Resin composition, sheet molding compound, and molded article

Abstract

To provide a resin composition from which a molded article having viscosity and flame retardancy with excellent production suitability and excellent weight saving can be obtained.SOLUTION: A resin composition contains a resin component (A) containing an unsaturated polyester resin (a1) and styrene (a2), and contains 1-6 pts.mass of a wetting dispersant (B), 15-40 pts.mass of a glass balloon (C) and 10-30 pts.mass of a flame retardant (D) with respect to 100 pts.mass of the resin component (A). There are provided a sheet molding compound containing the resin composition and a reinforcement fiber (F), and a molded article molded from the sheet molding compound.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resin composition, a sheet molding compound, and a molded article. [Background technology]

[0002] Sheet molding compound (hereinafter sometimes abbreviated as "SMC") is a sheet-shaped molding material obtained by impregnating fibers with a paste (compound) made by kneading thermosetting resins, mainly consisting of unsaturated polyester resins and vinyl ester resins, inorganic fillers, thickeners, hardeners, etc., and then maturing the material to the B stage. Molded products are obtained by heating and pressurizing this SMC. Such molded products have excellent durability, water resistance, mechanical strength, etc., and are widely used as housing components such as bathtubs, water tanks, septic tanks, pipe lining materials, electrical parts, vehicle materials, aircraft materials, etc. In particular, vehicle materials and aircraft materials are required to be lightweight, and high flame retardancy is required for parts other than exterior parts.

[0003] A method for making molded products lighter has been known for a long time, for example, by adding hollow fillers such as hollow glass beads and glass microballoons, while a method for making molded products flame-retardant has been known, for example, by adding aluminum hydroxide or phosphorus- or bromine-based flame retardants.

[0004] For example, bulk molding compounds (BMC) with a specific gravity of 1.20 have been reported as a way to reduce the weight of molded products (see, for example, Patent Document 1), but there have been no reports of sheet molding compounds that are both flame retardant and have a specific gravity of 1.2. The reason for this is that SMC requires a process in which the compound is impregnated into long glass fibers, and therefore the compound viscosity must be set lower than that of BMC. Thus, in the field of SMC, all of the methods for reducing weight and making the compound flame retardant have the problem of increasing the compound viscosity, and it has been considered difficult to achieve both weight reduction and flame retardancy at a practical level. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2006-206690 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a resin composition which has excellent viscosity, flame retardancy, and lightweight properties and is suitable for production. [Means for solving the problem]

[0007] The present invention provides a resin composition comprising a resin component (A) containing an unsaturated polyester resin (a1) and styrene (a2), characterized in that the resin composition contains 1 to 6 parts by mass of a wetting and dispersing agent (B), 15 to 40 parts by mass of glass balloons (C), and 10 to 30 parts by mass of a flame retardant (D) relative to 100 parts by mass of the resin component (A).

[0008] The present invention also provides a sheet molding compound containing the resin composition and reinforcing fibers (F), and a molded article molded from the sheet molding compound. Effect of the Invention

[0009] The resin composition of the present invention can provide a molded article having excellent viscosity, flame retardancy, and light weight, which is excellent in manufacturability. Therefore, the resin composition of the present invention can be particularly suitably used in applications requiring light weight and flame retardancy, such as vehicle materials and aircraft materials. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The resin composition of the present invention is a resin composition containing a resin component (A) that contains an unsaturated polyester resin (a1) and styrene (a2), and contains 1 to 6 parts by mass of a wetting and dispersing agent (B), 15 to 40 parts by mass of glass balloons (C), and 10 to 30 parts by mass of a flame retardant (D) relative to 100 parts by mass of the resin component (A).

[0011] The resin component (A) contains an unsaturated polyester resin (a1) and styrene (a2) as essential components, but may also contain a thermosetting resin (a3) ​​other than the unsaturated polyester resin (a1), a polymerizable unsaturated monomer (a4) other than the styrene (a2), and a low shrinkage agent (a5), etc.

[0012] The unsaturated polyester resin (a1) in the resin component (A) has a high viscosity, and is therefore preferably diluted with styrene (a2) before mixing with other components, and is preferably used as a styrene solution having a non-volatile content of 30 to 80 mass %. The unsaturated polyester resin (a1) can be used alone or in combination of two or more kinds.

[0013] The wetting and dispersing agent (B) is preferably a polymeric wetting and dispersing agent having an acid group, and specific examples thereof include polymeric wetting and dispersing agents manufactured by BYK Japan Co., Ltd., such as BYK-W940, BYK-W972, BYK-W974, BYK-W996, BYK-W9010, BYK-W9011, Disper-BYK110, Disper-BYK111, and Disper-BYK180. These wetting and dispersing agents (B) can be used alone or in combination of two or more kinds.

[0014] The glass balloons (C) are, for example, glass micro hollow sphere powders made of chemically stable insoluble glass, having a particle diameter of about 16 to 65 μm (median diameter) and a true density of 0.13 to 0.60 g / cm. 3Examples of glass balloons include those having a perfect sphere of about 1 mm. Glass balloons manufactured by 3M Japan Ltd., such as Glass Bubbles S32HS, Glass Bubbles iM16K, and Glass Bubbles K46, are commercially available glass balloons.

[0015] Examples of the flame retardant (D) that can be used include bromine-based flame retardants, inorganic salts such as antimony trioxide and antimony pentoxide, red phosphorus-based flame retardants, nitrogen-based flame retardants such as melamine cyanurate and melamine polyphosphate, and phenol-based flame retardants such as phenol-based flame retardants. These flame retardants may be used alone or in combination of two or more. Among these, one or more selected from the group consisting of bromine-based flame retardants, antimony trioxide, and red phosphorus-based flame retardants are preferred from the viewpoint of maintaining high levels of flame retardancy, manufacturability, and light weight.

[0016] Examples of the brominated flame retardant include brominated aliphatic or alicyclic hydrocarbons such as hexabromocyclododecane, brominated aromatic compounds such as hexabromobenzene, ethylenebispentabromodiphenyl, decabromodiphenylethane, decabromodiphenyl ether, octabromodiphenyl ether, and 2,3-dibromopropylpentabromophenyl ether, tetrabromobisphenol A, tetrabromobisphenol A bis(2,3-dibromopropyl ether), tetrabromobisphenol A(2-bromoethyl ether), tetrabromobisphenol A diglycidyl ether, and tetrabromobisphenol A diglycidyl ether. Brominated bisphenols and derivatives thereof, such as an adduct of tetrabromobisphenol A diglycidyl ether and tribromophenol, brominated bisphenol derivative oligomers, such as an epoxy oligomer of an adduct of tetrabromobisphenol A diglycidyl ether and brominated bisphenol, brominated aromatic compounds, such as ethylene bistetrabromophthalimide and bis(2,4,6-tribromophenoxy)ethane, brominated acrylic resins, ethylene bisdibromonorbornane dicarboximide brominated flame retardants, etc., can be used. These flame retardants may be used alone or in combination of two or more.

[0017] As the red phosphorus-based flame retardant, for example, red phosphorus, red phosphorus particles whose surfaces are coated with a resin such as a phenolic resin, etc., can be used. Among these, red phosphorus particles whose surfaces are coated with a resin are preferred because they are more safe and have better dispersibility when mixed with a resin component.

[0018] The resin composition of the present invention contains the resin (A), the wetting dispersant (B), the glass balloons (C), and the flame retardant (D) as essential components, but the amount of each is extremely important. Specifically, it is essential to contain 1 to 6 parts by mass of the wetting dispersant (B), 15 to 40 parts by mass of the glass balloons (C), and 10 to 30 parts by mass of the flame retardant (D) relative to 100 parts by mass of the resin component (A) in order to obtain excellent manufacturability, flame retardancy, and light weight, and more preferably, the ranges are 2 to 6 parts by mass of the wetting dispersant (B), 15 to 34 parts by mass of the glass balloons (C), and 10 to 20 parts by mass of the flame retardant (D) relative to 100 parts by mass of the resin component (A). Within these ranges, excellent flame retardancy and light weight can be obtained while suppressing an increase in the viscosity of the compound.

[0019] The resin composition of the present invention may contain other additives, in addition to the above-mentioned (A) to (D), as necessary.

[0020] Examples of the other additives that can be used include inorganic fillers (E), reinforcing fibers (F), polymerization initiators, thickeners, polymerization inhibitors, curing accelerators, shrinkage reducing agents, release agents, viscosity reducing agents, pigments, antioxidants, plasticizers, flame retardants, antibacterial agents, UV stabilizers, reinforcing materials, and photocuring agents. These compounds may be used alone or in combination of two or more. Among these, when the resin composition of the present invention is used as a sheet molding compound, it is preferable to contain inorganic fillers (E) and reinforcing fibers (F).

[0021] Examples of the inorganic filler (E) include calcium carbonate, sodium hydroxide, clay, talc, kaolin, silica, etc. These compounds may be used alone or in combination of two or more kinds.

[0022] The amount of the inorganic filler (E) used is preferably within a range of 20 to 80 parts by mass per 100 parts by mass of the resin component (A).

[0023] Examples of the reinforcing fiber (F) include glass fiber, carbon fiber, silicon carbide fiber, alumina fiber, boron fiber, metal fiber, aramid fiber, vinylon fiber, tetron fiber, and other organic fibers, and glass fiber or carbon fiber is preferred because it provides a molded product with higher strength and elasticity. These reinforcing fibers (F) can be used alone or in combination of two or more kinds.

[0024] The length of the reinforcing fibers (F) is preferably within a range of 3 to 60 mm from the viewpoint of the cuttability of the fibers themselves and impregnation with the resin component (A). Reinforcing fibers of different lengths may be mixed.

[0025] The content of the reinforcing fibers (F) in the molding material of the present invention is preferably in the range of 10 to 50 mass %, more preferably in the range of 15 to 35 mass %, since the mechanical strength of the resulting molded article is further improved.

[0026] The resin composition of the present invention is useful as a sheet molding compound (SMC). Examples of the method for producing the SMC include a method in which the components (A) to (E) are mixed and dispersed using a mixer such as a normal mixer, intermixer, planetary mixer, roll, kneader, or extruder, the obtained resin composition is applied to a carrier film placed above and below so as to have a uniform thickness, reinforcing fiber (F) is sandwiched between the resin composition on the carrier films placed above and below, and then the whole is passed between impregnation rolls to impregnate the reinforcing fiber (F) with the resin composition by applying pressure, and then wound into a roll or folded in a zigzag shape. Furthermore, it is preferable to carry out aging at a temperature of 25 to 55°C after this. As the carrier film, a polyethylene film, a polypropylene film, a laminate film of polyethylene and polypropylene, polyethylene terephthalate, nylon, etc. can be used.

[0027] The molded article of the present invention is obtained from the above-mentioned SMC, and from the viewpoints of excellent productivity and excellent design versatility, the molding method is preferably hot compression molding of SMC.

[0028] The heat compression molding is, for example, a manufacturing method in which a molding material such as SMC is weighed out in a predetermined amount, put into a mold preheated to 80 to 180°C, the mold is clamped with a compression molding machine, the molding material is shaped, and the molding material is cured by maintaining a molding pressure of 0.1 to 30 MPa, and then the molded product is taken out to obtain a molded product. Specific molding conditions are preferably a mold temperature of 100 to 160°C in the mold and a molding pressure of 1 to 10 MPa for 1 to 2 minutes per mm of thickness of the molded product, and more preferably a mold temperature of 120 to 160°C and a molding pressure of 1 to 10 MPa for 30 to 150 seconds per mm of thickness of the molded product, because this improves productivity.

[0029] As described above, the resin composition of the present invention can provide a molded article having excellent viscosity, flame retardancy, and light weight, which is suitable for manufacturing. Therefore, the resin composition of the present invention can be particularly suitably used in applications requiring light weight and flame retardancy, such as vehicle materials and aircraft materials. EXAMPLES

[0030] The present invention will now be described in more detail with reference to specific examples.

[0031] [Example 1] Preparation of resin composition (1) 80 parts by mass of an unsaturated polyester resin solution ("Sandoma PS-281" manufactured by DIC Materials Co., Ltd.; a mixture of 60% by mass of unsaturated polyester resin and 40% by mass of styrene), 15 parts by mass of a polystyrene resin solution ("Sandoma PS-954" manufactured by DIC Corporation; a mixture of 30% by mass of polystyrene and 70% by mass of styrene), 5 parts by mass of styrene, 0.1 parts by mass of a polymerization inhibitor ("Parabenzoquinone" manufactured by Seiko Chemical Co., Ltd.), 5 parts by mass of a wetting and dispersing agent ("BYK-W9010" manufactured by BYK-Chemie Co., Ltd.), 4 parts by mass of zinc stearate, 70 parts by mass of aluminum hydroxide, 18 parts by mass of glass balloons ("Glass Bubbles S32HS" manufactured by 3M Japan Ltd.), 9 parts by mass of decabromodiphenylethane, 3 parts by mass of antimony trioxide, 1 part by mass of magnesium oxide, and 1.5 parts by mass of a polymerization initiator ("Trigonox 22-70E" manufactured by Nouryon Chemical Co., Ltd.) were mixed by a dissolver to obtain a resin composition (1).

[0032] [SMC Manufacturing] The resin composition (1) obtained above was uniformly applied onto two polypropylene carrier films placed above and below, and 70.5 parts by mass of glass fiber ("PB-549" manufactured by Nitto Boseki Co., Ltd.) cut to 25.4 mm was sandwiched between the resin composition on the carrier films placed above and below. The whole was passed between impregnation rolls to apply pressure to impregnate the glass fiber with the resin composition, and then cured at 45°C for 24 hours to obtain SMC (1) with a glass fiber content of 25 mass%.

[0033] [Example 2] Preparation of resin composition (2), production of SMC (2) A resin composition (2) was obtained in the same manner as in Example 1, except that in Example 1, the amount of aluminum hydroxide used was changed from 70 parts by mass to 45 parts by mass, the amount of glass balloons used was changed from 18 parts by mass to 20 parts by mass, the amount of decabromodiphenylethane used was changed from 9 parts by mass to 12 parts by mass, and the amount of antimony trioxide used was changed from 3 parts by mass to 4 parts by mass. An SMC (2) was obtained in the same manner as in Example 1, except that the amount of glass fiber used was changed from 70.5 parts by mass to 64.2 parts by mass.

[0034] [Example 3] Preparation of resin composition (3), production of SMC (3) A resin composition (3) was obtained in the same manner as in Example 1, except that in Example 1, the amount of wetting dispersant used was changed from 5 parts by mass to 6 parts by mass, the amount of aluminum hydroxide used was changed from 70 parts by mass to 30 parts by mass, the amount of glass balloons used was changed from 18 parts by mass to 24 parts by mass, the amount of decabromodiphenylethane used was changed from 9 parts by mass to 12 parts by mass, and the amount of antimony trioxide used was changed from 3 parts by mass to 4 parts by mass. An SMC (3) was obtained in the same manner as in Example 1, except that the amount of glass fiber used was changed from 70.5 parts by mass to 60.9 parts by mass.

[0035] [Example 4] Preparation of resin composition (4), production of SMC (4) A resin composition (4) was obtained in the same manner as in Example 1, except that in Example 1, the amount of wetting dispersant used was changed from 5 parts by mass to 6 parts by mass, the amount of aluminum hydroxide used was changed from 70 parts by mass to 30 parts by mass, the amount of glass balloons used was changed from 18 parts by mass to 24 parts by mass, the amount of decabromodiphenylethane used was changed from 9 parts by mass to 16 parts by mass, and the amount of antimony trioxide used was changed from 3 parts by mass to 0 parts by mass. An SMC (4) was obtained in the same manner as in Example 1, except that the amount of glass fiber used was changed from 70.5 parts by mass to 60.9 parts by mass.

[0036] [Example 5] Preparation of resin composition (5), production of SMC (5) In Example 1, the amount of the wetting dispersant used was changed from 5 parts by mass to 6 parts by mass, the amount of aluminum hydroxide used was changed from 70 parts by mass to 30 parts by mass, the amount of glass balloons used was changed from 18 parts by mass to 24 parts by mass, the amount of decabromodiphenylethane used was changed from 9 parts by mass to 0 parts by mass, the amount of antimony trioxide used was changed from 3 parts by mass to 0 parts by mass, and 16 parts by mass of red phosphorus ("Nova Red 120" manufactured by Rin Kagaku Kogyo Co., Ltd.) were newly added. In addition, a resin composition (5) was obtained in the same manner as in Example 1, except that the amount of glass fiber used was changed from 70.5 parts by mass to 60.9 parts by mass.

[0037] [Example 6] Preparation of resin composition (6), production of SMC (6) A resin composition (6) was obtained in the same manner as in Example 1, except that in Example 1, the amount of wetting dispersant used was changed from 5 parts by mass to 6 parts by mass, the amount of aluminum hydroxide used was changed from 70 parts by mass to 30 parts by mass, the amount of glass balloons used was changed from 18 parts by mass to 30 parts by mass, the amount of decabromodiphenylethane used was changed from 9 parts by mass to 12 parts by mass, and the amount of antimony trioxide used was changed from 3 parts by mass to 4 parts by mass. An SMC (6) was obtained in the same manner as in Example 1, except that the amount of glass fiber used was changed from 70.5 parts by mass to 62.9 parts by mass.

[0038] Comparative Example 1: Preparation of resin composition (R1) and production of SMC (R1) A resin composition (R1) was obtained in the same manner as in Example 1, except that in Example 1, the amount of wetting dispersant used was changed from 5 parts by mass to 10 parts by mass, the amount of aluminum hydroxide used was changed from 70 parts by mass to 30 parts by mass, the amount of glass balloons used was changed from 18 parts by mass to 35 parts by mass, the amount of decabromodiphenylethane used was changed from 9 parts by mass to 12 parts by mass, and the amount of antimony trioxide used was changed from 3 parts by mass to 4 parts by mass. An SMC (R1) was obtained in the same manner as in Example 1, except that the amount of glass fiber used was changed from 70.5 parts by mass to 65.9 parts by mass.

[0039] Comparative Example 2: Preparation of resin composition (R2) and production of SMC (R2) A resin composition (R2) was obtained in the same manner as in Example 1, except that in Example 1, the amount of wetting dispersant used was changed from 5 parts by mass to 6 parts by mass, the amount of aluminum hydroxide used was changed from 70 parts by mass to 30 parts by mass, the amount of glass balloons used was changed from 18 parts by mass to 24 parts by mass, the amount of decabromodiphenylethane used was changed from 9 parts by mass to 6 parts by mass, and the amount of antimony trioxide used was changed from 3 parts by mass to 2 parts by mass. An SMC (R2) was obtained in the same manner as in Example 1, except that the amount of glass fiber used was changed from 70.5 parts by mass to 58.2 parts by mass.

[0040] [Method of evaluating light weight] The SMC obtained in the examples and comparative examples was peeled off and cut into pieces of 265 mm x 265 mm. Three pieces were stacked together to make a 30 x 30 cm 2 The molded product was cut to a size of 40 mm x 40 mm, and the specific gravity of the molded product was measured using an electronic specific gravity meter. "Good": The specific gravity of the molded product is 1.3 or less. "×": Specific gravity of molded product exceeds 1.3.

[0041] [Manufacturing suitability evaluation method] In the examples and comparative examples, a resin composition containing glass fibers was prepared at 30°C, 1 ml of the composition was sampled, and the viscosity was measured using a cone-plate viscometer (40P cone, rotor rotation speed: 50 rpm). The viscosity was evaluated as follows. "Good": Viscosity is 26 Pa s or less. "×": Viscosity exceeds 26 Pa s.

[0042] [Flame retardancy evaluation method] The SMC obtained in the examples and comparative examples was peeled off and cut into pieces of 265 mm x 265 mm. Three pieces were stacked together to make a 30 x 30 cm 2 The molded product was placed in the center of a flat plate mold and molded at a mold temperature of 150°C for 5 minutes with a pressure of 12 MPa to obtain a flat plate molded product with a thickness of 3 mm. This was subjected to a flammability test (UL-94V test) and was evaluated as follows. 「〇」;V-0 "×";V-1 or less

[0043] [Table 1]

[0044] [Table 2]

[0045] As seen from Examples 1 to 6, the resin composition of the present invention was found to have excellent viscosity, flame retardancy, and weight reduction, which are suitable for manufacturing.

[0046] On the other hand, in Comparative Example 1, the amount of the wetting and dispersing agent (B) used exceeded the range specified in the present invention, but the flame retardancy and manufacturability were poor.

[0047] In Comparative Example 2, the amount of flame retardant (D) used was below the range specified in the present invention, but the flame retardancy was poor.

Claims

1. A sheet molding compound comprising a resin composition including a resin component (A) including an unsaturated polyester resin (a1) and styrene (a2), and a reinforcing fiber (F), Relative to 100 parts by mass of the resin component (A), 1 to 6 parts by mass of a wetting and dispersing agent (B), 15 to 40 parts by mass of glass balloons (C), The flame retardant (D) is contained in an amount of 10 to 30 parts by mass, The flame retardant (D) is at least one selected from the group consisting of bromine-based flame retardants, antimony trioxide, red phosphorus-based flame retardants, and nitrogen-based flame retardants; The reinforcing fiber (F) is at least one selected from the group consisting of glass fiber and carbon fiber, A sheet molding compound, characterized in that the specific gravity of the resulting molded article is 1.3 or less.

2. The sheet molding compound according to claim 1, further comprising an inorganic filler (E) selected from the group consisting of aluminum hydroxide, calcium carbonate, sodium hydroxide, clay, talc, kaolin, and silica in an amount of 20 to 80 parts by mass per 100 parts by mass of the resin component (A).

3. A molded product made from the sheet molding compound according to claim 1 or 2.

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