JPH038368B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a curable resin composition that has excellent impact resistance and is particularly suitable for obtaining a molding material that is solid at room temperature. [Technical background of the invention and its problems] In general, unsaturated polyester resin molding materials that are solid at room temperature in the form of granules or flakes are composed of solid unsaturated polyester resin, copolymerizable vinyl monomers, fillers, reinforcing agents, A mixture of a mold release agent, pigment, and curing catalyst is kneaded using a kneader, roll, or continuous mixer, and its excellent electrical properties, heat resistance, tracking resistance, etc. make it suitable for injection molding and transfer molding as electrical parts and automobile parts. and compression molding. On the other hand, unsaturated polyester resin molding materials that are solid at room temperature tend to be inferior in strength to other molding materials using unsaturated polyester resins such as SMC and BMC, so molded products that require strength It is considered unsuitable for thin-walled molded products, and because the molded product itself is brittle, it is a major cause of high defective rates, such as chipping and damage to the molded product during demolding, processing, or transportation. We are becoming one. [Object of the Invention] An object of the present invention is to provide a curable resin composition with excellent impact resistance that eliminates the drawbacks that are particularly apparent in molding materials that are solid at room temperature. [Summary of the Invention] The present invention was completed as a result of intensive research to achieve the above object. That is, a mixed resin component in which diallyl phthalate resin was blended in an unsaturated polyester resin at a ratio of 20 to 45 parts by weight based on 100 parts by weight of the unsaturated polyester resin, and 0.1 to 6% by weight based on the total amount of the composition was blended. A solid molding material characterized by having as essential components a butadiene acrylonitrile copolymer having an active vinyl group at the end and a copolymerizable vinyl monomer blended in an amount of 0.5 to 10% by weight based on the total amount of the composition. This is a curable resin composition for The composition of the present invention can be used as a molding material in a solid state at room temperature, greatly improving its strength, and making it possible to obtain a molding material with excellent storage stability. The following are used as the unsaturated polyester resin and diallyl phthalate resin that are the mixed resin component of the present invention. The unsaturated polyester resin is not particularly limited, and any unsaturated polyester that can be obtained by a conventional method using a conventional unsaturated dibasic acid, saturated dibasic acid, and polyhydric alcohol can be used. However, those that are solid at room temperature are preferable, and those with a softening point of 60 to 120°C are particularly preferable. Diallyl phthalate resin is a prepolymer of diallyl orthophthalate, and when a butadiene acrylonitrile copolymer having a vinyl terminal group is added to an unsaturated polyester resin, it can significantly improve impact strength, electrical properties, or moldability. This component is suitable for improving the properties of molding materials and maintaining the solid state of the molding material. The diallyl phthalate resin used may be one obtained by a conventional method, but it is blended at a ratio of 20 to 45 parts by weight to 100 parts by weight of the unsaturated polyester resin to form a mixed resin component. If it is less than 20 parts by weight, it is insufficient to impart moldability and mold release properties, and the solid state of the molding material cannot be maintained, and even if it is added in excess of 45 parts by weight, it is not economical. Further, as the copolymerizable vinyl monomer which is an essential component of the present invention, diallyl phthalate monomer and the like are more effective than highly volatile monomers such as styrene. In addition, butadiene acrylonitrile copolymer (hereinafter, this copolymer will be abbreviated as butadiene acrylonitrile) is another essential component of the present invention.
Only those having an active vinyl group at the end can be used. Butadiene acrylonitrile having an active vinyl group at the end can be used in combination with the above-mentioned copolymerizable vinyl monomer to enhance impact resistance. The butadiene acrylonitrile used in the present invention has an active vinyl group and therefore easily undergoes a crosslinking reaction in the presence of a radical initiator, making it more water resistant than when butadiene acrylonitrile without an active vinyl group is blended. There is very little deterioration in properties and chemical resistance. If the amount of butadiene acrylonitrile exceeds 6% by weight of the total amount, or if the amount of copolymerizable vinyl monomer exceeds 10% by weight of the total amount of the composition, the ester bond will not react. Therefore, it is undesirable because it causes a markedly poor appearance and a decrease in water resistance.
Furthermore, if the amount of butadiene acrylonitrile is less than 0.1% by weight and the amount of the copolymerizable monomer is less than 0.5% by weight based on the total amount of the composition, the effect of the present invention will not be achieved. The content is limited to 0.5-10% by weight. A curing catalyst is also used in the present invention, and any organic peroxide having a decomposition temperature of 110° C. or higher to obtain a half-life of 10 hours, such as dicumyl peroxide, can be used. As the filler, commonly used inorganic fillers such as calcium carbonate, aluminum hydroxide, and clay, and cellulose-based organic fillers such as pulp flock can be used. Glass fibers are generally used as reinforcing agents, and organic fibers can also be used. As the mold release agent, zinc stearate is widely used, but other higher fatty acids or their esters are also used. [Embodiments of the Invention] Examples of the present invention will be specifically described below. Example 1 2.1 moles of propylene glycol, isophthalic acid
From 0.8 mol and 1.2 mol of maleic anhydride, acid value 20 and softening point (by ring and ball method) 100℃
An unsaturated polyester resin (A) was obtained. Next, (A) unsaturated polyester resin 160g diallylphthalate prepolymer 65g acrylonitrile (acrylic vinyl group 3.8%)
Bound AN16.2%) diallyl phthalate monomer
20g Calcium carbonate 150g Aluminum hydroxide (H-42M Showa Light Metal)
450g zinc stearate 15g carbon black (#30 made by Mitsubishi Kasei) 5g dicumyl peroxide 5g were heated to 80℃ and kneaded in a double-arm kneader until the mixture became sufficiently homogeneous. To this, 120g of 6mm glass fiber chops were added. After kneading for 10 minutes, the mixture was taken out from the kneader and extruded and cut into pellets using an extruder to obtain a granular resin composition. Examples 2 to 3 A granular resin composition was obtained by carrying out the same operation as in Example 1 using the formulations shown in Table 1. Comparative Examples 1 to 3 Granular resin compositions were obtained by carrying out the same operation as in Example 1 using the formulations shown in Table 1.

[Table] The resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were molded using an injection molding machine under conditions of a mold temperature of 180°C, a pressure of 100 Kg/cm ² (gauge pressure), and a curing time of 60 seconds. Injection molding was performed to obtain a molded product. Characteristics of this molded article were obtained and are shown in Table 2.

【table】

〔Effect of the invention〕

As mentioned above, the curable resin composition of the present invention can significantly improve impact resistance by incorporating butadiene acrylonitrile having an active vinyl group at the end, and can also be molded into a thin wall.
There was no "chipping" phenomenon and the defective rate could be significantly reduced.

Claims (1)

[Claims] 1 A mixed resin component in which diallyl phthalate resin is blended in an unsaturated polyester resin at a ratio of 20 to 45 parts by weight based on 100 parts by weight of the unsaturated polyester resin, and a terminal blended in an amount of 0.1 to 6% by weight based on the total amount of the composition. butadiene acrylonitrile copolymer having an active vinyl group in the total amount of the composition.
A curable resin composition for a solid molding material, comprising as an essential component a copolymerizable vinyl monomer blended in an amount of 0.5 to 10% by weight.