JPH03115342A - Polypropylene resin composition - Google Patents

Abstract

PURPOSE:To prepare a polypropylene resin compsn. excellent in heat resistance, particularly in the high-temp., rigidity by compounding a polypropylene resin, a polyamide resin having a melt viscosity which is in a specific relation with the melt viscosity of the polypropylene resin, and a modified polyolefin. CONSTITUTION:The title resin compsn. comprises 94-50wt.% pref. 90-55wt.%, polypropylene resin (e.g. an ethylene-propylene copolymer), 1-40wt.%, pref. 3-30wt.%, modified polyolefin (e.g. an ethylene-vinyl acetate copolymer grafted with glycidyl methacrylate), and 5-40wt.%, pref. 10-40wt.%, polyamide resin pref. having a high terminal amino group content, and has a ratio (etaA/etaC) of the melt viscosity of the polypropylene resin (etaA) to that of the polyamide resin (etaC) of higher than 1, pref. higher than 2, each at a molding temp. of 180-350 deg.C and a shear rate of 100/sec.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a polypropylene resin composition, and more specifically, it has both the excellent properties of a polypropylene resin composition and a polyamide resin, and has excellent heat resistance, especially in a high temperature atmosphere. The present invention relates to a polypropylene resin composition that has excellent heat resistance and rigidity and is suitable for automobile parts, OA equipment parts, etc.

[Prior art and problems to be solved by the invention]-a. Polypropylene resin is relatively inexpensive and has good properties such as being soft with almost no water absorption in practical use, so it is used in a wide range of fields. has been done. However, heat resistance, particularly shape retention (heat resistance rigidity) under a high temperature atmosphere, for example, around 150 to 180'C, is generally insufficient in many cases because it is near the melting point of polypropylene resin. Therefore, its application to fields where heat resistance is required, specifically, automotive exterior parts that require a baking temperature of about 150 to 170°C during the painting process, has been restricted.

Conventionally, in order to improve such properties, filling of various fillers, crosslinking of the resin portion, blending with other highly heat resistant resins, etc. have been carried out. However, the heat resistance of the resin compositions obtained in this way is not improved to a satisfactory extent, and even if they are effective to some extent, other properties such as rigidity and moldability are significantly impaired, or they are significantly impaired. There were problems such as an increase in price, and there were many cases where it could not be put into practical use.

Therefore, the present inventors conducted extensive research to develop a resin composition with excellent heat resistance, especially heat-resistant rigidity under high-temperature atmospheres, without impairing the properties of polypropylene resin. It has been discovered that the desired resin composition can be obtained by blending a polyamide resin and a modified polyolefin that have the following relationship. The present invention was completed based on this knowledge.

[Means to solve the problem]

That is, the present invention is based on (A) polypropylene resin 94-5.
0% by weight, (B) 1 to 40% by weight of modified polyolefin, and (C) polyamide resin 5 to 40% by weight, and the melt viscosity of the polypropylene resin (A) at a molding temperature and a shear rate of 100 seconds ηrr ( poi
se) and (C) polyamide resin melt viscosity 77PA (
The purpose of the present invention is to provide a polypropylene resin composition characterized in that the ratio of potse) satisfies the formula (1).

In the present invention, (A) polypropylene resin (hereinafter (A)
) Ingredients. ), a propylene homopolymer and/or a propylene copolymer is used. Here, the propylene copolymer includes propylene-ethylene copolymer, propylene-butene-1 copolymer, etc.
These block copolymers and random copolymers are used.

In addition, for this polypropylene resin, a propylene homopolymer or a propylene copolymer may be used alone, or two or more types may be used in combination. At this time, the molecular weight of the propylene homopolymer and propylene copolymer is not particularly limited, but generally the melt flow rate (MFR
) of 0.01 to 50 g/10 min is preferably used.

Next, (B) modified polyolefin in the present invention (hereinafter ((
B) Indicated as component. ) as carboxylic acid group (acetate group,
Acrylic acid group, methacrylic acid group.

fumaric acid group, itaconic acid group, etc.), carboxylic acid metal bases (sodium salt, calcium salt, magnesium salt, zinc salt, etc.), carboxylic acid ester group (methyl ester group,
It is a polyolefin having at least one functional group selected from ethyl ester group, propyl ester group, butyl ester group, vinyl ester group, etc.), acid anhydride group (maleic anhydride group, etc.), and epoxy group. Examples of the polyolefin include polyethylene, polypropylene, polybutene, ethylene/propylene copolymer, ethylene/butene copolymer, ethylene/hexene copolymer, and copolymers containing a small amount of diene. .

Specific examples of such modified polyolefins include ethylene/acrylic acid copolymer, ethylene/methacrylic acid copolymer, ethylene/fumaric acid copolymer, ethylene/methacrylic acid/zinc methacrylate copolymer, and ethylene/acrylic acid copolymer. Acid/sodium methacrylate copolymer, ethylene/
Isobutyl acrylate/methacrylic acid/zinc methacrylate copolymer, ethylene/methyl methacrylate/methacrylic acid/magnesium methacrylate copolymer, ethylene/
Ethyl acrylate copolymer, ethylene/vinyl acetate copolymer, ethylene/glycidyl methacrylate copolymer, ethylene/vinyl acetate/glycidyl methacrylate copolymer, maleic anhydride grafted polyethylene, acrylic acid grafted polyethylene, maleic anhydride Grafted polypropylene.

Maleic anhydride kraft ethylene/propylene copolymer, acrylic acid grafted ethylene/propylene copolymer,
Fumaric acid grafted ethylene/1-butene copolymer, ethylene/1-hexene-itacone M copolymer, ethylene/
Propylene-endobicyclo(2,2,1)-5-hebutene-2,3-dicarboxylic anhydride copolymer, ethylene/
Propylene-grafted glycidyl methacrylate copolymer.

Maleic anhydride grafted ethylene/propylene/1.4
-Hexadiene copolymer, fumaric acid grafted ethylene/
These modified polyolefins include propylene/dicyclopentadiene copolymer, maleic acid grafted ethylene/propylene/norbornadiene copolymer, and acrylic acid grafted ethylene/vinyl acetate copolymer, and these modified polyolefins may be used alone, or It is also possible to use two or more types together.

The above-mentioned modified polyolefin can be produced by known methods, for example, Japanese Patent Publication No. 39-6810, Japanese Patent Publication No. 46-27527, Japanese Patent Publication No. 50-2630, Japanese Patent Publication No. 52-43.
Publication No. 677, Special Publication No. 53-5716, Special Publication No. 577
It can be produced according to the methods disclosed in Japanese Patent Publication No. 3-19037, Japanese Patent Publication No. 53-41173, Japanese Patent Publication No. 56-9925, and the like. Regarding ethylene ionomers, “Surlyn” and “Himilan°” are generally used.
, various grades commercially available under the trade name 'Corpolene' can be used.Also, there is no particular restriction on the degree of polymerization of the modified polyolefin used in the present invention, but
Generally, one having a melt index within the range of 0.01 to 100 g/10 minutes can be arbitrarily selected.

Furthermore, (C) polyamide resin used in the present invention (hereinafter ((
Various materials can be used as component C), specifically nylon 6, nylon 11. Polylactams such as nylon 12; nylon 66, nylon 6
10. Polyamides obtained from dicarboxylic acids and diamines such as nylon 6/2゜nylon 46; nylon 6/
66, nylon 6/12. Copolymer polyamides such as nylon 6/66/610; nylon 6/6T (T: terephthalic acid component), semi-aromatics obtained from aromatic dicarboxylic acids such as isophthalic acid and metaxylene diamine or alicyclic diamine Polyamides; mention may be made of polyesteramides, polyetheramides and polyesteretheramides.

In addition, as the polyamide resin of the component (C), the above-mentioned various polyamides may be used alone, or two or more types of polyamides may be used in combination.

Furthermore, the polyamide resin of component (C) that can be used in the present invention is not limited by the type, concentration, molecular weight, etc. of the terminal group of these polyamides, as long as it is selected from the above-mentioned polyamides. can be used, but highly amino-terminated polyamides are particularly preferred. Further, it is also possible to use a polyamide in which low molecular weight substances such as polymers and oligomers that remain or are generated during polymerization of the polyamide are mixed.

In the composition of the present invention, various components as described above can be used as components (A) to (C), but among these,
Between component (A) and component (C), the ratio of the melt viscosity of component (A), 77 rr (poise), and the melt viscosity of component (C), ηrA (poise) at the molding temperature and shear rate of 100 sec'' is , formula (1゛ηPF/ηP
A11...(Npreferably η, 7/η2.>2... [B] It is necessary to select a combination of those that satisfy the following.Here, the value of η1./η, A is 1 or less. If this is the case, the polyamide resin will form a dispersed phase, making it impossible to impart the desired heat-resistant rigidity to the resulting resin composition, which is undesirable. It is the temperature when molding the composition to produce various molded products,
Generally it is in the range of 180-350°C.

In the present invention, the blending ratio of the three components (A), (B), and (C) is 94 to 50% by weight of component (A), preferably 90 to 55% by weight, and 1 to 40% by weight of component (B). % by weight, preferably 3 to 30% by weight, component (C) 5 to 40% by weight,
Preferably it is 10 to 40%.

Here, if the blending ratio of component (A) is less than 50% by weight,
The resulting resin composition has the original Q of polypropylene resin,
p), and if it is blended in an amount exceeding 94% by weight, the effect of improving heat resistance stiffness cannot be obtained, which is not preferable.

Furthermore, if the blending ratio of component (B) is less than 1% by weight, (A
It is insufficient to improve the compatibility between component ) and component (C), and even if the amount exceeds 40% by weight, the effect corresponding to the blending ratio is small, and rather the other components of the resulting resin composition This results in deterioration of various physical properties. Furthermore, if the blending ratio of (C)-component is less than 5% by weight, the effect of improving heat resistance stiffness is insufficient, and if the blending ratio exceeds 40% by weight, (A)
This is not preferable because the blending ratio of the components decreases and the original properties of the polypropylene resin are lost.

The resin composition of the present invention includes the above (A), (B) and (C).
), but if necessary, other additives may be added as long as they do not impede the properties of the above components. Additives that can be added here include dyes, R materials, fillers, nucleating agents, fibrous materials, plasticizers, lubricants, mold release agents, coupling agents, foaming agents, heat resistant agents, weathering agents, flame retardants, and antistatic agents. agent.

Examples include sliding agents.

The resin composition of the present invention is a resin composition formed by blending the above three components and additives added as necessary in predetermined amounts. There is no particular restriction on the order of blending, and each component may be blended sequentially or simultaneously. Further, components (B) and (C) may be blended with component (A) in powder or pellet form after the polymerization reaction is completed.

The resin composition of the present invention is prepared by mixing or kneading each component in the above-mentioned proportions, and a conventionally known melt-kneading method is preferred. Mixing is carried out using a Banbury mixer, a Henschel mixer, etc., and a single-screw or two-wheel extruder is generally used as the kneader. The temperature during melt-kneading may be appropriately selected depending on the components, blending amounts, etc., at a temperature at which the melting of each component progresses sufficiently and does not decompose. It is usually selected in the range of 180 to 350°C, preferably 200 to 300°C.

The obtained resin composition may be molded into any desired shape by extrusion molding, compression molding, injection molding, etc. to produce desired resin products such as pipes and tubes. Furthermore, processing such as plating and painting can be applied afterwards.

〔Example〕

Next, the present invention will be explained in more detail based on Examples and Comparative Examples.

The various physical properties of the polyamide resin compositions obtained on each side below were measured based on the following test methods.

Test pieces were prepared by molding the composition using a screw in-line injection molding machine. The cylinder temperature at this time is 28
0°C1 Also, the mold temperature was 60°C.

According to ASTM-D-648, bending stress 4.6 kgf
The heat distortion temperature was measured at /CTA.

Using a cavilograph manufactured by Toyo Seiki Co., Ltd., the temperature was set at 28.
The melt viscosity (η1.) of the polypropylene resin and the melt viscosity (ηPA) of the polyamide resin at a shear rate of 1005 ec-' at 0°C1 were measured.

Examples 1 to 11 and Comparative Examples 1 to 4 Pellets of each of polypropylene resin, modified polyolefin, and polyamide resin shown in Table 1 were blended in the prescribed amounts shown in Table 1, and after dry mixing for 5 minutes with a Henschel mixer, The resulting mixture was melt-kneaded in a vented co-directional twin-screw extruder (inner diameter 30 mm, L/D=17) to produce pellets.

Note that the heating temperature at the time of making this pellet was 280'C.

The obtained pellets were heated and dried under reduced pressure, and then made into test pieces using an injection molding machine, and the heat distortion temperature was measured. The results are shown in Table 1. In addition, this Table 1 shows 280°C1
The ratio of melt viscosity of the polypropylene resin and polyamide resin at a shear rate of 100 sec (η2./ηP
A) is also shown.

(Left below) 1: Propylene homopolymer, JIS K 675B
Propylene homopolymer with MFR of 0.5 g/10 min *2: Propylene homopolymer, JIS K 675
Propylene homopolymer with MFR of 3 g/10 min at 8 *3: Propylene block copolymer, JIS K
Propylene block copolymer with MFR of 0.8 g/IO at 6758 *4: Propylene homopolymer, JIS K 675
Propylene homopolymer with MFR at 8 of 30 g/10 min *5: Propylene block copolymer, JIS K
Propylene block copolymer with MFR of 30 g/10 min at 6758 *6; graft modified polypropylene, MF at 230°C
Graft-modified polypropylene obtained by adding 0.35% by weight of maleic anhydride to tactical polypropylene having R of 1.0 g/10 minutes *7: Glycidyl methacrylate grafted ethylene-
Vinyl acetate copolymer was produced with reference to the method described in Japanese Patent Publication No. 12449/1983. That is, glycidyl methacrylate in which dicumyl peroxide had been dissolved in advance was mixed with ethylene-vinyl acetate copolymer pellets, and the mixture was allowed to penetrate at room temperature. Next, the glycidyl methacrylate-impregnated pellets were extruded using a co-directional twin-screw extruder with an inner diameter of 30 mm and a vent at a tip temperature of 170°C to obtain graft-polymerized epoxy group-containing copolymer pellets (glycidyl methacrylate content: 2 wL). %).

*8: Nylon 66. Relative viscosity 2.85. Amino end group concentration 5.2×10-' equivalent/g*9: Nylon 66.
Relative viscosity 2.30. Amino end group concentration 5.1X10-
'Equivalent weight/g*10: Nylon 6. Relative viscosity 2.52. Amino terminal group concentration 4.9X10-' equivalent/g [Effects of the invention] As explained above, the polypropylene resin composition of the present invention maintains the excellent properties of polypropylene resin, while
This resin composition has excellent heat resistance, particularly high heat-resistant rigidity, and also has the excellent properties of the polyamide resin blended with it. Such a resin composition of the present invention is particularly suitable as a material for parts and the like that require heat resistance, heat-resistant rigidity, and the like.

Therefore, the polypropylene resin composition of the present invention can be widely and effectively used as a material for parts that require heat resistance, heat-resistant rigidity, etc., such as automobile parts, electrical appliances, mechanical parts, and industrial parts.

Claims (1)

[Claims] (1) (A) Polypropylene resin 94-50% by weight, (
B) consisting of 1 to 40% by weight of modified polyolefin and (C) 5 to 40% by weight of polyamide resin, and the above (A) at a molding temperature and a shear rate of 100 sec^-^1
Melt viscosity of polypropylene resin η_P_P (poise
) and (C) the melt viscosity η_P_A(po
A polypropylene resin composition characterized in that the ratio of .ise) satisfies the formula [I] η_P_P/η_P_A>1...[I].