JP2002338645A - Active energy ray-curing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active energy ray-curing composition which is low in viscosity and shrinkage and is excellent in rapid curing performance. SOLUTION: The active energy ray-curing composition comprises 5-50% by mass of a crosslinked fine particle (A) and 95-50% by mass of a radical polymerizing compound (B) having a sodium element concentration of 0.8-100 ppm, wherein the crosslinked fine particle (A) is produced by radical polymerizing a compound (a1) having one radical polymerizable ethylenically unsaturated group in the molecule and another compound (a2) having two or more radical polymerizable ehtylenically unsaturated groups in the molecule at an (a1):(a2) ratio of 55:45-95:5 (by mass).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active energy ray-curable composition containing reactive crosslinked fine particles. The present invention relates to an active energy ray-curable composition capable of simultaneously satisfying shrinkage and rapid curability.

[0002]

2. Description of the Related Art A radical polymerization type active energy ray-curable composition is rapidly cured by irradiation with active energy rays such as ultraviolet rays, electron beams, visible rays, etc., and is excellent in scratch resistance and chemical resistance. Is used in various surface processing fields. However, since a general active energy ray-curable composition has a relatively high viscosity, it is necessary to lower the viscosity by adding an organic solvent or a diluting monomer to facilitate coating. In this case, measures such as an increase in environmental load due to VOCs (volatile organic compounds) and skin irritation due to dilute monomers are required, and problems such as a decrease in curing speed may occur.

Further, an active energy ray-curable composition comprises:
Since the volume shrinkage during curing is large, a method of adding an oligomer or polymer having a high molecular weight is used as a method of reducing the shrinkage. However, with this approach,
The viscosity of the composition increases and the coating workability becomes poor,
It was not possible to avoid a decrease in curability due to a decrease in the number of radically polymerizable functional groups.

Further, in order to increase the curing rate of the active energy ray-curable composition, it is necessary to use a polyfunctional monomer. However, when a polyfunctional monomer is used, the curing shrinkage necessarily increases.

[0005] In order to satisfy these three conflicting performances of low viscosity, low shrinkage, and rapid curability, for example, a method of foaming a resin is disclosed in Japanese Patent Application Laid-Open No. 7-228644.
No. 2703125, Japanese Patent Publication No. 6-25
A composition to which a reactive microgel is added, such as that described in JP-A-210, has been proposed.

[0006] However, the method of foaming the resin has a problem that the coating film may have a poor appearance. Also, when a composition to which solid fine particles are added is used as a coating material, there is a problem that the coating film may have poor appearance.

[0007] The composition to which the reactive microgel is added is suitable for use as a resist composition for a printing plate. However, according to the findings of the present inventors, even if this reactive microgel is mixed with another radically polymerizable monomer and used as a solventless paint, the crosslinking density of the microgel is too low. Too much, the radical polymerizable monomer permeates into the inside of the microgel, and the microgel swells. As a result, the viscosity of the paint is increased, and the viscosity of the paint cannot be reduced.

[0008]

As described above, the conventional active energy ray-curable composition could not simultaneously achieve the excellent three properties of low viscosity, low shrinkage, and fast curability. In addition, when producing a thermosetting coating film or a thermosetting molded product, it was not possible to sufficiently satisfy the point of achieving both low viscosity and low shrinkage. An object of the present invention is to provide an active energy ray-curable composition satisfying these characteristics at the same time.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, it has been found that crosslinked fine particles and a radical polymerizable compound having a sodium element concentration of 0.8 to 100 ppm are used in combination. The present invention has been found to have lower viscosity and lower shrinkage than the conventionally known compositions and to show excellent curability, thereby completing the present invention.

That is, the present invention relates to a compound (a) having one radically polymerizable ethylenically unsaturated group in a molecule.
1) and a compound (a2) having two or more radically polymerizable ethylenically unsaturated groups in the molecule, represented by the following formula (a1):
(A2) = 5 to 50% by mass of crosslinked fine particles (A) radical-polymerized at 55:45 to 95: 5 (mass ratio), and radically polymerizable compound (B) 95 having a sodium element concentration of 0.8 to 100 ppm It is an active energy ray-curable composition containing 〜50% by mass.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. In the present invention, “(meth) acrylic acid” means “acrylic acid or methacrylic acid”
“(Meth) acryloyl group” means “acryloyl group or methacryloyl group”, respectively.

[Component (A)] In the present invention, crosslinked fine particles are used as the component (A). The crosslinked fine particles include a compound (a1) having one radically polymerizable ethylenically unsaturated group in the molecule and a compound (a2) having two or more radically polymerizable ethylenically unsaturated groups in the molecule. And
(A1): (a2) = 55: 45 to 95: 5 (mass ratio)
Are fine particles obtained by radical polymerization with

Here, the crosslinked fine particles (A) refer to those in a dry state from which water has been removed. As the particle structure,
A single structure, a core / shell structure, a multi-layer structure and the like can be mentioned.

[0014] In the molecule constituting the crosslinked fine particles (A), 1
The compound (a1) having two radically polymerizable ethylenically unsaturated groups may be appropriately selected in consideration of the application and required performance.

Specific examples thereof include aromatic vinyl monomers such as styrene, α-methylstyrene, α-chlorostyrene and vinyltoluene; vinyl ester monomers such as vinyl acetate and vinyl butyrate; ethyl vinyl ether;
Vinyl ethers such as phenyl vinyl ether; acrylamides such as acrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, N-butoxymethylacrylamide, Nt-butylacrylamide, acryloylmorpholine, and methylenebisacrylamide; (meth) acrylic acid; Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate,
Hexyl (meth) acrylate, 2- (meth) acrylate
Ethylhexyl, lauryl (meth) acrylate, stearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
4-hydroxybutyl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminomethyl (meth) acrylate, diethylaminomethyl (meth) acrylate,
Benzyl (meth) acrylate, cyclohexyl (meth) acrylate, phenoxyethyl (meth) acrylate,
Tricyclodecane (meth) acrylate, dicyclopentanyl (meth) acrylate, allyl (meth) acrylate,
Examples thereof include (meth) acrylates such as 2-ethoxyethyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and phenyl (meth) acrylate. These may be used alone or in combination of two or more.

In the molecule constituting the crosslinked fine particles (A), 2
The compound (a2) having two or more radically polymerizable ethylenically unsaturated groups is a component used for forming a crosslinked structure of fine particles.

Specific examples include ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and 1,4-butyl di (meth) acrylate. Butanediol, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, neopentyl glycol hydroxypivalate di (meth)
Acrylic acid ester, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, trimethylolpropane tri (meth)
Acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, glycerin tri (meth) acrylate, ethoxylated glycerin tri (meth) acryl Acid ester, tris (acryloyloxyethyl) isocyanurate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) (Meth) acrylates such as acrylate, dipentaerythritol hexa (meth) acrylate; polybasic acids (phthalic acid,
Polyester (poly) (meth) acrylates obtained by the reaction of polyhydric alcohols (eg, adipic acid), polyhydric alcohols (eg, ethylene glycol, hexanediol, polyethylene glycol, polytetramethylene glycol) with (meth) acrylic acid or a derivative thereof; glycidyl Epoxy poly (meth) obtained by reacting an ether compound (bisphenol A diglycidyl ether, ethylene glycol diglycidyl ether, etc.) with (meth) acrylic acid or a derivative thereof
Acrylates; isocyanate compounds (hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, etc.) and a (meth) acrylate having a hydroxyl group (2-hydroxyethyl (meth) acrylate, 2 -Hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc.), urethane poly (meth) acrylates; divinyl adipate, divinylbenzene, divinyl sulfone, triethylene glycol divinyl ether, 1,4
-Vinyl compounds such as cyclohexanedimethanol divinyl ether; and (meth) allyl compounds such as diallyl phthalate, diallyl isophthalate and diallyl maleate. These may be used alone or in combination of two or more.

Among the above, particularly preferred as compound (a1) are styrene, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, n- (meth) acrylate
Butyl, i-butyl (meth) acrylate, and t-butyl (meth) acrylate.

Particularly preferred as the compound (a2) is
1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, neopentyl glycol hydroxypivalate di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (Meta)
Acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

In the present invention, a compound (a1) having one radically polymerizable ethylenically unsaturated group in the molecule and two or more radically polymerizable ethylenes in the molecule, which constitute the crosslinked fine particles (A), The composition ratio ((a1) :( a2)) of the compound (a2) having an unsaturated group is preferably 55:45 to 95: 5 by mass ratio, and 65:35 to 9: 5.
3: 7 is more preferred.

In this composition ratio, when the compound (a1) exceeds 95% by mass, that is, when the compound (a2) is less than 5% by mass, the crosslinked density of the obtained crosslinked fine particles decreases, and When dispersed in B), the compound (B) permeates into the fine particles and the composition tends to extremely thicken. Compound (a1) is 55% by mass.
When the amount is less, that is, when the amount of the compound (a2) exceeds 45% by mass, gelation tends to occur during polymerization.

The crosslinked fine particles (A) can be obtained by a conventional radical polymerization method such as an emulsion polymerization method, a suspension polymerization method, or a suspension emulsion polymerization method, and the crosslinked fine particles are used in an active energy ray-curable composition. In order to obtain a particle size that can be easily dispersed, it is more preferable to obtain the particle size by an emulsion polymerization method.

The emulsion polymerization method is not particularly limited. Examples of the emulsion polymerization method include a batch mixing polymerization method, a monomer dropping method,
Examples include a pre-emulsion method, a seed polymerization method, and a multi-stage (core-shell) polymerization method.

In the case of the emulsion polymerization method, anionic emulsifiers such as sodium dodecylbenzenesulfonate, sodium dialkylsulfosuccinate, ammonium salt of polyoxyethylene alkylpropenyl phenyl ether sulfate, lauryl trimethyl ammonium chloride,
Cationic emulsifier such as stearyltrimethylammonium chloride, polyoxyethylene lauryl ether,
An emulsifier such as a nonionic emulsifier such as polyoxyethylene stearyl ether may be appropriately selected and used.

When these emulsifiers are used, a range of 0.1 to 8% by mass relative to 100% by mass of the total amount of the reaction system (solvent such as water, monomer, emulsifier, etc.) at the time of emulsion polymerization It is preferable to use them.

In the present invention, when the crosslinked fine particles (A) are obtained by emulsion polymerization using an emulsifier, for example, a polymerizable monomer (total of compound (a1) and compound (a2))
It is sufficient to use 100 to 300 parts by mass of pure water and 1 to 10 parts by mass of emulsifier with respect to 100 parts by mass.

Although the number average primary particle diameter of the crosslinked fine particles (A) is not particularly limited, the number average primary particle diameter is 10%.
It is preferably in the range of １０００1000 nm.

The number average primary particle diameter of the crosslinked fine particles (A) is 1
When the thickness is in the range of 0 to 1000 nm, the viscosity of the obtained active energy ray-curable composition is suppressed to be low, and the appearance of a coating film obtained by curing the composition tends to be excellent.

The crosslinked fine particles (A) obtained by emulsion polymerization or the like may be dried with water removed and then mixed with other components such as component (B).

The drying method is not particularly limited.
Examples of the method include pulverization by coagulation, washing, and drying, and spray drying (spray drying).

Of these, the spray drying method is particularly preferred in that the appearance of the coating film after curing becomes good.

[Component (B)] In the present invention, a radical polymerizable compound having a sodium element concentration in the range of 0.8 to 100 ppm may be used as the component (B), and the type of the radical polymerizable compound is not particularly limited. Not something.

The concentration of sodium element (mass basis in terms of sodium element) contained in the component (B) is 0.8
-100 ppm, preferably 1-80 pp
m. If the sodium concentration is lower than 0.8 ppm, the resulting composition tends to thicken,
If it exceeds ppm, the composition tends to be thixotropy.

Incidentally, the sodium element concentration in the present invention means that the sodium element concentration in the component (B) is 0.8 to 10%.
It may be within the range of 0 ppm, specifically, a compound containing a sodium component alone, or a combination of two or more, a compound containing a sodium component, a compound containing a sodium component separately, It includes all the sodium element concentrations in the form of a radical polymerizable compound containing no sodium component and containing a sodium component.

The method for measuring the concentration of sodium element in the component (B) is not particularly limited. For example, after performing pretreatment such as wet decomposition with mixed acid, incineration with a low-temperature incinerator and extraction with HCl, etc., measurement of sodium concentration can be performed by analysis methods such as atomic absorption method, ICP emission analysis method, etc. It is possible.

In the present invention, the method for adjusting the concentration of sodium element in the component (B) is not particularly limited.
For example, first, the sodium component contained in the radical polymerizable compound to be used is converted into a sodium element mass.
As a result, when the necessary amount of the sodium component is already contained (described above), it may be used as it is as the component (B). If the sodium component is insufficient (or above), a component prepared by mixing and dissolving the sodium component separately in the radically polymerizable compound to adjust the concentration of the necessary amount of sodium element to component (B) is used. Good.

The method for adjusting the concentration of the sodium element in the component (B) is not particularly limited, and a known dispersing machine such as a homodisper, a dissolver, a three-roll mill, a ball mill or the like may be appropriately selected and used.

In the present invention, specific examples of the radically polymerizable compound (B) include, for example, the various (meta) compounds listed above as specific examples of the compounds (a1) and (a2) having an ethylenically unsaturated group. ) Compounds having an acryloyl group can be mentioned. These may be used alone or in combination of two or more.

Among these, the radically polymerizable compound (B) which is liquid at room temperature can easily adjust the concentration of sodium element, is excellent in the workability of application of the active energy ray-curable composition, and has excellent storage stability. It is preferable in that it can be kept good.

Here, the room temperature refers to 10 to 35 ° C., and the liquid state has a viscosity at room temperature of 100,000 mPa · s.
s or less.

From the viewpoint of versatility, trimethylolpropane triacrylate, dipentaerthritol hexaacrylate, and the like have low viscosities. Hydroxybutyl, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate and the like are preferred.

In addition, the component (B) preferably contains at least 1% by mass or more of a compound having at least one hydroxyl group and (meth) acryloyl group in the molecule. It is more preferable in view of the dispersion stability of (A).

When a sodium component is contained in the component (B), the type of the sodium component is not particularly limited.

Specific examples of the sodium component used in the present invention include, for example, sodium metal, sodium acetate, sodium alginate, sodium azide, sodium benzenesulfonate, sodium borate, sodium chlorite, sodium chloroacetate, p-chlorobenzene. Sodium sulfonate, sodium chloride, sodium citrate, sodium cyanate, sodium cyanide, sodium N-dodecanoyl sarcosinate, sodium ethylate, sodium fluoride, sodium hydroxide, sodium iodide, sodium maleate, sodium propionate , Sodium sulfate, sodium dodecylbenzenesulfonate, sodium dialkylsulfosuccinate and the like. These may be used alone or in combination of two or more.

The sodium component dissolves in a small amount of water contained in the radically polymerizable compound. Therefore, it is desirable that the sodium component used has high solubility in water.

As specific examples, for example, sodium sulfate, sodium chloride, sodium carbonate, and sodium citrate are preferable.

In the active energy ray-curable composition of the present invention, the composition ratio of the component (A) to the component (B) is such that the component (A) is 5 to 50% by mass in the active energy ray-curable composition. The range, component (B), is in the range of 95 to 50% by mass.

Preferably, component (A) is in the range of 10 to 40% by weight and component (B) is in the range of 90 to 60% by weight.

If the constituent ratio of component (A) exceeds 50% by mass, the viscosity of the resulting composition tends to increase. When the component ratio of the component (A) is less than 5% by mass, not only does the curability of the obtained composition decrease, but also the curing shrinkage tends to increase.

The composition of the present invention can be cured by irradiating an active energy ray.

Therefore, an active energy ray-sensitive radical polymerization initiator (hereinafter referred to as a photopolymerization initiator) may be appropriately added to the composition of the present invention.

The active energy rays referred to in the present invention are not particularly limited, such as electron beams, ultraviolet rays, and visible rays, but include known active energy rays.

For example, when an electron beam is used as an active energy ray when curing the composition of the present invention, the composition can be cured without using a photopolymerization initiator.

However, when the composition of the present invention is cured by an active energy ray other than an electron beam, it is preferable to add a photopolymerization initiator as the component (C) to the composition of the present invention.

Specific examples of the photopolymerization initiator include, for example,
Thioxanthones such as benzophenone, 4,4-bis (diethylamino) benzophenone, t-butylanthraquinone, 2-ethylanthraquinone, 2,4-diethylthioxanthone, isopropylthioxanthone and 2,4-dichlorothioxanthone; diethoxyacetophenone, 2-hydroxy -2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2
-Morpholino (4-thiomethylphenyl) propane-1
-One, 2-benzyl-2-dimethylamino-1- (4
Acetophenones such as -morpholinophenyl) -butanone; benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether;
6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,
Acylphosphine oxides such as 4,4-trimethylpentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; methylbenzoyl formate; 1,7-bisacridinyl heptane; 9-phenylacridine And the like. These may be used alone or in combination of two or more.

When a photopolymerization initiator is used in the present invention, the amount thereof is preferably in the range of 0.01 to 20 parts by mass based on 100 parts by mass of the total of the components (A) and (B). The range of 0.1 to 10 parts by mass is particularly preferred.

When the amount of the photopolymerization initiator is within the above range, there is an advantage that the active energy ray curability, the deep part curability, the substantial productivity are excellent, and the cured film after the curing is also excellent in low odor. is there.

[Other Components] The active energy ray-curable composition of the present invention may further contain, if necessary, methyl methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and 4-dimethylaminobenzoic acid. Known photosensitizers such as amyl and 4-dimethylaminoacetophenone can also be added. In addition, if necessary, release agents, lubricants,
Known additives such as a plasticizer, an antioxidant, an ultraviolet absorber, a flame retardant, a flame retardant auxiliary, a polymerization inhibitor, a filler, an organic solvent, a pigment, a dye, and a silane coupling agent can also be added.

The content of these additives is not particularly limited, and they can be used as long as the effects of the composition of the present invention are not impaired.

[Other Characteristics] The present invention provides a composition containing the component (A) by appropriately selecting the component (B) and adjusting its content and the concentration of sodium element in the component (B). The viscosity can be easily adjusted to a desired viscosity.

The viscosity of the active energy ray-curable composition of the present invention is not particularly limited, but from the viewpoint of coating workability, the E-type viscosity at 25 ° C. is 10,000 mPa · s.
s or less, more preferably 5000 mPa · s or less.

The curing shrinkage of the active energy ray-curable composition of the present invention can be adjusted by appropriately adjusting the components and content of the component (A).

The curing shrinkage is preferably 13% or less, more preferably 11% or less, from the viewpoint of adhesion to the substrate and preventing the substrate from warping.

[Production Method] In order to produce the active energy ray-curable composition of the present invention, the respective components may be appropriately mixed,
Although there is no particular limitation according to the present invention, it is preferable that the composition is excellent in coating workability, and it is desirable that the composition is a uniform dispersion. .

For example, the component (A), the component (B) and, if necessary, the component (C), a sodium component, a photosensitizer, a release agent and the like are mixed, and a homodisper, a dissolver,
The dispersion can be performed using an arbitrary dispersing machine such as a three-roll mill or a ball mill. Alternatively, the component (A) is replaced with the component (B)
After mixing and dispersing, other components can be further mixed and dispersed, and the composition can be produced stepwise.

The active energy ray-curable composition of the present invention can be used for various applications such as hard coating materials for woodwork, coating materials for paper, molded products, adhesives, paints, inks, resists, and optical molding materials.

[0067]

The present invention will be described in more detail with reference to the following examples. In the following description, “parts” means “parts by mass” unless otherwise specified.

<Example 1> [Preparation of raw material pre-emulsion] 50 parts of methyl methacrylate and 30 parts of n-butyl methacrylate as component (a1), 15 parts of pentaerythritol triacrylate and 5 parts of divinylbenzene as component (a2)
0.3 parts of peroxide initiator (manufactured by NOF Corporation, trade name: Perbutyl H), polyoxyethylene alkylpropenyl phenyl ether sulfate ammonium salt (manufactured by Asahi Denka Co., Ltd., trade name: Adekarya Soap SE-10N) ) 5
And 40 parts of pure water, followed by stirring to obtain a pre-emulsion.

[Preparation of Crosslinked Fine Particles (AI)]
145 parts of pure water, Rongalit 0.06
Parts, disodium ethylenediaminetetraacetate 0.001
, 0.0005 part of ferrous sulfate heptahydrate, and the mixture was stirred at 150 rpm with an irrigated stir bar. After the inside of the system was replaced with nitrogen gas by aeration with nitrogen gas, the temperature was raised. When the internal temperature reached 60 ° C., the dropping of the pre-emulsion was started, and 40 parts of the pre-emulsion were dropped over 30 minutes, and further 30 minutes. Stirring was continued at an internal temperature of 60 ° C. Thereafter, the remaining 120 parts of the pre-emulsion was dropped over 2 hours. When stirring was continued for 2 hours while maintaining the internal temperature at 60 ° C., the mixture was cooled to obtain a milky white emulsion. A part of the obtained emulsion was sampled, and the average particle size R1 of the primary particles at 25 ° C. was measured using a dynamic light scattering photometer DLS-600 manufactured by Otsuka Electronics Co., Ltd.
It was 8.6 nm.

The obtained emulsion was sprayed using an L-8 type spray dryer manufactured by Okawara Kakoki Co., Ltd. at a chamber inlet temperature of 120 ° C. and a chamber outlet temperature of 60 ° C.
Spray drying was performed under the condition of an atomizer rotation number of 25,000 rpm. No blocking was observed in the obtained crosslinked fine particles (A-I), indicating high fluidity.

[Preparation of Crosslinked Fine Particles (A-II) to (A-IV)] Except having the composition shown in Table 1, the crosslinked fine particles (A) were prepared in the same manner as in the preparation of the crosslinked fine particles (AI). −II)
To (A-IV).

[Adjustment of concentration of sodium element of component (B)] Tripropylene glycol diacrylate (I)
(Sodium element concentration by ICP emission spectroscopy is 0.2 ppm).
03 parts by mass was stirred at 4000 rpm for 15 minutes using a homodisper to obtain tripropylene glycol diacrylate (II) having a sodium concentration of 100.2 ppm. 64. Tripropylene glycol diacrylate (I)
35 parts by mass and 0.65 parts by mass of tripropylene glycol diacrylate (II) were added to 40 parts by using a homodisper.
Stir at 00 rpm for 5 minutes, sodium concentration 1.2 pp
m of tripropylene glycol diacrylate was prepared.

(Method for Measuring Sodium Element Concentration) About 75 mg of a component is placed in a quartz flask, and manufactured by PROLABO mi.
Microwave wet decomposition was performed using sulfuric acid, nitric acid, and hydrogen peroxide using Crodigest 300. Then 50
diluted to a volume of 2,000 ml and manufactured by Nippon Jarreel Asch ICA.
The sodium element concentration was measured by ICP emission spectroscopy using P-575 MK-II.

[Preparation of active energy ray-curable composition]
35 parts of crosslinked fine particles (AI), sodium concentration of 1.2
65 parts by weight of tripropylene glycol diacrylate and 3 parts of 1-hydroxycyclohexyl-phenylketone (trade name Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) were mixed, and the mixture was stirred with a homodisper at 4000 rpm for 5 minutes. Thus, a milky white active energy ray-curable composition was obtained.

[Evaluation of the active energy ray-curable composition]
The following evaluations were performed on the active energy ray-curable composition, and as shown in Table 2, it was confirmed that the composition had excellent characteristics.

E-type viscosity: E-type viscosity at 25 ° C. of the obtained active energy ray-curable composition was measured and evaluated according to the following evaluation criteria. ：: 20 to 1000 mPa · s ×: 1000 mPa · s or more Curing shrinkage: The curing shrinkage due to the difference between the liquid specific gravity and the cured product specific gravity of the obtained active energy ray-curable composition was measured and evaluated according to the following evaluation criteria. . ：: Less than 12% ×: 12% or more Coating appearance: The obtained active energy ray-curable composition was
Paint on glass substrate with bar coater # 3, 80W /
Ultraviolet rays were irradiated under the conditions of three high-pressure mercury lamps having a diameter of 3 cm, a lamp height of 10 cm, and a conveyor speed of 3 m / min to completely cure the coating film. The appearance of the cured coating film was visually evaluated as follows. ：: good in transparent and smooth surface ×: cloudy, unevenness remains, unusable Touch dryness: The obtained active energy ray-curable composition is coated on a glass substrate with a bar coater # 3, 80
Irradiate ultraviolet light under the conditions of one high-pressure mercury lamp of W / cm, lamp height of 10 cm, and conveyor speed of 16 m / min. Was evaluated according to the evaluation criteria described above. ○: 4 times or less ×: 5 times or more

[0077]

[Table 1] The abbreviations in Table 1 are as follows: MMA: methyl methacrylate n-BMA: n-butyl methacrylate PETA: pentaerythritol triacrylate TMPTA: trimethylolpropane triacrylate DVB: divinylbenzene

[0078]

[Table 2] (Note 1) AV: spherical silica gel (particle size: 50 nm). (Note 2) The compound showed thixotropy, and E-type viscosity could not be measured. (Note 3) The compounding amount of the component (A) is large and cannot be uniformly dispersed.
E-type viscosity could not be measured. (Note 4) Air was mixed into the coating film, and the curing shrinkage ratio could not be measured.

The abbreviations in Table 2 are as follows. TPGDA (I): tripropylene glycol diacrylate (concentration of sodium element: 0.2 ppm) TPGDA (II): tripropylene glycol diacrylate (concentration of sodium element: 100.2 ppm) TMPTA: trimethylolpropane triacrylate 4HBA: 4-hydroxybutyl acrylate Irg184: Photopolymerization initiator (trade name Irgacure 184, manufactured by Ciba Specialty Chemicals Inc.).

<Examples 2 to 6 and Comparative Examples 1 to 7> First, the above-mentioned crosslinked fine particles (A-
In the same manner as in the preparation of I), the crosslinked fine particles (A-II) to
(A-IV) was obtained. Further, an active energy ray-curable composition was prepared in the same manner as in Example 1 except that the components and the composition ratios shown in Table 2 were changed. In addition, T of component (B)
The mixing ratio of MPTA / 4HBA is 5/3, including Examples 4 to 6, and Comparative Examples 1, 4 to 7. These active energy ray-curable compositions were evaluated in the same manner as in Example 1. Table 2 shows the results.

As shown in Table 2, in Examples 1 to 6, E
Good results were shown for mold viscosity, cure shrinkage, and dryness to the touch, and it was confirmed that an active energy ray-curable composition that simultaneously satisfies the three performances of low viscosity, low shrinkage, and fast curing was obtained. .

On the other hand, in Comparative Example 1, since no crosslinked fine particles were used, the curing shrinkage and the dryness to the touch were inferior.

In Comparative Example 2, a low viscosity could not be achieved because the concentration of sodium in the active energy ray composition was low.

In Comparative Example 3, since the sodium concentration in the composition (B) was high, the composition exhibited thixotropy and the E-type viscosity could not be measured. Also, although a cured coating was obtained,
Air was mixed into the coating film, and the curing shrinkage could not be measured.

In Comparative Example 4, rapid curability was not obtained because the amount of crosslinked fine particles was small.

In Comparative Example 5, the viscosity was increased due to the large amount of the crosslinked fine particles added, and a coating film could not be formed.

In Comparative Example 6, since the crosslinked fine particles (A-IV) were produced without using the compound a2, the degree of crosslinking of the crosslinked fine particles was reduced, the composition was extremely thickened, and the viscosity could not be reduced. .

In Comparative Example 7, silica gel (AV) was mixed and used in place of the crosslinked fine particles, so that an active energy ray-curable composition achieving high reactivity could not be obtained. No appearance was obtained.

[0089]

As described above, the present invention lowers the viscosity of the entire composition by adding the compound (B) having a sodium element concentration in a specific range to the composition containing the crosslinked fine particles (A). This makes it possible to obtain an active energy ray-curable composition which can satisfy both low shrinkage and fast curability at the same time.

As a result, it has become possible to simultaneously satisfy three performances of low viscosity, low shrinkage, and fast curing, which cannot be achieved with the conventional active energy ray-curable resin composition.

Thus, the composition of the present invention can be used in a wide range of fields such as molded articles, adhesives, paints, inks, resists, castings, and optical molding materials. In particular, since it is excellent in coating workability and rapid curing property, has low shrinkage upon curing, and does not warp the substrate, it is suitable for precision articles in the field of optical materials and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 5/00 C09D 5/00 Z (72) Inventor Juichi Fujimoto 1st Sunadabashi Yomachi, Higashi-ku, Nagoya City, Aichi Prefecture No. 60 Inside the Mitsubishi Rayon Co., Ltd. Product Development Laboratory (72) Inventor Kaoru Terasawa No. 1-60, Sunadabashi Yomachi, Higashi-ku, Nagoya-shi, Aichi F-term inside the Mitsubishi Rayon Co., Ltd. Product Development Laboratory 4J002 BC011 BC041 BC071 BC081 BC091 BC111 BE011 BE041 BF011 BF021 BF041 BF051 BG011 BG071 BG131 BJ001 BN111 BQ001 CD201 CF271 CH051 CK021 DA117 DD037 DD057 DD087 DE057 DE197 DF017 DF027 DG047 DK007 EC077 ED088 EE028 EE058 EG027 EG057 EH076 EU018 EU238 EV257 EV308 EW148 FD158 GH01 GJ01 GP03 4J026 AA17 AA21 AA31 AA37 AA38 AA40 AA43 AA45 AA46 AA47 AA48 AA50 AA55 BA28 BA30 DA03 DA04 DA07 DB05 DB36 GA07 GA 09 4J038 CC022 CF012 CG032 CG072 CG142 CG172 CH022 CH032 CH052 CH062 CH072 CH082 CH122 CH202 CJ022 CJ082 CJ112 CJ252 CJ272 CJ282 FA081 FA091 FA121 FA141 FA151 FA161 FA201 FA251 FA261 FA281 HA066 HA116 HA246 HA276B18 JA18 J31 JA18 KA09 KA20 MA02 MA15 NA04 NA11 NA17 NA24 NA26 PA17 PB14 PC06 PC10

Claims (3)

[Claims] 1. A compound (a1) having one radically polymerizable ethylenically unsaturated group in the molecule and a compound (a2) having two or more radically polymerizable ethylenically unsaturated groups in the molecule And (a1) :( a2) = 55: 45
Activity containing 5 to 50% by mass of crosslinked fine particles (A) radical-polymerized at a ratio of 95 to 5 (mass ratio) and 95 to 50% by mass of a radical polymerizable compound (B) having a sodium element concentration of 0.8 to 100 ppm. Energy ray curable composition. 2. An active energy ray-sensitive radical polymerization initiator (C) is contained in an amount of 0.01 to 20 parts by mass based on 100 parts by mass of the total of the components (A) and (B). The active energy ray-curable composition according to item 1. 3. The active energy ray-curable composition according to claim 1, wherein the component (B) is liquid at room temperature.