CN111073545B

CN111073545B - Method for manufacturing laminated film material and laminated film material manufactured by same

Info

Publication number: CN111073545B
Application number: CN201911165232.1A
Authority: CN
Inventors: 陈文崇; 郭建生
Original assignee: Sumika Technology Co Ltd
Current assignee: Sumika Technology Co Ltd
Priority date: 2019-02-20
Filing date: 2019-11-25
Publication date: 2022-03-25
Anticipated expiration: 2039-11-25
Also published as: TWI708685B; CN111073545A; TW202031474A

Abstract

The invention provides a method for manufacturing a laminated film material, which comprises the steps of providing a first carrier film, wherein the first carrier film is provided with an adhesive layer, and the adhesive layer contains an isocyanate compound; subjecting the first carrier film to a thickening treatment for supplying a thickener, which is a hydroxyl-containing compound reactive with an isocyanate compound, to the adhesive layer; and attaching the tackified first carrier film to the second carrier film at the adhesive side to form a laminated film material. The present application further provides a laminated film formed by the method. The invention can adjust the existing process in an economic way, and the prepared laminated film material product has the adhesive strength similar to that of a direct coating product.

Description

Method for manufacturing laminated film material and laminated film material manufactured by same

Technical Field

The present invention relates to a laminated film material technology, and more particularly to a method for manufacturing a laminated film material that can be used in the fields of a polarizing plate and a liquid crystal display, and a laminated film material manufactured by the manufacturing method.

Background

Liquid crystal displays (liquid crystal displays) have become mainstream devices in recent years because of their advantages of small size, light weight, low power consumption, and good display quality. The polarizer used therein is one of the key components in the lcd, and in order to improve the quality or production efficiency of the final product, various lcd manufacturers have various requirements for the polarizer used, such as its properties or its shipment time.

Among the above-mentioned various requirements, there are also requirements such as temporary addition or emergency supply. However, in a conventional polarizing plate manufacturing process, in order to stabilize the properties of the adhesive and achieve a desired adhesive force, the adhesive in the product must be aged after a certain period of time, and thus the polarizing plate product cannot be shipped immediately after completion. Thus, there is a need for further improvements in existing commercial NCF products, and films and subsequent products and related processes.

Disclosure of Invention

The invention aims to provide a method for manufacturing a laminated film material, which can adjust the existing process in an economic way, and can enable the manufactured product to have the adhesive strength close to that of a directly coated product.

The invention also aims to provide the laminated film material prepared by the method.

Some embodiments of the present disclosure provide a method for manufacturing a laminated film, including providing a first carrier film having an adhesive layer thereon, the adhesive layer including an isocyanate compound; subjecting the first carrier film to a thickening treatment for supplying a thickener, which is a hydroxyl-containing compound reactive with an isocyanate compound, to the adhesive layer; and attaching the tackified first carrier film to the second carrier film at the adhesive side to form a laminated film material.

Other embodiments of the present disclosure provide a laminated film material having a first carrier film, a second carrier film, and an adhesive layer. The adhesive layer is arranged between the first carrier film and the second carrier film, the adhesive layer contains isocyanate compound and hydroxyl compound capable of reacting with the isocyanate compound, and the water content of the adhesive layer is 0.8-3 wt%.

The method for manufacturing the laminated film material has the advantages that before the different film layers are attached, the adhesive layer containing the isocyanate compound is provided with the compound containing the hydroxyl group, so that the adhesive force of the adhesive layer is changed, and the laminated film material with the desired properties is obtained; therefore, the method of the invention can adjust the prior process in the most economic way on the premise of not changing the adhesive formula used by the direct painting work, and the prepared product has the adhesive strength similar to that of the direct painting work, thereby reducing the cost of the whole manufacture and management.

In order to make the features and advantages of the embodiments of the present disclosure comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

FIG. 1 is a schematic diagram of a laminated film manufacturing process according to some embodiments of the disclosure;

FIG. 2 is a schematic diagram illustrating a process of manufacturing a laminated film according to other embodiments of the disclosure;

FIG. 3 is a schematic diagram of a laminated film produced according to some embodiments of the disclosure;

FIG. 4 is a schematic diagram of a laminated film produced according to some embodiments of the disclosure;

FIG. 5 is a schematic view of a laminated film produced according to some embodiments of the disclosure;

FIG. 6 is a schematic view of a laminated film produced according to some embodiments of the disclosure;

wherein, the notation:

001 circular frame 1001 first carrier film advancing direction

1002 second carrier film advancing direction 1003 laminated film advancing direction

101 first carrier film 102 second carrier film

103 adhesive layer 104 laminated film material

105₁Release film 105₂Release film

106 polarizing plate 107 polarizing film

108₁Protective film 108₂Protective film

109 glass substrate 111 adhesion adjusting device

112, and taking up the bundle 113 drying device.

Detailed Description

The following is a detailed description of the method for manufacturing the laminated film and the laminated film manufactured by the method. It is to be understood that the following description provides many different embodiments, or examples, for implementing different aspects of embodiments of the disclosure. The specific components and arrangements described below are merely illustrative of some embodiments of the disclosure for simplicity and clarity. These are, of course, merely examples and are not intended to be limiting. Moreover, similar and/or corresponding reference numerals may be used to identify similar and/or corresponding elements in different embodiments to clearly describe the present disclosure. However, the use of such similar and/or corresponding reference numerals is merely for simplicity and clarity in describing some embodiments of the present disclosure and does not represent any correlation between the various embodiments and/or structures discussed.

It should be understood that the components or devices of the drawings may exist in a variety of forms well known to those of ordinary skill in the art. In addition, relative terms, such as "under", "lower" or "bottom" or "above …", "upper" or "top", may be used in embodiments to describe one element's relative relationship to another element of the drawings. It will be understood that if the device of the drawings is turned over and upside down, elements described as being on the "lower" side will be elements on the "upper" side. The embodiments of the present disclosure can be understood in conjunction with the accompanying drawings, which are incorporated in and constitute a part of this disclosure. It should be understood that the drawings of the present disclosure are not drawn to scale and that, in fact, the dimensions of the elements may be arbitrarily increased or reduced to clearly illustrate the features of the present disclosure.

Further, the components or devices of the drawings may exist in various forms well known to those having ordinary skill in the art. Further, it will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, or sections, these elements, components, or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure.

As used herein, the terms "about", "approximately", "substantially" generally mean within 5%, preferably within 3%, more preferably within 1%, or within 2%, or within 1%, or within 0.5% of a given value or range. The quantities given herein are approximate quantities, that is, the meanings of "about", "about" and "substantially" are implied unless otherwise specified.

In order to meet the above requirements, there are some products with no-carrier film (NCF) substrate, which first make the adhesive into a release film with both sides. Therefore, the adhesive can be cured and maintained firstly, and can be delivered after being attached to the polarizing film when needed, so that the time for waiting for the curing of the adhesive is saved.

However, the NCF products are cured in a different state, and the adhesion of the adhesive is less than that of the direct-coated products prepared by directly coating the adhesive, which results in poor quality of the subsequent products formed by the NCF products. Therefore, an adhesive with an additional tackifier (tackifier) is generally selected as the adhesive layer in the NCF to improve the adhesive force of the adhesive in the NCF, but this greatly changes the initial adhesive formula, so that it is necessary to use a different adhesive than the general coating method, thereby increasing the complexity of production or raw material management and increasing the production cost.

According to some embodiments, a method for manufacturing a laminated film that can be used in the field of a polarizing plate or a display is provided. Specifically, the carrier film having the adhesive layer is subjected to thickening treatment before being laminated with another carrier film. That is, before a carrier film having an adhesive layer is laminated to another carrier film, a hydroxyl group-containing compound is provided as a thickener to the adhesive layer containing an isocyanate compound, and then the laminating step is performed to the other carrier film. By adding the procedure of providing the hydroxyl-containing compound to the adhesive layer in the process, the amount of crosslinking (or the degree of crosslinking) of the adhesive layer can be adjusted to obtain a laminated film material with desired adhesive strength without changing the adhesive formula used initially.

Referring to fig. 1 and 2, fig. 1 and 2 are schematic views illustrating a method for manufacturing a laminated film according to some embodiments of the disclosure. The following will describe the manufacturing method of the laminated film material in detail with reference to the accompanying drawings. It should be noted that one of ordinary skill in the art can appreciate that in some embodiments, additional processing steps can be provided before, during, and/or after the laminated film manufacturing process. In different embodiments, some of the described stages (or steps) may be adjusted, deleted, or substituted as appropriate, or the order of the steps may be interchanged as appropriate.

Please refer to fig. 1, which is a schematic diagram of a manufacturing method of the laminated film 104 according to some embodiments. Generally, as shown in fig. 1, a laminated film material is continuously manufactured by continuously winding and conveying a long raw material film and performing processes of respective steps. However, the production method of the present invention is not limited to the continuous production method using such a long raw material film, and other methods such as batch production may be used.

In some embodiments, the first carrier film 101 is transported along the first carrier film running direction 1001 by a transport device, such as a guide roller, and the first carrier film 101 is subsequently laminated to the second carrier film 102. The circle 001 is a schematic diagram of a partially enlarged structure of the first carrier film 101, the first carrier film 101 has an adhesive layer 103 thereon, and the adhesive layer 103 contains an isocyanate compound, which can be used as a bridging agent for the adhesive layer 103. In some embodiments, the adhesive layer 103 does not contact the delivery device as it is delivered in order not to damage the adhesive layer 103 or to avoid contamination of the delivery device.

Before the first carrier film 101 having the adhesive layer 103 is bonded to the second carrier film 102 to be bonded, the first carrier film 101 is subjected to thickening treatment by passing through an adhesive force adjusting device 111. The adhesive agent layer 103 is supplied with a compound containing a hydroxyl group by the adhesive force adjusting device 111, and then the first carrier film 101 is bonded to the second carrier film 102 conveyed along the second carrier film traveling direction 1002 on the side of the adhesive agent layer 103 containing a hydroxyl group compound, thereby forming a laminated film material 104. The hydroxyl-containing compound in the adhesive layer 103 reacts with the isocyanate group (-NCO) of the isocyanate compound, thereby reducing the amount of bridges generated by the isocyanate bridging agent, reducing the hardness of the adhesive layer 103, and allowing the adhesive layer to be attached to the second carrier film 102 in a better fit manner, thereby achieving the purpose of improving the adhesive force. The laminated film 104 may be subjected to a subsequent process or a rolling process. In some embodiments, the laminate film 104 travels along the laminate film travel direction 1003 and is then wound into the winding bundle 112.

In some embodiments, adhesive layer 103 can be formed from an adhesive, which can be a Pressure Sensitive Adhesive (PSA), the composition of which can be of various compositions known in the art, including, but not limited to: [A] the main agent, [ B ] a crosslinking agent and optionally an [ C ] silane coupling agent, each composition of which will be described below.

[A] A main agent: the base agent may comprise at least one (meth) acrylate, hereinafter, (meth) acrylate means either acrylate or methacrylate, and the remainder of the "meth" meaning can be analogized. The (meth) acrylates may be chosen, for example, from: linear alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, n-octyl (meth) acrylate, and undecyl (meth) acrylate; or may be selected, for example, from: branched alkyl (meth) acrylates such as isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and isooctyl (meth) acrylate; or may be selected, for example, from: alkyl (meth) acrylates substituted with an alkoxy group such as 2-methoxyethyl (meth) acrylate and ethoxymethyl (meth) acrylate. In addition, the (meth) acrylate may contain an aryl group such as benzyl (meth) acrylate and the like; alternatively, the (meth) acrylate may contain aryloxy groups such as 2-phenoxyethyl (meth) acrylate, 2- (2-phenoxyethoxy) ethyl (meth) acrylate, ethylene oxide-modified (meth) acrylate of nonylphenol, 2- (o-phenylphenoxy) ethyl (meth) acrylate, and the like. The cured and dried crosslinked (meth) acrylate can be used as the main component and structure of the adhesive layer.

[B] A bridging agent: the bridging agent can help the (methyl) acrylate monomer in the main agent to generate crosslinking to form a network structure and improve the strength of the adhesive agent layer, the bridging agent has at least two functional groups in the molecule and can react with the polar functional group of the (methyl) acrylate monomer in the main agent, and the bridging agent is an isocyanate bridging agent, an epoxy bridging agent, an imine bridging agent, a metal chelate bridging agent, an aziridine bridging agent, one or a mixture of a plurality of bridging agents can be selected, but at least one isocyanate bridging agent is arranged in the adhesive agent layer 103. The total amount of the bridging agent is 0.05-10 wt%, preferably 0.1-5 wt%, of the adhesive, if the proportion of the bridging agent is too low, the adhesive can increase partial adhesive force, but the formed adhesive layer has insufficient cohesive force, and foaming phenomenon is easy to generate at high temperature; however, if the content of the bridging agent is too large, the hardness of the adhesive is excessively increased, and the adhesive cannot be tightly adhered to the contact surface, so that the adhesive force is reduced, and the Peeling between the films (Peeling) occurs.

The isocyanate-based crosslinking agent contains an isocyanate compound, wherein the isocyanate compound is a compound having an isocyanate group (-NCO), and the isocyanate compound has at least two isocyanate groups in a molecule, and is selected from the following groups: toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, hydrogenated xylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and the like. Further, the crosslinking agent may be obtained by using an adduct obtained by reacting the isocyanate compound with a polyhydric alcohol such as glycerin or trimethylolpropane, or by converting the isocyanate compound into a dimer or trimer.

The epoxy-based bridging agent may be selected from, for example: bisphenol a epoxy resins, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol triglycidyl ether, 1, 6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N-diglycidylaniline, N' -tetraglycidyl-m-xylylenediamine, 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane, and the like.

The imine-based bridging agent may be selected, for example, from: diethylenetriamine, triethylene tetramine, and the like. The metal chelate-based bridging agent may be selected from, for example: and compounds in which acetylacetone or ethyl acetoacetate is coordinated with a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, barium, chromium, and zirconium. The aziridine-based bridging agent may be selected, for example, from: diphenylmethane-4, 4' -bis (1-aziridinecarboxamide), toluene-2, 4-bis (1-aziridinecarboxamide), triethylenemelamine, isophthaloylbis-1- (2-methylaziridine), tris-1-aziridinyloxyphosphine oxide, hexamethylene-1, 6-bis (1-aziridinecarboxamide), trimethylolpropane-tri- β -aziridinylpropionate, tetramethylolmethane-tri- β -aziridinylpropionate, and the like.

[C] Silane coupling agent: in some embodiments, to improve the adhesion of the adhesive layer to other carrier films, silane coupling agents (optionally one or more of the following silane coupling agents) are added to promote the bonding of the organic polymer to the inorganic mineral surface, so that the composite material retains its strength (adhesion) over a long period of time. In some embodiments, the total amount of the silane coupling agent is 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, relative to 100 parts by weight of the base compound. The silane coupling agent may be selected, for example, from: silane compounds containing polymerizable unsaturated groups (e.g., ethylenic bonds) such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, and 3-methacryloxypropyltrimethoxysilane; or may be selected, for example, from: silane compounds having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylethoxydimethylsilane; or may be selected, for example, from: amino group-containing silane compounds such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane and N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane; or may be selected, for example, from: silane compounds containing a halogen substituent such as 3-chloropropylmethyldimethoxysilane and 3-chloropropyltrimethoxysilane; others are, for example: 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like.

The composition of the adhesive may also be added with other suitable additives, such as antistatic agents, viscosity modifiers, fillers (metal powder or other inorganic powder, etc.), oxidation inhibitors, dyes, pigments, defoaming agents, corrosion inhibitors, and the like, according to the actual product requirements.

In some embodiments, the adhesive can be applied to the surface of the carrier film by mixing the above components of the adhesive, allowing the mixture to stand for deaeration, and then applying the mixture to the surface of the carrier film by a method such as bar coating, blade coating, roll coating, sheet coating, die coating, gravure coating, or the like, and the dried adhesive forms an adhesive layer.

In some embodiments, the hydroxyl containing compound used to perform the adhesion promoting treatment comprises water, an alcohol, an acid, or a combination of the foregoing. Examples of the alcohol include methanol, ethanol, propanol, isopropanol, butanol, n-pentanol, and isopentanol. Examples of the acid include formic acid, acetic acid, propionic acid, butyric acid, n-valeric acid and isovaleric acid. In some embodiments, the hydroxyl-containing compound has a molecular weight of about 18 to 250, more preferably 18 to 150.

In some embodiments, the weight of the adhesive layer 103 on the first carrier film 101 increases by 0.8 to 4 wt% after passing through the adhesion-adjusting device 111 due to absorption of the provided hydroxyl-containing compound, compared to the weight of the adhesive layer 103 before passing through the adhesion-adjusting device 111.

In some embodiments, the adhesion force adjusting device 111 can be a humidifying device, and the compound that can provide hydroxyl groups to the adhesive layer 103 can include water, alcohol, acid, or a combination thereof. In some embodiments, where the compound of hydroxyl groups is water, the relative humidity (relative humidity) in the humidification device may be greater than 60%, and more preferably 75-95%. In some embodiments, the adhesive layer 103 has a water content of 0.8 to 4 wt% after passing through the humidifying device. If the relative humidity in the humidifying device is too low, it takes a long time to bring the adhesive layer 103 to a desired water content, or may even cause the adhesive layer 103 to fail to reach the desired water content. The water content in the scheme is measured by a dry weight method, and is specifically obtained according to the following formula:

water content (wt%) { (adhesive layer weight before drying treatment-adhesive layer weight after drying treatment)/adhesive layer weight before drying treatment } × 100%,

the drying treatment means that the adhesive layer is left at 120 ℃ for 2 hours.

In some embodiments, the humidifying device is not particularly limited as long as the device can supply water to the adhesive layer. For example, the humidifier may be a steam humidifier, a mist humidifier, a gasification humidifier or an ultrasonic humidifier.

The schematic manufacturing process shown in FIG. 1 can be implemented in a variety of ways. In some embodiments, the first carrier film 101 and the adhesive layer 103 thereon can be a non-carrier film (NCF) stripped release film, which is then bonded to a polarizing film or a polarizing plate. That is, the first carrier film 101 is a release film; and the second carrier film 102 is a polarizing film or a polarizing plate. The polarizing plate is a polarizing film with a protective film, for example, the polarizing plate may be a polarizing film with a first protective film thereon, or a polarizing film with a first protective film and a second protective film, and the polarizing film is disposed between the first protective film and the second protective film. The polarizing plate described hereinafter can be explained as such without further limitation.

In some embodiments, when the polarizing plate is a polarizing plate having a first protective film on only one side of the polarizing film, the first carrier film 101 may be attached to the protective film side of the polarizing plate as the second carrier film 102 or attached to the polarizing film side of the polarizing plate on the adhesive layer 103 side thereof. In some embodiments, when the polarizing plate is a polarizing film having a first protective film and a second protective film, and the polarizing film is disposed between the first protective film and the second protective film, the first carrier film 101 may be attached to the first protective film side of the polarizing plate or the second protective film side of the polarizing plate on the adhesive layer 103 side thereof. For example, referring to fig. 1 and 3, the first carrier film 101 is a release film 105 having an adhesive layer 103₁The second carrier film 102 has a polarizing film 107 disposed on the first protective film 108₁And a second protective film 108₂The laminated film 104 formed by laminating the polarizing plates 106 therebetween is shown in FIG. 3.

In other embodiments, the first carrier film 101 and the adhesive layer 103 thereon may be of a general commercially available substrate-free double-sided adhesive typeThe product in the state (Non-carrier film, NCF) was in the form of a release film with its one side peeled off, but was attached to a glass substrate. That is, referring to fig. 1 and 4, the first carrier film 101 is a release film 105 having an adhesive layer 103₁(ii) a The second carrier film 102 is a glass substrate 109, and the laminated film material 104 formed by bonding is shown in FIG. 4. The glass substrate may be, for example, a glass substrate in a liquid crystal display unit, thereby forming a liquid crystal display device. Examples of the material of the glass substrate include soda lime glass, low alkali glass, and alkali-free glass. The glass substrate described hereinafter can be explained without further limitation.

In other embodiments, a commonly available product with no-substrate double-sided tape (NCF) may be first attached to the polarizer after the release film on one side is removed. And then, after the release film on the other side is torn off, the glass substrate is bonded through the adhesive force adjusting device 111. That is, the first carrier film 101 is a polarizing plate and the second carrier film 102 is a glass substrate. For example, referring to fig. 1 and 5, the first carrier film 101 is a polarizing plate 106 having an adhesive layer 103, and in the polarizing plate 106, a polarizing film 107 is disposed on a first protective film 108₁And a second protective film 108₂Meanwhile, the second carrier film 102 is a glass substrate 109, and the laminated film material 104 formed by bonding the first carrier film 101 and the second carrier film 102 is shown in fig. 5.

Next, please refer to fig. 2. In other embodiments, the first carrier film 101 is dried before being tackified and then attached to the second carrier film 102. For example, before the first carrier film 101 passes through the adhesion adjusting device 111, the first carrier film 101 passes through the drying device 113, then passes through the adhesion adjusting device 111, and then is attached to the second carrier film 102 to form the laminated film material 104. By the drying treatment, the solvent content in the adhesive layer 103 on the first carrier film 101 can be further adjusted. In some embodiments, the solvent may be Methyl Ethyl Ketone (MEK), ethyl acetate (EAc), acetone (acetone), toluene (toluene), or the like. In some embodiments, the adhesive layer 103 has a residual amount of solvent of less than 30ppm (parts per million) after passing through the drying apparatus 113. The residual amount of the solvent can be detected by using a Hopkingawa detector tube (model AP-20).

The drying device 113 is not particularly limited as long as the solvent content in the adhesive agent layer 103 can be reduced. For example, the drying device 113 may be a heating device. By introducing the adhesive layer 103 into a heating device, the solvent in the adhesive layer is accelerated to be volatilized. In some embodiments, the heating device may be a heating furnace, such as a hot air oven, that increases the temperature in the furnace by providing hot air or having other heaters. The heater may be an infrared heater, a halogen heater, a flat heater, or the like. The heating device may be a heating roller having a heating medium such as warm water or other heater therein to raise the surface temperature. The drying conditions used by the drying device 113 are not particularly limited, and may be adjusted according to actual process requirements.

The method of FIG. 2 can be implemented in a variety of ways. In some embodiments, the first carrier film 101 and the adhesive layer 103 thereon can be a non-carrier film (NCF) type product, which is generally commercially available, and is peeled off from the release film, to form the laminated film material 104 shown in fig. 3 or fig. 4. In this embodiment, the solvent content of the adhesive layer in the NCF product can be further adjusted by the drying device 113. In some embodiments, instead of using a commercially available double-sided adhesive tape type product without a substrate, a release film is used as the first carrier film 101, and the adhesive layer 103 is formed by coating the prepared adhesive on the release film 101 before the release film passes through the drying device 113.

In some embodiments, the laminated film 104 shown in fig. 3 or fig. 5 can be formed by using the polarizing plate as the first carrier film 101 without the drying device excessively affecting the performance and properties of the polarizing plate. In these embodiments, the adhesive layer 103 can be formed by direct coating, or a common commercially available product with a Non-carrier film (NCF) type without a substrate can be peeled off, attached to the polarizer, and then the remaining release film on the other side is removed to expose the adhesive layer 103 for further processing.

In other embodiments, the manufacturing method shown in FIG. 2 can be used to manufacture non-carrier film (NCF) products. The first carrier film 101 may be a release film, and the prepared adhesive is coated on the release film before the first carrier film 101 passes through the drying device 113 to form the adhesive layer 103. Then, the release film and the adhesive layer 103 are passed through a drying device 113, the solvent content of the adhesive layer 103 is reduced to a desired range, for example, 30ppm or less after passing through the drying device 113, and the release film and the adhesive layer 103 passed through the drying device 113 and the adhesive force adjusting device 111 are bonded to another release film to form a double-sided adhesive type product without a substrate. At this time, the first carrier film 101 and the second carrier film 102 are release films. For example, referring to fig. 2 and 6, when the first carrier film 101 is the release film 105₁The second carrier film 102 is a release film 105₂The laminated film material 104 formed after the lamination is shown in fig. 6. In some embodiments, a first release film 105 for the first carrier film 101₁And a second release film 105 for a second carrier film₂Can be a release film having different peel forces to the adhesive layer 103. For example, the first release film 105₁Is a heavy release film; second release film 105₂Is a light release film. The light release film and the heavy release film herein respectively represent a release film having a relatively low peel force and a release film having a relatively high peel force.

The polarizing film described in this case is a film for converting light (polarized light having any direction) passing therethrough into polarized light having a specific direction. The polarizing film may be a known metal polarizing film, iodine polarizing film, dye polarizing film, polyethylene polarizing film, or the like. In one embodiment, the polarizing film is made of a polyvinyl alcohol (PVA) film containing dichroic pigments that can be adsorbed and aligned or formed by a liquid crystal material with absorption dye molecules. In one embodiment, the polarizer may be a polyvinyl alcohol (PVA) resin film, which may be prepared by saponifying a polyvinyl acetate resin. Examples of the polyvinyl acetate resin include a homopolymer of vinyl acetate, i.e., polyvinyl acetate, and a copolymer of vinyl acetate and other monomers copolymerizable with vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids (e.g., acrylic acid, methacrylic acid, ethyl acrylate, n-propyl 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., vinylsulfonic acid, sodium vinylsulfonate), and the like.

The method for forming the polarizing film layer is not particularly limited, and any suitable method known in the art may be used. Generally, the manufacturing method may include processes such as swelling treatment, film stretching treatment, dyeing treatment, crosslinking treatment, washing treatment, and drying treatment.

In some embodiments, the first protective film or the second protective film may have a single-layer or multi-layer structure, and is a thermoplastic resin with excellent transparency, mechanical strength, thermal stability, moisture barrier property, and the like. The thermoplastic resin may be a layer composed of a cellulose-based resin, which is a resin in which a part of hydroxyl groups in cellulose is esterified with acetic acid, or a mixed ester in which a part is esterified with acetic acid and a part is esterified with other acids. The cellulose-based resin is preferably a cellulose ester-based resin, more preferably an acetyl cellulose-based resin such as triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate and the like, and the cellulose which is sufficiently esterified is called triacetyl cellulose (TAC). Or other suitable materials such as acrylic resin film, polyaromatic hydroxyl resin film, polyether resin film, cyclic polyolefin resin film (e.g. polynorbornene resin film), polycarbonate resin such as polyester formed by carbonic acid and diol or bisphenol (e.g. polyethylene Terephthalate (PET)), polypropylene (PP), Polyethylene (PE), amorphous polyolefin resin such as cyclic olefin monomer (co) polymers (COC/COP), ring-opened polymer formed by norbornene, cyclopentadiene, dicyclopentadiene, tetracyclododecene, etc., or copolymer formed by olefin.

The protective film material may be used as a polarizing film protective film attached to one surface of a polarizing film to protect the polarizing film, or may be used as a temporary protective film (also referred to as a release film) after being subjected to a release treatment (e.g., a silicone treatment). The temporary protective film (release film) is a peelable protective film that is peeled off and removed in a desired period of time after the laminated film material is constructed.

The protective film may have a protective film for optical functions such as a retardation film and a brightness enhancement film. For example, the above-described properties can be imparted to a laminated film material by stretching a protective film made of the above-described material (uniaxial stretching, biaxial stretching, or the like), or laminating a surface treatment layer (coating layer) of another film layer such as a hard coat layer, an antiglare layer, a retardation film, an antireflection layer, a charge generation preventing layer, or an antifouling layer on the film. The layers may be a single layer or a multi-layer structure.

The release layer may be, for example, a polyethylene terephthalate film, or, for example, but not limited to, a silicone resin.

In some embodiments, the protective film may have a thickness of 1 to 100 μm, but from the viewpoint of handling property and the like, 5 to 60 μm is preferable, and 5 to 50 μm is more preferable. The thickness of the release film may be 1 to 100 μm, and more preferably 5 to 50 μm. The thickness of the adhesive layer may be 1 to 100. mu.m, and more preferably 5 to 50 μm.

In summary, the present invention provides a method for manufacturing a laminated film material, in which a hydroxyl group-containing compound is provided to an adhesive layer containing an isocyanate compound before different layers are attached to each other, so as to change the adhesive force of the adhesive layer, thereby obtaining a laminated film material having desired properties, such as better strength. And by the method, the existing process can be adjusted in the most economic way on the premise of not changing the formula of the adhesive used for directly coating the workpiece, so that the prepared product has the adhesive strength similar to that of the directly coated workpiece, and the overall manufacturing and management cost is reduced.

In addition, the present application also provides a laminated film material manufactured by the manufacturing method. The laminated film material has two film layers and an adhesive layer between the two film layers, and the adhesive layer has an isocyanate compound and a hydroxyl group-containing compound capable of reacting with the isocyanate compound. By containing a hydroxyl group-containing compound reactive with an isocyanate compound in the adhesive layer having an isocyanate compound, the adhesive force of the adhesive layer can be improved to obtain a laminated film having a desired strength.

In order to make the aforementioned and other objects, features and advantages of the present disclosure comprehensible, several embodiments accompanied with comparative examples are described in detail below, but not intended to limit the present disclosure.

[ preparation of test piece ]

After an adhesive containing an isocyanate compound (the concentration of the isocyanate compound was 0.5 wt%, and the thickness of the adhesive layer was 20 μm) was applied to a double release film (model SP-POGW #382051, lindecke) with a squeegee, the release film and the adhesive layer were passed through a heating furnace, and the solvent content in the adhesive layer was made to be less than 20ppm (detected using a hoechuan detector, model AP-20). Subsequently, the release film and the adhesive layer are sent to a humidifying device having a specific relative humidity to supply moisture to the adhesive layer. After the adhesive layer reaches a predetermined water content, the release film and the adhesive layer are separated from the humidifying device, and are bonded with a light release film (Lindelke, model SP-P #381130), and then the release film and the adhesive layer are kept standing for 7 days in an environment with the relative humidity of 23 ℃/65%.

After curing, the light release film is peeled off and the adhesive layer side is bonded to the polarizing plate. The polarizing plate has a structure of triacetylcellulose protective film/polyvinyl alcohol polarizing film/triacetylcellulose protective film in this order. After being bonded to a polarizing plate, the sheet was left standing for 1 day in an atmosphere of 23 ℃/RH 65%. The heavy release film is removed, and the polarizer is directly bonded to an alkali-free glass (Corning E-XG, width 25mm) via the adhesive layer. Then, the test piece was subjected to a pressure defoaming procedure at 50 ℃ under a pressure of 0.5MPa for 20 minutes. After standing still for 1 day in an environment of 23 ℃/65% relative humidity, an adhesion test was performed.

[ adhesion test ]

After the test piece was allowed to stand at 23 ℃ and 65% humidity for 24 hours, the adhesion of the test piece having a width of 25 cm was measured by a universal tensile machine (Shimadzu corporation), wherein the tensile speed was set to 300mm/min and the tensile angle was 180 degrees.

[ example 1]

The test piece of example 1 was prepared in the same manner as in the above [ test piece preparation ], wherein the relative humidity of the humidifier was set to 65. + -. 5%, and the water content of the adhesive layer after passing through the humidifier was 0.4 to 0.6 wt%. The adhesion of the test piece of example 1 was 1.82N by the adhesion test.

[ example 2]

The test piece of example 2 was prepared in the same manner as in the above [ test piece preparation ], wherein the relative humidity of the humidifier was set to 75. + -. 5%, and the water content of the adhesive layer after passing through the humidifier was 1.0 to 1.4 wt%. The adhesion of the test piece of example 2 was 2.13N by the adhesion test.

[ example 3]

The test piece of example 3 was prepared in the same manner as in the above [ test piece preparation ], wherein the relative humidity of the humidifier was set to 85. + -. 5%, and the water content of the adhesive layer after passing through the humidifier was 1.4 to 1.8 wt%. The adhesion of the test piece of example 3 was 3.42N by the adhesion test.

[ example 4]

The test piece of example 4 was prepared in the same manner as in the above [ test piece preparation ], wherein the relative humidity of the humidifier was set to 95%, and the water content of the adhesive layer after passing through the humidifier was 1.8 to 3 wt%. The adhesion of the test piece of example 4 was 3.89N by the adhesion test.

[ comparative example ]

In the comparative example, the test piece was prepared in the same manner as in the above [ test piece preparation ], and the adhesive layer contained the isocyanate compound at the same concentration, but the humidifying device was not turned on, and thus the relative humidity in the humidifying device was about 55% of the ambient relative humidity, and the water content in the adhesive layer after passing through the humidifying device was 0.4 to 0.6 wt%. The adhesion of the comparative test piece was 1.42N by the adhesion test.

The experimental conditions and the measured adhesion of each test piece are summarized in table 1 below.

TABLE 1

As can be seen from the adhesion test results summarized in table 1 above, as the relative humidity in the humidifying device increases, the upper limit of the water content in the adhesive layer by the humidifying device also increases. According to the experimental results, it can be seen that the adhesive force between the polarizer and the glass can be significantly improved by increasing the water content of the adhesive layer, and the laminated film formed by the adhesive with higher water content has better strength.

Although embodiments of the present disclosure and their advantages have been described above, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure by those skilled in the art. Moreover, the scope of the present disclosure is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. Accordingly, the scope of the present disclosure includes the processes, machines, manufacture, compositions of matter, means, methods, and steps described above. In addition, as can be appreciated by those skilled in the art from the foregoing description, the method for manufacturing a laminated film provided in the present disclosure can be applied to various embodiments. Each claim also constitutes a separate embodiment, and the scope of the present disclosure also includes combinations of each claim and embodiment. The scope of the present disclosure should be determined with reference to the appended claims.

Claims

1. A method for manufacturing a laminated film material includes:

(a) providing a first carrier film, wherein the first carrier film is provided with an adhesive layer, and the adhesive layer contains an isocyanate compound;

(b) subjecting the first carrier film to a tackifying treatment for providing a tackifier, which contains a hydroxyl compound, to the entire adhesive layer; and

(c) attaching the first carrier film subjected to the tackification treatment to a second carrier film at the adhesive side to form the laminated film material,

wherein the tackifying treatment is to make the first carrier film pass through an adhesive force adjusting device, the adhesive force adjusting device is a humidifying device, and the humidifying device provides the tackifier for the adhesive agent layer.

2. The method of claim 1, wherein the hydroxyl containing compound comprises water, an alcohol, an acid, or a combination of the foregoing, or the hydroxyl containing compound has a molecular weight of 18-250.

3. The method of claim 1, wherein the weight of the adhesive layer subjected to the adhesion-promoting treatment is increased by 0.8 to 4 wt% compared to the weight of the adhesive layer before the adhesion-promoting treatment.

4. The method of claim 1, wherein the laminated film is produced by a method comprising

The first carrier film comprises a release film; and

the second carrier film includes a polarizing plate including a first protective film and a polarizing film on the first protective film.

5. The method of claim 1, wherein the first carrier film comprises a polarizing plate comprising a first protective film and a polarizing film on the first protective film, and the second carrier film comprises a glass substrate; or the first carrier film comprises a first release film and the second carrier film comprises a second release film.

6. The method of manufacturing a multilayer film according to claim 1, wherein the relative humidity in the humidifying device is 60% or more.

7. The method of claim 1, wherein the moisture content of the adhesive layer after passing through the humidifying device is 0.8 wt% to 3 wt%.

8. The method of claim 1, wherein the humidifier is a vapor humidifier, a mist humidifier, or an ultrasonic humidifier.

9. The method of claim 1, further comprising passing the first carrier film through a drying device before passing the first carrier film through the adhesion adjusting device.

10. The method of claim 9, wherein the drying device comprises a heating furnace or a heating roller.

11. The method of producing a laminated film according to claim 9, wherein the adhesive layer has a residual solvent content of less than 30ppm after passing through the drying device.

12. A laminated film comprising:

a first carrier film;

a second carrier film; and

and an adhesive layer between the first carrier film and the second carrier film, the adhesive layer containing an isocyanate compound and a hydroxyl group-containing compound reactive with the isocyanate compound, the adhesive layer having a water content of 1.4 wt% to 3 wt%, and an adhesive force of 3.42 to 3.89N/25 mm.

13. The laminate film of claim 12, wherein the hydroxyl containing compound comprises water, an alcohol, an acid, or a combination of the foregoing, or the hydroxyl containing compound has a molecular weight of 18-250.

14. The laminate film of claim 12, wherein

The first carrier film comprises a release film;

15. The laminated film as claimed in claim 14, wherein the polarizer further comprises a second protective film disposed between the release film and the first protective film, and the polarizing film is disposed between the first protective film and the second protective film.

16. The laminate film of claim 12, wherein

The first carrier film comprises a polarizing plate, and the polarizing plate comprises a first protective film and a polarizing film on the first protective film; and

the second carrier film comprises a glass substrate.

17. The laminate film of claim 12, wherein the first carrier film comprises a first release film; and the second carrier film comprises a second release film.

18. The laminate film of claim 17, wherein the first release film and the second release film have different peel forces with respect to the adhesive layer.

19. The laminate film of claim 12, wherein the adhesive layer has a residual solvent content of less than 30 ppm.