JP3315562B2 - Curable resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin containing a polymerizable polymer or oligomer containing a reactive diluent having excellent curability, flexibility and workability, low skin irritation and low water absorption. It relates to a composition.

[0002]

2. Description of the Related Art Acrylic esters used as reactive diluents include 2-ethylhexyl acrylate, methoxydipropylene glycol acrylate, tetrahydrofurfuryl acrylate, phenoxy polyethylene glycol acrylate, isobornyl acrylate, and nonylphenol poly. Monofunctional acrylates such as ethoxylated acrylate, and 1,6 hexanediol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate,
Bifunctional acrylates such as polypropylene glycol diacrylate and bisphenol A polyethoxylated diacrylate, and trimethylolpropane triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexaacrylate, and trimethylolpropane polyethoxylated triacrylate Multifunctional acrylates such as acrylates are known.

[0003] These acrylates are desired to satisfy the performance required as a reactive diluent, ie, high dilutability, low skin irritation, low water absorption, quick curing, flexibility and the like. Few satisfy all performances.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the state of the prior art, and aims at low viscosity, high dilution and flexibility, low water absorption,
An object of the present invention is to provide a resin composition which has a low skin irritation property and contains a specific reactive diluent which cures quickly.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, a resin composition containing polytetramethylene glycol diacrylate represented by a specific structural formula has been cured. It was found that it had excellent properties, flexibility and workability, and had low skin irritation and low water absorption.

That is, the present invention relates to a resin composition containing a curable resin, a photo or thermal polymerization initiator, and a reactive diluent, wherein the reactive diluent is polytetramethylene glycol diacrylate represented by the following general formula: A resin composition characterized by having:

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In the present invention, the average value of n for the composition of the polytetramethylene glycol diacrylate is 2 to 6
, Preferably 2 to 4, more preferably 2.5 to 3.5. If the average value of n is less than the above value, skin irritation and flexibility are inferior.
Poor curability is not preferred.

[0008] The polytetramethylene glycol diacrylate as the reactive diluent of the present invention employs dehydration esterification reaction of polytetramethylene glycol with acrylic acid, transesterification reaction with lower alkyl acrylate, and acrylic acid chloride. It can be produced by a desalination reaction. Here, in the case of a dehydration esterification reaction, it is preferable to use an azeotropic solvent for distilling off generated water, since water can be easily separated, and such a boiling point is preferably from 60 to 20.
If it is 0 degreeC, Preferably it is 60-150 degreeC, it can be used. However, if the boiling point is too low, the reaction rate is low, and if it is too high, a polymerization reaction occurs, which is not preferable.

Examples of the solvent include benzenetoluene,
Aromatic hydrocarbons such as xylene, cyclohexane, alicyclic hydrocarbons such as methylcyclohexane, n-heptane,
Examples thereof include aliphatic hydrocarbons such as n-hexane. The amount used is 50 to 300 wt%, preferably 50 to 200 wt%, based on the mixture of polytetramethylene glycol and acrylic acid.

As the acidic catalyst to be used, organic sulfonic acid compounds such as P-toluenesulfonic acid, sulfuric acid, methanesulfonic acid, and sulfonic acid ion exchange resin can be used. It is 2 to 30% by weight, preferably 2 to 10% by weight based on the mixture of acrylic acid.

Further, a polymerization inhibitor can be added to prevent polymerization in the reaction system. Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, di-tertbutylhydroxytoluene, benzoquinone, phenothiazine P-phenylenediamine, and air. The amount used is from 0.0001 to the mixture of polytetramethylene glycol and acrylic acid.
3 wt%, preferably 0.001 to 1 wt%. These may be used alone or in combination. The molar ratio of acrylic acid to polytetramethylene glycol is
It is 0.5 to 10, preferably 0.8 to 2.

The resin composition in the present invention is intended for a photopolymerizable composition and a thermopolymerizable composition. Polymerizable oligomers and polymers used in the resin composition of the present invention include:
Examples include vinyl group-containing oligomers such as urethane-modified (meth) acrylates, epoxy-modified (meth) acrylates, polyester (meth) acrylates, and polymer polyol-based (meth) acrylates, and polymers. However, these oligomers and polymers may be used alone or in combination.

The photopolymerization initiator used in the resin composition of the present invention includes benzoin compounds such as benzoin and benzoin alkyl ethers, phenylacetone compounds such as 2,2-diethoxy-2-phenylacetone, and anthraquinone compounds. Thioxanthone compounds, benzophenone compounds, xanthone compounds, ketal compounds and the like. These may be used in combination with a known photopolymerization accelerator, or may be used alone or in combination. The amount used is 0.1 to 30 wt.
%, Preferably 1 to 10% by weight.

Examples of the thermal polymerization initiator include organic peroxide compounds such as tert-butyl peroxide and cumyl peroxide, organic azo compounds such as azo-bis-isobutanol acetate, and redox initiator compounds. . These may be used alone or in combination. The amount used is 0.01 to 10 w for the curable resin.
t%, preferably 0.5 to 3 wt%. The amount of the reactive diluent of the present invention is 5 to 95 wt with respect to the curable resin.
%, Preferably 20 to 80 wt%. If the amount is less than the above amount, the dilutability is inferior. If the amount is more than the above amount, the properties of the polymerizable polymer and oligomer are impaired, which is not preferable.

[0015]

The present invention will be described in detail with reference to Synthesis Examples, Examples and Comparative Examples, which do not limit the present invention.

Synthesis Example 1 250 g of polytetramethylene glycol (average molecular weight 250, n average = 3.2), benzene, were placed in a 1 liter reactor equipped with a stirrer, thermometer, air inlet tube, cooling tube, and water separator. When 250 g, sulfuric acid 5 g, hydroquinone monomethyl ether 0.4 g, and acrylic acid 216 g were put and heated and stirred while blowing air, azeotrope of benzene and water was distilled off at 82 ° C. Only water out of the distillate was taken out of the system to continue the reaction, and the reaction product was checked by gas chromatography. When the amount of the monoester became 0.5% or less, the reaction was stopped by cooling. At that time, the dehydration amount is 36
g. Next, after excess acrylic acid and sulfuric acid were neutralized with a 10% aqueous sodium hydroxide solution, the excess alkali fraction was washed with ion-exchanged water. Further, benzene was distilled off under reduced pressure at 60 ° C. or lower to obtain polytetramethylene glycol diacrylate (average molecular weight: 358) as a transparent liquid. As a result of analyzing the composition of the obtained compound by gas chromatography, the composition of n = 2 was 15.3% by weight, and the composition of n = 3 was 4%.
The composition of 6.8% by weight and n = 4 was 37.9% by weight.

Synthesis Example 2 In a reactor similar to Synthesis Example 1, 325 g of polytetramethylene glycol (average molecular weight: 650, n average = 8.8) was added.
When 250 g of benzene, 5 g of sulfuric acid, 0.4 g of hydroquinone monomethyl ether and 108 g of acrylic acid were added and heated and stirred while blowing air, an azeotrope of benzene and water was distilled off at 82 ° C. Of the distillate, only water was taken out of the system to continue the reaction, and the reaction product was checked by gas chromatography. When the amount of the monoester became 0.5% or less, the reaction was stopped by cooling. At that time, the dehydration amount is 18
g. Next, the mixture was neutralized in the same manner as in Synthesis Example 1, and then washed with ion-exchanged water. Further, benzene was distilled off under reduced pressure at 60 ° C. or lower to obtain polytetramethylene glycol diacrylate (average molecular weight: 758) as a transparent liquid. As a result of analyzing the composition of the obtained compound by gas chromatography, the composition of n = 6 was 5.3% by weight, and the composition of n = 7 was 9.
7% by weight, composition of n = 8 is 15.4% by weight, composition of n = 9 is 44.1% by weight, composition of n = 10 is 28.5% by weight
Had become.

Synthesis Example 3 Polytetramethylene glycol (average molecular weight 650, n) was placed in a 1-liter reactor equipped with a stirrer, a thermometer, and a cooling tube.
Average value = 8.8) 500 g, isophorone diisocyanate 343 g, hydroquinone monomethyl ether 0.5
g and 0.5 g of dibutyltin laurate were stirred and generated heat.
Next, after reacting at 80 ° C. for 2 hours, the NCO equivalent was measured and found to be a theoretical value (1.823 meq / g).
Add 178 g of hydroxyethyl acrylate and add 80 ° C
At the second stage. Five hours later, when a peak at 2250 cm ^-1 was confirmed in the infrared absorption spectrum, no peak was detected. The reaction was stopped by cooling, and urethane acrylate as a polymerizable oligomer was obtained.

Example 1 18 parts by weight of the polytetramethylene glycol diacrylate (average molecular weight: 358) of Synthesis Example 1 as a reactive diluent was added to 100 parts by weight of bisphenol A diglycidyl ether diacrylate as a polymerizable oligomer. , 33 parts by weight, and 100 parts by weight, three compositions having different concentrations were prepared. Next, the viscosity of this composition at 25 ° C. was measured. The results are shown in Table 1.

Example 2 Three kinds of compositions were obtained in the same manner as in Example 1 except that the urethane acrylate of Synthesis Example 3 was used instead of bisphenol A diglycidyl ether diacrylate as a polymerizable oligomer. The viscosity was measured at 0 ° C. The results are shown in Table-2.

Comparative Example 1 Instead of the polytetramethylene glycol diacrylate of Synthesis Example 1, triethylene glycol diacrylate (3
Except that EG-A (Kyoeisha Chemical Co., Ltd.) was used, a composition was obtained and the viscosity was measured according to Example 1. The results are shown in Table 1.

Comparative Example 2 The composition was the same as in Example 1 except that tripropylene glycol diacrylate (3PG-A, manufactured by Kyoeisha Chemical Co., Ltd.) was used instead of polytetramethylene glycol diacrylate in Synthesis Example 1. The product was obtained and the viscosity was measured. The results are shown in Table 1.

Comparative Example 3 Instead of the polytetramethylene glycol diacrylate of Synthesis Example 1, triethylene glycol diacrylate (3
Except that EG-A (Kyoeisha Chemical Co., Ltd.) was used, a composition was obtained and the viscosity was measured according to Example 2. The results are shown in Table-2.

Comparative Example 4 The composition was the same as in Example 2 except that tripropylene glycol diacrylate (3PG-A, manufactured by Kyoeisha Chemical Co., Ltd.) was used instead of polytetramethylene glycol diacrylate in Synthesis Example 1. The product was obtained and the viscosity was measured. The results are shown in Table-2.

Example 3 A mixed solution of 100 parts by weight of bisphenol A diglycidyl ether diacrylate as a polymerizable oligomer and 33 parts by weight of polytetramethylene glycol diacrylate (average molecular weight 358) of Synthesis Example 1 as a reactive diluent was prepared. Prepared. Next, 4 parts by weight of Irgacure 651 (manufactured by Nippon Ciba-Geigy Corporation) as a photopolymerization initiator was added and dissolved to obtain a curable resin composition. The obtained curable resin composition was cured by ultraviolet rays, and various physical properties were measured. The results are shown in Table 3.

Example 4 A curable resin composition was obtained according to Example 3, except that the urethane acrylate of Synthesis Example 3 was used instead of bisphenol A diglycidyl ether diacrylate. The obtained curable resin composition is ultraviolet-cured,
Various physical properties were measured. The results are shown in Table 3.

Comparative Example 5 Instead of the polytetramethylene glycol diacrylate of Synthesis Example 1, triethylene glycol diacrylate (3
EG-A A curable resin composition was obtained according to Example 3, except that Kyoeisha Chemical Co., Ltd. was used.
The obtained curable resin composition was cured by ultraviolet rays, and various physical properties were measured. The results are shown in Table 3.

Comparative Example 6 Curing was performed in the same manner as in Example 3 except that tripropylene glycol diacrylate (3PG-A manufactured by Kyoeisha Chemical Co., Ltd.) was used instead of polytetramethylene glycol diacrylate in Synthesis Example 1. A resin composition was obtained. The obtained curable resin composition was cured by ultraviolet rays, and various physical properties were measured. The results are shown in Table 3.

Comparative Example 7 Instead of the polytetramethylene glycol diacrylate of Synthesis Example 1, triethylene glycol diacrylate (3
EG-A A curable resin composition was obtained in the same manner as in Example 4, except that Kyoeisha Chemical Co., Ltd.) was used.
The obtained curable resin composition was cured by ultraviolet rays, and various physical properties were measured. The results are shown in Table 3.

Comparative Example 8 Curing was carried out in the same manner as in Example 4 except that tripropylene glycol diacrylate (3PG-A manufactured by Kyoeisha Chemical Co., Ltd.) was used instead of polytetramethylene glycol diacrylate in Synthesis Example 1. A resin composition was obtained. The obtained curable resin composition was cured by ultraviolet rays, and various physical properties were measured. The results are shown in Table 3.

COMPARATIVE EXPERIMENTS The polytetramethylene glycol diacrylates of Synthesis Examples 1 and 2, which are reactive diluents, were used alone at 25.degree.
And the curability were compared. The results are shown in Table-4. Table 4 shows that the compound of Synthesis Example 1 (average molecular weight 3
58, n average = 3.2) is clearly superior to the compound of Synthesis Example 2 (molecular weight: 758, n average = 8.8) in dilutability and curability.

Test Method Viscosity: The prepared sample was immersed in a thermostat at 25 ° C. for 6 hours, and immediately thereafter, the viscosity was measured using a B-type viscometer. Curability: The curable resin composition is coated on a glass plate with an applicator so as to have a thickness of 50 μm, and 80 w /
Irradiation with ultraviolet light was performed using a high-pressure mercury lamp of 10 cm. The conveyor speed was 6 m / min and the irradiation distance was 10 cm. The curability was compared by the number of irradiations until the tack disappeared. Hardness: The curable resin composition was poured into a cylindrical mold having a diameter of 28 mm and a thickness of 5 mm, and irradiated with ultraviolet rays 5 times each on the front and back sides under the same conditions as in the case of the curability test. Obtained. The hardness of the cured product was measured with a Shore D hardness meter.

Water absorption: A cured product prepared for hardness measurement was immersed in warm water at 60 ° C. for one week, and the weight increase after immersion relative to before immersion was expressed in percentage. Flexibility: The curable resin composition was coated on a glass plate with an applicator so as to have a thickness of 100 μm, and irradiated with ultraviolet rays 5 times under the same conditions as in the curability test. The obtained film was peeled off from the glass plate, and the film was cut into a strip having a length of 10 cm and a width of 2 cm. The test piece was bent along the outer periphery of an iron cylinder using a mandrel tester. The diameter of the cylinder was gradually reduced, and the comparison was made with the diameter of the cracked cylinder.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Table 4]

[0038]

[Table 5]

[0039]

The curable resin composition containing the polytetramethylene glycol diacrylate of the present invention as a reactive diluent is excellent in workability, curability and flexibility as is clear from the comprehensive evaluation in Table-5. As a resin composition having low water absorption and low skin irritation, it can be widely used in industries utilizing photocurable or thermosetting resins.

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Claims (1)

(57) [Claims] 1. A resin composition containing a curable resin, a photo or thermal polymerization initiator, and a reactive diluent, wherein the reactive diluent is polytetramethylene glycol diacrylate represented by the following general formula. Characteristic resin composition: In the formula, n is an integer, and the average value is 2 to 6.