TW201843227A - Polyolefin resin composition and molded polyolefin resin composition - Google Patents

Abstract

A polyolefin resin composition which comprises (A) an olefin polymer, (B) fibrous basic magnesium sulfate, and (C) glass fibers, wherein the proportion shown by expression 1 is in the range of 1-42 mass%, the proportion shown by expression 2 is 40 mass% or less, and the proportion shown by expression 3 is in the range of 0.5-75 mass%; and a molded polyolefin resin composition which is a molded object comprising the polyolefin resin composition. ((B+C)/(A+B+C))*100 expression 1 (C/(A+B+C))*100 expression 2 (B/(B+C))*100 expression 3 (In the expressions, A, B, and C respectively indicate the contents of the olefin polymer, fibrous basic magnesium sulfate, and glass fibers in the polyolefin resin composition.).

Description

   Polyolefin resin composition and polyolefin resin composition molded body   

The present invention relates to a polyolefin resin composition and a molded article of a polyolefin resin composition, and more particularly to a polyolefin resin composition and a molded article of a polyolefin resin composition containing a fibrous inorganic filler.

Polyolefin resins represented by polypropylene resins are widely used as exterior materials for automobiles or interior materials, exterior materials for household appliances such as refrigerators and washing machines, and various moldings such as trays, trays, and packaging sheets. Body manufacturing materials. In addition, in order to improve the physical properties such as rigidity and impact resistance of a molded article of a polyolefin resin composition, a polyolefin resin composition added with a filler (filler) is generally widely used. The fillers used for this purpose are generally fibrous inorganic fillers and non-fibrous inorganic fillers.

For example, Patent Document 1 describes a polyolefin resin composition containing a fibrous inorganic filler. In this document, a fibrous magnesium oxysulfate (magnesium sulfate) containing (A) a polyolefin resin at 20 to 60% by weight and (B) granulated to an average particle diameter of 0.1 to 5 mm and a bulk specific gravity of 0.15 to 0.4 is disclosed (oxysulfate) a polyolefin resin composition made of 15 to 60% by weight and (C) 5 to 40% by weight of glass fiber. According to this document, with such a structure, it is possible to provide a polyolefin resin composition that does not generate a halogen gas during combustion and has excellent flame retardancy and high mechanical strength.

In the example of Patent Document 1, a resin composition is disclosed in which the polypropylene resin is 30 to 50% by mass, the fibrous magnesium oxysulfate is 20 to 45% by mass, and the glass fiber is 10 to 30% by mass. The total amount of the fibrous magnesium oxysulfate and the glass fiber is 50% by mass or more. Moreover, in the comparative example of this document, although the example of 70 mass% of polypropylene resin was described (comparative examples 1, 2), only any fibrous magnesium sulfate or glass fiber was blended in any comparative example. Moreover, the fibrous magnesium oxysulfate of this document is one which is granulated to have an average particle diameter of 0.1 to 5 mm.

In Patent Document 2, a document containing 40% to 99% by weight of propylene-ethylene interpolymer (A) and 1% to 60% by weight of fiber (B) is described (however, the total amount of (A) and (B) is 100% by weight) of a fiber-reinforced polypropylene resin composition. Here, the fiber (B) is at least one selected from the group consisting of glass fiber, carbon fiber, whisker, and organic fiber having a melting point of 245 ° C. or higher, and alkaline magnesium sulfate fiber (paragraph 0007) is exemplified as the whisker. According to this document, by having such a structure, it is possible to provide a low shrinkage, good texture transferability, scratch resistance, and molding appearance, smooth and soft touch of the surface of the molded body without foaming, and Fiber-reinforced polypropylene resin composition with high rigidity, high impact strength, and high heat resistance.

Although Patent Document 2 discloses basic magnesium sulfate fiber as a whisker, the example using alkaline magnesium sulfate fiber is not described in the examples, and the combination with glass fiber is not described.

On the other hand, a technique of combining a fibrous inorganic filler and a non-fibrous inorganic filler is also known. Patent Document 3 describes a polyolefin resin composition that contains a polyolefin resin and fibrous basic magnesium sulfate particles in an amount ranging from 99: 1 to 50:50 in a mass ratio, and is based on the fibrous alkali. Non-fibrous inorganic fine particles having an average particle size in the range of 0.001 to 0.5 μm in 100 parts by mass of the magnesium sulfate particles containing 0.001 to 50 parts by mass, and / or 0.0002 to 10 per 100 parts by mass of the resin The non-fibrous inorganic fine particles having an average particle size in a range of 0.001 to 0.5 μm in an amount in a part by mass. According to this document, by having such a structure, it is possible to provide a polyolefin resin composition capable of producing a resin molded body having a high-order balance of impact resistance and rigidity.

    Prior art literature         Patent literature    

Patent Document 1: Japanese Patent Application Laid-Open No. 2-305836

Patent Document 2: Japanese Patent Application Laid-Open No. 2013-067789

Patent Document 3: Japanese Patent Application Publication No. 2016-191036

As can be seen from Tables 2 and 3 of Patent Document 1, if the blending ratio of the fibrous filler (the total amount of fibrous magnesium sulphate and glass fiber) to the polypropylene resin becomes higher, the flexural modulus of elasticity will change. high. On the other hand, in general, there is a trade-off relationship between the flexural modulus and the Izod impact strength. It is known that if the ratio of the blending amount of the fibrous filler increases, the Izod impact strength decreases. Therefore, in Patent Document 1, it is difficult to simultaneously increase both the bending elastic modulus and the Aicot impact strength. Further, if the ratio of the fibrous filler to the polypropylene resin is relatively excessively high, the fibrous filler may rise out of the surface of the molded body in a large amount, so that the appearance may be deteriorated.

An object of the present invention is to provide a polyolefin resin composition which can improve both the flexural modulus of elasticity and the impact strength of a molded article of a polyolefin resin composition, and can also have a good appearance. Furthermore, another object of the present invention is to provide a polyolefin resin composition molded body in which both the flexural modulus of elasticity and the impact strength of Axotec are improved and the appearance is also good.

In order to achieve the above object, the present inventors have conducted intensive research and found that in a resin composition in which an olefin polymer is blended with a fibrous filler, fibrous alkaline magnesium sulfate and glass fiber are used in combination as a fibrous filler And, if the blending ratio is within a specified range, both the bending elastic modulus and the Aicot impact strength of the molded article of the polyolefin resin composition can be improved, and the present invention has been completed.

That is, the present invention is a polyolefin resin composition containing at least (A) an olefin polymer, (B) fibrous basic magnesium sulfate, and (C) glass fibers, the fibrous basic magnesium sulfate and the glass fibers. The ratio (((B + C) / (A + B + C)) × 100) of the total amount to the total amount of the olefin polymer, the fibrous alkaline magnesium sulfate, and the glass fiber is 1 to 42% by mass Within this range, the ratio of the total amount of the glass fiber to the total amount of the olefin polymer, the fibrous alkaline magnesium sulfate, and the glass fiber ((C / (A + B + C)) × 100) is 40. The mass ratio of the fibrous alkaline magnesium sulfate to the total amount of the fibrous alkaline magnesium sulfate and the glass fiber ((B / (B + C)) × 100) is in the range of 0.5 to 75% by mass. Inside.

Here, it is preferable that the above-mentioned fibrous alkaline magnesium sulfate has an average major axis in a range of 5 to 50 μm, and an average minor axis in a range of 0.1 to 2.0 μm.

The present invention is a molded article of a polyolefin resin composition, which is a molded article of the polyolefin resin composition described in any one of the above.

According to the present invention, it is possible to provide a polyolefin resin composition that can improve both the flexural modulus of elasticity and the impact strength of the molded article of a polyolefin resin composition, and can also give good appearance. Moreover, according to this invention, the polyolefin resin composition molded body which improved both the bending elastic modulus and the Aicot punching strength, and also has a favorable external appearance can be provided.

1. Polyolefin resin composition

Hereinafter, the polyolefin resin composition of the present invention will be described. The polyolefin resin composition of the present invention contains at least (A) an olefin polymer, (B) fibrous alkaline magnesium sulfate, and (C) glass fibers. Hereinafter, each component will be described.

(1) olefin polymer

Examples of the olefin polymer include an ethylene polymer, a propylene homopolymer, a random copolymer, and a block copolymer. A propylene polymer is particularly preferred, and a block copolymer is more preferred. The olefin polymer may be used alone or in combination of two or more. The melt flow rate (MFR) of the olefin polymer is usually in the range of 3 to 300 g / 10 minutes, preferably in the range of 10 to 100 g / minute.

The content of the olefin polymer is in a range of 58 to 99% by mass, and more preferably in a range of 60 to 95% by mass with respect to the entire amount of the polyolefin resin composition. If the content of the olefin polymer is less than 58% by mass, the ratio of the olefin polymer contained in the polyolefin resin composition will be relatively low and the ratio of the fibrous filler will be relatively high. The molded article of polyolefin resin composition obtained by molding has a lack of flexibility. In addition, if the content of the olefin polymer is less than 56% by mass, the number of fibrous fillers will increase relatively, so the number of fibrous fillers protruding from the surface will increase, and the appearance will easily deteriorate. On the other hand, if the content of the olefin polymer is more than 99% by mass, the ratio of the fibrous filler will be relatively too low, so the impact strength and flexural modulus of Aicot tend to be low.

(2) Fibrous alkaline magnesium sulfate

Fibrous basic magnesium sulfate can be obtained by hydrothermal synthesis, for example, using magnesium hydroxide and magnesium sulfate produced from seawater as raw materials. The average major axis of the fibrous alkaline magnesium sulfate is generally in a range of 5 to 50 μm, and preferably in a range of 10 to 30 μm. The average minor axis of the fibrous alkaline magnesium sulfate is generally in the range of 0.1 to 2.0 μm, and preferably in the range of 0.2 to 1.0 μm.

The average aspect ratio (average major axis / average minor axis) of the fibrous alkaline magnesium sulfate is generally 2 or more, preferably 5 or more, and most preferably 5 to 50. The average long axis and the average short axis of the fibrous alkaline magnesium sulfate can be calculated from the average values of the long axis and the short axis of 100 particles measured from a magnified image of a scanning electron microscope (SEM). The fibrous basic magnesium sulfate may be an aggregate or a combination of a plurality of fibrous particles.

The content of the fibrous alkaline magnesium sulfate is generally in the range of 0.01 to 31.5% by mass, preferably in the range of 0.01 to 20% by mass, and more preferably in the range of 0.05 to 15% by mass relative to the overall amount of the polyolefin resin composition. . If the content of the fibrous alkaline magnesium sulfate is less than 0.01% by mass, the ratio of the fibrous alkaline magnesium sulfate contained in the polyolefin resin composition will be relatively low, and the polyolefin resin composition obtained by molding the polyolefin resin composition will be molded. Both the impact strength and flexural modulus of elasticity of the body are easily reduced. On the other hand, if the content of the fibrous basic magnesium sulfate is higher than 31.5% by mass, the ratio of the fibrous basic magnesium sulfate contained in the polyolefin resin composition will be relatively excessively high, and the processability will be deteriorated or The appearance easily deteriorates.

(3) glass fiber

The glass fiber can be suitably used by general users. The shape of the glass fibers is not particularly limited, and chopped strands, roving, milled fibers, and the like can be used.

The average long axis of the glass fiber is generally in the range of 0.5 to 20 mm, and preferably in the range of 1 to 10 mm. The average minor axis of the glass fiber is generally within a range of 1 to 50 μm, and preferably within a range of 5 to 30 μm.

The average aspect ratio (average major axis / average minor axis) of the glass fiber is generally 2 or more, preferably in the range of 4-20. The average major axis and the average minor axis of the glass fibers can be calculated from the results measured with a scanning electron microscope in the same manner as the fibrous alkaline magnesium sulfate.

Glass fiber can be used without surface treatment, but in order to improve mechanical strength, it can also be surface treated with a surface treatment agent. Examples of the surface treatment agent include epoxy silanes such as γ-glycidoxypropyltrimethoxysilane, ethylene silanes such as ethylene trichlorosilane, and silanes such as γ-aminopropyl triethoxysilane Couplings.

The content of the glass fiber is generally in the range of 1 to 40% by mass, preferably in the range of 2 to 40% by mass, and more preferably in the range of 2 to 38% by mass relative to the entire amount of the polyolefin resin composition. If the content of the glass fiber is less than 1% by mass, the ratio of the glass fiber contained in the polyolefin resin composition will be relatively low. The bending elastic modulus is easily lowered. On the other hand, when the content of the glass fiber is higher than 40% by mass, the ratio of the glass fiber contained in the polyolefin resin composition becomes relatively excessively high, and the appearance is liable to be poor.

The ratio of the total amount of (B) fibrous basic magnesium sulfate and (C) glass fiber to the total amount of (A) olefin polymer, (B) fibrous basic magnesium sulfate, and (C) glass fiber (from the following The value represented by Formula 1) is in the range of 1 to 42% by mass, and more preferably in the range of 7 to 42% by mass.

((B + C) / (A + B + C)) × 100‧‧Formula 1

(Here, A, B, and C respectively represent the content of the olefin polymer, fibrous alkaline magnesium sulfate, and glass fiber contained in the polyolefin resin composition.)

If the value of the above formula 1 is less than 1% by mass, since the ratio of the content of the fibrous filler (the total amount of the fibrous basic magnesium sulfate and the glass fiber) contained in the polyolefin resin composition is relatively low, it is obtained The flexural modulus of elasticity and the impact strength (especially the flexural modulus) of the polyolefin resin composition molded body tend to be low. On the other hand, if the value of the above formula 1 is higher than 42% by mass, the content ratio of the fibrous filler contained in the polyolefin resin composition will be relatively excessively high, so the obtained polyolefin resin composition molded body is easy to obtain. bad apperance.

In particular, glass fibers are larger than alkaline magnesium sulfate, so they easily affect the appearance. Therefore, the ratio of the total amount of glass fibers to the total amount of olefin polymer, fibrous alkaline magnesium sulfate, and glass fibers (value represented by the following formula 2) is preferably 40% by mass or less.

(C / (A + B + C)) × 100‧‧Formula 2

(Here, A, B, and C are the same as the above-mentioned formula 1.)

The ratio of (B) fibrous alkaline magnesium sulfate to (B) the total amount of fibrous alkaline magnesium sulfate and (C) glass fiber (value represented by the following formula 3) is in the range of 0.5 to 75% by mass. , More preferably in the range of 3 to 45% by mass.

(B / (B + C)) × 100‧‧Formula 3

(Here, B and C are the same as the above-mentioned formula 1.)

If the value of the above formula 3 is less than 0.5% by mass, the ratio of the fibrous basic magnesium sulfate contained in the fibrous filler will be relatively low, so that the obtained polyolefin resin composition molded body has a high Aicot punch strength. Go low. On the other hand, if the value of the above formula 3 is higher than 75% by mass, the content ratio of the fibrous alkaline magnesium sulfate contained in the fibrous filler will be relatively high, and the flexural modulus of the obtained polyolefin resin composition molded body will be high. The number easily becomes low.

In the present invention, the values of the formulas 1 to 3 are within a predetermined numerical range, both the flexural modulus of elasticity of the polyolefin resin composition molded article and the impact strength of Aicot can be improved, and the appearance can also be improved. good.

As long as the effect of the present invention is not hindered, other components may be blended in the polyolefin resin composition. Examples of other components include antioxidants, ultraviolet absorbers, pigments, antistatic agents, copper inhibitors, flame retardants, neutralizers, foaming agents, plasticizers, nucleating agents, foam suppressants, and cross-linking agents.联 剂 Such as. The content of the other components is preferably 11% by mass or less, and more preferably 0.1% by mass or less of the entire polyolefin resin composition.

2. Polyolefin resin composition molded body

Next, a polyolefin resin composition molded body will be described. The polyolefin resin composition molded article of the present invention is a molded article of the polyolefin resin composition. The molded article of the polyolefin resin composition of the present invention has excellent characteristics such that Aicot's impact strength and flexural modulus are high, and its appearance is also good.

(1) Achot's impact strength

Axot impact strength is an index showing the strength of a polyolefin resin composition molded body against punching. The value of the Aicot impact strength in this specification can be defined as the result measured by the method described in the examples described later. Specifically, it is a measurement result using a notching machine and the method based on JISK7110.

(2) Flexural modulus

The flexural modulus of elasticity is an index indicating the ease of deformation of a molded article of a polyolefin resin composition. The value of the bending elastic modulus in this specification can be defined as a result measured by the method described in the examples described later. Specifically, it is a result of measurement using a universal testing machine and a method based on JISK7171.

(3) Appearance

The external appearance indicates the smoothness of the surface of a molded article of a polyolefin resin composition. The appearance in the present specification can be defined as a result measured by a method described in Examples described later. Specifically, the surface of the molded body was photographed using a digital microscope to visually evaluate the surface roughness.

The polyolefin resin composition molded body can be produced by molding the polyolefin resin composition. Examples of the method for molding the polyolefin resin composition include a method of mixing the components constituting the polyolefin resin composition to produce a polyolefin resin composition and molding the same; or a masterbatch pellet ( (Master batch pellet) and diluted granules (diluted material) are melt-kneaded to prepare a polyolefin resin composition and shaped; or a method of mixing master batch granules and diluted granules and directly molding the mixture by a molding machine. As the diluent, a resin containing the olefin polymer may be mentioned. Examples of the molding machine used for molding include calender molding machines (such as calendar molding machines), vacuum molding machines, extrusion molding machines, injection molding machines, blow molding machines, and processing machines. Press forming machines, etc.

Hereinafter, the present invention will be specifically described based on examples, but these are not intended to limit the purpose of the present invention, and the present invention is not limited by these examples.

1. Example 1

Polypropylene resin [MFR (temperature 230 ° C, load 2.16 kg): 52 g / min] 95 parts by mass of fibrous basic magnesium sulfate particles (made by MOS A-1, UBE MATERIALS (strand), average long axis: 15 μm, The average minor axis: 0.5 part by mass, 2.5 parts by mass of glass fiber (CS (F) 3-PE-960S, manufactured by Nittobo Corporation, fiber length: 3 mm, fiber minor axis: 13 μm) were mixed. Using a biaxial melt-kneading extruder (L / D = 25, manufactured by Imoto Co., Ltd.), the obtained mixture was melt-kneaded at a temperature of 230 ° C and a shaft revolution of 90 rpm to melt the resulting melt. The kneaded material is extruded into a strand shape and then cut to obtain particles of a polypropylene resin composition containing fibrous basic magnesium sulfate particles and glass fibers.

2.Examples 2 to 24

A polypropylene resin composition particle was obtained in the same manner as in Example 1 except that the blending amount of the polypropylene resin, glass fiber, and fibrous basic magnesium sulfate particles was the ratio shown in Table 1.

3. Comparative Example 1

A polypropylene resin composition particle was obtained in the same manner as in Example 1 except that the polypropylene resin was 95 parts by mass, and the blending amount of the fibrous alkaline magnesium sulfate particles was 5 parts by mass without glass fiber. .

4. Comparative Examples 2 to 10

A polypropylene resin composition particle was obtained in the same manner as in Comparative Example 1 except that the blending amounts of the polypropylene resin, glass fiber, and fibrous basic magnesium sulfate particles were as shown in Table 1.

For the above examples and comparative examples, the ratio of the content of (A) polypropylene resin, (B) fibrous alkaline magnesium sulfate, and (C) glass fiber to the total amount of fibrous filler with respect to each component ((B The value of + C) / (A + B + C)) is aggregated with the value of the ratio of fibrous alkaline magnesium sulfate to the total amount of fibrous alkaline magnesium sulfate and glass fiber (B / (B + C)).于 表 1。 In Table 1.

(Note) A: blending amount of polypropylene resin (unit: part by mass) B: blending amount of fibrous alkaline magnesium sulfate particles (unit: part by mass) C: blending amount of glass fiber (unit: part by mass) ) B / (B + C): Blending ratio of fibrous basic magnesium sulfate particles when the total blending amount of glass fibers and fibrous basic magnesium sulfate particles is 100 parts by mass (unit: mass%)

<Evaluation method>

Using a small-sized injection molding machine (C. Mobile0813, manufactured by Shin Selbic Co., Ltd.), the polypropylene resin composition particles obtained in the examples and comparative examples were injection-molded to produce test pieces. The test piece was slender with a length of 50 mm, a width of 5 mm, and a thickness of 2 mm.

Using the produced test piece, Aicot's impact strength and flexural modulus were measured by the following methods.

‧Achute punch strength: Measured by a method based on JISK7110 using an angle cutter (made by Imoto Co., Ltd.).

‧Bending elastic modulus: A three-point bending test was performed using a universal testing machine (made by IMADA), and the load deflection curve obtained was measured by a method in accordance with JISK7171. The distance between the fulcrum points was 40 mm, and the load speed was 10 mm / min.

Using the produced test piece, the appearance of the test piece was evaluated by the following method.

‧Examination of test piece appearance: Using a digital microscope (CZ-ST Type-s, manufactured by Kyowa Optical Industry Co., Ltd.), the surface of the test piece was photographed, and the appearance was judged and evaluated. When it is judged that the rough feeling is not obvious, the appearance is evaluated as good (○), and when the rough feel is obvious, the appearance is evaluated as bad (×).

Combine the results of Aicot's impact strength, flexural modulus and appearance with the values of "(B + C) / (A + B + C)" and "B / (B + C)" described in Table 1 above. It is shown in Table 2 below.

From the results shown in Table 2, it can be seen that compared with the molded article produced using a polypropylene resin composition (Examples 1 to 24) containing a polypropylene resin, fibrous alkaline magnesium sulfate particles, and glass fibers within the scope of the present invention, A molded article manufactured using a polypropylene resin composition (Comparative Example 1 and the like) containing only polypropylene resin and fibrous basic magnesium sulfate particles has the same flexural modulus or exhibits a higher value. The value of special impact strength has been increased.

Claims (3)

    A polyolefin resin composition containing at least (A) an olefin polymer, (B) fibrous alkaline magnesium sulfate, and (C) glass fibers, and a total amount of the fibrous alkaline magnesium sulfate and the glass fibers relative to the olefin The total ratio of the polymer, the fibrous alkaline magnesium sulfate, and the glass fiber (((B + C) / (A + B + C)) × 100) is in the range of 1 to 42% by mass. The glass The ratio of the total amount of the fiber to the total amount of the olefin polymer, the fibrous alkaline magnesium sulfate, and the glass fiber ((C / (A + B + C)) × 100) is 40% by mass or less. The fiber The ratio ((B / (B + C)) × 100) of the basic alkaline magnesium sulfate to the total amount of the fibrous alkaline magnesium sulfate and the glass fiber is in a range of 0.5 to 75% by mass.         The polyolefin resin composition according to claim 1, wherein the average major axis of the fibrous alkaline magnesium sulfate is generally within a range of 5 to 50 μm, and the average minor axis is within a range of 0.1 to 2.0 μm.         A molded article of a polyolefin resin composition is a molded article of the polyolefin resin composition according to claim 1 or 2.