JP3277553B2 - Polyamide / polypropylene resin reinforced composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide / polypropylene resin composition, and more particularly, to a resin composition having excellent appearance and low water absorption properties as a structural material. The present invention relates to a polyamide / polypropylene resin reinforced composition suitable as the above.

[0002]

2. Description of the Related Art Polyamide resins have excellent strength, rigidity, heat resistance and the like, and are widely used as engineering plastics in various applications.

[0003] In recent years, polyamide resins have been used as structural part materials by taking advantage of their excellent properties, their reinforcing effect when reinforced with an inorganic filler such as glass fiber and the like, and their excellent coloring and molding properties. It has become. The structural material is, for example, a material used for a structural part exposed to a relatively large stress such as a chair leg, a desk leg, a bicycle wheel rim and the like, and is conventionally a metal material. Was used.

[0004] Performances commonly required for structural material include high strength rigidity, good appearance and dimensional stability.
Recently, nylon 6, nylon 66, nylon 66 /
6 copolymers and the like are used.

However, in general, polyamide resins have high water absorption, and the water absorption causes deterioration of physical properties and dimensional change. For this reason, in an actual use atmosphere, structural parts using nylon 6, nylon 66 and nylon 66/6 copolymer, whose strength and rigidity and dimensions are greatly affected by temperature and humidity, must be designed in consideration of the reduction in strength and rigidity. There is a disadvantage that the structure is necessary and the structure becomes large.

To increase the strength and rigidity of the polyamide resin, there is a method of increasing the compounding amount of the inorganic filler. However, when this method is employed, the appearance of the surface of the molded product deteriorates conversely (for example, a whitening phenomenon due to the lifting of glass fibers, etc.). ) Since the commercial value is lost, the amount of the inorganic filler is limited.

[0007] Also, the problem due to the dimensional change of the polyamide resin is that it causes warpage and the like, and when caulking with a metal screw or the like, a screw hole is displaced or the size when joining the resins is reduced. The displacement was large, such as the clearance could not be obtained.

As a material corresponding to such an application, a method of blending a polypropylene modified with an α, β-unsaturated carboxylic acid with a polyamide resin (JP-A-60-170665)
No.) etc. are known. Certainly, the effect of improving the water absorption, impact resistance, chemical resistance, etc. is remarkable by the introduction of the polypropylene component, but if inorganic fillers such as glass fiber are blended for reinforcement, the purpose is to improve the mixing of the polyamide resin and the polypropylene resin. Due to the interaction caused by the reaction between the used admixture and the polyamide and the terminal group of the polyamide, there is a drawback that the appearance, particularly the grain transferability, is worse than when the inorganic filler is simply added to the polyamide.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the problem of a resin composition comprising a polyamide resin and a polypropylene resin which has been used as a material for a resin structure, that is, to have a low water absorption under actual use. Further, an object of the present invention is to provide a structural member having good appearance of a molded product, particularly, good grain transferability.

[0010]

SUMMARY OF THE INVENTION The present invention achieves the above object, and its gist is as follows.

The present invention relates to (A) 20 to 95% by weight of hexamethylene adipamide units obtained from adipic acid and hexamethylene diamine 0 to 40% by weight of hexamethylene terephthalamide units obtained from terephthalic acid and hexamethylene diamine (B) (I) an α, β-unsaturated polyamide resin comprising 60 to 90% by weight of a semi-aromatic polyamide resin composed of 5 to 40% by weight of hexamethylene isophthalamide units obtained from isophthalic acid and hexamethylene diamine; 100% by weight of a polyamide / polypropylene resin comprising 10 to 100% by weight of a modified polypropylene resin grafted with a carboxylic acid or a derivative thereof and 10 to 40% by weight of a polypropylene resin comprising (II) 0 to 90% by weight of an unmodified polypropylene resin. (C) Glass fiber, carbon fiber Mica, talc, kaolin, wollastonite, calcium carbonate, at least one inorganic filler selected from among potassium titanate 2
A polyamide / polypropylene resin reinforced composition comprising 0 to 250 parts by weight.

Hereinafter, the contents of the present invention will be described in detail.

The semi-aromatic polyamide resin used in the present invention is a hexamethylene adipamide unit (hereinafter referred to as N66) obtained from adipic acid and hexamethylene diamine.
Hexamethylene terephthalamide units obtained from terephthalic acid and hexamethylene diamine (hereinafter referred to as N6T) and hexamethylene isophthalamide units obtained from isophthalic acid and hexamethylene diamine (hereinafter referred to as N6I)
).

The composition ratio of each component is 20 to 95% by weight of N66, 0 to 40% by weight of N6T, and 5 to 40% by weight of N6I. A preferred composition ratio is 25 to 90% by weight of N66, 0 to 37% by weight of N6T, and 10 to 35% by weight of N6I. Further, the relative viscosity of sulfuric acid is preferably in the range of 1.5 to 3.5.

If the content of N6T is more than 40% by weight, the solidification temperature of the resin becomes high, so that the surface of the molded product becomes extremely poor due to the floating of the inorganic filler.

If N6I is more than 40% by weight, the crystallinity is greatly reduced, so that the cooling time in the mold at the time of molding is prolonged, and the productivity is deteriorated. Further, it cannot be used for applications requiring chemical resistance.

If the content of N6I is less than 5% by weight, the crystallization temperature of the resin is increased, so that the surface of the molded article is extremely poor due to the floating of the inorganic filler on the surface of the molded article. N66, N6
The copolyamide composed of each component of T and N6I is obtained by performing a polycondensation reaction from a salt of adipic acid, terephthalic acid, isophthalic acid and hexamethylenediamine. Examples include solution polymerization and interfacial polymerization.

When the content of the semi-aromatic polyamide resin component in the component (A) + (B) of the present invention is less than 60% by weight, the effect of improving the appearance of the molded product, particularly, the transfer property of the grain cannot be obtained.
On the other hand, if it is more than 90% by weight, the effect of improving the water absorption of the resin composition cannot be seen.

The polypropylene resin (B) of the present invention includes (I) 10 to 100% by weight of a modified polypropylene resin obtained by grafting an α, β-unsaturated carboxylic acid or a derivative thereof to a polypropylene resin; The modified polypropylene resin is a polypropylene resin composed of 0 to 90% by weight. The polypropylene resin used for obtaining the modified polypropylene resin is the same as the unmodified polypropylene resin of the present invention, and is a crystalline (isotactic) polypropylene resin. Is preferred. Polypropylene resin is not limited to homopolymer,
A random or block copolymer with another α-olefin containing at least mol%, preferably at least 80 mol% can be used. Comonomers copolymerized with propylene include ethylene and other α-olefins, with ethylene being preferred. Therefore, in the present specification, the “polypropylene resin” should be understood to include not only a homopolymer of propylene but also a copolymer. The MFR (melt flow ratio; ASTM D) of polypropylene resin
-1238-52D, 230 ° C, 2160 g)
The range of -80 is preferable.

The modified polypropylene resin (I) of the present invention is a polypropylene resin to which an α, β-unsaturated carboxylic acid or a derivative thereof is grafted, and the unsaturated carboxylic acid or the derivative thereof is acrylic acid or methacrylic acid. And dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid, and dicarboxylic anhydrides such as maleic anhydride and itaconic anhydride. Particularly preferred are dicarboxylic acids and anhydrides thereof. Further, the graft amount of the α, β-unsaturated carboxylic acid or a derivative thereof is as follows:
(B) The content is preferably in the range of 0.1 to 5.0% by weight based on the polypropylene resin. If the content of the modified polypropylene resin component (I) in the polypropylene resin component (B) of the present invention is less than 10% by weight, the miscibility between the polyamide resin (A) and the polypropylene resin (B) is reduced, and undesired results such as peeling are obtained. Invite.

In order to produce the modified polypropylene resin (I) used in the present invention, any of the conventionally known techniques may be used. Polypropylene resin, α, β-unsaturated carboxylic acid or its derivative, and radical generation A method in which the agents are mixed in advance and melt-mixed using an extruder, a Banbury mixer, a kneader or the like is suitably employed. As the radical generator used for the modification, any one may be used. For example, benzoyl peroxide, dicimyl peroxide, di-t-butyl peroxide, 1,1-bis (t- Butylperoxy) 3,3,5-trimethylcyclohexane, 2,5-
Dimethyldi (t-butylperoxy) hexane or the like can be used.

The inorganic filler used in the present invention is at least one inorganic filler selected from glass fiber, carbon fiber, mica, talc, kaolin, wollastonite, calcium carbonate and potassium titanate. Among them, it is preferable to mainly use glass fiber and carbon fiber. As the glass fiber, those commonly used for thermoplastic resins can be used, and there is no limitation on the fiber diameter or length, and any of chopped strand, roving, and milled fiber may be used.

The amount of the inorganic filler (C) of the present invention is as follows:
20 to 250 parts per 100 parts by weight of component (A) + (B)
Parts by weight, preferably in the range of 30 to 150 parts by weight. If the amount of the inorganic filler is less than 20 parts by weight, the reinforcing effect of the inorganic filler is not sufficient. If the amount is more than 250 parts by weight, it becomes difficult to mix the inorganic filler by melt-kneading. Further, even if it can be blended, the fluidity of the resin deteriorates, and it becomes difficult to fill the thin portion with the resin. Further, a decrease in fluidity is not preferred because the appearance of the surface of the molded article is deteriorated.

In order to produce the polyamide / polypropylene resin reinforced composition of the present invention, any of the conventionally known techniques may be used. The polyamide resin, the modified polypropylene resin and the inorganic filler are preliminarily mixed, and an extruder, a Banbury A method of melt-mixing using a mixer, a kneader, or the like, or a method of mixing a polyamide resin and a modified polypropylene resin in advance and side-feeding the inorganic filler from the hopper of the extruder while feeding the inorganic filler midway is preferably used.

According to the present invention, when a polypropylene resin and a polyamide resin are blended and reinforced with an inorganic filler, the composition ratio of the aromatic polyamide is 20 to 9 as described above.
5 wt%, N6 T from 0 to 40 weight%, N6I 5 to 40
By setting the content in the range of% by weight, it is possible to improve the appearance of the molded product which could not be achieved by the prior art, and furthermore, it is characterized that the physical properties at the time of absorbing water are remarkably improved.

In the present invention, a thermoplastic resin other than the polyamide resin and the polypropylene resin may be mixed for the purpose of improving the physical properties. As the thermoplastic resin, styrene-butadiene copolymer and hydrogenated product, ethylene-α-
Thermoplastic elastomers such as olefin-diene copolymers, or their α, β-unsaturated carboxylic acids, or derivatives or grafts or copolymers thereof, polyphenylene ether, polyether, polyester, polyarylene sulfide, polysulfone, Polycarbonate, polyamide imide and the like can be mentioned.

In the resin composition of the present invention, an antioxidant, a heat stabilizer, an ultraviolet absorber, a dye, a pigment, a plasticizer, a lubricant, a flame retardant, a nucleator, which are added to a usual thermoplastic resin as required. The addition of various additives such as agents is not particularly limited.

[0028]

【Example】

Evaluation method Evaluation of the test pieces molded in the following examples and comparative examples is as follows.

Absorption rate: 23 ° C. for each molded product
After immersion for 24 hours, measurement was performed using a coulometric titration moisture analyzer (manufactured by Mitsubishi Kasei Corporation: Model CA-06).

[0030] Tensile strength: Performed according to ASTM638.

Flexural modulus: Performed according to ASTM790.

Lifting of inorganic filler: The presence or absence of lifting of the inorganic filler on the surface of the molded article was visually judged.

Grain transferability: Molding was performed with a mold with a grain, and good or bad transfer was visually judged.

Production Example 1 Equimolar salt of adipic acid and hexamethylenediamine 1.2
5 kg, equimolar salt of terephthalic acid and hexamethylenediamine 0.75 kg, equimolar salt of isophthalic acid and hexamethylenediamine 0.50 kg and pure water 2.5 kg
Into the L autoclave and stirred well. Enough N
After _{disubstituted,} the temperature was raised over a period of about 1 hour to 220 ° C. from room temperature with stirring. At this time, the internal pressure becomes 18 kg / cm ² -G due to the natural pressure of the steam in the autoclave, but the heating was further continued while removing water outside the reaction system so as not to reach a pressure of 18 kg / cm ² -G or more. .
After another 2 hours, when the internal temperature reached 260 ° C., the heating was stopped, the discharge valve of the autoclave was closed, and the mixture was cooled to room temperature over about 8 hours. After cooling, open the autoclave,
About 2 kg of the polymer was removed and ground. The obtained pulverized polymer is placed in a 10 L evaporator under a stream of N ₂ ,
Solid phase polymerization was performed at 200 ° C. for 10 hours. Relative viscosity of sulfuric acid (ηr: 1 g of polymer / 95.5% sulfuric acid 10)
(0 ml titration at 25 ° C.) was 1.38 to 2.24. The composition is shown in Table 1. Production Example 2 Equimolar salt of adipic acid and hexamethylenediamine 2.0
Production Example 1 was repeated except that 0 kg, 0.50 kg of equimolar salt of isophthalic acid and hexamethylenediamine and 2.5 kg of pure water were used as starting materials. The composition is shown in Table 1.

Production Example 3 Equimolar salt of adipic acid and hexamethylenediamine 1.5
Production Example 1 was repeated except that 0 kg, 0.50 kg of equimolar salt of terephthalic acid and hexamethylenediamine, 0.50 kg of equimolar salt of isophthalic acid and hexamethylenediamine and 2.5 kg of pure water were used as starting materials. Table 1 shows the composition
Shown in

Production Example 4 Equimolar salt of adipic acid and hexamethylenediamine 2.2
Production Example 1 was repeated except that 5 kg, 0.25 kg of ε-caprolactam and 2.5 kg of pure water were used as starting materials. The composition is shown in Table 1.

Production Example 5 Equimolar salt of adipic acid and hexamethylenediamine 0.7
Production Example 1 was repeated except that 5 kg, equimolar salt of terephthalic acid and hexamethylenediamine, 1.25 kg of equimolar salt of isophthalic acid and hexamethylenediamine, and 0.5 kg of pure water were used as starting materials. Table 1 shows the composition
Shown in

Production Example 6 Equimolar salt of adipic acid and hexamethylenediamine 1.2
Production Example 1 was repeated except that 5 kg, equimolar salt of isophthalic acid and hexamethylenediamine (1.25 kg) and pure water (2.5 kg) were used as starting materials. The composition is shown in Table 1.

[0039]

[Table 1]

Production Method of Maleic Anhydride Grafted Polypropylene Polypropylene Resin (Asahi Kasei Polypropylene E110)
0) 10 kg, maleic anhydride [manufactured by Wako Pure Chemical Industries, Ltd.] 1
50 g, peroxide (Nippon Oil & Fat Perhexa 25B) 12
g was weighed and blended, and a cylinder set temperature of 180 ° C. and a discharge rate of 30 kg / m were extruded using a PCM45 extruder of Ikegai Iron Works Co., Ltd.
h, Vent vacuum −60 mmHg.

The resulting maleic anhydride-modified polypropylene was formed into a film having a thickness of 0.1 mm by hot pressing, the infrared absorption spectrum was measured, and the amount of maleic anhydride was quantified from the absorption peak intensity of the acid anhydride at 1780 cm ^-1 . The result was 0.58% by weight. Also, ASTM
According to D-1238-52D, 216 at 230 ° C.
The MFR measured using a load of 0 g was 63 g / 10 minutes.

Example 1 70% by weight of the polyamide resin produced in Production Example 1
And 30% by weight of maleic anhydride-modified polypropylene resin were dry-blended and melt-mixed with a 30 mm φ biaxial extruder {PCM-30 of Ikegai Iron Works Ltd .: L / D = 17} to obtain pellets. The obtained polymer and glass fiber (03JA416, manufactured by Asahi Fiberglass Co., Ltd.)
Was melt-kneaded under the following conditions using a twin-screw extruder. 2
The cylinder temperature of the screw extruder (ZSK25 manufactured by Werner) was set to 280 ° C., and the screw rotation was 100 r.
The polymer was charged from the hopper at pm. The glass fiber is obtained from ZONE4 by a resin composition {(A) + (B) component}.
The glass fiber was fed by side feed so that the blending amount of glass fiber with respect to 100 parts by weight was 100 parts by weight. The polymer charging section and the glass fiber charging section were sufficiently purged with N ₂ . Z
Vent vacuum was applied from ONE6 (650 mmHg).
The discharge rate was 9.4 kg / HR and the resin temperature was 305 ° C.
The pellets thus obtained were dried at 80 ° C. under N ₂ for 24 hours, injection-molded with an injection molding machine (PS-40E manufactured by Nissei Resin), and each test piece was prepared. Table 2 shows the results.

Example 2 70% by weight of the polyamide resin produced in Production Example 2
The procedure was performed in the same manner as in Example 1 except that 30% by weight of a maleic anhydride-modified polypropylene resin was dry-blended.
Table 2 shows the results.

Example 3 70% by weight of the polyamide resin produced in Production Example 3
The procedure was performed in the same manner as in Example 1 except that 30% by weight of a maleic anhydride-modified polypropylene resin was dry-blended.
Table 2 shows the results.

Example 4 70% by weight of the polyamide resin produced in Production Example 1
The procedure was performed in the same manner as in Example 1 except that 20% by weight of maleic anhydride-modified polypropylene resin and 10% by weight of unmodified polypropylene were dry-blended. Table 2 shows the results.

Comparative Example 1 The procedure of Example 1 was repeated except that no glass fiber was used. Table 2 shows the results.

Comparative Example 2 The amount of glass fiber was changed to the resin composition {(A) + (B) component}.
Example 1 except that the glass fiber was added by side feed so that the blending amount of glass fiber was 270 parts by weight based on 100 parts by weight.
The same was done. Table 2 shows the results.

Comparative Example 3 95% by weight of the polyamide resin produced in Production Example 1
The procedure was performed in the same manner as in Example 1 except that 5% by weight of maleic anhydride-modified polypropylene resin was dry-blended. Table 2 shows the results.

Comparative Example 4 50% by weight of the polyamide resin produced in Production Example 1
The procedure was performed in the same manner as in Example 1 except that 50% by weight of maleic anhydride-modified polypropylene resin was dry-blended.
Table 2 shows the results.

Comparative Example 5 70% by weight of the polyamide resin produced in Production Example 1
The same procedure as in Example 1 was carried out except that dry blending was performed with 30% by weight of unmodified polypropylene resin. Table 2 shows the results.

Comparative Example 6 70% by weight of the polyamide resin produced in Production Example 4
The procedure was performed in the same manner as in Example 1 except that 30% by weight of a maleic anhydride-modified polypropylene resin was dry-blended.
Table 2 shows the results.

Comparative Example 7 70% by weight of the polyamide resin produced in Production Example 5
The procedure was performed in the same manner as in Example 1 except that 30% by weight of a maleic anhydride-modified polypropylene resin was dry-blended.
Table 2 shows the results.

Comparative Example 8 70% by weight of the polyamide resin produced in Production Example 6
The procedure was performed in the same manner as in Example 1 except that 30% by weight of a maleic anhydride-modified polypropylene resin was dry-blended.
Table 2 shows the results.

[0054]

[Table 2]

[0055]

[Table 3]

[0056]

The present invention shows excellent low water absorption properties,
In addition, it is possible to provide a resin composition having a good appearance of a molded product such as excellent grain transferability, and the modified resin composition can be used not only for structural parts materials, automobile parts, electric and electronic parts, but also for a wide range of applications. Can be used.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI // (C08L 77/06 (C08L 77/06 23:26) 23:26) (56) References JP-A-4-149234 ( JP, A) JP-A-60-170665 (JP, A) JP-A-62-268851 (JP, A) JP-A-63-305148 (JP, A) JP-A-3-115458 (JP, A) JP Hei 4-146962 (JP, A) JP-A-61-200123 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 77/00-77/12 WPI (DIALOG)

Claims (1)

(57) [Claims] 1. A hexamethylene adipamide unit (A) obtained from adipic acid and hexamethylene diamine
-95% by weight; 0-40% by weight of hexamethylene terephthalamide units obtained from terephthalic acid and hexamethylene diamine; 5-40% by weight of hexamethylene isophthalamide units obtained from isophthalic acid and hexamethylene diamine. 60-90% by weight of semi-aromatic polyamide resin
And (B) 10 to 100% by weight of a modified polypropylene resin obtained by grafting (I) a polypropylene resin with an α, β-unsaturated carboxylic acid or a derivative thereof, and (II) 0 to 90% by weight of an unmodified polypropylene resin. 100 parts by weight of a polyamide / polypropylene resin comprising 10 to 40% by weight of a polypropylene resin and at least one selected from the group consisting of (C) glass fiber, carbon fiber, mica, talc, kaolin, wollastonite, calcium carbonate, and potassium titanate Inorganic filler 2
A polyamide / polypropylene resin reinforced composition comprising 0 to 250 parts by weight.