KR20100028161A - High impact polyamide resin composition and method thereof - Google Patents

Abstract

PURPOSE: A polyamide resin composition is provided to ensure excellent mechanical strength, heat resistance and workability, especially impact strength at a room temperature and low temperature, by comprising glass fiber and additives for strengthening interface adhesion. CONSTITUTION: A polyamide resin composition comprises (a) polyamide 50-85 weight%, (b) impact strength reinforcement 5-20 weight%, (c) additives for strengthening interface adhesion 0.05-10 weight%, and (d) glass fiber 10-30 weight%. The polyamide is a mixture of nylon 6, nylon 66 or their mixture. The impact strength reinforcement is at least one kind selected from the group consisting of ethylene-propylene rubber, ethylene-octene rubber and ethylene-propylene-diene rubber.

Description

Polyamide resin composition excellent in impact strength and its manufacturing method {HIGH IMPACT POLYAMIDE RESIN COMPOSITION AND METHOD THEREOF}

The present invention relates to a polyamide resin composition having excellent impact strength, and more particularly, including mechanically improved glass fiber and additives for interfacial adhesion, and excellent mechanical strength, heat resistance and workability, and particularly excellent impact strength at room temperature and low temperature. The present invention relates to a polyamide resin composition suitable for automobile, electric / electronic, industrial and leisure parts, and a manufacturing method thereof.

Polyamide resin is a crystalline resin, sometimes called nylon, and is used in automobile parts, fashion, building materials, electrical / electronic parts, etc. because of its excellent mechanical properties, chemical resistance and heat resistance. However, due to the water absorption due to the amide bonds, there is a problem that the impact resistance is lowered depending on the use environment, in particular, there is a limit to apply to automotive parts requiring impact resistance and the like.

As a representative method for improving the impact resistance of the conventional polyamide resin, there was a method of mixing an inorganic material such as an impact modifier or glass fibers in the polyamide resin.

U.S. Pat.No.4803247 discloses a method of mixing nitrile rubber as an impact modifier, and polyolefin rubber grafted with maleic anhydride as an impact modifier, to a polyamide resin. There is a problem that does not satisfy or other physical properties such as heat resistance is lowered.

U.S. Patent No. 5919865 discloses a polyamide resin that includes an impact modifier and is reinforced with glass fibers, but threatens the user's safety due to the creation of sharp edges in case of damage caused by impacts, in particular glass fiber reinforced. Nylon 6 (or polyamide 6) has an impact resistance of about 5 kg · cm / cm at room temperature, and thus is not suitable for use in automotive parts such as a car door frame.

In addition, when the glass fiber is added to the polyamide resin together with the impact modifier, there is a problem that the tensile elongation and appearance characteristics are lowered as the content of the glass fiber increases.

Therefore, it is urgent to develop a polyamide resin composition which is excellent in impact strength, elongation, and appearance characteristics at both room temperature and low temperature, and does not generate sharp edges when damaged by impact.

In order to solve the problems of the prior art as described above, the present invention is excellent in mechanical strength, heat resistance and workability, including glass fiber and additives for interfacial adhesion reinforcement, in particular excellent in impact strength at room temperature and low temperature, automotive, electrical / electronic An object of the present invention is to provide a polyamide resin composition and a method for producing the same, which are suitable for parts of industrial and leisure products.

The above and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention is a) 50 to 85% by weight of polyamide; b) 5 to 20% by weight impact modifier; c) 0.05 to 10% by weight of an additive for enhancing interfacial adhesion; And d) 10 to 30% by weight of glass fibers; provides a polyamide resin composition comprising a and a method for producing the same.

According to the present invention, it is excellent in mechanical strength, heat resistance and workability including glass fiber and interfacial adhesion reinforcing additives, and particularly excellent in impact strength at room temperature and low temperature, and suitable for parts of automobiles, electrical / electronics, industrial materials and leisure products. There is an effect of providing a polyamide resin composition and its preparation method.

Hereinafter, the present invention will be described in detail.

The polyamide resin composition of the present invention comprises a) 50 to 85% by weight of polyamide; b) 5 to 20% by weight impact modifier; c) 0.05 to 10% by weight of an additive for enhancing interfacial adhesion; And d) 10 to 30% by weight of glass fibers.

The polyamide is not particularly limited, but may be polyamide prepared by condensation polymerization of lactam or ω-amino acid alone or two or more, or polyamide prepared by condensation polymerization of diacid and diamine. May be nylon 6, nylon 66, or the like.

In addition, the polyamide may be homopolyamide, copolyamide or a mixture thereof, and may be crystalline, semicrystalline or amorphous.

The impact modifier is not particularly limited, but may be preferably at least one selected from the group consisting of ethylene-propylene rubber, ethylene-octene rubber, ethylene-propylene-diene rubber, and the like, based on the total content of the polyamide resin composition. It may be included in an amount of 20 to 20% by weight, preferably 7 to 13% by weight, but when included in less than 5% by weight impact strength is somewhat improved but not enough impact resistance is expressed and a sharp edge when broken by impact (sharp edge) is generated, when included in more than 20% by weight impact strength is greatly improved, and there is a problem that the injection molding processability and the like is inferior. In order to effectively improve impact resistance properties, the impact strength can be effectively improved only by using an impact modifier grafted with a maleic anhydride group capable of reacting with a polyamide resin, rather than a general impact modifier.

The additive for enhancing interfacial adhesion is to increase the interfacial adhesion between the polyamide resin and the glass fiber and is a coupling agent for strengthening the bond between the organic material and the inorganic material having a hydrolyzable group and an organic functional group in the molecule. Depending on the form of the organic functional group may be an amino group (vinyl group), vinyl (vinyl), methacryl (methacryl) group, isocyanate group, epoxy group, etc., preferably may be an amino group, isocyanate group, etc. It may be included in the amount of 0.05 to 10% by weight relative to the total content of the polyamide resin composition, there is an effect of improving the strength through strengthening the excellent interfacial adhesion within this range. Compared to the case of using only amino silane-coated species on the glass fiber, the use of an interfacial adhesion enhancer with a small amount of amino and isocyanate groups improves impact strength and sharp edges compared to using GF alone. It can bring further improvement to the problem of edge).

The glass fiber is not particularly limited, but is preferably a class coated with amino silane, and preferably has a filament diameter of 10.0 to 13 μm and a strand length of 3 to 4 mm. The impact characteristic is excellent in the range.

The polyamide resin composition may be selected from the group consisting of various stabilizers, lubricants, mold release agents, pigments, dyes, flame retardants, reinforcing agents, antioxidants, antistatic agents, conductive additives, EMI shielding agents, nucleating agents, antibacterial agents, deodorants, lubricants, and the like, as necessary. The selected one or more may further include within a range that does not affect the physical properties, appearance, formability.

For reference, when glass fiber is added to the polyamide resin together with the impact modifier, the tensile elongation and appearance characteristics decrease when the glass fiber content is increased, and there are problems such as sharp edges when the molded product is damaged. The polyamide resin composition of the present invention comprises 5 to 20% by weight of impact modifiers and 10 to 30% by weight of glass fibers, while mechanical stiffness, heat resistance, appearance characteristics, and the like compared to polyamide resin compositions reinforced with conventional glass fibers. It was further improved, especially at both impact and low temperature (-30 ° C.) in impact resistance.

Method for producing a polyamide resin composition of the present invention comprises a) 50 to 85% by weight of polyamide; b) 5 to 20% by weight impact modifier; c) 0.05 to 10% by weight of an additive for enhancing interfacial adhesion; And d) 10 to 30% by weight of glass fibers; melt kneading at a barrel temperature of 250 to 330 ° C. and a kneading speed of 200 to 350 rpm.

The extruder is not particularly limited as long as it can be used for kneading of polyamide resin and glass fiber, and may be a twin screw extruder. As a specific example, a polyamide, an impact modifier, an interfacial adhesion enhancer, an antioxidant, and the like may be added to a main hopper. In this case, the glass fiber can be kneaded by feeding the side feeder to the side feeder.

Preferably, the barrel temperature is 250 to 330 ° C., and the kneading speed is preferably 200 to 350 rpm. Within these ranges, the polyamide resin composition has excellent dispersion and low deterioration in glass fiber and impact modifier. Silver has excellent impact resistance and workability, and also has the effect of not having sharp edges when damaged by impact due to the implementation of an optimal morphology.

The polyamide resin composition may be applied to parts requiring impact resistance, such as automobile interior and exterior materials, under hood, electrical / electronic, industrial materials, and leisure products, and in particular, such as a door frame inner cover. It can be applied to automotive parts requiring high impact resistance at both room temperature and low temperature, and requiring excellent mechanical rigidity and heat resistance.

Specific examples of automotive parts requiring high impact resistance at both room temperature and low temperature include a driver airbag mounting plate, a passenger airbag mounting plate, a fuse box, various covers, and the like.

Hereinafter, preferred examples are provided to help the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and various changes and modifications within the scope and spirit of the present invention are apparent to those skilled in the art. It is natural that such variations and modifications fall within the scope of the appended claims.

EXAMPLE

Example  1 to 8

50 to 85% by weight of nylon 6 (EN 200,300 grade, manufactured by KP) or nylon 66 (27AE grade, manufactured by Rhodia) as an amount shown in Table 1, ethylene-octene rubber (Fusabond N MN 493D grade, DuPont) as an impact modifier 5 to 20% by weight, 0.05 to 10% by weight of amino silane (A1000 series grade, manufactured by GE Toshiba) and 0.1 to 5% by weight of antioxidant (Irganox grade, manufactured by Ciba) as additives for enhancing interfacial adhesion In the main hopper of the twin-screw extruder, 10 to 30% by weight of glass fiber (T-249H grade, manufactured by NEG, 10 μm in diameter and 3 mm in length) was added to the side feeder in a content of 270 to 290 ° C. And extruding by melt kneading under the conditions of 200 to 350 rpm, and then pelletized by a pelletizer, which was dried for 6 hours in a dehumidifying dryer at 90 ℃ and finally injection molded into a specimen for measurement of physical properties

Comparative example  1 to 2

The same method as in Examples 1 to 8 was conducted except that no additive for enhancing interfacial adhesion was added.

Division (weight%) Nylon 6 Nylon 66 Ethylene-Octene Rubber Interfacial Adhesive Fiberglass Example One 85 - 5 0.5 10 2 80 - 5 1.0 15 3 75 - 10 1.0 15 4 65 - 20 1.0 15 5 - 85 5 0.5 10 6 - 80 5 1.0 15 7 - 75 10 1.0 15 8 - 65 20 1.0 15 Comparative example One 80 - 5 - 15 2 - 80 5 - 15

[Test Example]

The physical properties of the specimens prepared in Examples 1 to 8 and Comparative Examples 1 and 2 were measured by the following method, and the results are shown in Table 2 below.

Impact strength (impact resistance): measured according to ASTM D256.

* Flexural modulus: measured according to ASTM D790.

Flexural strength: measured according to ASTM D790.

Tensile strength: measured according to ASTM D638.

division Tensile Strength (kg / cm ² ) Flexural Strength (kg / cm ² ) Flexural modulus (kg / cm ² ) Room temperature impact strength kgcm / cm Low Temperature Impact Strength (-30 ℃) kgcm / cm Example 1 930 1200 36000 10.3 4.5 Example 2 1050 1400 42000 10.7 4.8 Example 3 910 1250 38000 17.1 6.0 Example 4 750 950 31000 30.0 18.2 Example 5 920 1195 36000 10.1 4.1 Example 6 1040 1350 41600 10.4 4.4 Example 7 900 1200 37600 15.7 5.5 Example 8 740 940 31000 28.3 16.8 Comparative Example 1 1010 1260 39000 9.8 3.9 Comparative Example 2 1000 1240 38000 9.7 3.7

As shown in Table 1, the polyamide resin composition (Examples 1 to 8) of the present invention is at room temperature and in comparison with the polyamide resin composition (Comparative Examples 1 and 2) that does not include an impact modifier and an additive for enhancing interfacial adhesion. It was confirmed that the low-temperature impact strength (impact resistance) is highly improved.

For reference, in the case of Examples 4 and 8 including 20% by weight of the impact modifier, the workability was slightly decreased, but the impact strength (impact resistance) was greatly increased, and the toughness was greatly improved. In Examples 1 and 2, the impact strength was slightly improved, but the mechanical stiffness was considerably increased, and in Examples 3 and 7, including 10 wt% of the impact modifier, both the mechanical strength and the impact strength were excellent. .

In addition, in Examples 1 to 4 using nylon 6, the heat resistance characteristics were lower than those of Examples 5 to 8 using nylon 66 having a high degree of crystallinity of about 10% or more. All of them were confirmed to have sufficient impact strength and mechanical rigidity to be applied to automotive parts such as door frame inner cover.

Claims (10)

a) 50 to 85 weight percent of polyamide; b) 5 to 20% by weight impact modifier; c) 0.05 to 10% by weight of an additive for enhancing interfacial adhesion; And d) 10 to 30% by weight of glass fibers; characterized in that comprises Polyamide resin composition. The method of claim 1, The polyamide is characterized in that the nylon 6, nylon 66 or a mixture thereof Polyamide resin composition. The method of claim 1, The impact modifier is at least one member selected from the group consisting of ethylene-propylene rubber, ethylene-octene rubber and ethylene-propylene-diene rubber. Polyamide resin composition. The method of claim 1, The impact modifier, characterized in that contained in 7 to 13% by weight Polyamide resin composition. The method of claim 1, The additive for strengthening the interfacial adhesion is characterized in that the additive for enhancing the silane-based and isocyanate-based interfacial adhesion. Polyamide resin composition. The method of claim 5, The additive for enhancing interfacial adhesion is at least one member selected from the group consisting of silane and isocyanate. Polyamide resin composition. The method of claim 1, The glass fiber is an aminosilane-coated glass fiber, characterized in that 10 to 13 ㎛ in diameter and 3 to 4 mm in length Polyamide resin composition. a) 50 to 85 weight percent of polyamide; b) 5 to 20% by weight impact modifier; c) 0.05 to 10% by weight of an additive for enhancing interfacial adhesion; And d) 10 to 30% by weight of glass fibers; melt kneading at a barrel temperature of 250 to 330 ° C. and a kneading speed of 200 to 350 rpm. Method for producing a polyamide resin composition. The method of claim 8, The polyamide, impact modifier, and interfacial adhesion reinforcing additives are introduced into the main hopper of the extruder, and the glass fibers are melt-kneaded by feeding into the side feeder of the extruder. Method for producing a polyamide resin composition. Automobile door frame inner cover made of the polyamide of claim 1.