JPS6210538B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a highly fluidized unsaturated polyester resin composition, and more specifically to an unsaturated polyester resin composition obtained by adding a compound having a large fluidizing effect.

Conventionally, unsaturated polyester resins have been used as thermosetting resins in a wide variety of molding materials, from non-FRP applications to FRP, premixes, BMC, and SMC. The unsaturated polyester mentioned here refers to a linear polyester alkyd having an unsaturated group obtained by esterifying a saturated dicarboxylic acid, its anhydride, or its dialkyl ester with an unsaturated carboxylic acid, its anhydride, and glycol, and a vinyl monomer. Alternatively, it refers to a substance dissolved in a copolymerizable monomer such as an allyl monomer. While the polymerization and curing properties, fluidity, pot life, etc. of unsaturated polyester resins are adjusted according to their various uses, additives such as reinforcing agents, fillers, pigments, and mold release agents are required. used accordingly. Polymerization hardening characteristics, fluidity, pot life, etc. depend on molding conditions,
Although it is adjusted depending on the molding method and molding procedure, it has a significant impact on the processability, workability, productivity, etc. of unsaturated polyester resin, and the adjustment method and additions for adjustment are important. Many ideas and innovations have been made regarding agents. For example, with regard to the fluidity of unsaturated polyester resins, various things are known about increasing their viscosity, but little is actually known about reducing their viscosity, that is, increasing their fluidity.

From the viewpoint of increasing the viscosity of unsaturated polyester resin, that is, making it less fluid, methods include increasing the concentration of unsaturated polyester alkyd by reducing the amount of copolymerizable monomer, or adding fillers such as talc and calcium carbonate. There is. Therefore, one possible method for making unsaturated polyester resin highly fluid, that is, reducing its viscosity, is to increase the amount of copolymerizable monomer and lower the concentration of unsaturated polyester alkyd. If the body increases, not only the physical properties of the molded product will deteriorate significantly, but also the processability of the unsaturated polyester resin will deteriorate.
Workability also decreases. In particular, if the content of the copolymerizable monomer exceeds 50%, the shrinkage rate of the unsaturated polyester resin increases, causing whitening in molded products containing fillers and reinforcing agents.

On the other hand, it is also possible to reduce the molecular weight of the unsaturated polyester alkyd or to change the constituent components of the unsaturated polyester alkyd to raw materials that lower the viscosity, but such methods do not allow for the formation of unsaturated polyester resin molded products. This is undesirable because the physical properties are significantly deteriorated.

The present invention relates to a method for making an unsaturated polyester resin highly fluid without increasing the molecular weight or the constituent components of the unsaturated polyester alkyd or the amount of the copolymer monomer. That is, it is a highly fluidized unsaturated polyester resin containing a copolymerizable monomer solution of an unsaturated polyester alkyd and a pentaerythritol triester compound in an amount of 3 parts by weight or more based on the resin.

The present invention will be explained in more detail below.

The unsaturated polyester resin referred to in the present invention is a solution obtained by mixing an unsaturated polyester alkyd with a copolymerizable monomer, as described above. The unsaturated polyester alkyd is produced by an esterification reaction using a saturated dicarboxylic acid, its anhydride, or its dialkyl ester, an unsaturated dicarboxylic acid, its anhydride, and glycol as raw materials. Saturated dicarboxylic acids, their anhydrides, or dialkyl esters thereof used as raw materials include phthalic anhydride, isophthalic acid, terephthalic acid, dimethyl terephthalate, naphthalene dicarboxylic acid, adipic acid, etc., and unsaturated dicarboxylic acids or their anhydrides. Examples include fumaric acid, maleic anhydride,
Itaconic acid, etc. On the other hand, examples of glycols include ethylene glycol, 1,3-butylene glycol, 1,4-butanediol, diethylene glycol, hydrogenated bisphenol A, and alkylene oxide adducts of bisphenol A. Such unsaturated polyester alkyds preferably have a melting point of room temperature or higher. Furthermore, when solid unsaturated polyester alkyd is pulverized, the particle size of the pulverized product is preferably smaller than 10 meshes in practical terms.

The copolymerizable monomer which is one of the main components is a vinyl monomer or an allyl monomer such as styrene, vinyltoluene, divinylbenzene, monochloroethylene, t-butylstyrene,
Examples include methyl acrylate, methyl methacrylate, diallyl phthalate, diallyl fumarate, and triallyl cyanurate.

The pentaerythritol triester compound used in the present invention is prepared by preparing pentaerythritol using a conventional method using higher fatty acids such as capric acid, caprylic acid, lauric acid, mystylic acid, palmitic acid, stearic acid, and behemic acid as the acid component. It is triesterized.

The above unsaturated polyester alkyd, copolymerizable monomer, and pentaerythritol triester compound are mixed together with additives added as necessary, such as a polymerization initiator, reinforcing agent, filler, mold release agent, and pigment. There is no problem even if you mix it by hand.

The unsaturated polyester resin compositions of the present invention are particularly useful in the formulation of dry primics.

For example, in the case of dry premixes, the mixing ratio of unsaturated polyester alkyd and copolymerizable monomer and the mixing ratio of additives such as polymerization initiators, reinforcing agents, fillers, and mold release agents follow conventional methods, but at the same time the resin 3 parts by weight or more of the pentaerythritol triester compound may be added. The unsaturated polyester resin composition obtained in this manner significantly increases fluidity represented by spiral flow and improves moldability without changing polymerization curing characteristics or pot life. Moreover, it has the advantage that the molding shrinkage rate of the obtained molded product is reduced, the dimensional accuracy is improved, and the tensile strength, flexural modulus, etc. are less likely to be lowered.

EXAMPLES Next, the present invention will be specifically explained using Examples, but the present invention is not limited to these Examples.

In the examples, parts are simply parts by weight based on 100 parts by weight of the unsaturated polyester alkyd and copolymerizable monomer. The fluidity is EMMI-1, 66, the polymerization hardening properties are the values measured with JSR model Cyulastometer made by Japan Synthetic Rubber, and the physical properties of the molded product are JISK-6911.
This is the value measured according to.

Example A solid unsaturated polyester alkyd having an acid value of 18 was obtained using terephthalic acid and fumaric acid as raw materials according to a conventional method. The melting point of the unsaturated polyester alkyd obtained was 88°C, and this alkyd was ground at room temperature.
It was crushed to a size of 20 mesh or more. The weight ratio of this pulverized product to diallyl phthalate monomer as a copolymerizable monomer was 75:25, and the pentaerythritol triester compound and other additives such as a polymerization initiator had the following composition. . However, the pentaerythritol triester compound was esterified using stearic acid as a fatty acid raw material according to a conventional method, and had an acid value of 4.7, a saponification value of 169, and a melting point of 58°C.

Unsaturated polyester alkyd 75 parts Diaryl phthalate monomer 25 parts Dicumyl peroxide 1 part Particle size 1-10 μm Calcium carbonate 250 parts Particle size 0.2-1.0 mm Calcium carbonate 150 parts Glass chopped strand 6 mm fiber length 50 parts Zinc stearate 5 parts pentaerythritol triester
0, 1, 3, 5, 7, 10 parts The above compositions were kneaded together to form an unsaturated polyester resin composition.

In addition, as a comparative example instead of the above pentaerythritol triester compound, an unsaturated polyester using wax A, stearyl alcohol B, ester C of stearic acid and stearyl alcohol, trioctyl trimellitate D, behenic acid monoglyceride E, and benzyl alcohol F was used. A resin composition was also prepared.

Figure 1 shows the measured spiral flow values and the corresponding amounts (parts) of the pentaerythritol triester compound added when the various unsaturated polyester resin compositions mentioned above were transfer-molded at 160°C and 40 kg/ ^cm2 . FIG. 3 is a characteristic diagram showing the relationship between the two in relation to Comparative Examples A to F.

Figure 2 shows the measured molding shrinkage rates of molded products obtained by compression molding the above various unsaturated polyester resin compositions at 160°C to 5 mm, and the corresponding amounts (parts) of pentaerythritol triester compound added. FIG. 3 is a characteristic diagram showing the relationship between the following and Comparative Examples A to F.

Figure 3 shows the above unsaturated polyester resin composition.
Comparative Examples ^A ~ It is a characteristic diagram shown in relation to F.

Furthermore, the gelation time and curing time at 150 to 170°C of the unsaturated polyester resin composition according to the present invention are each 0.1 as in the case of the resin composition not containing the pentaerythritol triester compound.
~0.3min, 1.8~2.9min.

[Brief explanation of the drawing]

Figures 1 to 3 show the copolymerizable monomer solution of unsaturated polyester alkyd, which is an example of the present invention, and the fluidity of the resin composition when pentaerythritol triester is added to the resin, and the physical properties of the molded product. It is a characteristic diagram showing the effect of.

Claims (1)

[Claims] 1. A highly fluid unsaturated polyester resin composition comprising a copolymerizable monomer solution of an unsaturated polyester alkyd and a pentaerythritol triester compound in an amount of 3 parts by weight or more based on the resin.