JPH06184433A - Polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in gloss, heat resistance and low absorptivity, useful for industrial parts,, etc., by incorporating a blend resin composition consisting mainly of a polyamide resin with a specific long chain multibranched fatty acid at specified proportion. CONSTITUTION:This resin composition can be obtained by incorporating (A) a total of 100 pts.wt. of a blend resin composition comprising (1) 90-40 (pref. 80-50) wt.% of a polyamide resin such as nylon 6, (2) 0.5-20 (pref. 3-15) wt.% of a modified polypropylene resin and (3) 9.5-40 (pref. 15-30) wt.% of a polypropylene resin with (B) 0.1-10 (pref. 0.5-5) wt.% of a long chain multibranched fatty acid and/or a salt thereof (pref. sodium salt).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide resin composition, and more particularly to a polyamide / polypropylene resin composition having both excellent characteristics of a polyamide resin and a polypropylene resin and having a good surface gloss.

[0002]

2. Description of the Related Art Generally, polyamide resins are widely used as synthetic fibers and the like because they are excellent in physical and chemical properties, but in recent years, they have also been used as molding materials. This is because the polyamide resin is in the thermoplastic resin, it has high mechanical strength, excellent abrasion resistance, chemical resistance, heat resistance, etc. as an engineering plastic, and has a good moldability. Because it is relatively good. However, on the other hand, on the other hand, an amide group (-CONH
-) Has unfavorable properties such as a dimensional change due to water absorption and a decrease in mechanical strength, which limits its marketability as a molding material. On the other hand, polypropylene resin is inexpensive, exhibits almost no water absorption, and has good moldability, but has drawbacks such as poor mechanical strength and heat resistance. Therefore, in order to improve the respective drawbacks of the polyamide resin and the polypropylene resin, it is possible to use these resins together, but in the resin composition obtained by mixing and kneading the polyamide resin and the polypropylene resin by a usual method. The compatibility is poor, and it 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, excellent abrasion resistance of polyamide resin,
For the purpose of obtaining a resin composition having electrical characteristics, heat resistance, mechanical strength, oil resistance, and low water absorption, hot water resistance, metal halide resistance, and low temperature impact resistance of polypropylene resin, a polyamide resin, It has already been reported that an olefin polymer and a modified polyolefin grafted with an unsaturated carboxylic acid or a derivative thereof are melt-mixed to obtain a composition having an excellent balance of strength, heat distortion resistance, appearance and molding processability. Japanese Patent Publication No. 42-12546, Japanese Patent Publication No. 45-30945, and Japanese Patent Publication No. 50-7636. Further, by utilizing such excellent properties, practical application is considered for some applications such as automobile parts, electric products, mechanical parts, industrial parts, etc., which require strength and heat distortion resistance, or some of them are put into practical use. ing. However, even a resin composition (polymer alloy composition) having such characteristics has a problem that the surface characteristics of the product, particularly the gloss, are still insufficient, and the appearance is inferior to that of the polyamide resin composition, so The current situation is that there are restrictions.

[0004]

DISCLOSURE OF THE INVENTION The present invention is mainly aimed at improving the surface characteristics of a polyamide resin, especially a resin composition with polypropylene, and is excellent in glossiness, heat resistance, low absorption and the like. Another object is to provide a resin composition.

[0005]

Means for Solving the Problems The present inventors have extensively studied a method for improving gloss while maintaining excellent properties of polyamide resin and polypropylene resin. As a result, the following general formula (1) It was found that a high-gloss molded product can be obtained by adding a specific amount of the long-chain hyperbranched fatty acid and / or its salt shown, and the present invention has been completed.

That is, the present invention provides a mixed resin composition comprising a polyamide resin 90 to 40% by weight, a modified polypropylene resin 0.5 to 20% by weight, and a polypropylene resin 9.5 to 40% by weight, based on 100 parts by weight in total. Then, the following general formula (1)

[Chemical 2] (In the formula, R ¹ and R ² represent an alkyl group having 4 to 14 carbon atoms, m represents an integer of 1 to 4, and p and q are the total number of carbon atoms in the long-chain multibranched fatty acid molecule. The present invention relates to a polyamide resin composition characterized by containing 0.1 to 10 parts by weight of a long-chain hyperbranched fatty acid represented by the formula 20 to 60) and / or a salt thereof.

Various types of polyamide resins can be used in the present invention. Specifically, polylactams such as nylon 6, nylon 11 and nylon 12, nylon 6 are used.
Polyamides obtained from dicarboxylic acids and diamines such as 6, nylon 610, nylon 612, nylon 46, nylon 6/66, nylon 6/12, nylon 6
Copolymerized polyamides such as / 66/610, nylon 6 /
6T (T: terephthalic acid component), semi-aromatic polyamides obtained from aromatic dicarboxylic acids such as isophthalic acid and metaxylene diamine or aliphatic diamine, polyester amides, polyether amides, polyester ether amides, and the like. it can. As the polyamide resin component, the above various polyamide resins may be used alone or in combination of two or more kinds.

Further, the polyamide resin that can be used in the present invention is not limited to the type, concentration and molecular weight of the terminal groups of these polyamide resins, so long as it is selected from the above-mentioned polyamide resins. Can be used, but high amino terminated polyamide resins are especially preferred. It is also possible to use a polyamide resin in which low molecular weight components such as monomers and oligomers that remain or are formed during polymerization of the polyamide resin are mixed. The polyamide resin in the mixed resin composition comprising a polyamide resin, a modified polypropylene resin and a polypropylene resin is required to be 90 to 40% by weight, and preferably 80 to
It is 50% by weight. If it exceeds 90% by weight, the absorbency becomes poor, and if it is less than 40% by weight, the heat resistance becomes insufficient.

Although various types of modified polypropylene resins can be used in the present invention, usually, carboxylic acid groups (acetic acid group, acrylic group, methacrylic acid group, fumaric acid group, itaconic acid group, etc.), acid anhydrides It has at least one functional group selected from a group (such as a maleic anhydride group) or an epoxy group.

Specific examples of such modified polypropylene resin include copolymers obtained by grafting the above-mentioned functional groups onto polypropylene, for example, maleic anhydride graft modified polypropylene. These modified polypropylene resins may be used alone or in combination of two or more. Further, the modified polypropylene resin includes not only a modified product of a propylene homopolymer but also a modified product of a copolymer with another comonomer such as ethylene. The modified polypropylene resin in the resin composition comprising the polyamide resin, the modified polypropylene resin and the polypropylene resin is 0.5 to 20% by weight, preferably 3 to 15% by weight. If it is less than 0.5% by weight, it is difficult to improve the compatibility, and as a result, desired properties may not be imparted to the resulting composition. On the other hand, if it exceeds 20% by weight, the viscosity of the composition upon melting may increase and molding may not be possible in some cases.

The polypropylene resin in the present invention is generally used for molding materials, for example, polypropylene homopolymer, random or block copolymer of propylene and ethylene and / or α-olefin,
For example, ethylene-propylene random copolymer, ethylene-propylene block copolymer and the like can be used. In addition, this polypropylene resin may be used alone or in combination of two or more. When an ethylene-propylene random copolymer is used, the ethylene content is preferably 5% by weight or less, and when the ethylene content is more than 5% by weight, it is difficult to obtain the effect of improving gloss. When an ethylene-propylene block copolymer is used, the ethylene content is 10
It is preferably not more than 10% by weight, and when the amount is more than 10% by weight, the gloss of the obtained molded article is insufficient. The polypropylene resin in the resin composition consisting of polyamide resin, modified polypropylene resin and polypropylene resin is 9.
5 to 40% by weight is necessary, and 15 to 30% by weight is preferable. If it is less than 9.5% by weight, low absorbency cannot be imparted. On the contrary, if it exceeds 40% by weight, the desired heat resistance cannot be obtained.

The long-chain hyperbranched fatty acid represented by the above general formula (1) used in the present invention is, for example, JP-A-3-2397.
It can be produced by the method shown in No. 43. Salts of long-chain hyperbranched fatty acids include alkali metals (for example,
Sodium, potassium, etc.), alkaline earth metals (eg, magnesium, calcium, etc.), as well as metals used in general metal soaps, namely, aluminum, zinc, copper,
Salts of lead, cobalt, nickel, iron, manganese, tin, etc. can be used. Preferred salts include salts of sodium, potassium, magnesium, calcium, aluminum and the like. The addition amount of the long-chain hyperbranched fatty acid (1) and / or its salt is 0.1 to 1 with respect to 100 parts by weight of the resin composition.
It is 0 part by weight, preferably 0.5 to 5 parts by weight.
If the added amount of the long-chain hyperbranched fatty acid (1) and / or its salt is less than 0.1 part by weight with respect to 100 parts by weight of the resin, the effect of improving surface gloss is poor, and if it exceeds 10 parts by weight, the composition is molded. In this case, the measurement becomes unstable, it becomes difficult to obtain a molded product having a constant weight, the moldability is deteriorated, and the rigidity and heat resistance of the resulting composition are deteriorated, so that desired physical properties may not be imparted.

The polyamide resin composition of the present invention may contain various additives in addition to the above-mentioned components, if necessary. For example, an antioxidant, a flame retardant,
Additives such as ultraviolet absorbers, lubricants, release agents, colorants, dispersants and the like can be added. These additives may be added simultaneously with the mixing and kneading of the above-mentioned essential components or separately. Further, the addition amount is preferably an amount that does not impair the mechanical properties, surface appearance, etc. of the molded product of the composition.

The polyamide resin composition of the present invention comprises the above-mentioned polyamide resin component, modified polypropylene resin component,
It can be obtained by uniformly mixing and kneading the polypropylene resin component, the long-chain hyperbranched fatty acid and / or its salt, and if necessary various additives in a predetermined mixing ratio. The order of compounding is not particularly limited, and the components may be compounded sequentially or simultaneously. Further, various methods can be used as a mixing / kneading method, for example, after dry blending using a mixer such as a super mixer or a Henschel mixer, a Banbury mixer, a kneader, a roll mill, or a screw type extruder. Examples of the method include kneading using a kneading machine such as the above to obtain a uniform composition.

The polyamide resin composition thus obtained according to the present invention is shaped by extrusion molding, injection molding, compression molding or the like. The molding is performed at a temperature equal to or higher than the melting point of the polyamide resin composition and equal to or lower than the temperature at which the polyamide resin composition deteriorates, but generally 180 to 350 ° C., preferably 20.
It is performed in the range of 0 to 300 ° C. Further, the shape of the molded body is not particularly limited, and it can be molded into any shape. The polyamide / polypropylene resin composition thus obtained has excellent gloss and can be effectively used as various external parts.

[0016]

The present invention will be described in more detail with reference to the following examples, which should not be construed as limiting the present invention.

Synthesis of Long-Chain Multibranched Fatty Acid Salt Into a 1-liter four-necked flask equipped with a stirrer, nitrogen gas blowing pipe, thermometer, dropping device, separator with cooling pipe, 400 g of capric acid was charged, and 190 ° C. The temperature was raised to. On the other hand, 1
33.9 g of ditertiary butyl peroxide (DTBPO) was dissolved in 143.2 g of octene, and this was added dropwise to the above four-necked flask over 2 hours. After completion of dropping, the mixture was aged for 15 minutes. Then, the pressure was gradually reduced at a temperature of 170 ° C., and vacuum distillation was performed at 100 mmHg for 2 hours to remove unreacted 1-octene. Further, the pressure reduction degree was gradually increased to 10 mmHg after 1 hour to remove unreacted fatty acids. Further, the degree of pressure reduction is increased to 5 to 4 mmHg, and the temperature is set to 2
154.3 g of 1-octene 1-mol adduct (long-chain multi-branched fatty acid having a total carbon number of 18) by distillation at 00 to 270 ° C.,
And 74.1 g of distillation residue were obtained. The composition of the residue was analyzed by gas chromatography to find that 48% of the 2-mol adduct of 1-octene was 33% of the 3-mol adduct.
%, 4 mol adduct 15%, 5 mol adduct 4%. Further, 84.1 g of a 10% sodium hydroxide solution was added to 100 g of the residue and mixed. Next, this was heated to 100 ° C., refluxed for 1 hour to carry out a neutralization reaction, and vacuum dehydration was performed under the conditions of 100 to 120 ° C. and 10 to 30 mmHg. Then, the mixture was cooled to room temperature to obtain 103.5 g of sodium salt, which was used in the following Comparative Examples and Examples.

The evaluation methods used in the examples and comparative examples are as follows. Glossiness According to ASTM-D-2457. The incident angle was 60 °. Heat distortion temperature It complied with ASTM-D-648. Water absorption rate Based on ASTM-D-570.

(Examples 1 to 7 and Comparative Examples 1 to 6) In Examples and Comparative Examples, a predetermined amount of a polyamide resin component, a modified polypropylene resin component, a polypropylene resin component and a long-chain hyperbranched fatty acid and / or a salt thereof is blended. Then, dry blending was performed for 3 minutes using a super mixer. The obtained mixture was melt-kneaded at a temperature of 280 ° C. using a twin-screw extruder (caliber: 30 mm) to produce pellets.
After heating and drying the pellets under reduced pressure, a sheet having a thickness of 1.0 mm was formed by a sheet forming machine (using a mirror surface chill roll), and the glossiness was measured. Further, a test piece was prepared by hot pressing and the heat distortion temperature was measured. The water absorption rate was measured using pellets. The results are shown in Table 1.

[0020]

[Table 1]

* 1: Shown in parts by weight based on 100 parts by weight of the mixed resin composition. * 2: Due to unstable measurement, a good product could not be molded and measurement was impossible. (1) Nylon 66 having an amino terminal group concentration of 4.8 × 10 ⁻⁵ equivalent (2) Nylon 6 having an amino group terminal concentration of 4.2 × 10 ⁻⁵ equivalent (3) Polypropylene having an MFR of 0.95 g / 10 min Graft-modified polypropylene obtained by adding 0.35% by weight of maleic anhydride to a homopolymer (4) Polypropylene homopolymer having MFR of 1.1 g / 10 minutes (5) MFR of 1.0 g / 10 minutes, ethylene Propylene block copolymer having a content of 5% by weight (6) Long-chain multibranched fatty acid salt synthesized by the method shown in the above-mentioned synthesis example

[0022]

By using the polyamide resin composition according to the present invention, it is possible to easily obtain a product which has the advantages of both polyamide and polypropylene and has an excellent appearance and a good gloss. It is preferably used in the fields of automobile parts, electric equipment parts, electronic equipment parts, and other industrial parts.

Claims (1)

[Claims] 1. A polyamide resin 90 to 40% by weight, a modified polypropylene resin 0.5 to 20% by weight, and a mixed resin composition consisting of 9.5 to 40% by weight of a polypropylene resin. General formula (1) (In the formula, R ¹ and R ² represent an alkyl group having 4 to 14 carbon atoms, m represents an integer of 1 to 4, and p and q are the total number of carbon atoms in the long-chain multibranched fatty acid molecule. A long-chain hyperbranched fatty acid represented by the formula 20 to 60) and / or a salt thereof is contained in an amount of 0.1 to 10 parts by weight.