JPH0570676A - Unsaturated polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of shortening the curing time without deteriorating the quality of products by blending a composition containing a filter in a specific unsaturated polyester resin with specific two kinds of organic peroxides at a specified ratio. CONSTITUTION:The objective composition is obtained by blending (A) a composition, prepared by blending (i) 25-46wt.% unsaturated polyester resin with (ii) 34-63wt.% vinyl monomer for cross-linking, (iii) 6-25wt.% polymer for preventing shrinkage and (iv) 96-240wt.% filler and having 3.0-5.6mol/dm<3> concentration of its unsaturated double bonds with (B) a mixture of (i) 0.02-0.10 pt.wt. (in an amount expressed in terms of active oxygen) organic peroxide (or its mixture) having 50 to <85 deg.C temperature of 10hr half-life with (ii) 0.02-0.10 pt.wt. (in an amount expressed in terms of the active oxygen) organic peroxide (or its mixture) having 85-110 deg.C temperature of 10hr half-life. The total amount of the organic peroxides is 0.06-0.16 pt.wt. The difference between the maximum and the minimum in the respective temperatures of 10hr half-life is >=10 deg..

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 which can shorten the curing time without deteriorating the quality of products.

[0002]

2. Description of the Related Art Unsaturated polyester resins obtained by dissolving a vinyl monomer for crosslinking such as styrene monomer in unsaturated polyester are widely used as resins for producing FRP molded products.

However, this unsaturated polyester resin is
Molding shrinkage is large during thermosetting, which often causes molding failure. For example, when a sheet molding compound (SMC) formed by impregnating an unsaturated polyester resin mixed with a curing catalyst with glass fiber is hot press-molded to produce an FRP molded product such as a bath, the FRP is caused by molding shrinkage. Surface defects such as glass fiber eyes appearing on the surface of the molded product and clouding occur.

Conventionally, in order to improve the molding shrinkage during thermosetting, an unsaturated polyester resin is generally blended with a shrinkage-preventing polymer comprising a thermoplastic polymer such as polystyrene or polyethylene, and the molding is generally performed at 120 to 180 ° C. Has been done. In this case, the thermoplastic polymer expands due to the heat generated when the unsaturated polyester resin cures, and the unsaturated polyester resin cures in a state where this expansion is maintained, whereby the molding shrinkage is improved and there is no surface defect. Good quality product is obtained.

As the curing catalyst, a high temperature curing type curing catalyst generally composed of an organic peroxide, such as t-butylperoxybenzoate or t-butylperoxy-2 is used.
-Ethyl hexanoate etc. are used.

Recently, these molded articles are required to have good quality and high productivity. In order to improve productivity, a method of shortening the curing time is usually adopted. Then, as a curing catalyst for shortening the curing time, a combination of the above-mentioned high temperature curing type curing catalyst with a room temperature curing type curing catalyst is used. Examples of the room temperature curing type curing catalyst include methyl ethyl ketone peroxide and methyl isobutyl ketone peroxide.
Those to which a metal ion-based accelerator such as cobalt naphthenate is added are widely used.

[0007]

However, in such a conventional method, as the curing time is shortened, the molding shrinkage is not sufficiently improved, and the smoothness of the surface is deteriorated. In addition, there is a problem that a product formed by using a curing catalyst containing a metal ion-based accelerator such as cobalt naphthenate discolors remarkably in hot water and cannot be used in, for example, a bath.

In addition, when the resin composition does not flow sufficiently during thermoforming due to curing progressing during compounding of the resin, storage of the resin composition, or storage of the sheet molding compound, molding becomes difficult. There is also.

The present invention solves the above problems, and an object of the present invention is to provide an unsaturated composition capable of shortening the curing time without deteriorating product quality such as surface smoothness due to molding shrinkage. It is to provide a polyester resin composition.

[0010]

In order to achieve the above object, the unsaturated polyester resin composition of the present invention is constructed as follows.

That is, 100 parts by weight of unsaturated polyester resin comprising 25 to 46% by weight of unsaturated polyester, 34 to 63% by weight of vinyl monomer for crosslinking, and 6 to 25% by weight of polymer for preventing shrinkage (total 100% by weight). 96 to 240 parts by weight of the filler are added to the mixture, and the concentration of unsaturated double bonds is 3.0 to 5.
A composition is prepared which is 6 mol / dm ³ .

The composition has a 10-hour half-life temperature of 0.02 to 0.10 parts by weight in terms of active oxygen, alone or as a mixture A of organic peroxides having a 10-hour half-life temperature of 50 to less than 85 ° C. Organic peroxide B at 85-110 ℃ is 0.02 in active oxygen equivalent.
.About.0.10 parts by weight.

Moreover, the total amount of A and B is 0.06 to 0.16 parts by weight in terms of active oxygen, which is 10% of the organic peroxide used.
The maximum and minimum time half-life temperatures are selected to be more than 10 ° C apart.

The unsaturated polyester used in the present invention is
Unsaturated dibasic acids such as (anhydrous) maleic acid and fumaric acid, or some of which are substituted with saturated dibasic acids such as (anhydrous) phthalic acid and isophthalic acid, and propylene glycol, neopentyl glycol, hydrogenated bisphenol It is obtained by polycondensation reaction with a divalent alkole such as.

The average molecular weight of this unsaturated polyester is
It is generally 800-5000, and its acid value is generally 8-20 m.
Although gKOH / g is used, those outside this range can also be used. Techniques for producing such unsaturated polyesters are well known.

As the crosslinking vinyl monomer, vinyl monomers such as styrene, α-methylstyrene, vinyltoluene and methylmethacrylate which are soluble in the above unsaturated polyester are used. Such crosslinking vinyl monomers are well known.

As the shrinkage-preventing polymer, thermoplastic polymers such as polystyrene, polyethylene, polyurethane, acrylic resin, saturated polyester and styrene-butadiene block copolymer are used. Such shrinkage-preventing polymers are also well known.

In the present invention, the unsaturated polyester composed of 25 to 46% by weight, the crosslinking vinyl monomer 34 to 63% by weight, and the shrinkage preventing polymer 6 to 25% by weight (total 100% by weight). Polyester resin is used. This quantitative range has been determined by the present inventor through various experiments and determined so as to shorten the curing time and obtain good quality.

96 to 240 parts by weight of a filler is mixed with 100 parts by weight of such an unsaturated polyester resin. This filler is mainly used for increasing product strength, imparting flame retardancy, reducing cost and adjusting viscosity of the composition. The quantitative range has been determined by the inventor through various experiments and determined so that good quality can be obtained with shortening the curing time.

As the filler, calcium carbonate, talc, silica, clay, asbestos, glass powder or balloon, barium sulfate, aluminum hydroxide, antimony trioxide, etc. are used. As the filler, for example, a reinforcing fiber such as a glass fiber having a thickness of 8 to 50 μm and a length of 5 to 150 mm is also used. Such a reinforcing fiber is sometimes referred to as a reinforcing material in distinction from the former filler such as calcium carbonate, but is included in the filler in the present invention.

The unsaturated polyester resin composition of the present invention is usually used in the sheet molding compound (SM
Since it is used for FRP molding according to C) and the like, both the above-mentioned reinforcing fiber and filler are often mixed. In this case, the reinforcing fiber is generally mixed (impregnated) in an amount of 50 to 100 parts by weight with respect to 100 parts by weight of the unsaturated polyester resin.

The concentration of unsaturated double bonds in the composition thus prepared is 3.0 to 5.6 mol / dm ³ . The unsaturated double bond in this composition is present both in the residue of the unsaturated dibasic acid (having a dehydrated polycondensed structure) that is a component of the unsaturated polyester and in the vinyl monomer for crosslinking. To do.

Therefore, the number of moles of the residue of the unsaturated dibasic acid is calculated based on the unsaturated dibasic acid used for the synthesis of the unsaturated polyester, and the number of moles of the crosslinking vinyl monomer used is calculated, The concentration of unsaturated double bonds can be calculated by summing both moles and dividing by the total volume of the composition. When the concentration of the unsaturated double bond is less than 3.0 mol / dm ³ , the heat resistance of the molded product is lowered and it is not suitable for molding a bath or the like which requires heat resistance. On the other hand, when it exceeds 5.6 mol / dm ³ , the amount of the filler and / or the reinforcing material becomes small, so that the viscosity control of the composition, the strength of the molded product, the cost, etc. occur.

Further, a curing catalyst is added to the above composition. As the curing catalyst, in order to shorten the curing time and improve the productivity, an organic peroxide alone or a mixture A having a 10-hour half-life temperature of 50 to less than 85 ° C. and a 10-hour half-life temperature of 85 to An organic peroxide of 110 ° C. alone or in combination with the mixture B is used, and the maximum and minimum 10-hour half-life temperatures of the organic peroxides used are separated by 10 ° C. or more.

Here, the 10-hour half-life temperature represents the activity of the organic peroxide, and means the decomposition temperature at which the half-life (time when the amount of active oxygen becomes half of the initial time) becomes 10 hours. .. In this case, if a curing catalyst composed of an organic peroxide having a 10-hour half-life temperature lower than 50 ° C. is used, curing proceeds during storage of the resin composition, and a good FRP molded product cannot be obtained. On the other hand, when a curing catalyst composed of an organic peroxide having a 10-hour half-life temperature higher than 110 ° C. is used, the organic peroxide remains after curing and the molded product is likely to turn yellow.

When the maximum and minimum 10-hour half-life temperatures of both are closer than 10 ° C., the decomposition peaks of the organic peroxide are too close to each other, so that the amount of radicals generated is concentrated in one period. To do. As a result, the reaction rate in the latter stage of the polymerization reaction decreases, the amount of the crosslinking vinyl monomer remaining in the molded product increases, and the hardness and bending strength decrease. Moreover, the effect of shortening the curing time is also reduced.

The organic peroxides having a 10-hour half-life temperature of 50 to less than 85 ° C. alone or as a mixture A include 2,4-dichlorobenzoyl peroxide, o-methylbenzoyl peroxide and bis-3,5,5. -Trimethylhexanoyl peroxide, lauroyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide,
t-butylperoxypivalate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, di-t-butylperoxyhexahydroterephthalate, t-butylperoxyneohexa Noate, t-hexyl peroxypivalate, octanoyl peroxide, decanoyl peroxide, cumyl peroxy octoate, succinyl acid peroxide, acetyl peroxide, m-toluoyl peroxide, t-amyl peroxy-2. -Ethyl hexanoate, t-amyl peroxypivalate, etc. are mentioned. One or two or more are selected from them.

As the organic peroxide having a 10-hour half-life temperature of 85 to 110 ° C. alone or as a mixture B, methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, methylcyclohexanone peroxide, Tris-t. -Butylperoxytriazine, 1,1-di-t-butylperoxy-3,5-trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, 2,2-di-t-butylperoxybutane , 4,4-di-t-butylperoxyvaleric acid-n-butyl ester, di-t-butylperoxyazelaate, t-butylperoxy-3,3,5-trimethylhexanoate, t- Butyl peroxyacetate, t-butyl peroxybenzoate, t-butyl peroxy isopropyl carbonate , T- butyl peroxy maleic acid, t- butyl peroxy laurate, t
-Butylperoxyallyl carbonate, 2,5-dimethyl-2,5-di-benzoylperoxyhexane, 2,2-
Di-t-butylperoxyoctane, peroxyhexane, di-t-butylperoxyisophthalate and the like can be mentioned. One or two or more are selected from them.

The blending amount of A and B is 0.02 to 0.10 parts by weight in terms of active oxygen equivalent, and A
The total amount of B and B is 0.06 to 0.16 parts by weight in terms of active oxygen equivalent. Here, the amount of active oxygen equivalent refers to the weight of the organic peroxide to be mixed and the active oxygen (-O) in the organic peroxide.
-) Means the value multiplied by the content rate. The active oxygen in the organic peroxide is not limited to one and may exist in plural.

When the compounding amount of A is less than the above range,
It takes a long time to start the reaction, and the curing is delayed. On the contrary, when the compounding amount of A is larger than the above range, pre-gelation occurs and the surface of the molded product deteriorates. On the other hand, if the blending amount of B is less than the above range, the residual amount of the crosslinking vinyl monomer in the molded product increases, and the hardness and bending strength decrease. On the other hand, if the blending amount of B is more than the above range, the organic peroxide remains after curing and the molded product tends to yellow.

When the total amount of A and B is less than the above range, the total amount of radicals generated becomes small, the polymerization reaction is not sufficient and the curing is delayed, or the curing is not completed completely. On the other hand, if the total amount of A and B is more than the above range, the radicals generated are excessive, pregelation occurs, the surface of the molded product may be deteriorated, or the molded product may yellow. In addition, the hot water resistance of the molded product also decreases.

Further, if necessary, conventional chemical thickeners, release agents, stabilizers, colorants and the like are added in appropriate amounts. As the chemical thickener, for example, magnesium oxide, magnesium hydroxide or the like is used. As the release agent, for example, zinc stearate, calcium stearate or the like is used. Examples of pigments that can be used include titanium dioxide, carbon black, phthalocyanine blue, and red iron oxide. As the stabilizer, for example, hydroquinone, parabenzoquinone, or the like is used.

Thus, the unsaturated polyester resin composition of the present invention is obtained. Using the unsaturated polyester resin composition of the present invention, for example, by the known SMC method, F
In order to manufacture an RP molded product, first, this unsaturated polyester resin composition (in which case, the glass fiber that is the reinforcing material is not blended) is cut into glass fibers such as glass roving in the SMC manufacturing process. (Reinforcement material) is impregnated and sandwiched by a support film to produce a sheet molding compound (SMC). And this S
By hot-press molding MC, it is molded into FRP molded products such as bathtubs and waterproof pans.

The unsaturated polyester resin composition of the present invention is prepared by using the above-mentioned sheet molding compound (S
It can be used not only for the production of FRP molded products using MC) as a material, but also for the production of FRP molded products by other molding methods. It is also possible to manufacture a molded product without using reinforcing fibers.

[0035]

The unsaturated polyester resin composition of the present invention is used, and this is subjected to, for example, 120 to 18 by a hot press molding method or the like.
When thermoforming at 0 ° C., the organic peroxide in the resin composition decomposes at a rate according to the heating temperature to generate radicals. In this case, the rate of the polymerization reaction is determined by the temperature of a certain region, the radical concentration thereof, and the concentration of unsaturated double bonds in the resin composition.

When radicals generated by the organic peroxides alone or in the mixture A having a 10-hour half-life temperature of 50 to less than 85 ° C. initiate the polymerization reaction and the exothermic heat of polymerization becomes non-negligible, this organic peroxide is generated. Compound A rapidly decomposes, and the temperature of the resin composition rapidly rises.

As a result, the 10-hour half-life temperature was 85 to 110 ° C.
Decomposition of the organic peroxide alone or the mixture B rapidly increases to generate radicals for polymerizing the unsaturated double bond which could not be polymerized only by the radicals generated by the organic peroxide A. .. Therefore, the polymerization reaction is carried out rapidly from the initial stage to the final stage, and the shrinkage-preventing polymer is swelled well.

[0038]

EXAMPLES Examples and comparative examples of the present invention will be shown below. Example 1 Unsaturated polyester comprising 13.9 parts by weight of maleic acid residue, 2.1 parts by weight of isophthalic acid residue, 9.2 parts by weight of hydrogenated bisphenol A residue, 3.9 parts by weight of neopentyl glycol residue, and 8.0 parts by weight of propylene glycol residue. 37.1 parts by weight, 52.4 parts by weight of styrene monomer, styrene polymer
10.5 parts by weight, 122 parts by weight of calcium carbonate and 5.0 parts by weight of zinc stearate were mixed.

To this mixture, 0.019 parts by weight of parabenzoquinone, 0.56 parts by weight of t-butylperoxy-2-ethylhexanoate having a 10-hour half-life temperature of 74 ° C. (0.041 parts by weight in terms of active oxygen amount), 10 hours 0.45 parts by weight of t-butylperoxyisopropyl carbonate having a half-life temperature of 97 ° C. (0.041 parts by weight in terms of active oxygen amount) was mixed, and 1.0 part by weight of magnesium oxide was further mixed to thicken the composition. Was placed in a mold at 145 ° C. and pressed to form a plate having a thickness of 8 mm.

A pressing time of 100 seconds was sufficient for molding. In addition, no discoloration was observed in this plate-shaped molded product even when immersed in hot water at 95 ° C for 300 hours. The total volume of all the compositions excluding the above organic peroxide was 144 dm ³ , and the unsaturated double bond concentration of the composition calculated from the unsaturated double bonds of the maleic acid residue and the styrene monomer was 4.7 mol / dm
^{Is 3} .

Example 2 As a curing catalyst, 0.63 parts by weight of lauroyl peroxide having a 10-hour half-life temperature of 61 ° C. (0.025 parts by weight in terms of active oxygen amount) and t-butylperoxy having a 10-hour half-life temperature of 74 ° C. -2-Ethylhexanoate 0.34 parts by weight (0.025 parts by weight in terms of active oxygen amount), t- with a 10-hour half-life temperature of 97 ° C
0.45 parts by weight of butyl peroxyisopropyl carbonate (0.039 parts by weight in terms of active oxygen amount) was used. Other than that was performed like Example 1.

A pressing time of 90 seconds was sufficient for molding. In addition, no discoloration was observed in this plate-shaped molded product even when immersed in hot water at 95 ° C for 300 hours. Example 3 Unsaturated polyester comprising 11.8 parts by weight of maleic acid residue, 1.8 parts by weight of isophthalic acid residue, 7.8 parts by weight of hydrogenated bisphenol A residue, 3.3 parts by weight of neopentyl glycol residue, and 6.8 parts by weight of propylene glycol residue. 31.5 parts by weight, 47.2 parts by weight of styrene monomer, styrene polymer
9.0 parts by weight, 121 parts by weight of calcium carbonate, 4.2 parts by weight of zinc stearate, and 12.3 parts by weight of a pigment such as titanium dioxide were mixed.

To this mixture, 0.030 part by weight of parabenzoquinone, 0.48 part by weight of t-butylperoxy-2-ethylhexanoate having a 10-hour half-life temperature of 74 ° C. (0.036 part by weight in terms of active oxygen amount), and 10 Time half-life temperature of 97 ℃ t-
0.39 parts by weight of butyl peroxyisopropyl carbonate (0.035 parts by weight in terms of active oxygen) is mixed, and 0.85 parts by weight of magnesium oxide is further mixed, and the length is 25.4 m.
After impregnating 78 parts by weight of glass fiber having a thickness of 13 μm and a thickness of 13 μm to increase the viscosity, it is put into a mold at 145 ° C. and pressurized to weigh 4.3 kg and have a thickness of 8
A mm planter was molded.

A pressing time of 100 seconds was sufficient for molding. The residual styrene monomer in the molded product at this time was 0.1.
It was less than weight%. The total volume of all compositions excluding the above organic peroxide was 175 dm ³ , and the unsaturated double bond concentration of the composition calculated from the unsaturated double bonds of the maleic acid residue and the styrene monomer was , 3.4 mol / dm ³ .

Example 4 13.0 parts by weight of maleic acid residue, 2.0 parts by weight of isophthalic acid residue, 9.8 parts by weight of hydrogenated bisphenol A residue, 3.6 parts by weight of neopentyl glycol residue, 7.5 parts by weight of propylene glycol residue 35.9 parts by weight of unsaturated polyester, 44.0 parts by weight of styrene monomer, styrene polymer
5.7 parts by weight, polyethylene 4.1 parts by weight, calcium carbonate
115 parts by weight, 4.1 parts by weight of zinc stearate, and 11.5 parts by weight of a pigment such as titanium dioxide were mixed.

To this mixture, 0.017 part by weight of parabenzoquinone, 0.55 part by weight of t-butylperoxy-2-ethylhexanoate having a 10-hour half-life temperature of 74 ° C. (0.041 part by weight in terms of active oxygen amount), and Time half-life temperature of 97 ℃ t-
0.56 parts by weight of butyl peroxyisopropyl carbonate (0.051 parts by weight of active oxygen equivalent) were mixed, and 0.82 parts by weight of magnesium oxide was further mixed, and the length was 25.4 mm,
After impregnating 59 parts by weight of glass fiber having a thickness of 13 μm to increase the viscosity, the mixture was put into a mold at 145 ° C. and pressurized to form a bath having a weight of 20 kg and a thickness of 8 mm.

A pressing time of 100 seconds was sufficient for molding. In addition, no discoloration was observed in this bath-molded product even when immersed in hot water at 95 ° C for 300 hours. The total volume of all the compositions excluding the above organic peroxide was 166 dm ³ , and the unsaturated double bond concentration calculated from the unsaturated double bonds of the maleic acid residue and the styrene monomer was 3.5 mol / mol. It is dm ³ .

Example 5 38.1 parts by weight of unsaturated polyester consisting of 11.4 parts by weight of maleic acid residue, 7.9 parts by weight of isophthalic acid residue, 14.3 parts by weight of neopentyl glycol residue and 4.5 parts by weight of propylene glycol residue, and styrene monomer 43.1 parts by weight, 7.6 parts by weight of styrene polymer, 104 parts by weight of aluminum hydroxide, 4.3 parts by weight of zinc stearate, and 11.2 parts by weight of a pigment composed of titanium dioxide were mixed.

To this mixture were added 0.028 parts by weight of parabenzoquinone, 0.44 parts by weight of t-butylperoxy-2-ethylhexanoate having a 10-hour half-life temperature of 74 ° C. (0.033 parts by weight in terms of active oxygen amount), and 10 Time half-life temperature of 97 ℃ t-
0.35 parts by weight of butyl peroxyisopropyl carbonate (0.032 parts by weight in terms of active oxygen) was mixed, and 0.86 parts by weight of magnesium oxide was further mixed.
56 parts by weight of glass fiber of m and 14 μm in thickness were impregnated and thickened, and then put into a mold at 145 ° C. and pressurized to form a bath having a thickness of 8 mm.

A pressing time of 100 seconds was sufficient for molding. No discoloration was observed in this bathtub molded product even after immersion in hot water at 95 ° C for 300 hours. The total volume of all compositions excluding the above organic peroxide was 165 dm ³ , and the unsaturated double bond concentration calculated from the unsaturated double bonds of the maleic acid residue and the styrene monomer was 3.4 mol / dm 3. ^{Is 3} .

Comparative Example 1 As the curing catalyst, only 1.00 parts by weight of t-butylperoxybenzoate having a 10-hour half-life temperature of 105 ° C. (0.082 parts by weight in terms of active oxygen amount) was used. In addition, 0.019 parts by weight of parabenzoquinone was changed to 0.035 parts by weight. Other than that was performed like Example 1.

In this case, the pressurizing time required for molding was 165 seconds, which was longer than that of each example. .. Comparative Example 2 As the curing catalyst, only 1.78 parts by weight of t-butylperoxyisopropyl carbonate having a 10-hour half-life temperature of 97 ° C. (0.16 parts by weight in terms of active oxygen amount) was used. Also, no parabenzoquinone was used. Other than that, Example 1
I went the same way.

In this case, the pressing time required for molding was 110 seconds. However, in this case, pull gelation occurred, the surface smoothness of the plate-shaped molded product deteriorated, and fogging occurred. Comparative Example 3 As a curing catalyst, 0.45 parts by weight of t-butylperoxyisopropyl carbonate having a 10-hour half-life temperature of 97 ° C. (0.041 parts by weight in terms of active oxygen amount) and a 10-hour half-life temperature of 44 were used.
1.02 parts by weight of bis (4-t-butylcyclohexyl) peroxydicarbonate (0.041 parts by weight in terms of the amount of active oxygen) was used. In addition, 0.019 parts by weight of parabenzoquinone was changed to 0.020 parts by weight. Other than that was performed like Example 1.

In this case, the pressurizing time required for molding was 75 seconds, but curing began to proceed during the compounding of the resin, and the resin did not flow sufficiently during molding, making molding difficult. 20 ° C
It was cured after 1 week if it was stored in.

Comparative Example 4 As the curing catalyst, only 0.72 parts by weight of t-butylperoxy-2-ethylhexanoate having a 10-hour half-life temperature of 74 ° C. (0.053 parts by weight in terms of active oxygen amount) was used. Other than that was performed like Example 3.

In this case, the pressurizing time required for molding was 100 seconds, but the residual styrene monomer in the molded product was
It was 0.2% by weight or more. Even if the amount of t-butylperoxy-2-ethylhexanoate was increased from 0.72 parts by weight to 1.23 parts by weight (0.091 parts by weight in terms of active oxygen amount), the residual styrene monomer did not decrease. 30 molded products
A significant discoloration was observed when immersed in hot water for 0 hours. It is considered that this is because crosslinking is not sufficiently performed.

Comparative Example 5 As a curing catalyst, 0.49 parts by weight of methyl ethyl ketone peroxide (0.088 parts by weight in terms of the amount of active oxygen) having a 10-hour half-life temperature of 105 ° C. and 0.176 of a 6% cobalt naphthenate solution were used.
Parts by weight (0.011 parts by weight of cobalt naphthenate) were used. Other than that was performed like Example 4.

In this case, the pressurizing time required for molding was 100 seconds, but the composition not only hardened during storage, but the molded article showed a remarkable discoloration when immersed in hot water for 300 hours. Admitted.

Comparative Example 6 As a curing catalyst, 1.149 parts by weight of t-butylperoxy-2-ethylhexanoate (0.085 parts by weight in terms of active oxygen) having a 10-hour half-life temperature of 74 ° C. and 10-hour half-life 0.937 parts by weight of t-butylperoxyisopropyl carbonate (0.085 parts by weight in terms of active oxygen amount) having a temperature of 97 ° C. was used. Other than that was performed like Example 5.

In this case, the pressurizing time required for molding was 100 seconds, but the composition proceeded to cure during storage, and the molded article was observed to turn yellow when immersed in hot water for 300 hours. It was It is considered that this is because the residual amount of the organic peroxide is large.

[0061]

As described above, the unsaturated polyester resin composition of the present invention is formed by mixing the unsaturated polyester resin composed of the unsaturated polyester, the crosslinking vinyl monomer and the shrinkage-preventing polymer with the filler. The specific composition contains a curing catalyst composed of specific organic peroxides having different activities, and the action of the composition and the curing catalyst reduces the curing time of the composition to, for example, 100 seconds or less. It can be shortened and its productivity is improved. Moreover,
The function of the polymer for preventing shrinkage is sufficiently exerted, and a good FRP molded product without quality defects such as surface smoothness of the obtained product can be obtained.

Furthermore, since the unsaturated polyester resin composition of the present invention does not use a metal ion type curing accelerator as in the conventional case, it does not cause discoloration due to hot water and is used in an environment of hot water such as a bath. It is suitable for manufacturing FRP molded products. In addition, it can also be used to manufacture FRP molded products such as waterproof pans and automobile parts.

Claims (1)

[Claims] 1. An unsaturated polyester (25 to 46% by weight), a crosslinking vinyl monomer (34 to 63% by weight) and a shrinkage-preventing polymer (6).
To 100 parts by weight of unsaturated polyester resin consisting of 25 to 25% by weight (total 100% by weight), 96 to 240 parts by weight of filler is mixed, and the concentration of unsaturated double bond is 3.0 to 5.6 mol / dm.
^In the composition of ³ , the organic peroxide alone or the mixture A having a 10-hour half-life temperature of 50 to less than 85 ° C. is 0.02 to 0.10 parts by weight in terms of active oxygen.
An organic peroxide having a 10-hour half-life temperature of 85 to 110 ° C. alone or in a mixture B is contained in an amount of 0.02 to 0.10 parts by weight in terms of active oxygen, and the total amount of A and B is 0.06 in terms of active oxygen. Is 0.16 parts by weight, and the maximum and minimum of the 10-hour half-life temperature of the organic peroxide used are separated by 10 ° C. or more, and the unsaturated polyester resin composition.