阅读说明：本技术 耐擦伤性硬涂膜的制造方法 (Method for producing scratch-resistant hard coating film ) 是由 原口将幸 辻本晴希 于 2019-06-25 设计创作，主要内容包括：本发明的课题是提供具有优异的耐擦伤性的硬涂膜的制造方法。解决手段是一种耐擦伤性硬涂膜的制造方法,其至少包含下述工序：将能够形成硬涂层的固化性组合物涂布在膜基材上而形成涂膜的工序；以及向该涂膜照射活性能量射线进行固化的工序,上述固化性组合物所包含的溶剂为在其标准沸点下的上述膜基材的溶剂溶胀度为70％以下的溶剂。(The present invention addresses the problem of providing a method for producing a hard coating film having excellent scratch resistance. The solution is a method for producing a scratch-resistant hard coating film, which comprises at least the following steps: a step of applying a curable composition capable of forming a hard coat layer on a film substrate to form a coating film; and a step of irradiating the coating film with an active energy ray to cure the coating film, wherein the solvent contained in the curable composition is a solvent having a solvent swelling degree of the film base material at its normal boiling point of 70% or less.)

1. A method for producing a scratch-resistant hard coating film, comprising at least the following steps:

a step of applying a curable composition capable of forming a hard coat layer on a film substrate to form a coating film; and

a step of irradiating the coating film with an active energy ray to cure the coating film,

the curable composition contains a solvent having a solvent swelling degree of 70% or less of the film substrate at its normal boiling point.

2. The production method according to claim 1, the film substrate being a thermoplastic polyurethane film.

3. The production method according to claim 1 or 2, wherein the curable composition comprises:

(a) 100 parts by mass of an oxyalkylene-modified polyfunctional monomer having at least 3 active energy ray-polymerizable groups;

(b) 0.1 to 10 parts by mass of a perfluoropolyether in which both ends of a molecular chain of a poly (oxyperfluoroalkylene) group are organically modified with or without the poly (oxyperfluoroalkylene) group; and

(c) 1 to 20 parts by mass of a polymerization initiator that generates radicals by active energy rays.

4. The production process according to claim 3, wherein the perfluoropolyether (b) in which both ends of a molecular chain of a poly (oxyperfluoroalkylene) group are organically modified with or without a poly (oxyperfluoroalkylene) group is a perfluoropolyether selected from the group consisting of the following (b1) to (b6),

(b1) perfluoropolyethers alcohol-modified, piperonyl-modified, carboxylic acid-modified, or ester-modified at both ends of the molecular chain containing a poly (oxyperfluoroalkylene) group with or without a poly (oxyperfluoroalkylene) group, (b2) perfluoropolyethers having alkoxysilyl groups bonded to both ends of the molecular chain containing a poly (oxyperfluoroalkylene) group via a poly (oxyalkylene) group and further via a divalent linking group,

(b3) perfluoropolyethers having alkoxysilyl groups bonded to both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group via a linking structure not having a poly (oxyalkylene) structure,

(b4) a perfluoropolyether having an active energy ray-polymerizable group via a poly (oxyalkylene) group at one end of a molecular chain containing a poly (oxyperfluoroalkylene) group and a hydroxyl group via a poly (oxyalkylene) group at the other end of the molecular chain,

(b5) a perfluoropolyether having an active energy ray-polymerizable group via a poly (oxyalkylene) group or via a poly (oxyalkylene) group and 1 urethane bond in this order at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group,

(b6) a perfluoropolyether having an active energy ray-polymerizable group via a urethane bond at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group, wherein the perfluoropolyether having a poly (oxyalkylene) group between the poly (oxyperfluoroalkylene) group and the urethane bond is excluded.

5. The production process according to claim 4, wherein the perfluoropolyether (b) in which both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group are organically modified with or without a poly (oxyperfluoroalkylene) group is (b6) a perfluoropolyether having an active energy ray-polymerizable group via a urethane bond at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group, excluding a perfluoropolyether having a poly (oxyperfluoroalkylene) group between the poly (oxyperfluoroalkylene) group and the urethane bond.

6. The method according to any one of claims 1 to 5, wherein the solvent contained in the curable composition is 1 or 2 or more alcohols selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 2-ethylhexyl alcohol, benzyl alcohol, and ethylene glycol.

7. The method according to claim 6, wherein the solvent contained in the curable composition is methanol.

Technical Field

The present invention relates to a method for producing a hard coating film having scratch resistance, and more particularly, to a method for producing a hard coating film having excellent scratch resistance.

Background

A touch panel display using a liquid crystal display element or an OLED (organic EL) display element that can be operated with a finger is provided in a large number of electronic devices such as home electric appliances such as televisions, communication devices such as mobile phones, business devices such as copying machines, entertainment devices such as game machines, medical devices such as X-ray imaging devices, and living devices such as microwave ovens. In these touch panel displays, in order to prevent scratches from being generated on the surface of the touch panel by fingernails and the like when operated with fingers, a hard coat film having scratch resistance is provided on the outermost surface of the touch panel, and the hard coat film is provided on a transparent plastic film as a base material.

On the other hand, in recent years, in order to improve the design of the electronic device as described above, a design in which the touch panel display portion is curved is sometimes adopted. When the touch panel is bent with the touch panel side being the outer side, stress in the tensile direction is generated in the hard coat layer on the outermost surface. Therefore, a certain stretchability is required for the hard coat layer.

As a general method for forming a hard coat layer, a hard coat layer is obtained by applying a hard coat layer liquid containing a polyfunctional acrylate as a main agent, a photopolymerization initiator for causing the polyfunctional acrylate to undergo a curing reaction by radical polymerization using active energy rays, and an organic solvent for diluting the polyfunctional acrylate and imparting coatability to the base material, removing the organic solvent by heating and drying, and then curing by irradiation with active energy rays. However, a material containing a multifunctional acrylate as a main agent has low molecular mobility due to its high crosslinking density, and has resistance to external force, and therefore, although scratch resistance is obtained, it generally has no stretchability.

Therefore, in order to impart a certain scratch resistance and stretchability to the hard coat layer, for example, a method of using a polyfunctional acrylate oligomer or a polyfunctional urethane acrylate oligomer having a molecular weight of about 1,000 to 10,000 and having an adjusted acrylate group density is employed. These multifunctional acrylate oligomers have a crosslinking site and a stretching site in the molecular structure, and can exhibit appropriate scratch resistance and stretchability due to molecular mobility of the stretching site. A hard coat layer using a polycaprolactone-modified multifunctional acrylate as such a multifunctional acrylate oligomer is disclosed (patent document 1).

Further, as a method for imparting antifouling property and sliding property to the surface of the hard coat layer, a method of adding a fluorine-based surface modifier in a small amount to a coating liquid for forming the hard coat layer is used. The added fluorine-based surface modifier segregates on the surface of the hard coat layer due to its low surface energy, and imparts water repellency and oil repellency. The fluorine-based surface modifier is an oligomer called perfluoropolyether having a poly (oxyperfluoroalkylene) chain, having an active energy ray-curable moiety and having a number average molecular weight of about 1,000 to 5,000, from the viewpoint of water repellency and oil repellency. However, since these perfluoropolyethers have a high fluorine concentration, the solubility in organic solvents is specific, and only limited organic solvents can be used.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2013/191254

Disclosure of Invention

Problems to be solved by the invention

The present invention addresses the problem of providing a method for producing a hard coating film having excellent scratch resistance.

Means for solving the problems

As a result of intensive studies to solve the above problems, the present inventors have found that, in a method for producing a scratch-resistant hard coating film comprising at least a step of forming a coating film by applying a curable composition capable of forming a hard coating layer on a film substrate and a step of irradiating the coating film with active energy rays for curing, a hard coating film having excellent scratch resistance can be produced if a solvent having a solvent swelling degree of the film substrate at its normal boiling point of 70% or less is selected as a solvent contained in the curable composition, and have completed the present invention.

Further, the present inventors have also found that a hard coat film having stretchability in addition to excellent scratch resistance can be produced by using an appropriate film base material.

That is, the present invention relates to, as a first aspect, a method for producing a scratch-resistant hard coat film, comprising at least the steps of: a step of applying a curable composition capable of forming a hard coat layer on a film substrate to form a coating film; and a step of irradiating the coating film with an active energy ray to cure the coating film, wherein the solvent contained in the curable composition is a solvent having a solvent swelling degree of the film base material at its normal boiling point of 70% or less.

An aspect 2 relates to the production method according to aspect 1, wherein the film base is a thermoplastic polyurethane film.

The 3 rd aspect relates to the production method according to the 1 st or 2 nd aspect, wherein the curable composition comprises:

(a) 100 parts by mass of an oxyalkylene-modified polyfunctional monomer having at least 3 active energy ray-polymerizable groups;

(b) 0.1 to 10 parts by mass of a perfluoropolyether in which both ends of a molecular chain of a poly (oxyperfluoroalkylene) group are organically modified with or without the poly (oxyperfluoroalkylene) group; and

(c) 1 to 20 parts by mass of a polymerization initiator that generates radicals by active energy rays.

In view of 4, the process according to view of 3, wherein the perfluoropolyether (b) in which both ends of the molecular chain of the poly (oxyperfluoroalkylene) group are organically modified with or without the poly (oxyperfluoroalkylene) group is a perfluoropolyether selected from the following (b1) to (b 6).

(b1) Perfluoropolyethers having alcohol-modified, piperonyl-modified, carboxylic acid-modified or ester-modified both ends of the molecular chain containing a poly (oxyperfluoroalkylene) group with or without a poly (oxyalkylene) group,

(b2) perfluoropolyethers having alkoxysilyl groups bonded to both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group via a poly (oxyalkylene) group and further via a divalent linking group,

(b3) perfluoropolyethers having alkoxysilyl groups bonded to both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group via a linking structure not having a poly (oxyalkylene) structure,

(b4) a perfluoropolyether having an active energy ray-polymerizable group via a poly (oxyalkylene) group at one end of a molecular chain containing a poly (oxyperfluoroalkylene) group and a hydroxyl group via a poly (oxyalkylene) group at the other end of the molecular chain,

(b5) a perfluoropolyether having an active energy ray-polymerizable group via a poly (oxyalkylene) group or via a poly (oxyalkylene) group and 1 urethane bond in this order at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group,

(b6) perfluoropolyether having active energy ray-polymerizable groups via urethane bonds at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group (with the exception of perfluoropolyether having a poly (oxyalkylene) group between the poly (oxyperfluoroalkylene) group and the urethane bond)

As a5 th aspect, the present invention relates to the production method according to the 4 th aspect, wherein the perfluoropolyether (b) in which both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group are organically modified with or without a poly (oxyalkylene) group is the perfluoropolyether (b6) having an active energy ray-polymerizable group through a urethane bond at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group (excluding the perfluoropolyether having a poly (oxyalkylene) group between the poly (oxyperfluoroalkylene) group and the urethane bond).

A 6 th aspect relates to the production method according to any one of the 1 st to 5 th aspects, wherein the solvent contained in the curable composition is 1 or 2 or more alcohols selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, 2-ethylhexyl alcohol, benzyl alcohol, and ethylene glycol.

In a 7 th aspect, the present invention relates to the production method according to the 6 th aspect, wherein the solvent contained in the curable composition is methanol.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a method for producing a hard coating film having excellent scratch resistance can be provided.

Further, by using an appropriate film base material, a method for producing a hard coat film having stretchability in addition to excellent scratch resistance can be provided.

Detailed Description

The present invention relates to a method for producing a scratch-resistant hard coating film, which comprises at least the following steps: a step of applying a curable composition capable of forming a hard coat layer on a film substrate to form a coating film; and a step of irradiating the coating film with an active energy ray to cure the coating film, wherein the solvent contained in the curable composition is a solvent having a solvent swelling degree of the film base material at its normal boiling point of 70% or less.

The method for producing the scratch-resistant hard coat film of the present invention will be described in detail below.

< curable composition >

The curable composition capable of forming a hard coat layer that can be used in the present invention is not particularly limited as long as it is a composition capable of forming a hard coat layer by curing by irradiation with an active energy ray, and conventionally known ones can be used. Preferred examples of the curable composition include:

(a) 100 parts by mass of an oxyalkylene-modified polyfunctional monomer having at least 3 active energy ray-polymerizable groups;

(b) 0.1 to 10 parts by mass of a perfluoropolyether in which both ends of a molecular chain of a poly (oxyperfluoroalkylene) group are organically modified with or without the poly (oxyperfluoroalkylene) group; and

(c) 1 to 20 parts by mass of a polymerization initiator that generates radicals by active energy rays.

The respective components (a) to (c) will be described below.

[ (a) an oxyalkylene-modified polyfunctional monomer having at least 3 active energy ray-polymerizable groups ]

The oxyalkylene-modified polyfunctional monomer having at least 3 active energy ray-polymerizable groups means a polyfunctional monomer modified with an oxyalkylene group having at least 3 active energy ray-polymerizable groups.

The oxyalkylene-modified polyfunctional monomer (a) having at least 3 active energy ray-polymerizable groups which is preferable in the curable composition of the present invention is a monomer selected from the group consisting of an oxyalkylene-modified polyfunctional (meth) acrylate compound and an oxyalkylene-modified polyfunctional urethane (meth) acrylate compound having at least 3 active energy ray-polymerizable groups.

In the present invention, the (meth) acrylate compound means both an acrylate compound and a methacrylate compound. For example, (meth) acrylic acid refers to acrylic acid and methacrylic acid.

Examples of the oxyalkylene group in the oxyalkylene group-modified polyfunctional monomer (a) having at least 3 active energy ray-polymerizable groups include an oxyethylene group and an oxy (methylethylene) group, and examples of a preferable oxyalkylene group-modified polyfunctional monomer include an oxyethylene (oxyvinylene) modified polyfunctional monomer.

Examples of the oxyalkylene-modified polyfunctional (meth) acrylate compound include (meth) acrylate compounds of polyhydric alcohols modified with oxyethylene groups or oxy groups (methylethylene groups).

Examples of the polyhydric alcohol include glycerin, diglycerin, triglycerin, tetraglycerin, pentaglycerin, hexaglycerin, decaglycerin, polyglycerin, trimethylolpropane, ditrimethylolpropane, pentaerythritol, and dipentaerythritol.

Examples of the active energy ray-polymerizable group in the oxyalkylene-modified polyfunctional monomer (a) having at least 3 active energy ray-polymerizable groups include a (meth) acryloyloxy group, a vinyl group and an epoxy group.

The number of addition of oxyalkylene groups such as oxyethylene groups and oxy (methylethylene) groups is 1 to 30, preferably 1 to 12, to the molecule of the oxyalkylene-modified polyfunctional monomer (a) 1 having at least 3 active energy ray-polymerizable groups.

In the present invention, the oxyalkylene modified polyfunctional monomer (a) having at least 3 active energy ray-polymerizable groups may be used singly or in combination of two or more.

Preferable examples of the oxyalkylene-modified polyfunctional monomer (a) having at least 3 active energy ray-polymerizable groups include (a1) an oxyethylene-modified polyfunctional monomer having at least 3 active energy ray-polymerizable groups, and an oxyethylene-modified polyfunctional monomer having an average oxyethylene modification amount of less than 3mol per 1mol of the polymerizable groups (also referred to simply as (a1) an oxyethylene-modified polyfunctional monomer having at least 3 active energy ray-polymerizable groups).

Preferred examples of (a1) the oxyethylene modified polyfunctional monomer having at least 3 active energy ray-polymerizable groups in the curable composition capable of forming a hard coat layer include monomers selected from the group consisting of an oxyethylene modified polyfunctional (meth) acrylate compound and an oxyethylene modified polyfunctional urethane (meth) acrylate compound having at least 3 active energy ray-polymerizable groups and an average oxyethylene modification amount of less than 3mol per 1mol of the polymerizable groups.

(a1) The average oxyethylene modification amount in the oxyethylene-modified polyfunctional monomer having at least 3 active energy ray-polymerizable groups is less than 3mol based on 1mol of the active energy ray-polymerizable group contained in the monomer, and preferably less than 2mol based on 1mol of the active energy ray-polymerizable group contained in the monomer.

The average oxyethylene modification amount in the (a) oxyethylene-modified polyfunctional monomer having at least 3 active energy ray-polymerizable groups is more than 0mol per 1mol of the active energy ray-polymerizable group contained in the monomer, preferably 0.1mol or more per 1mol of the active energy ray-polymerizable group contained in the monomer, and more preferably 0.5mol or more.

Examples of the oxyethylene-modified polyfunctional (meth) acrylate compound include, for example, an oxyethylene-modified (meth) acrylate compound of a polyol.

The number of addition of oxyethylene groups is 1 to 30, preferably 1 to 12, to 1 molecule of the oxyethylene-modified polyfunctional monomer 1 having at least 3 active energy ray-polymerizable groups (a 1).

[ (b) perfluoropolyether in which both ends of the molecular chain containing a poly (oxyperfluoroalkylene) group are modified with an organic group with or without the poly (oxyperfluoroalkylene) group ]

(b) The component (a) functions as a surface modifier in a hard coat layer to which the curable composition of the present invention is applied. Further, the component (b) has excellent compatibility with the component (a), and thus, the hard coat layer can be suppressed from clouding and can be formed to have a transparent appearance.

Preferable examples of the organic group in the component (b) include an alcohol (hydroxyl group), a piperonyl group, a carboxylic acid (carboxyl group), an ester (alkoxycarbonyl group, acyloxy group), an alkoxysilyl group, and an active energy ray-polymerizable group.

The preferable (b) perfluoropolyether having both ends of the molecular chain of the poly (oxyperfluoroalkylene) group organically modified with or without the poly (oxyalkylene) group can be selected from, for example, the following (b1) to (b6) (hereinafter, also referred to as perfluoropolyethers (b1) to (b 6)).

(b1) Perfluoropolyether (b2) in which both ends of the molecular chain containing a poly (oxyperfluoroalkylene) group are alcohol-modified, piperonyl-modified, carboxylic acid-modified, or ester-modified with or without a poly (oxyperfluoroalkylene) group, perfluoropolyether in which alkoxysilyl groups are bonded to both ends of the molecular chain containing a poly (oxyperfluoroalkylene) group via a poly (oxyalkylene) group and further via a divalent linking group, respectively

(b3) Perfluoropolyether having alkoxysilyl groups bonded to both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group via a linking structure not having a poly (oxyalkylene) structure

(b4) Perfluoropolyether having an active energy ray-polymerizable group via a poly (oxyalkylene) group at one end of a molecular chain containing a poly (oxyperfluoroalkylene) group and a hydroxyl group via a poly (oxyalkylene) group at the other end of the molecular chain

(b5) Perfluoropolyether having active energy ray-polymerizable group via poly (oxyalkylene) group or poly (oxyalkylene) group and 1 urethane bond in this order at both ends of molecular chain containing poly (oxyperfluoroalkylene) group

(b6) Perfluoropolyether having active energy ray-polymerizable groups via urethane bonds at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group (with the exception of perfluoropolyether having a poly (oxyalkylene) group between the poly (oxyperfluoroalkylene) group and the urethane bond)

The number of carbon atoms of the alkylene group in the poly (oxyperfluoroalkylene) group that can be used in the perfluoropolyethers (b1) to (b6) is not particularly limited, but is preferably 1 to 4 carbon atoms. That is, the poly (oxyperfluoroalkylene) group is a group having a structure in which a 2-valent carbon fluoride group having 1 to 4 carbon atoms and an oxygen atom are alternately bonded to each other, and the oxyperfluoroalkylene group is a group having a structure in which a 2-valent carbon fluoride group having 1 to 4 carbon atoms and an oxygen atom are bonded to each other. Specifically, it includes- [ OCF ]₂]- (oxyperfluoromethylene), - [ OCF₂CF₂]- (oxyperfluoroethylene), - [ OCF₂CF₂CF₂]- (oxyperfluoropropane-1, 3-diyl), [ OCF₂C(CF₃)F]- (oxyperfluoropropane-1, 2-diyl) and the like.

One kind of the oxyperfluoroalkylene group may be used alone, or two or more kinds may be used in combination, and in this case, the combination of plural kinds of oxyperfluoroalkylene groups may be either of block combination and random combination.

Among them, it is preferable to use a poly (oxyperfluoroalkylene) group having- [ OCF ] as a group from the viewpoint of obtaining a cured film having good scratch resistance₂]- (oxyperfluoromethylene) and- [ OCF₂CF₂]Both- (oxyperfluoroethylene) as the radical of the repeating unit.

Among them, as the poly (oxyperfluoroalkylene) group, preferred are repeating units: - [ OCF₂]And- [ OCF₂CF₂]-in molar ratio to become [ repeating unit: - [ OCF₂]-]: [ repeating unit: - [ OCF₂CF₂]-]2: 1-1: 2, more preferably so as to be in the range of about 1: 1, respectively. The combination of these repeating units may be either block combination or random combination.

The total number of repeating units of the oxyperfluoroalkylene group is preferably 5 to 30, more preferably 7 to 21.

The poly (oxyperfluoroalkylene) group has a weight average molecular weight (Mw) of 1,000 to 5,000, preferably 1,500 to 3,000, or 1,500 to 2,000, as measured in terms of polystyrene by Gel Permeation Chromatography (GPC).

The number of carbon atoms of the alkylene group in the poly (oxyalkylene) group that can be used for the perfluoropolyether (b1), (b2), (b4), and (b5) is not particularly limited, but is preferably 1 to 4 carbon atoms. That is, the poly (oxyalkylene) group is a group having a structure in which alkylene groups having 1 to 4 carbon atoms are alternately bonded to oxygen atoms, and the oxyalkylene group is a group having a structure in which 2-valent alkylene groups having 1 to 4 carbon atoms are bonded to oxygen atoms. Examples of the alkylene group include an ethylene group, a 1-methylethylene group, a1, 3-propylene group, and a1, 4-butylene group.

The oxyalkylene group may be used singly or in combination of two or more, and in this case, the combination of plural kinds of oxyalkylene groups may be either block combination or random combination.

Among them, the poly (oxyalkylene) group is preferably a poly (oxyethylene) group.

The number of repeating oxyalkylene units in the poly (oxyalkylene) group is, for example, in the range of 1 to 15, more preferably, in the range of, for example, 5 to 12, and, for example, 7 to 12.

Examples of the active energy ray-polymerizable group that can be used in the perfluoropolyethers (b4) to (b6) include, for example, a (meth) acryloyl group, a urethane (meth) acryloyl group, and a vinyl group, but the active energy ray-polymerizable group is not limited to having an active energy ray-polymerizable moiety such as 1 (meth) acryloyl moiety, and may have 2 or more active energy ray-polymerizable moieties.

In the present invention, it is desirable that (b) perfluoropolyether, both ends of the molecular chain of which are organically modified with or without a poly (oxyperfluoroalkylene) group, is used in a proportion of 0.1 to 10 parts by mass, preferably 0.2 to 5 parts by mass, relative to 100 parts by mass of the component (a).

Hereinafter, the perfluoropolyethers (b1) to (b6) are described in more detail.

[ (b1) perfluoropolyether alcohol-modified, pepper-modified, carboxylic acid-modified or ester-modified with or without poly (oxyperfluoroalkylene) group at both ends of molecular chain containing poly (oxyperfluoroalkylene) group ]

The perfluoropolyether (b1) having been alcohol-modified, piperonyl-modified, carboxylic acid-modified, or ester-modified is, among the perfluoropolyethers, alcohol-modified perfluoropolyethers having both ends, piperonyl-modified perfluoropolyethers having both ends, carboxylic acid-modified perfluoropolyethers having both ends, or ester-modified perfluoropolyethers having both ends.

Specific examples of the perfluoropolyether (b1) include the following.

Both terminal alcohol modifications: FOMBLIN (registered trademark) ZDOL 2000, FOMBLIN ZDOL 2500, FOMBLIN ZDOL 4000, FOMBLIN TX, FOMBLIN ZTEROL 2000GT, FLUOROLINK (registered trademark) D10H, and FLUOROLINK E10H [ all ソルベイスペシャルティポリマーズ Co. ];

modification of the two terminal piperonyl groups: FOMBLIN (registered trademark) AM2001 and FOMBLIN AM3001[ both manufactured by ソルベイスペシャルティポリマーズ;

both terminal carboxylic acid modifications: FLUOROLINK (registered trademark) C10 (manufactured by ソルベイスペシャルティポリマーズ Co.);

two-terminal ester modification: FLUOROLINK (registered trademark) L10H (manufactured by ソルベイスペシャルティポリマーズ Co.);

[ (b2) perfluoropolyether having alkoxysilyl groups bonded to both ends of the molecular chain containing a poly (oxyperfluoroalkylene) group via a poly (oxyalkylene) group and further via a divalent linking group ]

The alkoxysilyl group in the perfluoropolyether (b2) is preferably a group represented by the following formula [1 ].

-Si(OR¹)_aR² _3-a [1]

In the above formula [1]In, R¹Represents an alkyl group having 1 to 5 carbon atoms, R²Represents an alkyl group having 1 to 5 carbon atoms or a phenyl group, and a represents an integer of 1 to 3.

Examples of the divalent linking group include divalent groups such as alkylene groups having 1 to 5 carbon atoms, oxygen atoms, ester bonds, amide bonds, urethane bonds, urea bonds, and combinations thereof.

The perfluoropolyether (b2) is preferably a compound represented by the following formula [2 ].

(R¹O)_aSi(R² _3-a)-L¹-X¹-(L³O)_m-PEPE1-(OL⁴)_n-X²-L²-Si(OR³)_bR⁴ _3-b [2]

In the above formula [2]In, R¹And R³Each independently represents an alkyl group having 1 to 5 carbon atoms, R²And R⁴Each independently represents an alkyl group having 1 to 5 carbon atoms or a phenyl group, a and b each independently represents an integer of 1 to 3, L¹～L⁴Each independently represents an alkylene group having 1 to 5 carbon atoms, X¹And X²Each independent earth surfaceThe formula represents-OC- (O) -, -OC- (O) NH-, -NHC- (O) -, -NHC- (O) NH-or-O-, m and n each represents a positive integer where m + n is 2 to 40, and PFPE1 represents a group having a poly (oxyperfluoroalkylene) structure as a core and a terminal structure connected to an oxyalkylene group on both sides thereof.

As the above-mentioned R¹And R³Specific examples of the alkyl group having 1 to 5 carbon atoms in (A) include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a sec-pentyl group, a 3-pentyl group and a cyclopentyl group.

In these specific examples, R is¹And R³Preferably methyl or ethyl.

As the above-mentioned R²And R⁴Specific examples of the alkyl group having 1 to 5 carbon atoms in (A) include the above-mentioned R¹And R³The groups exemplified.

As R²And R⁴Preferably methyl or phenyl.

The above a and b are preferably 3.

Furthermore as L¹～L⁴Specific examples of the alkylene group having 1 to 5 carbon atoms in (A) include methylene, ethylene, 1, 3-propylene, methylethylene, 1, 4-butylene, 1-methyl-1, 3-propylene, 2-methyl-1, 3-propylene, 1-dimethylethylene, 1, 5-pentylene, 1-methyl-1, 4-butylene, 2-methyl-1, 4-butylene, 1-dimethyl-1, 3-propylene, 1, 2-dimethyl-1, 3-propylene, 2-dimethyl-1, 3-propylene, and 1-ethyl-1, 3-propylene.

In these specific examples, L is¹And L²Preferably an ethylene group or a1, 3-propylene group, more preferably a1, 3-propylene group.

Furthermore as L³And L⁴Preferably, ethylene or methylethylene is used, and more preferably, ethylene is used. I.e. as (L)₃O) Or (OL)₄) The oxyalkylene group represented by (A) is preferably an oxyethylene group.

X is above¹And X²Preferably, it is — OC (═ O) -or — OC (═ O) NH-, more preferably — OC (═ O) NH-, and still more preferably — OC (═ O) NH —Is selected from the group consisting of O-OC (O) NH- (wherein R represents and (L)³O)_mOr (OL)⁴)_nThe bonding end of).

M and n are each preferably a positive integer of 12 to 20 in terms of m + n.

PFPE1 represents a group having a poly (oxyperfluoroalkylene) structure as a core and having terminal structures bonded to the oxyalkylene group on both sides thereof.

The poly (oxyperfluoroalkylene) structure may include those specifically mentioned in the above-mentioned poly (oxyperfluoroalkylene) group as a suitable structure.

Examples of the terminal structure to which oxyalkylene groups are bonded on both sides thereof include, in the case where the terminal structure is bonded to the-O-terminal of a poly (oxyperfluoroalkylene) group, a C2 or C3 alkylene group substituted with 1 to 3 fluorine atoms, or a O-CF group₂C (═ O) -, at the fluoroalkylene end of the poly (oxyperfluoroalkylene) group (e.g., -CF)₂-、-C(CF₃) Examples of the linkage of F-) include O- (alkylene group having 2 or 3 carbon atoms substituted with 1 to 3 fluorine atoms) -, O-CF₂C (═ O) - (. O.) denotes the binding end to the poly (oxyperfluoroalkylene) group.

Examples of the alkylene group having 2 or 3 carbon atoms substituted with 1 to 3 fluorine atoms include, for example, -CHFCH₂-、-CF₂CH₂-、-CF₂CHF-、-CHFCH₂CH₂-、-CF₂CH₂CH₂-、-CF₂CHFCH₂-, preferably-CF₂CH₂-。

In the curable composition capable of forming a hard coat layer, perfluoropolyether (b2) may be used alone or in combination of two or more.

The perfluoropolyether (b2) is obtained, for example, by a method in which, in a compound having hydroxyl groups at both ends of a molecular chain containing poly (oxyperfluoroalkylene) groups via poly (oxyalkylene) groups, an alkoxysilane having an isocyanate group such as (3-isocyanatopropyl) trimethoxysilane is reacted with the hydroxyl groups at both ends thereof.

[ (b3) perfluoropolyether having alkoxysilyl groups bonded to both ends of the molecular chain containing a poly (oxyperfluoroalkylene) group via a linking structure not having a poly (oxyperfluoroalkylene) structure ]

The poly (oxyperfluoroalkylene) group and the alkoxysilyl group are exemplified by those exemplified for the perfluoropolyether (b 2). Further, examples of the linking structure having no poly (oxyalkylene) structure include those listed as the "divalent linking group" in the above perfluoropolyether (b 2).

The perfluoropolyether (b3) is preferably a compound represented by the following formula [3 ].

(R⁵O)_rSi(R⁶ _3-r)-L⁵-X³-PFPE2-X⁴-L⁶-Si(OR⁷)_sR⁸ _3-s [3]

In the above formula [3]In, R⁵And R⁷Each independently represents an alkyl group having 1 to 5 carbon atoms, R⁶And R⁸Each independently represents an alkyl group having 1 to 5 carbon atoms or a phenyl group, r and s each independently represents an integer of 1 to 3, L⁵And L⁶Each independently represents an alkylene group having 1 to 5 carbon atoms, X³And X⁴Each independently represents-OC (═ O) -, -OC (═ O) NH-, -NHC (═ O) -, -NHC (═ O) NH-or-O-, and PFPE2 represents a poly (oxyperfluoroalkylene) structure as a core and having X and X on both sides thereof³Or X⁴Groups of linked terminal structures.

In the above formula [3]In (1) as R⁵And R⁷And R⁶And R⁸In the above formula, the alkyl group having 1 to 5 carbon atoms is represented by the above R¹And R³The alkyl group exemplified in (1).

As R⁵And R⁷Preferably methyl or ethyl.

As R⁶And R⁸Preferably methyl or phenyl.

Further, r and s are preferably 3.

Furthermore as L⁵And L⁶In 1E CSpecific examples of the alkylene group of 5 include those mentioned for L¹～L⁴The alkylene group exemplified in (1).

In the specific examples of the above alkylene group, L is⁵And L⁶Preferably an ethylene group or a1, 3-propylene group, more preferably a1, 3-propylene group.

As the above X³And X⁴preferably-OC (═ O) -or-OC (═ O) NH-, more preferably-OC (═ O) NH-, and still more preferably-OC (═ O) NH- (wherein, O represents the binding end to PFPE 2).

PFPE2 represents a core of a poly (oxyperfluoroalkylene) structure having X and X on both sides thereof³Or X⁴Groups of linked terminal structures.

As a poly (oxyperfluoroalkylene) structure, and on both sides thereof with X³And X⁴Examples of the terminal structure of the ligation include those exemplified in PFPE1.

The perfluoropolyether (b3) is obtained, for example, by a method in which, in a compound having hydroxyl groups at both ends of a group containing a poly (oxyperfluoroalkylene) group, an alkoxysilane having an isocyanate group, such as (3-isocyanatopropyl) trimethoxysilane, is reacted with the hydroxyl groups at both ends.

In the curable composition of the present invention, perfluoropolyether (b3) may be used alone or in combination of two or more.

[ (b4) perfluoropolyether having an active energy ray-polymerizable group via a poly (oxyalkylene) group at one end of the molecular chain containing a poly (oxyperfluoroalkylene) group and a hydroxyl group via a poly (oxyalkylene) group at the other end of the molecular chain ]

The active energy ray-polymerizable group is not limited to one having 1 active energy ray-polymerizable moiety such as a (meth) acryloyl moiety, and may have 2 or more active energy ray-polymerizable moieties, and examples thereof include structures represented by the following formulas [ A1] to [ A5], and structures in which an acryloyl group in these structures is replaced by a methacryloyl group.

Specific examples of such perfluoropolyether (b4) include the compounds shown below and compounds obtained by replacing the acryloyl group in these compounds with a methacryloyl group. In the structural formulae, A represents a structure represented by the formulae [ A1] to [ A5], PFPE represents a group having a poly (oxyperfluoroalkylene) structure as a core and a terminal structure connected to an oxyalkylene group on both sides thereof, and n represents the number of repeating units of an oxyethylene group, preferably 1 to 10.

The poly (oxyperfluoroalkylene) structure may include those specifically mentioned in the above-mentioned poly (oxyperfluoroalkylene) group as a suitable structure.

Examples of the terminal structure to which oxyalkylene groups are bonded on both sides thereof include, in the case where the terminal structure is bonded to the-O-terminal of a poly (oxyperfluoroalkylene) group, a C2 or C3 alkylene group substituted with 1 to 3 fluorine atoms, or a O-CF group₂C (═ O) -, at the fluoroalkylene end of the poly (oxyperfluoroalkylene) group (e.g., -CF)₂-、-C(CF₃) Examples of the linkage of F-) include O- (alkylene group having 2 or 3 carbon atoms substituted with 1 to 3 fluorine atoms) -, O-CF₂C(＝O)-(＊＊Both represent bound ends to poly (oxyperfluoroalkylene) groups).

Examples of the alkylene group having 2 or 3 carbon atoms substituted with 1 to 3 fluorine atoms include, for example, -CHFCH₂-、-CF₂CH₂-、-CF₂CHF-、-CHFCH₂CH₂-、-CF₂CH₂CH₂-、-CF₂CHFCH₂-etc., preferably-CF₂CH₂-。

AO--(CH₂CH₂O)_n-PFPE-(OCH₂CH₂)_nOH

The perfluoropolyether (b4) is produced, for example, by a method in which 2- (meth) acryloyloxyethyl isocyanate is subjected to a urethanization reaction with respect to the hydroxyl group at one end of both ends of a poly (oxyperfluoroalkylene) group in a compound having hydroxyl groups at both ends via the poly (oxyalkylene) group, a method in which (meth) acryloyl chloride or chloromethylstyrene is subjected to a dehydrochlorination reaction, or a method in which (meth) acrylic acid is subjected to a dehydration reaction; a method of esterifying itaconic anhydride, and the like.

Among these methods, a method of subjecting 2- (meth) acryloyloxyethyl isocyanate to a urethanization reaction with respect to a hydroxyl group at one end of both ends or a method of subjecting (meth) acryloyl chloride or chloromethyl styrene to a dehydrochlorination reaction with respect to the hydroxyl group in a compound having a hydroxyl group at both ends of a poly (oxyperfluoroalkylene) group via a poly (oxyalkylene) group is particularly preferable in terms of easiness of the reaction.

[ (b5) perfluoropolyether having active energy ray-polymerizable group via poly (oxyalkylene) group or via poly (oxyalkylene) group and 1 urethane bond in this order at both ends of molecular chain containing poly (oxyperfluoroalkylene) group ]

The active energy ray-polymerizable group is not limited to one having 1 active energy ray-polymerizable moiety such as a (meth) acryloyl moiety, and may have 2 or more active energy ray-polymerizable moieties, and examples thereof include structures represented by the above formulas [ A1] to [ A5], and structures in which an acryloyl group in these structures is replaced by a methacryloyl group.

Such perfluoropolyether (b5) is preferably a compound represented by the following structural formula or a compound obtained by substituting an acryloyl group in these compounds with a methacryloyl group, because it is easy to industrially produce the perfluoropolyether. In the structural formula, A represents 1 of the structures represented by the formulae [ A1] to [ A5], PFPE represents a group having a poly (oxyperfluoroalkylene) structure as a core and terminal structures connected to oxyalkylene groups on both sides thereof, and n independently represents the number of repeating units of oxyethylene groups, preferably 1 to 15, more preferably 5 to 12, and still more preferably 7 to 12.

A-O-(CH₂CH₂O)_n-PFPE-(OCH₂CH₂)_n-O-A

The poly (oxyperfluoroalkylene) structure may include those specifically mentioned in the above-mentioned poly (oxyperfluoroalkylene) group as a suitable structure.

Examples of the terminal structure to which oxyalkylene groups are bonded on both sides thereof include, in the case where the terminal structure is bonded to the-O-terminal of a poly (oxyperfluoroalkylene) group, a C2 or C3 alkylene group substituted with 1 to 3 fluorine atoms, or a O-CF group₂C (═ O) -, at the fluoroalkylene end of the poly (oxyperfluoroalkylene) group (e.g., -CF)₂-、-C(CF₃) Examples of the linkage of F-) include O- (alkylene group having 2 or 3 carbon atoms substituted with 1 to 3 fluorine atoms) -, O-CF₂C (═ O) - (. O.) denotes the binding end to the poly (oxyperfluoroalkylene) group.

Examples of the alkylene group having 2 or 3 carbon atoms substituted with 1 to 3 fluorine atoms include, for example, -CHFCH₂-、-CF₂CH₂-、-CF₂CHF-、-CHFCH₂CH₂-、-CF₂CH₂CH₂-、-CF₂CHFCH₂-, preferably-CF₂CH₂-。

The perfluoropolyether (b5) used in the present invention is preferably a perfluoropolyether in which a poly (oxyperfluoroalkylene) group and 1 urethane bond are sequentially bonded to both ends of a molecular chain containing the poly (oxyperfluoroalkylene) group, that is, a poly (oxyalkylene) group is bonded to each of both ends of a molecular chain containing the poly (oxyperfluoroalkylene) group, 1 urethane bond is bonded to each of the poly (oxyalkylene) groups at both ends, and an active energy ray-polymerizable group is bonded to each of the urethane bonds at both ends. Further, among the above perfluoropolyethers, those having an active energy ray-polymerizable group of at least 2 active energy ray-polymerizable moieties are preferable.

The perfluoropolyether (b5) is obtained, for example, by a method in which, among compounds having hydroxyl groups at both ends of a poly (oxyperfluoroalkylene) group via a poly (oxyalkylene) group, an isocyanate compound having a polymerizable group such as 2- (meth) acryloyloxyethyl isocyanate, 1-bis ((meth) acryloyloxymethyl) ethyl isocyanate or the like is subjected to a urethanization reaction with respect to the hydroxyl groups at both ends thereof, a method in which (meth) acryloyl chloride or chloromethylstyrene is subjected to a dehydrochlorination reaction, a method in which (meth) acrylic acid is subjected to a dehydration reaction, and a method in which itaconic anhydride is subjected to an esterification reaction.

Among these methods, a method of subjecting an isocyanate compound having a polymerizable group such as 2- (meth) acryloyloxyethyl isocyanate or 1, 1-bis ((meth) acryloyloxymethyl) ethyl isocyanate to a urethanization reaction with respect to the hydroxyl group at both ends of a poly (oxyperfluoroalkylene) group of a compound having a hydroxyl group at both ends via a poly (oxyalkylene) group, or a method of subjecting (meth) acryloyl chloride or chloromethylstyrene to a dehydrochlorination reaction with respect to the hydroxyl group is particularly preferable in terms of easiness of the reaction.

[ (b6) perfluoropolyether having active energy ray-polymerizable groups via urethane bonds at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group (excluding perfluoropolyethers having a poly (oxyalkylene) group between the poly (oxyperfluoroalkylene) group and the urethane bond) ]

The perfluoropolyether (b6) is not limited to having 1 active energy ray-polymerizable group such as a (meth) acryloyl group at both ends, and may have 2 or more active energy ray-polymerizable groups at both ends, and examples of the terminal structure containing an active energy ray-polymerizable group include structures of the above-mentioned formulas [ a1] to [ a5], and structures in which acryloyl groups in these structures are replaced with methacryloyl groups.

The perfluoropolyether (b6) is preferably, for example, a perfluoropolyether having at least 2 active energy ray-polymerizable groups at both ends and a perfluoropolyether having at least 3 active energy ray-polymerizable groups at both ends.

Examples of such perfluoropolyether (b6) include compounds represented by the following formula [4 ].

(in the formula [4]]Wherein A represents the above formula [ A1]]-formula [ A5]PFPE represents a group having a poly (oxyperfluoroalkylene) structure as a core and terminal structures connected to oxyalkylene groups on both sides thereof, n independently represents an integer of 1 to 5, L⁷Represents a residue of valence n +1 in which OH is removed from an alcohol of valence n + 1. )

The poly (oxyperfluoroalkylene) structure may include those specifically mentioned in the above-mentioned poly (oxyperfluoroalkylene) group as a suitable structure.

Examples of the terminal structure to which oxyalkylene groups are bonded on both sides thereof include, in the case where the terminal structure is bonded to the-O-terminal of a poly (oxyperfluoroalkylene) group, a C2 or C3 alkylene group substituted with 1 to 3 fluorine atoms, or a O-CF group₂C (═ O) -, at the fluoroalkylene end of the poly (oxyperfluoroalkylene) group (e.g., -CF)₂-、-C(CF₃) Examples of the linkage of F-) include O- (alkylene group having 2 or 3 carbon atoms substituted with 1 to 3 fluorine atoms) -, O-CF₂C (═ O) - (. O.) denotes the binding end to the poly (oxyperfluoroalkylene) group.

Examples of the alkylene group having 2 or 3 carbon atoms substituted with 1 to 3 fluorine atoms include, for example, -CHFCH₂-、-CF₂CH₂-、-CF₂CHF-、-CHFCH₂CH₂-、-CF₂CH₂CH₂-、-CF₂CHFCH₂-, preferably-CF₂CH₂-。

As the above formula [4]Partial structure of the shown compound (A-NHC (═ O)_nL⁷Examples thereof include the following formula [ B1]-formula [ B12]The structure shown.

(in the formulae [ B1] to [ B12], A represents 1 of the structures represented by the formulae [ A1] to [ A5] and the structures in which acryloyl groups are replaced with methacryloyl groups.)

In the structures represented by formulas [ B1] to [ B12], formulas [ B1] and [ B2] correspond to the case where n is 1, formulas [ B3] to [ B6] correspond to the case where n is 2, formulas [ B7] to [ B9] correspond to the case where n is 3, and formulas [ B10] to [ B12] correspond to the case where n is 5.

Among them, the structure represented by the formula [ B3] is preferable, and the combination of the formula [ B3] and the formula [ A3] is particularly preferable.

Preferable perfluoropolyether (b6) includes a compound having a partial structure represented by the following formula [5 ].

The partial structure represented by the formula [5] corresponds to a portion obtained by removing a — NHC (═ O) from the compound represented by the formula [4 ].

Formula [5]]Wherein n represents a repeating unit- [ OCF ]₂CF₂]A number of and a repeating unit of- [ OCF ]₂]The total number of-units is preferably in the range of 5 to 30, more preferably in the range of 7 to 21. Furthermore, the repeating unit- [ OCF ]₂CF₂]A number of and a repeating unit of- [ OCF ]₂]The ratio of the numbers of-is preferably 2: 1-1: 2, more preferably about 1: 1, in the above range. The combination of these repeating units may be either block combination or random combination.

The perfluoropolyether (b6) can be obtained, for example, by reacting an isocyanate compound having a polymerizable group, i.e., a compound having an isocyanate group (for example, 2- (meth) acryloyloxyethyl isocyanate or 1, 1-bis ((meth) acryloyloxymethyl) ethyl isocyanate) bonded to a bond in the structures represented by the formulae [ a1] to [ a5] and a structure in which an acryloyl group in these structures is replaced by a methacryloyl group, with a hydroxyl group present at both ends of the compound represented by the formula [6], to form a urethane bond.

(HO)_nL⁷-O-PFPE-O-L⁷(OH)_n [6]

(wherein PFPE, L⁷And n is the same as the above formula [4]]The same meaning is used. )

Examples of the preferable perfluoropolyether (b6) include perfluoropolyether compounds having at least 3 active energy ray-polymerizable groups at each end of the molecular chain containing a poly (oxyperfluoroalkylene) group via a urethane bond (except for the perfluoropolyether having a poly (oxyalkylene) group between the poly (oxyperfluoroalkylene) group and the urethane bond).

The perfluoropolyether compound having polymerizable groups at both ends is preferably a compound having a partial structure represented by the formula [5 ].

As the preferable component (perfluoropolyether) of the component (b), perfluoropolyether (b6) is mentioned, that is, (b6) perfluoropolyether having an active energy ray-polymerizable group via a urethane bond at both ends of a molecular chain containing a poly (oxyperfluoroalkylene) group (excluding perfluoropolyether having a poly (oxyperfluoroalkylene) group between the poly (oxyperfluoroalkylene) group and the urethane bond).

[ (c) polymerization initiator generating free radical by active energy ray ]

A polymerization initiator (hereinafter, also simply referred to as "c polymerization initiator") which generates radicals by active energy rays is preferably used in the curable composition capable of forming a hard coat layer, and is a polymerization initiator which generates radicals by active energy rays such as electron rays, ultraviolet rays, and X-rays, particularly by irradiation with ultraviolet rays.

Examples of the polymerization initiator (c) include benzoins, alkylbenzones, thioxanthones, azones, azides, diazones, o-quinonediazines, acylphosphine oxides, oxime esters, organic peroxides, benzophenones, biscoumarins, bisimidazoles, titanocenes, thiols, halogenated hydrocarbons, trichloromethyltriazines, iodophorsOnium salts, sulfonium salts and the likeAnd (3) salts. These may be used singly or in combination of two or more.

Among the specific examples of the polymerization initiator (c), in the present invention, alkylbenzophenones are preferably used from the viewpoint of transparency, surface curability, and film curability. By using the alkylphenones, a cured film having further improved scratch resistance can be obtained.

Examples of the above-mentioned alkylphenones include α -hydroxyalkylbenzones such as 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-1- (4- (2-hydroxyethoxy) phenyl) -2-methylpropan-1-one, and 2-hydroxy-1- (4- (4- (2-hydroxy-2-methylpropanoyl) benzyl) phenyl) -2-methylpropan-1-one; α -aminoalkylbenzones such as 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropan-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one; 2, 2-dimethoxy-1, 2-diphenylethan-1-one; methyl benzoylformate.

In the present invention, it is desirable that the polymerization initiator (c) is used in a proportion of 1 to 20 parts by mass, preferably 2 to 10 parts by mass, relative to 100 parts by mass of the oxyalkylene-modified polyfunctional monomer (a) having at least 3 active energy ray-polymerizable groups.

[ (d) solvent ]

The curable composition capable of forming a hard coat layer further contains (d) a solvent, and is in the form of a varnish (film-forming material).

The solvent contained in the curable composition is a solvent having a solvent swelling degree of the film base material at its normal boiling point of 70% or less. The solvent has a solvent swelling degree of preferably 50% or less, more preferably 30% or less.

Here, the solvent swelling degree is a value calculated by measuring the mass immediately after immersion and after drying in a solvent near the boiling point by an analytical balance according to the following equation.

Degree of solvent swelling [% ]]＝(m₁-m₀)÷m₀×100

(m₀: mass m of test piece dried after immersion in solvent₁: quality of test piece immersed in solvent)

The solvent is appropriately selected in consideration of the solubility of the components (a) to (c), the workability in coating for forming a cured film (hard coat layer) described later, and the drying property before and after curing.

Examples of the solvent include aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, and tetralin; aliphatic or alicyclic hydrocarbons such as n-hexane, n-heptane, mineral spirits, and cyclohexane; halogenated substances such as chloromethane, bromomethane, iodomethane, dichloromethane, chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene, o-dichlorobenzene and the like; esters or ester ethers such as ethyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, and propylene glycol monomethyl ether acetate; diethyl ether, tetrahydrofuran, 1, 4-bisEthers such as alkane, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, and propylene glycol mono-n-butyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, and cyclohexanone; methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, 2-ethylhexyl alcohol, benzyl alcohol, ethylene glycol, etcAlcohols; amides such as N, N-dimethylformamide, N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxides such as dimethyl sulfoxide, and a solvent obtained by mixing 2 or more of these solvents.

Examples of the solvent when the film substrate is used as the Thermoplastic Polyurethane (TPU) film include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 2-ethylhexyl alcohol, benzyl alcohol, and ethylene glycol, and solvents in which 2 or more of these solvents are mixed, and methanol is preferable.

(d) The amount of the solvent used is not particularly limited, and for example, the solid content concentration in the curable composition capable of forming a hard coat layer is 1 to 70% by mass, preferably 5 to 50% by mass. The solid content concentration (also referred to as nonvolatile content concentration) herein means the content of a solid content (a component obtained by removing a solvent component from all components) with respect to the total mass (total mass) of the above-mentioned components (a) to (d) (and other additives as needed) of the curable composition.

[ other additives ]

In addition, in the curable composition capable of forming a hard coat layer, if necessary, additives generally added, for example, a polymerization inhibitor, a photosensitizing agent, a leveling agent, a surfactant, an adhesion imparting agent, a plasticizer, an ultraviolet absorber, an antioxidant, a storage stabilizer, an antistatic agent, an inorganic filler, a pigment, and a dye may be appropriately blended as long as the effects of the present invention are not impaired.

The method for producing a scratch-resistant hard coating film according to the present invention comprises at least the following steps: a step of applying the curable composition capable of forming a hard coat layer on a film substrate to form a coating film; and a step of irradiating the coating film with an active energy ray to cure the coating film.

Examples of the film substrate include a resin film selected from polyesters such as Thermoplastic Polyurethane (TPU), polyethylene terephthalate (PET), polybutylene terephthalate (PBT) and polyethylene naphthalate (PEN), polycarbonates, polymethacrylates, polystyrene, polyolefins, polyamides, polyimides and triacetylcellulose, and a Thermoplastic Polyurethane (TPU) film is preferable from the viewpoint of scratch resistance and stretchability of the resulting hard coat film.

When a solvent having a degree of solvent swelling of the Thermoplastic Polyurethane (TPU) film at its normal boiling point of 70% or less is used as the solvent contained in the curable composition, a hard coating film having stretchability in addition to excellent scratch resistance can be produced.

As a method of applying the coating to the film base material, for example, a casting coating method, a spin coating method, a blade coating method, a dip coating method, a roll coating method, a spray coating method, a bar coating method, a die coating method, an ink jet method, and a printing method (for example, a relief printing method, a gravure printing method, a planographic printing method, and a screen printing method) can be appropriately selected. It is also preferable that the curable composition is filtered in advance using a filter having a pore size of about 0.2 μm or the like and then applied.

After a coating film is formed by applying a curable composition to a film base material, the coating film is predried by a heating device such as an electric heating plate or an oven as necessary to remove the solvent (solvent removal step). The conditions for the heat drying in this case are preferably, for example, about 30 seconds to 10 minutes at 40 to 120 ℃.

After drying, the coating film is cured by irradiation with active energy rays such as ultraviolet rays. Examples of the active energy ray include ultraviolet rays, electron beams, and X-rays, and ultraviolet rays are particularly preferable. Examples of the light source used for the ultraviolet irradiation include a solar ray, a chemical lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, and a UV-LED.

Further, the polymerization can be terminated by post-baking, specifically, by heating with a heating device such as a hot plate or an oven.

The film thickness of the hard coat layer obtained in this way is preferably 1 μm to 20 μm, more preferably 1 μm to 10 μm.

The method for producing a scratch-resistant hard coat film of the present invention can produce a hard coat film having a hard coat layer on at least one surface (surface) of a film base material. The hard coat film is suitably used for protecting the surface of various display elements such as a flexible display.

Examples

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to the following examples.

In the examples, the apparatus and conditions used for the preparation of the sample and the analysis of the physical properties were as follows.

(1) Electric heating plate stirrer

The device comprises the following steps: IKA Plate manufactured by IKA ジャパン (strain)

(2) Coating by bar coating

The device comprises the following steps: PM-9050MC (manufactured by strain) エスエムテー

Stick: オーエスジーシステムプロダクツ A-Bar OSP-22 manufactured by Kabushiki Kaisha, maximum wet film thickness 22 μm (equivalent to wire Bar #9)

Coating speed: 4 m/min

(3) Baking oven

The device comprises the following steps: アドバンテック dustless drier DRC433FA manufactured by DONGYANG (DONG, Inc.)

(4) UV curing

The device comprises the following steps: ヘレウス strain CV-110QC-G

Lamp: ヘレウス high-pressure mercury lamp manufactured by Kabushiki Kaisha H-bulb

(5) Determination of storage elastic modulus

The device comprises the following steps: automatic braking viscoelasticity measuring instrument レオバイブロン (registered trademark) DDV-01GP (trademark) of Tokyo エー & アンド & デイ

Sample size: length 4mm x width 1mm

Measurement mode: stretching

Measuring temperature: 25 deg.C

Measuring the amplitude: 4 μm

Measuring frequency: 10Hz

(6) Analytical balance

The device comprises the following steps: XSE205 manufactured by メトラー & トレド (strain)

(7) Gel Permeation Chromatography (GPC)

The device comprises the following steps: HLC-8220GPC manufactured by DONG ソー strain

Column: shodex (registered trademark) GPC K-804L, GPC K-805L manufactured by Showa Denko K.K

Column temperature: 40 deg.C

Eluent: tetrahydrofuran (THF)

A detector: RI (Ri)

(8) Scratch test

The device comprises the following steps: the reciprocating abrasion tester TRIBOGEAR TYPE manufactured by Xindong science (strain): 30S

Scanning speed: 3,000 mm/min

Scanning distance: 50mm

In addition, the abbreviation indicates the following meaning.

EOMA: ethylene oxide-modified polyfunctional acrylate [ アロニックス (registered trademark) MT-3553, manufactured by Toyo Seisaku-sho Ltd., functional group number 4 or more ]

PFPE: perfluoropolyether having 2 hydroxyl groups at both terminals without a poly (oxyalkylene) group [ Fomblin (registered trademark) T4, manufactured by ソルベイスペシャルティポリマーズ ]

BEI: 1, 1-bis (acryloyloxymethyl) ethyl isocyanate [ カレンズ (registered trademark) BEI manufactured by SHOWA DENKO K.K. ]

DOTDD: dioctyltin dinecanoate [ ネオスタン (registered trademark) U-830, manufactured by Nidong Kaishikai Co., Ltd ]

I2959: 2-hydroxy-1- (4- (2-hydroxyethoxy) phenyl) -2-methylpropan-1-one [ IRGACURE (registered trademark) 2959, manufactured by BASF ジャパン ]

TPU 1: polyurethane elastomer film [ ハイグレス DUS270-CER manufactured by シーダム Corp., thickness of 100 μm, storage elastic modulus of 92MPa (measured value) ]

TPU 2: polyurethane elastomer film [ ハイグレス DUS605-CER manufactured by シーダム Corp., thickness 100 μm, storage elastic modulus 159MPa (measured value) ]

PMMA: poly (methyl methacrylate) film [ テクノロイ S000 manufactured by Suzuki アクリル Kogyo Co., Ltd., thickness 125 μm ]

MeOH: methanol

EtOH: ethanol

IPA: 2-propanol

PGME: propylene glycol monomethyl ether

MEK: methyl ethyl ketone

MIBK: methyl isobutyl ketone

AcOEt: ethyl acetate

AcOBu: acetic acid butyl ester

[ reference example ] solvent swelling degree of film base Material

50mL of the solvent described in Table 1 was placed in a 100mL beaker, and heated with an electric hot plate stirrer so that the liquid temperature was close to the boiling point of the solvent. The test piece cut into 25 mm. times.25 mm was immersed therein for 3 minutes. After completion of the immersion, an excess solvent adhered to the surface of the test piece was wiped with a nonwoven cloth wiper [ BEMCOT (registered trademark) M-1 made by Xiaojin industries, Ltd.)]Gently wiped off, and the mass m of the test piece was immediately measured using an analytical balance₁. Next, the test piece was dried at room temperature (about 23 ℃ C.) for 24 hours, and the mass m of the test piece after drying was measured₀. The degree of solvent swelling was calculated by the following formula. The results are shown together in table 1.

Degree of solvent swelling [% ]]＝(m₁-m₀)÷m₀×100

TABLE 1

Production example 1 production of perfluoropolyether (SM) having 4 acryloyl groups at each end via urethane bond

PFPE1.19g (0.5mmol), BEI0.52g (2.0mmol), DOTDD0.017g (0.01 times of the total mass of PFPE and BEI), and MEK1.67g were charged into the threaded tube. The mixture was stirred at room temperature (about 23 ℃) for 24 hours using a stirrer, to obtain a 50 mass% MEK solution of SM as an objective compound.

Weight average molecular weight of the obtained SM as measured in terms of polystyrene by GPC: mw 3,000, dispersity: mw (weight average molecular weight)/Mn (number average molecular weight) was 1.2.

Examples 1 to 4 and comparative examples 1 to 6

The following components (1) to (4) were mixed to prepare a curable composition having a solid content of 40% by mass. Here, the solid component means a component other than the solvent.

(1) A polyfunctional monomer: EOMA 100 parts by mass

(2) Surface modifier: 0.2 part by mass of SM (in terms of solid content) produced in production example 1

(3) Polymerization initiator: i29593 parts by mass

(4) Solvent: 154.6 parts by mass of a solvent described in Table 2

The curable composition was applied to a film base material (size B5) shown in table 2 by bar coating to obtain a coating film. The coating film was dried in an oven at the temperature described in table 2 for 3 minutes to remove the solvent. The obtained film was irradiated with an exposure of 300mJ/cm in a nitrogen atmosphere²The hard coat film was formed to have a hard coat layer (cured film) having a thickness of about 5 μm by exposure to UV light.

The surface of the obtained hard coat layer was treated with steel wool (ボンスター (registered trademark) #0000 (ultra fine) manufactured by ボンスター casing strain) mounted on a reciprocating abrasion tester]Application of 500g/cm²The test piece was repeatedly rubbed 10 times, and the degree of damage was visually checked, and evaluated according to the following criteria. The results are shown together in Table 2. Further, assuming practical use as a hard coat layer, at least B is required, and a is desirable.

A: is not injured

B: is injured by less than 5mm

C: is injured by a length of more than 5mm

TABLE 2

As shown in table 2, it was found that the hard coat films (examples 1 to 3) produced using MeOH as a solvent having a low solvent swelling degree, that is, 70% or less, as a film base material used, and the hard coat film (example 4) produced using AcOEt exhibited excellent scratch resistance. On the other hand, it was found that the hard coating films using PGME (comparative examples 1 to 3) and MEK (comparative examples 4 to 6) as a solvent having a high solvent swelling degree, that is, more than 70% or a solvent in which the film base material is completely dissolved significantly reduced in scratch resistance.