KR101712419B1 - Composite sheet having excellent weather-ability - Google Patents

Abstract

The present invention relates to a multilayered composite sheet which is molded via coextrusion. More specifically, provided is a weatherproof composite sheet which is hardly discolored without reduction in physical properties even after long-term external exposure. To this end, the weatherproof composite sheet comprises: a base material layer made of an acrylonitrile-butadiene-styrene (ABS) resin; and a surface layer containing an acrylate-styrene-acrylonitrile (ASA) resin and poly(alkyl methacrylate).

Description

[0001] COMPOSITE SHEET HAVING EXCELLENT WEATHER-ABILITY [0002]

The present invention relates to a composite sheet excellent in weather resistance.

Acrylonitrile-butadiene-styrene (ABS) resin has been mainly used for a product exposed to the outside for a long time, for example, a building exterior material or an automobile exterior part. However, And the like. Polymethylmethacrylate (PMMA) resin and polycarbonate (PC) resin may be used as the resin to be applied to the molded article for exterior material. However, PMMA has excellent weather resistance but low impact resistance, and PC The impact resistance is strong but the weather resistance is somewhat insufficient and the price is high, which limits the use.

Accordingly, multilayer sheets using PMMA / ABS resin, PC / ABS resin, etc. have been developed in combination with ABS resins, PC resins, and PMMA resins, respectively, in combination.

US Patent No. 4,731,213, JP-A-1987-113527, and JP-A-1990-0003824 disclose pneumatic depressions of a PMMA resin and an ABS resin. European Patent No. 283,861 discloses an ABS resin and a PMMA resin or A pneumatic depression of a PC resin is disclosed. U.S. Patent No. 5,069,851 and JP-A No. 1993-501388 disclose laminated sheets of PMMA resin and ABS resin, respectively.

However, they have difficulties in the extrusion process due to the lack of bonding force due to the difference in compatibility between the respective resins and the instability of the interface due to the difference in fluidity. Accordingly, there is a limitation in the use of the resin, and the peeling strength, weather resistance, impact strength, There is a limit to the implementation of mechanical properties such as castability.

Korean Patent Publication No. 1990-0003824 (1990.08.27)

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a multilayer composite sheet excellent in weatherability molded by coextrusion. Specifically, the object of the present invention is to provide a weather resistant composite sheet comprising a substrate layer and a surface layer, and capable of realizing the inherent physical properties of the resin without deteriorating physical properties or discoloring upon exposure to the outside for a long period of time.

It is another object of the present invention to provide a weather resistant composite sheet capable of improving not only weather resistance but also mechanical properties such as hardness, impact strength and scratch resistance.

To achieve these and other advantages and in accordance with the purpose of the present invention,

A substrate layer made of an acrylonitrile-butadiene-styrene (ABS) resin,

And a surface layer which is an outer layer of the base layer is formed of a composition containing an acrylate-styrene-acrylonitrile (ASA) resin.

In the weather resistant composite sheet according to an embodiment of the present invention, the surface layer may further include a polyalkyl (meth) acrylate. At this time, the surface layer may contain 0.1 to 10% by weight of polyalkyl (meth) acrylate.

In the weather-resistant composite sheet according to an embodiment of the present invention, the surface layer may be 1 to 20% of the total thickness of the composite sheet.

In the weather resistant composite sheet according to an embodiment of the present invention, the surface layer is formed from a group consisting of a light stabilizer, an antioxidant, a filler, a lubricant, an impact modifier, a dye, a pigment, a flame retardant, a filler, an antibacterial agent, a releasing agent, a plasticizer and an antistatic agent And may further include any one or more selected additives.

In addition,

(a) feeding an acrylate-styrene-acrylonitrile (ASA) resin and an acrylonitrile-butadiene-styrene (ABS) resin into a feed block of an extruder maintained above the melt temperature of each resin; and

(b) preparing a weather-resistant composite sheet comprising a base layer composed of an acrylonitrile-butadiene-styrene (ABS) resin and a surface layer containing an acrylate-styrene-acrylonitrile (ASA) ≪ / RTI >

In the method for producing a weather resistant composite sheet according to an embodiment of the present invention, the surface layer may be formed by further including a polyalkyl (meth) acrylate in an acrylate-styrene-acrylonitrile resin. At this time, the surface layer may contain 0.1 to 10% by weight of polyalkyl (meth) acrylate.

A method of manufacturing a weather-resistant composite sheet according to one embodiment of the present invention, each of the resin constituting the (b) during the co-extrusion step in the base layer and the surface layer is the shear rate in the range of melting temperature from 10 to 1,000sec ^{- 1} and the viscosity ratio is 2: 1 or less.

In the method for producing a weather resistant composite sheet according to an embodiment of the present invention, in the step (b), each resin constituting the base layer and the surface layer in the co-extrusion may have a relative temperature difference within 20 ° C Lt; / RTI >

In the method for producing a weather resistant composite sheet according to an embodiment of the present invention, the surface layer may be 1 to 20% of the total composite sheet thickness.

The weather-resistant composite sheet according to the present invention is excellent in interfacial adhesion with the ABS substrate layer by including a surface layer containing an ASA resin, and is excellent in peel strength and improves not only weather resistance but also mechanical properties such as hardness, impact strength and scratch resistance So that it can be advantageously used in various industries such as building exterior materials and automobile exterior parts.

1 schematically shows a weather-resistant composite sheet according to an embodiment of the present invention.

Hereinafter, the weather-resistant composite sheet of the present invention will be described in detail. The present invention may be better understood by the following examples, which are for the purpose of illustration only and are not intended to limit the scope of protection defined by the appended claims. The technical terms and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs, unless otherwise defined.

The weather-resistant composite sheet exemplified in the present invention is a multilayer composite sheet, and includes a base layer made of an acrylonitrile-butadiene-styrene (ABS) resin and a surface layer containing an acrylate-styrene-acrylonitrile (ASA) resin . In one embodiment, the weather-resistant composite sheet according to the present invention may be ASA / ABS / ASA, but is not limited thereto, and may be a two-layered or three-layered multilayer composite sheet made of a resin composition containing an ASA Lt; / RTI >

The weather resistant composite sheet according to the present invention is laminated by coextrusion, and is characterized in that the ABS resin is formed as a base layer and the surface layer is formed of a resin composition containing an ASA resin. This can compensate for the ABS resin having disadvantages such as deterioration of physical properties with time or discoloration. In introducing another resin to realize more excellent physical properties, it is possible to improve the compatibility between the resins, By controlling the flowability of the resin to be similar to each other, the peeling strength at the interlayer interface is improved, coextrusion is smooth, and the physical properties of the resin are realized to realize a synergistic effect.

Hereinafter, the present invention will be described in detail.

The weather-resistant composite sheet according to the present invention is a multi-layer composite sheet comprising a base layer and a surface layer forming an outer layer of the composite sheet. One aspect of the present invention can be a multi-layer composite sheet 100 composed of a surface layer 10 / a base layer 20 / a surface layer 30 as shown in FIG. 1, It may further comprise a functional layer between the base layer and the surface layer. That is, the weather resistant composite sheet according to the present invention may be a two-layer or three-layer or more multi-layer composite sheet.

The weather-resistant composite sheet of the present invention can be formed as an outer layer, a surface layer containing an acrylate-styrene-acrylonitrile (ASA) resin, and laminated on both sides of a substrate layer made of an ABS resin as an inner layer to form a multilayer composite sheet . At this time, the surface layer may be 1 to 20%, preferably 2 to 15% of the total thickness of the composite sheet. When the above range is satisfied, a flow mark is not generated in the extrusion, and the surface property is excellent, which is more preferable.

The ABS resin constituting the substrate layer which is the inner layer of the composite sheet of the present invention is a copolymer composed of butadiene, styrene and acrylonitrile, and may be a diene rubber such as polybutadiene, butadiene-styrene copolymer , A butadiene-acrylic copolymer, and the like. The graft copolymer is obtained by polymerizing an aromatic vinyl compound and a vinyl cyanide compound.

The aromatic vinyl compound may be at least one selected from the group consisting of styrene, C1-C10 alkyl-substituted styrene, halogen-substituted styrene, vinyltoluene, vinylnaphthalene, and combinations thereof. Specific examples of the alkyl-substituted styrene include? -Methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, pt-butylstyrene and 2,4-dimethylstyrene. The vinyl cyanide compound may be at least one selected from acrylonitrile, methacrylonitrile, ethacrylonitrile, and combinations thereof.

The base layer of the ABS resin improves the mechanical strength such as impact resistance in combination with other layers in the composite sheet, and can realize excellent molding processability.

In the present invention, the ABS resin may have a weight average molecular weight of 10,000 to 300,000 g / mol, preferably 20,000 to 200,000 g / mol, more preferably 30,000 to 100,000 g / mol. The thermal properties are excellent and the processability can be improved, which is more preferable.

On the other hand, the ABS resin is decomposed by oxygen, ozone, light and the like in the air such that the alpha-position hydrogen dissociation energy of the double bonds in butadiene is low and easily dissociated to light, so that the physical properties may be deteriorated and discoloration may occur.

Accordingly, the present invention relates to a surface layer formed on the outer layer so that a synergistic effect of not only weatherability but also excellent mechanical properties can be achieved over the entire composite sheet while compensating for the disadvantages of the base layer in combination with the base layer made of the ABS resin, - acrylonitrile (ASA). ≪ / RTI >

The acrylate-styrene-acrylonitrile (ASA) resin is not easily discolored by using an acrylic rubber having no double bond in place of butadiene, and can prevent deterioration of physical properties due to light. In addition, it has a molecular structure in which internal deterioration hardly occurs, and weather resistance can be ensured. This can maintain the physical properties of the molded article exposed to the outside for a long period of time and prevent the appearance from being changed. Furthermore, impact resistance can be imparted by using acrylic rubber, and deterioration in colorability due to difference in refractive index between acrylic rubber and SAN (styrene-acrylonitrile) matrix resin can be prevented, and excellent coloring property can be realized.

The ASA resin may be prepared by preparing an acrylic rubber by emulsion polymerization and then graft-polymerizing styrene and acrylonitrile, though there is no particular limitation on the polymerization method.

In the present invention, it is important that the surface layer is formed on the outermost layer of the composite sheet and directly exposed to the outside to have excellent weatherability and mechanical properties as well as excellent appearance properties. To this end, the surface layer is formed of a composition comprising an ASA resin.

Furthermore, the surface layer according to the present invention may further comprise a polyalkyl (meth) acrylate, wherein the composition comprising the ASA resin. This is because the impact resistance and gloss are imparted to the composite sheet and the compatibility and chemical resistance can be improved by combination with ASA. Particularly, the polyalkyl (meth) acrylate is more preferable because it can maximize compatibility with the ASA resin and realize a property-enhancing effect.

The polyalkyl (meth) acrylate can be produced by a conventional polymerization method such as a suspension polymerization method, a bulk polymerization method, an emulsion polymerization method, and the like, but is not limited to, the raw monomer containing alkyl (meth) acrylate. The alkyl (meth) acrylate monomer may be a C1 (meth) acrylate such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, glycidyl (meth) acrylate, Lt; RTI ID = 0.0 > C10 < / RTI >

The polyalkyl (meth) acrylate may have a weight average molecular weight of 10,000 to 200,000 g / mol, and preferably 15,000 to 150,000 g / mol. When the above-mentioned range is satisfied, the ASA resin composition has good compatibility and can exhibit a property-enhancing effect.

At this time, the content of the polyalkyl (meth) acrylate contained in the ASA resin composition constituting the surface layer may be 0.1 to 10% by weight, preferably 0.5 to 8% by weight. More preferably 1 to 8% by weight. When the above range is satisfied, the compatibility with the ASA resin is maximized to improve the peel strength, and furthermore, the mechanical properties such as hardness and weather resistance as well as a synergistic effect of scratch resistance and impact resistance can be realized.

The ASA resin composition constituting the surface layer may further contain at least one selected from the group consisting of light stabilizers, antioxidants, fillers, lubricants, impact modifiers, dyes, pigments, flame retardants, fillers, antibacterial agents, mold release agents, plasticizers, And may further include additives. At this time, a benzotriazole light stabilizer may be used as the light stabilizer. As a preferable light stabilizer, commercially available products of the Tinuvin series can be used. As a more preferable example, the use of Tinuvin (R) 1600 of BASF can exhibit a synergistic effect with compatibility with the ASA resin of the surface layer, Is added to the surface layer formed on the substrate.

In the present invention, the surface layer may be 1 to 20% of the total thickness of the composite sheet, preferably 1 to 15%. When the above-mentioned range is satisfied, good interface stability and adhesion to other layers can be obtained, and excellent appearance characteristics such as weather resistance and impact resistance can be obtained. At this time, when an ASA resin composition containing polyalkyl (meth) acrylate is used as the surface layer, the thickness of the surface layer can be further reduced. That is, the surface layer formed of the ASA resin composition containing the polyalkyl (meth) acrylate in the surface layer is 1 to 15% by weight of the total thickness of the composite sheet. Therefore, excellent physical properties can be realized even if the thickness is made thinner, On the side is even better.

(A) feeding an acrylate-styrene-acrylonitrile (ASA) resin and an acrylonitrile-butadiene-styrene (ABS) resin to the feed block of an extruder maintained above the melting temperature of each resin; and A method for producing a weatherproof composite sheet comprising the steps of: (a) laminating a base layer made of an acrylonitrile-butadiene-styrene (ABS) resin and a surface layer containing an acrylate-styrene-acrylonitrile (ASA) .

In one embodiment of the weather resistant composite sheet of the present invention, the ASA resin composition and the ABS resin in a molten state in the feed block are adjusted to have an appropriate temperature difference, and these resins are joined to form a shear rate range of 10 to 1,000 seconds ^-1 . ≪ / RTI > In this case, the viscosity ratio in the shear rate range is preferably 1: 1 to 2: 1. The temperature difference between the ASA resin composition and the ABS resin may preferably be 20 ° C or less. If the temperature difference and the shear rate range are satisfied, the extrusion fluidity can be smooth and the moldability is excellent. Can be prevented.

The extruding speed of the extruder may be 20 to 100 rpm when the composite sheet of the present invention is manufactured, and the multilayer structure can be adjusted by the relative ratio of the extruded amount. At this time, the temperature of the roller may be in the range of 50 to 100 캜. If the temperature is lower than 50 캜, the orientation of the resin becomes severe due to the rapid cooling, and if it exceeds 100 캜, the resin sticks to the roller.

The composite sheet of the present invention can be produced by co-extruding an ASA resin composition as a base layer with ABS resin as a base layer, thereby having an excellent adhesive force at the interface and having excellent peel strength, and particularly excellent weatherability, impact resistance, Can be implemented. This improves the adhesion at the interface so as not to cause layer separation, and it can improve not only excellent weatherability but also mechanical properties such as hardness, impact strength, scratch resistance, and the like, Field.

Hereinafter, an example of the weather-resistant composite sheet according to the present invention will be described. However, the present invention is not limited to the following examples.

(Example 1)

Acrylate-styrene-acrylonitrile (ASA) resin (average particle diameter: 0.3 mu m, containing 40 wt% of butyl acrylate, weight average molecular weight: 150,000 g / mol) , And an ABS resin (weight average molecular weight: 40,000 g / mol) was used as the substrate layer. These resins were placed in an extruder and coextruded through interlocked feedblocks. In the setting of the melting temperature in the extruder, the temperature difference between the ASA resin constituting the surface layer and the ABS resin constituting the substrate layer was controlled to be 20 ° C, and the resin bonded by the ASA / ABS / ASA structure was sent to the die at the downstream end, . The extruder used for the ABS resin was an extruder having a diameter of 120 mm, a screw of 40 L / D (36 rpm), an ASA resin extruder of 60 mm diameter and a screw of 25 L / D (25 rpm) Respectively. The die temperature was adjusted to 200 ° C according to the flow of the resin, and the temperature of the polishing roller was adjusted to 80 ° C. The thickness of the composite sheet thus produced was 10 mm, and the thickness of the surface layer was 10% of the total thickness. The properties of the composite sheet were measured and are shown in Table 1 below.

(Example 2)

Except that an ASA resin composition consisting of 95% by weight of the ASA resin used in Example 1 and 5% by weight of polymethyl methacrylate (PMMA) (Altuglas V040, Acme Co., Ltd.) was used as the surface layer Respectively.

(Example 3)

Except that an ASA resin composition consisting of 90 wt% of the ASA resin used in Example 1 and 10 wt% of polymethyl methacrylate (PMMA) was used as the surface layer.

(Example 4)

Except that an ASA resin composition consisting of 99.9% by weight of the ASA resin used in Example 1 and 0.1% by weight of polymethyl methacrylate (PMMA) was used as the surface layer.

(Example 5)

Except that an ASA resin composition consisting of 99.95 wt% of the ASA resin used in Example 1 and 0.05 wt% of polymethyl methacrylate (PMMA) was used as the surface layer.

(Example 6)

The same procedure as in Example 1 was carried out except that an ASA resin composition consisting of 89 wt% of the ASA resin and 11 wt% of polymethyl methacrylate (PMMA) used in Example 1 was used as the surface layer.

(Example 7)

And the surface layer was changed to 15% of the total thickness of the composite sheet.

(Example 8)

The surface layer was changed to be 22% of the total thickness of the composite sheet.

(Example 9)

The same procedure as in Example 1 was carried out except that the surface layer was changed to be 0.5% of the total thickness of the composite sheet.

(Comparative Example 1)

The procedure of Example 1 was repeated except that polymethyl methacrylate (PMMA) used in Example 2 was used instead of ASA resin as the surface layer.

(Comparative Example 2)

Except that polycarbonate (PC) (weight average molecular weight: 30,000 g / mol) was used instead of ASA resin as the surface layer.

(evaluation)

(1) FDI (Falling Dart Impact) Impact Strength (Unit: J)

Using a weight of 2 kg, the height was adjusted and dropped onto a 1 mm thick specimen to visually confirm whether the specimen cracked or not, and the maximum height at which no crack occurred was measured. The falling dart impact (FDI) of 2 mm thick specimens (10 cm × 10 cm × 2 mm) measured using a 2 kg dart, based on the Dupont drop measurement, (Crack generation energy value) was measured.

(2) Chemical resistance (unit: hour)

A tensile specimen for the measurement of ASTM D638 was fixed to a jig and a Nanox detergent manufactured by LION Japan Co., Ltd. was applied according to ESCR test (see SPE Journal (p667 ~ 670), June, 1962) Were measured for 72 hours. When no crack occurred, the mark was marked with & cir & and when the crack occurred, the time at that point was described.

(3) scratch resistance

Based on the pencil hardness measured under conditions of 500 g load in accordance with ASTM D3362 standard. For reference, the scratch resistance according to the pencil hardness grade class is excellent as the H value is high, and as the B value is high, the scratch resistance means the heat loss.

(5H> 4H> 3H> 2H> HB> 2B> 3B> 4B> 5B> 6B)

(4) Ultraviolet (UV) stability

Irradiance: 0.35 W / m < 2 > / 340 nm, Irradiation Cycle: 102 min / Light, 18 min (Light Temperature: 63 deg. C, Relative Humidity: 50%, Irradiance: 0.35 W / / Light + Spray) (Model Ci65A) for 2,400 hours, and the degree of discoloration was measured as? E.

(5) Tensile strength

And measured according to the ISO 527 standard (50 mm / min).

[Table 1]

As can be seen from the above Table 1, Examples 1 to 4 and 7 according to the present invention confirmed that the mechanical properties of excellent tensile strength, including high impact strength and scratch resistance, were improved, and furthermore, excellent weatherability was achieved. In Examples 5 and 6, the PMMA resin content in the ASA resin composition constituting the surface layer was 0.05 wt% and 11 wt%, respectively, and the chemical resistance was slightly lowered. However, the weather resistance, hardness and tensile strength were good, And 9 show that the thickness of the surface layer was controlled to be 22% and 0.5% of the total sheet thickness, respectively, and the tensile strength was somewhat lowered or the chemical resistance was lowered. On the other hand, in Comparative Example 1, the pencil hardness and tensile strength were good, but the impact strength and weatherability were significantly lowered, and the chemical resistance was somewhat lowered. In Comparative Example 2, although the impact strength was maintained to a certain extent, it was insufficient in Examples, and the hardness, chemical resistance and weather resistance were deteriorated.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Various modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

100: composite sheet, 10: surface layer
20: base layer, 30: surface layer

Claims (11)

A base layer made of an acrylonitrile-butadiene-styrene (ABS) resin and
Acrylate-styrene-acrylonitrile (ASA) resin and a surface layer containing polyalkyl (meth) acrylate,
Wherein the surface layer contains 0.1 to 10% by weight of polyalkyl (meth) acrylate.
delete delete The method according to claim 1,
Wherein the surface layer is 1 to 20% of the total thickness of the composite sheet.
The method according to claim 1,
Wherein the surface layer further comprises at least one additive selected from the group consisting of a light stabilizer, an antioxidant, a filler, a lubricant, an impact modifier, a dye, a pigment, a flame retardant, a filler, an antibacterial agent, a releasing agent, a plasticizer and an antistatic agent.
(a) an acrylate-styrene-acrylonitrile (ASA) resin, a polyalkyl (meth) acrylate and an acrylonitrile-butadiene-styrene (ABS) resin as feedblocks of an extruder maintained above the melting temperature of each resin And
(b) a base layer composed of an acrylonitrile-butadiene-styrene (ABS) resin and a surface layer containing an acrylate-styrene-acrylonitrile (ASA) resin and a polyalkyl (meth) step
, ≪ / RTI &
Wherein the surface layer contains 0.1 to 10% by weight of polyalkyl (meth) acrylate.
delete delete The method according to claim 6,
Wherein each resin constituting the substrate layer and the surface layer in co-extrusion in the step (b) has a shear rate at a melting temperature of 10 to 1,000 sec ^-1 and a viscosity ratio of 2: 1 or less.
The method according to claim 6,
Wherein each resin constituting the base layer and the surface layer in co-extrusion in the step (b) has a relative temperature difference within 20 ° C when mixed in the feed block.
The method according to claim 6,
Wherein the surface layer is 1 to 20% of the total thickness of the composite sheet.

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