JP2003192750A - Ultraviolet curing resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ultraviolet curing resin composition capable of forming cured products having a high tensile break elongation due to fine elongation characteristics even in a cured state and excellent compatibility, transparency, softness, moisture resistance and adhesion to substrates. <P>SOLUTION: The ultraviolet curing resin composition comprises (A) a polymer of conjugated diene type having at least one (meth)acryloyl group for one molecule in average, (B) a (meth)acrylic monomer and (C) a photo initiator. The mixing ratio of (A) component to (B) component is in the range of 10/90-90/10 based on the mass ratio. The mixing ratio of (C) component is 0.01-20 mass pts. to 100 mass pts. of the total amount of (A) component and (B) component. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to good elongation characteristics even in a cured state, high elongation at break, and compatibility,
The present invention relates to an ultraviolet curable resin composition capable of obtaining a cured product having excellent transparency, flexibility, adhesion and moisture resistance. The ultraviolet curable resin composition obtained in the present invention is, for example, an adhesive,
It is useful as an adhesive, a coating agent, a paint, an ink, a potting material, a sealing material, a sealant and the like.

[0002]

2. Description of the Related Art In recent years, resin compositions which can be cured by irradiation with ultraviolet rays or electron beams have been developed and used as coating materials for coatings, adhesives, adhesives and the like. Among such resin compositions, many examples of compositions using urethane acrylate are known, their use in coating applications has increased, and their required properties have become diverse. Among them, in coating materials and adhesives for precision parts such as electric and electronic parts, there is an increasing demand for materials that have large elongation of cured products, have excellent adhesion, and are excellent in moisture resistance and waterproofness. . Further, in recent years, an optical three-dimensional modeling method has been proposed in which a step of irradiating a photocurable liquid substance with light to form a cured resin layer is repeated to form a three-dimensional object in which a cured resin layer is laminated. [See JP-A-60-247515, etc.]. With the recent diversification of requirements for three-dimensional objects, for example, tires,
The application of this three-dimensional object to rubber products such as hoses, packings, and sealing materials is being considered.

[0003]

However, under the present circumstances, a photocurable resin composition having a sufficient balance of flexibility, moisture resistance and waterproofness of a cured product has not been obtained so far. Further, when a conventionally known photocurable resin composition is applied to the above-mentioned optical three-dimensional molding method, it is impossible to form a cured product having both rubber elasticity and tensile properties required for a rubber product. There was a point. Then,
In order to solve the above problems, the object of the present invention is to have excellent rubber elasticity with a high elongation even in a cured state, and to have excellent compatibility, transparency, flexibility and adhesion, and particularly a coating. An object of the present invention is to provide an ultraviolet curable resin composition having excellent moisture resistance, waterproofness and transparency when applied to a sealing material or a sealing material.

[0004]

According to the present invention, the above object is to provide a conjugated diene-based polymer (A) having at least one (meth) acryloyl group per molecule on average.
(Meth) acrylic monomer (B) and photoinitiator (C)
And the mixing ratio of the component (A) and the component (B) is in the range of 10/90 to 90/10 as a mass ratio, and
To provide an ultraviolet-curable resin composition, wherein the compounding ratio of the component (C) is 0.01 to 20 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). Achieved by

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A conjugated diene polymer (A) having an average of one or more (meth) acryloyl groups constituting the ultraviolet curable resin composition of the present invention per molecule.
(Hereinafter, it may be abbreviated as a conjugated diene polymer (A)) can be synthesized by various methods.
After synthesizing a conjugated diene-based polymer first, and then reacting the conjugated diene-based polymer with a dibasic unsaturated acid anhydride, subsequently, part or all of the acid anhydride groups in the obtained polymer, It is obtained by reacting a (meth) acrylic acid ester having a hydroxyl group in the ester moiety. As another method of obtaining the conjugated diene-based polymer (A), a conjugated diene-based polymer having a hydroxyl group and a (meth) acrylic acid ester having a hydroxyl group in the ester portion thereof may be used as a 2,4-tolylene diisocyanate compound. Method of reacting via a diisocyanate compound; a method of reacting a conjugated diene polymer having a carboxyl group with a (meth) acrylic acid ester having a glycidyl group in the ester portion; a conjugated diene polymer having a hydroxyl group and an ester portion Examples thereof include a method of reacting a (meth) acrylic acid ester having an acid halide group.

Preferably, the conjugated diene polymer (A)
Is to first synthesize a conjugated diene-based polymer, and then to react this conjugated diene-based polymer with a dibasic unsaturated acid anhydride, and subsequently, a part or all of the acid anhydride groups in the obtained polymer. Can be obtained by reacting with a (meth) acrylic acid ester having a hydroxyl group in the ester moiety.

Examples of the conjugated diene compound which constitutes the conjugated diene polymer as the raw material of the conjugated diene polymer (A) include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 1-phenylbutadiene, 2-phenylbutadiene, 1,1-diphenylbutadiene, 1,2-diphenylbutadiene, 2,3
-Diphenyl butadiene etc. are mentioned. The conjugated diene-based polymer may be composed of one kind of these conjugated diene compounds alone, or may be composed of two or more kinds. As the conjugated diene-based polymer, polybutadiene, polyisoprene, or a copolymer of a mixture of isoprene and butadiene is particularly preferable.

The conjugated diene polymer used as the raw material is
Produced by anionic polymerization of the above-mentioned conjugated diene compounds such as butadiene and isoprene with sodium naphthalene complex, alkyl lithium such as n-butyl lithium, s-butyl lithium, methyl lithium, ethyl lithium and pentyl lithium as an initiator. It can also be produced by radical polymerization using an azobisnitrile compound such as azobisisobutyronitrile or a peroxide such as benzoyl peroxide as an initiator. In addition, these polymerization reactions are usually performed under the conditions of a polymerization temperature of −78 ° C. to 150 ° C. and a polymerization time of 1 to 100 hours in the presence of an aliphatic or aromatic hydrocarbon solvent such as hexane, heptane, toluene, and xylene. Can be done at.

The number average molecular weight of the conjugated diene polymer before the introduction of the acid anhydride group is not limited in a strict sense, but it is usually preferably in the range of 2,000 to 100,000. More preferably, it is in the range of 1,000 to 50,000. When the number average molecular weight is less than 2,000, the crosslinking density becomes high, and the rubber elasticity after curing of the obtained ultraviolet curable resin composition tends to be impaired. On the other hand, if the number average molecular weight exceeds 100,000,
The viscosity of the obtained conjugated diene-based polymer (A) becomes high, and the workability tends to decrease, which is not preferable. The number average molecular weight as used herein means the polystyrene equivalent number average molecular weight measured by gel permeation chromatography (GPC).

Next, an acid anhydride group is introduced into the conjugated diene polymer obtained by the above method by reacting it with a dibasic unsaturated acid anhydride. In this reaction, for example, a conjugated diene-based polymer and a dibasic unsaturated acid anhydride are mixed in the presence of a solvent inert to the reaction such as hexane, heptane, toluene, xylene and other aliphatic or aromatic hydrocarbon solvents. Alternatively, in the absence of the solvent, the reaction can usually be performed by stirring at room temperature to 200 ° C. for 0.1 to 100 hours.

As such a dibasic unsaturated acid anhydride, for example, maleic anhydride can be used. The amount of the dibasic unsaturated acid anhydride used is such that the conjugated diene polymer (A) finally produced has an amount of one or more (meth) acryloyl groups per molecule as an average. The upper limit is not particularly limited as long as it is an amount capable of introducing an anhydride group into the conjugated diene polymer, but is usually in the range of 0.1 to 200 parts by mass with respect to 100 parts by mass of the conjugated diene polymer. It is preferably present, and more preferably in the range of 1 to 150 parts by mass. The amount of the acid anhydride group introduced into the conjugated diene-based polymer is usually in the range of 1 to 30 as an average per molecule by reacting under the above-mentioned conditions.
It is preferable to control in the range of 10 to 10.

The amount of the acid anhydride group introduced into the conjugated diene polymer by the above reaction can be quantified by an analytical means such as NMR or neutralization titration.

Subsequently, a part or all of the acid anhydride groups introduced into the conjugated diene-based polymer is reacted with a (meth) acrylic acid ester having a hydroxyl group in the ester moiety to give a conjugated diene-based polymer ( A) is obtained.

This reaction is carried out in the presence or absence of a reaction-inert solvent such as an aliphatic or aromatic hydrocarbon solvent such as hexane, heptane, toluene, xylene, etc.
Usually, it can be performed by stirring at room temperature to 200 ° C. for 0.1 to 100 hours.

Examples of the (meth) acrylic acid ester having a hydroxyl group in the ester moiety include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate and penta. Examples thereof include erythritol triacrylate, pentaerythritol trimethacrylate, and dipentaerythritol monohydroxy acrylate. Among these, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are preferable from the viewpoints of price and availability. The amount of the (meth) acrylic acid ester having a hydroxyl group in the ester portion must be such that the number of (meth) acryloyl groups in the conjugated diene-based polymer (A) is 1 or more as an average per molecule, Preferably 1
From the viewpoint that the number is from 30 to 30, more preferably from 2 to 10,
Generally, the conjugated diene-based polymer has an average of 0.01 to 1.5 with respect to the acid anhydride group per molecule.
The molar range is preferably, and more preferably 0.1 to 1 molar range. The conjugated diene polymer (A) has as an average per one molecule (meta)
If the number of acryloyl groups is less than 1, the curability of the resulting ultraviolet curable resin composition will be insufficient, while if it exceeds 30, the viscosity of the conjugated diene polymer (A) will be high and the workability will tend to be reduced. It is not preferable because

When a part of the acid anhydride group introduced into the conjugated diene-based polymer is reacted with a (meth) acrylic acid ester having a hydroxyl group in the ester part, the conjugated diene-based polymer (A) is obtained. Part of the acid anhydride group remains. When the ultraviolet curable resin composition of the present invention is prepared using this conjugated diene polymer (A), the acid anhydride group remaining in the resin composition and the water content in the air gradually change depending on the storage state. In some cases, the resin composition is cured in response to the reaction, and thus storage stability may be a problem. From this point of view, if necessary, the acid anhydride group remaining in the conjugated diene-based polymer (A) having at least one (meth) acryloyl group obtained by the above reaction is further reacted with an alcohol compound. , Can be converted into a carboxyl group and an ester group. The alcohol compound is not particularly limited, and examples thereof include methanol, ethanol, n-isopropanol, butanol and the like. The amount of the alcohol compound used is not strictly limited, but when an acid anhydride group remains in the conjugated diene polymer (A), it is usually 1 to 2 mol with respect to the remaining acid anhydride group. It is preferably in the double range.
When an acid anhydride group remains in the conjugated diene polymer (A), the reaction between the acid anhydride group and the alcohol compound is carried out by using an aliphatic or aromatic hydrocarbon solvent such as hexane, heptane, toluene or xylene. In the presence or absence of a solvent inert to the reaction of, usually, room temperature to 200 ℃
It can be performed by stirring for 0.1 to 100 hours.

The conjugated diene polymer (A) used in the present invention is also available as a commercial product.
RICON, product name "RIC-3500", "RI
C-3100 ", manufactured by Nippon Soda Co., Ltd., trade name" TE-200 "
0 ”and the like.

Examples of the (meth) acrylic monomer (B) constituting the ultraviolet curable resin composition of the present invention include isobornyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, morpholine (meth) acrylate and ethyl. (Meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dicyclopentenyl (meth) acrylate and the like can be mentioned. Among these, isobornyl (meth) is preferable from the viewpoint that the obtained ultraviolet curable resin composition has further excellent flexibility, moisture resistance and waterproofness after curing.
Acrylate is particularly preferred.

The amount ratio of the conjugated diene polymer (A) and the (meth) acrylic monomer (B) used must be such that the mixing ratio of the two is in the range of 90/10 to 10/90, The range is preferably 90/10 to 50/50. The amount ratio of the conjugated diene polymer (A) used is 10 as a mass ratio with respect to the (meth) acrylic monomer (B).
When it is less than 90%, that is, when it is less than 10% by mass, the elongation property after curing of the obtained ultraviolet curable resin composition becomes insufficient, while when it is more than 90/10, that is, when it is more than 90% by mass. When the amount is large, sufficient rubber elasticity cannot be obtained.

Examples of the photoinitiator (C) constituting the ultraviolet curable resin composition of the present invention include 2-hydroxy-2.
-Methyl-1-phenyl-propan-1-one [2-hydroxy-2-methylpropiophenone], 1-hydroxycyclohexyl phenyl ketone, bis (2,4,6
-Trimethylbenzoyl) phenylphosphine oxide, acetophenone, benzophenone, benzoin, benzoin methyl ether, benzoin ethyl ether,
Benzyl, 2-chlorothioxanthone and the like are used. These may be used alone or in combination of two or more. The amount of the photoinitiator (C) used needs to be 0.01 to 20 parts by mass with respect to 100 parts by mass of the total amount of the conjugated diene polymer (A) and the (meth) acrylic monomer (B) components. Yes, 0.5
More preferably, it is from 5 parts by mass. The amount of the photoinitiator (C) used is such that the conjugated diene-based polymer (A) and (meth)
When the total amount of the acrylic monomer (B) component is less than 0.01 parts by mass relative to 100 parts by mass, the curability is insufficient, while when it is more than 20 parts by mass, the curability is remarkable. There is no significant improvement effect, and economic efficiency is impaired.

The ultraviolet-curable resin composition of the present invention contains a leveling agent, a lubricant, and a leveling agent within the range not impairing the gist of the present invention.
Antioxidants, pigments, tackifying resins, silicone-based additives, fillers such as titanium oxide; polymers such as polyurethane, polymethylmethacrylate and polystyrene; (meth) acrylic monomers such as N-vinylpyrrolidone and N-vinylcaprolactam. Radical-polymerizable monomers other than;
You may further add additives, such as.

The UV-curable resin composition of the present invention comprises a conjugated diene polymer (A), a (meth) acrylic monomer (B), a photoinitiator (C) and, if necessary, an additive at room temperature. , Can be prepared by mixing using a conventional mixing means such as mixing with a stirring blade or a kneader.

The UV-curable resin composition of the present invention can be cured by irradiating it with a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a fluorescent lamp, or an ultraviolet-ray source such as ultraviolet rays contained in natural light. The irradiation time of the composition by the ultraviolet light source is generally in the range of 0.5 to 300 seconds, although it varies depending on the energy of the ultraviolet light generated from the ultraviolet light source.

The ultraviolet curable resin composition of the present invention has good elongation characteristics and high elongation at break even in a cured state.
It is also excellent in compatibility, transparency, flexibility and moisture resistance, and is useful for applications such as adhesives, pressure-sensitive adhesives, coating agents, paints, inks, potting materials, sealing materials, and sealants.

[0025]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Moreover, the evaluation of the obtained ultraviolet curable resin composition was performed as follows.

Compatibility The uniformity of the UV-curable resin compositions obtained in the following examples and comparative examples was visually observed and evaluated. ◯: Good compatibility (uniform) ×: Phase separation occurs

Cured state The ultraviolet curable resin compositions obtained in the following Examples and Comparative Examples were poured into a mold having a thickness of 0.5 mm so that the surface of the composition was protected from the influence of oxygen during curing. The thickness is 50μ
After covering with a polyester film of m, an ultraviolet ray was irradiated from an irradiation distance of 20 cm using an ultrahigh pressure mercury lamp (30 W / cm) for an irradiation time of 96 seconds to obtain a cured product. After peeling the polyester film from the cured product, the case where a transparent cured product was visually observed was evaluated as ◯.

Strength at Break and Elongation at Break The cured product obtained by peeling off the polyester film in the above was left in an atmosphere of 25 ° C. for 24 hours, and then the cured product was punched out using a No. 3 dumbbell to prepare a test piece, 20c.
A tensile test was performed at a tensile speed of m / min to measure the breaking strength and breaking elongation.

Hardness The cured product obtained by peeling off the polyester film in the above is laminated to have a thickness of 8 mm, and then JIS-
The hardness was determined using an A hardness meter.

Water Absorption Rate A test piece measuring 3 cm in length × 3 cm in width × 0.5 mm in thickness was prepared from the cured product obtained by peeling off the polyester film in the above and left for 72 hours in an atmosphere of 90 ° C. and 80% humidity. The subsequent moisture absorption rate was measured.

Moisture Permeability A test piece measuring 3 cm in length × 3 cm in width × 0.5 mm in thickness was prepared from the cured product obtained by peeling off the polyester film in the above, and allowed to stand at 40 ° C. in an atmosphere of 75% humidity for 24 hours. The moisture permeability after standing was measured.

Reference Example 1 [Conjugated diene polymer (A-
Synthesis of 1)] An isoprene monomer is subjected to anionic polymerization in n-hexane using n-butyllithium as an initiator,
Polyisoprene having a number average molecular weight of 20,000 was obtained. To 100 parts by weight of this polyisoprene, maleic anhydride 1.5
By adding parts by mass and reacting at 180 ° C. for 15 hours, polyisoprene having 3 acid anhydride groups per molecule on average was obtained. Next, 6.35 parts by mass of 2-hydroxyethyl methacrylate is added to 100 parts by mass of polyisoprene having three acid anhydride groups as an average per one molecule, and after reacting with light, the reaction is carried out at 120 ° C. for 10 hours. As a result, polyisoprene having three methacryloyl groups as an average per molecule (hereinafter, abbreviated as conjugated diene polymer (A-1)) was synthesized.

Examples 1 to 4 The conjugated diene polymer (A-1) obtained in Reference Example 1,
Isobornyl acrylate (abbreviated as IBXA; manufactured by Osaka Organic Chemical Industry Co., Ltd.) as the (meth) acrylic monomer (B), and Ciba Specialty Chemicals Co., Ltd. as the photoinitiator (C), trade name “Darocur-117”
3 "(2-hydroxy-2-methyl-1-phenylpropan-1-one [2-hydroxy-2-methylpropiophenone]) according to the formulation shown in Table 1 at room temperature using a stirring blade. The components were mixed to obtain an ultraviolet curable resin composition. The obtained ultraviolet curable resin composition was evaluated by the above method. The results are also shown in Table 1.

Comparative Examples 1 to 3 Instead of the conjugated diene polymer (A) used in the examples, a commercially available urethane acrylate oligomer (manufactured by Negami Kogyo Co., Ltd., trade name "Art Resin UN-5200") is used.
A ", the number of acryloyl groups possessed as one molecule average:
2), IBXA as the (meth) acrylic monomer (B), and Ciba Specialty Chemicals Co., Ltd. as the photoinitiator (C), trade name "Darocur-117".
3 "(2-hydroxy-2-methyl-1-phenylpropan-1-one [2-hydroxy-2-methylpropiophenone]) according to the formulation shown in Table 2.
The ultraviolet curable resin composition was obtained by the same method as described above. The obtained ultraviolet curable resin composition was evaluated by the above method. The results are also shown in Table 2.

[0035]

[Table 1]

[0036]

[Table 2]

From the results shown in Tables 1 and 2, the UV-curable resin composition having the composition specified in the present invention has excellent compatibility, good elongation characteristics even in the cured state, transparency, flexibility, and It can be seen that a cured product having excellent moisture resistance can be obtained.

[0038]

EFFECTS OF THE INVENTION According to the present invention, it is possible to obtain a cured product which has good elongation properties even in a cured state, high elongation at break, and excellent compatibility, transparency, flexibility, adhesion and moisture resistance. An ultraviolet curable composition capable of being provided is provided.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideo Takamatsu             36 Towada Stock Exchange, Kamisu Town, Kashima District, Ibaraki Prefecture             Inside the company Kuraray F-term (reference) 4J027 AA04 BA07 BA08 CB10 CC05                       CD06 CD08 CD09

Claims (2)

[Claims] 1. A conjugated diene polymer (A) having at least one (meth) acryloyl group per molecule on average, a (meth) acrylic monomer (B) and a photoinitiator (C), ) Component and (B) component are mixed in a mass ratio of 10/90 to 90/10, and the mixing ratio of (C) component is 100 mass of the total amount of (A) component and (B) component. The ultraviolet-curable resin composition is 0.01 to 20 parts by mass with respect to parts. 2. The conjugated diene polymer (A) is a polymer having one or more (meth) acryloyl groups as an average per molecule in a copolymer of polybutadiene, polyisoprene or a mixture of isoprene and butadiene. Item 2. The ultraviolet curable resin composition according to item 1.