KR100591449B1 - Polyamide / Polyethylene Compound Blend Resin Compositions - Google Patents

Abstract

The present invention relates to a polyamide / polyethylene compound blend resin composition,

A polyamide / polyethylene compound blend resin composition comprising: 25 to 95 weight percent of a polyamide resin; 3 to 73 wt% polyethylene compound resin; 1 to 30% by weight of the modified polyethylene compound resin; And 0.1 to 3% by weight of styrene-maleic anhydride copolymer, which has excellent impact resistance by the polyamide / polyethylene compound blend resin composition according to the present invention, and also has barrier properties to solutions and gases. ) Has an excellent effect.

Polyamide Resin, Polyethylene Compound Resin, Modified Polyethylene Compound Resin, Styrene-maleic Anhydride Copolymer

Description

Polyamide / Polyethylene compound blend resin composition {RESIN COMPOSITION BLENDED POLYAMIDE WITH POLYETHYLENE COMPOUND}

Figure 1a is a schematic diagram showing a mechanism that the polyethylene compound resin exhibits barrier properties to solvents or gases.

FIG. 1B is a schematic diagram showing a mechanism in which a resin having barrier properties shows a barrier property to a solvent or a gas by forming a multilayer structure.

FIG. 1C is a schematic diagram showing a mechanism in which a resin having a barrier property forms a plate-like structure and shows barrier property to a solvent or a gas.

FIG. 1D is a schematic diagram showing a mechanism in which a resin having barrier properties forms a continuous phase and shows barrier properties to a solvent or a gas.

2 is a cross-sectional view of a polyamide / polyethylene compound blend resin in which the polyamide resin content is 35% by weight and the polyethylene compound resin is in a continuous phase.

3 is a cross-sectional view of a polyamide / polyethylene compound blend resin in which the polyamide resin content is 35% by weight and the polyamide resin is in a continuous phase.

4 is a cross-sectional view of a polyamide / polyethylene compound blend resin without compatibilizers.

5 is a cross-sectional view of a polyamide / polyethylene compound blend resin to which 1 wt% of styrene-maleic anhydride copolymer is added.

* Brief description of the main symbols in the drawings *

1: polyethylene compound resin

2: polyamide resin

The present invention relates to a polyamide / polyethylene compound blend resin composition. More specifically, the present invention relates to a polyamide / polyethylene compound blend resin composition having excellent impact resistance and moldability and excellent barrier properties to solutions and gases.

Polyethylene compound resin, which is one of polyolefin resins, is the most common plastic, and is widely used in daily necessities, toys, mechanical parts, electrical / electronic parts, and automobile parts due to its excellent moldability, impact resistance, ease of handling, and low price. .

However, in order to secure safety, preservation, and environmental pollution prevention, a material capable of preventing leakage of the contents and blocking the incorporation of external air, that is, a material having a blocking property against a solution and a gas, is required. Compound resins have a low barrier to hydrophobic solutions such as gasoline and toluene, which limits their range of use and requires improvement.

Polyamide resins are excellent in rigidity, toughness, chemical resistance, abrasion resistance, solution and gas barrier properties, and are widely used in automotive, electrical, electronic, and various industrial fields. However, there is a problem that the dimensional stability is poor due to the water hygroscopicity due to the amide bond, and the impact strength is very low.

Various studies have been conducted to overcome the above problems, that is, to prepare blend resins having excellent barrier properties to solutions and gases and excellent moldability and impact resistance.

Conventionally, the representative method for improving the impact resistance of a polyamide resin has been the method of mixing an impact reinforcing material with a polyamide resin.

US Patent No. 4,803,247 discloses a method of mixing nitrile rubber as an impact reinforcing material, and US Patent Registration No. 5,919,865 discloses a method of mixing SBS rubber grafted with maleic anhydride as an impact reinforcing material. have.

However, the most representative impact modifiers are polyolefin resins such as ethylene-propylene rubber (EPR) or ethylene-propylene-diene monomer rubber (EPDM).

US Patent No. 4,174,358 discloses a method for mixing 1 to 40% by weight of a polyolefin-based impact modifier grafted with maleic anhydride to 60 to 99% by weight of a polyamide resin.

Since the polyolefin and the polyamide resin have very low compatibility, in order to prepare a blend resin having excellent impact resistance by mixing the two resins, a modified polyol refin grafted with a reactor capable of reacting with a polyamide resin such as maleic anhydride Resins or mixtures of polyolefin resins and modified polyolefin resins should be used. When the polyolefin resin and the modified polyolefin resin are mixed and used, the modified polyolefin resin serves as a compatibilizer between the polyamide resin and the polyolefin resin.

In addition, as a research focused on the development of a material having excellent solution and gas barrier properties and excellent formability,

U.S. Patent No. 4,814,379 discloses materials that can be applied to automotive fuel injectors using 45 to 55 weight percent polyamide resins and 55 to 45 weight percent modified polyolefin resins.

In addition, Japanese Patent Laid-Open No. 2002-275313 discloses that when a polyolefin resin and a polyamide resin having a specific viscosity behavior are mixed, a portion where the polyolefin resin forms a continuous phase and a portion where the polyamide resin forms a continuous phase coexist. The method for producing a resin molded article having excellent barrier properties is disclosed.

In preparing such polyamide / polyolefin blend resins, the use of a compatibilizer is essential to derive sufficient compatibility between the two resins to achieve the desired impact resistance and barrier properties. However, currently known compatibilizers are mostly modified polyolefin resins prepared by modifying them to include a reactor capable of reacting with a polyamide resin, and in order to obtain sufficient compatibility in producing polyamide / polyolefin blend resin commercial products, There was a problem that a positive modified polyolefin resin should be added.

In addition, in many cases, the whole impact reinforcing material is used only as a modified polyolefin resin, and there is a problem of increasing the production cost.

In order to solve the above problems, the present invention, in the preparation of the polyamide / polyethylene compound blend resin composition, through the introduction of a new compatibilizer called styrene-maleic anhydride copolymer in addition to the modified polyethylene compound resin, It is an object to provide a polyamide / polyethylene compound blend resin composition which is excellent in impact resistance and toughness and excellent in barrier property against solvents and gases while reducing the amount.

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 provides a polyamide / polyethylene compound blend resin composition comprising: a) 25 to 95 wt% of a polyamide resin; b) 3 to 73 wt% of a polyethylene compound resin; c) 1 to 30% by weight of the modified polyethylene compound resin; And d) 0.1 to 3% by weight of a styrene-maleic anhydride copolymer to provide a polyamide / polyethylene compound blend resin composition.

The polyamide resin may be selected from the group consisting of nylon 6, nylon 66, nylon 6/66 and a resin containing an amide group in a molecular structure in the polyamide / polyethylene compound blend resin composition manufacturing process.

The polyethylene compound resin may be at least one selected from the group consisting of polyethylene, ethylene-propylene rubber, ethylene-octene rubber, and ethylene-propylene-diene monomer rubber.

The modified polyethylene compound resin may be selected from the group consisting of polyethylene, ethylene-propylene rubber, ethylene-octene rubber, or a resin in which maleic anhydride is grafted to a polyethylene compound resin of ethylene-propylene-diene monomer rubber.

The styrene-maleic anhydride copolymer is a resin in which 0.5 to 30% by weight of maleic anhydride is copolymerized with styrene.

Hereinafter, the present invention will be described in detail.

The present invention comprises a) 25 to 95% by weight of a polyamide resin; b) 3 to 73 wt% of a polyethylene compound resin; c) 1 to 30% by weight of the modified polyethylene compound resin; And d) 0.1 to 3% by weight of a styrene-maleic anhydride copolymer, to provide a polyamide / polyethylene compound blend resin composition.

The polyamide resin may be a single or two or more polycondensation of a ring structure lactam or ω-amino acid having a three-membered ring or more as a monomer, diacids and diamine may be used. In addition, homopolyamides, copolyamides, and mixtures thereof may be used, and such polyamide resins may be semi-crystalline and / or amorphous.

Specifically, for example, a monomer which can be polymerized alone, or selected solely from ε-caprolactam, aminocaproic acid, enanthlactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid, α-piperidone, or the like. There are two or more polymers, and in the case of polycondensation of diacid and diamine, tetramethylenediamine, hexamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, paraaminoaniline, and methaxylenediamine, etc. Polyamide obtained through the polycondensation reaction of diamine, dipic acid, sebacic acid, dodecanediic acid, glutaric acid, terephthalic acid, 2-methyl terephthalic acid, isophthalic acid and naphthaledicarboxylic acid Polymers or copolymers can be used.

Moreover, 0.1-5 mol% can also be used for polyfunctional compounds, such as tremetic acid containing 3 or more functional groups other than the said diacid or diamine.

In addition, polyamide resins which partially retain the monomers of the aforementioned nylons can also be used to increase the flexibility and viscosity in the polymerization process.

More specifically, such polyamide resins include nylon 6, 7, 8, 10, 12, 66, 69, 610, 611, 612, 6T, 6/66, 6/12 and 6 / 6T, and the like. Among them, nylon 6, nylon 66, nylon 6/66 and the like are preferred. In addition, the polyamide resin is a resin containing an amide group in the molecular structure. In addition, the polyamide resins may be selected one or more. That is, it can be used as a mixture of any combination and content ratio of the above polyamide resins.

Even in the polymerization method, any one of the polymerization methods, such as anionic polymerization, bulk melt polymerization, solution polymerization, melt polymerization through salt, interfacial polymerization and reaction extrusion, is not limited to use. Polyamide copolymers polycondensed using monomers of the phase can be used regardless of the content ratio of the components.

The polyamide resin obtained as described above can be used in 25 to 95% by weight of the total polyamide / polyethylene compound blend resin composition.

The polyethylene compound resin is a thermoplastic resin obtained by polymerizing or copolymerizing ethylene. As a specific example, 1 or more types can be selected from the group which consists of polyethylene, an ethylene propylene rubber (EPR), an ethylene octene rubber (EOR), an ethylene propylene-diene monomer (EPDM) rubber, etc.

The polyethylene compound resin obtained as described above may be used in an amount of 3 to 73% by weight in the total polyamide / polyethylene compound blend resin composition.

The modified polyethylene compound resin is a resin in which the maleic anhydride having excellent reactivity with the amide functional group of the polyamide resin is grafted to the polyethylene compound resin. Specific examples include polyethylene graft maleic anhydride (PE-g-MA), ethylene-propylene rubber graft maleic anhydride (EPR-g-MA), ethylene-octene rubber graft maleic anhydride (EO-g-MA) and ethylene-propylene The diene monomer rubber graft maleic anhydride (EPDM-g-MA) or the like can be selected from one or more.

The modified polyethylene compound resin obtained as described above may be used in an amount of 1 to 30% by weight in the total polyamide / polyethylene compound blend resin composition.

The styrene-maleic anhydride copolymer is a resin in which 0.5 to 30% by weight of maleic anhydride is copolymerized with styrene, and has excellent reactivity with the amide functional group of the polyamide resin, and the polyamide resin, polyethylene compound resin, and modified polyethylene compound. When added to the resin mixture 0.1 to 5% by weight can reduce the interfacial tension between the polyamide resin and the polyethylene compound resin, and consequently serves to increase the impact resistance of the polyamide / polyethylene compound blend resin. In addition, polyamide resins in polyamide / polyethylene compound blend resins facilitate the formation of a continuous phase, allowing the polyamide resin to maintain a continuous phase even in low polyamide / polyethylene compound blends. Therefore, the present invention is excellent in blocking properties for solutions and gases.

In preparing the polyamide / polyethylene compound blend resin, by selecting a polyamide resin, a polyethylene compound resin and a modified polyethylene compound resin having a suitable viscosity and adding a styrene-maleic anhydride copolymer to the moldability, impact resistance, Blend resins having excellent barrier properties to solutions and gases can be prepared.

The styrene-maleic anhydride copolymer is preferably used in the polyamide / polyethylene compound blend resin composition of the present invention in an amount of 0.1 to 5 wt%, more preferably in an amount of 0.1 to 3 wt%.

However, when the styrene-maleic anhydride copolymer is added in an amount of 0.1 wt% or less, the addition effect is insignificant, and when it is added in an amount of 5 wt% or more, the impact resistance and the barrier property to solution and gas are reduced. As it occurs, it is necessary to add an appropriate amount of styrene-maleic anhydride copolymer, and in addition, when used properly mixed with a modified polyethylene compound resin, which is an existing compatibilizer, optimum physical properties can be obtained.

The content of the process according to the present invention will be described below with reference to the drawings.

The principle of the present invention having barrier properties for solution and gas will be described with reference to FIGS. 1A to 1D and Table 1 from the conventional resins.

Figure 1a is a polyethylene compound resin, as shown in Table 1 is very excellent in terms of moldability, equipment investment cost and recyclability, but the barrier properties for hydrophobic solutions such as gasoline, toluene, etc. is very limited, its use is limited.

Therefore, there are kinds of materials such as resins having barrier properties, such as resins having a multilayer structure and a plate structure.

1B is a multilayer structure material in which a resin having high barrier properties is bonded to a resin having good moldability. As shown in Table 1, the barrier property is very excellent, but an expensive processing device capable of molding a product having a multilayer structure is required. In addition, there is a processing problem that the blocking characteristic material should not be broken in the molding process.

In addition, FIG. 1C is a material in which a material having excellent blocking characteristics is dispersed in a plate shape, and a commercial product such as selar is manufactured using this technology. As shown in Table 1, these materials have the advantage of being able to obtain the barrier properties while using a small amount of barrier properties, but special processing conditions must be applied to make the plate with excellent barrier properties. There was a problem that the barrier properties tend to fall off when the plate or tube form is complicated.

Therefore, Figure 1d is made to achieve a continuous phase of the material having excellent blocking properties to solve the above problems, when making such a material, as shown in Table 1, the molding difficulties, increase in raw material costs, impact resistance It effectively solves the degradation problem, and has the effect of excellent recyclability, barrier properties for solutions and gases.

TABLE 1

Polyethylene compound Multilayer structure Plate structure The present invention  Blocking characteristics × ○ △ ○  Formability ○ × △ ○  Equipment investment cost ○ × ○ ○  Recyclability ○ × △ ○

Note) ○: Excellent, △: Normal, ×: Poor

In general, the polyamide resin content must be high in order for the polyamide resin to form a continuous phase. However, the polyamide resin has a low viscosity, making it very difficult to manufacture a product by a molding method such as blow molding, and thus, the higher the content of the polyamide resin in the polyamide / polyethylene compound blend resin, the lower the moldability. However, in the present invention, a low viscosity polyamide resin, a high viscosity polyethylene compound resin and a modified polyethylene compound resin are used, and a styrene-maleic anhydride copolymer is added to form a continuous phase even with a low content of polyamide resin. Made to help minimize this formability degradation. The use of styrene-maleic anhydride copolymer in the polyamide / polyethylene compound blend resin confirmed that the polyamide resin can lower the content capable of forming a continuous phase through structural observation using an electron microscope.

2 and 3 are polyamide / polyethylene compound blend resins having the same content of polyamide resin. However, in the case of FIG. 2, while the polyethylene compound resin (1) forms a continuous phase, the polyamide resin (2) forms a continuous phase in the blend resin of FIG. 3 to which 1% of styrene-maleic anhydride copolymer is added. can confirm.

In addition, in general, when the polyamide resin forms a continuous phase, impact resistance is lowered. To solve this problem, a large amount of compatibilizer must be used. However, in the present invention, the impact resistance can be greatly improved by adding a styrene-maleic anhydride copolymer in addition to the modified polyethylene compound resin that is conventionally used as a compatibilizer. Brief description of the styrene-maleic anhydride copolymer can be used as a compatibilizer in the polyamide / polyethylene compound blend resin is as follows.

In general, when preparing a ternary polymer blend resin, one component may form a continuous phase, and the other two components may each independently form a dispersed phase, or one component may have a structure such as surrounding another component. The structure is determined by the interfacial tension between the components, the structure is formed in a direction to minimize the interfacial tension of the entire system. In the polyamide / polystyrene / polyethylene compound ternary blend resin, when the polyamide resin forms a continuous phase, the polystyrene resin surrounds the polyethylene compound resin, that is, the structure in which the polystyrene resin is located between the polyamide resin and the polyethylene compound resin Will have Therefore, when the styrene derivative styrene-maleic anhydride copolymer is added to the polyamide / polyethylene compound blend resin, it is located at the interface of the two resins and serves to reduce the interfacial tension between the two resins.

The fact is that when the styrene-maleic anhydride copolymer of FIG. 5 is added in an amount of 1% by weight compared to the simple polyamide / polyethylene compound blend resin of FIG. You can check it.

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

Preparation Step 1: Preparation of Raw Materials Used in Examples 1 and 2 and Comparative Examples 1 and 2

Polyamide resin is Honeywell's nylon 6, polyethylene compound resin is Daelim's high density polyethylene (HDPE), Kumho's ethylene-propylene rubber (EPR) and modified polyethylene compound resin is Crompton's polyethylene graft maleic anhydride ( PE-MA) and ethylene-propylene rubber graft maleic anhydride (EPR-MA) from Exxonmobil, and the styrene-maleic anhydride copolymer (SMA) is a copolymer of about 8% maleic anhydride from Nova chemicals. Was used.

Example 1

35 wt% nylon 6, 58 wt% high density polyethylene (HDPE), 2 wt% ethylene-propylene rubber graft maleic anhydride (EPR-MA), 4 wt% polyethylene graft maleic anhydride (PE-MA) and styrene-maleic anhydride 1% by weight of Ixane copolymer (SMA) was dry blended and melt mixed at 240 ° C. using a twin screw extruder to obtain pellets using a pelletizer, and then dried at 90 ° C. in a dehumidifying dryer and then molded in an injection molding machine.

Example 2

Using a twin screw extruder by dry blending in the same manner as in Example 1 except that 50% by weight of HDPE and 8% by weight of ethylene-propylene rubber (EPR) were applied instead of 58% by weight of HDPE. After melt mixing at ℃, the pellets were obtained by a pelletizer, and then dried in a dehumidifying dryer at 90 ℃ and molded in an injection molding machine.

Comparative Example 1

Example except that 4% by weight of polyethylene graft maleic anhydride (PE-MA) and 5% by weight of polyethylene graft maleic anhydride (PE-MA) were applied instead of 1% by weight of styrene-maleic anhydride copolymer (SMA). Dry blending in the same manner as in 1 and melt-mixed at 240 ℃ using a twin screw extruder to obtain a pellet with a pelletizer, then dried at 90 ℃ dehumidifying dryer and molded in an injection molding machine.

Comparative Example 2

100% by weight of high density polyethylene (HDPE) was dry blended and melt mixed at 240 ° C. using a twin screw extruder to obtain pellets using a pelletizer, and then dried at 90 ° C. in a dehumidifying dryer and then molded in an injection machine.

In addition, the said blocking characteristic was tested by the following method.

Using a blow molding machine to prepare a container with the resins of Examples 1 and 2 and Comparative Examples 1 and 2, a predetermined amount of Fuel C (mixture of 80% by volume of toluene and 20% by volume of iso-octane) was prepared in the prepared container. After filling and sealing, it was placed in a 40 ° C. dryer and the change in mass with time was measured. Table 2 below shows the measurement results and blocking characteristics of the injected specimen.

TABLE 2

Classification (wt%) Tensile Strength (㎏ / ㎠) Elongation (%) Flexural Strength (㎏ / ㎠) Flexural modulus (㎏ / ㎠) Impact Strength (㎏ · cm / ㎝) Breaking characteristic (g / day) Continuous phase Example One 358 > 200 367 8,700 39 7.4E-5 Polyamide 2 325 > 200 327 7,200 65 1.2E-4 Polyamide Comparative example One 346 120 345 8,000 11 1.4E-2 Polyethylene 2 269 > 200 232 5,800 24 1.2E-1 Polyethylene

Note: Tensile strength and elongation: ASTM D638, 50mm / min

     Flexural Strength and Flexural Modulus: ASTM D790, 1.3mm / min

     Izod impact strength (at room temperature): ASTM D256, 1/4 inch thick specimen, Izod notched

As can be seen in Table 2 above, the styrene-maleic anhydride copolymer is added as a compatibilizer for the polyamide / polyethylene compound blend resin, so that the impact strength of the modified polyethylene compound resin is increased. Could improve. In addition, it can be seen that by helping the polyamide resin to form a continuous phase, the barrier properties for solution and gas can be increased by more than 1000 times compared to the polyethylene compound resin.

As described above, the polyamide / polyethylene compound blend resin composition according to the present invention can improve impact resistance and moldability by adding a styrene-maleic anhydride copolymer as a compatibilizer in addition to the modified polyethylene compound resin used in the prior art. In addition, it is a useful invention that has the effect of greatly increasing the barrier properties for solutions and gases.

While the invention has been described in detail above with reference to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope and spirit of the invention, and such modifications and variations fall within the scope of the appended claims. It is also natural.

Claims (5)

a) 25 to 95% by weight of a polyamide resin selected from the group consisting of nylon 6, nylon 66, nylon 6/66 and a resin containing an amide group in the molecular structure; b) 3 to 73% by weight of a polyethylene compound resin selected from the group consisting of polyethylene, ethylene-propylene rubber, ethylene-octene rubber, and ethylene-propylene-diene monomer rubber; c) 1 to 30% by weight of a modified polyethylene compound resin grafted with an amide function of a polyamide resin and maleic anhydride to a polyethylene compound resin of polyethylene, ethylene-propylene rubber, ethylene-octene rubber, or ethylene-propylene-diene monomer rubber ; And d) 0.1 to 3% by weight of styrene-maleic anhydride copolymer in which 0.5 to 30% by weight of maleic anhydride is copolymerized with styrene Polyamide / polyethylene compound blend resin composition comprising a. delete delete The method of claim 1, The modified polyethylene compound resin is polyethylene graft maleic anhydride (PE-g-MA), ethylene-propylene rubber graft maleic anhydride (EPR-g-MA), ethylene-octene rubber graft maleic anhydride (EO-g-MA) And ethylene-propylene-diene monomer rubber graft maleic anhydride (EPDN-g-MA). The polyamide / polyethylene compound blend resin composition characterized by the above-mentioned. delete

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