JP3487669B2 - Unsaturated polyester resin composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unsaturated polyester resin composition used as a molding material, and more particularly to a molded article having excellent gloss. And a fast-curing unsaturated polyester resin composition. [0002] Conventionally, as a molding material of an unsaturated polyester resin, a sheet molding compound (S
MC) and bulk mold compound (BMC). SMC and BMC, for example, a filler, a curing agent, a release agent, a pigment,
A reinforcing or fibrous substance such as glass fiber is impregnated with a resin composition containing a thickener or the like to form a sheet or bulk. The above SMC and BMC are
It is mainly used in the compression molding method, and the obtained molded product is used in a wide range of fields such as housing equipment, industrial parts or automobile parts. [0003] Among the above uses, in the field of housing equipment such as bus units, there is a demand for high quality molded articles having both excellent appearance and excellent hot water resistance. Furthermore, in recent years, in order to increase the productivity of molded articles, the molding materials have also been required to have rapid curability. [0004] As a method for increasing the curing rate of an unsaturated polyester resin-based molding material, 2,5-dimethylhexane-2,5-diperoxybenzoate, t-butylperoxy-2-ethylhexanoate and t-butylperoxy-2-ethylhexanoate are known. There is known a method of shortening the curing time by using a curing catalyst composed of three components of butyl peroxyisopropyl carbonate to accelerate the initiation of the curing reaction (for example, US Pat. No. 4,278,558). However, when the curing speed of the SMC is increased, the curing on the SMC surface is started during the compression molding,
The SMC will harden while flowing. As a result, a flow pattern phenomenon occurs on the surface, a so-called pregelling phenomenon occurs, and the surface smoothness of the obtained molded article tends to be greatly impaired, and the gloss of the surface tends to be partially reduced. [0006] On the other hand, although not yet known, the present inventor has proposed a hydrogenated bisphenol-based unsaturated polyester resin having high reactivity and excellent hot water resistance among unsaturated polyester resins. By using this, it was possible to enhance the gloss of the surface and to obtain a molded product suitable for applications requiring hot water resistance, such as a bathtub. However, the hydrogenated bisphenol-based unsaturated polyester resin is more expensive than other unsaturated polyester resins, and thus has a problem that the cost of the obtained molded product is high. In addition, when a fast-curing curing agent as described above and the hydrogenated bisphenol-based unsaturated polyester resin having excellent reactivity are used in combination, the pregelling phenomenon is further promoted, and the appearance of a molded article is likely to be poor. I understand. An object of the present invention is not only to improve the productivity by shortening the molding time by increasing the curing speed, but also to improve the surface gloss and to reduce the appearance defect due to the pregelling phenomenon. An object of the present invention is to provide an unsaturated polyester resin composition that enables a molded article to be provided at low cost. SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and comprises (a) a hydrogenated bisphenol unsaturated polyester and (b) an iso unsaturated polyester. (C) a vinyl monomer, (d) a thermoplastic resin, (e) a first organic peroxide having a 10-hour half-life temperature of less than 50 ° C to 85 ° C, and (f) a 10-hour half-life. The first organic peroxide and the second organic peroxide, each containing a second organic peroxide having an initial temperature of 85 ° C. to 110 ° C., and having a relationship of a 10-hour half-life temperature of 10 ° C. or more. An unsaturated polyester resin composition containing an oxide. The (a) hydrogenated bisphenol-based unsaturated polyester used in the present invention is an unsaturated polyester using hydrogenated bisphenol as a glycol, for example, an unsaturated dicarboxylic acid such as maleic anhydride or fumaric acid, and isophthalic acid. It is synthesized by condensation using an acid and hydrogenated bisphenol A, and has been widely used as an unsaturated polyester for molding materials. The above-mentioned (b) iso-unsaturated polyester used in the present invention is also a conventionally widely used unsaturated polyester for molding materials, for example, an unsaturated dicarboxylic acid such as maleic anhydride or fumaric acid, and isophthalic acid. It is obtained by condensation synthesis using an acid and glycol such as neopentyl glycol, isopentyl glycol or propylene glycol. The vinyl monomer (c) used in the present invention is a monovinyl monomer which has been conventionally used as a diluent for unsaturated polyesters and thermoplastic resins in preparing unsaturated polyester resins. Examples of such vinyl monomers include suitable vinyl monomers such as styrene, acrylonitrile, acrylates, and methacrylates, and styrene is particularly preferably used. As the thermoplastic resin (d) used in the present invention, an appropriate thermoplastic resin conventionally used widely as a low shrinkage agent for unsaturated polyester resins can be used. Examples of thermoplastic resins that can be used include polystyrene, polyvinyl acetate, polymethyl methacrylate, polyethylene, saturated polyester, polyvinyl chloride polystyrene-acrylic acid copolymer, polystyrene-polyvinyl acetate copolymer, ethylene-vinyl acetate Copolymers, vinyl chloride-vinyl acetate copolymers, acrylonitrile-styrene copolymers and the like can be mentioned. The unsaturated polyester resin composition of the present invention contains the above-mentioned components (a) to (d) as a resin component. By blending these resin components in a specific ratio, the composition is more excellent. A molded article having a surface gloss can be provided. The preferred range of the mixing ratio of the resin component, that is, the specific ratio is (a) 5 to 25 parts by weight, more preferably 10 to 20 parts by weight of hydrogenated bisphenol-based unsaturated polyester, and (b) 20 to 40 parts by weight of a saturated polyester, more preferably 24 to 36 parts by weight, (c) 40 to 60 parts by weight of a vinyl monomer, more preferably 47 to 49 parts by weight, and (d) a thermoplastic resin 5 to 15 parts.
The amount is from 5 to 10 parts by weight, more preferably from 5 to 10 parts by weight. If the compounding ratio of the resin deviates from the above specific range, a molded article having excellent surface glossiness may not be obtained. The above (e) first organic peroxide has a 10-hour half-life temperature in the range of 50 ° C. to less than 85 ° C. As an example of such a first organic peroxide, ,
2,4-dichlorobenzoyl peroxide, o-methylbenzoyl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, t-butyl peroxide Vivalate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, di-t-butyl peroxyhexahydroterephthalate, t
-Butyl peroxyneohexanoate, t-hexylperoxybivalate, octanoyl peroxide,
Decanoyl peroxide, cumyl peroxy octoate, succinic acid peroxide, acetyl peroxide, m-trioil peroxide, t-amyl peroxy-2-ethylhexanoate, t-amyl peroxy bivalate, and the like. be able to. In the present invention, one or more of these organic peroxides are used as (e) the first organic peroxide. The (f) second organic peroxide used in the present invention is an organic peroxide having a 10-hour half-life temperature in the range of 85 ° C. to 110 ° C. Examples of such organic peroxides include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, methyl cyclohexanone peroxide, tris-t-butylperoxytriazine, 1,1-di-t-butyl peroxide. Oxy-3,5-
Trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, 2,2-di-t-butylperoxybutane, di-t-butylperoxyazelaate, t-butylperoxy-3,3 5-trimethylhexanoate, t-butyl peroxyacetate, t-
Butylperoxybenzoate, t-butylperoxyisopropyl carbonate, t-butylperoxymaleic acid, t-butylperoxylaurate, t-butylperoxyallylcarbonate, 2,5-dimethyl-
Examples thereof include 2,5-dibenzoylperoxyhexane, 2,2-di-t-butylperoxyoctane, peroxyhexane, and di-t-butylperoxyisophthalate. As the second organic peroxide, one or more of these organic peroxides are used. In the present invention, at least one of the first and second organic peroxides is used as described above.
It is necessary that the first and second organic peroxides having a time half-life temperature difference of 10 ° C. or more are contained.
That is, in the unsaturated polyester resin composition of the present invention, each of the first and second organic peroxides is used alone or in combination of two or more.
It is necessary that at least one set of the first and second organic peroxides having a relationship of 0 ° C. or higher is contained. Thus, 1
By including the first and second organic peroxides having a difference of 0 hour half-life temperature of 10 ° C. or more, quick curability is enhanced. The total amount of the first and second organic peroxides is usually 1 to 100 parts by weight based on 100 parts by weight of the total weight of the resin components (a) to (d). It is in the range of 5 parts by weight, preferably 1.5 to 2.5 parts by weight. First
If the amount of the second organic peroxide is small, the curing reaction will be slow, and a long time will be required for molding. On the other hand, when the addition amount of the first and second organic peroxides is too large,
The curing reaction starts before the mold is closed by the compression molding machine, and the pre-gelling phenomenon occurs on the molding material surface (the curing reaction starts earlier than necessary on the molding surface and the molding surface does not become smooth) , The appearance of the molded product deteriorates,
The gloss will be reduced. Further, (e) a first organic peroxide and (f)
The ratio of the second organic peroxide is 1: 1 to 1 by weight.
It is preferred that the ratio be in the range of 4 to 1, more preferably
1.5: 1 to 2.5: 1. This is (e) the first
If the proportion of the organic peroxide is small, the initiation of the curing reaction is delayed, and (f) the proportion of the second organic peroxide is large, so that the pregelling phenomenon is liable to occur.
(F) If the proportion of the second organic peroxide is small, the curing is difficult to complete, and the residual styrene increases, so that the strength of the obtained molded article decreases. In the unsaturated polyester resin composition of the present invention, in addition to the hydrogenated bisphenol-based unsaturated polyester, iso-unsaturated polyester, vinyl monomer, thermoplastic resin, and first and second organic peroxides, Other optional components such as a filler, a fiber reinforcing material, a chemical thickener, a release agent, a stabilizer, and a coloring agent can be added as long as the object of the present invention can be achieved. As the above-mentioned filler, there can be used an appropriate filler conventionally used as a filler for molding materials such as calcium carbonate, talc, silica, clay, asbestos, glass powder and aluminum hydroxide. Further, as the above-mentioned fiber reinforcing material, for example, glass fiber can be mentioned. For example, glass fiber having a diameter of 8 to 50 μm and a length of about 5 to 150 mm can be used. Examples of the chemical thickener include magnesium oxide and magnesium hydroxide, and examples of the release agent include zinc stearate and calcium stearate, and examples of the stabilizer include hydroquinone and parabenzoquinone.
As the coloring agent, for example, titanium dioxide, carbon black, phthalocyanine blue, red iron oxide and the like are used. The unsaturated polyester resin composition of the present invention is prepared by mixing and kneading the above-mentioned essential components (a) to (f) and the above-mentioned optional components except for the fiber reinforcing material, and using a conventional means device. SMC or BMC can be obtained by impregnating the fiber reinforcement. The glass fiber as the fiber reinforcing material is usually blended so as to account for approximately 10 to 40% by weight based on the total amount of the composition. When the blending ratio of the glass fiber is small, it is difficult for the molded article to exhibit sufficient strength.
Conversely, if the amount of the glass fiber is too large, the resin is not sufficiently impregnated into the glass, cracks are easily generated in the obtained molded product, and the glass is exposed on the surface of the molded product, and the appearance is deteriorated. Let it. The SMC or BMC from which the unsaturated polyester resin composition of the present invention is obtained is preferably used in a hot press molding method, whereby a bathtub, a waterproof pan, a unit bath (so-called bathtub and washing area are integrally formed) A molded product) is obtained. The unsaturated polyester resin composition of the present invention can be obtained by using the above-mentioned SMC or BMC as a raw material.
Not only can it be used for producing RP molded products, but it can also be used for producing FRP molded products by other molding methods. Using the unsaturated polyester resin composition of the present invention, for example, at 110.degree.
When molded at ° C., the organic peroxide in the composition decomposes at a rate corresponding to the heating temperature to generate radicals. In this case, the temperature, the radical concentration, and the concentration of the unsaturated double bond in the resin composition determine the rate of the polymerization reaction. In the present invention, the 10-hour half-life temperature is 50 ° C.
(E) The polymerization reaction rises due to radicals generated by the first organic peroxide which is lower than 85 ° C. Due to the heat generated by the polymerization, the decomposition of the organic peroxide further proceeds, the polymerization reaction proceeds, and the temperature of the resin increases. As a result, the decomposition of (f) the second organic peroxide having a 10-hour half-life temperature of 85 ° C. to 110 ° C. proceeds rapidly, and the polymerization reaction proceeds more quickly and is achieved in a short time. Will be. On the other hand, the type and amount of the unsaturated polyester affect the appearance of the molded article which has been rapidly cured by the above series of polymerization reactions. In other words, when a highly reactive hydrogenated bisphenol-based unsaturated polyester is frequently used, the polymerization reaction in the above-mentioned fast-curing polymerization reaction becomes too fast. Therefore, the polymerization reaction proceeds considerably during the molding due to the depression of the press, and the above-mentioned pregelling phenomenon tends to occur. That is, a flow pattern that reduces the gloss of the appearance appears on the surface. In order to suppress such a phenomenon, in the present invention, a mildly reactive iso-unsaturated polyester is used in combination, whereby the polymerization reaction occurs after the completion of press descent, and as a result, a molding having excellent appearance is obtained. Goods can be obtained. The present invention will be described below by describing non-limiting examples and comparative examples of the present invention. In addition,
In the following, “parts” means “parts by weight” unless otherwise specified. Examples 1 and 2 (a) Hydrogenated bisphenol-based unsaturated polyester (condensation reactant of maleic anhydride / hydrogenated bisphenol A / propylene glycol = 44/32/24 (weight ratio)) Neopentyl glycol unsaturated polyester (maleic anhydride / isophthalic acid / neopentyl glycol / propylene glycol = 32/23/34 /
(C) styrene monomer (d) polystyrene The above resin components (a), (b) and (d)
Was added to the (c) styrene monomer in the proportions shown in Table 1 below, respectively, to make the total 100 parts. Next, based on a total of 100 parts of the resin components (a) to (d), 135 parts of calcium carbonate as a filler, 5 parts of zinc stearate as a release agent, 7 parts of titanium oxide as a pigment, and an inhibitor Parabenzoquinone (PBQ)
03 parts were added and mixed. The resulting mixture was mixed with t-butylperoxy-2-ethylhexanoate having a 10-hour half-life temperature of 74 ° C. as a first organic peroxide (e) in the proportions shown in Table 1. And t-butyl peroxybenzoate (hereinafter abbreviated as TBPB) having a 10-hour half-life temperature of 105 ° C. as a second organic peroxide (f), and mixing and further adding magnesium oxide as a thickener. (MgO) 1.
0 parts were added and mixed, and the mixture was 25.4 mm in length × 1 in diameter.
83 parts of 3 μm glass fibers were impregnated and covered with a polyethylene film to obtain SMC. SMC obtained in this way
Was aged at 40 ° C. for about 1 day. Using the SMC obtained as described above, 30
A miniature bath (bottom thickness: about 7.5 mm) 1 shown in FIG. 1 was press-formed using a 0-ton press. At the time of molding, the upper mold was set at a temperature of 150 ° C. and the lower mold was set at a temperature of 135 ° C., and 5.4 kg of SMC obtained as described above was charged.
Pressure molding was performed at a speed of about 3 mm / sec. The obtained molded product was taken out of the mold and evaluated in the following manner. That is, the minimum required pressure-holding time for preventing blistering due to uncuring on the bottom surface of the molded product was measured. Further, as an appearance evaluation of the molded article, a 60-degree specular glossiness of the molded article (measurement was performed in accordance with JIS-Z-8741) was measured. Furthermore, the presence or absence of a rough feeling based on the pre-gel phenomenon on the molded product surface was visually evaluated. The results of the above evaluations are also shown in Table 1. Comparative Examples 1-4 As shown in Table 2 below, unsaturated polyester (a)
At least one of the unsaturated polyester (b) and the ortho-unsaturated polyester (b '), (c) a styrene monomer, and (d) polystyrene are blended, and the total is 100
Department. Next, with respect to 100 parts of the above resin, Example 1
In the same manner as described above, a filler, a release agent, a pigment and an inhibitor were mixed. As shown in Table 2, the resulting mixture was used as a first organic peroxide (e), t-butylperoxy-2-ethylhexanoate having a 10-hour half-life temperature of 74 ° C. And TBPB having a 10-hour half-life temperature of 105 ° C. as a second organic peroxide (f) or t-butyl peroxyisopropyl carbonate having a 10-hour half-life temperature of 97 ° C. as in Comparative Example 2 After mixing, 1.0 part of magnesium oxide as a thickener was added and mixed, and an SMC was obtained in the same manner as in Example 1 using the obtained mixture. Further, using the obtained SMC, pressure molding was performed in the same manner as in Example 1 to obtain a molded product. The obtained molded product was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2 below. [Table 1] [Table 2] As is clear from Evaluation Table 2 of Examples and Comparative Examples , in Comparative Examples 1 and 2, the second organic peroxide (f) was small or the 10-hour half-life temperature was within 10 ° C. This is because only two kinds of the first and second organic peroxides having the relationship of (1) were used, and the required packing pressure was extremely long at 340 to 360 seconds. As for the gloss, the iso-unsaturated polyester (b)
In Comparative Example 1 in which was used alone, the glossiness was as low as 80 degrees. In Comparative Example 3, since the first and second organic peroxides each having a 10-hour half-life temperature of 10 ° C. or more are used, the required holding time for molding is reduced to 100 seconds. Although the glossiness of the surface is as high as 85 because of the use of hydrogenated bisphenol-based unsaturated polyester alone, it causes a pregelling phenomenon during compression molding, resulting in poor appearance of the molded product, and it is used as a product. I could not get it. Further, in Comparative Example 4, since the ortho-unsaturated polyester was used and the first organic peroxide was used alone in a large amount, the required pressure-holding time for molding was relatively short at 150 seconds. The appearance of the molded product was also poor. On the other hand, in Examples 1 and 2, since the first and second organic peroxides were blended as described above, the required packing pressure was 120 seconds to 180 seconds. It can be seen that the time is reduced to about て as compared with 1 and 2. Furthermore, the 60-degree specular gloss of the surface was as high as 85 to 90, and the pregelling phenomenon did not occur. Therefore, it was possible to obtain a high-quality molded product having a good appearance. As described above, according to the present invention, the first,
Since the second organic peroxide is contained, the curing proceeds rapidly, and further, the polymerization reaction proceeds rapidly due to the reactivity of the hydrogenated bisphenol-based unsaturated polyester resin, and the polymerization reaction proceeds with the iso-unsaturated polyester resin. Progresses gently. Therefore, a molded product can be obtained with high productivity without requiring a long time until final curing, and a flow pattern due to a pregelling phenomenon is unlikely to occur on the surface, and a high-quality surface with good gloss is obtained. Can be provided. Moreover, the amount of the relatively expensive hydrogenated bisphenol-based unsaturated polyester can be reduced by the use of the relatively inexpensive iso-unsaturated polyester, and the curing speed is increased as described above. Therefore, it is possible to provide a high-quality molded product as described above at low cost and with high productivity.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a miniature bath molded product molded in order to evaluate the appearance of the molded product in an embodiment. [Explanation of reference numerals] 1. Molded product

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Claims (1)

(57) [Claims] [Claim 1] Hydrogenated bisphenol-based unsaturated polyester, iso-unsaturated polyester, vinyl monomer, thermoplastic resin, and a 10-hour half-life temperature of 50 ° C. At least one first organic peroxide having a temperature of less than 85 ° C. and at least one having a 10-hour half-life temperature of 85 ° C. to 110 ° C.
A second organic peroxide, and a first organic peroxide and a second organic peroxide having a 10-hour half-life temperature difference of 10 ° C. or more. An unsaturated polyester resin composition, characterized in that: