JP2695492B2 - Polyamide / polyolefin resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyamide / polyolefin resin composition, and more specifically, it has excellent characteristics of both polyamide resin and polypropylene resin, and is particularly excellent in coatability. The present invention relates to a polyamide / polyolefin resin composition.

[Problems to be solved by conventional technology and invention]

Generally, a polyamide resin is widely used as a synthetic fiber or the like because of its excellent physical and chemical properties, but in recent years, it has also been used as a molding material. This is because the polyamide resin is a thermoplastic resin, has high mechanical strength, excellent wear resistance, chemical resistance, heat resistance and relatively excellent electrical properties, and has performance as an engineering plastic. It depends on having enough. However, on the other hand, it has unfavorable performance such as dimensional change due to water absorption and deterioration of mechanical strength due to the amide group (-CONH-), which makes it marketable as a molding material. Limited.

On the other hand, polypropylene resin is inexpensive and exhibits almost no water absorbency, but it has drawbacks such as softness and poor physical properties at high temperatures.

Therefore, in order to improve the respective drawbacks of the polyamide resin and the polypropylene resin, it is naturally conceivable to use these resins together, but a resin mixture obtained by mixing the polyamide resin and the polypropylene resin by a usual method, or those The resin composition obtained by simply melt-kneading is poor in compatibility and cannot be a composition having the desired excellent physical properties.

Therefore, conventionally, a resin composition having both excellent properties of polyamide resin and polypropylene resin,
That is, a resin that has the excellent wear resistance, electrical characteristics, heat resistance, mechanical strength, and oil resistance of a polyamide resin, as well as the low water absorption, hot water resistance, metal halide resistance, and low temperature impact resistance of a polypropylene resin. For the purpose of obtaining a composition, a polyamide resin, an olfine polymer, and a modified polyolefin grafted with an unsaturated carboxylic acid or a derivative thereof are melt-mixed to obtain a balance of strength, heat distortion resistance, appearance, and moldability. Has already been disclosed in JP-B-42-12546, JP-B-45-30945, JP-B-50-7636 and the like. In addition, by utilizing such excellent properties,
Practical applications are being considered for some applications, such as automobile parts, electrical appliances, mechanical parts, and industrial parts, which require strength and heat distortion resistance, and some have already been put into practical use.

However, even a resin composition (polymer alloy composition) having such characteristics has a problem that the coatability is still insufficient. These polymer alloy compositions contain polypropylene resins, which have poorer coatability than polyamide resins, so that their applications are currently limited.

The inventors of the present invention have conducted intensive studies to maintain the excellent properties of polyamide resins and polypropylene resins while improving the paintability. As a result, they have found that the object can be achieved by appropriately combining and using a polyamide resin and a polypropylene resin having a constant relationship of the melt viscosity at the molding processing temperature, and by compounding them together with a modified polyolefin.

The present invention has been completed based on such findings.
That is, the present invention comprises (A) polyamide resin 80 to 40% by weight (excluding 40% by weight), (B) modified polyolefin 1 to 40% by weight and (C) polypropylene resin 20 to 60% by weight, Moreover, the above (A) at a molding processing temperature and a shear rate of 3500 sec ^-1
A polyamide characterized in that the ratio of the melt viscosity η _PA (poise) of the polyamide resin and the melt viscosity η _PP (poise) of the (C) polypropylene resin satisfies the formula η _PP / η _PA > 0.75 ... [I] -Providing a polyolefin resin composition.

As the (A) polyamide resin used in the present invention, various types can be used, but specifically, polylactams such as nylon 6, nylon 11, nylon 12; nylon 66, nylon 610, nylon 612, nylon 46, etc. Polyamides obtained from dicarboxylic acids and diamines; nylon 6/66,
Copolymer polyamides such as nylon 6/12, nylon 6/66/610; from aromatic dicarboxylic acids such as nylon 6 / 6T (T: terephthalic acid component), isophthalic acid and metaxylene diamine or alicyclic diamine The semi-aromatic polyamides obtained may include polyester amides, polyether amides and polyester ether amides. As the polyamide resin as the component (A), the above various polyamides may be used alone, or two or more kinds of polyamides may be used in combination.

Further, the polyamide resin that can be used in the present invention is not limited by the type, concentration and molecular weight of the end groups of these polyamides as long as it is selected from the above-mentioned polyamides, and various types can be used. However, high amino unterminated polyamides are especially preferred. It is also possible to use a polyamide in which low molecular weight substances such as monomers and oligomers that remain or are formed during polymerization of the polyamide are mixed.

Next, as the (B) modified polyolefin used in the present invention, there are various kinds, but usually, carboxylic acid groups (acetic acid group, acrylic acid group, methacrylic acid group, fumaric acid group, itaconic acid group, etc.), Carboxylic acid metal base (sodium salt, calcium salt, magnesium salt, zinc salt, etc.), carboxylic acid ester group (methyl ester group, ethyl ester group, propyl ester group, butyl ester group, vinyl ester group, etc.), acid anhydride group A polyolefin having at least one functional group selected from (maleic anhydride group and the like) and epoxy group. Examples of the polyolefin include polyethylene, polypropylene, polybutene, ethylene / propylene copolymers, ethylene / butene copolymers, ethylene / hexene copolymers, and copolymers containing a small amount of diene therein. .

Specific examples of such modified polyolefins include ethylene / acrylic acid copolymers, ethylene / methacrylic acid copolymers, ethylene / fumaric acid copolymers, ethylene / methacrylic acid / zinc methacrylate copolymers, ethylene / acrylics. 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 grafted ethylene / propylene copolymer, acrylic acid grafted ethylene / propylene copolymer, Fumaric acid-grafted ethylene / 1-butene copolymer, ethylene / 1-hexene-itaconic acid copolymer, ethylene / propylene-endobicyclo [2.2.1] -5-heptene-2,3-dicarboxylic anhydride copolymer ,ethylene/
Propylene-methacrylic acid graft glycidyl copolymer, maleic anhydride graft ethylene / propylene / 1,4
-Hexadiene copolymer, fumaric acid graft ethylene /
Propylene / dicyclopentadiene copolymer, maleic acid-grafted ethylene / propylene / norbornadiene copolymer, acrylic acid-grafted ethylene / vinyl acetate copolymer and the like, and these modified polyolefins may be used alone or in combination. It is also possible to use more than one species together.

The modified polyolefin can be produced by a known method, for example, Japanese Patent Publication No. 39-6810, Japanese Patent Publication No. 46-27527, Japanese Patent Publication No. 50-2630, Japanese Patent Publication No. 52-43677, and Japanese Patent Publication No. 53.
-5716, Japanese Patent Publication No. 53-19037, Japanese Patent Publication No. 53-411
It can be manufactured according to the method described in Japanese Patent Publication No. 73, Japanese Patent Publication No. 56-9925, etc. Regarding ethylene ionomers, "Surlyn", "Himilan",
Various grades marketed under the trade name of "COPOLEN" can be used. Further, the degree of polymerization of the modified polyolefin used in the present invention is not particularly limited, but one having a melt index in the range of 0.01 to 100 g / 10 minutes can be arbitrarily selected.

Next, as the polypropylene resin (C), a propylene homopolymer and / or a propylene copolymer is used. Here, as the propylene copolymer, there are a propylene-ethylene copolymer, a propylene-butene-1 copolymer and the like, and a block copolymer or a random copolymer thereof is used. As the polypropylene resin, one type of propylene homopolymer or propylene copolymer may be used, or two or more types may be used in combination. At this time, the molecular weights of the propylene homopolymer and the propylene copolymer are not particularly limited, but generally, those having a melt flow rate (MFR) of 1 to 50 g / 10 minutes are preferably used.

In the composition of the present invention, various components as described above can be used as the components (A) to (C). Among them, the molding processing temperature, Melt viscosity of component (A) at a shear rate of 3500 sec ^-1 η _PA (p
oise) and the melt viscosity η _PP (poise) of the components (C) have the formula η _PP / η _PA > 0.75 ... [I], preferably the formula η _PP / η _PA > 1 ... [I '] It is necessary to select those that meet the requirements. Here, if the value of η _PP / η _PA is 0.75 or less, it is not preferable because the resin composition obtained cannot be provided with desired coatability. Incidentally, the molding processing temperature here is a temperature at the time of molding various compositions by molding the composition of the present invention,
Generally, it is in the range of 180 to 350 ° C.

In the present invention, the blending ratio of each component for producing a polyamide-polyolefin resin composition having excellent coatability is (A) polyamide resin 80 to 40% by weight (correctly exceeding 40% by weight and 80% by weight). The following), preferably 80 to 45% by weight, (B) modified polyolefin 1 to 40% by weight,
It is preferably 3 to 30% by weight. The content of the (C) polyolefin resin is 20 to 60% by weight, preferably 20 to 50% by weight.

Here, when the (A) polyamide resin is 40% by weight or less,
The coatability of the resulting composition is not sufficiently improved. Conversely 80
When it exceeds the weight percentage, the original properties of the polypropylene resin are lost. Further, if the content of the (B) modified polyolefin is less than 1% by weight, it is difficult to improve the compatibility between the polyamide resin as the component (A) and the polypropylene resin as the component (C), and as a result, the resulting composition is In some cases, it may not be possible to impart desired physical properties. On the other hand, if the content of the modified polyolefin (B) exceeds 40% by weight, the effect corresponding to the blending amount is small, and the various properties of the obtained resin composition may be deteriorated. Further, if the content of the polypropylene resin (C) is less than 20% by weight, it is impossible to impart the original properties of polypropylene to the composition. On the other hand, if it exceeds 60% by weight, the desired effect of improving the paintability is not sufficiently exhibited.

The resin composition of the present invention contains the above-mentioned three components (A), (B) and (C) as the main components, but other additives may be added, if necessary, within a range that does not impair the characteristics of the components. You may add. Additives that can be blended here include dyes,
Examples thereof include pigments, fillers, nucleating agents, fibrous substances, plasticizers, lubricants, release agents, coupling agents, foaming agents, heat-resistant agents, weather-resistant agents, flame retardants, antistatic agents, sliding agents and the like.

The resin composition of the present invention is a resin composition prepared by blending the above three components and a predetermined amount of an additive to be added if necessary.
The order of compounding is not particularly limited, and the components may be compounded sequentially or simultaneously. Further, the powdery or pelletized component (A) after the completion of the polymerization reaction may be added to the components (B) and (C).
You may mix a component.

The resin composition of the present invention is prepared by mixing or kneading the respective components in the above-mentioned mixing ratio, and as a method therefor, a conventionally known melt-kneading method is preferable. Mixing is performed using a Banbury mixer, a Henschel mixer, etc., and as a kneading machine, a single-screw or twin-screw extruder is generally used. The temperature at the time of melt-kneading may be appropriately selected depending on the components, the blending amount, etc., so that the melting of each component does not proceed sufficiently and does not decompose. Usually 180-350 ° C, preferably
It is selected in the range of 200-300 ℃.

The obtained resin composition may be molded into an arbitrary shape by extrusion molding, compression molding, injection molding or the like to obtain a desired resin product such as a pipe or a tube. Furthermore, after that, processing such as plating and painting can be performed.

〔Example〕

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

The various physical properties of the polyamide / polyolefin resin compositions obtained in the following examples are measured based on the following test methods.

Method for preparing flat plate for coating (100 × 100 × 3 mm thickness) The flat plate was formed by molding the composition with a screw in-line injection molding machine. The cylinder temperature at this time was 280 ° C. regardless of the type of the (A) polyamide resin. The mold temperature was 60 ° C.

Melt viscosity Using a Capillograph manufactured by Toyo Seiki Co., Ltd., set temperature 28
The melt viscosity was measured at 0 ° C and a shear rate of 3500 sec ^-1 .

Paintability A two-component polyurethane resin paint (Stron Ace # 680, manufactured by Cashew Co., Ltd.) was used as a paint, and spray-applied to a flat plate, and the drying condition was 100 ° C. for 40 minutes. After the sample was left at room temperature for one day, cross-cut peeling test and adhesion strength of the coating film were measured.

Examples 1 to 9 and Comparative Examples 1 to 4 (A) polyamide resin, (B) modified polyolefin and (C) polypropylene resin shown in Table 1 were blended in predetermined amounts, and dry blended for 5 minutes with a Henschel mixer.
The mixture obtained was ventilated in the same direction twin-screw extruder (inner diameter 30 m
m, L / D = 17) and melt-kneaded to prepare pellets.
The heating temperature at the time of pellet formation was also 280 ° C.

After heating and drying these pellets under reduced pressure, a flat plate was formed by injection molding and a coating test was conducted. The results are shown in Table 1.

In addition, Table 1 also shows η _PP / η _PA at 280 ° C. and a shear rate of 3500 sec ⁻¹ .

[Effects of the Invention] As described above, according to the present invention, it is possible to produce various reinforced polyamide-polypropylene resin compositions having excellent properties of both polyamide and polypropylene, and particularly excellent in coatability. It is possible to easily obtain a resin composition suitable for applications requiring paintability.

Therefore, the polyamide / polyolefin resin composition of the present invention is suitably used for automobile parts (outer plates, exteriors, etc.), machine parts, industrial parts, etc., which are required to have coatability.

Claims (1)

(57) [Claims] 1. (A) Polyamide resin 80 to 40% by weight (excluding 40% by weight), (B) Modified polyolefin 1
~ 40 wt% and (C) Polypropylene resin 20-60 wt%
And the melt viscosity η _PA (pois of the above-mentioned (A) polyamide resin at a molding processing temperature and a shear rate of 3500 sec ⁻¹ .
e) and (C) Polypropylene resin melt viscosity η _PP (pois
A polyamide / polyolefin resin composition characterized in that the ratio of e) satisfies the formula η _PP / η _PA > 0.75 ... [I].