JPS62167342A - Polypropylene resin composition - Google Patents

Abstract

PURPOSE:A lightweight resin composition suitable as part materials for heat generation part, having improved mechanical strength and heat distortion temperature and further good thermal conductivity, obtained by blending a polypropylene resin with graphite and an inorganic filler in a specific ratio. CONSTITUTION:(A) A polypropylene resin, a polymer preferably having >=80% residue after boiling h-heptan extraction and 0.4-100g/10min melt flow rate is blended with (B) graphite having <=100mu, preferably <=80mu average particle diameter and an inorganic filler such as glass fibers, calcium carbonate, barium sulfate, etc., having preferably <=20mu fiber diameter in the case of fibrous form or <=100mu, preferably <=40mu average particle diameter in the case of fine power form in such a way that the formula I - formula III (X is volume % of the component B; Y is volume % of the component C) are simultaneously satisfied and preferably further the formula IV and the formula V are satisfied to give a resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a polypropylene resin composition having excellent mechanical strength teK and excellent heat conductivity.

[Prior art and its problems]

Polypropylene resin is laterally reinforced with glass fiber, Merck, calcium carbonate, and other inorganic fillers and is used in a wide range of applications as a material for industrial parts due to its excellent mechanical strength and heat resistance. However, in recent years, performance requirements for materials have become more sophisticated and diversified, and there are many fields that conventional composite reinforced resins cannot meet. For example, when used in mechanical parts where the temperature rises due to heat generation, the amount of heat generated is large;
If the temperature of the parts is close to the melting point of polypropylene resin, it is impossible to use even composite reinforced polypropylene resin. This is because the polypropylene resin itself or the filled and reinforced polypropylene resin itself has poor heat conductivity and low heat dissipation, so heat is accumulated and the temperature rise of the resin is accelerated. Furthermore, known compositions consisting of polypropylene resin and gutphite, or polypropylene resin and inorganic fillers such as glass fibers are insufficient to satisfy both heat conductivity and mechanical strength. Furthermore, polypropylene resin mixed with metal powder or gold R fiber can be considered as the next material for the purpose of improving heat conductivity, but although these improve heat conductivity, the mechanical strength and heat distortion temperature are satisfactory. Moreover, the specific gravity increases when metals are added, and the material does not meet the purpose of reducing the weight of mechanical parts by turning it into a resin.

As described above, the inventors of the present invention have found that they are lightweight, have excellent mechanical strength and heat distortion temperature, and have good heat conductivity (heat dissipation). [Means and effects for solving the problems] The present invention focuses on providing a component material for the heat generating part, and as a result of intensive study, the UliJt of the present invention was completed. (the volume of the composition is X vot%) and an inorganic filler (the volume % of the composition is Y voL%)
Provided is a reinforced polypropylene resin composition characterized in that the blending ratio of

X+1. osY≦43.2 (1)x-0.0
8y≧4.5 (2)-X+18Y≧69.
2 (3) The polypropylene resin used in the present invention is a propylene homopolymer or a copolymer of propylene and other α-olefins such as ethylene and butene 1, and these can be used alone or in a blend.

Preferably, boiling n-hebutane extraction residue (Igota
ctic Index=hereinafter referred to as II. ) is 80%
As described above, a polymer having a melt flow rate of 0.4 to 100 r/10 cm as measured by ASTM D 1238 is used.

(9) The graphite used in the present invention may be either an artificial or a natural product, and may have a scale-like, lump-like, or bead-like shape. Furthermore, the average particle size is 100μ
It may be less than 80μ, preferably less than 80μ.

Furthermore, known inorganic fillers can be used in the present invention. For example, oxides of Sl, oxides, hydroxides, silicates, carbonates, or silicates of Ca, MP, and Ba, oxides, hydroxides, or silicates of M, and these as part of the composition. Examples include hydrates or double salts of compounds containing such compounds, minerals, and carbon-based fillers. More specifically, glass fiber, calcium carbonate, Merck, barium sulfate,
Calcium silicate, clay, magnesium carbonate, alumina, silica, calcium sulfate, white carbon,
Aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, asbestos, zeolite, diatomaceous earth, calcium hydroxide, mica, V-gnesium oxide,
These include pumice, dolomite, dawsonite, and carbon fiber, and these may be man-made or natural. In addition, the shape may be either fibrous or fine powder. For example, fibrous materials such as glass fiber and carbon fiber can be used in either long fiber or short fiber shape, but the average fiber diameter is A thickness of 20μ or less is desirable. In addition, fine powder is
It is desirable that the average particle diameter is 100μ or less, preferably 40μ or less. The average particle size mentioned above is measured by a sedimentation method, which is usually used to measure the particle size of powder. For example, the inorganic filler of the present invention may be used alone or as a mixture of two or more.

In addition, the graphite and inorganic filler used in the present invention can be coupled with a polypropylene resin by a known method,
Or use known treatment methods to improve affinity and enhance physical properties, such as silane coupling agents, titanium coupling agents, higher fatty acids, fatty acid metal salts, fatty acid and organic acid esters and amides, organic acids, resins. It is desirable to perform chemical or physical surface treatment using a treatment agent such as an acid.

In addition, a known auxiliary agent that enhances coupling or affinity may be used in combination.

Regarding the relationship of the blending ratio, firstly, if it is outside the range of formula (1), the fluidity during molding will be poor, the molding processability will be impaired, and the strength, particularly the impact strength, will be impaired. If it is outside the range of formula (2), the effect of improving heat conductivity (heat dissipation), which is the main objective of the present invention, will not be sufficient. If it is outside the range of formula (3), the heat deformation resistance is insufficient. Preferably, (1), (
2), (3) and the following formulas (4) and (5) at the same time, and has moldability, heat conductivity (heat dissipation),
A composition with well-balanced strength and heat deformation resistance can be obtained.

X-1,45Y≦9.28 (4)X-
0,78Y≧-10,4(5) The material of the present invention may contain pigment colorants, clearing agents, lubricants, antistatic agents, crosslinking agents, flame retardants, and other additives as long as the purpose of the present invention is not impaired. It's okay to include it.

The material of the present invention is lightweight and has excellent mechanical strength, heat distortion temperature, and heat conductivity (heat dissipation), and due to its improved heat conductivity (heat dissipation), it can be used as a material for mechanical parts that generate heat. For example, housing parts used in parts of motors, parts in automobile engine compartments, etc. that surround heat generating parts, parts used in contact with heat generating parts, and materials for parts that are subject to stress. It is suitable as

〔Example〕

This will be explained below using examples.

Describe the inner wall temperature used as a parameter for heat conductivity (heat dissipation) in Examples or Comparative Examples.
FI 4. Or/io w), graphite (manufactured by Tokai Carbon ■, average particle diameter 42 tones) and inorganic fillers (e.g.
A predetermined amount of the blended composition of Salt 7 Eyeperglass (9μ) fibers was cross-extruded using an extruder to obtain moldable, uniform pellets of the polypropylene resin composition.

This is molded using an injection molding machine to a depth of 60 m5 and an inner diameter of 120 mm x 8.
A box-shaped molded product with a thickness of 0w5 and 2cm was molded. 23℃
The opening of this molded product (120 m J x 8
0 m) down on the firebrick, and
It has a built-in heater that emits heat of v. The temperature was measured in advance with a specific thermocouple attached to the inner wall surface of the molded product, and the temperature at which equilibrium was reached was defined as the inner wall temperature.

In addition, the tensile strength, Izot impact strength, flexural modulus, and heat distortion temperature are determined by ASTM D-ea s and AST, respectively.
MD-256, ASTM D-7901ASTM D
-648 measurement method was followed.

Example 1 Polypropylene resin (homopolymer 1196.9%, M
The inner wall temperature and tensile strength of a composition containing graphite (Tokai Carbon, average particle diameter 42μ), and glass fiber (Asahi Fiberglass, fiber diameter 9μ), 11.4VAT , Izot impact strength, flexural modulus, and heat distortion temperature were measured.

The results are shown in Table 1.

Example 2 Polypropylene resin similar to that used in Example 1 with graphite x9.1vot'16 and glass fiber 17.2
The composition containing votS was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 3 Graphite lo, 6 vot% and glass plate fiber 9.6 voL were added to the same polypropylene resin used in Example 1.
The same evaluation as in Example 1 was performed on the composition containing %. The results are shown in Table 1.

Example 4 Graphite s, ovot% and glass fiber 5.0vot% were added to the same polypropylene resin as used in Example 1.
The same evaluation as in Example 1 was performed for all the blended compositions. The results are shown in Table 1.

Comparative Example 1 Graphite 28.1 vot% and glass fiber 19.1 voL were added to the same polypropylene resin as used in Example 1.
The same evaluation as in Example 1 was performed on the composition containing H. The results are shown in Table 1.

Comparative Example 2 A composition in which 13.4 vots of glass fiber was blended with the same polypropylene resin as used in Example 1 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3 Regarding a composition in which 14.6 vot% of graphite was blended with the same polypropylene resin used in Example 1,
The same evaluation as in Example 1 was performed. result? Shown in Table 1.

Example 5 22.5 vot% of graphite and 7.5 vot% of glass fiber were added to the same polypropylene resin as used in Example 1.
The same evaluation as in Example 1 was performed on the composition containing the following. The results are shown in Table 1.

Example 6 Polypropylene resin (ethylene content 8.5 parts by weight)
89. Graphite (same as Example 1) 19.1 VOJ and glass fiber (Same as Example 1) 17.2 MAO 1% were blended into nine compositions. The same evaluation as in Example 1 was performed. The results are shown in Table 2.

Example 7 The same polypropylene resin used in Example 6 was blended with 10,5 vots of graphite and 9.6 ml of glass fiber, and the same evaluation as in Example 1 was conducted on the composition. The results are shown in Table 2.

Example 8 Polypropylene resin (same as Example 1) with graphite (same as Example 1) 10.7 vo/J and calcium carbonate surface treated with 1% by weight of acrylic acid (average particle size 2, a) 8.9 The same evaluation as in Example 1 was performed on the composition containing vot%. The results are shown in Table 2.

Example 9 Graphite l was added to the same polypropylene resin as in Example 6.
o, '1vo1% and Merck (average particle size 6μ) a, 9v
The same evaluation as in Example 1 was performed on a composition containing ot%. The results are shown in Table 3.

Example 1G Graphite 1 was added to the same polypropylene resin as in Example 6.
The same evaluation as in Example 1 was performed on a composition containing 7% G and mica (average particle size lOμ). The results are shown in Table 3.

Comparative Example 4 Talc 17.4 was added to the same polypropylene resin as in Example 7.
The same evaluation as in Example 1 was performed on the composition containing vot%. The results are shown in Table 3.

Comparative Example 5 The same evaluation as in Example 1 was performed on a composition in which 25 vot% of calcium carbonate (average particle size: 2 μm) was blended with the same polypropylene resin as in Example 6.

The result is shown in the third equation.

Claims (1)

[Claims] A polypropylene resin composition characterized in that the blending ratio of polypropylene resin, graphite, and inorganic filler is within a range that simultaneously satisfies the following formulas (1), (2), and (3). X+1.08Y≦43.2(1) X-0.08Y≧4.5(2) −X+18Y≧69.2(3) However, X: Volume % value of graphite in the composition Y: Composition Volume % value of inorganic filler in