KR100880457B1 - The reinforced polyamide resin composition - Google Patents

Abstract

The present invention relates to a polyamide-reinforced resin composition, and more particularly, comprising a polyamide resin, a glass fiber, an iodine-based heat-resistant agent and a lactone compound, thereby excellent in fluidity of the resin composition, and thus the product produced is light It has good mechanical properties, good overall mechanical properties, especially long-term heat resistance, welding properties and surface properties, and less deformation when molded into a product, so it is more preferable than poly when applied for automobile air intake manifold. It relates to an amide reinforced resin composition.

Polyamide, long term heat resistance, welding characteristic, surface characteristic

Description

The reinforced polyamide resin composition

The present invention relates to a polyamide-reinforced resin composition, and more particularly, comprising a polyamide resin, a glass fiber, an iodine-based heat-resistant agent and a lactone compound, thereby excellent in fluidity of the resin composition, and thus the product produced is light It has good mechanical properties, good overall mechanical properties, especially long-term heat resistance, welding properties and surface properties, and less deformation when molded into a product, so it is more preferable than poly when applied for automobile air intake manifold. It relates to an amide reinforced resin composition.

The automotive industry is a representative industry with high technical demand and rapid technological change. Recently, the automobile industry has actively promoted weight reduction along with alternative energy development. The representative movement of lightweighting is plasticization of automobile materials. Such alternative research has been actively conducted in terms of not only lightweighting but also low manufacturing cost, improved design freedom, and simplified manufacturing process. Therefore, many parts of the engine's peripheral parts have been replaced by plastic products. Recently, research is focused on the development of materials that can maintain the functions of existing products while reducing the weight.

As part of the above-mentioned efforts, among polyamides, especially polyamides have excellent rigidity, toughness, abrasion resistance, chemical resistance, and the like in the automotive industry. In particular, rather than using a polyamide resin alone, inorganic materials such as glass fibers and functional additives are used to satisfy desired functionalities such as high rigidity and heat resistance.

For example, among automotive components, in particular automotive air intake manifolds have been manufactured and applied using metallic materials (particularly aluminum) as their materials, with an emphasis on improving heat resistance and durability. However, when the metal material is used, the durability is excellent, but the manufacturing process is complicated and the product is generally heavy.

In order to improve the above disadvantages, recent automobile air intake manifolds were manufactured by injection molding a composition in which glass fibers surface-treated in polyamide 6 and 66 resin having excellent properties were applied for the purpose of mechanical properties.

The glass fiber-reinforced composition has been applied to a small car mainly made of a small sized product at first, but the related technology has been advanced and divided into a number of pieces using a plurality of molds, and then injection molded and combined by vibrating welding. Complex air intake manifolds can be manufactured, which has been applied to medium and large passenger cars.

When the conventional resin composition is applied to the manufacturing method described above, when the air intake manifold injection molding has a large and complicated structure, the flowability of the resin composition is poor, and the flow of the resin composition is not smooth, and the glass fiber is expressed on the surface of the product, resulting in surface roughness. Will drop. In addition, as the glass fiber is biased in a complicated structure, fine cracking occurs on the surface, thereby deteriorating physical properties, which causes air leakage when used for a long time.

Therefore, in order to replace the plastic material of the air intake manifold with plastic, the mechanical durability, that is, the strength and stiffness, must be improved to a level that satisfies the existing metal materials such as aluminum, as well as vibration welding after injection molding into pieces. It shall have sufficient welding properties as required for bonding. In addition, since it is a material used in the engine system, it should express excellent heat resistance characteristics when used for a long time.

Known techniques for solving the above problems are as follows.

Japanese Patent Laid-Open No. 58-17440 proposes a technique using calcium oxide (CaO) and magnesium oxide (MgO) to improve the surface, and Japanese Patent Laid-Open No. 59-133249 also uses glass fiber to improve fluidity and tensile properties. A plasticizer was added to present a composition with excellent appearance.

U. S. Patent No. 4,613, 647 discloses a technique for introducing aromatic polyamide while reinforcing glass fibers in a polyamide resin to improve heat resistance. U. S. Patent No. 3,843, 591 discloses an interface between an inorganic material and an inorganic material for improving heat resistance and mechanical properties. Coupling agents that enhance adhesion are introduced. In addition, Japanese Patent 1999-315156 proposed a technique for irradiating a cross-linked molded article containing an uncrosslinked amorphous polyamide and a crosslinking agent with a polyamide molded article and a method for producing the same to express excellent heat resistance over a long time. 195291 proposed a technique for enhancing long-term heat resistance using iodine compounds.

European Patent 0,605,005 A2 proposes a technique of applying fluorine-coated white mica to compensate for the disadvantage of introducing too much glass fiber for improving mechanical strength and heat resistance.

As a technique for enhancing vibration welding characteristics, US Pat. No. 4,988,764, Japanese Patent Application Laid-Open No. 60-86162, and Japanese Patent Application Laid-Open No. 60-179455 propose a technique for mixing polyolefin with polyamide. Techniques for using ester group additives of low molecular weight polyethylene glycols have also been presented.

Looking at the prior art as described in detail, there is simply enough technical value for each of the proposed properties reinforcement, most of the composition is composed of properties suitable for injection molded products.

However, there is a deficiency in satisfying the excellent long-term heat resistance, welding characteristics and surface characteristics at the same time.

In other words, when excessive inorganic material is added for excellent mechanical properties, the inorganic material is exposed on the surface of the product, and the quality of the product is degraded. In order to compensate for this, the technology proposed to introduce a coupling agent and fluorine-coated muscovite increases the manufacturing cost during processing. There is a disadvantage.

Addition of plasticizer for excellent surface properties can increase the fluidity to obtain a good-looking injection molding, excellent moldability and impact strength, but decreases rigidity. Polyolefin is applied to enhance welding properties. However, it also leads to degradation of stiffness and long-term heat resistance.

The technique in which aromatic polyamide is introduced while reinforcing polyamide resin with glass fibers in order to express excellent heat resistance properties over a long period of time has a problem in that the surface characteristics of a complicated end product are poor due to poor flow characteristics. Therefore, a method of increasing the molding temperature and the mold temperature or increasing the injection speed at the time of injection molding is used, but this method is not preferable because it not only causes great constraints in processing molding but also lowers productivity.

As described above, the conventionally proposed technique is limited in application because it cannot satisfy both product properties and required performance.

Therefore, the use of a large amount of glass fiber and the application of heat-resistant additives require a technology that can solve the existing problems of surface defects and deterioration of strength and heat resistance characteristics when using conventional techniques for strengthening welding strength. It is true.

Accordingly, the inventors of the present invention have studied to solve the above problems, and as a result, the flowability of the polyamide-reinforced resin composition using glass fibers to give rigidity to the polyamide resin and designed with a new composition containing an iodine compound and a lactone compound It is excellent to be suitable for this injection molding to improve the manufacturing aptitude, thereby satisfying the physical properties of the manufactured product and the performance required in the art to complete the present invention.

Accordingly, the present invention provides a polyamide-reinforced resin composition which improves the fluidity of the composition, which is excellent in processing aptitude of the product, which has excellent mechanical properties such as rigidity, long-term heat resistance and welding characteristics, and at the same time, which exhibits excellent surface properties. The purpose is to provide.

It is also an object of the present invention to provide an improved polyamide reinforced resin composition suitable for automotive parts, in particular for automotive air intake manifold parts.

The present invention features a polyamide-reinforced resin composition comprising 45.0 to 77.98% by weight of polyamide resin, 20.0 to 45.0% by weight of glass fiber, 0.02 to 2.0% by weight of iodine-based heat-resistant agent, and 2.0 to 8.0% by weight of lactone-based compound. .

Hereinafter, the present invention will be described in detail.

The present invention comprises a polyamide resin, a glass fiber, an iodine-based heat-resistant agent and a lactone compound, excellent in the fluidity of the resin composition, the resulting product has a good light weight properties and overall mechanical properties, in particular, long-term The present invention relates to a polyamide-reinforced resin composition which is more preferable when applied to automobile air intake manifolds because of excellent heat resistance, welding characteristics and surface properties, and less deformation during molding into a product.

Hereinafter, each component which comprises the polyamide reinforced resin composition of this invention is demonstrated in detail.

As a 1st component, it is polyamide resin as a base resin which comprises the polyamide reinforced resin composition of this invention.

It is more preferable to use polyamide 6 having the basic structure of the following formula (1) as the polyamide resin, and in particular, the relative viscosity is 2.3 to 3.0 poise (20 ° C., 1 g solution of polyamide 6 resin in 100 ml of 96% sulfuric acid). It is good to use. In this case, when the viscosity of the polyamide resin is less than 2.3, the rigidity and impact resistance may be reduced, and when the viscosity of the polyamide resin is greater than 3.0, surface display of the glass fiber may occur due to poor fluidity.

-(NH- (CH ₂ ) ₅ -CO) _n-

In Formula 1, n is an integer of 200 to 15,000.

The polyamide 6 resin is generally a method of producing polyamide 6, with respect to 100 parts by weight of ε-caprolactam, 7.17 parts by weight of water, 0.004 parts by weight of the bubble inhibitor, and tris- (2.4-dibutylbutylphenyl) -phosphite, which is a heat-resistant agent. 0.09 parts by weight of Iganox B1171 (Irganox B1171, Ciba Specialty Chemicals) which is a mixture of 1: 1 weight of N, N'-hexamethylene bis (3.5-dibutylbutyl-4-hydroxy-hydrocinamide) Into the reaction tube at ℃ ℃ and the pressure up to 15 ㎏ / ㎠ to react for 1 hour and then continue to maintain the pressure for 30 minutes gradually drop the pressure to proceed the reaction for 2 hours at the same pressure as the atmosphere -360 mmHg The reaction was carried out for about 1 hour further under reduced pressure, and the reaction was terminated while adding nitrogen, thereby preparing a desired polyamide 6 resin.

Polyamide 6 obtained by the above-mentioned manufacturing method is more preferably used in the form of a chip (chip) for the final resin composition in accordance with the present invention dried at 85 ℃, 6 hours in a dehumidifying dryer.

As a 2nd component, it is a glass fiber used in order to improve the strength of the polyamide reinforced resin composition of this invention.

It is preferable that the said glass fiber has a fin shape, and is 10-13 micrometers in diameter, and has a length of 3-3.5 mm. The present invention can use a glass fiber called G or K glass, the glass fiber is mainly composed of calcium oxide (CaO), silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), generally calcium oxide This 10-20 weight%, 50-70 weight% of silicon dioxide, and 2-15 weight% of aluminum oxides are contained.

In particular, the surface of the glass fiber is treated with a coupling agent, but the coupling agent is preferably a silane compound having an organic functional group such as a vinyl group, an epoxy group, a mercaptan group or an amine group.

Such glass fiber is used in 20 to 45% by weight of the total composition, when the amount is less than 20% by weight, the rigidity effect is insignificant, when the amount exceeds 45% by weight may cause processing and surface problems have.

By satisfying the above conditions, commercially available CS-311 (Kumgang Chemical Co., Ltd.) may be used.

As a third component, it is an iodine type heat resistant agent which is a component used in the present invention.

Long-term heat resistance is improved by using the iodine-based heat-resistant agent, the iodine-based heat-resistant agent has no effect on the short-term heat resistance represented by the heat deformation temperature when applied to the polyamide resin composition, but the product used at high temperature for a long time This results in stabilization of the heat, which in turn improves the durability of the molded product.

As the iodine-based heat-resistant agent, a cupric iodide (CuI), potassium iodide (KI) or a mixture thereof is used, but it is more preferable to use a mixture rather than a single use. In the case of using a mixture, cuprus iodide and potassium iodide are used in a weight ratio of 1: 1 to 10, wherein the weight ratio is less than 1: 1, that is, if the cuprus iodide content is high, the effect of improving long-term heat resistance is insufficient. In addition, when it exceeds 1:10, the effect of improving the long-term heat resistance is insufficient, which is not preferable.

The iodine-based heat-resistant agent is 0.02 to 2.0% by weight of the total composition, the addition effect is insignificant if the total amount of the iodine-based heat-resistant agent is less than 0.02% by weight, the enhancement of the addition effect is not very large when it exceeds 2.0% by weight. There is a problem that the mechanical properties of the obtained composition are lowered, the surface properties are not good, and the manufacturing cost is increased. Commercially available products such as iodine-based heat-resisting agents may be used, such as couprus iodide (produced by NOAHTECH) and potassium iodide (produced by NOAHTECH).

As a fourth component, a component which improves the fusion characteristics is a lactone compound.

The lactone compound is a component that provides excellent vibration welding properties and surface properties, and when used as a component of the resin composition, slows down the crystallization rate of the polyamide resin, thereby acting as a flow improving agent. Excellent moldability and surface properties make product design more free. In addition, there is an adhesive property when heat is applied, thereby making the end product excellent by welding properties between the parts molded by the kinetic energy of the molecules due to the vibration during welding.

Among these lactone compounds, polycaprolactone is more preferable. The polycaprolactone is a compound prepared by polymerizing caprolactone having excellent reactivity, flexibility, and solubility characteristics produced by the reaction of cyclohexanone and peracetic acid. It is characterized by qualitative, low melting point and flexibility.

The amount of the lactone compound used is 2.0 to 8.0% by weight in the total composition, and when the amount is less than 2.0% by weight, the effect of improving the surface and enhancing the welding property by the improvement of fluidity is insignificant, and the viscosity is greater than 8.0% by weight. It is not preferable because there is a disadvantage in that the mechanical strength and long-term heat resistance properties are lowered by causing a decrease. As a commercially available product, Placcel H7 (product of DAICEL CHEMICAL) can be used.

On the other hand, tris- (2,4-dibutylbutylphenyl) -phosphate and N, N'-hexamethylene bis (3,5-diethyl-4-) having an amide group within a range not impairing the object of the present invention. It is also possible to add Iganox B1171 (trade name, manufacturer: Ciba Specialty Chemicals), which is a 1: 1 mixture of hydroxy-hydrocinamide, and select a releasing agent or a coloring agent according to the purpose and purpose of the final product. Can be added.

The polyamide resin composition of the present invention may be prepared by extruding the above-mentioned composition components using an extruder, and may be prepared by kneading at 255 to 265 ° C. using a twin screw extruder as the mixer. In order to maximize the kneading of the resin composition, it is preferable to inject the glass fiber into the secondary inlet of the polyamide resin and the heat-resistant agent in the primary inlet by using an extruder having two inlets. In addition, it is preferable to minimize the residence time in order to prevent thermal decomposition of the composition during melt kneading, and in the present composition, it is necessary to adjust the optimum screw rotation speed in consideration of dispersibility, and the rotation speed of about 200 to 300 rpm is appropriate.

The polyamide-reinforced resin composition of the present invention as described above is excellent in fluidity and good molding suitability of the product, has excellent long-term heat resistance, welding properties and surface properties can be applied to various industrial fields, in particular automotive air intake manifold More effective when applied to fold components.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the following Examples.

Examples 1-18 and Comparative Examples 1-8

Next melted and kneaded in a twin screw extruder heated to 265 ℃ according to the composition of Table 1 and made into a chip (Chip) state by using a screw-type injection machine heated by drying using a dehumidifying dryer at 85 ℃, 6 hours, and when Each specimen was prepared at the same temperature, and the physical properties were evaluated by the method shown in the following experimental example, and the results are shown in Table 2 below.

division Polyamide 6 (% by weight) Fiberglass ¹⁾ (wt%) Heat Resistant (wt%) Polycaprolactone ⁴⁾ (% by weight) CuI ²⁾ KI ³⁾ Example One 77.98 20.0 0.01 0.01 2.0 2 77.98 20.0 0.002 0.018 2.0 3 76.0 20.0 1.0 1.0 2.0 4 76.0 20.0 0.19 1.81 2.0 5 71.98 20.0 0.01 0.01 8.0 6 71.98 20.0 0.002 0.018 8.0 7 70.0 20.0 1.0 1.0 8.0 8 70.0 20.0 0.19 1.81 8.0 9 52.98 45.0 0.01 0.01 2.0 10 52.98 45.0 0.002 0.018 2.0 11 51.0 45.0 1.0 1.0 2.0 12 51.0 45.0 0.19 1.81 2.0 13 46.98 45.0 0.01 0.01 8.0 14 46.98 45.0 0.002 0.018 8.0 15 45.0 45.0 1.0 1.0 8.0 16 45.0 45.0 0.19 1.81 8.0 17 76.0 20.0 - 2.0 2.0 18 76.0 20.0 2.0 - 2.0 Comparative example One 76.0 18.0 0.2 0.8 5.0 2 47.0 47.0 0.2 0.8 5.0 3 61.982 33.0 0.004 0.014 5.0 4 59.8 33.0 0.5 1.7 5.0 5 61.0 33.0 0.6 0.4 5.0 6 61.0 33.0 0.08 0.92 5.0 7 65.0 33.0 0.2 0.8 1.0 8 57.0 33.0 0.2 0.8 9.0 1) CS-311 (Silane Coupling Agent), Kumkang Chemicals 2) Cuprus Iodide, NOAHTECH Co. 3) Potassium Iodide, NOAHTECH Co. 4) Placcel H7, DAICEL CHEMICAL Co.

Experimental Example: Measurement of Physical Properties

Physical properties of the specimens prepared according to Examples 1 to 18 and Comparative Examples 1 to 8 were measured by the following methods.

1) Tensile strength: measured according to ASTM D638 after making a 1/8 inch specimen.

2) Long-term heat resistance: According to ASTM D638, 1/8 inch specimens were prepared, and the tensile strength retention was measured after standing at 135 ° C. for 3,000 hours.

3) Surface characteristics: After drying the resin composition of the present invention made after melt kneading in a chip state using a dehumidifying dryer for 6 hours at 85 ° C., a 150-ton injection molding machine is 350 mm wide, 100 mm long and 2.8 thick. Using a square mold of direct gate type with a diameter of 7 mm and a length of 80 mm in a cavity of mm, the injection temperature is fixed at 270 ° C and the mold temperature at 20 ° C. Among the molded products released under the conditions of kg / cm 2 and injection time 4 seconds and cooling time 18 seconds, glass fiber expression and flow marks in the gate area were visually observed.

4) Welding Strength: According to ASTM D638, make 1/8 inch specimen and cut the middle of the specimen. Vibration Welding Machine of BRANSON's VW2800J-UC (Maximum Welding Area: 105 ㎡) After the vibration welding by using a stand for 3,000 hours at 135 ℃ tensile strength retention was measured.

As described above, according to the present invention, it is possible to produce a polyamide-reinforced resin composition having excellent fluidity, improving the manufacturability of the product, and having excellent long-term heat resistance, welding properties and surface properties.

That is, the mechanical strength was secured by reinforcing the glass fiber based on the toughness and additive effect of the polyamide resin, and the long-term heat resistance using iodine-based heat-resistant agent and the lactone-based compound were applied for excellent surface and welding. It is possible to obtain excellent polyamide-reinforced resin compositions for products that require complex properties but require excellent mechanical properties and formability, which can be applied to various industrial fields requiring long-term heat resistance and durability and formability. More effective when applied to automotive air intake manifolds.

Claims (8)

45.0 to 77.98% by weight of polyamide resin, 20.0 to 45.0% by weight of glass fiber coated with silane coupling agent, 0.02 to 2.0% by weight of iodine-based heat resistant agent, and 2.0 to 8.0% by weight of lactone compound Amide reinforced resin composition. The polyamide reinforced resin composition according to claim 1, wherein the glass fiber has a diameter of 10 to 13 µm and a length of 3 to 3.5 mm. delete The polyamide reinforced resin composition according to claim 1, wherein the silane coupling agent is a silane compound having an organic functional group selected from a vinyl group, an epoxy group, a mercaptan group and an amine group. The polyamide-reinforced resin composition of claim 1, wherein the iodine-based heat-resistant agent is cupric iodide (CuI), potassium iodide (KI) or a mixture thereof. The polyamide-reinforced resin composition according to claim 5, wherein the mixture of cupric iodide (CuI) and potassium iodide (KI) is in a weight ratio of 1: 1 to 10. The polyamide reinforced resin composition according to claim 1, wherein the lactone compound is polycaprolactone. Claims 1, 2 and 4 to 7 consisting of the composition defined in any one of the claims, according to ASTM D638 long-term heat resistance characteristics that maintain the tensile strength retention of 85% or more after standing at 135 ℃ for 3,000 hours Air intake manifold for automobiles, characterized by having.