JPH04270772A - Resin composition for hard-coating of optical disk - Google Patents

Abstract

PURPOSE:To provide a UV-curable coating material having antistaticity as well as hardness. CONSTITUTION:The objective resin composition contains (A) a phosphoric acid ester having acryloyl group or methacryloyl group and (B) an organic compound having >=2 active ethylene groups in one molecule. An optical disk may cause the error in reading, writing and erasing by the adhesion of dust in the environment and the flaw on the disk. The adhesion of dust can be prevented by the coating material. At the same time, the damage of the disk in handling can be prevented and the generation of the above errors can be suppressed by the application of a coating film having high surface hardness.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a resin composition for hard coating of optical disks, which has both antistatic function and scratch resistance, and more specifically, it relates to a resin composition for hard coating of optical disks, which has both antistatic function and scratch resistance. The present invention relates to a resin composition for a hard coat that has the effect of preventing recording errors on optical discs due to the adhesion of dust due to the environment and scratches during handling.

0002

2. Description of the Related Art The basic structure of an optical disk is, for example, as shown in FIG.
A guide groove for configuring recording is provided on one surface of the substrate of MA, PC), and then a recording film, a reflective film, etc. are laminated. There is no particular problem with the other side of the substrate when glass is used as the substrate, but when using the above-mentioned organic polymers, especially PC, as the substrate, the other side of the substrate is soft by itself, so it is necessary to prevent scratches during handling. It is coated with a so-called hard coat to provide scratch resistance.

However, another drawback of optical discs is that their recording performance deteriorates due to the adhesion of dust in the environment. In other words, the principle of the recording operation of an optical disc is that light is transmitted from the substrate side opposite to the recording film, so if dust adheres to that surface, the light will not pass through or it will not be possible to obtain a sufficient amount of light. , an error will occur in the recording operation.

[0004] Therefore, in order to remove this adhered dust, a method has been considered in which a brush is attached to the drive and the dust is brushed away using the rotation of the disk inserted in the drive, but it is difficult to remove the dust to a certain extent. Although this method is effective in the case of dust, if the disk is rubbed below a certain level, static electricity will be generated and the dust will be attracted to the disk.

[0005] To prevent this, it is necessary to make the surface of the disk have both scratch resistance and antistatic performance.

[0006] Among these methods, as a method for obtaining antistatic properties,
For example, a method is known in which a surfactant is applied to the surface. Although this method provides good initial antistatic performance, it is difficult to scrub the surface with a brush to remove dust adhering to the surface. In this case, there was a problem in that the components fell off and the performance deteriorated in a short period of time.

[0007] Therefore, a method has been proposed in which an antistatic agent and a binder component react to form an integral film. for example,
JP-A-59-230057 describes a method for introducing SO3M groups into a comb-shaped graft polymer; JP-A-61-2
61344 describes a method using an alkali metal salt and a thermoplastic resin containing polyalkylene glycol;
3-54466 and JP-A-63-54467 disclose a thermoplastic resin composition using a resin composition having a quaternary ammonium salt and a vinyl or vinylidene monomer copolymerizable with the resin composition. Method used; JP-A-62-207
No. 353 describes a method of introducing a monomer having both an ionic electrolyte group and an ethylenically unsaturated group into a copolymer; JP-A-61-73709 and JP-A-61-78807.
JP-A-57-65761 proposes a method of using a polymerizable acidic phosphate ester and a photosensitive resin composition in combination.

However, the above-mentioned Japanese Patent Application Laid-Open No. 59-2300
No. 57, JP-A No. 61-261344, JP-A No. 63-54466, and JP-A No. 63-54467, even if antistatic performance can be exhibited, the constituent resin composition is thermoplastic. Since it is a resin, sufficient scratch resistance cannot be obtained. Also, JP-A-62-207353
In JP-A-61-73709 and JP-A-61-78807, the amount of the component having an antistatic function used is as small as about 10%, so long-term performance stability is lacking. Furthermore, in Japanese Patent Application Laid-open No. 57-65761,
The amount of polymerizable phosphate ester compound used is 0.05 to 2
Although it is used in an amount of about 0%, a polyethylene glycol condensation type surfactant is an essential component in order to exhibit its antistatic performance. Therefore, when a film is formed using such a composition, the surfactant is likely to be eluted due to dew condensation, making it impossible to exhibit its performance. In any case, in these proposals, the amount of polymerizable phosphate ester used had to be kept to a small amount from the viewpoint of ensuring coating film hardness and breathing.

[0009]

OBJECTS TO BE SOLVED BY THE INVENTION The problem to be solved by the present invention is to provide a hardware that provides sufficient hardness and low surface resistance, prevents scratches and adhesion of environmental dust, and prevents operational errors of optical discs. An object of the present invention is to provide an ultraviolet curable resin composition capable of forming a coating layer.

0010

[Means for Solving the Problems] As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that it is possible to use a polymerizable phosphate ester compound in a larger amount than in the prior art. As a result, it was discovered that sufficient performance could be exhibited, and the present invention was completed. That is, in order to solve the above-mentioned problems, the present invention provides (1) an organic compound having two or more UV-curable active ethylene groups in the molecule, and (2) the general formula (I).

[0011]

[Chemical formula 3]

(wherein R represents hydrogen or a methyl group,
n represents 1 or 2. ) Compounds represented by and general formula (II)

[0013]

[C4]

(wherein R represents hydrogen or a methyl group,
m represents an integer of 1 to 8, and n represents 1 or 2. )
Provided is a resin composition for a hard coat of an optical disk, which contains a phosphoric acid compound having an acryloyl group or a methacryloyl group selected from the group consisting of the compounds represented by the following.

[0015] The polymerizable phosphate ester used in the present invention is
Compounds represented by the above general formulas (I) and (II), in which free OH bonded to the phosphoric acid group is present in the structure.
The group is a compound having at least one group. Therefore,
General formula (III)

[0016]

[C5]

(In the formula, R represents hydrogen or a methyl group.) If there is no free OH group bonded to the phosphoric acid group, no effect can be exerted at all.

As a commercially available product of the polymerizable phosphate ester used in the present invention, for example, "AR-2" manufactured by Daihachi Chemical Industry Co., Ltd.
00”, “ARL-200”, “MR-200”, “M
RL-200'' and the like. These compounds are 2
It is also possible to use more than one species in combination.

Examples of organic compounds containing two or more active ethylene groups in one molecule used in the present invention include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,
3 - Poly(meth)acrylates such as butylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, trimethylolpropane, glycerin, and pentaerythritol; 2 or more moles of ethylene oxide or propylene oxide added to 1 mole of neopentyl glycol di(meth)acrylate of diol obtained by
Triol di- or tri(meth)acrylate obtained by adding 3 moles or more of ethylene oxide or propylene oxide to 1 mole of diol; diol di(meth)acrylate obtained by adding 2 mole or more of ethylene oxide or propylene oxide to 1 mole of bisphenol A; Meth)acrylate; poly(meth)acrylate of dipentaerythritol, etc. can be mentioned.

Among these, preferred are those whose coating film hardness is 3H or more in terms of pencil hardness when polymerized in the presence of a photopolymerization initiator.

The usage ratio of the polymerizable phosphate ester compound in the hard coat resin composition for optical discs of the present invention is 6
A range of 5 to 95% by weight is preferred. When the proportion of the polymerizable phosphoric acid ester compound used is less than 65% by weight, as is clear from Figure 2, the surface resistance value of the coating film when the mixture is applied and cured with ultraviolet rays becomes less antistatic. If it is more than the required 1010 Ω/□, and if the usage ratio is more than 95% by weight, the hardness of the coating film will be H or less in terms of pencil hardness, making it impossible to obtain the desired scratch resistance, which is not preferable.

When photopolymerizing the hard coat resin composition for optical disks of the present invention, it is preferable to use a photopolymerization initiator together.

Examples of photopolymerization initiators include 2-hydroxy-2-methyl-1-phenylpropan-1-one ("Darocur 1173" manufactured by Merck & Co.), 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba-Geigy) "Irgacure 184"), 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1
-one (“Darocur 1116” manufactured by Merck & Co.), benzyl dimethyl ketal (“Irgacure 651” manufactured by Ciba Geigy), 2-methyl-1-[4-(methylthio)
phenyl]-2-morpholinopropanone-1 (“Irgacure 907” manufactured by Ciba Geigy), 2,4-diethylthioxanthone (“Kayacure DET” manufactured by Nippon Kayaku Co., Ltd.)
X") and ethyl p-dimethylaminobenzoate ("Kayacure-EPA" manufactured by Nippon Kayaku Co., Ltd.), isopropylthioxanthone ("Cantacure ITX" manufactured by Ward Prekinsop) and ethyl p-dimethylaminobenzoate Examples include mixtures of the following.

When a photopolymerization initiator is used in combination, the proportion used is determined by the conditions of the ultraviolet irradiation machine used for curing, but in general, 3% of the hard coat resin composition for optical discs is used.
A range of 7% by weight is preferred.

In addition, a polymerization inhibitor, an antifoaming agent, a leveling agent, a solvent, a polymerizable diluent, etc. may be added to the hard coat resin composition for optical disks of the present invention.

[0026] In addition, for curing, it is also possible to use an electron beam in addition to ultraviolet irradiation, and the polymerization initiator can be
For example, if a peroxide such as benzoyl peroxide is used, it is also possible to utilize a thermosetting reaction.

[0027]

EXAMPLES The present invention will be explained in more detail below using examples. In addition, in the examples, "part" represents "weight %".

(Example 1) "ARL-200" manufactured by Daihachi Chemical Industry Co., Ltd. was used as a polymerizable phosphoric acid ester, and "M-200" manufactured by Toagosei Chemical Industry Co., Ltd. was used as an active ethylene-containing compound.
215'' respectively, 30 copies: 70 copies, 50 copies: 50 copies, 7
0 parts: 30 parts, 90 parts: 10 parts, 95 parts: 5 parts and 10
Irgacure 651 manufactured by Nippon Ciba Geigy Co., Ltd. was used as a photopolymerization initiator at a ratio of 0 parts: 0 parts (comparative example).
'' were mixed to prepare hard coat resin compositions for optical discs.

[0029] A hard coat resin composition for optical discs, using a polycarbonate (hereinafter referred to as PC) used for optical discs as a substrate, obtained using a spin coater so that the dry coating thickness on the side opposite to the grooves of the substrate is 4μ. After each coating was applied, irradiation was performed for 5 seconds using a metal halide lamp of 410 mW/cm2 to obtain a cured film.

Next, this cured film was subjected to a pencil hardness test, and the surface resistance value (Ω/□) was measured, and the results are shown in FIG. In the figure, HB, H, etc. indicate pencil hardness.

(Example 2) In Example 1, "MR-2" manufactured by Daihachi Kagaku Kogyo Co., Ltd. was used as the polymerizable phosphate ester.
A hard coat resin composition for optical discs was used, which consisted of 70 parts of "00", 30 parts of "M-400" manufactured by Toagosei Kagaku Kogyo Co., Ltd. as an active ethylene-containing compound, and 5 parts of "Irgacure 651" as a photopolymerization initiator. A cured film was obtained in the same manner as in Example 1 except for this.

[0032] This cured film was subjected to a pencil hardness test in the same manner as in Example 1, and the surface resistance value was measured. The results are shown in Table 1.

(Example 3) In Example 1, "AR-2" manufactured by Daihachi Kagaku Kogyo Co., Ltd. was used as the polymerizable phosphate ester.
00" 70 parts, "M-4" as an active ethylene-containing compound
00'' and 30 parts of ``Irgacure 6'' as a photopolymerization initiator.
A cured film was obtained in the same manner as in Example 1, except that a hard coat resin composition for optical disks consisting of 5 parts of "51" was used.

[0034] This cured film was subjected to a pencil hardness test in the same manner as in Example 1, and the surface resistance value was measured. The results are shown in Table 1.

(Example 4) In Example 1, "MRL-" manufactured by Daihachi Chemical Industry Co., Ltd. was used as the polymerizable phosphate ester.
200” 70 parts, “M-” as an active ethylene-containing compound
A cured film was obtained in the same manner as in Example 1, except that a hard coat resin composition for an optical disk was used, which consisted of 30 parts of "Irgacure 651" as a photopolymerization initiator and 30 parts of "Irgacure 651" as a photopolymerization initiator.

[0036] This cured film was subjected to a pencil hardness test in the same manner as in Example 1, and the surface resistance value was measured. The results are shown in Table 1.

(Example 5) In Example 1, 35 parts of "ARL-200" and "MR
35 parts of ``-200'', 35 parts of ``M
A cured film was obtained in the same manner as in Example 1, except that a hard coat resin composition for an optical disk was used, which consisted of 30 parts of "-400" and 5 parts of "Irgacure 651" as a photopolymerization initiator.

[0038] This cured film was subjected to a pencil hardness test in the same manner as in Example 1, and the surface resistance value was measured. The results are shown in Table 1.

(Comparative Example 1) In Example 1, "MR-2" manufactured by Daihachi Chemical Industry Co., Ltd. was used as the polymerizable phosphate ester.
60” 70 parts, “M-4” as an active ethylene-containing compound
00'' and 30 parts of ``Irgacure 6'' as a photopolymerization initiator.
A cured film was obtained in the same manner as in Example 1, except that a hard coat resin composition for optical disks consisting of 5 parts of ``51'' was used.

[0040] This cured film was subjected to a pencil hardness test in the same manner as in Example 1, and the surface resistance value was measured. The results are shown in Table 1.

(Comparative Example 2) In Example 1, "AR-2" manufactured by Daihachi Chemical Industry Co., Ltd. was used as the polymerizable phosphoric ester.
60” 70 parts, “M-4” as an active ethylene-containing compound
00'' and 30 parts of ``Irgacure 6'' as a photopolymerization initiator.
A cured film was obtained in the same manner as in Example 1, except that a hard coat resin composition for optical disks consisting of 5 parts of "51" was used.

[0042] This cured film was subjected to a pencil hardness test in the same manner as in Example 1, and the surface resistance value was measured. The results are shown in Table 1.

[0043]

[Table 1]

[0044]

Effects of the Invention: According to the hard coat resin composition for optical discs of the present invention, a hard coat that has both antistatic performance and surface hardness can be formed on optical discs, thereby preventing dust from adhering to them and preventing scratches during handling. This makes it possible to prevent errors in the recording operation of optical discs.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the basic configuration of an optical disc.

[Explanation of symbols]

1 Hard coat layer 2 Board 3 Dielectric material 4 Recording film layer 5 Reflective film layer 6 Overcoat layer

FIG. 2 is a chart showing the relationship between the content of polymerizable phosphate ester "ARL-200" contained in the resin composition forming the hard coat layer, and the surface resistance value and pencil hardness of the hard coat layer. be.

Claims (4)

[Claims] Claim 1: (1) an organic compound having two or more UV-curable active ethylene groups in the molecule; and (2) general formula (I): , n is 1 or 2
represents. ) and general formula (II) [
An acryloyl group or a methacryloyl group selected from the group consisting of compounds represented by the following formula: (wherein R represents hydrogen or a methyl group, m represents an integer of 1 to 8, and n represents 1 or 2) 1. A resin composition for a hard coat of an optical disc, comprising a phosphoric acid compound having the following properties. Claim 2: The content of the phosphoric acid compound having an acryloyl group or a methacryloyl group is 65 to 65% in the total composition.
The resin composition for a hard coat of an optical disk according to claim 1, wherein the resin composition is in the range of 95% by weight. 3. Claim 1 or 2 in which two or more phosphoric acid compounds having an acryloyl group or a methacryloyl group selected from the group consisting of a compound represented by general formula (I) and a compound represented by general formula (II) are used. The resin composition for a hard coat of an optical disc as described above. 4. The resin composition for a hard coat of an optical disk according to claim 1 or 2, which contains a photopolymerization initiator.