JP2007216525A - Transparent protective panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To give excellent antistatic performance to a surface protection layer without spoiling abrasion resistance and transparency in a transparent protective panel in which the surface protection layer to be a hard coat layer is formed on a transparent resin substrate. <P>SOLUTION: In the transparent protective panel comprising the transparent resin substrate and the surface protection layer formed on the substrate, the surface protection layer is obtained by curing a curable resin composition containing an antistatic agent, and the curable resin composition containing the antistatic agent contains a monomeric component (A) and 1-5 pts.wt. of the antistatic agent (B) per 100 pts.wt. of the monomeric component (A). The monomeric component (A) contains 100 pts.wt. of a urethane acrylate (a-1) having at least nine radical-polymerizable functional groups and 0.1-42.9 pts.wt. of a polyfunctional (meth)acrylate (a-2) having a hydroxy group and at least three radical-polymerizable functional groups. The antistatic agent (B) comprises an ionic copolymer having a repeating unit containing an ester chain and a repeating unit having an ionic group. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transparent protective panel, and more particularly to a transparent protective panel used as a protective plate for a display screen of a mobile or the like such as a mobile phone or a digital camera.

  Display screens of various mobile devices such as mobile phones and digital cameras are generally formed of liquid crystal, and the surface is protected by a sheet-like transparent protective panel. Such a protective panel is formed from an acrylic resin such as polymethyl methacrylate or a transparent resin such as polycarbonate, but a hard coat layer is formed on the surface thereof in order to improve scratch resistance. Further, in such a transparent protective panel, an antistatic coating layer containing an antistatic agent is provided on the hard coating layer in order to prevent adhesion of dust and to prevent adverse effects on the device due to charging. Things have been done.

  By the way, recently, studies have been made to add various antistatic agents to the hard coat layer itself so that the hard coat layer has an antistatic function. It is difficult to have it and has not yet been put into practical use. That is, as antistatic agents, various metal oxides and organic antistatic agents such as amine compounds, sulfonic acid compounds, phosphoric acid compounds, and polyethylene glycol are known. When blended in the coat layer, various disadvantages occur. For example, metal oxides require a considerable amount of addition in order to develop sufficient antistatic ability. If the amount of addition is increased to develop antistatic ability, transparency may be impaired or Problems such as a drop in impact properties occur. In the case of an organic antistatic agent, if it is added to the hard coat layer in such an amount that sufficient antistatic ability is exhibited, the hardness of the hard coat layer is greatly reduced and the scratch resistance is increased. Problems such as deterioration of the original characteristics, stickiness, and non-permanent antistatic ability occur.

On the other hand, research and development of new antistatic agents are also actively conducted. For example, Patent Documents 1 and 2 include an ionic copolymer having a repeating unit containing an ester chain and a repeating unit having an ionic group. An antistatic agent is proposed.
Patent No. 2871115 Japanese Patent No. 3581719

  The antistatic agents disclosed in Patent Documents 1 and 2 as described above exhibit stable antistatic ability over a long period of time and have good compatibility with resins. However, even in such an antistatic agent, when blended in the hard coat layer in such an amount that good antistatic ability is exhibited, transparency is not impaired, but a decrease in hardness cannot be avoided, The problem that the original characteristic of the hard coat layer, namely scratch resistance, is still not solved.

  Accordingly, an object of the present invention is to provide an excellent antistatic ability in a transparent protective panel in which a surface protective layer serving as a hard coat layer is formed on a transparent resin substrate without impairing the scratch resistance and transparency of the surface protective layer. It is to provide a transparent protective panel to which is provided.

According to the present invention, in a transparent protective panel comprising a transparent resin substrate and a surface protective layer provided on the substrate,
The surface protective layer is obtained by curing an antistatic agent-containing curable resin composition,
The antistatic agent-containing curable composition contains the monomer component (A) and 0.5 to 5 parts by weight of the antistatic agent (B) per 100 parts by weight of the monomer component (A).
The monomer component (A) has the following composition:
(A-1) 100 folds of urethane acrylate containing 9 or more radical polymerizable functional groups
Amount part;
(A-2) Multifunctional (meth) a having a hydroxyl group and three or more radical polymerizable functional groups
0.1 to 42.9 parts by weight of chlorate;
And having
The antistatic agent (B) comprises an ionic copolymer having a repeating unit containing an ester chain and a repeating unit having an ionic group, thereby providing a transparent protective panel.

In the transparent protective panel of the present invention, the following modes are suitable.
(I) The repeating unit containing an ester chain in the ionic copolymer has the following formula (1):
_{- (CRX-CH 2) -} ... (1)
In the formula, R is a hydrogen atom or a methyl group,
X is the following formula:
HO— (R ¹ —COO—) _n — (CH ₂ ) _m —OOC—
(Here, R ¹ is a divalent aliphatic hydrocarbon group, n is 2 to 200, and m is 1)
An integer of ~ 8)
A monovalent group represented by:
Or the following formula (2):
_{- (CRY-CH 2) -} ... (2)
In the formula, R is a group as defined in the formula (1),
Y is the following formula:
R ² —O— (CO—R ³ —O—) _p —R ⁴ —
Here, p is an integer of 2 to 200, and R ² is an alkyl group having 1 to 20 carbon atoms.
Or an aralkyl group, R ³ is a divalent aliphatic hydrocarbon group,
_{-CONH-ph -, - CONH-} C (CH 3) 2 -ph-,
_{-CONHCO -, - CONH- (CH 2} ) q -OOC-, or -CO-
Where ph is an optionally substituted phenylene group, q
Is an integer from 1 to 10),
A monovalent group represented by:
Represented by
(II) The repeating unit having an ionic group in the ionic copolymer is represented by the following formula (3):
—CH ₂ —CRZ— (3)
In the formula, R is as defined in the formula (1),
Z is an anionic group or a cationic group,
Represented by
(III) The ionic copolymer has an intrinsic viscosity ηinh of 0.02 or more, and a repeating unit containing an ester chain and a repeating unit having an ionic group in a weight ratio of 10:90 to 90:10. Contain.
(IV) The transparent resin substrate is composed of a polycarbonate resin substrate, an acrylic resin substrate, or a laminate having an acrylic resin layer formed on at least one surface of the polycarbonate resin layer.

  In the transparent protective panel of the present invention, the surface protective layer provided on the transparent resin substrate functions as a hard coat layer and has transparency and scratch resistance. In addition to the characteristics as a hard coat layer, it has excellent antistatic ability. For this reason, it is not necessary to further provide an antistatic layer on the surface protective layer, and the hard coat layer and the antistatic layer are not separated into two layers, which is extremely advantageous in reducing the production cost. .

  The transparent protective panel of the present invention has a structure in which a surface protective layer is provided on a transparent resin substrate, but the transparent resin substrate is not particularly limited as long as it has a certain strength and transparency, Although it may be formed of a transparent resin known per se, it is generally formed of an acrylic resin such as polymethyl methacrylate (PMMA) or polycarbonate (PC) from the viewpoint of adhesion to the surface protective layer. Is done. For example, the transparent resin substrate may be an acrylic resin substrate such as PPMA, a polycarbonate resin substrate, or a laminated resin substrate in which an acrylic resin layer is laminated on at least one surface of a polycarbonate resin layer. Furthermore, the thickness of the transparent resin substrate is not particularly limited and is appropriately determined according to the use of the transparent protective panel. Usually, when applied to a mobile display screen such as a mobile phone or a digital camera, The thickness is about 0.1 to 5 mm.

  As described above, the surface protective layer provided on the transparent resin substrate has a function as an antistatic layer as well as a function as a hard coat layer. For this reason, such a surface protective layer includes a specific monomer. It is formed by curing an antistatic agent-containing curable resin composition comprising a component (A) and a specific antistatic agent (B).

<Monomer component (A)>
As the monomer component (A) in such a curable composition, the following urethane acrylate (a-1) and hydroxyl group-containing polyfunctional (meth) acrylate (a-2) are used in combination.

(A-1) Urethane acrylate:
Urethane acrylate is obtained by polyaddition reaction of diisocyanate and (meth) acrylate having a plurality of hydroxyl groups, and particularly has 9 or more radical polymerizable groups (that is, acryloyl group or methacryloyl group). Nine or more functional ones are used. That is, it is possible to form a dense layer with high hardness by using such a 9-functional or higher urethane acrylate. For example, even if it is polyfunctional, if the number of radical polymerizable groups is less than 9, it becomes difficult to form a layer having high hardness, and the resulting surface protective layer has a low function as a hard coat layer, and has scratch resistance. It will be unsatisfactory.

  In such urethane acrylate, diisocyanate is not limited to this, but tolylene diisocyanate, xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 3,3′-dimethyl. Aromatic diisocyanates such as -4,4'-diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, trimethylhexa Examples thereof include aliphatic diisocyanates such as methylene diisocyanate.

  In addition, the (meth) acrylate having a plurality of hydroxyl groups used for forming the urethane acrylate is not limited to this, but includes trimethylolpropane (meth) acrylate, trimethylolethane (meth) acrylate, Examples include pentaerythritol (meth) acrylate and trimethylolmethane (meth) acrylate.

  That is, the urethane acrylate used in the present invention can be obtained by reacting the diisocyanate and the hydroxyl group-containing (meth) acrylate in an amount ratio such that the (meth) acrylate is 9 times mole or more.

  The above-mentioned 9-functional or higher urethane acrylate (a-1) is very high in viscosity by itself and poor in workability, and is usually commercially available in a paste form containing about 5 to 20% organic solvent. And used in such a form.

(A-2) Hydroxyl group-containing polyfunctional (meth) acrylate:
The polyfunctional (meth) acrylate used in combination with the above 9-functional or higher urethane acrylate contains a hydroxyl group and has 3 or more radically polymerizable unsaturated groups. Such a polyfunctional (meth) acrylate functions as a compatibilizer for the antistatic agent described later. By using such a polyfunctional (meth) acrylate in combination, transparency and scratch resistance are impaired. Therefore, it is possible to develop an excellent antistatic ability.

  Such a trifunctional or higher functional hydroxyl group-containing (meth) acrylate is not limited to this, but examples include pentaerythritol tri (meth) acrylate.

  In the present invention, the above-mentioned trifunctional or higher functional hydroxyl group-containing (meth) acrylate is 0.1 to 42.9 parts by weight, particularly 5.3 to 25 parts by weight per 100 parts by weight of the above-mentioned (a-1) urethane acrylate. It is important to use in parts quantity. That is, as will be apparent from the examples described later, if this amount is larger than the above range, there is no problem in terms of transparency and scratch resistance, but the surface resistance value increases and antistatic properties are prevented. Performance will be reduced. Further, when the trifunctional or higher functional hydroxyl group-containing (meth) acrylate is not used or when the amount used is less than the above range, the antistatic agent is not compatibilized and the transparency is impaired. This is because it cannot be used as a protective panel.

Other monomers;
Moreover, in this invention, in addition to the said monomer (a-1) and (a-2), if necessary, the polyfunctional (meth) acrylate (a-3) which does not contain a hydroxyl group can be used. . Such a polyfunctional (meth) acrylate is trifunctional or more, that is, has three or more radical polymerizable groups such as acryloyl group and methacryloyl group, and does not contain a hydroxyl group (a- It is different from the hydroxyl group-containing polyfunctional (meth) acrylate of 2). Such a polyfunctional (meth) acrylate not containing a hydroxyl group is used as a so-called diluent. That is, the urethane acrylate of component (a-1) described above is itself highly viscous. Therefore, a curable composition containing such component (a-1) in the monomer component (A) is used. In the case of coating, a solvent is usually used. However, the amount of solvent used may be significantly limited, or it may be desirable to coat the curable composition without using any solvent. In such a case, when this polyfunctional (meth) acrylate containing no hydroxyl group is used as a diluent, the hardness, transparency and antistatic ability of the film (surface protective layer) formed by curing are reduced. In addition, the viscosity of the curable composition is reduced without impairing the compatibility with the antistatic agent described later, and the curable composition is coated without using a solvent or using a very small amount of the solvent. It becomes possible to do.

  Examples of such polyfunctional (meth) acrylates that do not contain hydroxyl groups are trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylol methanetri Examples thereof include (meth) acrylate and pentaerythritol tetra (meth) acrylate.

  The amount of the polyfunctional (meth) acrylate (a-3) that does not contain such a hydroxyl group varies depending on the type of urethane acrylate (a-1) used. For example, the radically polymerizable functional group as urethane acrylate (a-1). When a product having a large number of is used, it is necessary to use a relatively large amount of polyfunctional (meth) acrylate (a-3) in order to lower the viscosity, and the radical polymerizable functional group When the urethane acrylate (a-1) having a small number (for example, about 9) is used, the amount of the polyfunctional (meth) acrylate (a-3) used can be reduced by a relatively small amount. . However, if the amount used is larger than necessary, the antistatic ability and hardness of the formed film may be reduced. Accordingly, the amount of the polyfunctional (meth) acrylate (a-3) not containing a hydroxyl group should be in the range of 60 parts by weight or less per 100 parts by weight of the (a-1) urethane acrylate. .

  In the present invention, as the monomer component (A), it is most preferable to use a monomer other than the above (a-1) and (a-2) in order to form a surface protective layer having high hardness. However, as long as the properties such as hardness are not impaired, the amount is small (usually 30 parts by weight or less per 100 parts by weight of the total amount of the monomers (a-1) and (a-2)). It is also possible to use a radically polymerizable monomer, for example, a bifunctional or lower (meth) acrylate compound.

<Antistatic agent (B)>
In the present invention, as the antistatic agent used together with the monomer component (A), an ionic copolymer having a repeating unit containing an ester chain and a repeating unit having an ionic group is used. That is, since the ionic polymer contains a repeating unit containing an ester chain, it is effectively compatible with the above-described monomer component (A) having a (meth) acrylic segment. The monomer component (A) is cured and dispersed in the surface protective layer obtained without curing, the transparency of the surface protective layer is not impaired, the hardness of the surface protective layer is not lowered, and stickiness is not generated. In addition, excellent scratch resistance can be ensured, and further, the surface resistance of the surface protective layer can be stably suppressed to a low range over a long period of time, and permanent antistatic ability can be imparted.

Such ionic polymers are known per se and are disclosed in, for example, Japanese Patent No. 3581719 and Japanese Patent No. 2871115. That is, the repeating unit containing an ester chain in the ionic copolymer is, for example, the formula (1):
_{- (CRX-CH 2) -} ... (1)
In the formula, R is a hydrogen atom or a methyl group,
X is the following formula:
HO— (R ¹ —COO—) _n — (CH ₂ ) _m —OOC—
(Wherein R ¹ is a divalent aliphatic hydrocarbon group, and n is 2 to 200, particularly 2
~ 100, most preferably an integer of 2-50, m is 1-8, especially 2-4.
Is an integer)
A monovalent group represented by:
It is represented by

In the above formula (1), preferred examples of the divalent aliphatic hydrocarbon group represented by the group R ¹ in the group X include those having 3 to 8 branched or straight chain carbon atoms, In particular,
_{-CH 2 CH (CH 3) -CH} 2 CH 2 -,
_{-CH 2 CH (CH 2 CH 3} ) -CH 2 CH 2 -,
_{-CH 2 CH 2 CH 2 CH 2} CH 2 -
_{-CH 2 C (CH 3) 2} -CH 2 CH 2 -
Etc. can be illustrated.

Such a repeating unit represented by the formula (1) is represented by the following formula (1a):
HO— (R ¹ —COO—) _n — (CH ₂ ) _m —OOC—CR═CH ₂ (1a)
In the formula, R, R ¹ , n and m are as shown in the formula (1),
It can introduce | transduce by the copolymerization using the (meth) acrylate compound represented by these as a monomer.

Moreover, as a repeating unit containing an ester chain in the ionic copolymer, the formula (2):
_{- (CRY-CH 2) -} ... (2)
In the formula, R is a group as defined in the formula (1), that is, a hydrogen atom or a methyl group,
Y is the following formula:
R ² —O— (CO—R ³ —O—) _p —R ⁴ —
Here, p is an integer of 2 to 200, particularly 2 to 100, and R ² has 1 to ² carbon atoms.
0 alkyl group or aralkyl group, and R ³ is a divalent aliphatic hydrocarbon
A group, -CONH-ph -, - CONH -C (CH 3) 2 -ph-,
-CONHCO-,
-CONH- _{(CH 2)} q -OOC-, or -CO- (where, ph
Is a phenylene group which may have a substituent, and q is an integer of 1 to 10.
is there),
A monovalent group represented by:
It is represented by

In the repeating unit of the above formula (2), the group R ² in the group Y is particularly preferably a linear or branched alkyl group, and suitable examples thereof include
_{CH 3 -, CH 3 CH 2} -, CH 3 CH 2 CH 2 -, CH 3 (CH 2) 3 -,
_{CH 3 (CH 2) 4 -} , (CH 3) CH-,
_{CH 3 - (CH 2) 3} -CH (C 2 H 5) CH 2 -,
Etc. can be illustrated.

Further, examples of the group R ³ in the group Y include those exemplified as preferred examples of the divalent aliphatic hydrocarbon group represented by the group R ¹ in the group X of the formula (1) described above.

Furthermore, examples of the substituent that the phenylene group in the group represented by the group R ³ may have include an alkyl group having 1 to 20 carbon atoms or a halogen atom. The number of such substituents is not limited to one, and may be bonded to the phenylene group by an upper limit of four.

The repeating unit represented by the above formula (2) is represented by the following formula (2a):
R ² —O— (CO—R ³ —O—) _p —R ⁴ —CR═CH ₂ (2a)
In the formula, R ² , R ³ , R ⁴ and p are as shown in the formula (2),
It can introduce | transduce by the copolymerization using the (meth) acrylate compound represented by these as a monomer.

On the other hand, the repeating unit having an ionic group is, for example, the following formula (3):
—CH ₂ —CRZ— (3)
In the formula, R is a group as defined in the above formula (1), that is, a hydrogen atom or a methyl group,
Z is a cationic group or an anionic group,
It is represented by
The repeating unit having an ionic group as described above has the following formula (3a):
CH ₂ = CRZ (3a)
It introduce | transduces by copolymerization using the cationic or anionic vinyl type compound represented by these.

  In the vinyl compound of the above formula (3a), the cationic compounds include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, diisopropylaminoethyl (meth) acrylate, Amino groups contained in nitrogen-containing compounds such as dibutylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminovinyl sulfide, diethylaminoethyl vinyl ether, vinylbenzyl-N, N'-amine, vinylpyridine, vinylquinoline A quaternized one can be exemplified. This quaternization can be carried out by a known method. For example, a quaternizing agent such as benzyl chloride, benzyl bromide, methyl chloride, methyl bromide is used, and in the presence of an inorganic acid such as hydrochloric acid or sulfuric acid. Can be carried out by reacting with quaternization of the amino group. This quaternization step may be performed after the above nitrogen-containing compound is copolymerized.

  In the vinyl compound of the above formula (3a), anionic compounds include (meth) acrylic acid, α-chloro (meth) acrylic acid, vinyl sulfonic acid, sulfonated ethylene, 2-acrylamido-2-methyl. Propanesulfonic acid, sulfomethyl (meth) acrylate, 2-sulfoethyl (meth) acrylate, 3-sulfoethyl (meth) acrylate, 3-sulfopropyl (meth) acrylate, allylsulfonic acid, 1-phenylvinylsulfonic acid, acid phosphooxyethyl Vinyl monomers having a carboxyl group, sulfonic acid group, phosphoric acid group such as (meth) acrylate, 3-chloro-2-amidophosphooxypropyl (meth) acrylate, acid phosphooxypropyl (meth) acrylate, or the like Alkali metal salt, a Moniumu salt or dimethylamine, triethylamine, organic amine salts such as triethanolamine, tetrabutylphosphonium the like. In the case of a metal salt or an organic salt, the salt may be neutralized after copolymerization.

  In the present invention, among the vinyl monomers of the above formula (3a), particularly preferable ones are cationic ones such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and dipropylaminoethyl (meth) acrylate. A quaternary ammonium salt, an anionic one, is a metal salt of (meth) acrylic acid.

The ionic copolymer having the above-described repeating unit containing an ester chain and a repeating unit having an ionic group includes the (meth) acrylate compound represented by the formula (1a) or (2a) and the formula (3a). Is obtained by copolymerizing by a radical polymerization method according to a conventional method. In such an ionic copolymer, the intrinsic viscosity ηinh is preferably 0.02 or more. That is, when the intrinsic viscosity ηinh is lower than 0.02, it becomes difficult to compatibilize in the surface protective layer formed by the polymerization of the monomer component (A) described above, and the transparency is easily impaired. Also, the antistatic ability tends to decrease.
The intrinsic viscosity ηinh is a value measured at a temperature of 25 ° C. using a solution dissolved in a methyl ethyl ketone / methanol (7/3 volume ratio) mixed solvent at a concentration of 0.5 g / dl.

  In the above ionic copolymer, a repeating unit containing an ester chain (hereinafter sometimes referred to as “ester unit”) and a repeating unit having an ionic group (hereinafter sometimes referred to as “ionic unit”) That is, the weight ratio of the (meth) acrylate compound represented by the formula (1a) or (2a) and the ionic vinyl compound represented by the formula (3a) is 10:90. Or in the range of 90:10. That is, when the amount of the ester unit is larger than the above range, it tends to be difficult to obtain sufficient antistatic ability, and when the amount of the ionic unit is larger than the above range, the polymerization of the monomer component (A). It becomes difficult to make it compatible in the surface protective layer formed by the above, and the transparency may be impaired, or the hardness of the surface protective layer may be lowered and the scratch resistance may be unsatisfactory. Of course, the (meth) acrylate compound of the formula (1a) into which the ester unit is introduced and the (meth) acrylate compound of the formula (2a) can be used in combination, and even in this case, the amount of the ester unit ( It is preferable that the weight ratio of the (meth) acrylate compound of formula (1a) and formula (2a)) and the ionic unit is in the above range.

  An antistatic agent comprising an ionic copolymer having an ester unit and an ionic unit as described above is commercially available, for example, under the name Nikka Taibo from Nippon Kasei Co., Ltd.

  The ionic polymer, that is, the antistatic agent, is blended in an amount of 0.5 to 5 parts by weight per 100 parts by weight of the monomer component (A). If this amount is less than the above range, satisfactory antistatic ability cannot be obtained, and if it is used in a larger amount than the above range, the hardness of the surface protective layer is lowered and the scratch resistance is impaired. In some cases, transparency may be impaired.

<Other ingredients>
In the present invention, the curable resin composition used for forming the surface protective layer contains an antifouling agent in addition to the monomer component (A) and the antistatic agent (B) described above. The antifouling property of the protective layer can be increased. Examples of such an antifouling agent include a polymer of dimethylsiloxane (polydimethylsilicone), a block or graph of dimethylsiloxane and alkylene oxide, a copolymer and a polydimethylsilicone modified with a polyester-modified (meth) acrylate, and the like. Typical examples include silicone compounds such as various fluorine compounds. Such an antifouling agent should be used in such an amount that the characteristics such as scratch resistance (hardness), antistatic ability, transparency and the like of the surface protective layer are not impaired. Usually, the monomer component (A ) It should be used in an amount of 0.001 to 5 parts by weight per 100 parts by weight.

  Moreover, in the curable resin composition, a radical polymerization initiator for polymerizing and curing the monomer component is blended. As such radical polymerization initiator, there are a photopolymerization initiator and a thermal polymerization initiator. Since the curing of the curable resin composition is performed on the transparent resin substrate described above, the transparent resin substrate at the time of polymerization and curing is used. In order to prevent deformation and the like, a photopolymerization initiator is preferably used.

  Suitable examples of the photopolymerization initiator include, but are not limited to, biacetyl, acetophenone, benzophenone, Michler ketone, benzyl, benzoin, benzoin methyl ether, benzoin butyl ether, benzophenol, 4,4′- Dichlorobenzophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzylmethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-isopropylthiookington, bis (2,6-dimethoxybenzoyl-2,4,4-trimethyl-pentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenyl Examples include phosphine oxide, 2,4,6-trimethylbenzoyldiphenyl-phosphine oxide, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, and the like. The photopolymerization initiator is usually blended in an amount of 1 to 10 parts by weight per 100 parts by weight of the monomer component (A).

  Furthermore, in such a curable resin composition, various kinds of additives known per se, such as clay adjusting agents, leveling agents, ultraviolet absorbers, antioxidants, etc., are added so as not to impair the properties of the surface protective layer to be formed. It is also possible to mix | blend in the quantity.

<Manufacture of transparent protective panel>
The protective panel of the present invention provides a transparent resin substrate molded into a predetermined shape by extrusion molding or the like, and after washing and drying the surface of the substrate, the surface of the transparent resin substrate contains the above-described antistatic agent. It is manufactured by applying a curable resin composition and curing the curable resin composition by, for example, ultraviolet irradiation to form a surface protective layer.

  When preparing or applying the curable resin composition, an aromatic hydrocarbon solvent such as toluene or xylene, an ester solvent such as butyl acetate or ethyl acetate, or a cellosolv solvent such as methyl cellosolve or ethyl cellosolve, if necessary. Cellosolve acetate solvents, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and organic solvents such as isopropyl alcohol can be used, and various agents are compatibilized in the monomer component (A) with such organic solvents. Or a coating solution having an appropriate viscosity can be prepared. When the amount of solvent used is limited or when coating without a solvent is required, as described above, the monomer component (A) is a polyfunctional (meta) containing no hydroxyl group. Acrylate (a-3) is used in combination.

  The surface protective layer formed by curing the curable resin composition may usually have a thickness of about 1 to 10 μm.

  After the surface protective layer is formed on one surface of the transparent resin substrate as described above, a mark such as a trademark is appropriately printed on the other surface on which such a surface protective layer is not formed. A protective film such as a film can be attached to the entire surface of the transparent protective panel and shipped in this state. The transparent protective panel is provided for use at a necessary location after the protective film is peeled off.

  The transparent protective panel of the present invention obtained as described above is a single-layer surface protective layer formed on one surface of a transparent resin substrate, which is excellent in transparency and at the same time has high surface hardness and scratch resistance. Mobile phone and digital camera because it has a function as a so-called hard coat layer and has excellent antistatic performance stably for a long time without impairing transparency and scratch resistance. Alternatively, it is particularly effectively used as a protective panel for a liquid crystal display panel in a mobile such as a car navigation system.

The excellent effects of the present invention will be described with reference to the following examples and comparative examples.
In addition, the characteristic of the protection panel obtained in the following examples and comparative examples was evaluated by the following method.

<Transparency>
Judgment was made visually.

<Adhesion>
It was evaluated based on JISK5600 by a cross-cut test using Nichiban cello tape (24 mm width).

<Surface resistance value>
Using a surface resistance measuring instrument SUPER MEGOHMMETER SM-5E manufactured by Toa DKK Co., Ltd., measurement was performed in a measurement environment of 24 ° C. and 40% RH. The smaller the surface resistance value, the better the antistatic ability.

<Surface hardness>
Using a hardness meter C-2210 manufactured by Yoshimitsu Seiki, the pencil hardness was evaluated using Mitsubishi Uni as a pencil. The higher the hardness, the better the scratch resistance.

<Abrasion resistance (SW0000)>
Using a tester BONSTER No. 0000 manufactured by Nippon Steel Wool Co., Ltd., the presence or absence of scratches was visually determined when reciprocating 150 times at a pressure of 500 g / cm ² .

<Contamination resistance>
The marks drawn on the surface using Pentel's fine magic MS50 were evaluated by wiping with a tissue paper made of Napier.

  In the following examples and comparative examples, the following were used as components in the curable resin composition for forming the surface protective layer.

Monomer A1 (corresponding to monomer (a-1)):
15-functional urethane acrylate UN-3320HS manufactured by Negami Kogyo (urethane acrylate solid content 95%)
Monomer A2 (corresponding to monomer (a-1)):
9-functional urethane acrylate, manufactured by Negami Kogyo UN-901T (urethane acrylate solid content 80%)
Monomer A ′:
Hexafunctional urethane acrylate, manufactured by Negami Kogyo (solid content of urethane acrylate 100%)

Monomer B1 (corresponding to monomer (a-2)):
Pentaerythritol triacrylate ATMM3LMN manufactured by Shin-Nakamura Chemical Co., Ltd.

Monomer C1 (corresponding to monomer (a-3)):
Dipentaerythritol hexaacrylate

Antistatic agent:
Nikka Taibo manufactured by Nippon Kasei Co., Ltd. An ionic copolymer obtained by copolymerization of a methacrylic compound represented by the following formula and an ionic vinyl compound: a methacrylic compound;
_{^{R 2 -O- (CO-R 3}} -O-) p -R 4 -C (CH 3) = CH 2
R ² : an alkyl group
R ³ : —CH ₂ CH ₂ CH (CH ₃ ) CH ₂ —
R ^4: -CONH-ph-
Ionic vinyl compounds;
Quaternary ammonium salt of dimethylaminoethyl (meth) acrylate copolymerization ratio; 1: 1
Intrinsic viscosity ηinh; 0.15

Antifouling agent 1:
BYK-UV3570 made by Big Chemie
70% PONPGDA (polyolefin-modified-2-neopentylglycol diacrylate) solution of polydimethylsiloxane having polyester-modified acrylic group antifouling agent 2:
DMS-U22 manufactured by Amax Co., Ltd.
Acryloxypropyl-terminated polydimethylsiloxane antifouling agent 3:
X-22-22426 made by Shin-Etsu Silicone
One-end methacryl-modified silicone oil

UV radical polymerization initiator:
1-hydroxycyclohexyl phenyl ketone

Organic solvent:
1: 1 mixed solvent of toluene and propylene glycol monomethyl ether

  In the following examples, the amounts of the monomers A1 and A2 are shown by the amount of urethane acrylate solids.

Example 1
A coating solution for the curable resin composition was prepared according to the following formulation. (Monomer A1
Monomer A1; 100 parts by weight (solid content)
Monomer B1; 42.90 parts by weight Antistatic agent; 2.10 parts by weight per 100 parts by weight of total monomer Antifouling agent 2; 0.43 parts by weight per 100 parts by weight of total amount of monomer UV radical polymerization initiator;
5.0 parts by weight per 100 parts by weight of total monomer Organic solvent; 140 parts by weight per 100 parts by weight of total monomer

The above coating solution was coated on an acrylic plate (Acrylite L manufactured by Mitsubishi Rayon), cured by ultraviolet irradiation, and a protective panel was produced by forming a surface protective layer having a thickness of 5 μm.
The composition of the coating solution used is shown in Table 1, and various properties of the obtained protective panel were evaluated. The results are shown in Table 2.

(Example 2)
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of the curable resin composition was prepared according to the following formulation. The composition of the coating liquid used is shown in Table 1, and the obtained protective panel The characteristics were evaluated and the results are shown in Table 2.
Monomer A1; 100 parts by weight (solid content)
Monomer B1; 0.1 parts by weight Antistatic agent; 2.0 parts by weight per 100 parts by weight of total monomer Antifouling agent 1; 0.31 parts by weight per 100 parts by weight of total amount of monomer UV radical polymerization initiator; 5.0 parts by weight per part by weight Organic solvent; 200 parts by weight per 100 parts by weight of total monomer

(Example 3)
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of the curable resin composition was prepared according to the following formulation. The composition of the coating liquid used is shown in Table 1, and the obtained protective panel The characteristics were evaluated and the results are shown in Table 2.
Monomer A1; 100 parts by weight (solid content)
Monomer B1; 20.0 parts by weight Antistatic agent; 5.0 parts by weight per 100 parts by weight of total monomer Antifouling agent 2; 0.52 parts by weight per 100 parts by weight of total monomer A UV radical polymerization initiator; 5.0 parts by weight per part by weight of organic solvent; 167 parts by weight per 100 parts by weight of total monomer

Example 4
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of the curable resin composition was prepared according to the following formulation. The composition of the coating liquid used is shown in Table 1, and the obtained protective panel The characteristics were evaluated and the results are shown in Table 2.
Monomer A1; 100 parts by weight (solid content)
Monomer B1; 20 parts by weight Antistatic agent; 1.0 part by weight per 100 parts by weight of total monomer Antifouling agent 2; 0.52 parts by weight per 100 parts by weight of total amount of monomer UV radical polymerization initiator; 100 parts by weight of total amount of monomer 5.0 parts by weight of organic solvent; 167 parts by weight per 100 parts by weight of total monomer

(Example 5)
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of the curable resin composition was prepared according to the following formulation. The composition of the coating liquid used is shown in Table 1, and the obtained protective panel The characteristics were evaluated and the results are shown in Table 2.
Monomer A2: 100 parts by weight (solid content)
Monomer B1; 10 parts by weight Monomer C1; 10 parts by weight Antistatic agent; 3.3 parts by weight per 100 parts by weight of total monomer Antifouling agent 3; 1.37 parts by weight per 100 parts by weight of total amount of monomer UV radical polymerization initiator ; 5.2 parts by weight per 100 parts by weight of total monomer Organic solvent; 167 parts by weight per 100 parts by weight of total monomer

(Example 6)
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of a curable resin composition was prepared according to the following formulation, and this was coated on a polycarbonate single-sided acrylic resin laminate, and the composition of the coating liquid used was The characteristics of the protective panel obtained are shown in Table 1 and evaluated, and the results are shown in Table 2.
Monomer A1; 100 parts by weight (solid content)
Monomer B1; 0.1 parts by weight Antistatic agent; 2.0 parts by weight per 100 parts by weight of total monomer Antifouling agent 1; 0.31 parts by weight per 100 parts by weight of total amount of monomer UV radical polymerization initiator; 5.0 parts by weight per part by weight Organic solvent; 200 parts by weight per 100 parts by weight of total monomer

(Comparative Example 1)
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of the curable resin composition was prepared according to the following formulation. The composition of the coating liquid used is shown in Table 1, and the obtained protective panel The characteristics were evaluated and the results are shown in Table 2.
Monomer A1; 100 parts by weight (solid content)
Monomer B1; 2.0 parts by weight Antistatic agent; 10 parts by weight per 100 parts by weight of total monomer Antifouling agent 1; 0.30 parts by weight per 100 parts by weight of total amount of monomer UV radical polymerization initiator; 100 parts by weight of total amount of monomers 5.0 parts by weight Organic solvent; 196 parts by weight per 100 parts by weight of total monomer

(Comparative Example 2)
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of the curable resin composition was prepared according to the following formulation. The composition of the coating liquid used is shown in Table 1, and the obtained protective panel The characteristics were evaluated and the results are shown in Table 2.
Monomer A1; 100 parts by weight (solid content)
Monomer B1; 2.0 parts by weight Antistatic agent; 0.10 parts by weight per 100 parts by weight of the total amount of monomers Antifouling agent 1; 0.30 parts by weight per 100 parts by weight of the total amount of monomers UV radical polymerization initiator; 5.0 parts by weight per 100 parts by weight Organic solvent; 196 parts by weight per 100 parts by weight of total monomer

(Comparative Example 3)
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of the curable resin composition was prepared according to the following formulation. The composition of the coating liquid used is shown in Table 1, and the obtained protective panel The characteristics were evaluated and the results are shown in Table 2.
Monomer A1; 100 parts by weight (solid content)
Monomer B1: 100 parts by weight Antistatic agent: 0.50 part by weight per 100 parts by weight of the total amount of monomers Antifouling agent 1; 0.16 parts by weight per 100 parts by weight of the total amount of monomers UV radical polymerization initiator; 5.0 parts by weight per part organic solvent; 200 parts by weight per 100 parts by weight of total monomer

(Comparative Example 4)
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of the curable resin composition was prepared according to the following formulation. The composition of the coating liquid used is shown in Table 1, and the obtained protective panel The characteristics were evaluated and the results are shown in Table 2.
Monomer A1; 100 parts by weight (solid content)
Antistatic agent: 1.0 part by weight per 100 parts by weight of monomer Antifouling agent 2: 0.62 parts by weight per 100 parts by weight of monomer UV radical polymerization initiator: 5.0 parts by weight per 100 parts by weight of monomer Part organic solvent; 200 parts by weight per 100 parts by weight of total monomer

(Comparative Example 5)
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of the curable resin composition was prepared according to the following formulation. The composition of the coating liquid used is shown in Table 1, and the obtained protective panel The characteristics were evaluated and the results are shown in Table 2.
Monomer A1; 100 parts by weight (solid content)
Monomer B1; 2.0 parts by weight Antistatic agent; 0.98 parts by weight Ultraviolet radical polymerization initiator; 5.0 parts by weight Organic solvent; 196 parts by weight

(Comparative Example 6)
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of the curable resin composition was prepared according to the following formulation. The composition of the coating liquid used is shown in Table 1, and the obtained protective panel The characteristics were evaluated and the results are shown in Table 2.
Monomer A1; 100 parts by weight (solid content)
Monomer B1; 2.0 parts by weight Antistatic agent; 0.98 parts by weight per 100 parts by weight of total monomer Antifouling agent 1; 11.8 parts by weight per 100 parts by weight of total amount of monomer UV radical polymerization initiator; 5.0 parts by weight of organic solvent per part by weight; 196 parts by weight

(Comparative Example 7)
A protective panel was prepared in the same manner as in Example 1 except that a coating liquid of the curable resin composition was prepared according to the following formulation. The composition of the coating liquid used is shown in Table 1, and the obtained protective panel The characteristics were evaluated and the results are shown in Table 2.
Monomer A ′; 100 parts by weight Monomer B1; 2.0 parts by weight Antistatic agent; 0.98 parts by weight per 100 parts by weight of total monomer Antifouling agent 2; 0.61 parts by weight per 100 parts by weight of total amount of monomers Polymerization initiator: 5.0 parts by weight per 100 parts by weight of the total amount of monomers Organic solvent: 196 parts by weight

Claims (5)

In a transparent protective panel comprising a transparent resin substrate and a surface protective layer provided on the substrate,
The surface protective layer is obtained by curing an antistatic agent-containing curable resin composition,
The antistatic agent-containing curable composition contains the monomer component (A) and 0.5 to 5 parts by weight of the antistatic agent (B) per 100 parts by weight of the monomer component (A).
The monomer component (A) has the following composition:
(A-1) 100 folds of urethane acrylate containing 9 or more radical polymerizable functional groups
Amount part;
(A-2) Multifunctional (meth) a having a hydroxyl group and three or more radical polymerizable functional groups
0.1 to 42.9 parts by weight of chlorate;
And having
The antistatic agent (B) comprises an ionic copolymer having a repeating unit containing an ester chain and a repeating unit having an ionic group. The repeating unit containing an ester chain in the ionic copolymer has the following formula (1):
_{- (CRX-CH 2) -} ... (1)
In the formula, R is a hydrogen atom or a methyl group,
X is the following formula:
HO— (R ¹ —COO—) _n — (CH ₂ ) _m —OOC—
(Where R ¹ is a divalent aliphatic hydrocarbon group, n is 2 to 200, and m is
An integer from 1 to 8,)
A monovalent group represented by:
Or the following formula (2):
_{- (CRY-CH 2) -} ... (2)
In the formula, R is a group as defined in the formula (1),
Y is the following formula:
R ² —O— (CO—R ³ —O—) _p —R ⁴ —
Here, p is an integer of 2 to 200, and R ² is an alkyl group having 1 to 20 carbon atoms.
Or an aralkyl group, R ³ is a divalent aliphatic hydrocarbon group,
_{-CONH-ph -, - CONH-} C (CH 3) 2 -ph-,
_{-CONHCO -, - CONH- (CH 2} ) q -OOC-, or
-CO- (where ph is an optionally substituted phenylene group)
Q is an integer of 1 to 10),
A monovalent group represented by:
The transparent protection panel of Claim 1 represented by these. The repeating unit having an ionic group in the ionic copolymer is represented by the following formula (3):
—CH ₂ —CRZ— (3)
In the formula, R is as defined in the formula (1),
Z is an anionic group or a cationic group,
The transparent protection panel of Claim 2 represented by these.   The ionic copolymer has an intrinsic viscosity ηinh of 0.02 or more, and contains a repeating unit containing an ester chain and a repeating unit having an ionic group in a weight ratio of 10:90 to 90:10. The transparent protective panel according to any one of claims 1 to 3.   4. The transparent protective panel according to claim 1, wherein the transparent resin substrate is a polycarbonate resin substrate, an acrylic resin substrate, or a laminate having an acrylic resin layer formed on at least one surface of a polycarbonate resin layer.