KR101164145B1 - Polycarbonate resin composition with superior scratch resistance - Google Patents

Abstract

The present invention relates to a high scratch resistance polycarbonate resin composition. High scratch resistance polycarbonate resin composition of the present invention is 60 to 90% by weight of polycarbonate; 10 to 40 weight percent polyarylate; And 0.1 to 2% by weight of an epoxy functional chain extender, wherein a shear stress of 100 to 200 kgf / cm 2 is applied during mixing of the components and discharging of the composition for producing a molded article. The high scratch resistance polycarbonate resin composition according to the present invention can be easily used for injection molding or extrusion molding with relatively short process time by improving scratch resistance without degrading the excellent mechanical and appearance properties of the polycarbonate. .

Polycarbonate, scratch resistant

Description

Polycarbonate resin composition with superior scratch resistance

The present invention relates to a high scratch resistance polycarbonate resin composition and a molded article produced using the same. More specifically, the present invention relates to a high scratch resistant polycarbonate resin composition and a molded article manufactured using the same, which can be suitably used for injection molding or extrusion molding while maintaining excellent scratch resistance while maintaining excellent properties of the polycarbonate.

Polycarbonate, which is generally classified as an engineering plastic, is transparent because it is amorphous as a thermoplastic resin prepared by reacting bisphenol A with phosgene. In addition, it is known to have high mechanical strength, excellent heat resistance and electrical insulation, and the highest impact strength among thermoplastic resins. In addition, it is a plastic that is resistant to environmental changes because it has very few dimensional changes due to moisture absorption and stable physical properties according to temperature changes. Due to such excellent mechanical properties and transparency, it is widely used in electrical and electronic materials, housings of home appliances, automobile materials, and various colors can be expressed in addition to the transparency of the polycarbonate resin composition itself.

However, the polycarbonate resin composition, as mentioned above, has suitable characteristics for use in the appearance of the product, but the surface damage easily occurs during the injection process due to the weak scratch resistance, which greatly reduces the value of the product. Thrown away. In addition, there is a problem that product damage easily occurs even while the actual user purchases and uses the product. Therefore, while maintaining the advantages of the existing polycarbonate resin, there is a continuous demand for improvement of the weak scratch resistance.

Accordingly, the problem to be solved by the present invention is to provide a polycarbonate resin composition which is improved in scratch resistance and capable of injection molding or extrusion molding while maintaining the excellent mechanical properties of the conventional polycarbonate resin. In addition, by using the above polycarbonate resin composition, it is to provide a molded article that is long in value preservation and easy to handle compared to a molded article produced by a conventional polycarbonate resin composition.

In order to solve the above problems, the high scratch resistance polycarbonate resin composition of the present invention is 60 to 90% by weight of polycarbonate; 10 to 40 weight percent polyarylate; And 0.1 to 2% by weight of an epoxy functional chain extender, wherein a shear stress of 100 to 200 kgf / cm 2 is applied upon mixing the components and discharging the composition to prepare a molded article.

The highly scratch resistant polycarbonate resin composition of the present invention can secure high compatibility between the polycarbonate resin and the arylate resin through an epoxy functional chain extender, and can exhibit improved scratch resistance due to the arylate resin. . In addition, the introduction of epoxy functional chain extender can lead to a sufficient reaction for improving the physical properties in the process having a short time, such as injection or extrusion process, can be applied to the injection or extrusion process, short production time and continuous Production is possible, the degree of reaction can be controlled by controlling the process conditions, thereby controlling the surface hardness.

The high scratch resistance polycarbonate resin composition of the present invention may further comprise 0.1 to 0.3% by weight of a phenolic antioxidant, and the above-described polycarbonate resin composition of the present invention may be prepared in various molded articles.

The high scratch resistance polycarbonate resin composition according to the present invention has a scratch resistance in a polycarbonate material having a high specific gravity widely used in the appearance of battery electronic products and automobile materials by introducing a polyarylate and an epoxy functional chain extender into the polycarbonate. It can increase the productivity by reducing the defect rate caused by the scratch between the product injection process and can facilitate the handling of the product.

In addition, since the transparency is maintained, it can be used for both transparent and opaque products, so the range of application is wide. In addition, it is easy to use the molded product because there is no drop in the overall mechanical properties. In addition, the product can be easily produced through a reaction extrusion process or an injection process rather than a synthesis method.

Hereinafter, the present invention will be described in detail. The terms or words used in this specification and claims are not to be construed as limiting in their usual or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best explain their invention in the best way possible. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

The polycarbonate used in the high scratch resistance polycarbonate resin composition of the present invention preferably has a weight average molecular weight of 17,000 to 30,000. Polycarbonates in the above molecular weight range have the advantage of being suitable for extrusion or injection processes. If the molecular weight is less than 17,000, since the sufficient amount of polymerization was not reached, the physical properties of the final product are inferior, and the effect of mixing is reduced due to the collapse of the viscosity ratio during melt mixing with polyarylate. In addition, when the molecular weight is more than 30,000, the production of the injection molding becomes difficult due to too high viscosity and the productivity may be sharply lowered. As the polycarbonate usable in the present invention, polycarbonates prepared by various polymerization methods may be used. Preferably, polycarbonates polymerized by interfacial polymerization or melt polymerization may be used, and more preferably, polycarbonates polymerized by melt polymerization. Use is advantageous in terms of reactivity.

Polycarbonate according to the invention is characterized in that it comprises 60 to 90% by weight relative to the total weight of the composition. If the content is less than 60% by weight, as the amount of the arylate resin increases, a sharp increase in viscosity occurs in the mixing process, resulting in a decrease in productivity. If the content is more than 90% by weight, sufficient scratch resistance cannot be exhibited.

In addition, the high scratch resistance polycarbonate resin composition of the present invention contains a polyarylate.

The arylate resin according to the present invention preferably uses a resin having a higher elasticity than the polycarbonate resin, and the arylate resin usable in the present invention is a random copolymer of terephthalate and isophthalate. It is desirable

The arylate according to the present invention is characterized in that it comprises 10 to 40% by weight relative to the total weight of the composition. If the content is less than 10% by weight, the expression of scratch resistance is not sufficient, and if the content is more than 40% by weight, productivity is lowered due to an increase in viscosity. In addition, the highly scratch resistant polycarbonate resin composition of the present invention includes an epoxy functional chain extender.

The epoxy functional chain extender used in the present invention may be used without particular limitation as long as the epoxy group has a function of extending the chain of the polymer, and preferably, the number of epoxy functional groups substituted with the chain extender is 3 ~. 9 can be used. As a specific example of the chain extender usable in the present invention, a block copolymer including repeating units formed by polymerization of a styrene monomer, an acrylic acid monomer and an epoxy monomer may be used, and as a specific example, a styrene-acryl-epoxy block A chain extender having a structure of a copolymer may be used, but is not limited thereto.

The epoxy functional chain extender according to the present invention has a higher reactivity in reaction extrusion as the content of epoxy is higher. For example, the epoxy equivalent weight of the epoxy functional chain extender according to the present invention may have a content of 285 to 445 g / mol, but is not limited thereto.

Epoxy functional chain extender according to the invention is characterized in that it comprises 0.1 to 2% by weight relative to the total weight of the composition. If the content is less than 0.1% by weight, the effect of the reaction extrusion is insignificant. If the content is more than 2% by weight, haze occurs in the transparent product, and die-swell phenomenon occurs seriously during the extrusion process, resulting in a sharp drop in productivity. .

In addition, optionally the high scratch resistance polycarbonate resin composition of the present invention may further comprise a phenolic antioxidant in 0.1 to 0.3% by weight relative to the total weight of the composition. In the reaction extrusion process, the hydroxyl group of the phenolic antioxidant may react with the epoxy group to improve physical properties of the resin composition. Preferably, diphenol-based antioxidants can be effectively used, for example, a diphenol-based antioxidant substituted with an alkane monomer having 1 to 5 carbon atoms in a functional group and substituted with at least one t-butyl monomer. Can be.

In addition, the high scratch resistance polycarbonate resin composition of the present invention may further include an additive generally used in the thermoplastic resin within a range without departing from the object and effect of the present invention. For example, it may further include 1 to 5% by weight of one or more additives selected from thermal stabilizers, antioxidants, lubricants, carbon black master batches or lubricants, but is not limited thereto.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

Example 1

79% by weight of polycarbonate resin, 20% by weight of arylate resin and 1% by weight of epoxy functional chain extender were subjected to reaction extrusion using a twin screw extruder. At this time, the temperature in the twin screw extruder was adjusted to 170 to 300 ° C., screw rpm to 200 rpm, and residence time to 20 to 40 seconds.

Example 2

A resin composition was obtained in the same manner as in Example 1 except that 69% by weight of polycarbonate and 30% by weight of polyarylate were used.

Comparative Example 1

A resin composition was obtained in the same manner as in Example 1 except that no polyarylate and chain extender were used.

Comparative Example 2

Except not using a chain extender, a resin composition was obtained in the same manner as in Example 1.

Comparative Examples 3-4

A resin composition was obtained in the same manner as in Example 1 except for changing the screw rotation speed of the twin screw extruder (Comparative Example 3: 100 rpm, Comparative Example 4: 400 rpm).

The composition of each component used in Examples 1 to 2 and Comparative Examples 1 to 4 and the screw rotation speed of the twin screw extruder are summarized in Table 1 below, and each component used in Examples and Comparative Examples is as follows.

(1) polycarbonate resin: polycarbonate resin polymerized by melt polymerization method

(2) arylate resin: Unitica arylate resin

(3) Epoxy functional chain extenders: BASF ADR4367

Melt-PC
(weight%) Arylate resin
(weight%) Epoxy Functional Chain Extenders
(weight%) Screw (rpm) Shear stress
(kgf / cm2) Example 1 79% 20% One% 200 150 Example 2 69% 30% One% 200 150 Comparative Example 1 100% - - 200 150 Comparative Example 2 80% 20% - 200 150 Comparative Example 3 79% 20% One% 100 62 Comparative Example 4 79% 20% One% 400 250

Test Example

The compositions of Examples 1 and 2 and Comparative Examples 1 and 4 were mixed and extruded using the twin screw extruder under the composition and extrusion conditions shown in Table 1 below, followed by injection molding after drying at 120 ° C. for 4 hours.

The surface hardness, tensile properties, impact strength, permeability and appearance characteristics of the specimens prepared according to Examples 1 to 2 and Comparative Examples 1 to 4 were measured by the following methods, and the results are shown in Table 2.

(1) Surface hardness: measured at 0.5kgf in accordance with ASTM D3363.

(2) Tensile property: Measured according to ASTM D638. (Sample Type-4)

(3) Impact strength: measured according to ASTM D256 Method-A.

(4) Permeability: It was measured according to ASTM 1003 in a blur meter.

(5) Appearance characteristics: The surface beautifulness was visually determined in three phases: upper, middle, and lower.

Furtherance Pencil hardness Tensile Modulus
(kg _f / cm ² ) The tensile strength
(kg _f / cm ² ) Tensile elongation
(%) Izod impact strength
(1/8 inch notched)
(kg _f cm / cm) Transmittance
(%) Appearance Characteristics Example 1 H 24800 655 57 28 84 Prize Example 2 2H 26100 662 45 19 80 medium Comparative Example 1 2B 24100 650 122 75 89 Prize Comparative Example 2 B 24700 652 65 39 87 Prize Comparative Example 3 F 24600 650 68 33 85 Prize Comparative Example 4 3H 25700 671 32 18 71 Ha

As shown in Table 2, in Examples 1 and 2, where the content of the epoxy functional chain extender is constant, the content of the polycarbonate is reduced and the content of the polyarylate is increased, the pencil of the resin composition It can be seen that the hardness increases rapidly.

However, even if the same amount of arylate resin was added, the synergistic effect of pencil hardness was found to be insignificant in Comparative Example 1 and Comparative Example 2 where the epoxy functional chain extender was not used.

It can be seen from this that the epoxy functional chain extender increases the compatibility between the polycarbonate and the polyarylate and the reactivity between the respective resins, thereby causing an effective reaction in a process having an extremely limited process time called an extrusion process.

In general, when heterogeneous polymers are mixed, mechanical properties tend to drop sharply due to poor compatibility, and the measurement of mechanical properties using UTM for each test shows that the mechanical properties are insignificant and the mechanical properties are insignificant. It can be seen that the physical properties improve little by little. This is believed to be due to the synergistic effect of the reaction of each resin and the improvement of compatibility between polycarbonate and polyarylate heterogeneity by the epoxy functional chain extender.

In addition, it can be seen from the results of the screw rpm and shear stress items of Example 1 and Comparative Examples 3 to 4 in Table 2 that the hardness can be controlled by limiting the reactivity by adjusting the process conditions between reaction extrusion. In other words, it can be seen that the difference in mixing conditions causes a difference in the reactivity of the epoxy functional chain extender.

Therefore, even if the composition having the same composition can be expected that the physical properties that can be obtained by the shear stress experienced during the reaction extrusion. Shear stress can be given differently by adjusting the rotational speed of the screw in the extruder.

According to the experimental results of the above item, when low shear stress is applied as in Comparative Example 3, the dispersing and distributing effect is weak in the process of melt mixing heterogeneous resins, and as a result, overall low reactivity is obtained. , When high shear stress is applied due to the high-speed rotation of the screw as in Comparative Example 4, it is possible to give a high reactivity by increasing the mixing effect on the dispersion and distribution of heterogeneous polymer.

However, due to the high shear stress imparted by the polymer chain, productivity may be impaired by high stress on the extruder. Moreover, the temperature in the extruder barrel is increased due to the shear heating effect caused by high friction. It can be seen that it is difficult to adjust correctly. In addition, due to temperature, an environment in which thermal degradation can easily occur in a polymer chain is created, and high shear stress acts on the polymer chain, thereby causing mechanical degradation, thereby causing mechanical degradation. It can be seen that there will be a fall. And as shown in the transmittance and appearance characteristics of Table 2, it can be seen that different results in transparency due to the difference in reactivity. Basically, since the difference in refractive index between polycarbonate and polyarylate is only about 0.03, transparency is not impeded by mixing between heterogeneous species, but since new reaction has been progressed by introduction of epoxy functional chain extender, You can see that some differences have occurred. Particularly, in Comparative Example 4, the transparency of the product was greatly reduced due to the rapid reaction, and thus had an unsuitable surface state for use as an injection molded product. Due to the staining could be observed.

However, except for Comparative Example 4, all the specimens were kept transparent for visual observation, and transparency was maintained without problems for use as interior products of automotive products or exterior products of battery electronic products.

Claims (7)

60 to 89 weight percent polycarbonate; 10 to 39 weight percent polyarylate; And 0.1-2 wt% epoxy functional chain extender A high scratch resistance polycarbonate resin composition comprising a shear stress of 100 to 200 kgf / cm 2 during mixing and discharging of the composition for producing a molded article. The method of claim 1, The polycarbonate has a weight average molecular weight of 17,000 to 30,000, and a high scratch resistance polycarbonate resin composition, characterized in that polymerized by the melt polymerization method. The method of claim 1, The polyarylate is a high scratch resistance polycarbonate resin composition, characterized in that the random copolymer of terephthalate and isophthalate. The method of claim 1, The epoxy functional chain extender is a high scratch resistance polycarbonate resin composition, characterized in that the block copolymer comprising a repeating unit formed by polymerization of a styrene monomer, an acrylic acid monomer and an epoxy monomer, respectively. The method of claim 1, A high scratch resistance polycarbonate resin composition, characterized by further comprising 0.1 to 0.3% by weight of a phenol-based antioxidant. The method of claim 1, A high scratch resistant polycarbonate resin composition, which is used for injection molding or extrusion molding. The molded article manufactured using the said high scratch resistance polycarbonate resin composition in any one of Claims 1-6.