JPS59207945A - Curable resin composition - Google Patents

Abstract

PURPOSE:The titled composition useful for small-sized boats, bathtubs, various kinds of electric parts, and tanks, having improved strength and modulus of elasticity free from poor molding such as poor impregnation, poor deaeration, poor packing, etc., consisting of a thermosetting resin and specific mica flakes. CONSTITUTION:The desired composition obtained by blending a thermosetting resin (preferably unsaturated polyester resin) with 0.03-3 times as much mica flakes having <=2,000mum particle diameter, <=10 aspect ratio, and >=0.76 average shape coefficient (preferably >=0.78) (designated by 4piB/l<2> where S is area of flake of projection chart seen from above and l is length of periphery of it) and <=20 flakes (preferably <=15) with <=0.70 shape coefficient among 100mica flakes as the thermosetting resin. Preferably addition of fiber reinforcing material (e.g., glass fiber, etc.) to the mica flakes provides high impact resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a curable resin composition useful for producing molded articles having high strength and high modulus of elasticity.

It is well known that mica flakes are used to strengthen plastics to obtain molded products with high elasticity, heat resistance, chemical resistance, electrical insulation, barrier properties, etc. Furthermore, there is also a method of improving strength and impact resistance by using fibrous reinforcing materials together.
well known.

These methods are used both when the resin is a thermosetting resin and when the resin is a thermoplastic resin.

However, when mica flakes or mica flakes and fibrous reinforcing materials are blended into a thermosetting resin, the viscosity of the mixture increases significantly, fluidity decreases, and impregnation, defoaming, and filling occur. It is very difficult to obtain a molded product with the desired characteristics because it causes troubles such as defects and molding defects. Attempts to improve this point have been made, for example, by tri-blending powdered unsaturated Borienether with mica flakes to avoid the above-mentioned troubles, or by sandwiching mica flakes between fibrous reinforcing materials to form composite reinforcements in advance. By impregnating this with resin, troubles during mixing can be prevented, and molded products with excellent strength, elastic modulus, and impact resistance can be obtained by taking advantage of the respective characteristics of fibrous reinforcement and mica. Several methods have been proposed. However, in the first method of tri-blending unsaturated polyester with mica flakes, the powdered polyester resin is extremely special and is difficult to obtain.
Furthermore, molding of tri-blended powder is difficult, except for flat shapes, and it has not been put into practical use. A second method in which composite reinforcement is formed in advance is when forming a p-FRP molded product using a molding method such as a hand lay-up method, preform mated die method, cold press method, or continuous panel method. , is useful when used as a reinforcing material for prepreg, but spray-up method, premix molding method, S
In the case of MC molding method and SMC molding method, turning lamps are applied.

The present inventors conducted various studies on the viscosity behavior of a thermosetting resin liquid and mica flakes, or a mixture of a thermosetting resin liquid, mica flakes, and fibrous reinforcing material, and as a result, the shape factor of mica flakes and mica flakes were determined. There is a close relationship between the viscosity of a curable resin mixture containing
．． When using mica flakes of 76 or higher, the viscosity of the mixture decreases and the fluidity improves, resulting in poor impregnation, poor defoaming, and
The present invention was achieved by discovering that molding defects such as filling defects can be eliminated.

That is, the present invention uses a thermosetting resin and a shape factor of 0.7.
This is a curable resin composition consisting of 6 or more mica flakes. In the present invention, the shape factor is defined as the ratio of the value obtained by multiplying plane 1 (13) of the projection view of the mica flake from above by 4π and the square of the length of the head <1>, that is, 4πB/12. For example, 1 for a circle, 0.785 for a square,
For an equilateral triangle, it is 0.605.

The area and radius of the mica flake projection can be determined by the following method. First, a scanning electron micrograph of mica ferrite is taken as a projection diagram. Next, the area of the director and the area surrounded by the director is measured using a sensor along the image of the projection map. Figures 1 and 2 are scanning electron micrographs (190x magnification) of mica flakes.

The shape factor of each mica flake was calculated from the area and radius measured by this method, and as shown in Figure 6,
Draw the cumulative frequency curve of the shape factor. The point at which the cumulative number of flakes reaches half of the measured number, that is, the shape coefficient of the average value, is taken as the shape coefficient of that mica flake. The number of particles to be measured is desirably 300 or more in order to improve accuracy. In order for the measurement sample to reflect the original sample as faithfully as possible, it is preferable to perform accurate reduction using a rotary divider or the like.

The resin composition of the present invention has a particle size of 2,000 μl or less,
It is obtained by blending mica flakes with an aspect ratio of 10 or more and an average shape factor of 0.76 or more (preferably 0.78 or more) into a thermosetting resin. In addition, the mica flakes 10
It is desirable that the number of shapes having a shape factor of 0.70 or less out of 0 is 20 or less (preferably 15 or less).

Usually, mica is crushed using a crushing method that applies strong impact energy to the mica, such as in a jet mill type crusher, but the shape of mica flakes obtained by such a conventional crushing method is shown in Figure 2. As mentioned above, the shape is very irregular, and therefore only a shape factor having an average value of about 0.65 to 0.76 can be obtained.

However, in the present invention, since the mica is crushed with weak impact energy and is crushed with a fine micron type crusher to smooth out sharp edges, the shape factor is 0.76 or more as shown in Fig. 1. You can get things. The mica flakes used in the present invention can be efficiently obtained with a shape factor of 0.76 or more by using the above-mentioned fine micron type pulverizer, but it is limited to the use of the above-mentioned pulverizer. Any grinding method that produces mica flakes having the specific shape described above may be used.

Examples of thermosetting resins used in the present invention include saturated polyester resins, unsaturated polyester resins, vinyl ester resins, epoxy resins, and phenol resins.

Among these, unsaturated polyester resins are preferably used.

The mica flakes used in the present invention include flakes of muscovite, phlogopite, biotite, synthetic mica, and the like. In carrying out the present invention, a known surface treatment such as silane treatment may be carried out in order to increase the affinity of the interface between the mica flakes and the resin.

Furthermore, in the present invention, when a high degree of impact resistance is required in addition to a high modulus of elasticity, it is preferable to use a fibrous reinforcing material in addition to mica flakes. Glass fiber, carbon fiber, metal fiber, vinylon,
Examples include organic fibers such as polyester, and natural inorganic fibers such as asbestos and barium titanate. These fibers may be used alone or in combination of two or more types, and may be subjected to surface treatment such as silane treatment in order to improve affinity with resin. In carrying out the present invention, various reinforcing materials and fillers such as insulator, talc, calcium carbonate, and wallanutonite may be used, and further known additives such as colorants, lubricants, stabilizers, plasticizers, and antistatic agents may be used. There is nothing wrong with adding things.

Further, in the present invention, the mica flakes are preferably used in an amount of 0603 to 3 times the weight of the thermosetting resin. If the amount of mica flakes is less than 0.03 times by weight, the effect of the present invention will be low, and if it is more than 3 times by weight, moldability will become difficult.

The amount of fibrous reinforcing material to be used varies significantly depending on the molding method and cannot be generally specified.
It is usually used in an amount of 0.03 to 10 times the weight of the thermosetting resin.

To mold a molded article from a composition consisting of mica flakes and resin or mica flakes, fibrous reinforcing material, and resin, there are methods such as hand lay-up method, spray-up method, preform matte die method, cold plane method, continuous panel method, SMC.
A molding method, a premix molding method, a BMC molding method, etc. are used. Additionally, a molding method using prepreg is also used. Using this molding method, the shape factor can be reduced to an average value of 0.7.
When molding a curable resin composition using mica flakes of 6 or more as a reinforcing material, the viscosity of the composition does not increase significantly, and defoaming during molding is also good, resulting in poor impregnation, poor filling, etc. A molded product having desired physical properties can be obtained without causing any molding defects. Furthermore, as an effect of the present invention,
When mica flakes with such a specific shape are used, there is almost no damage to the mica flakes even when using a molding method that thoroughly kneads after thickening, such as premix molding, BMC molding, SMC molding, etc. There are many things that can be mentioned. For this reason, molded products with extremely excellent performance can be obtained.

The resin composition according to the present invention can be molded into any shape that thermosetting resins are currently molded into, and can be applied to structural parts, small ships, vanutaps, various electrical parts, automobile-related parts, tanks, and various other uses. It is possible.

The present invention will be specifically explained below using examples, but the present invention is not limited thereto.

Unless otherwise specified, parts refer to parts by weight.

Example 1 Phlogopite was pulverized using a fine micron type pulverizer (manufactured by Hosokawa Micron Co., Ltd.), and the fine powder portion was reduced to 10% by air classification.
After cutting, phlogopite flakes having an average flake diameter of 401 parts m, a shape factor of 0.80, and an aspect ratio of 60 were obtained (FIG. 1). Moreover, out of 100 mica flakes, there were 7 flakes with a shape factor of 0.70 or less. The shape factor of mica was determined by measuring the area and thickness of a scanning electron micrograph of mica using image analysis Sinute J (MOP-Modular System, manufactured by Anglo-French Seiki Sangyo Co., Ltd.). The cumulative frequency curve of these shape factors is shown in FIG.

The resin solution is cast onto a polyethylene film, the mica flakes are sprinkled on top of the film, and the polyethylene film on which the resin solution is cast is pressed onto the film, and the mica flakes are impregnated with the resin solution to increase the viscosity. It was made into SMC. As the resin liquid, 100 parts of unsaturated polyester resin (Revolac 2053, Showa Kobunshi Co., Ltd. i), 1 part of anine stearate, and tertiary butyl peroxide (hereinafter referred to as TB!:'
) 1.5 parts, rosebenzoquinone (hereinafter referred to as PBQ)
) and 1.5 parts of magnesium oxide were mixed together.

The amount of mica flakes was 60% by weight in the composition. This SMC was press-molded at 130° C. for 15 minutes and post-cured at 100° C. for 2 hours to form a flat plate with a thickness of 5 mm. The physical properties of this flat plate were measured. The results are shown in Table 1. In addition, the bending performance is ASTMu4D790,
Izot impact strength was measured with a notch according to ASTM D256.

Comparative Example 1 After pulverizing phlogopite with a jet mill, it was air classified, and the average flake diameter was 591 tm, the aspect ratio was 29, and the shape factor was 0.
．． 70, shape factor 0 contained in 100 mica flakes
．． Mica flakes with a number of mica flakes of 70 or less were obtained. The test was carried out in the same manner as in Example 1 except that the mica flakes and the thermosetting resin used in Example 1 were used. In this test, it was extremely difficult to impregnate the mica flakes with the resin liquid. The physical property measurement results are shown in Table 1, and the effects of the present invention are clear from the results of Example 1 and Comparative Example 1.

Example 2 BMC was manufactured using a double-arm kneader. As the resin liquid, unsaturated polyester resin (Rivolac 2053,
(manufactured by Showa Kobunshi Co., Ltd.) 100 parts, anine stearate 1
parts, naphthenic acid coba 71zl-0,1 parts, TBPl, 5
1 part, 0.4 parts of PBQ O, and 3 parts of Myo were mixed and used.

Mica flakes are obtained by crushing muscovite in the same manner as in Example 1.
Average particle size obtained by classification: 14 ltm, shape factor: 0.8
1, an aspect ratio of 22, and 5 mica flakes with a shape factor of 0.70 or less contained in 100 mica flakes were used. Glass fibers (1A' chopped strands) were also used, and the ratio of resin liquid, mica flakes and glass fibers was 35:5[];15 by weight. The stirring rotation speed of the double-arm kneader was 651”pm, and the stirring time was 1
It was set to 0 minutes. The obtained BMC was pressed into a flat plate, cured at 130°C for 15 minutes, and then post-cured at 100'°C for 2 hours to obtain a sample for strength measurement. In addition, the molded product was burned in an electric furnace, mica flakes were recovered, and their average particle size and aspect ratio were measured. Table 1 shows the physical properties of the molded product and the recovered mica.

Comparative Example 2 White mica was ground as mica flakes using a jet mill,
The average particle diameter obtained by classification is 15 μm, the shape factor is 0.74, the aspect ratio is 23, and the number of mica flakes with a shape factor of 0.74 or less contained in 100 mica flakes is 3.
The test was conducted in the same manner as in Example 2 except that five mica flakes were used. In addition, the molded material was collected and its average particle size and aspect ratio were measured. The results are shown in Table 1. In this experiment, the impregnating properties were poor, and the mica flakes were severely damaged when mixed in the kneader, resulting in a significant decrease in physical properties.

Example 3 A laminate was formed by a hand lay-up method.

Phlogopite as mica? : Average particle size 3D O)tm, aspect ratio 70, average shape factor 0.79, mica flakes obtained by crushing and classifying in the same manner as in Example 1, 10
Mica flakes in which the number of mica flakes having a shape factor of 0.70 or less was 10 were used. As the resin liquid, unsaturated polyester resin (Yupica 2035P, Japan Upica G)
100 parts, methyl ethyl ketone peroxide 0.
A 9 part mixture was used. The mica flakes and the resin liquid were thoroughly mixed in a weight ratio of 20:80 to obtain a mixed liquid having a viscosity of 9.5 voids. A glass chopped strand mat (M-600, manufactured by Asahi Fiberglass) was impregnated with the mixed solution to obtain a mixture in which the ratio of resin solution, mica flakes, and glass fibers was 60:15:25 by weight. Since the viscosity of the liquid mixture was low, the impregnating properties were good.After laminating three layers in a semi-cured state, they were cured at room temperature for 1 night, and then post-cured at 80°C for 4 hours, resulting in a thickness of 4. An unsaturated polyester laminate of 8 mm containing 25% by weight of glass fibers and 15% by weight of mica flakes was produced.The performance measurements are shown in Table 1.

Comparative Example 6 A laminate was produced in the same manner as in Example 3 except that Mesolite 6O-8 (sold by Kuraray Co., Ltd.) was used as mica flakes. The average flake diameter of mica flakes is 280 l
tm, aspect ratio 75, shape factor 0.68, and the number of mica flakes with a shape factor of 0.70 or less contained in 100 mica flakes was 52. Mica flakes 20% by weight
, the viscosity increases when 80% by weight of resin liquid is mixed, and 4
Reached 5 voices. Even when impregnating a mat, the impregnating property was very poor. A laminate was produced in the same manner as in Example 3,
Its physical properties were measured and listed in Table 1. The effects of the present invention are clear from the results of Example 6 and Comparative Example B.

Example 4 A prepreg consisting of mica flakes, glass cloth and epoxy resin was produced. The mica flakes were obtained by crushing phlogopite with a particle diameter of 220/1 m and an anuvect ratio of 70.
, mica flakes with a shape coefficient of 0.78 and 15 particles having a shape coefficient of 1i0.70 or less out of 100 mica flakes were used. As the resin liquid, epoxy resin (Epicoat 828
, shell chemistry) 100 parts, 1 methyl ethyl ketone
00 parts, 20 parts of 3.3'diaminodiphenyl sulfone,
Boron trifluoride monoethylamine complex salt (B-Jun-400,
A mixed solution consisting of 1 part (Hashimoto Chemical Industry) was used. Mica flakes and resin liquid by weight,! A 200 g/m2 glass cloth (WE-1
After impregnating with 8K-104BZ-2 (Nitto Dokyen), it was squeezed with a roller and dried to volatilize the methyl ethyl ketone to form a prepreg with a mica flake:resin glass cloth weight ratio of 20.30°50. Obtained. The prepreg was laminated in four layers and heated at 160° C. for 20 minutes, and then immediately pre-nulled at 160° C. and a pressure of 5 Kg/cyn2 for 60 minutes. Post-cure at 180℃ for 2 hours to a thickness of 1.8mm.
An epoxy laminate was obtained. Its performance was measured and the results are shown in Table 1.

Comparative Example 4 Phlogopite was ground as mica flakes using a roller mill, with an average flake diameter of 230 μm, an aspect ratio of 65, an average shape factor of 0.68, and a shape factor of 0.70 or less contained in 100 mica flakes. A υ laminate was obtained in the same manner as in Example 4, except that mica flakes having 56 pieces were used. The results of measuring the physical properties are shown in Table 1. From the results of Example 4 and Comparative Example 4, the effects of the present invention are clear.

Comparative Example 5 Using the same resin liquid and glass cloth as in Example 4, a prepreg with a resin to glass cloth ratio of 50 resin and 50 glass cloth by weight was obtained. A laminate was obtained in the same manner as in Example 4, and its physical properties were measured. The results are shown in Table 1. From Example 4 and Comparative Example 5, it is clear that the addition of mica flakes significantly improves the elastic modulus in particular.

Margin below

[Brief explanation of the drawing]

Figure 1 shows that the average value of the shape factor used in Example 1 is 0.8.
This is a scanning electron micrograph of mica flakes of No.
The figure is a scanning electron micrograph of mica flakes used in Comparative Example 1 and having an average shape factor of 0.70. Figure 3 shows
1 is a cumulative frequency curve of mica flakes used in Example 1 and Comparative Example 1, 1 is a cumulative frequency curve of mica flakes used in Example 1, and 2 is a cumulative frequency curve of mica flakes used in Comparative Example 1. Patent Applicant RiRa Co., Ltd. Representative Patent Attorney Ken Honda Figure 1 Figure 2

Claims (1)

[Scope of Claims] (1) A curable resin composition comprising a thermosetting resin and mica flakes having an average shape factor of 0.76 or more. (2) The mica flakes are 0.0% relative to the thermosetting resin.
The curable resin composition according to claim (1), which contains 6 to 6 times a double image. (6) Out of 100 mica flakes, the shape factor is 0070
The curable resin composition according to claim (1) or (2), wherein the proportion of the following mica flakes is 20 or less. (4) The curable resin composition according to claim (1), (2) or (3), further comprising a fibrous reinforcing phase.