TWI621528B - Optical film and manufacturing method for the same - Google Patents

Abstract

Optical film and manufacturing method thereof. The optical film includes an optical layer, a first material layer and a second material layer. The first material layer and the second material layer are on opposite sides of the optical layer, respectively. The moisture content of the first material layer and the second material layer is less than 4 wt%.

Description

Optical film and manufacturing method thereof

The invention relates to an optical film and a manufacturing method thereof, and in particular to an optical film obtained through a process of a reaction chamber and a manufacturing method thereof.

Optical devices, such as display devices, generally require the use of multiple optical films with different effects to obtain the desired display effect. The properties of the optical film will affect the display effect of the device.

The invention relates to an optical film and a manufacturing method thereof. The optical film has good and stable properties.

According to an aspect of the present invention, an optical film is provided, which includes an optical layer, a first material layer and a second material layer. The first material layer and the second material layer are on opposite sides of the optical layer, respectively. The moisture content of the first material layer and the second material layer is less than 4%. The preferred water content is 2% ~ 3%. Wherein, the water content is Gravimetric water content.

According to an aspect of the present invention, a method for manufacturing an optical film is provided, which includes the following steps. Form a buildup. The laminate includes a substrate and a material layer On at least one side of the substrate. The laminate was passed through a reaction chamber. The reaction chamber has a humidity of 25% or less or 60% or more.

In order to have a better understanding of the above and other aspects of the present invention, preferred embodiments are described below in detail as follows:

102, 202‧‧‧ Optical diaphragm

104, 204‧‧‧ optical layer

106A, 206A‧‧‧First material layer

106B, 206B‧‧‧Second material layer

108, 308‧‧‧ reaction chamber

110, 210, 310‧‧‧ Wheel

112, 312‧‧‧ entrance side

114, 314‧‧‧ exit side

207‧‧‧Protective film

208‧‧‧ peeling film

211A, 211B‧‧‧Glue coating device

217, 219‧‧‧lighting device

302‧‧‧adhesive diaphragm

304‧‧‧ substrate

215A, 215B, 306‧‧‧Adhesive layer

316‧‧‧ Dehumidifier

FIG. 1 illustrates an optical film and a manufacturing method thereof according to an embodiment.

FIG. 2 illustrates a method for manufacturing an optical film according to an embodiment.

FIG. 3 illustrates a method for manufacturing an optical film according to another embodiment.

FIG. 4 illustrates a method for manufacturing an optical film according to an embodiment.

FIG. 5 illustrates an optical film and a manufacturing method thereof according to an embodiment.

FIG. 6 illustrates an optical film and a manufacturing method thereof according to another embodiment.

FIG. 7 illustrates a method for manufacturing an optical film according to another embodiment.

The embodiment of this disclosure proposes an optical film and a manufacturing method thereof, wherein the manufacturing method is to process a laminate including a substrate and a material layer through a reaction chamber whose humidity is controlled below 25% or above 60%, thereby obtaining Optical film of desired properties.

This disclosure does not show all possible embodiments, and other implementation aspects not proposed in this disclosure may also be applicable. Moreover, the dimensional proportions in the drawings are not drawn according to the actual products. Therefore, the contents of the description and the drawings are only used to describe the embodiments, and not used to limit the scope of the disclosure. In addition, implement The descriptions in the examples, such as the detailed structure, process steps, and material applications, are for illustration purposes only, and are not intended to limit the scope of the disclosure to be protected. The details of the steps and structures of the embodiments can be changed and modified according to the needs of the actual application process without departing from the spirit and scope of the present disclosure. The following uses the same / similar symbols to indicate the same / similar components for explanation.

1 and 2 illustrate a method for manufacturing an optical film according to an embodiment. In this example, the laminated optical film 102 includes a substrate-based optical layer 104 and a material layer including a first material layer 106A and a second material layer 106B on opposite sides of the optical layer 104 as shown in FIG. 1. In one embodiment, the optical film 102 may further include other single or multiple protective or functional optical film layers, and is not limited to this embodiment. For example, the optical film 102 may be a polarizing plate. The optical layer 104 can be a polarizer, and the material can be a polyvinyl alcohol (PVA) resin film, which can be made by saponifying a polyvinyl acetate resin. Examples of the polyvinyl acetate resin include a single polymer of vinyl acetate, that is, polyvinyl acetate, and a copolymer of vinyl acetate and other monomers capable of copolymerizing with vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids (e.g. acrylic acid, methacrylic acid, ethyl acrylate, propyl n-acrylate, methyl methacrylate), olefins (e.g. ethylene, propylene, 1 -Butene, 2-methylpropene), vinyl ethers (e.g. ethyl vinyl ether, methyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether), unsaturated sulfonic acids (e.g. vinyl sulfonic acid, vinyl Sodium sulfonate) and so on.

The first material layer 106A and the second material layer 106B may be a protective layer of a polarizing plate, and a material thereof may be selected from the group consisting of a cellulose resin, an acrylic resin, and an amorphous material. Polyolefin-based resin, polyester-based resin, polycarbonate-based resin, and combinations thereof, may specifically include polymethylmethacrylate (PMMA), and cellulose-based resin means that some of the hydroxyl groups in cellulose are acetic acid Esterified resins, or mixed esters partially acidified and partially acidified. The cellulose resin is preferably a cellulose ester resin, more preferably an ethyl cellulose resin, such as triethyl cellulose, diethyl cellulose, cellulose acetate propionate, cellulose Acetate butyrate, etc., are fully esterified cellulose called triacetate cellulose (TAC), acrylic resin film, polyaromatic hydroxy resin film, polyether resin film, cyclic polyolefin resin film (such as poly Borneene resin film), polycarbonate resins such as polyesters formed from carbonic acid and diols or bisphenols, such as: Polyethylene Terephthalate (PET), Polypropylene (PP) ), Polyethylene (PE), amorphous polyolefin resins such as cyclic olefin (co) polymers (COC / COP), from norbornene, cyclopentadiene A group consisting of ring-opening polymers such as dicyclopentadiene, tetracyclododecene, or copolymers with olefins, polycarbonate (PC), and any combination of the foregoing.

For example, the first material layer 106A and the second material layer 106B may further include a photo-curable adhesive material, or other suitable materials. The photo-curable adhesive material is selected from the group consisting of acrylic resin, polyester resin, polycarbonate resin, and amorphous polyolefin resin. The photo-curable adhesive material may include a photopolymerizable compound. The photopolymerizable compound used is not particularly limited, and examples thereof include polyester acrylate, urethane acrylate, polybutadiene acrylate, organic Silicone acrylate, epoxy acrylate and other acrylic monomers; hydrogenated epoxy monomers, alicyclic epoxy monomers, aliphatic epoxy monomers and other epoxy monomers, epoxy acrylate prepolymer Materials, acrylate prepolymers, urethane acrylate prepolymers, aliphatic urethane acrylate prepolymers, aromatic urethane acrylate prepolymers, polyester acrylate prepolymers, etc., and can be used alone or in combination. More than one of the above materials.

In one embodiment, before passing the optical film 102 through the reaction chamber 108 (FIG. 2), the first material layer 106A and the second material layer 106B may be cured, and pasted by an adhesive layer (not shown). Bonded to the optical layer 104 to form an optical film 102.

Please refer to FIG. 2. In the embodiment, the laminated layer (the optical film 102 that has not yet passed through the reaction chamber 108) is transferred from the entrance side 112 of the reaction chamber 108 into the reaction chamber 108 via the roller 110 and reacts to form an optical film (that is, after the reaction The optical diaphragm 102) behind the chamber 108, and leaves the reaction chamber 108 at the exit side 114 of the reaction chamber 108.

It is found in some embodiments that the first material layer 106A and the second material layer 106B on the opposite side of the optical film 102 (such as a stretched polarizing plate) have different moisture permeability properties. Insufficient moisture absorption time in the chamber 108 will cause a difference in the moisture content of the first material layer 106A and the second material layer 106B, and the moisture content of at least one of them will not be saturated, which will cause the optical film obtained after passing through the reaction chamber 108 The first material layer 106A and the second material layer 106B of the 102 continue to absorb moisture in an unbalanced state of moisture content in the environment outside the reaction chamber 108, which easily generates wavy patterns in the optical film 102 and affects the optical properties.

In the embodiment, the first material layer 106A and the second material layer 106B of the optical film 102 are controlled to absorb moisture during passing through the reaction chamber 108, for example, to make the moisture content reach a saturation state, thereby obtaining The first material layer 106A and the second material layer 106B of the optical film 102 are in a state of water content balance, which can prevent the optical film 102 from generating wavy patterns and have good optical properties.

In the embodiment, for example, the humidity of the reaction chamber 108 is controlled above 60%, for example, the humidity is 60% to 86%, or 60% to 70%. The reaction temperature of the reaction chamber 108 is set at 30 ° C to 40 ° C. The residence time of the optical film 102 in the reaction chamber 108 ranges from 60 seconds to 160 seconds, for example, 72 seconds. The moving speed of the optical film 102 in the reaction chamber 108 is 25 to 50 m / min. The path length of the optical film 102 in the reaction chamber 108 is 20 to 80 m. For example, the above-mentioned parameter range can efficiently make the first material layer 106A and the second material layer 106B sufficiently absorb moisture, and at the same time avoid the problem of reduced productivity caused by excessively long residence time.

For example, after the optical film 102 reacts through the reaction chamber 108, the moisture content of the first material layer 106A and the second material layer 106B is less than 4%, preferably 2% to 3%. The moisture content described herein is Gravimetric water content.

In one embodiment, for example, before the optical film 102 reacts through the reaction chamber 108, the (front) moisture content of the first material layer 106A and the second material layer 106B is 1.5% to 2.1%, and passes through the reaction chamber. After the 108 reaction, the (back) moisture content of the first material layer 106A and the second material layer 106B is increased to 2.13% to 2.6%.

The following is an example of various material layers passing through the reaction chamber 108 according to the embodiment The moisture content before and after is shown in Table 1. Among them, a change in the water content is generated, which is the (back) water content after passing through the reaction chamber minus the (front) water content before passing through the reaction chamber. The range of the aforementioned moisture content is 0.1% to 0.5%, and the preferred range is 0.25% to 0.35%.

FIG. 3 illustrates a method for manufacturing an optical film according to another embodiment. The difference from the method of FIG. 2 is mainly that in this example, the moving path of the optical film 102 in the reaction chamber 108 is short. The process parameters can be adjusted correspondingly according to the movement path, so that the moisture content of the first material layer 106A and the second material layer 106B (Figure 1) is saturated, and the optical film 102 is prevented from generating wavy patterns and has good optical properties.

The disclosure is not limited to the embodiments described in FIG. 1 to FIG. 3, and the process and structure may be changed according to the concept of the disclosure.

4 to 5 illustrate a method for manufacturing an optical film according to another embodiment. Please refer to FIG. 4 and FIG. 5 at the same time, and provide a first material layer 206A, an optical layer 204, and a second material layer 206B, respectively.

Please refer to FIG. 4 and FIG. 5 at the same time. The first material layer 206A can be transferred through the roller 210 to apply the adhesive layer 215A on the first material layer 206A through the glue application device 211A. In addition, the second material layer 206B can be conveyed through the roller 210 to apply the adhesive layer 215B on the second material layer 206B via the gluing device 211B. Of course After that, the first material layer 206A, the optical layer 204, and the second material layer 206B are transferred through the roller 210 for lamination, so that the first material layer 206A and the second material layer 206B are respectively pasted by the adhesive layer 215A and the adhesive layer 215B. The optical film 202 is formed on the opposite side of the optical layer.

The optical layer 204 may be a polarized photon, and the material may be a polyvinyl alcohol (PVA) resin film. The source is as disclosed in the previous paragraph, and details are not described herein again.

The first material layer 206A and the second material layer 206B may be protective layers of a polarizing plate, and the materials thereof are disclosed in the foregoing paragraphs, and will not be described again. In one embodiment, for example, the first material layer 206A includes cellulose triacetate, and the second material layer 206B includes a cycloolefin polymer, but the disclosure is not limited thereto.

In one embodiment, the adhesive layer 215A and the adhesive layer 215B may include a photo-curable adhesive material. The photo-curable adhesive material is disclosed in the previous paragraph, and will not be described again.

The optical film 202 can be transmitted through the roller 210 and passed through the illumination device 217 to perform the curing step. In one embodiment, the roller 210 corresponding to the illumination device 217 can provide a cooling effect on the optical film 202. The optical film 202 may be further passed through the illumination device 219 and then subjected to another curing step. The illumination device 217 and the illumination device 219 may provide, for example, UV light and the like.

In one embodiment, for example, the optical film 202 after passing through the illumination device 219 can be regarded as a laminate to be transferred in a continuous process to the reaction chamber 108 as shown in FIG. 2 and FIG. 3 to perform a humidification process so as to be located on the optical layer. The first material layer 206A and the second material layer 206B on the opposite side of 204 absorb moisture and have a balanced moisture content, and make the optical film 202 have excellent optical properties.

In an embodiment, as shown in FIG. 5, for example, a protective film 207 and a release film 208 may be disposed on the first material layer 206A and the second material layer 206B, or more optical films, such as phase Different film or brightness enhancement film, etc., to form an optical film with more layer structure, and through the adjustment of the process parameters of the reaction chamber, moisture can penetrate the other films above and enter the first material layer 206A and the second material Layer 206B, and the moisture content of the first material layer 206A and the second material layer 206B is balanced to prevent the optical film from generating wavy patterns and have good optical properties.

The material of the protective film 207 and / or the release film 208 may be selected from the group consisting of polyester resin, olefin resin, cellulose acetate resin, polycarbonate resin, acrylic resin, polyethylene terephthalate (PET), and polyethylene. Ethylene (PE) or polypropylene (Polypropylene, PP), cycloolefin resin, or a combination thereof.

For example, the first material layer 206A, the second material layer 206B, and / or other films may be optical gain, alignment, compensation, steering, orthogonal, diffusion, protection, anti-adhesion, scratch resistance, anti-glare, reflection suppression Layers that are helpful such as high refractive index can be, for example, alignment liquid crystal layers with characteristics such as controlled viewing angle compensation or birefraction, easy-to-bond treatment layers, hard coatings, anti-reflection layers, anti-adhesion layers, diffusion Layer, anti-glare layer and other surface treatment layers.

6 and 7 illustrate a method for manufacturing an optical film according to another embodiment. In this example, as shown in FIG. 6, the laminated system is an adhesive film 302, and the material layer is an adhesive layer 306 formed on a substrate 304. The material of the substrate 304 may be selected from polyester resin, olefin resin, cellulose acetate resin, polycarbonate resin, acrylic Acrylic resin, polyethylene terephthalate (PET), polyethylene (PE) or polypropylene (Polypropylene, PP), cycloolefin resin or a combination thereof. Among them, the polyester resin may be, for example, polyethylene terephthalate or polyethylene naphthalate, and the acrylic resin may be, for example, polymethyl methacrylate (PMMA). In one embodiment, the adhesive layer 306 may be a pressure sensitive adhesive (PSA), and its main component may be rubber-based, acrylic-based, silicone-based or PU-based.

Please refer to FIG. 6 and FIG. 7 at the same time. In the embodiment, the laminated layer (that is, the adhesive membrane 302 that has not passed through the reaction chamber 308) enters the reaction chamber 308 from the entrance side 312 of the reaction chamber 308 via the roller 310 to form an adhesive film. The sheet 302 leaves the reaction chamber 308 on the exit side 314 of the reaction chamber 308. In one embodiment, a plurality of consecutive reaction chambers 308 may also be included.

In some embodiments, it has been found that the adhesion of moisture to the adhesive layer 306 can cause the adhesive film 302 to whiten. In order to avoid this problem, in another embodiment, the humidity of the reaction chamber 308 is controlled below 25%, and the preferred range is 10% to 22%, thereby preventing moisture from adhering to the adhesive layer 306. The adhesive film 302 obtained according to the manufacturing method of the embodiment has no whitening problem and has stable and good properties. It is suitable for adhering various material layers, for example, for bonding the optical layer 104 and the first material layer 106A in FIG. 1 and the second layer. The material layer 106B; or used to adhere the first material layer 206A, the second material layer 206B, the protective film 207, and the release film 208 as shown in FIG.

In one embodiment, the humidity of the feed gas can be controlled by using a dehumidifying device 316 provided at the gas source to control the humidity of the reaction chamber 308. For example, dehumidification The device 316 may include a dry coil and the like. Other methods, equipment, or configurations can also be used to control the humidity of the reaction chamber 308 to effectively remove the moisture adhering to the adhesive layer 306 or to prevent outside moisture from adhering to the adhesive layer 306.

In one embodiment, the temperature of the reaction chamber 308 is controlled at 40 ° C to 50 ° C.

According to the above, in the embodiment, the humidity of the reaction chamber is controlled to be more than 60%, so that the moisture content of the material layers on the opposite sides of the optical film after passing through the reaction chamber reaches a balance, thereby preventing the optical film from generating wavy patterns. Has good optical properties. In addition, in the embodiment, the humidity of the reaction chamber can be controlled below 25%, so as to avoid the whitening problem caused by the water vapor sticking to the adhesive layer of the adhesive film.

In summary, although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the attached patent application.

Claims (12)

An optical film includes: an optical layer; and a first material layer; a second material layer, the first material layer and the second material layer are on opposite sides of the optical layer, and the first material layer One of the second material layers has a water content between 2% and 3%, wherein the water content is a weight water content. The optical film according to item 1 of the patent application scope, wherein the optical film is a polarizing plate, the optical layer is a polarizer, and the first material layer and the two material layer are selected from the group consisting of cellulose resin and acrylic Resin, amorphous polyolefin resin, polyester resin, polycarbonate resin, and combinations thereof. The optical film according to item 1 of the scope of patent application, further comprising a protective film and a release film on the first material layer and the second material layer, respectively. A method for manufacturing an optical film, comprising: forming a laminate including a substrate and a material layer on at least one side of the substrate; and passing the laminate through a reaction chamber having a humidity of 25 % Or less than 60%; wherein the residence time of the laminate in the reaction chamber is 60 seconds to 160 seconds. The method for manufacturing an optical film according to item 4 of the scope of patent application, wherein the substrate is an optical layer, and the material layer includes a first material layer and a second material layer on opposite sides of the optical layer, respectively, While the layer is passed through the reaction Before the application chamber, the first material layer and the second material layer have a first moisture content of 1.5% to 2.1%. After the laminate is passed through the reaction chamber, the first material layer and the second material layer Has a second moisture content of 2.13% to 2.6%. The method for manufacturing an optical film according to item 4 of the scope of patent application, wherein the substrate is an optical layer, and the material layer includes a first material layer and a second material layer on opposite sides of the optical layer, respectively, Before the laminate is passed through the reaction chamber, the first material layer and the second material layer have a first water content. After the laminate is passed through the reaction chamber, the first material layer and the second material have a first moisture content. The layer has a second moisture content, and a moisture content change obtained by subtracting the first moisture content from the second moisture content is 0.1% to 0.5%. The method for manufacturing an optical film according to item 5 or item 6 of the scope of patent application, wherein the humidity of the reaction chamber is 60% to 86%, and the reaction chamber has a temperature of 30 ° C to 40 ° C. The method for manufacturing an optical film according to item 5 or item 6 of the scope of patent application, wherein the moving speed of the laminate in the reaction chamber is 25 to 50 m / min, and / or the laminate is in the reaction chamber. The path length is 20 ~ 80m. According to the manufacturing method of the optical film described in item 5 or item 6 of the patent application scope, the method further includes a curing step of the material layer of the laminate before passing the laminate through the reaction chamber. The method for manufacturing an optical film according to item 5 or item 6 of the scope of patent application, wherein the material layer includes a photo-curable adhesive. The method for manufacturing an optical film according to item 4 of the scope of the patent application, wherein the optical film is an adhesive film, the material layer is an adhesive layer, and the humidity of the reaction chamber is 10% to 22%. The method for manufacturing an optical film according to item 11 of the application, wherein the adhesive layer is a pressure sensitive adhesive (PSA).