JP3179172B2 - Photocurable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Background of the Invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocurable composition which is cured by irradiation with active energy rays such as ultraviolet rays.
More specifically, the present invention relates to a casting polymerization composition suitable for manufacturing optical components such as lenses, prisms, mirrors, and optical disks.

[0002]

2. Description of the Related Art A method of manufacturing a plastic lens by irradiating a photocurable resin with ultraviolet rays such as a mercury lamp as an active energy ray has been proposed (Japanese Patent Laid-Open No. Sho 6).
1-194401, JP-A-63-207632). According to this method, there is an advantage of short-time curing by ultraviolet irradiation, but at present, the internal homogeneity and surface transfer accuracy are not sufficient, and generally, the transparency and hue of a lens obtained by ultraviolet curing are It appears to be inferior to polymers of polymethyl methacrylate, polycarbonate, diethylene glycol bisallyl carbonate, and the like. Therefore, it cannot be said that the lens obtained by such a conventional method using ultraviolet rays has many practical problems.

[Summary of the Invention]

SUMMARY OF THE INVENTION The present invention has been made in order to improve the above-mentioned drawbacks of the conventional method, and has excellent mass productivity, internal uniformity, and good surface transfer accuracy.
An object of the present invention is to provide a composition for injection polymerization suitable for producing an optical component having an ultraviolet cut property and excellent in transparency and hue.

[0004]

The object of the present invention is to provide a photocurable composition comprising a photopolymerizable monomer containing a specific photopolymerization initiator and a specific ultraviolet absorber in a specific ratio. What we are trying to achieve.

<Summary> That is, the photocurable composition of the present invention comprises the following components (1) to (5):
(However, components (1) to (3)
Is 100 parts by weight).

Component (1): 50 to 99 parts by weight of a polyfunctional photopolymerizable (meth) acrylate monomer Component (2): From compounds represented by the following formulas [I], [II] and [III] 1 to 30 parts by weight of a mercapto compound selected from the group consisting of [Wherein, R ¹ represents —CH ₂ — or —CH ₂ CH ₂ —, and R ² has 2 to 15 carbon atoms that may contain ether oxygen.
And a represents an integer of 2 to 6. A plurality of groups may be the same or different. ]

[0007]

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[0008] _c- (where b and c each represent an integer of 1 to 8, d represents an integer of 0 to 2. A plurality of groups may be the same or different.)

[0009]

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[Wherein R ³ and R ⁴ each represent an alkylene group having 1 to 3 carbon atoms, and m and n each represent 0
Or 1, p represents 1 or 2. A plurality of groups may be the same or different. Component (3): 1 to 49 parts by weight of a styrene monomer represented by the following formula [IV]

[0011]

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[In the formula, R ⁵ represents a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, and q represents 0 or 1.
Represents an integer of from 5 to 5. A plurality of groups may be the same or different. Component (4): 0.01 to 0.3 parts by weight of a photopolymerization initiator compound represented by the following formula [V]

[0013]

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[In the formula, R ⁶ represents a phenyl group or a phenoxy group, and r and s each represent an integer of 0 or 1 (provided that r + s ≠ 0). Multiple groups are
They may be the same or different. Component (5): 0.01 to 0.2 parts by weight of an ultraviolet absorber selected from a benzophenone-based ultraviolet absorber and a benzotriazole-based ultraviolet absorber

<Effects> The photocurable composition according to the present invention can be mass-produced by photocuring a polymer having excellent internal homogeneity, surface transfer accuracy, ultraviolet cut properties, transparency and hue. Can be manufactured well.

[Specific description of the invention] The photocurable composition according to the present invention comprises components (1) to (5). Here, "comprising" includes a small amount of auxiliary components (details described later) in addition to the components shown, that is, components (1) to (5), as long as the gist of the present invention is not impaired. It means that it is OK.

<Component (1): Multifunctional photopolymerizable (meth) acrylate monomer> The main component of the photocurable composition according to the present invention is a polyfunctional photopolymerizable (meth) acrylate monomer. Here, first, “polyfunctional photopolymerizable” means having a plurality of photopolymerizable ethylenically unsaturated bonds. And "(meth) acrylate monomer"
Is a general term for acrylate monomers and methacrylate monomers.

Accordingly, "(meth) acrylate monomers" defined as having "polyfunctional photopolymerizability"
Is a (meth) acrylate monomer having photopolymerizability, in which the photopolymerizable ethylenically unsaturated bond is derived from a (meth) acryl group, specifically, for example, Bis (meth) acrylate or tris (meth) acrylate.

One specific example of a suitable bis (meth) acrylate is bis (meth) acrylate of bisphenol A or bisphenol F represented by the following formula or bis (meth) acrylate of the corresponding hydrogenated bisphenol nucleus. .

[0020]

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(Wherein, R ⁷ represents a hydrogen atom or a methyl group, R ⁸ represents an alkylene group having 2 to 3 carbon atoms, Y represents a hydrogen atom, a chlorine atom or a bromine atom, and i and j each represent 0 or an integer of 1 to 6, i and j
Is 0 to 6. R ⁹ represents a hydrogen atom or a methyl group. A plurality of groups may be the same or different. )

Another suitable bis (meth) acrylate monomer is an alkyleneoxybis (meth) acrylate represented by the following formula:
Acrylate.

Wherein R ¹⁰ represents a hydrogen atom or a methyl group; R ¹¹ represents an alkylene group having 2 to 15 carbon atoms;
Represents an integer of 1 to 14. A plurality of groups may be the same or different. )

Still other suitable polyfunctional photopolymerizable (meth)
The acrylate monomer is tris (meth) acrylate of a trihydroxy compound. Specifically, for example, trimethylolpropane = tri (meth) acrylate, trimethylolethane = tri (meth) acrylate, and pentaerythritol = tri (meth) acrylate Examples thereof include (meth) acrylate.

Particularly preferred polyfunctional photocurable polymerizable (meth)
Specific examples of acrylates include 2,2-bis (4-methacryloyloxyphenyl) propane, 2,2-bis (4-methacryloyloxy-3,5-dibromophenyl) propane, and 2,2-bis (4- Methacryloyloxyethoxyphenyl) propane, 2,2-bis (4-methacryloyloxyethoxy-3,5-dibromophenyl) propane, 2,2-bis (4-methacryloyloxydiethoxyphenyl) propane, 2,2-bis (4-
(Methacryloyloxyethoxy-3,5-dibromophenyl) propane, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, trimethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 2,2 -Bis (4-methacryloyloxycyclohexyl) propane and the like.

<Component (2): Mercapto compound> The mercapto compound of the component (2) is a compound represented by each of the following formulas [I] to [III]. The mercapto compound as the component (2) can be used in each group and / or between each group. [Wherein, R ¹ represents —CH ₂ — or —CH ₂ CH ₂ —, and R ² has 2 to 15 carbon atoms that may contain ether oxygen.
And a represents an integer of 2 to 6. A plurality of groups may be the same or different. ]

[0027]

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[0028] ) _C- (where b and c each represent an integer of 1 to 8, d represents an integer of 0 to 2. A plurality of groups may be the same or different.)

[0029]

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[Wherein R ³ and R ⁴ each represent an alkylene group having 1 to 3 carbon atoms, and m and n each represent 0
Or 1, p represents 1 or 2. A plurality of groups may be the same or different. ]

The mercapto compound represented by the formula [I] is
It is a divalent to hexavalent thioglycolic acid or thiopropionate. Specific examples of the compound of the formula [I] include, for example, pentaerythritol tetrakis (β-thiopropionate), pentaerythritol tetrakis (thioglycolate), trimethylolpropane tris (β
-Thiopropionate), trimethylolpropane tris (thioglycolate), diethylene glycol bis (β-thiopropionate), diethylene glycol bis (thioglycolate), triethylene glycol bis (β-thiopropionate) Examples include ethylene glycol bis (thioglycolate), dipentaerythritol hexakis (β-thiopropionate), dipentaerythritol hexakis (thioglycolate), and the like.

Specific examples of the compound of the formula [II] include, for example, tris [2- (β-thiopropionyloxy) ethyl] triisocyanurate, tris (2-thioglyconyloxyethyl) isocyanurate, tris [2 -
(Β-thiopropionyloxyethoxy) ethyl] triisocyanurate, tris (2-thioglyconyloxyethoxyethyl) triisocyanurate, tris [3-
(Β-thiopropionyloxy) propyl] triisocyanurate, tris (3-thioglyconyloxypropyl) triisocyanurate and the like.

Specific examples of the compound of the formula [III] include, for example, benzenedimercaptan, xylylenedimercaptan, 4,4'-dimercaptodiphenylsulfide and the like.

<Component (3): Styrene monomer> Formula [IV]
Specific examples of the compound represented by are styrene, α-methylstyrene, chlorostyrene, dichlorostyrene, bromostyrene, dibromostyrene, pentabromostyrene and the like.

<Composition (Part 1)> These polyfunctional (meta)
Acrylate (component (1)), a compound represented by general formula [I], [II],
Alternatively, the composition ratio of the mercapto compound (component (2)) represented by [III] is 1 to 30 parts by weight, preferably 60 to 9 parts by weight, with respect to 50 to 98 parts by weight of the former.
The latter is in the range of 1 to 20 parts by weight relative to 0 parts by weight. However, the “parts by weight” of the components (1) and (2) is such that the total amount of the components (3) is 100 parts by weight. In general, when the amount of the component (1) is too small, the activity against ultraviolet rays decreases, and the hardness and impact resistance of the cured product decrease. Also,
If the amount of the component (2) is too large, the hardness and the heat resistance of the cured product also decrease.

On the other hand, the composition ratio of the component (3) is 1 to 49
Parts by weight, preferably 1 to 35 parts by weight (the total amount of components (1) to (3) is 100 parts by weight as described above). If the amount of the component (3) is too large, the curability decreases, and the curing time increases and the internal homogeneity decreases.

<Component (4): Photopolymerization Initiator> Component (4) of the photocurable composition according to the present invention is a photopolymerization initiator. It is clear that the components (1) and (3) having an ethylenically unsaturated bond are polymerized by a polyaddition reaction by cleavage of the unsaturated bond, but the mercapto compound of the component (2) having no such bond It is not always clear what the reaction mechanism is in the cured product.

However, irrespective of the reaction mechanism, the composition comprising the components (1) to (3) (and (5)) is photopolymerized and cured by the action of the component (4). Give the product. The photopolymerization initiator used in the present invention,
It is a compound represented by the formula [V]. One of these photopolymerization initiators may be used, or two or more thereof may be used in combination.

Specific examples of the photopolymerization initiator of the formula [V] include, for example, 4-phenylbenzophenone, 4-phenoxybenzophenone, 4,4'-diphenylbenzophenone, 4,4'-diphenoxybenzophenone and the like. .

<Composition (Part 2)> The photopolymerization initiator is used in an amount of 0.01 to 0.3 parts by weight based on 100 parts by weight of the total of components (1) + (2) + (3). Preferably 0.0
2 to 0.2 parts by weight. If the proportion of the photopolymerization initiator is too large, the internal homogeneity of the cured resin is deteriorated, and the hue is also deteriorated. On the other hand, if the amount of the photopolymerization initiator is too small, the composition cannot be sufficiently cured.

<Component (5): UV absorber> Component (5)
In order to improve the photocurability and internal homogeneity of the composition by absorbing ultraviolet rays present in the composition, rather than imparting ultraviolet ray cut properties to the photocured product of the composition of the present invention. It can be said to be used.

The ultraviolet absorber used in the present invention is selected from a benzophenone ultraviolet absorber and a benzotriazole ultraviolet absorber. These may be used together within each group and / or between each group.

Specific examples of the ultraviolet absorber used include:
2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-
Benzophenone compounds such as octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2- ( 2'-hydroxy-5-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dita-shary-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t Benzotriazole compounds such as (sali-butyl-5'-methylphenyl) benzotriazole.

<Composition (Part 3)> The ratio of these ultraviolet absorbers is 0.01 to 0.3 parts by weight, based on 100 parts by weight of the total of components (1) + (2) + (3). Preferably it is 0.03-0.1 weight part. If the blending ratio of the ultraviolet absorber is too large, the cured product will not be sufficiently cured, or the internal homogeneity of the cured product will be poor. On the other hand, if the proportion of the ultraviolet absorber is too small, the internal homogeneity of the cured product will be deteriorated and the desired ultraviolet cut property will not be obtained.

<Composition (Part 4)> It has been described above that the photocurable composition according to the present invention comprises components (1) to (5) and may additionally contain auxiliary components. By the way. Therefore, the photocurable composition according to the present invention may contain a radical polymerization accelerator, a polymerization regulator, a bottle inhibitor, if necessary.
A release agent and other additives can be blended.

<Photocuring> The photocurable composition of the present invention can be easily polymerized and cured by irradiation with active energy rays. The active energy ray has a wavelength of 200
Those having a range of about -600 nm are preferred. The atmosphere for irradiating the active energy ray may be any of ordinary air and an inert gas atmosphere. As a light source for active energy rays, a chemical lamp, a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, and the like are used.

The photo-curing may be performed under heating and / or decomposition of the compounded radical polymerization initiator in addition to the irradiation with the active energy ray. The photo-curing can be performed by placing the photo-curable composition in a mold made of a material transparent to the active energy ray and irradiating the composition with the active energy ray.

Therefore, the mold to be used may be a mold having the same profile as the shape of the optical element expected for the cured product, for example, a female mold for a lens. In making the desired optical element, it will generally not be necessary to pay special attention to the shape of the mold.

[0049]

The following examples and comparative examples are provided to further illustrate the present invention. “Parts” described in these examples means parts by weight. The cured resin properties described in these examples were determined by the following test methods. Appearance Visual Refractive Index Measured at 25 ° C. using an Atsube refractometer (manufactured by Atago). Optical distortion Measured with a Toshiba Strain Inspector (manufactured by Toshiba Glass Co., Ltd.).

Example 1 70 parts of 2,2-bis (methacryloyloxyethoxyphenyl) propane, 10 parts of pentaerythritol tetrakis (β-thiopropionate) and styrene 20
To 0.1 part of 4-phenylbenzophenone and 2-part
0.05 parts of hydroxy-4-octoxybenzophenone (Kyodo Yakuhin Co., Ltd., trade name "Biosorb 130") was added, and the mixture was uniformly stirred and mixed, followed by defoaming.
It was cast in a 6 mm deep mold made of a mirror-finished glass plate and silicon rubber under an argon gas atmosphere.

Then, ultraviolet rays were irradiated from a distance of 40 cm from the glass surface of the mold by a high-pressure mercury lamp with an output of 80 W / cm for 10 minutes each for 4 times, for a total of 40 minutes. After the obtained cured product was released from the mold, it was heated in an air oven at 100 ° C. for 2 hours to obtain a colorless and transparent cured product without optical distortion. The cured resin was cut and polished to measure physical properties, processed into dimensions of a measurement sample, and measured for physical properties. The obtained results are as shown in Table 1.

Example 2 70 parts of 2,2-bis (methacryloyloxy 3,5-dibromophenyl) propane, tris (2- (β-thiopropionyloxy) ethyl) triisocyanurate 10
Parts and 20 parts of styrene, 0.1 parts of 4-phenylbenzophenone and 2-hydroxy-4-octoxybenzophenone (Kyodo Yakuhin Co., Ltd.
0 "), uniformly stirred and mixed, followed by defoaming. The resulting composition was placed in a 6 mm deep mold composed of a mirror-finished glass plate and silicon rubber in an argon gas atmosphere. Cast below. Thereafter, the same operation as in Example 1 was performed to obtain a colorless and transparent cured product. The results of evaluating the physical properties are as shown in Table 1.

Example 3 The 4-phenylbenzophenone used in Example 1 was replaced with 4,
Example 1 except for replacing 4'-diphenylbenzophenone
A composition was prepared in the same manner as described above, cast and cured in the same manner, and the cured resin properties were measured in the same manner. The results were as shown in Table 1.

Example 4 The 4-phenylbenzophenone used in Example 1 was replaced with 4,
A composition was prepared in the same manner as in Example 1, except that 4'-diphenoxybenzophenone was used.
After curing, the physical properties of the cured resin were measured in the same manner. The results were as shown in Table 1.

Comparative Examples 1 to 3 The composition of the photocurable composition was changed as shown in Table 1, and it was prepared and polymerized and cured in the same manner as in Example 1. Was not obtained.

[0056]

[Table 1]

[0057]

According to the photocurable composition of the present invention, a cured product having excellent physical properties can be obtained by photocuring.
This is as described above in the section of “Summary of the Invention”.

Claims (1)

(57) [Claims] 1. A photocurable composition comprising the following components (1) to (5) (provided that component (1)
-(3), the total is 100 parts by weight). Component (1): 50 to 99 parts by weight of a polyfunctional photopolymerizable (meth) acrylate monomer Component (2): From the group consisting of compounds represented by the following formulas [I], [II] and [III] Mercapto compound selected 1 to 30 parts by weight [Wherein, R ¹ represents —CH ₂ — or —CH ₂ CH ₂ —, and R ² has 2 to 15 carbon atoms that may contain ether oxygen.
And a represents an integer of 2 to 6. A plurality of groups may be the same or different. [Formula 1] _c- (wherein, b and c each represent an integer of 1 to 8, d represents an integer of 0 to 2. A plurality of groups may be the same or different.) [Wherein, R ³ and R ⁴ each represent an alkylene group having 1 to 3 carbon atoms, and m and n each represent 0 or 1, p
Represents 1 or 2. A plurality of groups may be the same or different. Component (3): 1 to 49 parts by weight of a styrene monomer represented by the following formula [IV]: [Wherein, R ⁵ represents a hydrogen atom or a methyl group, X represents a halogen atom except fluorine, and q represents 0 or an integer of 1 to 5. A plurality of groups may be the same or different. Component (4): 0.01 to 0.3 parts by weight of a photopolymerization initiator compound represented by the following formula [V]: [Wherein, R ⁶ represents a phenyl group or a phenoxy group,
r and s are each an integer of 0 or 1 (provided that r +
s ≠ 0). A plurality of groups may be the same or different. Component (5): 0.01 to 0.2 parts by weight of an ultraviolet absorber selected from a benzophenone-based ultraviolet absorber and a benzotriazole-based ultraviolet absorber