KR101299068B1 - Polyamide resin composition and moldings including the same - Google Patents

Abstract

The present invention relates to a glass fiber-reinforced polyamide resin composition, and more particularly, polyamide resin, glass fiber, acid-modified rubber elastomer, acid-modified polyolefin, impact strength of at least 8 kg · cm / cm by ASTM evaluation method D256 , A polyamide resin composition having a flexural modulus of 40,000 kg / cm ² or more according to ASTM evaluation method D790, a shrinkage rate deviation of 130% or less according to Formula 1 below, and a heat deformation temperature of ASTM evaluation method D648 of 180 ° C. or more.

[Equation 1]

In addition, the molded article prepared from the polyamide resin composition of the present invention is excellent in mechanical strength such as impact strength, flexural modulus, heat deformation temperature, and the like. The instability is greatly improved, and the flow index of the molded article is excellent, and the surface defect phenomenon is improved, and it is suitable for the door frame inner cover, which is a vehicle interior part.

Inorganic materials, polyamides, thermoplastic rubber elastomers, acid-modified polyolefins, impact strength, flexural modulus, heat deformation temperature, dimensional stability. Car door frame inner cover

Description

POLYAMIDE RESIN COMPOSITION AND MOLDINGS INCLUDING THE SAME}

The present invention relates to a glass fiber reinforced polyamide resin composition, and more particularly, to a polyamide resin composition having excellent mechanical strength and excellent dimensional stability.

Recently, with the development of the automotive industry, research on plastic substitution of electric / electronic parts has been actively conducted in terms of light weight, low manufacturing cost, improved design freedom, and simplified manufacturing process. Polyamide resin in plastic has been in the spotlight as an important substitute material for such research and development, and in the case of automobiles, it has an excellent advantage as a substitute material for aluminum or steel. The door frame inner cover, which is a built-in product, is not often applied as a polyamide resin, but research is being actively applied to polyamide resin for various models due to its excellent mechanical strength, formability, and long-term physical properties.

To further improve the disadvantages of polyamide resin as a vehicle material, to provide a high-performance polyamide resin, the shrinkage anisotropy caused by the difference in molding shrinkage according to the flow direction of the resin generated during molding as well as rigidity and impact resistance There is an urgent need for significant improvements in properties. In particular, in the case of auto parts, the development of modularization or the replacement of steel or aluminum is being actively progressed rather than the development of single products. Therefore, technical elements such as large products or thin film products may be needed. The disadvantages of the resin, stiffness improvement, impact resistance improvement, and high mold shrinkage and improvement of shrinkage anisotropy are indispensable.

A widely known method for producing such a high-performance polyamide resin is a method of polymerizing polyamide resin to prepare a new resin or alloying with other polymers. In addition, the inorganic filler reinforcing technique is well known by melt extrusion kneading as a method for producing a high functional polyamide resin according to the use.

Since the technology produced by polymerization is high in time and cost, many alloy techniques with other polymers are proposed. The alloy with other polymers is mainly composed of alloys with general-purpose plastics or acid-modified rubber elastomers, The alloys of the alloy may include polypropylene-based, polystyrene-based, and olefin-based elastomers. Since these are incompatible with polyamides, functional polyamides are prepared through commercialization techniques.

In addition, in the case of inorganic filler-reinforced polyamide resin, the addition of glass fiber or mineral used as an inorganic material has been used for a long time because of the advantages of good rigidity and heat resistance and low molding shrinkage. In many applications. As a representative technique in this field, a technique for improving heat resistance and dimensional stability by reinforcing inorganic materials after alloying with other polymers has been proposed, and representative techniques established in this regard include inorganic fillers after adding polyolefin elastomer ( techniques to enhance fillers are described in US Pat. No. 5206284 or EP 1 312 647. These are proposed techniques for improving the functionality by adding an elastomer to the impact resistance failure caused by the inorganic filler reinforcement. However, the technique well described in US Pat. No. 5,206,628 or EP 1 312 647 is excellent in impact resistance or toughness due to the addition of an elastomer, but the heat resistance is deteriorated and the surface is poor in molding. Application to the use is difficult, and the addition of glass fiber alone has a disadvantage in that the dimensional stability is poor and the impact resistance is poor, there is a limit to the application of the application to automotive products.

As another technique, US Patent No. 5214091 proposes a technique of adding an inorganic filler and adding a substance having an unsaturated carboxyl group to promote compatibility. However, the carboxyl group-containing composition in addition to the inorganic filler is effective in improving compatibility, and is excellent in general physical properties and surface conditions during molding, but is restricted in forming large products or thin films with an increase in viscosity.

Other Another proposed technique is described in EP 0 117 998, which adds an inorganic filler such as glass fiber but further adds a coupling agent to enhance adhesion with the polyamide resin. In addition, this technique introduces that it has the technical ability to improve the surface defect phenomenon and strength that occur during molding as the inorganic filler is strengthened. However, this technology has been introduced to have the technical ability to improve the surface defects and strength, the addition of the coupling agent is possible to improve the surface properties and further increase the strength, but due to the addition of the coupling agent weather resistance or long-term heat resistance There is a shortcoming and there is a problem that leads to an increase in manufacturing cost.

In addition, reinforcing techniques for alloying polypropylene and adding fillers to polyphthalamide resins are described in US Pat. No. 5,229,805, EP 0 477 027. US Pat. It has also been proposed to use an olefin-based impact agent or the like and an inorganic filler to be used for extrusion if necessary. The US Patent No. 5292805 and the European Patent No. 0 477 027 have various technical elements, but the merits of the commercialization are somewhat low due to the high processing temperature and the high price of the polyphthalamide resin, and the US Patent No. 6953541 is a plasticizer. And an olefin-based impact agent, but the plasticizer has a limited surface strength due to gas generation during molding and a low strength, thereby limiting its application.

On the other hand, Japanese Patent Laid-Open No. 2006-056938 discloses a technique for providing a polyamide resin composition composed of a polyamide resin, a fibrous reinforcement material, and an inorganic filler, and having excellent fluidity and rigidity, but it is limited to overcome impact resistance and heat resistance. It can be seen that.

As described above, these conventional techniques are mostly to align the polyamide resin alone or other heterogeneous polymers, reinforce the inorganic filler, and add a coupling agent or an elastomer to improve the disadvantages of additional physical properties or defects. Most of the technical points are those that have core technical properties in addition to other polymers or additives that are added rather than intensifying inorganic fillers.

The present invention has excellent mechanical strength by adding glass fiber to polyamide resin, and greatly improves the dimensional instability caused by the difference of shrinkage ratio according to the flow direction of the resin in the product during molding, and by adding acid-modified rubber elastomer, It is an object of the present invention to provide a polyamide resin composition which has a characteristic of improving impact strength in strength, improving surface defects due to lowered fluidity and securing more excellent dimensional stability, and additionally having excellent weather resistance.

Another object of the present invention is to provide a polyamide resin molded article prepared by including the polyamide resin composition.

In order to achieve the above technical problem, the present invention provides an impact strength of 8 kg · cm / cm or more according to ASTM evaluation method D256, a flexural modulus of 40,000 kg / cm ² or more according to ASTM evaluation method D790, and a shrinkage deviation according to the following formula 1. A polyamide resin composition having a heat deflection temperature of not more than 130% and an ASTM evaluation method D648 of 180 ° C or higher.

[Equation 1]

Although the impact strength, the flexural modulus, and the heat deflection temperature of the polyamide resin composition of the present invention are larger, the smaller the shrinkage rate deviation is, the more preferable, the impact strength 8 to 20 kg · cm / cm, ASTM by ASTM evaluation method D256 It provides a polyamide resin composition having a flexural modulus of 40,000 to 90,000 kg / cm ² according to Evaluation Method D790, a shrinkage rate deviation of 110% to 130% according to Formula 1 above, and a heat deformation temperature of 180 to 245 ° C according to ASTM Evaluation Method D648. .

The present invention also relates to 50 to 80% by weight of polyamide resin, 10 to 30% by weight of glass fiber, and 5 to 15% by weight of reactive dicarboxylic acid or anhydride thereof based on 100 parts by weight of (c) polyolefin resin. 5 to 20% by weight of acid-modified polyolefin grafted with 2 to 8 parts by weight of parts and organic peroxide, and (d) acid-modified with 0.4 to 3 parts by weight of α, β-unsaturated carboxylic acid based on 100 parts by weight of rubber elastomer It provides a polyamide resin composition comprising 3 to 10% by weight of the rubber elastomer.

Furthermore, this invention provides the polyamide resin molded article containing the said polyamide resin composition.

Hereinafter, the present invention will be described in detail.

In the case of polyamide resins, the reinforcing effect of the inorganic filler is better than that of other resins. Due to these characteristics, the inorganic reinforcing technology is more diverse than other technical properties and has many technical areas. Application is the composition made by this mineral strengthening technique.

The polyamide resin composition of the present invention can also be seen in the field of such inorganic reinforcing technology, and is designed to meet the respective required characteristics in this large technical field, and the original, progressive and commercial in the field of inorganic reinforcing technology by closely examining the problems of the prior art. It has been developed to be widely used.

The present invention is based on such a polyamide resin, while reinforcing glass fibers in the inorganic filler, while significantly improving the problems of the prior art in order to satisfy both technical and application problems, and at the same time economically low production cost It is to provide a technique for producing a composition capable of molding high performance products.

More specifically, polyamide resin is used as a base resin to reinforce inorganic glass fiber to prevent stiffness, warpage and deformation, and to add a thermoplastic rubber elastomer called an impact agent to secure impact resistance. In order to minimize fluidity defects due to the addition, improve the appearance quality of the product, and to secure dimensional stability such as warpage and deformation caused by problems such as shrinkage anisotropy, an acid-modified polyolefin prepared by melt graft method is additionally added. It has been invented a composition that can achieve the purpose.

Particularly, acid-modified rubber elastomers having excellent reactivity include toughness, heat resistance, excellent addition effect, and chemical resistance while maintaining strength, heat resistance, dimensional stability, and poor impact resistance of polyamide resins. By using the to secure the impact resistance, acid-modified polyolefins to solve the problem of fluidity degradation caused by the use of the impact agent, and to further secure the dimensional stability. In addition, the technical purpose of solving this problem can be achieved by the physical properties of the surface properties and dimensional stability in the application to automotive interior parts.

In one example, the use of the polyamide resin composition of the present invention can provide a resin that is optimal for the door frame inner cover as a use suitable for wide, long and large thin film products for automotive products. In addition, the applications applicable to automotive engine parts may be suitably used for an intercooler air duct, a timing belt cover, an engine cover, a roof rack, and the like. In particular, the polyamide resin composition of the present invention is technically applicable to the door frame inner cover applications in terms of the characteristics of the use of the product with excellent properties.

The present inventors, in particular, have studied the prior art as described above. As a result, the present inventors have found that there are many limitations to the thin film and the large-size molding when the product achieves the technical purpose claimed by the present invention and commercially applied products, and overcomes the above technical problems. In order to overcome the difference in the flexural modulus, which is roughly divided into the polyamide resin, the impact strength, which is divided by the impact resistance, and the shrinkage ratio between the flow direction and the perpendicular direction generated according to the orientation of the inorganic material during molding, An acid-modified rubber elastomer and an acid-modified polyolefin are blended to achieve a desired purpose.

The polyamide resin used in the present invention is not particularly limited, but nylon 6, nylon 66, or a mixture thereof can be used. The average weight of the nylon 6, nylon 66 is preferably from 200 to 15,000 in terms of imparting excellent heat resistance and impact resistance of the final resin composition.

In one example, polyamide resins such as nylon 6 and nylon 66 may use from 50 to 80% by weight and from 52 to 77% by weight in the total composition of the present invention. Good shrinkage and anisotropy can be large, and if it is less than 80% by weight can be maintained excellent heat resistance and impact strength.

In addition, the polyamide resin of the present invention can be made in the form of chips (chip) for the final resin composition to be sufficiently dried in a dehumidifying dryer.

The polyamide resin of the present invention is not limited, but may be a relative viscosity of 2.5 to 3.5 (20 ° C, based on a solution of 1 g of polymer in 100 mL of 96% sulfuric acid). When the relative viscosity of the polyamide resin used is 2.5 or more, the rigidity and impact resistance can be maintained excellent, and when 3.5 or less, it is possible to achieve excellent state maintenance and convenience of molding on the surface of the inorganic material used with excellent fluidity.

On the other hand, the glass fiber in the polyamide resin composition of the present invention is not particularly limited because it can be used in the art, glass fiber commonly used as "G" or "K" glass (Glass) Chop) type glass fiber, which is composed of CaO · SiO ₂ · Al ₂ O ₃ , which is composed of 10 to 20% by weight of CaO, 50 to 70% by weight of SiO ₂ , and 2 to 15% by weight of Al ₂ O _3. Coupling with a silane on the glass fiber surface may be used for interfacial adhesion with the final composition. In particular, as the glass fibers used in the present invention, those having an average diameter of 10 to 13 µm and an average length of 3 to 6 mm can be used. In addition, the glass fiber in the present invention can be used in the content of 10 to 30% by weight of the total composition, 12 to 25% by weight content can be used, when used in more than 10% by weight flexural modulus is improved, 30% by weight In the case of the following, shrinkage anisotropy can be improved to a remarkable range.

Acid-modified polyolefin in the polyamide resin composition of the present invention, by using simultaneously with the polyamide in the final composition exhibits excellent fluidity, easy molding, good surface properties and further has anisotropic shrinkage characteristics is further improved, In particular, a molten graft copolymer prepared from 5 to 15 parts by weight of the reactive dicarboxylic acid or its anhydride and 2 to 8 parts by weight of the organic peroxide may be used based on 100 parts by weight of the polyolefin resin.

In the acid-modified polyolefin of the present invention, polyolefin, which is a hydrocarbon having a high molecular weight, has a low mechanical cost, has excellent mechanical properties, optical and chemical properties, and is easily used for a wide range of applications. However, general polyolefins are completely non-polar materials, so they are not compatible with other types of polymers, are incompatible with pigments, fillers, etc., and are particularly difficult to blend with other types of polymers. Therefore, by physically modifying polyolefins such as polypropylene and polyethylene in order to compensate for these disadvantages, physical properties such as improved thermal stability, increased hygroscopicity, improved dyeing property, antistatic effect and adhesion can be changed. Representative modifiers include dicarboxylic acids or anhydrides, acrylic acids or derivatives, and the graft copolymerization method may be used as the modifying method.

In the acid-modified polyolefin of the present invention, the reactive dicarboxylic acid or anhydride thereof may be selected from maleic acid, phthalic acid, itaconic acid, citraconic acid, alkenyl succinic acid, cis-1,2,3,6 tetrahydrophthalic acid, 4-methyl- 1,2,3,6 tetrahydrophthalic acid, or one or more thereof may be used as the anhydride thereof, and the organic peroxide may be benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t- Butyl peroxy) hexyn-di-t-butyl peroxide, 1,3-bis (t-butylperoxy-isopropyl) benzene, di-t-butylperoxy azelate, 2,5-dimethyl-2, 5 -Di (t-butylperoxy) hexane, t-butyl cumyl peroxide, t-butylperoxy-3,5,5-trimethylhexate, p-chlorobenzoyl peroxide, t-butyloxybenzoate, methylethyl Ketone peroxide, tris (t-butylperoxy) triazine, t-butylperoxy acetate, or t-butylperoxy isoprocarbonate Can. In addition, an acid-modified polyolefin prepared using maleic anhydride or anhydride thereof as the reactive dicarboxylic acid or anhydride thereof and benzoyl peroxide as the organic peroxide may be used.

The graft copolymer from the acid-modified polyolefin is well known solution, melt, solid phase method, as one example, in the present invention prepared by melt graft copolymerization method An acid-modified polyolefin resin can be used. As an example proposed as a method for preparing such acid-modified polyolefins, U.S. Patent No. 5,079,302 discloses the use of maleic anhydride in polyolefins at temperatures below the melting point of the polymer in the presence of a radical initiator and a catalyst such as alkenyl-substituted cyanurate or isocyanurate A method for grafting in a solid phase is disclosed. US Pat. No. 5,344,888 discloses a polypropylene system using an extruder at a high temperature of 185 ° C. or higher in the presence of a radical initiator and a catalyst such as diallyl maleate and alkenyl substituted cyanurate. A method of continuously grafting maleic anhydride on a resin is disclosed.

In one example, the polyamide resin composition of the present invention is also a polyolefin resin as a radical reactive dicarboxylic acid or acid anhydride to be grafted with a polypropylene resin (flow index 10 g / 10 min, ASTM D1238) as a base resin. The maleic acid, phthalic acid, itaconic acid, citraconic acid, alkenyl succinic acid, cis-1,2,3,6-tetrahydrophthalic acid, 4-methyl-1,2,3,6-tetrahydrophthalic acid or their Anhydride and the like, maleic acid is used in the present invention, and the amount may be used in the range of 5 to 15 parts by weight with respect to the polyolefin. If the content is 5 parts by weight or more, the graft efficiency is improved. The effect can be obtained.

In addition, another material used for the efficiency of the reaction is a radical initiator, and the radical initiator used is an organic peroxide, for example, benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5 -Di (t-butylperoxy) hexyne-di-t-butylperoxide, 1,3-bis (t-butylperoxy-isopropyl) benzene, di-t-butylperoxy azelate, 2,5- Dimethyl-2, 5-di (t-butylperoxy) hexane, t-butylcumylperoxide, t-butylperoxy-3,5,5-trimethylhexate, p-chlorobenzoylperoxide, t-butyloxy Benzoate, methyl ethyl ketone peroxide, tris (t-butylperoxy) triazine, t-butylperoxy acetate, t-butylperoxy isoprocarbonate, and the like, and the radical initiator used in the present invention is benzoyl peroxide The amount of furnace used is 2 to 8 parts by weight based on 100 parts by weight of polyolefin resin in the case of more than 2 parts by weight of initiator Superior performance of the stand and the case of less than 8 parts by weight can be obtained the results that geurapeuteuyul is improved.

The production of such acid-modified polyolefin resin can be produced by a conventional extrusion kneading machine.

In the present invention, the acid-modified polyolefin resin may be used in an amount of 5 to 20% by weight in the total composition, and may be used in an amount of 7 to 17% by weight, and when it is 5% by weight or more, the flowability of the resin is improved and is 20% by weight or less. The stiffness and heat resistance can be improved.

On the other hand, the acid-modified rubber elastomer of the present invention can be used as many known as the impact resistance or water-resistant modifier of a conventional polyamide resin, and the acid-modified rubber elastomer is 0.4 to 3 parts by weight of α, β-unsaturated carboxylic acid Can be used.

Acid-modified rubber elastomers are added as impact resistance and water resistant modifiers of polyamide resins, and include at least one unsaturated monomer such as α-olefins containing ethylene, acrylic acid and derivatives thereof, aromatic vinyl monomers, vinyl cyanide monomers, or diene monomers. The thing in which the (alpha), (beta)-unsaturated carboxylic acid was grafted to the rubber elastic body manufactured from a monomer can be used. In particular, rubber elastomers made of random or block copolymers of the aromatic vinyl monomers and vinyl cyanide monomers can be used.

The α-olefins are saturated with ethylene, propylene, butylene, 1-pentene, isobutylene, isoprene, 1-hexene, 1,3-hexadiene, 1-heptene, and vinyl acetate or propionate. Vinyl esters of carboxylic acids.

The acrylic acid and its derivatives are methacrylate, methyl acrylate, butyl acrylate, glycidyl acrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, hydryl ethyl methacrylate, amino methacrylate and glycidyl. Methacrylates or maleimide compounds such as N-phenylmaleimide, N-methylmaleimide and N-cyclohexylmaleimide.

Examples of the aromatic vinyl monomers include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, tetrabutylstyrene, dimethylstyrene, chlorostyrene, dichlorostyrene, vinylnaphthalene, and the like.

Examples of the vinyl cyanide monomers include acrylonitrile, methacrylonitrile or fumaronitrile.

The diene monomers include butadiene, 1.3-cyclohexadiene, 1,4-cyclohexadiene, cyclopentadiene, or 2,4-hexadiene.

Also, the grafted α, β-unsaturated carboxylic acids or α, β-unsaturated anhydrides and derivatives thereof are functional groups having excellent reactivity with amide groups, maleic acid, itaconic acid, citraconic acid, acrylic acid, methacrylic acid, allyl succinic acid, 2 Dicarboxylic acid, maleic acid, fumaric acid, or one or more of the anhydrides and derivatives thereof, and more specifically, maleic anhydride, itaconic anhydride, citraconic anhydride, acrylic acid, methacrylic acid, allyl succinic acid, 2-dicarboxylic acid, maleic acid, fumaric acid, diethyl maleate, dimethyl maleate, maleic anhydride, itaconic anhydride, citraconic anhydride, allyl succinic anhydride, or 4-methyl-4-cyclohexene-1 may be mentioned. .

In particular, the acid-modified rubber elastomer of the present invention is an ethylene propylene copolymer, an ethylene propylene diene copolymer, a styrene ethylene butadiene styrene (SEBS) copolymer, a styrene butadiene styrene (SBS) copolymer, or 0.4-3 parts by weight of a methacrylate butadiene styrene (MBS) copolymer and an ethylene ethyl acrylate copolymer with α, β-unsaturated carboxylic acid or α, β-unsaturated anhydride and derivatives thereof It may include. If the content is 0.4 parts by weight or more, it is excellent in compatibility with the polyamide resin, and 3 parts by weight or less prevents a high viscosity increase, thereby making kneading easier. In the present invention, ethylene octene copolymer containing ethylene containing 0.4 to 3 parts by weight of maleic anhydride in the α, β-unsaturated carboxylic acid compound may be used.

Grafting is carried out on solvents or on molten olefins in the presence of peroxides and such grafting techniques are known.

The content of the acid-modified rubber elastomer may include 3 to 10 wt% in the total composition, and may include 4 to 9 wt%. When the content of the acid-modified rubber elastomer is 3% by weight or more, the effect of improving the impact strength is remarkable, and when the amount is less than 10% by weight, heat resistance and rigidity may be improved, thereby reducing molding shrinkage and providing an excellent surface when forming a product.

In addition, there is provided a polyamide resin molded article comprising a polyamide resin composition according to the present invention, the polyamide resin molded article is used for applications such as automobile door frame inner cover, intercooler air duct, timing belt cover, engine cover, roof rack, etc. Can be used.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

 [Example]

The twin screw extruder was used for preparation of the inorganic reinforced polyamide resin composition of this invention. At this time, the cylinder barrel is prepared at a temperature of 275 ℃ to 285 ℃ (245 ℃ to 255 ℃ in the case of nylon 6), in order to maximize the physical properties of the resin composition by using an extruder having three inlet, polyamide resin and An acid-modified polyolefin resin was added, an acid-modified rubber elastomer was injected into the secondary inlet, and glass fibers were introduced into the third inlet. In particular, this tertiary inlet was used as close to the discharge part of the extruder as possible to minimize the breakage of the glass fibers due to shear of the screw in the extruder. In addition, in order to maximize the physical properties of the composition during melt kneading, the residence time is minimized, and a decompression device called vent is installed near the third inlet and outlet, and the pressure is reduced to 150 mmHg or less to perform a more effective process. It was made.

Examples and comparative examples of the present invention was carried out as follows, the composition of the resin prepared according to the evaluation of the respective physical properties based on the following evaluation criteria.

Flexural modulus: A 1/8 inch specimen was prepared according to ASTM D790, and a value less than 40,000 kg / cm ² was judged to be defective.

* Impact strength: Izod Notched impact strength was measured at room temperature with 1/4 inch specimen according to ASTM D256, and less than 8 kg · cm / cm was judged as bad.

* Shrinkage rate deviation: After fabricating 100 mm diameter specimens in accordance with ASTM D995, leaving the specimens for 48 hours at room temperature and 50% absolute humidity, and evaluating the mold shrinkage in the flow direction and the direction perpendicular to the gate. The deviation was calculated based on the following Formula 1, and was determined to be poor when the shrinkage rate deviation exceeded 130%.

[Equation 1]

* Heat deflection temperature: Measured after fabricating 1/4 inch specimen according to ASTM D648, the value less than 180 ℃ at 4.6 kg / cm ² load was determined to be defective.

Example  1 to 14

Next, each component was melt-kneaded in a twin screw extruder heated to 280 ° C (250 ° C for nylon 6) with a composition as shown in Table 1 to make a chip state, and a 90 ° C and 5 hour dehumidifying dryer was used. After drying, each specimen was produced at the same temperature as melt kneading using a heated screw-type injection molding machine. In particular, the acid-modified polyolefin resin in the polyamide resin composition has a composition as shown in Table 1 below, using a polyolefin resin, a dicarboxylic acid and an organic peroxide, to achieve a vacuum of 150 mmHg or less and five or more temperature change zones. In the twin-screw kneader, the temperature is set to 180 ° C. for the initial zone, 200 ° C. for the rest, and 205 ° C. for the last zone, and the screw rotation speed is 150 rpm. Dried at 80 ° C. for 4 hours.

Each specimen thus prepared was subjected to physical property evaluation by the evaluation method as described above, and the measurement results are shown in Table 2 below.

division Nylon 66
(weight%) Nylon 6
(weight%) glass fiber
(weight%) Acid-modified polyolefin
(weight%) Thermoplastic Rubber Elastomer
(weight%) Example 1 77 - 15 5 APO 1 3 TPE 1 Example 2 63 - 20 10 APO 1 7 TPE 2 Example 3 67 - 15 15 APO 3 3 TPE 1 Example 4 55 - 15 20 APO 2 10 TPE 2 Example 5 - 77 10 10 APO 1 3 TPE 1 Example 6 - 68 20 15 APO 3 7 TPE 2 Example 7 - 63 15 15 APO 1 7 TPE 1 Example # 8 - 55 20 15 APO 3 10 TPE 2 Example 9 73 - 10 10 APO 1 7 TPE 2 Example 10 52 - 30 15 APO 2 3 TPE 1 Example # 11 55 - 15 20 APO 3 10 TPE 1 Example 12 - 58 15 20 APO 1 7 TPE 1 Example # 13 - 63 10 10 APO 2 7 TPE 2 Example # 14 - 73 15 5 APO 3 7 TPE 2

* Glass fiber: CS311 of Kumkang Chemical Co., Ltd.

* APO 1: 7 parts by weight of maleic acid, 3 parts by weight of benzoyl peroxide, 100 parts by weight of polypropylene graft copolymer

* APO 2: 10 parts by weight of maleic acid, 7 parts by weight of benzoyl peroxide, 100 parts by weight of polypropylene graft copolymer

* APO 3: 13 parts by weight of maleic acid, 7 parts by weight of benzoyl peroxide, 100 parts by weight of polypropylene graft copolymer

* TPE 1: graft copolymer of 1 part by weight of maleic anhydride and 100 parts by weight of ethylene octene rubber elastomer

* TPE 2: Graft copolymer of 2 parts by weight of maleic anhydride and 100 parts by weight of ethylene octene rubber elastomer

division Flexural modulus
(Kg / cm ² ) Impact strength
(Kgcm / cm) Shrinkage Deviation
(%) Heat distortion temperature
(℃) Example 1 52,000 8.5 127 230 Example 2 63,000 15 116 232 Example 3 57,000 9 125 235 Example 4 42,500 16 114 210 Example 5 47,000 10 121 190 Example 6 53,000 15.5 126 194 Example 7 44,000 12 119 187 Example # 8 53,000 17 123 182 Example 9 66,000 11 121 205 Example 10 81,000 9 126 240 Example # 11 60,500 15.5 121 236 Example 12 52,000 14 119 190 Example # 13 42,000 16 123 184 Example # 14 58,000 10 127 192

Comparative Example  1 to 14

The polyamide resin composition was prepared in the same manner as in Examples 1 to 14, except that the composition was carried out in the composition shown in Table 3, and each test specimen was manufactured in the same manner to evaluate the physical properties. Is as shown in Table 4 below.

division Nylon 66
(weight%) Nylon 6
(weight%) glass fiber
(weight%) Acid-Modified Polyolefin
(weight%) Thermoplastic Rubber Elastomer
(weight%) Comparative Example 1 48 - 35 10 APO 1 7 TPE 1 Comparative Example 2 75 - 8 10 APO 3 7 TPE 2 Comparative Example 3 70 - 20 3 APO 1 7 TPE 1 Comparative Example 4 - 52 20 23 APO 2 5 TPE 2 Comparative Example 5 - 73 15 10 APO 1 2 TPE 1 Comparative Example 6 - 60 20 8 APO 3 12 TPE 2 Comparative Example 7 - 68 15 10 APO 4 7 TPE 1 Comparative Example 8 - 68 15 10 APO 5 7 TPE 2 Comparative Example 9 68 - 15 10 APO 6 7 TPE 2 Comparative Example 10 68 - 15 10 APO 7 7 TPE 1 Comparative Example 11 - 72 15 8 APO 1 5 TPE 3 Comparative Example 12 - 67 20 8 APO 2 5 TPE 4

* Glass fiber: CS311 of Kumkang Chemical Co., Ltd.

* APO 1: 7 parts by weight of maleic acid, 3 parts by weight of benzoyl peroxide, 100 parts by weight of polypropylene graft copolymer

* APO 2: 10 parts by weight of maleic acid, 7 parts by weight of benzoyl peroxide, 100 parts by weight of polypropylene graft copolymer

* APO 3: 13 parts by weight of maleic acid, 7 parts by weight of benzoyl peroxide, 100 parts by weight of polypropylene graft copolymer

* APO 4: 4 parts by weight of maleic acid, 7 parts by weight of benzoyl peroxide, 100 parts by weight of polypropylene graft copolymer

* APO 5: graft copolymer of maleic acid 18 parts by weight, benzoyl peroxide 7 parts by weight, polypropylene 100 parts by weight

APO 6: 10 parts by weight of maleic acid, 1.5 parts by weight of benzoyl peroxide, 100 parts by weight of polypropylene graft copolymer

APO 7: 10 parts by weight of maleic acid, 10 parts by weight of benzoyl peroxide, 100 parts by weight of polypropylene graft copolymer

* TPE 1: graft copolymer of 1 part by weight of maleic anhydride and 100 parts by weight of ethylene octene rubber elastomer

* TPE 2: Graft copolymer of 2 parts by weight of maleic anhydride and 100 parts by weight of ethylene octene rubber elastomer

* TPE 3: graft copolymer 0.3 parts by weight of maleic anhydride, 100 parts by weight of ethylene octene rubber elastomer

* TPE 4: graft copolymer of 5 parts by weight of maleic anhydride and 100 parts by weight of ethylene octene rubber elastomer

division Flexural modulus
(Kg / cm ² ) Impact strength
(Kgcm / cm) Shrinkage deviation
(%) Heat distortion temperature
(℃) Comparative Example 1 91,000 10 135 250 Comparative Example 2 35,000 7.5 124 173 Comparative Example 3 59,000 11 136 241 Comparative Example 4 46,500 7 133 165 Comparative Example 5 58,000 6.5 126 201 Comparative Example 6 38,000 18 135 171 Comparative Example 7 53,000 10.5 137 178 Comparative Example 8 54,000 7.5 133 173 Comparative Example 9 60,500 7 136 210 Comparative Example 10 57,500 7.5 135 222 Comparative Example 11 53,600 6.5 132 177 Comparative Example 12 61,500 7 123 194

As shown in Tables 1 to 4, in the case of Examples 1 to 14 including polyamide resin, glass fiber, acid-modified polyolefin, and acid-modified rubber elastomer in a specific composition ratio according to the present invention, the degree of graft of each component and Compared to Comparative Examples 1 to 12, the content ratio is out of the range of the present invention, it can be seen that it has excellent properties at the same time in terms of overall physical properties such as flexural modulus, impact strength, shrinkage rate variation, and heat deformation temperature.

As described above, the polyamide resin composition according to the present invention has excellent mechanical strength as it comprises glass fibers, acid-modified polyolefins, and acid-modified rubber elastomers. It can greatly improve the dimensional instability caused by the difference, secure impact resistance, minimize fluid defects, improve the appearance quality of the product, and secure dimensional stability such as warpage and deformation, which is a problem such as shrinkage anisotropy. In particular, in the case of the present invention, as the object of the invention, it is light and inexpensive to manufacture, satisfies rigidity, impact resistance and heat resistance with various physical properties, and there is no warpage or deformation due to problems in forming a product, and also secures a good exterior molded product. At the same time, there is an excellent advantage in that it is used for automobile interior use, for example, a door frame inner cover of an automobile.

Claims (11)

(a) 50 to 80% by weight of a polyamide resin, (b) 10 to 30 weight percent of glass fibers, (c) 5 to 20% by weight of acid-modified polyolefin grafted with 5 to 15 parts by weight of reactive dicarboxylic acid or its anhydride and 2 to 8 parts by weight of organic peroxide, based on 100 parts by weight of polyolefin resin, and (d) 3 to 10% by weight of an acid-modified rubber elastomer in which 0.4 to 3 parts by weight of α, β-unsaturated carboxylic acid is grafted to 100 parts by weight of rubber elastomer, Impact strength of 8 kg · cm / cm or more according to ASTM evaluation method D256, Flexural modulus 40,000 kg / cm ² or more according to ASTM evaluation method D790, Shrinkage rate deviation 130% or less according to the following Formula 1, and Heat distortion temperature over 180 ℃ by ASTM evaluation method D648 Phosphorus polyamide resin composition. [Equation 1]

The method of claim 1, (a) 52 to 77 wt% of a polyamide resin, (b) 12 to 25 weight percent of glass fibers, (c) 7 to 17% by weight of acid-modified polyolefin grafted 5 to 15 parts by weight of reactive dicarboxylic acid or its anhydride and 2 to 8 parts by weight of organic peroxide, based on 100 parts by weight of polyolefin resin, and (d) A polyamide resin composition comprising 4 to 9% by weight of an acid-modified rubber elastomer having 0.4 to 3 parts by weight of α, β-unsaturated carboxylic acid based on 100 parts by weight of the rubber elastomer. The polyamide resin composition of claim 1, wherein the polyamide resin has a relative viscosity of 2.5 to 3.5. The polyamide resin composition according to claim 1, wherein the polyamide resin is nylon 6, nylon 66, or a mixture thereof. The polyamide resin composition according to claim 1, wherein the glass fibers have an average length of 3 to 6 mm and an average diameter of 10 to 13 m. The method of claim 1, The reactive dicarboxylic acid or anhydride thereof may be selected from maleic acid, phthalic acid, itaconic acid, citraconic acid, alkenyl succinic acid, cis-1,2,3,6-tetrahydrophthalic acid, 4-methyl-1,2,3,6 -At least one selected from the group consisting of tetrahydrophthalic acid, and anhydrides thereof, The organic peroxide is benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-di-t-butylperoxide, 1,3-bis (t-butylperoxide) Oxy-isopropyl) benzene, di-t-butylperoxy azelate, 2,5-dimethyl-2, 5-di (t-butylperoxy) hexane, t-butyl cumyl peroxide, t-butylperoxy- 3,5,5-trimethylhexate, p-chlorobenzoylperoxide, t-butyloxybenzoate, methylethylketone peroxide, tris (t-butylperoxy) triazine, t-butylperoxyacetate, and t A polyamide resin composition selected from the group consisting of -butyl peroxy isoprocarbonate. The method of claim 1, wherein the acid-modified rubber elastomer is prepared from at least one unsaturated monomer selected from the group consisting of α-olefins containing ethylene, acrylic acid and its derivatives, aromatic vinyl monomers, vinyl cyanide monomers, and diene monomers. The polyamide resin composition in which the (alpha), (beta)-unsaturated carboxylic acid is grafted to the rubber elastic body used. 8. The method of claim 7, wherein the α, β-unsaturated carboxylic acid is maleic acid, itaconic acid, citraconic acid, acrylic acid, methacrylic acid, allyl succinic acid, 2-dicarboxylic acid, maleic acid, fumaric acid, and anhydrides or derivatives thereof. At least one polyamide resin composition selected from the group consisting of. 8. The polyamide resin composition according to claim 7, wherein the acid-modified rubber elastomer is an ethylene-octene copolymer in which 0.4 to 3 parts by weight of maleic acid is grafted. A polyamide resin molded article comprising the polyamide resin composition according to any one of claims 1 to 9. The molded article of polyamide resin according to claim 10, which is used for an automobile door frame inner cover, an intercooler air duct, a timing belt cover, an engine cover, or a roof rack.