JP3328968B2 - Unsaturated polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention has a long pot life,
The present invention relates to a fast-curing unsaturated polyester resin composition.

[0002]

2. Description of the Related Art FRP molding materials such as SMC and BMC are obtained by adding a thickening agent, a curing agent, a curing accelerator, a reinforcing agent, a filler, a low shrinkage agent, a release agent, an inhibitor, a vinyl mold to an unsaturated polyester resin. After mixing the monomers, they are made into a sheet, pellet, or bulk, respectively. Since these molding materials are suitable for mass production, they are cured and molded by various molding methods such as compression, transfer, injection and the like, and are now widely used industrially as automobile parts, electric parts, housing materials and the like. Conventionally, these FRPs are generally formed at a high temperature of 120 to 160 ° C. in consideration of productivity. As a curing agent for the FRP molding material, t-butyl peroxybenzoate is often used. However, recently, the demand for shortening the molding cycle has increased, and FR
Fast-curing curing agents have been used so that P molding materials can be molded in a short time. However, generally, a resin composition containing a fast-curing curing agent necessarily has a problem that the pot life is necessarily shortened. Pot life is the time during which SMC and BMC obtained by blending a curing agent and the like with an unsaturated polyester resin maintain a state in which the SMC and BMC can be used as a molding material without causing a change in viscosity or the like at the storage temperature. is there. There is a demand for a curing agent which has a practically long pot life and provides a fast-curing unsaturated polyester resin composition. To meet such a demand, Japanese Patent Publication No. 59-50689 discloses a 1,1-
A composition comprising bis (t-amylperoxy) 3,3,5-trimethylcyclohexane or 1,1-bis (t-amylperoxy) cyclohexane as a curing agent is disclosed. Japanese Patent Application Laid-Open No. 4-76006 discloses a composition containing a mixture of peroxyketal having a cyclic structure and t-butylperoxyisopropyl carbonate.

[0003]

SUMMARY OF THE INVENTION In order to improve the productivity and the storage property, an unsaturated polyester resin composition having a longer pot life and a faster curability than those of the above compositions is required. ing.

[0004]

Means for Solving the Problems The inventors of the present invention have studied over a long period of time for the purpose of developing an unsaturated polyester resin composition having the above-mentioned requirements, and as a result, by using a specific peroxyketal as a curing agent, Knowing that the above-mentioned object is achieved, the present invention has been completed. That is,
The present invention relates to an unsaturated polyester resin composition containing a curing agent, wherein the curing agent is

Embedded image A peroxyketal represented by the following formula:

In the present invention, specific examples of the peroxyketal represented by Chemical Formula 1 include, for example, 1,1-di-
t-butylperoxy-2-methylcyclohexane,
1,1-di-t-amylperoxy-2-methylcyclohexane, 1,1-di-t-hexylperoxy-2-
Methylcyclohexane, 1,1-di-t-octylperoxy-2-methylcyclohexane, 1,1-di-t-
Butyl peroxy-2-ethylcyclohexane, 1,1
-Di-t-butylperoxy-2-propylcyclohexane, 1,1-di-t-butylperoxy-2-isopropylcyclohexane, 1,1-di-t-butylperoxy-2-sec-butylcyclohexane and the like. .

[0006] These peroxyketals having a substituent at the 2-position have lower thermal decomposition temperatures than conventionally known peroxyketals having no substituent at the 2-position. The resin composition is
Fast curing speed. Generally, when the curing speed is high, the pot life is generally short, but surprisingly, the composition of the present invention has the unexpected feature of long pot life.

[0007] The peroxyketal used in the present invention is obtained by reacting the corresponding ketone with a t-alkyl hydroperoxide in the presence of a mineral acid catalyst such as sulfuric acid, phosphoric acid or perchloric acid.

In the present invention, the unsaturated polyester resin is obtained by blending a vinyl monomer with a conventionally known unsaturated polyester.
20 parts by weight and 20 to 80 parts by weight of a vinyl monomer. Examples of the vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, diallyl phthalate, alkyl acrylate and alkyl methacrylate. The unsaturated polyester is produced, for example, by condensing an α, β-unsaturated dibasic acid and a polyhydric alcohol with a saturated dibasic acid as required. Examples of unsaturated dibasic acids include maleic acid, maleic anhydride, fumaric acid, fumaric anhydride, and the like,
As the saturated dibasic acid, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride,
Succinic acid, adipic acid, sebacic acid and the like can be mentioned.
Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and 1,3-butylene glycol.

In the present invention, the compounding amount of the curing agent cannot always be specified by the kind of the unsaturated polyester resin and the combination of the additives.
0.01 g to 0.2 g as a peroxy bond with respect to 00 g.
Molar amounts are appropriate. If the amount is less than 0.01 mol, the curing of the composition is slow, and if it exceeds 0.2 mol, it is difficult to control the curing speed.

The composition of the present invention comprises reinforcing fibers such as glass fibers, chemical fibers, and polycrystalline fibers, magnesium oxide,
Thickeners such as silica and calcium hydroxide, low-shrinkage agents such as polystyrene and polyvinyl acetate, calcium carbonate,
Fillers such as clay and talc, and polymerization inhibitors such as benzoquinone, hydroquinone, and 2,6-di-t-butyl-p-cresol may be blended.

The composition of the present invention is molded by known means, particularly preferably by die molding such as press molding or injection molding, and its curing temperature is usually 90 to 160 ° C.
It is. If the temperature is lower than 90 ° C., the curing is slow, and if it exceeds 160 ° C., the heat shrinkage distortion is increased, which is not preferable.

[0012]

The unsaturated polyester resin composition of the present invention has a longer pot life and faster curing than conventional unsaturated polyester resin compositions, so that it has good storage properties and can be molded at a relatively low temperature. The industrial value is extremely high because the cycle can be shortened.

[0013]

Next, the present invention will be described in more detail by way of examples. In each example,% indicates% by weight. Abbreviations in the examples indicate the following compounds. BuMC: 1,1-di-t-butylperoxy-2-methylcyclohexane (purity 95%) HxMC: 1,1-di-t-hexylperoxy-2-
Methylcyclohexane (purity 94%) OcMC: 1,1-di-t-octylperoxy-2-
Methylcyclohexane (92% purity) BuIPC: 1,1-di-t-butylperoxy-2-
Isopropylcyclohexane (purity 95%) BuZ: t-butylperoxybenzoate (Nippon Oil & Fat Co., Ltd., Perbutyl Z, purity 99%) BuC: 1,1-di-t-butylperoxycyclohexane (Nippon Oil & Fat Co., Ltd.) AmC: 1,1-di-t-amylperoxycyclohexane (purity 95%) Bu3M: 1,1-di-t-butylperoxy-3,
3,5-trimethylcyclohexane (Nippon Oil & Fats Co., Ltd.)
BuI: t-butylperoxyisopropyl carbonate (manufactured by NOF Corporation, perbutyl I, 96% purity) HxI: t-hexylperoxyisopropyl carbonate (manufactured by NOF Corporation, perhexyl I) , Purity 95
%)

Example 1 BuMC was added as a curing agent to an unsaturated polyester resin for SMC (Polymer manufactured by Takeda Pharmaceutical Co., Ltd.) at a ratio of 0.1 mol of peroxide bond to 1 kg of resin, according to JIS.
A heat-curing test at 90 ° C. was performed by a method according to K-6901, and the pot life at 30 ° C. was measured. Table 1 shows the results. In Table 1, GT is the time to reach 95 ° C. after placing the sample in a 90 ° C. oil bath = gel time (min), C
T is also the time to reach the maximum temperature = curing time (min), P
ET represents the maximum temperature (° C.). The pot life indicates the time (hour) when the fluidity of the sample is partially lost.

Examples 2 to 4 and Comparative Examples 1 to 6 A heat curing test was carried out and the pot life was measured in the same manner as in Example 1 except that the curing agent was changed to the compound shown in Table 1. did. Table 1 shows the results.

[Table 1] From Examples 1 to 4 and Comparative Examples 1 to 6, the unsaturated polyester resin composition of the present invention in which the curing agent represented by Chemical Formula 1 was blended was compared with the composition in which the conventional curing agent was blended. It can be seen that the gelation time and the curing time are short and the pot life is long. Also, comparing the GT, CT, and pot life of Comparative Examples 2 to 6, it can be seen that the potting life of the curing agent of the present invention is relatively longer than that of GT, CT. Further, the composition of the present invention has a high exothermic temperature, indicating that the curing reaction is completely performed.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-109523 (JP, A) JP-A-61-21107 (JP, A) JP-A-2-55711 (JP, A) JP-A-4- 76006 (JP, A) JP-A-5-194621 (JP, A) JP-A-3-79616 (JP, A) JP-A-1-228957 (JP, A) JP-A-1-229020 (JP, A) JP-A-62-51665 (JP, A) JP-A-52-138587 (JP, A) JP-A-5-132510 (JP, A) JP-A-53-85876 (JP, A) JP-A-54-19907 (JP, A) JP-A-5-51422 (JP, A) JP-A-6-80708 (JP, A) JP-A-6-49130 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) C08F 283/00-283/01 C08F 290/00-290/14 C08F 299/00-299/08 C08F 4/00-4/38

Claims (1)

(57) [Claims] 1. An unsaturated polyester resin composition containing a curing agent, wherein the curing agent is: An unsaturated polyester resin composition, which is a peroxyketal represented by the following formula: