JP5003853B2 - Radical curable resin composition - Google Patents

Description

  The present invention relates to a radical curable resin composition excellent in tensile strength, tensile elongation, low odor, and curing characteristics at room temperature.

  Urethane (meth) acrylate resin with (meth) acryloyl group introduced at the end has various physical properties such as mechanical strength and durability. Adhesive, sealing agent, coating agent, optical lens sheet, protective film It is widely used in various fields such as binders.

Examples of the urethane (meth) acrylate resin include a curable monomer (X) obtained by reacting a polyester polyol (a), a polyisocyanate (b), and an active hydrogen-containing acrylic monomer (c). In the photocurable resin composition comprising Y) and the photopolymerization initiator (Z), as the polyester polyol (a) for producing the prepolymer (X), 20 mol% or more of the polybasic acid component is contained. Consists of terephthalic acid and / or isophthalic acid, 20 mol% or more of the polyhydric alcohol component is neopentyl glycol, and 3 to 20 mol% is at least two in the molecule of a rosin compound of polyhydric alcohol having 3 or more valences. A polyester having a hydroxyl value of 20 to 230 KOHmg / g, composed of a partially esterified product in which the hydroxyl group remains. The photocurable resin composition, which comprises using a polyol, is disclosed (for example, see Patent Document 1.).
However, the photocurable resin as described above must be irradiated with ultraviolet rays using an ultraviolet light irradiation device such as a high-pressure mercury lamp, a metal halide lamp, a mercury lamp, or an ultraviolet LED lamp, and further heat-treated as necessary. It is known that the resin cannot be cured.

  On the other hand, in the fields of civil engineering, architecture, railways, roads, etc., a material that can be cured in a short time at room temperature is strongly demanded from the viewpoint of workability during construction on site.

As the civil engineering and building material that cures at room temperature in a short time, for example, a resin composition containing ether-based urethane methacrylate and methyl methacrylate is disclosed (for example, see Examples in Patent Document 2).
If it is based on the said resin composition, it is excellent in the hardening characteristic at normal temperature, and the workability | operativity at the time of on-site construction is favorable. Moreover, according to the said resin composition, it has the tensile strength and tensile elongation rate sufficient practically as a civil engineering building material.

  However, in fields such as road paving materials and road waterproofing materials, a material having a further tensile elongation rate in order to improve the step following ability to withstand cracks of the road due to the topography and weather of the land used. Is strongly demanded.

  However, in the resin composition using urethane methacrylate using an ether-based polyol such as propylene glycol as in the resin composition, it is possible to give a further tensile elongation while maintaining a certain degree of tensile strength. It was very difficult to design.

  Moreover, in the said field | area, the odor at the time of site construction becomes a problem, and the improvement of odor property is also calculated | required strongly. When methacrylic acid or the like is used as the ethylenically unsaturated monomer as in the case of the resin composition (refer to the example of Patent Document 2 in particular), odor is generated, so that the work environment on site is good. I can not say.

  As described above, although there is a strong demand from the industry for materials that improve tensile elongation while maintaining tensile strength, and have excellent low odor and curing properties at room temperature, they have not yet been found. Was the current situation.

JP 62-131006 A Japanese Patent Laid-Open No. 8-259643

  The problem to be solved by the present invention is to provide a radically curable resin composition that improves tensile elongation while maintaining tensile strength and is excellent in low odor and curing properties at room temperature.

While conducting research to solve the above-mentioned problems, the present inventors conducted diligent research focusing on the polyol used for the urethane (meth) acrylate resin and the unsaturated monomer used as the reactive diluent. .
In the course of research, the present inventors have found that when a urethane (meth) acrylate resin using a polyester polyol is used, the tensile elongation is slightly improved.
However, it has still been difficult to balance the tensile elongation and the tensile strength.
Therefore, the present inventors have advanced research on the polyester polyol and unsaturated monomer to be used.
As a result, when a radical curable resin composition containing a urethane (meth) acrylate resin using a relatively high molecular weight polyester polyol and a radical curable unsaturated monomer having a specific molecular weight is used, a tensile force The inventors have found that a radical curable resin composition that improves tensile elongation while maintaining strength, has low odor, and has excellent curing characteristics at room temperature can be obtained, and the present invention has been completed.
That is, the present invention may a polyester polyol number average molecular weight of 4 500 to 7000 (A), the polyisocyanate (B), is reacted isocyanate-terminated urethane prepolymer (C), with the hydroxyl group-containing ( It contains a urethane (meth) acrylate resin (1) obtained by reacting a (meth) acryloyl compound (D) and a radical curable unsaturated monomer (2) having a molecular weight of 200 to 500. A radical curable resin composition is provided.

  The radical curable resin composition of the present invention comprises a urethane (meth) acrylate resin (1) using a polyester polyol (A) having a specific number average molecular weight, and a radical curable unsaturated monomer having a specific molecular weight (2 )), A resin composition excellent in tensile strength, tensile elongation, low odor, and curing properties at room temperature can be obtained, so it is suitably used in the fields of civil engineering, architecture, railways, roads, etc. can do. Especially, it can be used especially suitably for uses, such as a road pavement material and a road waterproofing material.

  First, the urethane (meth) acrylate resin (1) used in the present invention will be described.

  The urethane (meth) acrylate resin (1) is obtained by reacting the polyester polyol (A) with the polyisocyanate (B) to obtain an isocyanate group-terminated urethane prepolymer (C), and then a hydroxyl group-containing (meth) acryloyl. It is obtained by reacting compound (D) and contains other additives as necessary.

  The polyester polyol (A) is obtained by reacting a polybasic acid and a polyhydric alcohol.

  Examples of the polybasic acid include citraconic acid, fumaric acid, itaconic acid, maleic acid, maleic anhydride, aconitic acid, tetrahydrophthalic acid, norbornene dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, glutaric acid, and 3-methyl-2. -Pentene diacid, 2-methyl-2-pentene diacid, succinic acid, sebacic acid, dodecanedioic acid, adipic acid, azelaic acid, 2-ethylhexanoic acid, cis-3-methyl-4-cyclohexene -Aliphatic polycarboxylic acids such as cis-1,2-dicarboxylic acid, cis-3-methyl-4-cyclohexene-cis-1,2-dicarboxylic acid anhydride, phthalic acid, isophthalic acid, terephthalic acid, Methyltetrahydrophthalic acid, methylhexahydrophthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, pyromellitic acid, trimethyl They include aromatic polycarboxylic acids such as lit acids, which may be used in combination alone or in combination. Among these, from the viewpoint of improving the tensile elongation, it is preferable to use a dicarboxylic acid, more preferably an aliphatic dicarboxylic acid, and particularly preferably adipic acid, succinic acid, and sebacic acid.

  The proportion of the aliphatic dicarboxylic acid in the polybasic acid component is preferably 20 to 100 mol%, more preferably 50 to 100 mol%, particularly preferably 90 to 100 mol, from the viewpoint of improving the tensile elongation. %.

  The polyhydric alcohol is not particularly limited as long as it has two or more hydroxyl groups. For example, ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,3-butanediol, , 4-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, Alicyclic diols such as dipropylene glycol and tripropylene glycol, cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,3-diol, cyclohexane-1,4-diol, cyclooctane- 1,4-diol, 2,5-norbornanediol, etc. Aromatic diols such as cyclic diol, p-xylene diol, 4,4′-methylenediphenol, 4,4′-dihydroxybiphenyl, 2,5-naphthalenediol, glycerin, trimethylolpropane, 1,2,6- Triols such as hexanetriol can be used, and these can be used alone or in combination of two or more. Among these, it is preferable to use an aliphatic diol from the viewpoint of imparting flexibility.

  The polyester polyol (A) is obtained by subjecting the polybasic acid and the polyhydric alcohol to a polycondensation reaction by a conventionally known method. As the polycondensation reaction, for example, the polybasic acid and the polyhydric alcohol are charged into a reaction vessel, and if necessary, a high boiling point solvent such as xylene and an esterification catalyst are added, and dehydration condensation is performed. And a method of allowing the chemical reaction to proceed. The reaction temperature of the polycondensation reaction is 140 to 240 ° C., preferably 170 to 230 ° C., and the reaction time is 10 to 25 hours, preferably 15 to 23 hours.

  The esterification catalyst is not particularly limited, but is a mineral acid such as sulfuric acid, hydrochloric acid or phosphoric acid, arenesulfonic acid such as benzenesulfonic acid or p-toluenesulfonic acid, alkanesulfonic acid such as methanesulfonic acid or ethanesulfonic acid. Acid, tin tetraethylate, butyltin malate, dimethyltin oxide, dibutyltin oxide, dioctyltin oxide and other tin compounds, tetraisopropyl titanate, tetra-n-butyl titanate, tetra-2-ethylhexyl titanate, titanium tetrachloride, etc. Compounds, zinc compounds such as zinc acetate, and the like can be used.

  The amount of the esterification catalyst used is preferably 0.001 to 0.1% by mass, and 0.001 to 0.05% by mass with respect to the total mass of the polybasic acid and the polyhydric alcohol. It is more preferable that

  As the polyester polyol (A) obtained by the reaction, a radical curable resin composition having a good balance between tensile strength and tensile elongation can be obtained by using a polyester polyol (A) having a number average molecular weight of 2500 to 7000. it can. Especially, as a number average molecular weight of the said polyester polyol from a viewpoint which can improve tensile strength and a tensile elongation rate, 3000-6500 are more preferable, and 4500-6500 are especially preferable. When the number average molecular weight of the polyester polyol is less than 2500, particularly, the tensile elongation is not sufficient, and when it exceeds 7000, gelation easily occurs due to an increase in viscosity, and the production stability is remarkably deteriorated. There is. In addition, the said number average molecular weight shows the value calculated | required by the gel permeation chromatography method (GPC method) which uses polystyrene as a molecular weight standard.

  Moreover, as said polyester polyol (A), it is more preferable that an acid value is 0.0-1.0 mgKOH / g from a viewpoint which can improve a tensile physical property more, and it is 0.20-0.80 mgKOH / g. It is particularly preferred. The acid value of the polyester polyol (A) is a value measured according to JIS K1557-5.

  The polyester polyol (A) preferably has a hydroxyl value of 10 to 200 mgKOH / g, more preferably 10 to 50 mgKOH / g, and more preferably 10 to 40 mgKOH / g from the viewpoint of further improving tensile physical properties. Particularly preferred is g. The hydroxyl value of the polyester polyol (A) is a value measured according to JIS K0070.

  Moreover, in this invention, as long as the effect of this invention is not impaired, you may use another polyol together with the said polyester polyol (A).

  As said other polyol, polyols, such as a polycarbonate polyol, a polybutadiene polyol, a polylactone polyol, a polyether polyol, can be used, for example.

  The polyisocyanate (B) is not particularly limited as long as it has two or more isocyanate groups in the molecule. For example, aromatic diisocyanates such as phenylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, hexa Aliphatic or aliphatic cyclic structure-containing diisocyanates such as methylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, xylylene diisocyanate, tolylene diisocyanate , Diphenylmethane diisocyanate, phenylene diisocyanate, poly Examples include aromatic polyisocyanates such as enylene polymethylene polyisocyanate, formalin condensate of methylenediphenyl disissocyanate, and carbodiimide modification of 4,4′-diphenylmethane diisocyanate. These may be used alone or in combination of two or more. Can be used in combination. Among these, it is preferable to use diisocyanate from the viewpoint of tensile properties and reactivity.

  Examples of the hydroxyl group-containing (meth) acryloyl compound (D) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like. Hydroxyl group-containing (meth) acrylic acid alkyl ester, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, and the like. These can be used alone or in combination of two or more. Among these, it is preferable to use a hydroxyl group-containing methacrylic acid alkyl ester, and it is particularly preferable to use 2-hydroxyethyl methacrylate from the viewpoint of further improving the curing characteristics and skin irritation at room temperature.

  Next, the manufacturing method of the said urethane (meth) acrylate resin (1) is demonstrated.

  The urethane (meth) acrylate resin (1) is obtained by reacting the polyester polyol (A) with the polyisocyanate (B) to obtain an isocyanate group-terminated urethane prepolymer (C), and then the hydroxyl group-containing (meth). It is obtained by reacting the acryloyl compound (D).

  In the reaction between the polyester polyol (A) and the polyisocyanate (B), the equivalent ratio [isocyanate group / hydroxyl group] of the hydroxyl group of the polyester polyol (A) and the isocyanate group of the polyisocyanate (B) is 2. It is preferably carried out in the range of 2 / 1.0 to 1.8 / 1.0, and preferably in the range of 2.1 / 1.0 to 1.9 / 1.0. The reaction between the polyester polyol (A) and the polyisocyanate (B) is preferably carried out under a condition of 50 to 100 ° C. for about 30 minutes to 8 hours.

  The reaction between the isocyanate group-terminated urethane prepolymer (C) obtained by the reaction between the polyester polyol (A) and the polyisocyanate (B) and the hydroxyl group-containing (meth) acryloyl compound (D) Equivalent ratio [residual isocyanate group / hydroxyl group] of the residual isocyanate group of the group-terminated urethane prepolymer and the hydroxyl group of the hydroxyl group-containing (meth) acryloyl compound is in the range of 0.8 / 1.0 to 1.2 / 1.0. It is preferable that

Moreover, as said urethane (meth) acrylate resin (1), it is preferable that all the terminal parts are (meth) acryloyl groups derived from the said hydroxyl-containing (meth) acryloyl compound, and an isocyanate group remains substantially. Preferably not.
The reaction between the isocyanate group-terminated urethane prepolymer (C) and the hydroxyl group-containing (meth) acryloyl compound (D) is preferably carried out at a temperature of 50 to 120 ° C. for about 30 minutes to 5 hours.

  Moreover, when manufacturing the said urethane (meth) acrylate resin (1), you may use a tertiary amine catalyst and an organometallic catalyst as needed.

  The urethane (meth) acrylate resin (1) may contain other additives such as a polymerization inhibitor, if necessary.

  Examples of the polymerization inhibitor include trihydroquinone, toluhydroquinone, 14-naphthoquinone, parabenzoquinone, hydroquinone, benzoquinone, hydroquinone monomethyl ether, p-tert-butylcatechol, 2,6-di-tert-butyl-4-methylphenol. These may be used alone or in combination of two or more. The polymerization inhibitor is used in an amount of 0.005 to 0.1 weight with respect to the total mass of the polyester polyol (A), the polyisocyanate (B), and the hydroxyl group-containing (meth) acryloyl compound (D). %, And more preferably 0.01 to 0.1% by weight.

  The number average molecular weight of the urethane (meth) acrylate resin (1) obtained as described above is preferably 2000 to 8000, more preferably 3000 to 7000, from the viewpoint of tensile physical properties and the like. In addition, the said number average molecular weight shows the value calculated | required by the gel permeation chromatography method (GPC method) which uses polystyrene as a molecular weight standard.

  Next, the radical curable unsaturated monomer (2) having a molecular weight of 200 to 500 used in the present invention will be described.

  As the radical curable unsaturated monomer (2), a monomer having one (meth) acryloyl group is preferably used. For example, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentenyl ( (Meth) acrylate, tris (2-hydroxyethyl) isocyanuric acrylate, phenoxyethyl (meth) acrylate and the like can be mentioned, and these can be used alone or in combination of two or more. Among these, those having a molecular weight of 200 to 400 are more preferable. From the viewpoint of odor and safety, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, phenoxyethyl (meta ) Acrylate is more preferably used, and dicyclopentenyloxyethyl methacrylate, dicyclopentenyl methacrylate, and phenoxyethyl methacrylate are particularly preferably used from the viewpoint of further improving the curing properties and skin irritation at room temperature.

Moreover, when the thing except said molecular weight is used as said radically curable unsaturated monomer (2), low odor property and tensile physical property do not become enough.
In addition, the molecular weight of the said radical curable unsaturated monomer (2) shows the value calculated from structural formula.

  Moreover, the use rate of the said urethane (meth) acrylate resin (1) in the said radical curable resin composition and the low odor unsaturated monomer (2) which has the molecular weight of said 160-1000 is tensile strength and tensile elongation. From the viewpoint of further improving the rate, (1) / (2) = 20/80 to 70/30 is preferable, 20/80 to 50/50 is more preferable, and 20/80 to 40/60. It is particularly preferred that

  Moreover, in the radical curable resin composition of this invention, it is preferable to further contain the hardening | curing agent (3) and the hardening accelerator (4) from a viewpoint which can improve the hardening characteristic in normal temperature more.

  Examples of the curing agent (3) include organic peroxides such as diacyl peroxides, peroxyesters, hydroperoxides, dialkyl peroxides, ketone peroxides, peroxyketals, alkyls. Perester-based, percarbonate-based and other known ones can be used and are appropriately selected according to curing conditions and the like.

  As a usage-amount of the said hardening | curing agent (3), 0.5-10 mass% with respect to the total mass of the said urethane (meth) acrylate resin (1) and the said radical-curable unsaturated monomer (2), Preferably, it is 1-5 mass%.

  The curing accelerator (4) is a substance having an action of decomposing the organic peroxide of the curing agent (3) by a redox reaction and facilitating generation of active radicals. For example, cobalt naphthenate and cobalt octylate. Metal soaps such as zinc octylate, vanadium octylate, copper naphthenate, barium naphthenate, metal chelates such as vanadium acetyl acetate, cobalt acetyl acetate, iron acetylacetonate, aniline, N, N-dimethylaniline, N , N-diethylaniline, p-toluidine, N, N-dimethyl-p-toluidine, N, N-dimethyl-p-toluidine ethylene oxide adduct, N, N-bis (2-hydroxyethyl) -p-toluidine 4- (N, N-dimethylamino) benzaldehyde, 4- [N, N-bis (2-hydro) Xylethyl) amino] benzaldehyde, 4- (N-methyl-N-hydroxyethylamino) benzaldehyde, N, N-bis (2-hydroxypropyl) -p-toluidine, N-ethyl-m-toluidine, triethanolamine, m N, N-substituted anilines such as toluidine, diethylenetriamine, pyridine, phenylmorpholine, piperidine, N, N-bis (hydroxyethyl) aniline, diethanolaniline, N, N-substituted-p-toluidine, 4- (N, Examples include amines such as N-substituted amino) benzaldehyde, which can be used alone or in combination of two or more.

  As the usage-amount of the said hardening accelerator (4), it is 0.05-5 mass% with respect to the total mass of the said urethane (meth) acrylate resin (1) and the said radical-curable unsaturated monomer (2). Preferably, it is 0.5 to 3% by mass.

  In addition to the above, the radical curable resin composition of the present invention includes various additives such as fillers, ultraviolet absorbers, pigments, thickeners, low shrinkage agents, anti-aging agents, plasticizers, bones Materials, flame retardants, stabilizers, reinforcing materials, etc. may be used.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited only to these examples.
Further, in the present invention, unless otherwise specified, “part” is “part by mass” and “%” is “mass%”.

[Synthesis Example 1]
<Synthesis of polyester polyol (A-1)>
A four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser is charged with 531 parts of adipic acid and 469 parts of 3-methylpentanediol, and as an esterification catalyst for the total charged amount. 0.003% by mass of tetraisopropyl titanate was added and reacted at 220 ° C. for 20 hours to obtain a polyester polyol (A-1). The polyester polyol (A-1) obtained had an acid value of 0.5 mgKOH / g, a hydroxyl value of 37 mgKOH / g, and a number average molecular weight of 3000.

[Synthesis Example 2]
<Synthesis of polyester polyol (A-2)>
A four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser was charged with 539 parts of adipic acid and 461 parts of 3-methylpentanediol, and as an esterification catalyst for the total amount charged. 0.003% by mass of tetraisopropyl titanate was added and reacted at 220 ° C. for 20 hours to obtain a polyester polyol (A-2). The polyester polyol (A-2) obtained had an acid value of 0.5 mgKOH / g, a hydroxyl value of 22.6 mgKOH / g, and a number average molecular weight of 5000.

[Synthesis Example 3]
<Synthesis of polyester polyol (A-3)>
A four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser was charged with 541 parts of adipic acid and 459 parts of 3-methylpentanediol, and as an esterification catalyst for the total charged amount. 0.003% by mass of tetraisopropyl titanate was added and reacted at 220 ° C. for 20 hours to obtain a polyester polyol (A-3). The polyester polyol (A-3) obtained had an acid value of 0.5 mgKOH / g, a hydroxyl value of 19 mgKOH / g, and a number average molecular weight of 6000.

[Synthesis Example 4]
<Synthesis of urethane methacrylate resin (1-1)>
Polyester polyol obtained in Synthesis Example 1 with 122 parts of tolylene diisocyanate and 28 parts of isophorone diisocyanate in a 1 liter four-necked flask equipped with a thermometer, stirrer, inert gas inlet, air inlet and reflux condenser. A-1) 2,000 parts were charged and reacted at 80 ° C. for 3 hours in a nitrogen atmosphere. The NCO% was 1.60, and the mixture was cooled to 60 ° C. Then, 130 parts of 2-hydroxyethyl methacrylate was added, and the mixture was further reacted at 90 ° C for 3 hours. After confirming that NCO% was 0.1% or less, 0.05% by mass of toluhydroquinone and 0.025% by mass of tertiary butylcatechol were added to the total charge, and urethane methacrylate resin (1- 1) was obtained.

[Synthesis Example 5]
<Synthesis of urethane methacrylate resin (1-2)>
Polyester polyol obtained in Synthesis Example 2 with 120 parts of tolylene diisocyanate and 27 parts of isophorone diisocyanate in a 1 liter four-necked flask equipped with a thermometer, stirrer, inert gas inlet, air inlet and reflux condenser. A-2) 2,000 parts were charged and reacted at 80 ° C. for 3 hours in a nitrogen atmosphere. NCO% became 1.59, it cooled to 60 degreeC, 129 parts of 2-hydroxyethyl methacrylate was then added, and also it was made to react at 90 degreeC for 3 hours. After confirming that NCO% was 0.1% or less, 0.05% by mass of toluhydroquinone and 0.025% by mass of tertiary butylcatechol were added to the total charge, and urethane methacrylate resin (1- 2) was obtained.

[Synthesis Example 6]
<Synthesis of urethane methacrylate resin (1-3)>
Into a 1 liter four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet, an air inlet and a reflux condenser, 118 parts of tolylene diisocyanate, 26 parts of isophorone diisocyanate and the polyester polyol obtained in Synthesis Example 3 ( A-3) 2,000 parts were charged and reacted at 80 ° C. for 3 hours in a nitrogen atmosphere. NCO% became 1.64, it cooled to 60 degreeC, 129 parts of 2-hydroxyethyl methacrylate was then added, and also it was made to react at 90 degreeC for 3 hours. After confirming that NCO% was 0.1% or less, 0.05% by mass of toluhydroquinone and 0.025% by mass of tertiary butylcatechol were added to the total charge, and urethane methacrylate resin (1- 3) was obtained.

[Comparative Synthesis Example 1]
<Synthesis of urethane methacrylate resin (1-4)>
In a 1 liter four-necked flask equipped with a thermometer, stirrer, inert gas inlet, air inlet and reflux condenser, 500.5 parts of diphenylmethane diisocyanate, 76 parts of propylene glycol, and 7.0 parts of dibutyltin laurate The mixture was charged and stirred at 60 ° C. for 4 hours. Thereafter, 130 parts of 2-hydroxyethyl methacrylate was stirred while dropping over 2 hours, and stirring was continued for 5 hours after the completion of dropping. Then, it cooled and the urethane methacrylate resin (1-4) was obtained.

[Comparative Synthesis Example 2]
<Synthesis of epoxy methacrylate resin (x-1)>
99 parts of Epicoat 828 (epoxy resin, manufactured by Yuka Shell KK, epoxy equivalent 188) on a 1 liter four-necked flask equipped with a thermometer, stirrer, inert gas inlet, air inlet and reflux condenser SR-16H (Sakamoto Yakuhin Kogyo Co., Ltd., 1,6-hexanediol diglycidyl ether, epoxy equivalent 156) 78 parts, methacrylic acid 86 parts, tris (dimethylaminomethyl) phenol 0.3 part, hydroquinone 03 parts, 48 parts of methyl methacrylate were charged, and the reaction was terminated at 90 ° C. for 10 hours while blowing air. When the acid value reached 10 mg KOH / g, the reaction was terminated, and 114 parts of methyl methacrylate was added to add epoxy methacrylate resin (x-1 )

[ Reference Example 1]
60 parts of the urethane methacrylate resin (1-1) obtained in Synthesis Example 4 was dissolved in 40 parts of phenoxyethyl methacrylate to obtain a radical curable resin composition.
To 100 parts of the radical curable resin composition, 0.4 part of 6% cobalt naphthenate, 0.4 part of dimethyl paratoluidine 2 ethylene oxide adduct, and 40% suspension of benzoyl peroxide (Nyper NS, NOF ( 2 parts) were added and mixed, and the time (curing time) until gelation was measured was 17 minutes (25 ° C.).

[Examples 1 and 2 , Comparative Example 1]
Radical curability in the same manner as in Reference Example 1 except that the type and amount of urethane methacrylate resin and / or epoxy methacrylate resin used and the type and amount of radical curable unsaturated monomer were changed as shown in Table 1. A resin composition was obtained. Similarly to Reference Example 1, with respect to 100 parts of the obtained radical curable resin composition, 0,4 parts of 6% cobalt naphthenate, 0.4 parts of dimethyl paratoluidine 2 ethylene oxide adduct, benzoyl peroxide, respectively. 2 parts of 40% suspension (Nyper NS, manufactured by NOF Corporation) were added and mixed, and the curing time was measured (25 ° C.).

[Measurement method of number average molecular weight]
The number average molecular weight of the polyester polyol used in the synthesis example was measured as follows.
It should be noted that the number average molecular weight of the urethane methacrylate resin used in Examples and Comparative Examples is also measured in the same manner as described below.
(Measurement equipment and conditions)
Tosoh Co., Ltd. integrated GPC device: HLC-8220GPC
Detector: RI (Suggested refractometer)
Column: TSK-gel G5000HxL (7.8 × 300 mm) × 1
G4000HxL (7.8 × 300mm) × 1
G3000HxL (7.8 × 300mm) × 1
G2000HxL (7.8 × 300mm) × 1
Mobile phase: THF
Flow rate: 1.0 mL / min
Set temperature: 40 ° C
Injection volume: 100 μL (sample concentration: 0.4%)
Measures the weight average molecular weight in terms of polystyrene (*).
* Polystyrene: TSK standard polystyrene manufactured by Tosoh Corporation

[Measurement method of tensile strength and tensile elongation test]
A mold release agent was applied to two 300 mm × 300 mm × 3 mm glass plates, and a 3 mm spacer was sandwiched between the glass plates to form a mold. After adding 6% cobalt naphthenate, dimethylparatoluidine 2 ethylene oxide adduct, and 40% suspension of benzoyl peroxide (Niper NS, manufactured by NOF Corporation) to the mold, it was obtained in Examples and Comparative Examples. The radical curable resin composition thus obtained was degassed under reduced pressure and then poured and cured at room temperature (25 ° C.) (the blending composition is the same as in Examples and Comparative Examples). This was cured by curing at 25 ° C. for 24 hours and at 80 ° C. for 5 hours. A test body having a thickness of 2 mm was prepared from the cast plate and used as a test body. The specimen was measured according to the JIS-K-7113 tensile test method. The measurement temperature was 25 ° C. and the room temperature physical properties were evaluated.

[Evaluation method of low odor]
The low odor evaluation method was measured as follows.
The curable resin compositions obtained in Examples and Comparative Examples were sniffed three times by five people,
“◯”: The unpleasant odor was not 5 or 3 times.
“×”: An unpleasant smell was once or even once.

Claims (6)

And polyester polyol (A) a number average molecular weight of 4 500 to 7000, with a polyisocyanate (B), reacted to obtain an isocyanate group-terminated urethane prepolymer (C), the product with the hydroxyl group-containing (meth) acryloyl compound (D ), A urethane (meth) acrylate resin (1) obtained by reaction, and a radically polymerizable unsaturated monomer (2) having a molecular weight of 200 to 500. Composition. The mass ratio of the urethane (meth) acrylate resin (1) and the radical polymerizable unsaturated monomer (2) in the radical curable resin composition is (1) / (2) = 20 / 80- The radical curable resin composition of Claim 1 which is 70/30. The polyester polyol (A) has a number average molecular weight of 4500 to 6500, and the urethane (meth) acrylate resin (1) in the radical curable resin composition and the radical polymerizable unsaturated monomer (2 The radical curable resin composition according to claim 1, wherein a mass ratio of (1) / (2) = 20/80 to 50/50. The radical curable resin composition according to claim 1, wherein the polyester polyol (A) contains an aliphatic dicarboxylic acid as a polybasic acid component. The radical curable resin composition according to claim 1, wherein the radical polymerizable unsaturated monomer (2) is a (meth) acryloyl compound having one (meth) acryloyl group. The radical polymerizable unsaturated monomer (2) is at least one selected from the group consisting of phenoxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate and dicyclopentenyl (meth) acrylate. The radical curable resin composition according to claim 1.