JPS62273248A - Thermosetting resin composition having low shrinkage - Google Patents

Abstract

PURPOSE:To obtain the titled composition having excellent storage stability and giving a cured product having low cure-shrinkage and excellent surface smoothness and luster without staining the mold nor causing mottling of the product, by compounding a specific hydroxyl-containing (meth)acrylate polymer with a thermosetting resin. CONSTITUTION:The objective composition can be produced by compounding (A) a hydroxyl-containing (meth)acrylate polymer produced by polymerizing a hydroxyl-containing (meth)acrylate oligomer of formula (R is H or methyl; Z is 2-20C bivalent organic group; n is 1-100) and optionally a monomer copolymerizable with said oligomer and (B) a thermosetting resin. The content of the oligomer in the component A is 5-90(wt)% and the amount of the component A is 1-40%, preferably 2-30% of the sum of the components A and B.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermosetting resin composition that exhibits small volume shrinkage upon curing.

(Prior Art) Thermosetting resins such as unsaturated polyester resins have problems such as significant shrinkage during molding and curing, resulting in cracks and surface waviness, which impairs surface smoothness. All of these problems are caused by volumetric shrinkage during resin curing.

Conventionally, as a method to solve such problems, thermoplastic resins such as polystyrene, polymethyl methacrylate, polyvinyl acetate, saturated polyester, ethylene-vinyl acetate copolymer, polyurethane, etc., have been combined with monomers that can be copolymerized with thermosetting resins. A method was proposed to reduce the shrinkage rate by dissolving or dispersing it in a thermosetting resin and precipitating the thermoplastic resin when the thermosetting resin hardens. ing.

(Problems to be Solved by the Invention) However, these conventional methods have problems with the storage stability of the resulting resin composition, causing uneven coloring and mold staining, and
Moreover, the low shrinkage effect may also be insufficient in some cases.

These disadvantages include poor dispersibility of the thermoplastic resin in the resin composition, the thermoplastic resin may separate and float on the surface, or the dissolved thermoplastic resin may not precipitate uniformly. This occurs due to the following causes.

As mentioned above, although the conventional method for reducing shrinkage achieves a certain degree of reduction in shrinkage, there remain problems in mold staining and color unevenness that accompany the reduction in shrinkage.

The present invention was made in view of the above points, and its purpose is to provide a cured molded product with excellent storage stability, low shrinkage during curing, and good surface smoothness and gloss, while preventing mold stains. An object of the present invention is to provide a low-shrinkage thermosetting resin composition that does not cause color unevenness.

(Means and effects for solving the problems) The present invention has the following features:
General formula % Formula % (However, in the formula, R is a hydrogen atom or a methyl group, which may be the same or stationery, and Z is a divalent organic group having 2 to 20 carbon atoms, and each is the same.) or stationery, and n is an integer from 1 to 100.

) A hydroxyl group-containing (meth)acrylate polymer (1) obtained by polymerizing a hydroxyl group-containing (meth)acrylate oligomer represented by (1) and, if necessary, a monomer copolymerizable with the oligomer; The present invention relates to a low-shrinkage thermosetting resin composition characterized by comprising a thermosetting resin (Ill).

The hydroxyl group-containing (meth)acrylate polymer (1) constituting the low-shrinkage thermosetting resin composition of the present invention may be a hydroxyl group-containing (meth)acrylate oligomer alone or the oligomer It is obtained by copolymerizing CBI with a monomer copolymerizable with CBI.

The hydroxyl group-containing (meth)acrylate oligomer used in the present invention has the general formula % (wherein, R is a hydrogen atom or a methyl group, and 2 is a divalent organic group having 2 to 20 carbon atoms). It is obtained by addition polymerizing and oligomerizing hydroxy (meth)acrylate (a) represented by: Specific examples of hydroxy(meth)acrylate (a) include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxyethyl acrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, hydroxyhexyl acrylate, hydroxyhexyl methacrylate,
Examples include diethylene glycol monoacrylate, diethylene glycol monomethacrylate, diethylene glycol monoacrylate, dipropylene glycol monomethacrylate, hydroxycyclohexyl acrylate, hydroxyclobexyl methacrylate, and the like.

These may be used alone or as a mixture. For oligomerization by addition polymerization of hydroxy (meth)acrylate (a), for example, Japanese Patent Application No. 59-256
As described in No. 558, hydroxy (meth)acrylate (a) is mixed with a protonic acid such as sulfuric acid or para-toluenesulfonic acid; a Lewis acid such as boron trifluoride or tin tetrachloride; an oxysulfate such as titanium oxysulfate; 10-150'C in the presence of a catalyst such as a heteropolyacid such as storic acid, tungstosilicic acid, molybdophosphoric acid, molybdosilicic acid, etc.
It should be maintained at a temperature of

The monomer (F) that can be copolymerized with the hydroxyl group-containing (meth)acrylate oligomer is not particularly limited, and includes, for example, acrylic esters such as ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate;
Methacrylic acid esters such as methyl methacrylate, butyl methacrylate, and cyclohexyl methacrylate; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid, or half esters of maleic acid, fumaric acid, and itaconic acid. Compounds: Aromatic vinyls such as styrene and vinyltoluene; Unsaturated nitrites such as acrylonitrile and methacrylonitrile: Vinyl acetate,
Vinyl esters such as vinyl propionate can be used, and divinylbenzene, diallyl phthalate, ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, triallyl isocyanurate), N,N'-methylenebis(meth)
A crosslinkable monomer having two or more polymerizable double bonds in one molecule, such as acrylamide, can also be used.

The hydroxyl group-containing (meth)acrylate oligomer is an effective component for improving the affinity of the hydroxyl group-containing (meth)acrylate polymer (1) obtained by polymerization to the thermosetting resin (II). , the polymer (++
It is preferable to use it in an amount of 5 to 90% by weight based on the total monomers constituting it. When the amount of the hydroxyl group-containing (meth)acrylate oligomer (8) is less than 5% by weight,
Molded products obtained by curing the resin composition tend to have reduced gloss, color unevenness, and mold stains during molding. Furthermore, if the amount exceeds 90 wt.i-%, a sufficient low shrinkage effect may not be obtained.

The hydroxyl group-containing (meth)acrylate polymer (1) used in the present invention can be produced by conventionally known tank polymerization methods, but from the viewpoint of ease of reaction control, conventional emulsion polymerization or suspension polymerization using water as a medium is preferred. Preferably, it is prepared by polymerization methods.

Emulsifiers used in emulsion polymerization include anionic surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate, nonionic surfactants such as polyoxyethylene nonylphenol ether and polyoxyethylene lauryl ether, and fats. Raw soap, rosin soap, etc. can be used alone or in combination.

As stabilizers during suspension polymerization, commonly used partially saponified polyvinyl alcohol (PVA), completely saponified P
Water-soluble polymers such as VA, carboxyl group-modified PVA1 gelatin, starch, carboxymethylcellulose, polyacrylates, poorly soluble inorganic fine powders, anionic surfactants, nonionic surfactants, etc., singly or in combination. It can be used as

Examples of the polymerization initiator include inorganic persulfates such as potassium persulfate and ammonium persulfate, organic peroxides such as cumene hydroperoxide, t-butyl hydroperoxide, benzoyl peroxide, and azobisisobutyronitrile. It is possible to use a general polymerization initiator such as, or a so-called redox catalyst in combination with a reducing agent. Furthermore, a molecular weight regulator such as alkyl mercaptan may be added if necessary.

The hydroxyl group-containing (meth)acrylate polymer (1) obtained by the above method is preferably obtained as a dry powder in order to be blended into the thermosetting resin (If). To separate and dry the polymer (1), any known method may be used,
For example, there are various separation methods such as direct drying using a spray dryer or drum dryer, methods of coagulating through processes such as salting out, evaporation, or freezing, followed by washing, filtering, and drying, and separation using natural sedimentation or centrifugal sedimentation. Various drying methods such as natural drying, vacuum drying, and hot air drying can be freely combined and used. In addition, if the resulting polymer (1) powder has strong secondary aggregation, it is preferable to use a crushing device such as a ball mill, hammer mill, or jet mill to loosen the agglomeration before use.

The hydroxyl group-containing (meth)acrylate polymer (1) thus obtained has excellent affinity for the thermosetting resin (It).

The thermosetting resin (I[+) used in the present invention is a radical polymerizable resin consisting of a compound having a polymerizable unsaturated group in the molecule and having a molecular weight of 200 or more and a polymerizable monomer, such as An unsaturated polyester obtained by condensing an unsaturated dibasic acid or its mixture with a saturated dibasic acid and a polyhydric alcohol at elevated temperatures in an inert gas stream and a polymerizable monomer represented by styrene. unsaturated polyester resin and polyfunctional epoxy compound (meth)
Vinyl ester resins consisting of epoxy (meth)acrylate reacted with acrylic acid and polymerizable monomers such as styrene and methyl methacrylate, and furthermore, polyester (meth)acrylates or polyurethane (meth)acrylates and polymerizable monomers. Examples include resin made of a body.

The low-shrinkage thermosetting resin composition of the present invention is formed by blending a thermosetting resin (II) with a hydroxyl group-containing (meth)acrylate polymer (1), and a low-shrinkage agent is used. It can be easily blended by a conventional blending method. For example, a dry powder polymer (11) is directly added to the thermosetting resin (If) and thoroughly stirred, or the polymer (1) is preliminarily mixed with a monomer that can be polymerized with the thermosetting resin (111), e.g. It can be blended by dispersing or dissolving it in styrene or the like and then adding and mixing it to a thermosetting resin (Ill).

Hydroxyl group-containing (meth)acrylate polymer (1)
The blending ratio is in the range of 1 to 40% by weight, more preferably 2 to 3% by weight in the total of the thermosetting resin (It) and the polymer (11).
It is in the range of 0% by weight. If the amount is less than 1% by weight, the shrinkage reduction effect will not be sufficient, and if the amount exceeds 40% by weight, the properties of the thermosetting resin will be impaired, which is not preferable.

When curing the low-shrinkage thermosetting resin composition of the present invention, benzoyl peroxide, methyl ethyl ketone peroxide, t-butyl peroxybenzoate, t-butyl peroxyoctoate, dicumyl peroxide, cumene hydroxy peroxide, etc. Oxide, cyclohexanone peroxide, lafuroyl peroxide, and other organic peroxides, and azobisisobutyronitrile and other nitriles capable of generating radicals are used as polymerization catalysts in an amount of 0.1 to 5% by weight based on the resin composition. If necessary, cobalt naphthenate, cobalt octenoate, manganese naphthenate, dimethylaniline, etc. are blended as polymerization accelerators in the range of 0.1 to 5% by weight based on the resin composition. This can be done according to known procedures.

(Effects of the Invention) The low shrinkage thermosetting resin composition of the present invention has the hydroxyl group-containing (meth)acrylate polymer (1) dissolved or extremely uniformly and stably dispersed in the composition.
It has excellent storage stability and can stably achieve a low shrinkage effect.

The low-shrinkage thermosetting resin composition of the present invention can be effectively used as is, but calcium carbonate, silica sand,
Fillers such as barium sulfate, carbon, glass powder, etc.; Reinforcing fiber materials such as glass fiber, asbestos, hemp, vinylon fiber, carbon fiber, etc.; Additives such as magnesium oxide, magnesium hydroxide, calcium hydroxide, calcium oxide, etc. Combined with adhesives, colorants, etc., bulk molding compounds (BMC) and sheet molding compounds (
SMC) can be used in various applications such as boats, septic tanks, toilet tanks, storage tanks, automobile parts, and electrical parts.

For example, in the case of BMC, the resin composition of the present invention is mixed with calcium carbonate, magnesium oxide, chopped strands, colorant, zinc stearate, and curing catalyst in a mixer, and the calculated amount is charged into a mold. , which is heated and pressurized to polymerize and harden to form a molded product. Also, in the case of SMC,
The resin composition of the present invention is thoroughly mixed with a thickener, a mold release agent, a polymerization catalyst, and a filler to form a relatively viscous liquid mixture, and an appropriate amount of the resin composition is impregnated into a preformed glass fiber sheet. The viscosity is increased to such an extent that it disappears to form a sheet in the shape of fresh bread, and a total of x amount of the sheet is charged into a mold, and the sheet is heated and pressed to polymerize and harden to form a molded product.

The molded product thus obtained has excellent performance such as excellent surface smoothness and gloss, no uneven color, and very little molding shrinkage, so there is no distortion or cracking. Another feature is that there is no mold staining during molding.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples and Reference Examples, but the present invention is not limited to these Examples. In addition, all parts and parts in each example mean parts by weight and weight % unless otherwise specified.

Reference Example 1 In a reaction vessel equipped with a thermometer and a stirrer, 232 parts of 2-hydroxyethyl acrylate, 0.07 part of hydroquinone monomethyl ether as a polymerization inhibitor, and 12- as a catalyst were placed in a reaction vessel equipped with a thermometer and a stirrer.
After adding 2.3 parts of tungstophosphoric acid, the temperature was heated to 80°C for 7.
It was held for 5 hours. After the reaction was completed, 12 parts of powdered magnesium silicate as an adsorbent was added, stirred at 40°C for 30 minutes, and purified by pressure filtration.
) reaction product as a colorless transparent liquid (228 parts (yield 98.3)
%) was obtained.

As a result of NMR analysis, the amounts of acryloyl groups and hydroxyl groups present were the same equivalent, and the average molecular weight by GPC was 401. Furthermore, IR and NMR.

From the GPC analysis results, the reaction product (hereinafter referred to as hydroxyl group-containing acrylate oligomer (1)) is
It was found to be a hydroxyl group-containing acrylate oligomer with the following structure.

Reference Example 2 A reaction vessel similar to Reference Example 1 was charged with 260 parts of 2-hydroxypropyl acrylate, 0.08 parts of hydroquinone monomethyl ether as a polymerization inhibitor, and 2.6 parts of 12-tungstophosphoric acid as a catalyst, and then heated at 100°C. It was kept for 4 hours.

After the reaction is completed, adsorbent powder magnesium silicate 13
After stirring at 40° C. for 30 minutes, purification was performed by pressure filtration to obtain 253 parts (yield: 97.3%) of a reaction product as a colorless transparent liquid with a color number (APHA) of 10. N.M.
As a result of analysis with R, the abundance of acryloyl groups and hydroxyl groups was the same equivalent, and the average molecular weight by GPC was 3.
It was 78. Furthermore, the results of KIR, NMR, and GPC analysis revealed that the reaction product (hereinafter referred to as hydroxyl group-containing acrylate oligomer (2)) was a hydroxyl group-containing acrylate oligomer having the following structure.

Reference Example 3 After charging 232 parts of 2-hydroxyethyl acrylate, 0.07 parts of hydroquinone monomethyl ether as a polymerization inhibitor, and 466 parts of 12-tungstosilicic acid as a catalyst into the same reaction vessel as in Reference Example 1, the mixture was heated to 80°C for 10 hours. I kept it.

After the reaction is completed, adsorbent powdered magnesium silicate 12
After stirring at 40°C for 30 minutes, purification was performed by pressure filtration to obtain 227 parts of the reaction product as a colorless transparent liquid with a color number (APHA) of 10 (yield: 97.8; average molecular weight by GPC: 1098). Furthermore, IR%NMR1GP
From the analysis results of C, it was found that the reaction product (hereinafter referred to as hydroxyl group-containing acrylate oligo Y- (31)) was a hydroxyl group-containing acrylate oligomer having the following structure.

Reference Example 4 In a reaction vessel similar to Reference Example 1, 260 parts of 2-hydroxyethyl methacrylate was used as a polymerization inhibitor and kept at 100°C for 4 hours. After the reaction was completed, 260 parts of water was added, stirred at room temperature, allowed to stand, and the aqueous layer (2 parts) was removed.
By keeping at 5o0c for 30 minutes under reduced pressure of mHg,
As a result of removing water and some of the remaining raw materials, the number of colors (A
102 parts (yield: 39.2%) of a colorless transparent liquid reaction product of PHA) 10 was obtained. The reaction product (hereinafter referred to as hydroxyl group-containing methacrylate oligomer (4)) was analyzed by IR and NMR.

As a result of GPC analysis, the abundance of methacryloyl groups and hydroxyl groups was the same, and the average molecular weight was 297.
was found to be a hydroxyl group-containing methacrylate oligomer with the following structure.

Reference Example 5 400 parts of water was charged into a reaction vessel equipped with a thermometer, a stirrer, a nitrogen gas introduction tube, a reflux condenser, and a dropping funnel, and while stirring, partial saponification with a degree of saponification of 87 to 89 and a degree of molar polymerization of 500 was carried out. 3 parts of polyvinyl alcohol was added and dissolved. Next, a monomer mixture consisting of the hydroxyl group-containing acrylate oligomer obtained in Reference Example 1 (1120 parts, 20 parts of butyl acrylate, 58 parts of methyl methacrylate, 2 parts of trimethylolpropane trimethacrylate, and 1 part of benzoyl peroxide) was then added thereto. The temperature was raised to 75°C after the atmosphere was replaced with nitrogen.The initiation of the reaction was confirmed by the generation of polymerization heat, and the reaction was further continued at 80°C for 3 hours to form a suspension of the hydroxyl group-containing (meth)acrylate polymer (1). A liquid was obtained with a polymerization rate of 99.3.

The polymer cake was removed by filtration, and the cake was
After drying in a hot air dryer at 6° C. for 5 hours, the mixture was ground in a hammer mill to obtain a white powdery hydroxyl group-containing (meth)acrylate polymer (1) that passed through 50 meshes.

Reference Example 6 In Reference Example 5, a monomer consisting of 7 m of the hydroxyl group-containing acrylate oligomer (2) obtained in Reference Example 2, 86 parts of butyl methacrylate, 5 parts of ethyl acrylate, 2 parts of divinylbenzene, and 1 part of benzoyl peroxide was used. A hydroxyl group-containing (meth)acrylate polymer (
A suspension of 2) was obtained.

The polymerization rate was 99.5%.

Next, the same filtration, drying, and pulverization as in Reference Example 5 were performed to obtain a white powdery hydroxyl group-containing (meth)acrylate polymer (2) that passed through 50 meshes.

Reference Example 7 In Reference Example 5, a monomer consisting of 3110 parts of the hydroxyl group-containing acrylate oligomer f obtained in Reference Example 3, 44 parts of butyl methacrylate, 44 parts of styrene, 2 parts of trimethylolpropane trimethacrylate, and 1 part of benzoyl peroxide was used. A suspension of the hydroxyl group-containing (meth)acrylate polymer (3) was obtained in exactly the same manner as in Example 5 except that the mixture was used. The polymerization rate was 99.
It was 2%.

Next, the same filtration, drying, and pulverization as in Reference Example 5 were performed to obtain a white powdery hydroxyl group-containing (meth)acrylate polymer (3) that passed through 50 meshes.

Reference Example 8 Xyl group-containing ≠ acrylate oligomer (reference except that a monomer mixture consisting of 4 parts 5 parts, 34 parts butyl acrylate, 50 parts styrene, 1 part trimethylolpropane trimethacrylate, and 1 part benzoyl peroxide) was used. A suspension of hydroxyl group-containing (meth)acrylate polymer (4) was obtained in exactly the same manner as in Example 5. The polymerization rate was 99.
It was 6%.

Next, the same filtration, drying, and pulverization as in Reference Example 5 were performed to obtain a white powdery hydroxyl group-containing (meth)acrylate polymer (4) that passed through 50 meshes.

Example 1 50 parts of isophthalic acid, 70 parts of maleic anhydride, 34 parts of ethylene glycol and 38 parts of propylene glycol were subjected to an esterification reaction at 200'C in a nitrogen stream for 24 hours to obtain an unsaturated polyester having an acid value of 20.

40.6 parts of this unsaturated polyester and 50.4 parts of styrene
parts were blended to obtain an unsaturated polyester resin (hereinafter referred to as unsaturated polyester resin (1)).

Next, 9 parts of the droxyl group-containing (meth)acrylate polymer (1) obtained in Reference Example 5 was mixed with 11,100 parts of this unsaturated polyester resin to form a low-shrinkage thermosetting resin composition of the present invention. (Hereinafter, this will be referred to as resin composition (1).) was obtained.

100 parts of t-butylperoxy and calcium carbonate were added to the obtained resin composition (1) and stirred to form a paste. Furthermore, by mixing 1.0 part of magnesium oxide with this paste and using a 9-impregnating solution, 7 pieces of glass fiber with a length of 25
It was impregnated with 0.7 parts, formed into a sheet between two sheets of polyethylene, and aged at 40° C. for 40 hours to form SMC. This S
M C was placed in a mold of 300 birds in size x 300, at a temperature of 140℃ and a pressure of 50kl. Press molding was performed for 4 minutes under molding conditions of /i to obtain a flat plate molded product with a thickness of 2n. This SM
When the molding shrinkage rate of C was measured based on JIS K 6911 K, the shrinkage was 0.06%. In addition, the gloss of the surface of the molded product was evaluated by calculating the reflectance (%) at a measurement angle of 60 degrees using a surface gloss needle, and it was 85.6%.
Met. Furthermore, the color unevenness of the molded product and the staining of the mold were observed with the naked eye, and evaluated in four stages: ◎ to ○ to Δ to ×.

The results are summarized in Table 1.

Examples 2 to 4 Hydroxyl group-containing (meth)acrylate polymers (2) obtained in Reference Examples 6 to 8 instead of hydroxyl group-containing (meth)acrylate polymer (1) in Example 1
The low shrinkage i thermosetting resin compositions of the present invention (hereinafter referred to as resin compositions (2) to (4), respectively) were prepared in the same manner as in Example 1, except for using each of (4). Obtained.

Using each of the obtained resin compositions (2) to (4), SMC was formed in the same manner as in Example 1, molded products were made, and the performance was evaluated. The results are summarized in Table 1.

Comparative Examples 1-2 Hydroxyl group-containing (meta)T-2 in Example 1)
A comparative resin composition (hereinafter referred to as this) was prepared in the same manner as in Example 1, except that a commercially available polyvinyl acetate-based low shrinkage agent (manufactured by Nippon Gosei Kagaku Kogyo ■, Gosenil NZ-5) was used. Comparative resin compositions (1) to (2) respectively
That's what it means. ) was obtained.

Using each of the obtained comparative resin compositions (1) and (2), SMC was produced in the same manner as in Example 1, and molded products were also produced, and the performance was evaluated. The results are summarized in Table 1.

Table 1 (Note 1) Measured according to JIS K 69] 1 (- indicates expansion) (Note 2) Reflectance at a measurement angle of 60 degrees (Note 3) ◎: No color unevenness ○: Slight color unevenness Yes Δ: There is color unevenness The composition has a lower molding shrinkage rate than conventional resin compositions using low-shrinkage agents, does not stain the mold during molding, and provides a molded product with high surface gloss without uneven coloring. It is.

Example 5 The resin composition (1) obtained in Example 1 was thoroughly stirred using a homomixer, and then allowed to stand at room temperature to evaluate the storage stability of the resin composition (1). The evaluation method was to measure the number of days from when the product was allowed to stand until it separated into two layers. The evaluation results are shown in Table 2.

Comparative Examples 3 to 4 Comparative Example 1 was used instead of resin composition (1) in Example 5.
Comparative resin compositions (1) and (2) obtained in and 2
Storage stability was evaluated in the same manner as in Example 5, except for using each of the following. The evaluation results are shown in Table 2.

Table 2 As is clear from Table 2, the resin composition of the present invention has good affinity for the thermosetting resin of the hydroxyl group-containing (meth)acrylate polymer used for low shrinkage, and is suitable for use. It has excellent workability during storage and storage.

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, in the formula, R is a hydrogen atom or a methyl group, which may be the same or different, and Z is Hydroxyl group-containing (meth)acrylate oligomers (which are divalent organic groups having 2 to 20 carbon atoms and may be the same or different, and n is an integer of 1 to 100) ( A) and, if necessary, the oligomer (A
) and a thermosetting resin (II) and a hydroxyl group-containing (meth)acrylate polymer (I) obtained by polymerizing a monomer (B) copolymerizable with a thermosetting resin (II). resin composition.