JP2003201395A - Unsaturated polyester resin molding material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an unsaturated polyester resin molding material which gives moldings having improved mechanical properties by imparting impact resistance without damaging excellent original electric properties and heat resistance of the conventional one. <P>SOLUTION: The unsaturated polyester resin molding material comprises (a) an unsaturated polyester resin, (b) an inorganic base material, and (c) a thermoplastic polyurethane resin as the essential components, and preferably the unsaturated polyester resin molding material comprises, on the basis of the entire molding material, (a) 15-30 wt.% unsaturated polyester, (b) 50-70 wt.% inorganic base material and, simultaneously, (c) 5-25 pts.wt., based on 100 pts.wt. unsaturated polyester resin (a), thermoplastic polyurethane resin. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an unsaturated polyester resin molding material.

[0002]

2. Description of the Related Art Unsaturated polyester resins are superior to phenolic resins, epoxy resins, etc. in electrical characteristics such as dielectric breakdown strength, insulation resistance, tracking resistance, arc resistance, etc. It has been widely used for insulating parts such as automobile electrical parts. In addition to its excellent mechanical strength, heat resistance and chemical resistance, it is used in a wide variety of applications such as cosmetic plates, buttons, corrugated flat plates for molded products, and septic tanks.

Unsaturated polyester resins, like other thermosetting resins, have hardened and brittle properties. Therefore, unsaturated polyester resin molding materials have conventionally been blended with organic base materials such as pulp and inorganic base materials such as glass fibers mainly for the purpose of improving mechanical properties such as impact resistance and bending strength. There is. However, as electric and electronic devices have become smaller and thinner in recent years, cracking and chipping in thin parts of molded products have become a problem, and demands for improving the mechanical properties of parts have become stricter. With respect to this problem, heat resistance and electrical properties are often deteriorated only by improving the mechanical properties by blending the above-mentioned base material, and the effect is not sufficient. Therefore, it is required to impart impact resistance to the unsaturated polyester resin molding material and improve mechanical characteristics while maintaining the electrical characteristics and heat resistance that have been conventionally possessed.

[0004]

The present invention provides mechanical properties by imparting impact resistance without impairing the excellent electrical properties and heat resistance of the conventional unsaturated polyester resin molding materials. An improved unsaturated polyester resin molding material is provided.

[0005]

These objects are achieved by the present invention described in (1) to (3) below. (1) An unsaturated polyester resin molding material comprising an unsaturated polyester resin (a), an inorganic base material (b), and a thermoplastic polyurethane resin (c) as essential components. (2) The unsaturated polyester resin (a) is contained in an amount of 15 to 30% by weight, the inorganic base material (b) is included in an amount of 50 to 70% by weight, and the unsaturated polyester resin (a) 1 is included in the entire molding material.
5 parts by weight of thermoplastic polyurethane resin (c) 5
The unsaturated polyester resin molding material according to (1) above, containing 25 to 25 parts by weight. (3) The thermoplastic polyurethane resin (c) has an average particle size of 1
The unsaturated polyester resin molding material according to the above (1) or (2), which has a spherical shape of 0 to 150 μm.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to an unsaturated polyester resin molding material (hereinafter simply referred to as "molding material"). The molding material of the present invention contains an unsaturated polyester resin (a), an inorganic base material (b), and a thermoplastic polyurethane resin (c) as essential components, and preferably the thermoplastic polyurethane resin has a fine powder spherical shape. It is a thing.
Hereinafter, the molding material of the present invention will be described in detail.

The unsaturated polyester resin (a) used in the molding material of the present invention is not particularly limited, but includes ortho-type, iso-type and para-type resins, and also includes prepolymers thereof. These can be used alone or in combination of two or more. Among these, it is preferable to use the isotype or paratype. This makes it possible to impart heat resistance and electrical characteristics to the molded product. Further, it is particularly preferable to use the para type. Thereby, higher heat resistance can be imparted. The properties of the unsaturated polyester resin are not particularly limited, but those having a softening point of 80 to 100 ° C are preferable. The unsaturated polyester resin having such properties is suitable for use in the present molding material because of its viscosity characteristics and the like, and a molding material having excellent electrical characteristics and moldability of a molded product can be produced.

An inorganic base material (b) is added to the molding material of the present invention in order to impart mechanical properties and flame retardancy to the molded product. The inorganic substrate used in the present invention is not particularly limited, for example, glass fiber, calcium carbonate, clay,
Examples thereof include silica and magnesium oxide. If necessary, a flame-retardant inorganic base material such as aluminum hydroxide or zinc borate may be used in combination. Among these, the use of glass fiber is preferable because the mechanical strength can be improved while maintaining the heat resistance.

The blending amount of the unsaturated polyester resin and the inorganic base material is not particularly limited, but the unsaturated polyester resin is 15 to 30% by weight, and the inorganic base material 50 is based on the whole molding material.
Is preferably 70 to 70% by weight, more preferably 20 to 30% by weight of unsaturated polyester resin, and the inorganic base material 6
It is 0 to 70% by weight. By making both the compounding amounts within such a range, the workability of forming a molding material and the moldability of a molded article can be improved, and the electrical characteristics and mechanical characteristics of the molded article can be improved. When the unsaturated polyester resin is less than the lower limit value or the inorganic base material is more than the upper limit value, it becomes difficult to form a molding material or the moldability is deteriorated, so that the electrical characteristics and mechanical properties of the molded product are reduced. It may affect the characteristics. On the other hand, when the unsaturated polyester resin is more than the upper limit value or the inorganic base material is less than the lower limit value, the material viscosity at the time of manufacturing a molding material is lowered and it becomes difficult to form a molding material, or the inorganic base material is blended. The effect may not be sufficient.

When glass fibers are used as the inorganic base material to improve the mechanical properties of the molded product, it is preferably used in an amount of 20 to 80% by weight based on the total weight of the inorganic base material. If it is less than 20% by weight, the mechanical properties may not be sufficiently improved. On the other hand, if it exceeds 80% by weight, the moldability may decrease. The glass fiber is not particularly limited, but chopped strands can be used, for example. The chopped strand preferably has an average fiber diameter of 3 to 15 μm and a fiber length of 1.5 to 6.0 mm.

The molding material of the present invention is characterized in that, in addition to the above-mentioned materials, a thermoplastic polyurethane resin (c) is added to improve the impact resistance of the molded product. Polyurethane resin has a urethane bond (-NHCOO) in the main chain.
-) Is a synthetic polymer having polyisocyanates having two or more isocyanate groups (-NCO),
It is generally produced by a polyaddition reaction with polyhydroxy compounds (polyol compounds). Polyurethane resins include a network structure thermosetting type and a linear structure type thermoplastic resin, but the one used in the present invention is a thermoplastic polyurethane having a linear structure, and other general Like the conventional thermoplastic resin, it can be easily molded.

The thermoplastic polyurethane resin used in the present invention (hereinafter simply referred to as "polyurethane resin") is not particularly limited, but is solid at room temperature and has a softening point of 80 to 1
It is preferably 20 ° C. By using such a property, during the production of the molding material, the workability is excellent at the time of premixing at room temperature, and the polyurethane resin melts when kneading with a heat roll or the like, so that uniform mixing with other raw materials is possible. Will be easier. The particle size of the polyurethane resin is not particularly limited, but the average particle size is 10 to 15
It is preferably 0 μm, more preferably 30 to
It is 130 μm. Further, the shape of the polyurethane resin is not particularly limited, but a spherical shape is preferable. By using those having such a particle size and shape, the polyurethane resin can be more uniformly dispersed in the molding material from the stage of premixing the materials, and the impact resistance improving effect of the molded product can be enhanced.

The blending amount of the polyurethane resin is not particularly limited, but it is preferably 5 to 25 parts by weight, more preferably 5 to 20 parts by weight, relative to 100 parts by weight of the unsaturated polyester resin. By setting the blending amount within such a range, the workability at the time of manufacturing the molding material is excellent, and the impact resistance can be improved without deteriorating the electrical characteristics of the molded product. If the compounding amount of the polyurethane resin is less than the lower limit value, the effect of improving the impact resistance may not be sufficient, while if it exceeds the upper limit value, viscosity increase at the time of manufacturing the molding material may occur, which hinders formation of the molding material. May occur.

In the molding material of the present invention, a composition of a molding material containing an unsaturated polyester resin and an inorganic base material as essential components,
By blending a polyurethane resin, the impact resistance of the molded product is improved. The polyurethane resin has a feature that it is excellent in water resistance, oil resistance, particularly flexibility and impact resistance even when it is used alone, and can be easily molded and processed like a general thermoplastic resin. By blending the polyurethane resin with the unsaturated polyester resin, the polyurethane resin having excellent impact resistance can be dispersed in the crosslinked structure of the unsaturated polyester resin. This exerts the effect of alleviating the brittleness of the unsaturated polyester resin, and can improve the impact resistance of the molded product. Furthermore, when a spherical particle having a particle size of 10 to 150 μm is used, it can be dispersed uniformly when it is made into a molding material, and the above-mentioned action can be made more effective.

In the molding material of the present invention, in addition to the raw materials described above, a reaction initiator of an unsaturated polyester resin is usually used. The reaction initiator is not particularly limited, but for example, peroxides such as dicumyl peroxide and tert-butyl peroxide are generally used. In addition to the above, if necessary, raw materials such as a release agent, a pigment, a silane coupling agent, etc. may be blended within a range not impairing the objects and effects of the present invention.

The molding material of the present invention can be manufactured by a conventional method. That is, the above-mentioned materials are mixed in a predetermined amount and premixed by using a ribbon blender, a planetary mixer or the like. Further, it can be obtained by melt-kneading this using a heating roll, a twin-screw extrusion kneader, and the like, granulating the kneaded product, cooling and crushing and classifying.

[0017]

The present invention will be described with reference to the following examples. After premixing the composition having the composition shown in Table 1 (the compounding amounts all represent% by weight), the composition was kneaded with a heating roll at 90 ° C. for 5 minutes, cooled and pulverized to obtain a molding material. An injection molding machine (molding condition: using the obtained molding material) according to JIS K 6911.
A test piece was prepared with a mold temperature of 165 ° C. and a curing time of 4 minutes, and the characteristics were measured, and the results shown in Table 2 were obtained.

[0018]

[Table 1] (Note to the table) * 1 Unsaturated polyester resin (paratype): Dainippon Ink and Chemicals "Polylite PB-958", softening point 86 ° C * 2 Polyurethane resin: Nippon Polyurethane "Pearl Sen U-100A" (average) 40μm particle size, spherical shape,
Softening point 95 ° C) * 3 Polyurethane resin: Nippon Polyurethane "Pearl Sen U-100B" (average particle size 120 µm, spherical shape, softening point 95 ° C) * 4 Glass fiber (chopped strand): Nippon Sheet Glass "RES015-" BM42 "(average fiber diameter 11μ
m, fiber length 1.5 mm) * 5 Inorganic base material: calcium carbonate * 6 Reaction initiator: dicumyl peroxide * 7 Release agent: calcium stearate * 8 Flame-retardant inorganic base material: aluminum hydroxide * 9 Colorant :Carbon black

[0019]

[Table 2] (Note to the table) * 10 Bending strength, bending elastic modulus, Charpy impact strength,
Insulation resistance: According to JIS K6911. * 11 Solder heat resistance: Immersed in a solder bath at 270 ° C. for 30 seconds, and those having no change in appearance were evaluated as ◯.

As shown in Tables 1 and 2, in each of Examples 1 to 4, unsaturated polyester resin, glass fiber, calcium carbonate and aluminum hydroxide as an inorganic base material were used, and a polyurethane resin was compounded in the molding. It is a material. Molded articles made of these molding materials have substantially no difference in bending strength, solder heat resistance and insulation resistance as compared with Comparative Examples containing no polyurethane resin, but are represented by Charpy impact strength. Impact resistance is improved. Also,
Since the bending elastic modulus was small, it was also excellent in flexibility.

[0021]

Industrial Applicability The present invention is an unsaturated polyester resin molding material characterized by containing an unsaturated polyester resin, an inorganic base material, and a polyurethane resin as essential components. Excellent impact resistance can be imparted without impairing the electrical characteristics and heat resistance of the material. Therefore, the present invention is useful as an unsaturated polyester resin molding material used for molded articles having excellent mechanical properties, which are useful for applications of small electronic parts.

Claims (3)

[Claims] 1. An unsaturated polyester resin molding material containing an unsaturated polyester resin (a), an inorganic base material (b), and a thermoplastic polyurethane resin (c) as essential components. 2. The unsaturated polyester resin (a) in an amount of 15 to 30% by weight and the inorganic base material (b) in an amount of 50 based on the whole molding material.
The unsaturated polyester resin molding material according to claim 1, which contains 5 to 25 parts by weight of the thermoplastic polyurethane resin (c) with respect to 100 parts by weight of the unsaturated polyester resin (a). . 3. The thermoplastic polyurethane resin (c) has a spherical shape with an average particle size of 10 to 150 μm.
Alternatively, the unsaturated polyester resin molding material described in 2.