified width in a two-piece overlapping manner and overlap it on the concave side of the polarizer. Lower the bottom holder by an amount equivalent to the thickness of the polarizer and the two overlapping continuous peelable films. Repeat the operation of overlapping the polarizer and the two overlapping continuous peelable films and lowering it by an amount equivalent to the thickness. After overlapping a set number of polarizers, cover it with the upper convex accessory (cover material). Appropriately package the entire package using a cylindrical or bag-shaped packaging film.

[0115] In this single-piece packaging, two overlapping, continuous peelable films are pulled out from one side, easily releasing the concave side of the uppermost multilayer of the heat-bending polarizer. Furthermore, by reversing the operation of the same device as the bottom retainer, the concave side of the released multilayer of the heat-bending polarizer can be aligned.

[0116] That is, the mounting on the mold can be achieved by using vacuum adsorption to keep the concave side of the multilayer of the packaged heat-bending polarizer in motion, or by ensuring that the position of the vacuum adsorption on the concave side of the multilayer of the packaged heat-bending polarizer does not change substantially.

[0117] To prevent damage to the polarizing film and packaging due to physical stress during transportation and storage caused by heat bending, a cushioning layer of sufficient thickness is provided on the packaging. The cushioning layer can be provided at any stage of the preparation of the primary packaging, the primary packaging, or the durable secondary packaging.

[0118] The raw materials for the buffer layer can be selected from paper, corrugated paper, plastic, etc., or a combination thereof. As mentioned above, when managing environmental cleanliness, the raw materials used for the buffer layer are preferably low-dust materials such as bubble wrap materials, which are formed on one of two polyethylene sheets and contain air within cylindrical protrusions.

[0119] The durable packaging materials used for secondary packaging are selected from single-wall corrugated cardboard, double-wall corrugated cardboard, triple-wall corrugated cardboard, or plastic, plastic corrugated cardboard, or combinations thereof.

[0120] In addition, the volume of the secondary packaging is the volume that takes into account the volume variation of the pre-packaged primary packaging and the primary packaging, which are bundled inside, assuming transportation under reduced pressure.

[0121] The packaging can be sealed using methods that are effective in maintaining its moisture-proof properties, such as heat fusion, the application of adhesive tape, or the use of zippers, or a combination thereof.

[0122] When using heat fusion welding, the temperature of the welding surface of the packaging material used for heat fusion welding must be higher than the welding temperature, and a heating time commensurate with the heat capacity must be provided. Furthermore, the surface material of the packaging material should be protected from overheating, and an appropriate temperature and heating time should be selected to avoid insufficient heating, thus preventing defects in the heat-fused seal. In addition, factors such as the raw materials used in the heat-fused layer, its thickness, and the heat-fused area are also selected considering their impact on the moisture-proof performance of the packaging.

[0123] When using adhesive tape for sealing, it is preferable to choose a material that maintains a tight seal even when exposed to the environment during storage and transportation; specifically, a water-resistant material should be selected.

[0124] In the case of zippers, a double zipper structure is preferred while maintaining sufficient airtightness.

[0125] Furthermore, to prevent moisture absorption during short-term use of the heat-bent polarizing film after the packaging is opened, measures are taken to create a resealable state through a combination of these methods. Specifically, a primary seal is formed by heat fusion of the packaging, followed by a secondary seal, such as adhesive tape or a zipper, located on the inner or outer side of the primary seal. This allows for long-term storage and preservation, and the use of a secondary seal after opening prevents short-term moisture absorption.

[0126] Injection polarizing lens The heat-bending polarizing film, which has been wrapped in moisture-proof packaging, is removed from the packaging. After the protective film is removed appropriately, it is installed on the mold. The lens is then injection molded with transparent resin to manufacture an injection polarizing lens.

[0127] Examples of transparent resins for lenses include aromatic polycarbonate, polyacrylate, acetyl cellulose, and compositions of aromatic polycarbonate and alicyclic polyester. In this invention, aromatic polycarbonate is preferred as the transparent resin for lenses. For injection molding, the resin temperature is typically 260–340°C, preferably 270–310°C; the injection pressure is 50–200 MPa, preferably 80–150 MPa; and the mold temperature is 60–130°C, preferably 80–125°C.

[0128] Typically, as a pretreatment to suppress color changes during injection molding, the heat-bending polarizer that has been stored and transported is pre-dried at 60°C to 80°C, preferably 65°C to 75°C, for 5 to 24 hours. However, the heat-bending polarizer packaged using the packaging of this specification can be supplied to the injection molding process immediately after opening without the above pre-drying.

[0129] The aromatic polycarbonate injection-molded lens prepared above is subjected to a hard coating treatment, and further subjected to a mirror coating, anti-reflective coating, etc., to obtain the product.

[0130] Regarding the material or processing conditions of the hard coating, it is necessary to ensure excellent adhesion to the aromatic polycarbonate of the surface and the substrate, or to the inorganic layers such as the mirror coating or anti-reflective coating that are subsequently applied. Based on this, the firing temperature is preferably at least 50°C lower than the glass transition temperature of the aromatic polycarbonate sheet and at least 40°C lower than the glass transition temperature and at least 15°C lower than the glass transition temperature. At a temperature about 30°C lower, the firing time required for the hard coating is approximately 0.5 to 2 hours.

[0131] The lenses produced above are processed by lens manufacturers into sunglasses or goggles as final products and then sold. In addition, various lens processing for products, such as spherical grinding, drilling, and screw fastening, are carried out at various sales stores (retail stores) to produce sunglasses or goggles for sale.

[0132] Example Preparation of the test subject Using a polarizing film made by stretching and dyeing polyvinyl alcohol, an aromatic polycarbonate sheet with a thickness of 0.3 mm is glued to both sides of the film with the stretching axis aligned, to make an aromatic polycarbonate polarizing film with a thickness of 0.6 mm. The film is then cut into the shape of a binocular lens to obtain a single-layer polarizing film.

[0133] Next, the individual stacked polarizer is subjected to a hot bending process to obtain a hot-bent polarizer.

[0134] Hot bending uses a continuous hot bending device that includes the following steps: preheating with a preheater, placing it on a spherical part of the die with a specified temperature and a specified curvature, pressing it with a silicone rubber male die, simultaneously depressurizing it to adhere to the female die, pulling up the male die, and then removing the blanking sheet that has adhered to the female die after keeping it in a hot air atmosphere at a specified temperature for a specified time.

[0135] In the above, the preheating of the individually stacked polarizer is carried out at an atmosphere temperature of 138°C. The female mold is a partial spherical surface equivalent to 8R (radius of about 65.6 mm) with a surface temperature of 138°C. The pressing time of the male mold made of silicone rubber is 2 seconds. The adsorption to the female mold is carried out for 9 minutes in an atmosphere with a hot air blowing in at a temperature of 140°C.

[0136] Example 1 The protective films adhered to both surfaces of the heat-bending polarizer obtained above are peeled off, and HDPE films are used as isolation films, such as... Figure 1 The diagram shows 100 pieces overlapping.

[0137] Next, place the 100 pieces obtained above into a plastic tray and cover it to obtain a primary package. Place three of the above primary packages into a high-barrier RP system bag manufactured by Mitsubishi Gas Chemical Co., Ltd., and seal it by heat fusion while injecting dehumidified air to obtain a secondary package.

[0138] After storing the above-mentioned secondary packaging at room temperature for one month, it was packed into a corrugated cardboard box and loaded onto a car for 500km.

[0139] Next, the heat-bent polarizing film was removed from the secondary packaging and, without pre-drying, installed in the mold cavity of an injection molding machine. Injection molding was then performed using aromatic polycarbonate resin (viscosity-average molecular weight 23000, trade name: Iupilon CLS3400, Mitsubishi Engineering Plastics Co., Ltd.) to obtain an injection-molded polarizing lens. The injection molding conditions were set as follows: resin temperature 310°C, injection pressure 125 MPa, holding pressure 63 MPa, mold temperature 80°C, and injection cycle 70 seconds.

[0140] The injection polarizing lens was evaluated for scratches, stains, and foreign matter, and none were found. The color also did not change, indicating that it was usable as a product and had a good appearance.

[0141] Furthermore, it is possible to take out the hot-bending polarizer while simultaneously winding the insulating film, and to use an automatic machine to hold and transfer the hot-bending polarizer by vacuum adsorption from the concave side, and to install it into the mold cavity of an injection molding machine.

[0142] Example 2 Except that the insulating film is made of vinylidene chloride, the injection polarizing lens was obtained following the same steps as in Example 1. The injection polarizing lens developed stains and was unsuitable as a product.

[0143] Example 3 Except that the insulating film is made of thick paper, the injection polarizing lens was obtained following the same steps as in Example 1. The injection polarizing lens had scratches, stains, and foreign matter, making it unsuitable as a product.

[0144] Example 4 Except that the insulating film is made of thin paper, the injection polarizing lens was obtained following the same steps as in Example 1. The injection polarizing lens had scratches, stains, and foreign matter, making it unsuitable as a product.

[0145] Example 5 Except for not using a separating film, injection molding was attempted following the same steps as in Example 1. However, multiple hot-bent polarizing films were tightly adhered together, making them unsuitable for injection molding. Furthermore, when the films were separated, injection-molded polarizing lenses were obtained, but they were scratched and unsuitable as products.

[0146] Example 6 Except that the separator film is LDPE, the injection polarizing lens was obtained following the same steps as in Example 1. The injection polarizing lens was free of scratches, stains, foreign matter, and color changes, and was of a usable quality with a good appearance.

[0147] Table 1 .

Claims

1. A packaging body for a heat-bending polarizing film, characterized in that, The packaging includes heat-bending polarizing films. The packaging is formed by overlapping multiple heat-bending polarizing films separated by a continuous, non-adhesive insulating film and then moisture-proofing them. The multiple heat-bending polarizing films are laminated with a protective film on top of a layered polarizing film with transparent plastic sheets bonded to both sides of the polarizing film through an adhesive layer. This process is used for injection molding. After die-cutting and heat-bending, the protective film is peeled off to form the heat-bending polarizing film. The plurality of heat-bending polarizers are held in a state of overlapping with the continuous non-adhesive insulating film. By operating the continuous non-adhesive insulating film, one of the plurality of hot-bending polarizers can be released, and the position of the released hot-bending polarizer can be adjusted to remove it.

2. The packaging body of the heat-bending polarizing film as described in claim 1, characterized in that, The continuous, non-adhesive insulating film has a width sufficient to accommodate the heat-bending polarizer and forms two overlapping portions. The two overlapping portions are sealed on their sides, forming a three-side bag with an opening on the non-sealed side. The heat-bending polarizer is housed in the three-sided bag.

3. The packaging body of the heat-bending polarizing film as described in claim 1, characterized in that, The packaging also includes: The concave bottom auxiliary component is used to maintain the concave side of the plurality of thermally bent polarizers; The upper auxiliary member on the convex side of the plurality of thermally bent polarizers; and A cylindrical material with sufficient strength to accommodate the plurality of heat-bending polarizers and perform positioning functions. By pulling out the continuous, non-adhesive insulating film from one side, the concave side of the uppermost heat-bending polarizer can be freed. The position of the concave side of the liberated heat-bending polarizer can be adjusted by the action of at least one of the concave bottom auxiliary member and the convex upper auxiliary member.

4. The packaging body of the heat-bending polarizing film as described in any one of claims 1, 2, and 3, characterized in that, The packaged heat-bending polarizer has a moisture content of less than 0.35 wt%.

5. The packaging body of the heat-bending polarizer as described in any one of claims 1, 2, and 3, characterized in that, The water vapor content of the internal gas of the packaging body is 15g / m³. 3 the following.

6. The packaging body of the heat-bending polarizer as described in any one of claims 1, 2, and 3, characterized in that, The transparent plastic sheet is a transparent plastic film or sheet with a thickness of 0.1 to 1 mm, selected from at least one of aromatic polycarbonate, polyacrylate, polyamide, acetyl cellulose, and a composition of aromatic polycarbonate and alicyclic polyester.

7. The packaging body of the heat-bending polarizing film as described in any one of claims 1, 2, and 3, characterized in that, The packaging body is a durable secondary packaging body formed by bundling multiple primary packaging bodies. The primary packaging is obtained by peeling off the protective film used during the hot bending process of the polarizer, and then overlapping and packaging dozens to hundreds of peeled polarizers with a non-adhesive isolation film.

8. The packaging body of the heat-bending polarizing film as described in any one of claims 1, 2, and 3, characterized in that, The non-adhesive isolation membrane is selected from polyolefin membranes.

9. The packaging body of the heat-bending polarizing film as described in claim 7, characterized in that, The primary or secondary package has at least a sufficient buffer layer around it, the buffer layer being a dust-free or low-dust raw material or a dust-free or low-dust buffer layer obtained by covering with a dust-free or low-dust raw material.

10. The packaging body of the heat-bending polarizing film as described in claim 7, characterized in that, The primary packaging is a packaging obtained by storing a heat-bent polarizing film in a container that can hold it. The container is made of dust-free or low-dust raw materials or is a dust-free or low-dust container obtained by covering it with dust-free or low-dust raw materials.

11. The packaging body of the heat-bending polarizer as described in claim 7, characterized in that, The packaging material used in the secondary packaging is selected from one or more of the following: single-wall corrugated cardboard, double-wall corrugated cardboard, triple-wall corrugated cardboard, or plastic, plastic corrugated cardboard, etc.

12. The packaging body of the heat-bending polarizing film as described in claim 7, characterized in that, Any of the primary or durable secondary packaging materials shall use moisture-proof packaging materials.

13. The packaging body of the heat-bending polarizing film as described in claim 7, characterized in that, The internal air of any package in the primary and / or secondary packaging is replaced with dry air or nitrogen, or the internal pressure is reduced.

14. The packaging body of the heat-bending polarizing film as described in claim 7, characterized in that, It contains a desiccant, which is selected from one or more of silica gel, quicklime, calcium chloride processed products, aluminosilicate, viscous desiccant and sheet desiccant.

15. The packaging body of the heat-bending polarizing film as described in claim 7, characterized in that, A sensor is sealed inside the package to sense the packaging status; the sensor senses the partial pressure of water vapor or oxygen.

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