JP2007112985A - Radically curable resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radically curable resin composition capable of sufficiently suppressing shrinkage during curing without causing separation even after long-term passage and capable of providing a cured product (molded article) exhibiting high appearance while solving inconvenience such as crack or warp in molding. <P>SOLUTION: The radically curable resin composition comprises an oxazoline group-containing ethylenic polymer and a radically curable resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a radical curable resin composition. More specifically, for example, radical curing properties used in various applications other than FRP products such as bathtubs, septic tanks, vehicle components, electrical parts, pipes, molded products such as cast concrete, resin concrete, etc. The present invention relates to a resin composition.

The radical curable resin can be handled in a liquid state, has good workability, and the cured product has excellent performance in durability, drying property, strength, etc., and thus is suitably used for various applications. Yes. For example, bathtubs, septic tanks, parts for vehicles, electrical parts, pipes and other fiber reinforced plastics (FRP: Fiber Reinforced Plastics) products, resin concrete, gel coat, paint, putty, decorative boards, adhesives, WPC (Wood Plastic Combination), It is widely used in various fields such as casting materials; covering materials such as concrete, asphalt, mortar, steel plate, glass, and thermoplastics; covering materials for civil engineering and construction such as lining materials and coated flooring materials.

Among these uses, for example, when a radical curable resin is used as a raw material for molded products such as FRP products such as bathtubs, septic tanks, vehicle members, electrical components, pipes, cast molded products, and resin concrete, Due to the curing shrinkage of the radical curable resin, defects such as cracking and warping may occur during molding. Therefore, in order to overcome such problems, a method of mixing a thermoplastic polymer such as polystyrene with a radical curable resin as a low shrinkage agent (material) and curing the resulting resin composition is widely known. ing. For example, a styrene polymer obtained by stopping the polymerization of a monomer composition having a specified ratio of three components of a styrene, a (meth) acrylic acid ester and a polymerizable monomer having a carboxyl group at a specific polymerization rate. Low shrinkage for thermoplastic resin composed of a lactone polyester polyol resin synthesized from a technique used as a low shrinkage agent (for example, see Patent Document 1), polyhydric alcohol, polybasic acid or anhydride thereof and ε-caprolactone Low shrinkage agent (for example, obtained by copolymerizing a vinyl ester, an ethylenically unsaturated carboxylic acid, an ethylenically unsaturated carboxylic acid ester and an epoxy group-containing unsaturated compound) (for example, see Patent Document 2) Patent Document 3), a method using polystyrene having a specific number average molecular weight as a low shrinkage agent (for example, see Patent Document 4), and the like are disclosed. There.

However, many of these low shrinkage agents do not have sufficient dispersion stability when mixed with a radical curable resin. For example, when polystyrene is used, the obtained resin composition is separated over time. As a result, it becomes a factor causing a fatal defect in applications requiring a high appearance, such as a pattern due to agglomerates of the low shrinkage agent on the surface of the cured product after curing. Therefore, there is a demand for a technique that can provide a cured product with a high appearance while eliminating defects such as cracking and warping during molding.
Japanese Patent No. 3238586 (first page) Japanese Examined Patent Publication No. 6-76480 (first page) Japanese Patent Laid-Open No. 5-17546 (page 2) JP 11-172092 A (2nd page)

The present invention has been made in view of the above situation, and can sufficiently suppress shrinkage at the time of curing without separation even after a long period of time, and is free from defects such as cracking and warping at the time of molding. It aims at providing the radical curable resin composition which can give the hardened | cured material (molded article) which exhibits high appearance while eliminating.

As a result of various studies on the radical curable resin composition, the present inventors have used an oxazoline group-containing polymer as a low shrinkage agent, and if it contains this and a radical curable resin, the oxazoline group-containing polymer Found that the coalescence is excellent in dispersion stability in the radical curable resin, and that it does not separate even after a long period of time and can sufficiently suppress cure shrinkage. I was able to solve this problem. In such a resin composition, the oxazoline group-containing polymer is obtained by polymerizing an addition-polymerizable oxazoline and an addition-polymerizable monomer component that does not react with the oxazoline group, or a radical curable resin. Or at least one resin selected from the group consisting of unsaturated polyester resins, vinyl ester resins, polyester (meth) acrylates, urethane (meth) aclutes, acrylic syrups and polyether (meth) acrylates. It has been found that the effects of the invention can be fully exhibited. In addition, such resin compositions are useful as raw materials for various molded products in addition to FRP products such as bathtubs, septic tanks, vehicle members, electrical components, pipes, cast molded products, resin concrete, and the like. As a result, the present invention has been achieved.

That is, the present invention is a radical curable resin composition containing an oxazoline group-containing polymer and a radical curable resin.
The present invention is described in detail below.

Although the radical curable resin composition of this invention contains an oxazoline group containing polymer and radical curable resin, these each component can use 1 type (s) or 2 or more types, respectively. In addition, the said radical curable resin composition can contain other components mentioned later other than the said oxazoline group containing polymer and radical curable resin within the range which does not impair the effect of this invention.
In the radical curable resin composition, the mass ratio between the oxazoline group-containing polymer and the radical curable resin is 0.5 parts by mass with respect to 100 parts by mass of the radical curable resin, The upper limit is preferably 70 parts by mass. If it is less than 0.5 parts by mass, cracking or warping may occur during molding of the resulting resin composition, and sufficient anti-separation curing when other polymers are added to further reduce shrinkage May not be obtained. If it exceeds 70 parts by mass, the strength of the cured product obtained by curing the resin composition will be low, which may cause damage to the cured product due to external stress or impact. More preferably, the lower limit is 1 part by mass and the upper limit is 50 parts by mass.

In the radical curable resin composition, it is preferable that the lower limit of the weight average molecular weight is 10,000 and the upper limit is 500,000 as the oxazoline group-containing polymer. If it is less than 10,000, there is a possibility that problems that may occur at the time of molding cannot be sufficiently prevented, and if it exceeds 500,000, the viscosity becomes too high and may not be sufficiently mixed with the radical curable resin. is there. More preferably, the lower limit is 20000 and the upper limit is 400,000, and more preferably the lower limit is 50000 and the upper limit is 300,000.
The weight average molecular weight can be determined, for example, by using a gel permeation (GPC) apparatus. As GPC measurement conditions, for example, the following can be performed.

(GPC measurement conditions)
GPC measuring device: High-speed GPC device (trade name “HLC-8120 GPC”, manufactured by Tosoh Corporation)
Detector: Differential refractometer Column: TSK gel Super HM-H
TSK gel Super H-2000
Solvent: THF (tetrahydrofuran), flow rate 0.6 ml / min
Sample concentration: 0.5% by mass
Injection amount: 100 μl / time In addition, using a polystyrene oligomer (trade name “TSK Standard Polystyrene”, manufactured by Tosoh Corporation) as a standard sample, a calibration curve under the above GPC measurement conditions is prepared and determined.

Examples of the oxazoline group-containing polymer include a polymer obtained by polymerizing an addition polymerizable oxazoline and an addition polymerizable monomer that does not react with the oxazoline group (hereinafter also referred to as “polymer (A)”). Is preferred. That is, it is preferable to include a polymer obtained by polymerizing a monomer component having an addition polymerizable monomer that does not react with the oxazoline group together with the addition polymerizable oxazoline.
Examples of the addition polymerizable oxazoline in the polymer (A) include the following general formula (1);

(Wherein R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, a halogen atom, an aralkyl group, a phenyl group or a substituted phenyl group, and R ⁵ has an addition polymerizable unsaturated bond) A non-cyclic organic group), and one or more of these can be used.

Specific examples of the addition polymerizable oxazoline include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl- 2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like, and one or a mixture of two or more selected from these groups Can be used. Among these, 2-isopropenyl-2-oxazoline is preferable for the present invention, whereby the dispersion stability of the resin composition is more sufficiently improved and the separation of the resin composition can be more sufficiently suppressed. Moreover, it is also a suitable reason that it is industrially easy to obtain.
Thus, the form in which the oxazoline group-containing polymer is obtained by polymerizing a monomer component containing 2-isopropenyl-2-oxazoline and a monomer having an ethylenically unsaturated group is This is one of the preferred forms of the invention.

Examples of the addition polymerizable monomer that does not react with the oxazoline group include, for example, a monomer having a form in which R ⁵ is a group having an ethylenically unsaturated group among the monomers represented by the general formula (1). Or the following monomers etc. are mentioned, These 1 type (s) or 2 or more types can be used.
Methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic 2-ethylhexyl acid, methoxypolyethylene glycol (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate , Monoesterified product of (meth) acrylic acid and polyethylene glycol, 2-aminoethyl (meth) acrylate and salts thereof, caprolactone modified product of (meth) acrylic acid, (meth) acrylic acid-2,2,6 , 6-Tetramethylpiperidine, (meth) acrylic acid-1,2,2,6,6- (Meth) acrylic acid esters such as n-methylpiperidine; (meth) acrylic acid salts such as sodium (meth) acrylate, potassium (meth) acrylate and ammonium (meth) acrylate; unsaturated such as acrylonitrile and methacrylonitrile Nitriles; Unsaturated amides such as (meth) acrylamide, N-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide; Vinyl esters such as vinyl acetate and vinyl propionate; Methyl vinyl ether, ethyl vinyl ether, etc. Vinyl ethers; α-olefins such as ethylene and propylene; halogen-containing α, β-unsaturated aliphatic hydrocarbons such as vinyl chloride, vinylidene chloride and vinyl fluoride; α such as styrene, α-methylstyrene and sodium styrenesulfonate , Β-unsaturated Family hydrocarbons, and the like.
One or more of these monomers can be used as appropriate.
In particular, styrene is suitable as a monomer component other than the addition-polymerizable oxazoline from the viewpoint of compatibility or solubility in the radical curable resin. Thus, the radically curable resin composition containing the addition polymerizable monomer component which does not react with the addition polymerizable oxazoline and the oxazoline group (A) composed of styrene is also one of preferred embodiments of the present invention. It is.

The addition polymerizable oxazoline (addition polymerizable monomer component that does not react with the oxazoline group) in the polymer (A) is preferably 1 to 50% by mass with respect to 100% by mass of all monomer components. is there. When it is less than 1% by mass, there is a possibility that sufficient dispersion stability cannot be exhibited when the polymer (A) is mixed with the radical curable resin. When it exceeds 50% by mass, the storage stability of the molding material May not be sufficient. As said range, Preferably, it is 1.5-40 mass%, More preferably, a minimum is 2-30 mass%.

The polymer (A) can be obtained, for example, by polymerizing a monomer component containing an oxazoline group-containing monomer and an ethylenic monomer in the presence of a polymerization initiator. The polymerization reaction method is not particularly limited, and for example, it can be performed by a usual polymerization method such as solution polymerization, emulsion polymerization, suspension polymerization, precipitation polymerization or the like.
Although it does not specifically limit as said polymerization initiator and what is normally used may be used, An organic peroxide is suitable. Examples of the organic peroxide include ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, and acetylacetone peroxide; -Butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, 2- Hydroperoxides such as (4-methylcyclohexyl) -propane hydroperoxide; di-tert-butyl peroxide, tert-butyl group Ruperoxide, dicumyl peroxide, α, α′-bis (tert-butylperoxy) p-diisopropylbenzene, α, α′-bis (tert-butylperoxy) p-isopropylhexyne, 2,5-dimethyl Dialkyl peroxides such as -2,5-di (tert-butylperoxy) hexane and 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3;

tert-butyl peroxyacetate, tert-butyl peroxylaurate, tert-butyl peroxybenzoate, di-tert-butyl peroxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, tert-butylperoxyisopropyl carbonate, tert-butylperoxyisobutyrate, tert-butylperoxybivalate, tert-butylperoxyneodecanoate, cumylperoxyneodecanoate, tert-butylperoxy-2 -Ethylhexanoate, tert-butylperoxy-3,5,5-trimethylcyclohexanoate, tert-butylperoxybenzoate, tert-butylperoxymaleic acid, cumylperoxyoctoate peroxyesters such as tert-hexylperoxybivalate, tert-hexylperoxyneohexanoate, cumylperoxyneohexanoate; n-butyl-4,4-bis (tert-butylperoxy) valerate, 2,2-bis (tert-butylperoxy) butane, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (tert-butylperoxy) cyclohexane, Peroxyketals such as 2,2-bis (tert-butylperoxy) octane; acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,3,5-trimethyl Cyclohexanoyl peroxide Diacyl peroxides such as succinic acid peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-toluyl peroxide; di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, Di-n-propyl peroxydicarbonate, bis- (4-tert-butylcyclohexyl) peroxydicarbonate, dimyristyl peroxydicarbonate, di-methoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxy Butyl) peroxydicarbonate, peroxydicarbonates such as di-allylperoxydicarbonate; acetylcyclohexylsulfanyl peroxide, tert-butylperoxyallylcarb Other organic peroxides such as bonates can be mentioned. These may use only 1 type or may use 2 or more types together.

It does not specifically limit as a solvent used at the said superposition | polymerization process, What is necessary is just to use what is normally used. For example, alcohols such as methanol, ethanol, isopropyl alcohol, n-butanol, 2-butanol, ethylene glycol, diethylene glycol, propylene glycol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether; aromatics such as toluene, xylene, and benzene System solvents, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate and the like can also be used as appropriate.

Regarding the reaction conditions at the time of the said polymerization, it does not specifically limit as reaction temperature, For example, it is preferable that it is 50 degreeC or more, More preferably, it is 60-150 degreeC. Further, the reaction pressure is not particularly limited, and may be, for example, normal pressure (atmospheric pressure), reduced pressure, or increased pressure. In addition, it is suitable to set it as a normal pressure (atmospheric pressure) at the point which can superpose | polymerize simply and at low cost.

In the radical curable resin composition of the present invention, the radical curable resin is composed of a radical polymerizable oligomer and a polymerizable monomer.
Examples of the radical polymerizable oligomer include one or two of unsaturated polyester, vinyl ester, polyester (meth) acrylate, urethane (meth) aclute, (meth) acrylate polymer, and polyether (meth) acrylate. It is preferable that it is comprised from the above. Among them, it is particularly preferable to use an unsaturated polyester because it is excellent in various physical properties such as toughness, strength, durability, hot water resistance, and transparency.

As the radical polymerizable oligomer, it is preferable that the lower limit of the weight average molecular weight is 300 and the upper limit is 50000. If it is less than 300, the obtained cured product becomes extremely brittle, and cracks and the like are likely to occur due to external impact and stress. If it exceeds 50,000, a filler is blended, and a molding material for casting is obtained. When it is prepared, there is a possibility that workability may be deteriorated such that the material cannot be poured into the mold. More preferably, the lower limit is 350 and the upper limit is 30000.
In addition, as a weight average molecular weight, it can obtain | require on the GPC conditions mentioned above using a gel permeation (GPC) apparatus, for example.

In the radical curable resin, the content ratio of the radical polymerizable oligomer is 30% by mass with respect to 100% by mass of the radical curable resin (total amount of radical polymerizable oligomer and polymerizable monomer), and the upper limit is It is suitable that it is 90 mass%. If it exceeds 90% by mass, the viscosity cannot be sufficiently reduced and the workability may not be excellent. If it is less than 30% by mass, the strength and hot water resistance can be sufficiently improved. It may not be possible. More preferably, the lower limit is 35% by mass and the upper limit is 85% by mass, and more preferably the lower limit is 40% by mass and the upper limit is 80% by mass.

The unsaturated polyester, vinyl ester, polyester (meth) acrylate, urethane (meth) aclute, (meth) acrylate polymer, and polyether (meth) acrylate will be described below.
<Unsaturated polyester>
The unsaturated polyester can be obtained by a condensation reaction of an acid component (polybasic acid component) with a glycol component and / or an epoxy compound component. The reaction molar ratio of the acid component to the glycol component and / or the epoxy compound component is not particularly limited. For example, when the acid component: glycol component and / or epoxy compound component is used, 10: 8 to 10: 12 is preferred. Further, the method for condensing the polybasic acid component and the alcohol component (glycol component and / or epoxy compound component) is not particularly limited, and for example, reaction conditions such as reaction temperature and reaction time may be set as appropriate.

The acid component may be a compound having two or more substituents that can react with a hydroxyl group and / or an epoxy group contained in a glycol component and / or an epoxy compound component to form an ester bond, and is unsaturated. A polybasic acid is essential, and a part thereof may be replaced with a saturated polybasic acid. In this case, the use ratio of the saturated polybasic acid in all the polybasic acid components is preferably 70 mol% or less. If it exceeds 70 mol%, the amount of unsaturated acid used may decrease, and the curability and strength may not be improved. A more preferred lower limit is 40 mol%. Moreover, a more preferable upper limit is 60 mol%, and further preferably 50 mol%.
Examples of the unsaturated polybasic acid include α, β-unsaturated polybasic acids such as maleic acid, fumaric acid, aconitic acid, and itaconic acid; β, γ-unsaturated polybasic acids such as dihydromuconic acid; One or more of acid anhydrides; halides of these acids; alkyl esters of these acids, and the like can be used.

Examples of the saturated polybasic acid include malonic acid, succinic acid, methyl succinic acid, 2,2-dimethyl succinic acid, 2,3-dimethyl succinic acid, hexyl succinic acid, glutaric acid, 2-methyl glutaric acid, 3- Aliphatic saturated polybasic acids such as methyl glutaric acid, 2,2-dimethyl glutaric acid, 3,3-dimethyl glutaric acid, 3,3-diethyl glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid Aromatic aromatic polybasic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid and pyromellitic acid; het acid, 1,2-hexahydrophthalic acid, 1,1-cyclobutanedicarboxylic acid, trans-1, Alicyclic saturated polybasic acids such as 4-cyclohexanedicarboxylic acid and dimer acid; anhydrides of these acids; halides of these acids; It can be of use one or more such alkyl ester.
Among these, it is preferable to use isophthalic acid and / or terephthalic acid when used in applications requiring particularly hot water resistance and strength. In this case, the amount of isophthalic acid and / or terephthalic acid used is preferably 30 mol% or more with respect to 100 mol% of the saturated polybasic acid component.

Examples of the glycol component include ethylene glycol, diethylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, and 2,3-butane. Diol, dipropylene glycol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2-ethyl-1,4-butanediol, 1 , 7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanediol, 1,4-dimethylolcyclohexane, 2,2-diethylpropane-1 , 3-diol, 3-methylpentane-1,4-diol, 2,2-diethylbutane 1,3-diol, 4,5-nonanediol, triethylene glycol, hydrogenated bisphenol A, alkylene oxide adduct of bisphenol A, alkylene oxide adduct of hydrogenated bisphenol A, glycerin, trimethylolpropane, pentaerythritol 1 type, or 2 or more types, such as dipentaerythritol, can be used. Of these, ether glycol is preferably used. More preferred are diethylene glycol (DEG), triethylene glycol (TEG), and tetraethylene glycol (TetraEG).

As the glycol component, when used in applications requiring water resistance such as baths, among the above compounds, neopentyl glycol (NPG), bisphenol A-alkylene oxide adduct and hydrogenated bisphenol A (HBPA). Of these, at least one is preferably used. In this case, the usage amount of neopentyl glycol, bisphenol A-alkylene oxide adduct and hydrogenated bisphenol A is 10 mol% at the lower limit and 100 mol at the upper limit with respect to 100 mol% of the total glycol component and / or epoxy compound component. % Is preferred. If it is less than 10 mol%, the hot water resistance may not be sufficient. If it exceeds 80 mol%, the cured product becomes brittle, and cracks are likely to occur due to external stress or impact. More preferably, the lower limit is 30 mol% and the upper limit is 70 mol%.

Examples of the epoxy compound component include one or two of ethylene oxide, propylene oxide, butylene oxide, styrene oxide, 3,4-epoxy-1-butene, glycidyl acrylate, glycidyl methacrylate, bisphenol A diglycidyl ether, and the like. The above can be used.

The unsaturated polyester may be produced by replacing a part of the raw material with a compound having an unsaturated bond such as an allyl group shown below. In this case, a so-called air-curable polyester may be used. it can. Specifically, at least the whole or a part of the above-described polybasic acid component is replaced with the unsaturated polybasic acid having an unsaturated bond such as an allyl group shown below, or the above-described normal glycol component and / or epoxy. What is necessary is just to replace the whole quantity or one part of a compound component with the glycol component and / or epoxy compound component which have unsaturated bonds, such as the allyl group shown below.

Examples of the unsaturated polybasic acid component having an unsaturated bond include tetrahydrophthalic anhydride, α-terpinene-maleic anhydride adduct, dicyclopentadiene-maleic anhydride adduct (endomethylenetetrahydrophthalic acid), and rosin. 1 type, or 2 or more types, such as ester gum, dry oil fatty acid, semi-dry oil, and fatty acid, can be used.
Examples of the glycol component and / or epoxy compound component having an unsaturated bond include trimethylolpropane monoallyl ether, trimethylolpropane diallyl ether, trimethylolethane monoallyl ether, trimethylolethane diallyl ether, and pentaerythritol monoallyl ether. , Pentaerythritol diallyl ether, pentaerythritol triallyl ether, glycerin monoallyl ether, glyceryl diallyl ether, allyl glycidyl ether, or the like can be used.

Among the above replacement forms, a part of the polybasic acid component is replaced with an unsaturated polybasic acid adduct of dicyclopentadiene, and a part of the glycol component is replaced with a glycol adduct of dicyclopentadiene or hydroxydicyclopentadiene. It is preferable to replace with As an unsaturated polybasic acid adduct, an adduct obtained by adding an unsaturated polybasic acid to dicyclopentadiene, for example, an unsaturated dicarboxylic acid addition of dicyclopentadiene such as a maleic acid adduct of dicyclopentadiene Can be used. The maleic acid adduct of dicyclopentadiene can be produced by adding dicyclopentadiene and maleic anhydride in the presence of water.
By such replacement, it is possible to obtain an unsaturated polyester having a dicyclopentadiene skeleton, thereby realizing a low viscosity of the resin and reducing the use ratio of the polymerizable monomer, It is possible to sufficiently suppress the volatilization of the polymerizable monomer, and it is possible to suppress odor during handling.
The dicyclopentadiene (norbornene) skeleton is a skeleton represented by the following general formula (2) or (3).

The unsaturated polyester having a dicyclopentadiene skeleton also includes addition of an acid component or a glycol component and / or an epoxy compound component with dicyclopentadiene during condensation polymerization of the acid component with a glycol component and / or an epoxy compound component. Can also be obtained by generating a compound having a dicyclopentadiene skeleton. That is, an acid component and a glycol component and / or an epoxy compound component used in ordinary unsaturated polyester may be mixed with dicyclopentadiene to perform condensation polymerization, and the acid component, glycol component and / or Dicyclopentadiene may be added after mixing the epoxy compound component and initiating condensation polymerization.

<Vinyl ester>
The vinyl ester is preferably obtained by a reaction between an epoxy resin and an unsaturated monobasic acid.
As the unsaturated monobasic acid, acrylic acid, methacrylic acid and the like are preferable.
As the epoxy resin, for example, bisphenol A resin, novolac resin, resol resin, bisphenol F resin, hydrogenated bisphenol A aliphatic epoxy resin, and the like are suitable. The bisphenol A resin or bisphenol F resin is preferably a reaction product obtained by reacting bisphenol A and / or bisphenol F with an aliphatic diglycidyl ether type epoxy compound.

The aliphatic diglycidyl ether type epoxy compound is a diglycidyl ether type epoxy compound of an aliphatic bifunctional alcohol, and preferably has an epoxy equivalent of 300 or less, such as 1,6-hexanediol diglycidyl ether. Neopentyl glycol diglycidyl ether, (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, (di) glycerol (poly) glycidyl ether, polytetramethylene glycol diglycidyl ether and the like are suitable.
The kind and amount of the epoxy resin and unsaturated monobasic acid in the vinyl ester are not particularly limited, and may be set as appropriate according to the intended use. Moreover, it does not specifically limit as a method to make these react, What is necessary is just to set reaction conditions, such as reaction temperature and reaction time, suitably.

<Polyester (meth) acrylate>
The polyester (meth) acrylate is preferably obtained by an esterification reaction with (meth) acrylic acids, a polyhydric alcohol, and a polybasic acid.
Examples of the (meth) acrylic acids include (meth) acrylic acid and derivatives thereof capable of forming an ester bond with a hydroxyl group such as (meth) acrylic acid, (meth) acrylic acid alkyl ester, and (meth) acrylic acid halide. Preferably there is.

Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5 -Pentanediol, 1,6-hexanediol, neopentyl glycol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 2-methylpropane-1 , 3-diol, trimethylolpropane, hydrogenated bisphenol A, alkylene oxide (for example, ethylene oxide, propylene oxide, etc.) adduct of bisphenol A and the like are suitable.

Examples of the polybasic acid include unsaturated polybasic acids and saturated polybasic acids. Examples of the unsaturated polybasic acid include α, β-unsaturated compounds such as maleic acid, fumaric acid, aconitic acid, and itaconic acid. Polybasic acids; β, γ-unsaturated polybasic acids such as dihydromuconic acid; anhydrides of these acids; halides of these acids; use of one or more of these esters such as alkyl esters Can do. Examples of saturated polybasic acids include malonic acid, succinic acid, methyl succinic acid, 2,2-dimethyl succinic acid, 2,3-dimethyl succinic acid, hexyl succinic acid, glutaric acid, 2-methyl glutaric acid, 3 -Aliphatic saturated polybases such as methyl glutaric acid, 2,2-dimethyl glutaric acid, 3,3-dimethyl glutaric acid, 3,3-diethyl glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid Acid: aromatic saturated polybasic acid such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid; het acid, 1,2-hexahydrophthalic acid, 1,1-cyclobutanedicarboxylic acid, trans-1 Cycloaliphatic saturated polybasic acids such as 1,4-cyclohexanedicarboxylic acid and dimer acid; anhydrides of these acids; halides of these acids; It can be used one or two or more of such alkyl esters of the acids.
The type and amount of (meth) acrylic acid, polyhydric alcohol, and polybasic acid in the polyester (meth) acrylate are not particularly limited, and may be appropriately set depending on the intended use. Moreover, it does not specifically limit as a method to make these react, What is necessary is just to set reaction conditions, such as reaction temperature and reaction time, suitably.

<Urethane (meth) acrylate>
The urethane (meth) acrylate is preferably obtained by urethanizing a polyisocyanate, a (meth) acrylate having a hydroxyl group, and, if necessary, a polyol.
Examples of the polyisocyanate include 2,4-tolylene diisocyanate and its isomer, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, dicyclohexylmethane diisocyanate, tolidine diisocyanate, naphthalene diisocyanate, One or more types such as triphenylmethane triisocyanate are suitable.

Examples of the (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and polypropylene glycol. One or two of mono (meth) acrylates such as mono (meth) acrylate and polyvalent (meth) acrylates such as tris (hydroxyethyl) isocyanuric acid di (meth) acrylate and pentaerythritol tri (meth) acrylate More than species are preferred.

As said polyol, 1 type (s) or 2 or more types, such as a polyether polyol, a polyester polyol, a polycarbonate polyol, a polybutadiene polyol, are suitable, for example, and the number average molecular weight is 200-3000. More preferably, the number average molecular weight is 400 to 2000. The polyether polyol may be a polyol obtained by adding an alkylene oxide to bisphenol A or bisphenol F in addition to a polyalkylene oxide such as polyethylene glycol, polypropylene glycol, or polytetramethylene glycol. The polyester polyol is a condensation polymer of a dibasic acid component and a polyhydric alcohol component, or a ring-opening polymer of a cyclic ester compound such as polycaprolactone.

The type and amount of the polyisocyanate in the urethane (meth) acrylate, the hydroxyl group-containing (meth) acrylate and the polyol, the reaction method and the like are not particularly limited, and may be appropriately set according to the use application. It is preferable to adjust the amount of use so that the equivalent ratio of the hydroxyl group to the isocyanate group is approximately 1, and to heat in the range of 40 to 140 ° C. In order to further accelerate the urethanization reaction, a commonly used urethanization catalyst can be used, and it is preferable to use tin compounds such as tertiary amines, dibutyltin dilaurate, and tin chloride.

<(Meth) acrylate polymer>
Examples of the (meth) acrylate-based polymer include polymers such as methyl methacrylate. Moreover, in order to introduce an acid or epoxy functional group into the polymer, a copolymer obtained by copolymerizing acrylic acid or glycidyl methacrylic acid, or a polymer having a polymerizable functional group by reacting with the functional group It is also possible to use those obtained by copolymerizing monomers such as styrene other than acrylic.
In the case of obtaining a radical curable resin containing the (meth) acrylate polymer and the polymerizable monomer, a polymerizable monomer such as a (meth) acrylic acid ester monomer such as methyl methacrylate. A resin (acrylic syrup) dissolved in the body is preferred. As the polymerizable monomer in this case, a polyfunctional vinyl monomer such as ethylene glycol methacrylate or trimethylolpropane trimethacrylate may be used in order to increase heat resistance.

<Polyether (meth) acrylate>
The polyether (meth) acrylate is preferably a product (esterified product) obtained by an esterification reaction of a divalent or higher alcohol with (meth) acrylic acid.
Examples of the esterified product of a dihydric or higher alcohol and (meth) acrylic acid include diethylene glycol, polyethylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, and 1,4-butanediol. , Polypropylene glycol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanediol, 1,4-dimethylolcyclohexane, hydroxypivalylhydroxy Divalent alcohols such as pivalate, triethylene glycol, tetraethylene glycol, bisphenol F, bisphenol Z, bisphenol S, bisphenol AF, bisphenol C, bisphenol FD, hydrogenated bisphenol A, bisphenol A and the like Diesters obtained by reaction of one or more of these alkylene oxide adducts and the like with (meth) acrylic acid; glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, novolak phenol, cresol novolak, etc. Diesters and triesters obtained by reacting one or more of trivalent or higher alcohols and adducts of these alkylene oxides with (meth) acrylic acid are preferred.
In addition, as alcohol used, it is especially preferable that it is the alcohol which has a benzene ring, and / or its alkylene oxide adduct among the above-mentioned.

As a preferable form of the esterified product of the above-mentioned dihydric or higher alcohol and (meth) acrylic acid, a form having 2 to 4 terminal groups having a (meth) acryloyl group at the terminal of the oxyalkylene chain is preferable. is there.
In such a form, the number of oxyalkylene units contained in one oxyalkylene chain is preferably 1 at the lower limit and 10 at the upper limit. If the number of oxyalkylene units is 0, that is, there is no oxyalkylene chain, the film formed using the radical curable resin composition of the present invention may not have sufficient flexibility and substrate followability. If it exceeds 10, the cured product may not be excellent in water resistance. A more preferred lower limit is two. Further, the upper limit is more preferably 8, and still more preferably 4.

The oxyalkylene unit is preferably composed of an oxyalkylene unit having 2 to 4 carbon atoms. That is, the oxyalkylene unit is preferably composed of at least one oxyalkylene unit selected from the group consisting of oxyethylene units, oxypropylene units and oxybutylene units. When the number of carbon atoms in the oxyalkylene unit exceeds 4, the viscosity of the radical curable resin composition increases, and there is a possibility that the work cannot be performed more efficiently. More preferably, it is constituted by oxyalkylene units having 2 to 3 carbon atoms, and more preferably, it is constituted by oxyalkylene units having 2 carbon atoms, that is, oxyethylene units. In addition, when it has two or more oxyalkylene units, they may all be the same or different. In addition, the two or more oxyalkylene chains in the molecule may have the same or different oxyalkylene unit structure.

The esterified product of the divalent or higher alcohol and (meth) acrylic acid is also preferably in a form having a phenol residue. A phenol residue means a residue having a structure in which active hydrogen is removed from a hydroxyl group of phenol, and one such residue may be contained in one molecule or two or more. May be.
A preferred form of such an esterified product is a form having a structure derived from bisphenol A. Among them, an esterified product of an alkylene oxide adduct of bisphenol A and (meth) acrylic acid is preferable. . More preferably, the following general formula (4);

(In the formula, R ⁶ is the same or different and represents a hydrogen atom or a methyl group. R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are the same or different and represent a hydrogen atom or a methyl group. N and m Are the same or different and represent an integer of 0 to 10 and n + m is 1 or more and 10 or less.) Di (meth) acrylate of an alkylene oxide adduct of bisphenol A having a structure represented by is there.

In the radical curable resin, examples of the polymerizable monomer include styrene, vinyltoluene, paramethylstyrene, chlorostyrene, divinylbenzene, vinyl acetate; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meta ) Monofunctional alkyl (meth) acrylates such as acrylate and hexyl (meth) acrylate; cyclic in the molecule such as cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, benzyl methacrylate, isobornyl methacrylate, dicyclopentenyloxyethyl methacrylate, and phenoxyethyl methacrylate Monofunctional (meth) acrylate having structure: (poly) ethylene glycol di (meth) acrylate, neopentyl glycol dimethacrylate, (poly) propylene Can be used Rikoruji (meth) acrylate, bisphenol A alkylene oxide di (meth) acrylate, one or more such polyfunctional (meth) acrylates such as trimethylolpropane tri (meth) acrylate. Among these, in consideration of various physical properties such as economy and water resistance, it is preferable to use styrene, and more preferably 30 to 100% by mass with respect to 100% by mass of the total amount of polymerizable monomers. .
The polymerizable monomer preferably has a viscosity at 25 ° C. of 100 mPa · s or less. Thereby, the viscosity of the resin composition can be sufficiently reduced, and the workability can be sufficiently improved.

As a content ratio of the polymerizable monomer, the lower limit is 10% by mass and the upper limit is 90% by mass with respect to 100% by mass of the radical curable resin (total of radical polymerizable oligomer and polymerizable monomer). Is preferred. If it exceeds 90% by mass, the resulting resin will not have sufficient chemical resistance, toughness, and curability, and the odor may not be good. Further, the amount of the remaining polymerizable monomer is increased, and this may cause an increase in the amount of emission from the molded body. On the other hand, if it is less than 10% by mass, the surface properties such as the surface hardness of the cured product will not be excellent, and the viscosity cannot be sufficiently reduced and the workability will not be excellent. There is a fear. More preferably, the lower limit is 15% by mass and the upper limit is 80% by mass. More preferably, the lower limit is 20% by mass and the upper limit is 70% by mass.

As the above-mentioned radical curable resin, unsaturated polyester resin, vinyl ester resin, polyester (meth) acrylate, urethane (meth) aclute, acrylic syrup obtained by dissolving the above-mentioned radical polymerizable oligomer in a polymerizable monomer And polyether (meth) acrylates are preferred. As described above, the radical curable resin is at least one selected from the group consisting of unsaturated polyester resins, vinyl ester resins, polyester (meth) acrylates, urethane (meth) aclutes, acrylic syrups, and polyether (meth) acrylates. The form which is a resin is also a preferred form of the present invention. The unsaturated polyester resin is more preferable because it is excellent in various physical properties such as toughness, strength, durability, hot water resistance, transparency, economy, and curability.

As the radical curable resin composition, a polymerization inhibitor, an inert powder, a thixotropic agent (a thixotropic agent), a filler, as necessary, within a range not impairing the effects of the present invention. BYK-354 (drying improver, thickener, colorant, fiber reinforcing material, curing agent, curing accelerator, wax, BYK-R605 (trade name, manufactured by BYK Chemie), and the like. 1 type of leveling agent (trade name, manufactured by Big Chemie), defoaming agents such as BYK-A515, A525, A555 (trade name, manufactured by Big Chemie), aggregates, etc. Or you may contain 2 or more types. The amount of these used is preferably set as appropriate according to the use of the radical curable resin composition.

Examples of the polymerization inhibitor (stabilizer) include hydroquinones such as hydroquinone, methylhydroquinone, 2-methylhydroquinone, t-butylhydroquinone and mono-t-butylhydroquinone; benzoquinones such as benzoquinone and methyl-p-benzoquinone. Catechols such as catechol and t-butylcatechol; phenols such as 2,6-di-t-butyl-4-methylphenol, 4-methoxyphenol and cresol; phenothiazine, ferdazil, α, α-diphenyl-β- Examples include picryl hydrazyl (DPPH), 4-hydroxy 2,2,6,6-tetramethylpiperidine-1-oxyl.
Examples of the inert powder include thermoplastic resins such as polyethylene, polypropylene, and polystyrene, thermosetting resin cured products such as acrylic resin, polyester resin, phenol resin, and urethane resin, powders such as rubber and wood, and / or Or a pulverized material etc. are mentioned.
Examples of the thixotropic agent (thixotropic agent) include anhydrous fine powder silica, asbestos, clay and the like.

Examples of the filler include aluminum hydroxide (ATH), calcium carbonate, calcium sulfate, barium sulfate, alumina, clay, talc, glass powder, milled fiber, cristobalite, mica, silica, river sand, diatomaceous earth, mica powder, gypsum. And inorganic fillers such as glass powder; organic fillers and the like.
Examples of the drying improver include unsaturated or saturated polyester oligomers having an allyloxy group such as drying oil, allyl glycidyl ether, diethylene glycol and maleic anhydride addition polymers.
Examples of the thickener include metal oxides such as magnesium oxide, calcium oxide, and zinc oxide; isocyanates; oxazolines and the like.
Examples of the colorant include organic pigments, inorganic pigments, dyes, and the like.
Examples of the fiber reinforcement include inorganic fibers such as glass fiber and carbon fiber; organic fibers such as aramid fiber, polyester fiber, and nylon fiber. The shape of the fiber reinforcement includes a mat shape, a chop shape, Examples include a roving shape.

As said hardening | curing agent, what is used normally can be used, for example, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, 1,1,3, Hydroperoxides such as 3-tetramethylbutyl hydroperoxide; Ketone peroxides such as methyl ethyl ketone peroxide and acetylacetone peroxide; Diacyl peroxides such as benzoyl peroxide; Dialkyls such as dicumyl peroxide and t-butylcumyl peroxide Peroxide; 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxybenzoate, etc. Alkyl peroxides; peroxides such as bis (4-tert-butylcyclohexyl) peroxydicarbonate; such as 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile 1 type (s) or 2 or more types, such as an azo compound, can be used.

The curing agent may be in a form containing a solvent. As a solvent, 1 type (s) or 2 or more types, such as organic solvents, such as dioctyl phthalate, dimethyl phthalate, benzene, xylene, toluene, water, etc. can be used, for example. The content of these solvents is not particularly limited, but for example, it is preferably 90% by mass or less with respect to 100% by mass of the curing agent.
As a usage-amount of the said hardening | curing agent, when it is previously contained in the radical curable resin composition, as a content, a minimum is 0.1 mass% with respect to 100 mass% of radical curable resin compositions, and an upper limit is It is suitable that it is 5 mass%. Moreover, when adding and mixing to the radical curable resin composition immediately before molding, the lower limit is preferably 0.1% by mass and the upper limit is preferably 10% by mass with respect to 100% by mass of the radical curable resin composition. More preferably, the lower limit is 0.5 mass% and the upper limit is 5 mass%.

Examples of the curing accelerator include metal soaps such as cobalt naphthenate, manganese naphthenate, copper naphthenate, potassium naphthenate, calcium naphthenate, cobalt octylate, manganese octylate; cobalt acetylacetonate, vanadium acetylacetate Metal chelate compounds such as narate; amine compounds such as dimethylaniline, N, N′-dimethylaniline, N, N-dimethyltoluidine, N, N-diethylaniline, N, N-di (hydroxy) -4-methylaniline; Β-diketones, β-ketoesters, β-ketoamides and the like other than the acetyllactone compounds and acetoacetamide compounds such as acetylacetone and ethyl acetoacetate can be used, and one or more of these can be used. Among these, it is preferable to use a metal soap, and it is more preferable to use a cobalt salt.
Although it does not specifically limit as the usage-amount of the said hardening accelerator, For example, it is suitable that a minimum is 0.1 mass part and an upper limit is 10 mass parts with respect to 100 mass parts of radical curable resin. More preferably, the lower limit is 0.2 parts by mass and the upper limit is 7 parts by mass.

It does not specifically limit as a method of manufacturing the radical curable resin composition of this invention, For example, by mixing the oxazoline group containing polymer and the other component added as needed to the said radical curable resin. It can be carried out.
The oxazoline group-containing polymer may be used as it is, but can also be used after being dissolved in a solvent or diluent. Examples of the solvent and diluent include monomers having a polymerizable unsaturated group such as styrene, vinyltoluene, methyl methacrylate, and vinyl acetate in addition to toluene, xylene, butyl acetate, and the like. Among these, it is preferable to use styrene. When used by dissolving in a solvent or diluent, the mixing ratio of the oxazoline group-containing polymer to the solvent or diluent (oxazoline group-containing polymer / solvent or diluent) is, for example, 10 to 60/90 to 40 It is preferable that More preferably, it is 15-50 / 85-50.

The radical curable resin composition of the present invention can sufficiently suppress shrinkage during curing without separation even after a long period of time, while eliminating defects such as cracking and warping during molding. A molded product having a high appearance can be obtained, and can be preferably used for various applications. For example, FRP products such as hulls, septic tanks, bathtubs, vehicles, water tanks, electrical parts, resin concrete, gel coats, paints, putty, decorative boards, adhesives, casting materials; concrete, asphalt, mortar, steel plates, glass, It is suitably used for a covering material such as a thermoplastic plastic; a covering material for civil engineering and construction such as a lining material and a coated flooring material. Among them, since the effects of the present invention are sufficiently exhibited, molding of FRP products such as bathtubs, septic tanks, vehicle members, electrical parts, pipes, cast molded products, resin concrete, etc., which requires a high appearance is required. It is particularly suitable for use as a raw material for products.

Although it does not specifically limit as a shaping | molding method suitable for use of the said radical curable resin composition, For example, medium temperature shaping | molding methods, such as casting and centrifugal molding in which a low shrinkage agent is often used, SMC (Sheet Molding Compounds Method) The high blend compression molding method represented by the BMC method, BMC (Bulk Molding Compound Method) method, etc. are suitable. Thus, if the radical curable resin composition is in the form of a heat compression molding material represented by SMC and BMC, the radical curable resin composition generally contains a curing agent.

When producing a molding material using the radical curable resin composition of the present invention, a curing agent, a low shrinkage agent, a filler, an additive, an increase in the radical curable resin such as the unsaturated polyester resin described above. It is preferable to manufacture by mixing a sticking agent and the like and impregnating it with a fibrous reinforcing material such as glass fiber, or kneading with a fibrous reinforcing material.
Although content of the said radical curable resin composition in a molding material is not specifically limited, When a molding material is 100 mass parts, Preferably it is 10-90 mass parts, Most preferably, it is 10-80 mass parts.

As the low shrinkage agent used in the present invention, the above-mentioned oxazoline group-containing polymer is suitable. Furthermore, you may use together what is generally used with respect to resin, such as unsaturated polyester resin. Specifically, for example, polyethylene, polypropylene, polystyrene, crosslinked polystyrene, polyvinyl acetate, cellulose acetate, polyacrylic acid ester, polybutadiene, polyvinyl ether; hydrogenated polybutadiene as an elastomer, styrene-ethylene-butadiene copolymer Examples include polymers and various butadiene rubbers; polycaprolactone, saturated polyesters, and the like. From the viewpoint of workability, as the low shrinkage agent, the oxazoline group-containing polymer is particularly preferably used as a polystyrene solution using a styrene monomer as a medium.

Examples of the thickener used in the present invention include alkaline earth metal oxides such as magnesium oxide, calcium oxide and calcium hydroxide; alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide. There is no particular limitation. These thickeners may be used alone or in combination of two or more. The amount of the thickener used is preferably in the range of 5 parts by mass or less with respect to 100 parts by mass of the radical curable resin such as unsaturated polyester resin.

The curing agent, filler, and additive may be selected from those described above. The final blending of the molding material is used as necessary for characteristics such as various physical properties required for the molding material to be manufactured, for example, improvement of workability and improvement of quality performance.

Development as a photocurable resin composition can also be expected by using a photopolymerizable initiator in addition to the above-described initiator as an initiator for the radical curable resin of the present invention. Applications include paints, adhesives, pressure-sensitive adhesives, overcoat agents, printing inks, photosensitive resins for printing plates, and the like. In particular, the addition of an oxazoline group-containing polymer can be expected to improve the dispersibility of pigments, inks, and the like, and the adhesiveness to the substrate can be expected by curing the oxazoline group.

The radical curable resin composition of the present invention is configured as described above, and can sufficiently suppress shrinkage during curing without separation even after a long period of time, and cracks and warpage during molding. Since it is possible to give a cured product (molded product) exhibiting a high appearance while eliminating such problems as, etc., it is useful for various applications, in particular, a bathtub that requires a high appearance, It is particularly suitable as a raw material for FRP products such as septic tanks, vehicle members, electrical parts, pipes, cast molded products, and resin molded concrete products.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by mass”.

Production Example 1
(Production of low shrinkage agent A)
A reaction vessel equipped with a reflux tube, a temperature sensor, a gas introduction tube, a dropping device, and a stirring device was sufficiently replaced with nitrogen gas. Next, 100 parts of toluene as a solvent was charged into the reaction vessel. On the other hand, 90 parts by mass of styrene and a mixture of 10 parts of 2-isopropenyl-2-oxazoline, which is a polymerizable monomer (monomer) having an oxazoline group, and t-butylperoxy- 2 parts of 2-ethylhexanoate was charged. Next, after heating up said reaction solution to 100 degreeC, the said monomer mixture and polymerization initiator in a dripping apparatus were dripped gradually to this reaction solution over 4 hours under stirring. After completion of the dropwise addition, the reaction solution was further stirred for 3 hours to complete the reaction. As a result, a colorless transparent viscous polymer (polymer) solution was obtained. Next, this polymer solution was subjected to a vent type screw twin screw extruder (φ = 29.4) having a barrel temperature of 220 ° C., a rotation speed of 100 rpm, a degree of vacuum of 15 to 400 hPa (10 to 300 mmHg), a rear vent number of 1, and a forevent number of 4. 75 mm, L / D = 30) at a processing rate of 2.0 kg / hour in terms of resin amount to obtain an oxazoline group-containing polymer (polymer A). It was 150,000 when the weight average molecular weight (Mw) of the polymer A was measured by the method (GPC measurement, polystyrene conversion) mentioned above.
30 parts of the copolymer thus obtained and 70 parts of styrene were mixed and dissolved to obtain a low shrinkage agent A.

Production Example 2
(Production of low shrinkage agent B)
70 parts of commercially available polystyrene (weight average molecular weight 200000) and 30 parts of styrene were mixed and dissolved to obtain a low shrinkage agent B.

Examples 1-2, Comparative Example 1
(Confirmation of separation prevention effect)
Each raw material was added with the composition shown in Table 1, and after stirring for 5 minutes with a three-one motor, the separated state of the mixed solution was visually observed over time (after standing at 23 ° C., 8 hours, 24 hours, and 48 hours) After), it was evaluated as follows. The results are shown in Table 1.
◯: Not separated △: Slightly separated ×: Separated

Examples 3-4, Comparative Example 2
(Volume shrinkage)
A resin mixture was prepared with the formulation shown in Table 2, and the liquid specific gravity at 25 ° C. was measured. Furthermore, 10 g of this mixture was put into a test tube and heated in a 100 ° C. oil bath. After 3 hours, the test tube was taken out, and the cured product specific gravity at 25 ° C. of the cured product in the test tube was measured. The volumetric shrinkage was calculated from these two specific gravity values. The results are shown in Table 2.

In Tables 1 and 2, Polyhope 6409 (trade name) is an unsaturated polyester resin made by Japan Composite, and perbutyl Z (trade name) is t-butyl peroxybenzoate made by NOF Corporation. .
Moreover, in the said Tables 1-2, the low shrinkage agent and perbutyl Z were shown as the quantity (part) with respect to 100 parts of polypop 6409. In addition, about the comparative example 2 of Table 2, perbutyl Z was shown as a quantity (part) with respect to 120 parts of poly pops 6409.

Example 5
80 parts of unsaturated polyester resin (trade name “Polyhope 6409”, manufactured by Japan Composite), 2 parts of low shrinkage agent A, 18 parts of low shrinkage agent B, calcium carbonate as a filler (trade name “NS -100 ", manufactured by Nitto Flour Chemical Co., Ltd.), 150 parts, Perbutyl Z as a curing agent (trade name, manufactured by NOF Corporation), 5 parts of zinc stearate as a release agent, magnesium oxide as a thickener (Kyowa) A compound was obtained by mixing 1 part).
Next, after applying the compound to the polyethylene film surface so as to have a certain thickness, a glass fiber (a chopped strand having a length of 1 inch: manufactured by Nitto Boseki Co., Ltd.) as a reinforcing material is uniformly applied on the coated material. I distributed it. And the coating material formed by apply | coating a compound so that it might become fixed thickness on the polyethylene film surface on this was piled up. In other words, glass fiber was sandwiched between the compounds. Thereby, SMC as a molding material for pressure molding was obtained. The ratio of the glass fiber in the SMC was adjusted to 25% by mass. Thereafter, the obtained SMC was packaged with a cellophane film and aged at 40 ° C. for 48 hours. Next, the above SMC was compression molded. That is, a mold having a predetermined size was used, the temperature of the upper mold was set to 145 ° C, and the temperature of the lower mold was set to 130 ° C. Then, SMC cut into a predetermined size was filled in the above mold, clamped at a pressure of 7 MPa, and compression molded for 5 minutes, thereby molding a miniature bath as a molded product.
Next, the surface of the molded product was visually observed. The surface was not glossy, and a good molded product was obtained.

Comparative Example 3
An SMC was obtained in the same manner as in Example 5 except that the low shrinkage agent B was used alone as the low shrinkage agent. Thereafter, a miniature bath was formed, and the appearance was visually observed. The surface was glossy and was worse than Example 5.

Claims (5)

A radical curable resin composition comprising an oxazoline group-containing polymer and a radical curable resin. The radical curable resin according to claim 1, wherein the oxazoline group-containing polymer is obtained by polymerizing an addition polymerizable oxazoline and an addition polymerizable monomer component that does not react with the oxazoline group. Composition. The radically curable resin composition according to claim 2, wherein the addition-polymerizable oxazoline is 1 to 50% by mass with respect to 100% by mass of all monomer components. The radically curable resin composition according to claim 2 or 3, wherein the addition polymerizable monomer component that does not react with the oxazoline group is styrene. The radical curable resin is at least one resin selected from the group consisting of unsaturated polyester resins, vinyl ester resins, polyester (meth) acrylates, urethane (meth) aclutes, acrylic syrups and polyether (meth) acrylates. The radical curable resin composition according to claim 1, wherein the composition is a radical curable resin composition.