KR101993703B1 - Composite sheet - Google Patents

Abstract

The present invention relates to a composite sheet and, more specifically, to a composite sheet comprising a polycarbonate resin layer and an acrylic resin layer formed on one side or both sides of the polycarbonate resin layer, and having remarkably improved physical properties such as impact resistance, scratch resistance, weather resistance, chemical resistance, and the like while having optical properties such as excellent transparency.

Description

Composite Sheet {COMPOSITE SHEET}

The present invention relates to a composite sheet. More specifically, the present invention relates to a polycarbonate resin composition comprising a polycarbonate resin layer and an acrylic resin layer formed on one or both sides of the polycarbonate resin layer and exhibiting not only excellent optical properties such as transparency but also remarkably improved physical properties such as impact resistance, scratch resistance, weather resistance, Sheet.

In the automobile industry, weight reduction is important in terms of securing competitiveness such as improving fuel efficiency and cost reduction. The use of transparent plastic glazing parts has been increasing in place of glass applied to sunroofs and the like in order to provide lightness, openness and aesthetics. Polycarbonate resins are widely used as transparent plastic glazing parts.

The polycarbonate resin is excellent in strength and transparency and is widely used as a means for replacing glass in various fields. Korean Patent No. 10-1352534 discloses that a transparent plastic substrate made of a polycarbonate resin is applied to plastic for automobile glass.

However, the polycarbonate resin has problems that the surface can be easily damaged, the impact resistance, the low-temperature impact resistance, the chemical resistance are poor, and the color is deteriorated or the physical properties are deteriorated when exposed to the outside for a long time. To solve this problem, there have been developed methods using a resin composition in which a polycarbonate resin is mixed with another resin, but there have been limitations in improving physical properties.

Therefore, it is necessary to develop a technology that can be applied to various fields as a transparent plastic glazing component in order to overcome such disadvantages.

Korean Patent No. 10-1352534 (Jan. 10, 2014)

An object of the present invention is to provide a polycarbonate resin composition which is obtained by laminating an acrylic resin layer on one side or both sides of a polycarbonate resin layer so as to secure not only excellent mechanical and optical properties of a polycarbonate resin for a long period of time, It is an object of the present invention to provide a composite sheet having remarkably improved impact resistance, low temperature impact resistance, scratch resistance and durability.

Another object of the present invention is to provide a composite sheet having high light transmittance and excellent light diffusibility, which effectively shields external light while exhibiting excellent visibility and excellent anti-fogging properties.

Another object of the present invention is to provide a composite sheet excellent in weather resistance, chemical resistance and chemical resistance.

Another object of the present invention is to provide a plastic glazing component which can satisfy a wide range of physical properties and thus can expand its application range including automotive exterior materials such as sunroof.

In order to accomplish the above object, one aspect of the present invention is a method of manufacturing a polycarbonate resin composition comprising a polycarbonate resin layer containing light diffusion particles and an acrylic resin layer formed on one or both sides of the polycarbonate resin layer using an acrylic resin composition Sheet.

In the composite sheet according to an embodiment of the present invention, the acrylic resin composition may include a polymer derived from a methyl methacrylate monomer.

In the composite sheet according to an embodiment of the present invention, the light diffusion particles may have an average particle size of preferably 0.001 to 20 μm.

In the composite sheet according to one embodiment of the present invention, the light-diffusing particle is at least one inorganic particle selected from calcium carbonate, barium sulfate, titanium dioxide, aluminum hydroxide, silica, talc, mica, magnesium oxide, . ≪ / RTI >

In the composite sheet according to one embodiment of the present invention, the polycarbonate resin layer may have a weight average molecular weight of 10,000 to 500,000 g / mol.

In the composite sheet according to one embodiment of the present invention, the acrylic resin composition may be an ethylene-acrylic acid copolymer, an ethylene-methacrylic acid copolymer, an ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, Acrylate copolymer and an ethylene-vinyl acetate copolymer, and the like.

In the composite sheet according to one embodiment of the present invention, the acrylic resin layer may have a thickness of 1 to 25%, as compared to the polycarbonate resin layer.

In the composite sheet according to an embodiment of the present invention, the acrylic resin composition may further include at least one additive consisting of a UV stabilizer, an antistatic agent, an antioxidant, a heat stabilizer, a lubricant, a filler, and a colorant.

Another aspect of the present invention relates to an automotive exterior material comprising the composite sheet described above.

The composite sheet according to the present invention has remarkably improved mechanical properties including impact resistance, low temperature impact resistance and scratch resistance, and has an effect of ensuring excellent durability.

In addition, it has high light transmittance and excellent light diffusing property, so it has an effect of securing a cool open feeling and visibility while effectively blocking external light when applied to glass replacement means such as a sunroof.

Further, it has an effect of significantly improving weatherability and chemical resistance.

Hereinafter, the composite sheet of the present invention will be described in detail. The invention can be better understood by the following examples. The following examples are for illustrative purposes 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 terms used in the description of the present invention are merely for the purpose of effectively describing certain embodiments. It is also to be understood that the singular forms as used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The inventors of the present invention have intensively studied plastic glazing products as means for replacing glass, and have found that by providing a polycarbonate resin layer and a composite sheet of an acrylic resin layer formed on one side or both sides thereof, mechanical properties such as impact resistance It is possible to remarkably improve not only high light transmittance but also excellent light diffusing property and anti-fogging property so that it can realize excellent physical properties when applied to automobile exterior materials such as sunroof, and furthermore it is excellent in weatherability and chemical resistance, The present invention has been completed.

Hereinafter, the composite sheet according to the present invention will be described in detail.

The present invention provides a composite sheet comprising a polycarbonate resin layer containing light diffusing particles and an acrylic resin layer formed on one or both sides of the polycarbonate resin layer using an acrylic resin composition.

The polycarbonate resin layer is formed by a polycarbonate resin composition containing light diffusing particles. The polycarbonate resin may be one prepared by a known method, for example, bisphenol A and phosgene. However, the polycarbonate resin is not limited thereto.

The weight average molecular weight of the polycarbonate resin is not particularly limited, but may be 10,000 to 500,000 g / mol, preferably 20,000 to 200,000 g / mol. Within the above range, it is more effective in improving the desired mechanical and optical properties as well as in sheet form molding.

According to one aspect of the present invention, the polycarbonate resin may be used by mixing two or more kinds of resins having different molecular weights. Preferably a first polycarbonate resin having a weight average molecular weight of 10,000 to 100,000 g / mol and a second polycarbonate resin having a molecular weight larger than that of the first polycarbonate resin, preferably 30,000 g / mol or more, more preferably 50,000 g / mol of the second polycarbonate resin having a difference in molecular weight is effectively used because it realizes a uniform improvement over the desired physical properties by effectively preventing the deterioration of the physical properties due to the pressure or the temperature generated in the molding process , Which is a non-limiting example only, and is not limited to the above numerical range.

The weight average molecular weight was measured by gel permeation chromatography (GPC) using a sample dissolved in tetrahydrofuran (THF). The analytical column was Styragel HR manufactured by WATERS Co., and the standard material was polystyrene (PS) .

According to one embodiment of the present invention, the polycarbonate resin composition has a remarkable effect of improving mechanical properties such as impact resistance, particularly low temperature impact properties, as well as improved optical properties as glass substitute means by including light diffusing particles.

The type of the light-diffusing particles is not particularly limited, but it is more preferable to use the inorganic particles than the organic particles to achieve the object of the present invention. Examples of the inorganic particles include any one or a mixture of two or more selected from the group consisting of calcium carbonate, barium sulfate, titanium dioxide, aluminum hydroxide, silica, talc, mica, magnesium oxide and zinc oxide. It is not.

The average particle diameter of the light-diffusing particles is not particularly limited, but may be 0.001 to 20 탆, preferably 0.1 to 10 탆. In view of dispersibility and good optical properties within the above-mentioned range and securing excellent mechanical properties, it is preferable to use a non-limiting example.

The content of the light-diffusing particles may be controlled within a range that does not impair the object of the present invention, but is preferably 0.1 to 20 parts by weight, more preferably 0.2 to 20 parts by weight, per 100 parts by weight of the polycarbonate resin. 10 parts by weight.

The polycarbonate resin composition may contain various additives usually used in the range not hindering the object of the present invention, for example, an antioxidant, a UV stabilizer, a flame retardant, an antistatic agent, and the like.

The ultraviolet stabilizer may be preferred not only to prevent deterioration of the physical properties of the resin composition itself due to ultraviolet rays and aging of the final molded product, but also to realize a synergistic effect of physical properties in combination with other components in the composition.

Examples of the ultraviolet stabilizer include benzotriazole, benzophenone, hindered amine light stabilizer (HALS), triazine, and the like. But it is not necessarily limited thereto. It is more preferable to use a HALS compound.

According to one aspect of the present invention, the composite sheet includes an acrylic resin layer formed on one side or both sides of the polycarbonate resin layer. The combination of the lamination components of the polycarbonate resin layer and the acrylic resin layer effectively improves long-term physical stability of the polycarbonate resin layer, while remarkably improving mechanical properties such as impact resistance and low-temperature impact resistance as well as weather resistance, durability, It is very effective in enhancing sex.

The acrylic resin layer is formed by an acrylic resin composition containing a polymer derived from a methyl methacrylate monomer. And may preferably be polymethyl methacrylate.

The weight average molecular weight of the polymethylmethacrylate is not particularly limited within the range not impairing the object of the present invention, but may be 10,000 to 200,000 g / mol, preferably 50,000 to 150,000 g / mol. It is more effective in terms of securing an improved impact resistance in a wide temperature range including an extremely low temperature of less than or equal to zero within the above range and further ensuring scratch resistance, weather resistance and chemical resistance, It is to be understood that the invention is not limited to the above-described numerical ranges.

According to one embodiment of the present invention, the acrylic resin composition further comprises an ethylene copolymer composed of ethylene and at least one monomer selected from (meth) acrylic acid monomer, (meth) acrylate and vinyl acetate, A remarkably improved effect can be realized.

Specifically, the ethylene copolymer is an ethylene-acrylic acid copolymer (EAA), an ethylene-methacrylic acid copolymer (EMAA), an ethylene-methyl acrylate copolymer (EMA), an ethylene-ethyl acrylate copolymer (EEA) -Butylacrylate copolymer (EBA), an ethylene-vinyl acetate copolymer (EVA), and the like, but the present invention is not limited thereto. Preferably, the use of an ethylene-ethyl acrylate copolymer (EEA) is more effective, but not always limited thereto.

The content of the ethylene copolymer is not particularly limited, but may be 0.1 to 5 parts by weight, specifically 0.2 to 3 parts by weight, more specifically 0.5 to 2 parts by weight, based on 100 parts by weight of polymethylmethacrylate. In this range, the compatibility of the components in the composition can be further enhanced, which is more effective in terms of realizing a desired property-enhancing effect. Also, it is preferred in that it can maintain superior optical properties even when exposed to extreme external conditions for a long period of time for a long time, but can realize a remarkable increase in physical properties such as impact resistance, durability, weather resistance and chemical resistance, But is not limited to the above numerical range.

The combination of the ethylene copolymer and the polycarbonate resin layer containing a mixture of polycarbonate resins different in molecular weight from each other is remarkably superior in antifogging performance even in a harsh environment with a very high humidity, And it is more effective in realizing uniform improvement over the entire property.

According to an embodiment of the present invention, the acrylic resin composition may further include a methyl (meth) acrylate copolymer in addition to polymethyl methacrylate.

Specifically, the methyl (meth) acrylate copolymer is obtained by copolymerizing a methyl (meth) acrylate monomer with a monomer selected from the group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylbutyl acrylate, Acrylates such as hexyl acrylate, heptyl acrylate, octyl acrylate, n-pentyl acrylate, vinyl acrylate, lauryl acrylate, ethyl methacrylate, butyl methacrylate, 2-ethylbutyl methacrylate, Acrylate, and lauryl methacrylate, but the present invention is not limited thereto.

The methyl (meth) acrylate copolymer may be contained in an amount of 1 to 15 parts by weight, specifically 2 to 10 parts by weight, based on 100 parts by weight of polymethyl methacrylate. Is effective in securing the optical properties in the above-mentioned range while improving the mechanical properties such as improved impact resistance and scratch resistance, but is not limited to the above numerical range.

According to one aspect of the present invention, the thickness of the composite sheet may be appropriately adjusted depending on applications, and may be specifically 0.5 to 50 mm, more specifically 1.0 to 10 mm, but is not limited thereto. At this time, the acrylic resin layer may have a thickness of 1 to 25%, specifically 2 to 20%, as compared with the polycarbonate resin layer. And is effective in securing impact resistance without lowering the physical properties in the thickness range as described above, but is not necessarily limited thereto.

The acrylic resin composition is preferably a composition comprising a UV stabilizer, an antistatic agent, an antioxidant, a heat stabilizer, a flame retardant, a light diffusing agent, a slip agent, a lubricant, a filler, a dye and a pigment in order to secure physical properties such as weather resistance and chemical resistance. Based on the total weight of the composition. The kind and content of these additives can be appropriately adjusted at a level commonly used in this field as needed, but are not limited thereto.

The composite sheet according to an embodiment of the present invention has excellent mechanical and optical properties and can be applied as a means for replacing glass. For example, it may be a transparent plastic glazing product, but is not limited thereto. It is advantageous in that it can secure long-term quality stability and reliability as an automobile exterior material.

The composite sheet can be produced by referring to a known technique. In one specific embodiment, a composite sheet in which a polycarbonate resin layer and an acrylic resin layer are laminated on both sides thereof may be produced by coextrusion. That is, a main extruder for extruding a composition for a polycarbonate resin layer, and a sub-extruder for extruding a composition for an acrylic resin layer can be used. The temperature condition of the extruder may be within a normal range, specifically, from 230 to 320 ° C, more specifically, from 250 to 290 ° C.

As a lamination method using these compositions, a known method can be used, but a feed block method can be used specifically. The molten resin laminated with the feed block is introduced into a sheet molding die such as a T-die, molded into a sheet shape, and then finished by cooling the surface with a shaping roll. At this time, the temperature of the die may be 250 to 320 ° C, specifically 270 to 300 ° C, and the temperature of the forming roll may be 100 to 180 ° C, specifically 110 to 170 ° C, but is not limited thereto.

Another aspect of the present invention can provide an automobile exterior material including the composite sheet described above. Examples of such automobile exterior materials include a sunroof, a front glass, a rear glass, a quarter glass, a front vent glass, a rear vent glass, , But is not limited thereto.

Hereinafter, the composite sheet according to the present invention will be described in more detail with reference to examples. It should be understood, however, that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

Unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Also, the singular forms as used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

(Example 1)

2 parts by weight of talc having an average particle diameter of 8 mu m was added to 100 parts by weight of a polycarbonate resin having a weight average molecular weight of 25,000 g / mol (PANLITE L-1250WP manufactured by TENJIN) to prepare a composition for a polycarbonate resin layer.

1 part by weight of an ultraviolet stabilizer (HALS series, KIMASOFU 944 (CIBA-GEIGY)) was added to 100 parts by weight of polymethyl methacrylate (PMMA, PM-7200, Cheil Industries) having a weight average molecular weight of 105,000 g / To prepare a composition for an acrylic resin layer.

The composition for the polycarbonate resin layer and the composition for the acrylic resin layer were put into respective extruders, melted and kneaded, and then fed to a feed block die to obtain a laminate structure of an acrylic resin layer / polycarbonate resin layer / acrylic resin layer Specimens were prepared. The extruder for extruding the composition for a polycarbonate resin layer had a barrel diameter of 65 mm, a screw L / D of 35 and a cylinder temperature of 280 ° C. The extruder for extruding the composition for an acrylic resin layer had a barrel diameter of 32 mm, / D = 32, and the cylinder temperature was 250 占 폚. Each layer was made to have a thickness of 500 mu m / 7,000 mu m / 500 mu m.

(Example 2)

In the composition for an acrylic resin layer of Example 1, 10 parts by weight of ethylene-ethyl acrylate (EAA; ethylene-ethylacrylate, Dupont-Mitsui Polychem, EEA A703, ethylacrylate 25 wt%) was added to 100 parts by weight of polymethyl methacrylate Was carried out in the same manner as in Example 1,

(Example 3)

A polycarbonate mixture obtained by mixing 60% by weight of a polycarbonate resin having a weight average molecular weight of 25,000 g / mol and 40% by weight of a polycarbonate having a weight average molecular weight of 150,000 g / mol was used instead of the polycarbonate resin used in Example 1 The same procedure was followed as in Example 1 except for using.

(Example 4)

A polycarbonate mixture obtained by mixing 60% by weight of a polycarbonate resin having a weight average molecular weight of 25,000 g / mol and 40% by weight of a polycarbonate having a weight average molecular weight of 150,000 g / mol was used instead of the polycarbonate resin used in Example 1 Ethylene-ethylacrylate (EAA; Dupont-Mitsui Polychem, EEA A703, ethylacrylate 25% by weight) was added to 100 parts by weight of polymethylmethacrylate in the composition for an acrylic resin layer of Example 1 10 parts by weight were further added.

(Example 5)

The procedure of Example 1 was repeated except that the composition for polycarbonate resin layer of Example 1 was changed to an average particle diameter of talc of 25 占 퐉.

(Example 6)

In Example 1, the same procedure as in Example 1 was carried out except that the laminated component thicknesses of the acrylic resin layer / polycarbonate resin layer / acrylic resin layer composite sheet were adjusted to 1,700 μm / 6,000 μm / 1,700 μm.

(Comparative Example 1)

2 parts by weight of talc having an average particle diameter of 8 μm and 100 parts by weight of a polycarbonate resin having a weight average molecular weight of 25,000 g / mol (PANLITE L-1250WP manufactured by TENJIN CORPORATION) CIBA-GEIGY Co., Ltd.)) was melted, kneaded and extruded to prepare pellets. The pellets were dried at 110 ° C for 6 hours and then injected at a temperature of 300 ° C in a 6 Oz extruder to prepare specimens having the same size as in Example 1 .

(evaluation)

(1) Impact resistance: The specimen was placed on the floor at room temperature (25 ° C), and a weight of 3 kg was dropped at a height of 0.5 m to check whether a crack occurred. ? Indicates that no crack occurred 10 times or more,? Indicates that cracks occurred at 7 to 9 times,? Indicates that cracks occurred at 2 to 6 times, and? When cracks occurred at 1 time. The specimens were allowed to stand at -50 占 폚 for 4 hours, and the impact resistance was tested in the same manner as described above.

(2) Transmittance (%): The transmittance of a specimen having a thickness of 2 mm was measured and compared using a haze meter (NIPPON DENSHOKU, YDP02-0D) according to ASTM D1003.

3, light-diffusing: of measuring a goniophotometric the acceptance angle 0 ° of the light transmission using I _0, acceptance angle 75 ° of the light transmittance I ₇₅ is the value calculated then by the formula is more than 90% ○, 75 %, ≪ / RTI > if less than 90%, and & cir &

(Formula) light diffusivity = (I ₇₅ / I ₀ ) x 100

(4) Izod Impact Strength (kgf · cm / cm): Measured using Notched specimen (1/4 ") in accordance with ASTM D256.

(5) Scratch resistance: A Ball-type Scratch Profile (BSP) test was conducted. The surface of the specimen was subjected to a scratch of a length of 20 mm using a 1000 g load and a spherical metal tip of 0.7 mm diameter at a speed of 75 mm / min. The profile of the applied scratch was measured by a contact surface profile analyzer (XP-1) Scanning was performed using a tip of a metal stylus having a thickness of 2 占 퐉, and the profile of the scratch was measured and the scratch width (占 퐉) was calculated therefrom. As the measured scratch width decreases, scratch resistance increases.

(6) Weatherability: The specimens were irradiated for 240 hours at a wavelength of 2,500 kJ / m2 using a wavelength of 340 nm, and then the surface was observed for discoloration or cracking. ? Indicates that no discoloration or cracking occurs in two pieces (less than 0.25 cm in size),? Indicates that less than ten pieces are produced, and?

(7) Chemical resistance: The surface of the specimen was rubbed and rubbed 10 times with 5N force using ethyl alcohol, and then discoloration or cracking of the surface was observed. ? Indicates that no discoloration or cracking occurs in two pieces (less than 0.25 cm in size),? Indicates that less than ten pieces are produced, and?

(8) Acid resistance: 0.1 N hydrochloric acid was dropped on the surface of the specimen at a rate of 0.1 ml, followed by standing at room temperature (25 ° C) for 24 hours, followed by washing and drying. Then, when there is no change in the surface, there is a mark ⊚, when discoloration or cracking occurs less than two pieces (less than 0.25 cm 2), ∘ when three or more pieces occur and less than 10 pieces, and when the number is more than 10 pieces.

(9) Anti-fog: The specimen was placed at a height of 5 cm from the surface of the hot water bath maintained at 80 ° C. Steam from the hot bath was continuously irradiated onto the coated film, and the presence / Respectively. ?, No blurring was observed at all,?, No blurring was observed after only a moment after steam irradiation,? When slight blurring was observed, and?

[Table 1]

As can be seen from Table 1, the examples showed excellent performance in terms of weather resistance, chemical resistance, acid resistance and anti-fogging as well as improvement of mechanical properties such as impact resistance and scratch resistance throughout physical properties. In particular, Examples 1 to 4 showed remarkable improvement in physical properties in low temperature impact resistance and anti-fogging properties, and were excellent in weather resistance and chemical resistance as well as in high transmittance and excellent scratch resistance. On the other hand, in Comparative Example 1, the impact resistance and scratch resistance were remarkably lowered as compared with the Examples, and the physical properties were not good in terms of transmittance, light diffusibility, weather resistance, chemical resistance and acid resistance.

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 .

Claims (10)

A polycarbonate resin layer containing light-diffusing particles and two kinds of polycarbonates having weight average molecular weights different from each other and having a weight average molecular weight difference of 30,000 to 100,000 g / mol, and
A) a polymer derived from a methyl methacrylate monomer, and b) a monomer selected from a (meth) acrylic acid monomer, (meth) acrylate and vinyl acetate, and a monomer derived from ethylene Ethylene copolymer and an acrylic resin composition comprising an ethylene copolymer.
delete The method according to claim 1,
Wherein the light-diffusing particles have an average particle diameter of 0.001 to 20 mu m.
The method according to claim 1,
Wherein the light-diffusing particles comprise at least one selected from the group consisting of calcium carbonate, barium sulfate, titanium dioxide, aluminum hydroxide, silica, talc, mica, magnesium oxide and zinc oxide.
The method according to claim 1,
Wherein the polycarbonate resin layer comprises two kinds of polycarbonate each independently having a weight average molecular weight of 10,000 to 500,000 g / mol.
The method according to claim 1,
The ethylene copolymer is preferably an ethylene-acrylic acid copolymer, an ethylene-methacrylic acid copolymer, an ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-butyl acrylate copolymer and an ethylene-vinyl acetate copolymer Or a combination thereof.
The method according to claim 1,
Wherein the acrylic resin layer has a thickness of 1 to 25% of the thickness of the polycarbonate resin layer.
The method according to claim 1,
Wherein the acrylic resin composition comprises at least one selected from the group consisting of an ultraviolet stabilizer, an antistatic agent, an antioxidant, a heat stabilizer, a lubricant, a filler and a colorant.
An automotive exterior member comprising any one of the composite sheets selected from Claims 1 and 3 to 8.
10. The method of claim 9,
Wherein the automotive exterior material is one selected from a sunroof, a front glass, a rear glass, a quarter glass, a front vent glass, and a rear vent glass.