JP2000239328A - Unsaturated polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition having low toxicity, in the case of providing a curable resin composition, having excellent curing properties, strength at break, elongation ratio, useful as a coating agent for various substrates, by making the composition include an unsaturated polyester resin and an acrylic acid polymer ester of alcohol. SOLUTION: This composition comprises (A) an unsaturated polyester resin having excellent 3,000-30,000 weight-average molecular weight, preferably containing a cyclopentadiene-based unit, etc., as a condensation component and (B) an acrylic acid polymer ester of alcohol (preferably neopentyl glycol acrylic acid polymer ester, etc.). The composition is preferably used as a curing type resin composition curable by active energy rays. In this case, the use of a radical generation type photopolymerization initiator such as benzyldimethylketal is required. The blending ratio of the components A:B:C is preferably 100:40-150:1-10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unsaturated polyester resin composition having high safety and excellent curability, breaking strength and elongation.

[0002]

2. Description of the Related Art Unsaturated polyester resins containing a polyhydric alcohol allyl ether component, dicyclopentadiene, etc. have been conventionally used because they have an air-drying property, are preferably glossy and have a firm feeling, and give a beautiful finish. As a curable resin composition, it is used in general (for woodwork) paints, sealing materials, adhesives, molded products, and the like. In such applications, as described above, the unsaturated polyester resin in which a polyhydric alcohol allyl ether component, cyclopentadiene, dicyclopentadiene, or the like is introduced into the unsaturated polyester resin includes a crosslinking monomer, a curing aid, In the case of electron beam curing, it is essential to further incorporate an initiator, etc., and in fact, styrene is frequently used as the crosslinkable monomer.

[0003]

However, such styrene has the drawback that its curability is very slow, and has a high volatility and a strong odor, which may adversely affect the human body. It is necessary to pay attention to the need for a crosslinkable monomer with low toxicity, convenient handling, and excellent curability, as well as styrene in terms of physical properties such as breaking strength and elongation of the coating film. It is preferable to obtain more excellent effects, and in particular, a crosslinkable monomer that improves the breaking strength of a coating film is strongly desired.

[0004]

The inventors of the present invention have conducted intensive studies, and as a result, have found that an unsaturated polyester resin composition comprising an unsaturated polyester resin (A) and an acrylic acid polymer ester (B) is The inventors have found that the above objects have been achieved, and have completed the present invention.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The unsaturated polyester resin (A) used in the present invention is not particularly limited, but preferably has a molecular weight of 3,000 to 3,
0000 (preferably 4000 to 25000) unsaturated polyester resin is desirable. The unsaturated polyester resin is usually a condensation product of a polyhydric alcohol and an unsaturated polybasic acid (where necessary, a saturated polybasic acid is used in combination). Examples of the unsaturated polybasic acid include maleic anhydride, Maleic acid, fumaric acid, itaconic anhydride, itaconic acid and the like, and as the saturated polybasic acid, phthalic anhydride, phthalic acid,
Terephthalic acid, isophthalic acid, heptic acid, adipic acid,
Tetrahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 6-methyl-4-
And cyclohexene-1,2,3 tricarboxylic anhydride.

Examples of the polyhydric alcohol condensed with the unsaturated polybasic acid include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, hydrogenated bisphenol A, bisphenol A dioxypropoxy ether, Bisphenol A dipolyoxypropoxy ether, bisphenol A dioxyethoxy ether, bisphenol A dipolyoxyethoxy ether, 1,9-
Nonanediol, polypropylene glycol, polyethylene glycol, polytetramethylene glycol, 1,
3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, 2,
Examples thereof include 2,4-trimethyl-1,3-pentane-diol, neopentyl glycol, trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, and cyclohexanedimethanol.

In the present invention, the unsaturated polyester resin (A) preferably contains at least one selected from the group consisting of a cyclopentadiene unit, a dicyclopentadiene-based unit and a polyhydric alcohol allyl ether unit, Such cyclopentadiene units and dicyclopentadiene-based units are cyclopentadiene,
Dicyclopentadiene, and further derivatives thereof, include tricyclodecenyl maleate, tricyclodecenyl fumarate, tricyclodecenyl adipate, tricyclodecenyl phthalate. , Tricyclodecenyl isophthalate, tricyclodecenyl trimellitate, ethylene glycol tricyclodecenyl ether, diethylene glycol tricyclodecenyl ether, propylene glycol tricyclodecenyl ether, 1,4-butanediol tricyclode Cenyl ether, 1,6-hexanediol tricyclodecenyl ether, neopentyl glycol tricyclodecenyl ether, glycerin tricyclodecenyl ether, trimethylolpropane tricyclodecenyl ether, hydroxylated dicyclopenta And the polyhydric alcohol allyl ether unit, specifically, pentaerythritol triallyl ether, trimethylolpropane diallyl ether, glycerin monoallyl ether, trimethylolethane diallyl ether, glycerin diallyl ether, and the like. Are ethers containing at least one hydroxyl group in the molecule.

The proportion of at least one unit selected from the group consisting of cyclopentadiene-based units, dicyclopentadiene-based units, and polyhydric alcohol allyl ether units in the component (A) is determined according to the unsaturated polyester resin composition of the present invention. Is a curable resin composition that is cured by an active energy ray, the content is preferably 2 to 40 mol% with respect to the polybasic acid component, and if the ratio is less than 2 mol%, sufficient air drying cannot be obtained. On the other hand, if it exceeds 40 mol%, the curability is reduced. In the case of a cyclopentadiene-based unit or a dicyclopentadiene-based unit, it is more preferably present in an amount of 15 to 30 mol%. Further, in the case of a polyhydric alcohol allyl ether unit, it is more preferable to be present in an amount of 10 to 30 mol%.

When the unsaturated polyester resin composition of the present invention is cured into a curable resin composition at room temperature or by heating, the content is preferably 10 to 50 mol% based on the polybasic acid component. If the content is less than 10 mol%, sufficient air-drying properties cannot be obtained, and if it exceeds 50 mol%, the quick-drying property decreases. In the case of a cyclopentadiene-based unit or a dicyclopentadiene-based unit, it is more preferably present in an amount of 20 to 50 mol%. Further, in the case of a polyhydric alcohol allyl ether unit, it is more preferable to be present in an amount of 10 to 40 mol%. In addition, the said content mol% is 50 mol% in each ratio with respect to 1 mol of polybasic acid components.
Means that 0.5 mol is blended with respect to 1 mol of the polybasic acid component.

[0010] The cyclopentadiene-based unit or dicyclopentadiene-based unit is an unsaturated polyester resin (A).
In order to introduce the compound, at least one of cyclopentadiene, dicyclopentadiene and derivatives thereof is basically used.
The seed is charged together with the polybasic acid to carry out the condensation reaction.However, when the cyclopentadiene-based unit or dicyclopentadiene-based unit is present in the main chain of the unsaturated polyester resin rather than at the terminal of the unsaturated polyester resin, it is supplied to the paint or the like. In this case, the paint properties tend to be excellent, and therefore, in order to produce such a resin, it is desirable that at least one of cyclopentadiene, dicyclopentadiene, and their derivatives be charged at the beginning of condensation. The introduction of the polyhydric alcohol allyl ether unit into the unsaturated polyester resin may be performed in the same manner as in the case of the above-mentioned cyclopentadiene-based unit or dicyclopentadiene-based unit.

In the production of the unsaturated polyester resin (A), the above components may be subjected to a condensation or addition reaction in an inert gas atmosphere at a temperature of about 150 to 250 ° C. according to a conventional method. The unsaturated polyester resin (A) thus obtained usually has an acid value of about 10 to 30 KOH mg / g, and preferably has an acid value of 10 to 30 KOH mg / g by promoting esterification.
It is preferably in the range of about 20 KOH mg / g, and the weight average molecular weight of the unsaturated polyester resin (A) is preferably 3,000 to 30,000 as described above, and more preferably 4,000 to 25,000. When the weight average molecular weight is less than 3000, the physical properties of the cured product are low, and the curability may be slow. On the contrary, when the weight average molecular weight exceeds 30,000, the viscosity becomes high and a large amount of diluent monomer is required, and the curing speed may be slow. is there.

The weight-average molecular weight is measured by gel permeation chromatography (GPC). For example, using a KF-806 column with a Shodex system (manufactured by Showa Denko KK), tetrahydrofuran is used as a solvent. And polystyrene as a standard.

The acrylic acid polymer ester (B) of alcohol used in the present invention includes, for example, acrylic acid of alcohol such as neopentyl alcohol, 1,4-hexanediol, 1,6-hexanediol, diethylene glycol and tetraethylene glycol. An ester containing at least a dimer of an acid, preferably an ester represented by the following general formula (1)
And (4) neopentyl glycol acrylate multimer ester, 1,4-butanediol acrylate multimer ester and 1,6-hexanediol acrylate multimer ester.

[0014] (However, n is an integer of 0 or more) Examples of the commercially available product include “Biscoat # 215D” (manufactured by Osaka Organic Chemical Industry Co., Ltd.). This is because in the above general formula, n = 0 is 25 to 30% by weight, and n = 1 to 5 is 7
It is a mixture of esters having a composition of 0 to 75% by weight.

[CH ₂ = CHCO _2- (CH ₂ CH ₂ CO ₂ ) _n ] _2- (CH ₂ ) ₄ ... (2) (n is an integer of 0 or more) VISCOAT # 195D "(manufactured by Osaka Organic Chemical Industry Co., Ltd.). This is because in the above general formula, n = 0 is 25 to 30% by weight, and n = 1 to 5 is 7
It is a mixture of esters having a composition of 0 to 75% by weight.

[CH ₂ = CHCO _2- (CH ₂ CH ₂ CO ₂ ) _n ] _2- (CH ₂ ) ₆ ... (3) (where n is an integer of 0 or more) VISCOAT # 230D "(manufactured by Osaka Organic Chemical Industry Co., Ltd.). This is because in the above general formula, n = 0 is 25 to 30% by weight, and n = 1 to 5 is 7
It is a mixture of esters having a composition of 0 to 75% by weight.

The acrylic acid polymer ester (B) of the above alcohol has extremely low volatility as compared with styrene.
It has less odor, less irritation of eyes, nose, throat, etc. by steam, and has excellent curability, so that the working environment for use is significantly improved.

When the unsaturated polyester resin composition of the present invention is used as a curable resin composition which is cured by an active energy ray, it is necessary to additionally use a radical-generating photopolymerization initiator (C). The initiator (C) is not particularly limited as long as it generates a radical by the action of light. Specific examples thereof include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, and diethoxyacetophenone. , 2-hydroxy-
2-methyl-1-phenylpropan-1-one, 1-
(4-Isopropylenephenyl) -2-hydroxy-2
-Methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) -phenyl (2-
(Hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4-
(Methylthio) phenyl] -2-morpholinopropane-
1, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether,
Benzoin isobutyl ether, benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenylsulfide, 3,3'-dimethyl-4-methoxybenzophenone, Thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone,
Camphorquinone, dibenzosuberone, 2-ethylanthraquinone, 4 ', 4 "-diethylisophthalophenone, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, α-acyloxime ester , Acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, 4- (2-hydroxyethoxy) phenyl-
(2-Hydroxy-2-propyl) ketone and the like, and triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler's ketone), 4,4'-diethylaminobenzophenone, 2- Dimethylaminoethylbenzoic acid, ethyl 4-dimethylaminobenzoate, ethyl (4-butoxy) ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4-diethyl Thioxanthone, 2,4-diisopropylthioxanthone and the like can be used in combination. Among these radical-generating photopolymerization initiators, benzyldimethylketal, 1-hydroxycyclohexylphenylketone, benzoylisopropylether, 4 (2-hydroxyethoxy) - phenyl (2-hydroxy-2-propyl) ketone, 2-
Hydroxy-2-methyl-1-phenylpropane-1-
On is preferably used.

The composition comprising (A) to (C) is not particularly limited with respect to the composition ratio, but in order to obtain the effects of the present invention efficiently, (A) :( B):
The compounding weight ratio of (C) is 100: 25-250: 0.2-
20 is preferable, and 100: 40 to 150: 1 to 1 is more preferable.
0 is preferred. If the content of (B) is less than the above range, the viscosity is increased and the workability is reduced. On the other hand, when (C) is too small, the curability is slow, and conversely, when it is too large, the curability is not improved and it is useless. In addition to the above (A) to (C), an antifoaming agent, a flame retardant, an antistatic agent, a plasticizer, and the like can be used in combination.

The method of curing the curable resin composition obtained by such a formulation is not particularly limited as long as it activates the above radical-generating photopolymerization initiator (C). Ultraviolet, near ultraviolet, infrared rays, X
Irradiation, active energy rays such as electron beams, proton rays, and neutron rays, and curing methods, and the like. The ultraviolet ray is mainly composed of light in the wavelength range of 150 to 450 nm, and includes a method of irradiating with a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, or the like.

When the unsaturated polyester resin composition of the present invention is used as a curable resin composition which cures at room temperature or by heating, the radical-generating photopolymerization initiator (C) is replaced by heat. What is necessary is just to use a radical generator (D). As such a radical generator (D),
Methyl ethyl ketone peroxide, cyclohexanone peroxide, cumene hydroperoxide, benzoyl peroxide, dicumyl peroxide, t-
Butyl perbenzoate and the like can be used.Co-octenoate, cobalt naphthenate, manganese octenoate, manganese naphthenate, various amine compounds and the like can be used in combination as these auxiliaries.Methyl ethyl ketone peroxide and octene are preferably used. Cobalt acid is used in combination.

The composition comprising (A), (B) and (D) is not particularly limited with respect to the composition ratio, but in order to obtain the effects of the present invention efficiently, (A):
(B): (D) compounding weight ratio of 100: 25 to 250:
1 to 20 are preferable, and 100: 40 to 150: 2 is more preferable.
To 10 are preferred. If the content of (B) is less than the above range, the viscosity is increased and the workability is reduced, and if the content is too large, the physical properties are poor. On the other hand, when (D) is too small, the curability is slow, and conversely, when it is excessive, the curability is not improved and it is useless. Also,
In addition to the above (A), (B) and (D), an antifoaming agent, a flame retardant, an antistatic agent, a plasticizer and the like can be used in combination.

The thus obtained unsaturated polyester resin composition (curable resin composition) of the present invention can be widely used as a coating agent (paint) for various substrates, a putty sealing agent, an adhesive and the like. Depending on the application, pigments (titanium white, titanium white,
Cyanine blue, Watching red, Bengala, Carbon black, Aniline black, Manganese blue, Iron black, Ultramarine blue, Hansa red, Chrome yellow, Chrome green, etc.), Filler (calcium carbonate, kaolin, clay, talc, mica, alumina) ,
Asbestos powder, finely divided silica, barium sulfate, lithopone,
Stone masonry, zinc stearate, perlite, etc.), leveling agents (silicone, cellulose acetate butyrate, surfactants, etc.), stabilizers, thermoplastic resins (high density, medium density, low density polyethylene, polypropylene, polybutene, Homopolymers such as polypentene, ethylene-propylene copolymer, nylon-6, nylon-
6,6 polyamide resin, vinyl chloride resin, nitrocellulose resin, vinylidene chloride resin, acrylic resin, acrylamide resin, styrene resin, vinyl ester resin, polyester resin, etc.), reinforcing agent ( Glass fiber, carbon fiber, etc.), anti-dripping agent (hydrogenated castor oil, fine silica, etc.), matting agent (fine silica,
Paraffin wax, etc.) and abrasives (zinc stearate, etc.) can also be blended. In this case, the amount of the pigment is 2 to 20% by weight, the amount of the filler is 2 to 50% by weight, the leveling agent Is 0.001 to 5% by weight,
The amount of the thermoplastic resin is 5 to 30% by weight, the amount of the anti-dripping agent is 1 to 5% by weight, the amount of the matting agent is 1 to 10% by weight, and the amount of the abrasive is 1 to 10% by weight. Is appropriately selected from the range. Further, as a diluent, it is also possible to add about 1 to 10% by weight of ethyl acetate, toluene, xylene, butanol, acetone, methyl isobutyl ketone, methyl ethyl ketone, cellosolves, diacetone alcohol and the like.

[0024]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, "%" and "parts"
Unless otherwise specified, it is based on weight. Unsaturated polyester resins (AI, A-II) were produced in the following manner. (A-I) A reactor equipped with a stirrer, a rectification tower, a nitrogen introducing tube, and a vacuum device was charged with 0.1 mol of trimethylolpropane diallyl ether, 1 mol of fumaric acid, and 1.1 mol of diethylene glycol. 3% and 0.02% of hydroquinone (polymerization inhibitor) were charged (the charged amounts were all based on the total amount of the condensed components), and after performing a condensation reaction at 200 ° C. for 5 hours while blowing nitrogen gas, 5 to 50 m
The reaction was continued for 1 hour at 150 ° C. and mHg, and the xylene was distilled off to obtain an acid value of 12 KOH mg / g and a weight average molecular weight of 9000.
(A-I) was obtained.

(A-II) Stirrer, rectification column, nitrogen inlet tube,
Dicyclopentadiene 0.1 was added to a reactor equipped with a vacuum device.
15 mol, 1 mol of fumaric acid and 50 ppm of cobalt acetate
After addition reaction was performed at 150 ° C. for 2 hours, 0.3 mol of ethylene glycol and 0.7 mol of diethylene glycol were charged, and 3% of xylene and 0.02% of hydroquinone (polymerization inhibitor) were charged (charged). After the condensation reaction was carried out at 210 ° C. for 5 hours while blowing nitrogen gas, 5 to 50 mm
The reaction was continued for 1 hour at 150 ° C. under Hg, xylene was distilled off, acid value 15 KOH mg / g, weight average molecular weight 1000
Thus, an unsaturated polyester resin (A-II) was obtained.

EXAMPLE 1 Neopentyl glycol acrylic acid polymer ester ("Biscoat # 215D", manufactured by Osaka Organic Chemical Industry Co., Ltd.) (B) 5 was added to 50 parts of the above unsaturated polyester resin (A-I).
0 parts, hydroquinone monomethyl ether 400pp
m, and 4 parts of benzyldimethyl ketal (“Irgacure 651”, manufactured by Ciba Geigy) as a radical-generating photopolymerization initiator (C) were added, and the viscosity was 7000 mPa
-The curable resin composition of s / 20 degreeC was obtained. The following evaluation was performed about the obtained hardening type resin composition.

(Odor) The obtained curable resin composition was treated with PE
The odor when applied on a T film with an applicator having a gap of 200 μm was evaluated as follows. ○: Almost no odor is felt. ×: Strong odor. (Curability) The obtained curable resin composition was applied on a PET film with an applicator having a gap of 200 μm,
20 cm was passed repeatedly under a high-pressure mercury lamp of mW at a speed of 4 m / min, and the number of passes until the surface tackiness was not recognized was examined. (Rupture strength, elongation)
It is applied on a T film with an applicator having a gap of 200 μm, and 20 cm under a high pressure mercury lamp of 80 mW is applied at 4 m / min.
3 times at a speed of 10 mm
× 50 mm, peeled from the PET film, and pulled by an autograph at a test distance of 20 mm and a test speed of 5 mm / min to obtain a breaking strength and an elongation at break [rupture with respect to the starting chuck distance (20 mm). Sometimes, the distance (mm) extending from the original length is indicated by (%). ] Was measured.

Example 2 In Example 1, neopentyl glycol acrylic acid polymer ester (“Biscoat # 215D”, manufactured by Osaka Organic Chemical Industry Co., Ltd.) (B) was used instead of 1,4-butanediol acrylic acid polymer ester ("Viscote # 195
D ", manufactured by Osaka Organic Chemical Industry Co., Ltd.) (B)
Performed in the same manner as in Example 1 to obtain a viscosity of 7,200 mPa · s / 2.
A curable resin composition at 0 ° C. was obtained and similarly evaluated.

Example 3 In Example 1, neopentyl glycol acrylic acid polymer ester ("Biscoat # 215D", manufactured by Osaka Organic Chemical Industry Co., Ltd.) (B) was used instead of 1,6-hexanediol acrylic acid polymer ester. ("Viscort # 230
D ", manufactured by Osaka Organic Chemical Industry Co., Ltd.) (B)
Performed in the same manner as in Example 1 to obtain a viscosity of 6,800 mPa · s / 2.
A curable resin composition at 0 ° C. was obtained and similarly evaluated.

Example 4 In Example 1, the unsaturated polyester resin (A-I)
Was carried out in the same manner as in Example 1 except that the unsaturated polyester resin (A-II) was used in place of
A curable resin composition of s / 20 ° C. was obtained and similarly evaluated.

Comparative Example 1 The procedure of Example 1 was repeated, except that styrene was used instead of neopentyl glycol acrylic acid polymer ester (“Biscoat # 215D”, manufactured by Osaka Organic Chemical Industry Co., Ltd.). A curable resin composition having a viscosity of 6700 mPa · s / 20 ° C. was obtained and similarly evaluated.

[0032]

Table 1 Odor Curability Breaking strength Elongation rate (kgf / mm ² ) (%) Example 1 5.7 5.0 〃 2 １ 4.7 〃 4.1 〃 3 １ 4.1. 1〃4 ○ 1 6.1 4.7 Comparative Example 1 × 3 3.5 4.1 The acrylic acid polymer ester of the alcohol used above had a boiling point and a flash point higher than that of styrene as shown below. But low in safety. Boiling point Flash point Styrene 145 ° C 31 ° C “Biscoat # 215D” 200 ° C or higher 146 ° C “Biscoat # 195D” 200 ° C or higher 150 ° C “Biscoat # 230D” 200 ° C or higher 174 ° C

[0033]

Since the unsaturated polyester resin composition of the present invention contains a specific crosslinkable monomer, it has no adverse effect on the human body. It has excellent breaking strength and elongation, and is useful as a coating agent (paint) for various substrates, a putty sealing agent, an adhesive, a molded product, and the like.

Continued on front page F-term (reference) 4H017 AA04 AB13 AC16 AC17 AD05 AD06 4J002 CF21W CF23W CF25W EH076 GH01 GJ01 GJ02 4J027 AB06 AB07 AB08 AB13 AB17 AB18 AJ01 BA07 CB03 CC03 CD01 CD08 CD09 4J038 FA121 FA122 FA151 KA1712 FA0211 4J040 ED121 ED141 FA141 JB02 JB07 KA13 LA01

Claims (6)

[Claims] 1. An unsaturated polyester resin composition comprising an unsaturated polyester resin (A) and an acrylic acid polymer ester (B) of an alcohol. 2. The acrylic acid multimeric ester of alcohol (B) is any of neopentyl glycol acrylic acid multimeric ester, 1,4-butanediol acrylic acid multimeric ester, and 1,6-hexanediol acrylic acid multimeric ester. The unsaturated polyester resin composition according to claim 1, wherein 3. The unsaturated polyester resin composition according to claim 1, wherein the unsaturated polyester resin (A) has a weight average molecular weight of 3,000 to 30,000. 4. The unsaturated polyester resin (A) is characterized in that at least one unit selected from the group consisting of cyclopentadiene-based units, dicyclopentadiene-based units and polyhydric alcohol allyl ether units is used as a condensation component. The unsaturated polyester resin composition according to any one of claims 1 to 3. 5. The unsaturated polyester resin composition according to claim 1, wherein the unsaturated polyester resin composition is a curable resin composition. 6. The unsaturated polyester resin composition according to claim 5, wherein the curable resin composition is cured by an active energy ray.