KR101718225B1 - Multilayer polycarbonate sheet having good scratch resistance and weatherability - Google Patents

Abstract

A multilayer sheet for a greenhouse having a polycarbonate multilayer sheet composed of a coating layer and a substrate layer of a specific composition is used to improve scratch resistance and weather resistance without deteriorating the permeability and enhance impact resistance. The present invention relates to a coating layer comprising 43 to 89.9% by weight of a polycarbonate resin, 10 to 50% by weight of a methacrylic copolymer resin and 0.1 to 10% by weight of an ultraviolet absorber; And a base layer comprising a polycarbonate resin. The present invention also provides a green sheet multilayer polycarbonate sheet.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a multi-layer polycarbonate sheet having excellent scratch resistance and weather resistance,

The present invention relates to a green multi-layer polycarbonate sheet, and more particularly, to a green multi-layer polycarbonate sheet having excellent scratch resistance and weathering resistance.

Polycarbonate resin is excellent in impact resistance and mechanical properties, and exhibits high transparency, excellent dimensional stability, and broad coloring property. Recently, as a result of cost reduction, enlargement, and weight reduction of electric and electronic products, plastic products using polycarbonate resin The area of glass or metal material is rapidly replacing, and the range of use is expanded to electric and electronic products as well as automobile parts.

On the other hand, when a greenhouse is replaced with a plastic sheet, it can be used for a long time in comparison with a general vinyl house, and a greenhouse can be provided which is lighter than a greenhouse. In the case of conventional vinyl houses, it has a low cost advantage, but it can not be used for a long time and is vulnerable to natural disasters such as typhoons. In addition, glass greenhouses have the advantage of being able to be used for a long time, but there is a drawback in that a strong frame is required because of the inherent weight due to the high density of the glass. The demand for the development of a greenhouse by a plastic sheet was constant, but the weatherability of the glasshouse was lower than that of a glasshouse, and the surface scratch and abrasion due to a storm and a hail caused the permeability to decrease and the growth of the crop was hindered.

Japanese Patent Application Laid-Open No. 1140971 discloses a technique for raising the greenhouse effect by forming a pore with a multi-layered structure as a multi-layered vinyl sheet having a multi-layered vinyl paper in order to increase the warming effect of the greenhouse of a vinyl house, House is basically impossible to use for a long time, which causes not only environmental pollution caused by waste vinyl, but also light transmittance is lowered due to lamination and pore formation, which can cause an incense to grow crops.

Patent Publication No. 0316364 discloses a technique of using PMMA resin as a surface layer and constituting a supporting layer with an ABS / PC mixed resin as a support layer, using weather resistance performance of PMMA and impact resistance of PC / ABS, In the case of the same PC / ABS alloy, the impact resistance is deteriorated according to the ABS content, and when the content of PC is excessive, there is a restriction of the use due to the deterioration of the fluidity. In addition, the transparency deterioration due to ABS is low, which is close to opaque, and has limitations in cultivating crops.

Laid-Open Publication No. 2015-0050715 discloses a high-hardness multilayered sheet comprising a laminated structure of a polymethylmethacrylate layer and a polycarbonate layer, and discloses a technique in which hardness and physical properties are improved by using two different resins However, when co-extruded with different characteristics of PMMA and PC, the defect rate is high and the bonding force is weak and the peeling is likely to occur.

DISCLOSURE Technical Problem Accordingly, the present invention has been made to solve the above problems, and it is an object of the present invention to provide a polycarbonate multilayer sheet comprising a coating layer and a substrate layer having a specific composition, Thereby providing a multilayer sheet.

In order to solve the above problems, the present invention provides a coating layer comprising 43 to 89.9% by weight of a polycarbonate resin, 10 to 50% by weight of a methacrylic copolymer resin and 0.1 to 10% by weight of an ultraviolet absorber; And a base layer comprising a polycarbonate resin. The present invention also provides a green sheet multilayer polycarbonate sheet.

The polycarbonate resin of the coating layer and the base layer has a weight average molecular weight of 10,000 to 200,000.

Also, the methacrylic copolymer resin is a copolymer of 10 to 100% by weight of an aliphatic or aromatic methacrylate represented by the following formula (1) and 0 to 90% by weight of a monofunctional unsaturated monomer, to provide.

[Chemical Formula 1]

(Wherein m is an integer of 0 to 10, and X is a methyl group, a phenyl group, a cyclohexyl group, a methylphenyl group, a methylethylphenyl group, a propylphenyl group, a methoxyphenyl group, a cyclohexylphenyl group, a chlorophenyl group, Or a benzylphenyl group)

Also, the ultraviolet absorber is at least one selected from the group consisting of benzotriazole-based, benzophenone-based, benzotriazine-based, malonate-based and cyanoacrylate-based ultraviolet absorbers, and provides a green multilayer polycarbonate sheet .

The ultraviolet absorber may be at least one selected from the group consisting of 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl- Benzyltriazole, 2,2'-methylenebis [6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethyl Butylphenol], 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5 - [(hexyl) oxy] -phenol, 1,3- 3 ', 3'-phenylacrylonyl] oxy} methyl} propane, edile-2', 2'- Cyano-3,3-diphenylacrylate, tetra-ethyl-2,2 '- (1,4-phenylene-dimethylidene) -bismonate, dimethyl 4-methoxybenzylidmalonate, 2- 4-methylphenol and 3- (diaryl) [1,3,5] triazin-2-yl) -5- (Alkoxy substistuted) -phenol. The present invention also provides a green multi-layer polycarbonate sheet.

The multilayer polycarbonate sheet has a scratch resistance of not less than a pencil hardness F measured according to the following method and has a weather resistance of less than 4 as measured by the following method.

[How to measure]

The multilayer sheet having a total thickness of 3 mm and a coating layer thickness of 102 占 퐉 was measured for scratch resistance according to ASTM Evaluation Method D3363 and exposed to 1,000 hours under an SAI J1960 condition using an Atlas CI4000 instrument to measure weatherability (ΔE) .

According to the present invention, a polycarbonate resin using an optimum amount of a methacrylic copolymer resin and an ultraviolet absorber is used as a coating layer and is composed of a base layer containing a polycarbonate resin, and has excellent scratch resistance and weather resistance By providing an improved multi-layer sheet, it is possible to provide a greenhouse multilayer sheet which can be used for a long period of time compared to a conventional green house, can save the cost of framing compared to a glass greenhouse, and can protect the safety of workers.

1 is a cross-sectional view schematically showing a multilayer sheet according to an example of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, when an element is referred to as "including " an element, it means that it can include other elements, not excluding other elements, unless specifically stated otherwise.

The inventors of the present invention have conducted intensive studies to develop a polycarbonate sheet having improved scratch resistance and weatherability while maintaining transparency as a plastic material capable of compensating for the disadvantages of conventional greenhouses or glass greenhouses, By using a polycarbonate resin having an ultraviolet absorber in an optimal amount as a coating layer and a multilayer sheet composed of a substrate layer containing a polycarbonate resin, and arrived at the present invention.

Accordingly, the present invention provides a coating layer comprising 43 to 89.9% by weight of a polycarbonate resin, 10 to 50% by weight of a methacrylic copolymer resin and 0.1 to 10% by weight of an ultraviolet absorber; And a base layer comprising a polycarbonate resin.

FIG. 1 schematically shows a multilayer sheet 10 according to the present invention. The cover layer 11 may be laminated on one side or both sides of a base layer 12. First, components constituting the multilayer sheet according to the present invention will be described in detail.

Polycarbonate resin

The polycarbonate (PC) resin used in the coating layer and the base layer in the present invention is an amorphous polymer, which is excellent in transparency, excellent in impact resistance, self-extinguishing property, flexibility and processability, excellent in weatherability, And excellent cold resistance can maintain performance even under severe temperature changes.

The polycarbonate resin may be prepared by a conventional method, for example, by reacting a dihydroxy phenol compound with a phosgene in the presence of a molecular weight modifier and a catalyst, or by reacting dihydroxy Can be prepared using an ester interchange reaction of a phenol compound and a precursor obtained by diphenyl carbonate.

Here, as the dihydroxyphenol compound, a bisphenol compound may be used, and bisphenol A (2,2-bis (4-hydroxyphenyl) propane) may be preferably used. At this time, the bisphenol A may be partially or wholly replaced with another kind of dihydroxy phenolic compound. (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis Bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfone, bis Bis (4-hydroxyphenyl) ether, 2,2, -bis (3,5-dibromo-4-hydroxyphenyl) propane and the like.

The polycarbonate resin may be a homopolymer of a dihydroxy phenolic compound, a copolymer of two or more dihydroxy phenolic compounds, or a mixture thereof.

In general, the polycarbonate resin may have the form of a linear polycarbonate resin, a branched polycarbonate resin, a polyester carbonate copolymer resin or the like. As the polycarbonate resin contained in the polycarbonate resin composition used in the present invention, But the linear polycarbonate resin, the branched polycarbonate resin, or the polyester carbonate copolymer resin and the like can be used. As the linear polycarbonate resin, for example, a bisphenol A-based polycarbonate resin may be used. As the branched polycarbonate resin, for example, a polyfunctional aromatic compound such as trimellitic anhydride or trimellitic acid With a dihydroxyphenol compound and a carbonate precursor can be used. As the polyester carbonate copolymer resin, for example, a bifunctional carboxylic acid can be prepared by reacting a dihydroxyphenol compound and a carbonate precursor, May be used.

In the present invention, the polycarbonate resin constituting the coating layer is contained in an amount of 43 to 89.9% by weight, preferably 65 to 84% by weight based on the total weight of the coating layer. If the content of the polycarbonate resin is less than 43% by weight, excellent mechanical properties of the polycarbonate may not be exhibited. If the content of the polycarbonate resin exceeds 89.9% by weight, improvement of scratch resistance and weatherability may not be expected.

In the present invention, the polycarbonate resin may have a weight average molecular weight of 10,000 to 200,000, preferably 15,000 to 80,000, and more preferably 20,000 to 50,000.

On the other hand, the base layer may further contain 0.1 to 10% by weight of an ultraviolet absorbent described later together with a polycarbonate resin to protect the polycarbonate resin from harmful effects due to ultraviolet rays in the atmosphere.

Methacrylic system  Copolymer resin

In the present invention, the methacrylic copolymer resin used for the coating layer is prepared for improving the scratch resistance and weatherability through the coating layer and improving the fogging property and the permeability, and preferably has a weight average molecular weight of 2,000 or more and less than 3,000, It has excellent compatibility in blending with a polycarbonate resin in an average molecular weight range, and a specimen having uniform surface condition can be obtained during specimen molding, and particularly excellent characteristics in terms of fogging property and permeability can be obtained. Further, by using a methacrylic copolymer resin having a high refractive index of 1.52 to 1.58, haze in a blended molding product with a polycarbonate resin can be maintained at a high transparency of 0.9% or less, which is equivalent to that of polycarbonate. Here, the methacrylic copolymer resin having a high refractive index is a resin modified with an aromatic or aliphatic methacrylate, and can be polymerized by conventional bulk, emulsion and suspension polymerization methods.

In the present invention, the methacrylic copolymer resin may be a copolymer of 10 to 100% by weight of aromatic or aliphatic methacrylate and 0 to 90% by weight of monofunctional unsaturated monomer. When the aromatic or aliphatic methacrylate is less than 10% by weight, the average refractive index of the polymerized methacrylic copolymer resin may be less than 1.52. The methacrylic copolymer may be represented by the following general formula (1).

[Chemical Formula 1]

(Wherein m is an integer of 0 to 10, and X is a methyl group, a phenyl group, a cyclohexyl group, a methylphenyl group, a methylethylphenyl group, a propylphenyl group, a methoxyphenyl group, a cyclohexylphenyl group, a chlorophenyl group, Or a benzylphenyl group)

The aromatic or aliphatic methacrylate includes, for example, cyclohexyl methacrylate, 2-ethylphenoxy methacrylate, 2-ethylthiophenyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2- Ethylmethacrylate, 3-phenylpropylmethacrylate, 4-phenylbutylmethacrylate, 2,2-methylphenylethylmethacrylate, 2,3-methylphenylethylmethacrylate, 2,4-methylphenylethylmethacrylate Ethyl methacrylate, 2- (4-methylphenyl) ethyl methacrylate, 2- (4-methoxyphenyl) 2- (3-chlorophenyl) ethyl methacrylate, 2- (4-chlorophenyl) ethyl methacrylate, 2- 2- (4-bromophenyl) ethyl methacrylate, 2- (3-phenylphenyl) ethyl methacrylate, 2- There may be mentioned acrylate and the like.

Examples of the monofunctional unsaturated monomer include methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl methacrylate and the like, acrylates such as methyl acrylate, ethyl Unsaturated carboxylic acids such as acrylic acid and methacrylic acid, acid anhydrides such as maleic anhydride and the like, acid anhydrides such as 2-hydroxyethyl acrylate, 2-ethylhexyl acrylate, Acrylate, methacrylamide, acrylonitrile, methacrylonitrile, allyl glycidyl ether, glycidyl methacrylate, styrene, acrylonitrile, methacrylonitrile, methacrylonitrile, Alpha methyl styrene, and the like.

In the present invention, the methacrylic copolymer resin is contained in an amount of 10 to 50% by weight, preferably 15 to 34% by weight based on the total weight of the coating layer. If the content of the methacrylic copolymer resin is less than 10% by weight, it may be difficult to expect improvement in scratch resistance. If the content of the methacrylic copolymer resin is more than 50% by weight, the weather resistance may decrease and a flow mark have.

Ultraviolet absorber

The ultraviolet absorber used in the coating layer in the present invention means a component that blocks ultraviolet energy or selectively absorbs ultraviolet energy and emits it in another form of energy that is not harmful to the polymer or inhibits the photoreaction of the polymer, And is contained in an amount of 0.1 to 10% by weight, preferably 1 to 5% by weight based on the total weight of the coating layer. The weather resistance of the multilayer polycarbonate sheet can be improved without causing deterioration of the mechanical properties and bleeding of the absorbent onto the surface of the multilayer polycarbonate sheet according to the content.

The ultraviolet absorber is not particularly limited as long as it has the above-mentioned function, but it is preferably 2- (2H-benzotriazole-2-yl) -4,6-bis (1-methyl- Benzotriazole, 2,2'-methylenebis [6- (2H-benzotriazol-2-yl) 4- (1,1,3,3-tetramethylbutyl) phenol], 2- (4,6-diphenyl-1,3,5-triazin- ] -Phenol, 1,3-bis- [2'-cyano-3 ', 3-diphenylacryronyl] oxy] -2,2-bis - {[ Phenyl acrylonyl] oxy} methyl} propane, edile 2-cyano-3,3-diphenylacrylate, tetra-ethyl-2,2 '- (1,4-phenylene-dimethylidene) Methoxybenzylidmalonate, 2-tert-butyl-6- (5-chloro-2H-benzotriazol- 3,5] triazin-2-yl) -5- (alkoxy substistuted) -phenol may be used.

The coating layer and the base layer constituting the multilayer polycarbonate according to the present invention may further contain other additives depending on the respective applications within the range not deviating from the object. As a further additive, a hindered amine light stabilizer, a releasing agent, an epoxy compound, a heat stabilizer or an antioxidant may be added in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of each coat layer or substrate layer.

In the present invention, the multilayer polycarbonate sheet may include at least one coating layer and a substrate layer, respectively. By forming a coating layer on one side or both sides of the substrate layer, the polycarbonate contained in the substrate layer by ultraviolet and infrared ray- Direct ultraviolet contact to the resin can be minimized. As a result, the yellowing of the polycarbonate resin due to the direct UV contact can be prevented, and the weather resistance of the multilayer polycarbonate sheet can be improved as well.

The thickness of the coating layer and the base layer may be determined depending on the physical properties and specific use of the multilayer polycarbonate sheet. However, the thickness of the coating layer particularly when used in a greenhouse may be 0.01 to 1 mm. In order to further improve scratch resistance and weatherability And is preferably 0.1 mm or more.

The methacrylic copolymer / polycarbonate resin composition constituting the coating layer in the present invention can be produced by a known method. For example, the polycarbonate resin and the methacrylic copolymer resin may be mixed with other additives at the same time and then melt-extruded in an extruder to produce pellets. The pellets may be used for forming a multilayer sheet described later. The melt extrusion may be carried out at a screw rotation speed of 50 to 1000 rpm for a retention time of 5 to 90 seconds, preferably at a screw rotation speed of 200 to 800 rpm for a retention time of 10 to 60 seconds. The residence time is preferably 90 seconds or less in order to prevent deterioration of the methacrylic copolymer resin and to improve productivity.

The substrate layer composed of the coating layer composed of the methacrylic copolymer / ultraviolet absorber / polycarbonate resin composition and the polycarbonate may be formed into a multilayer sheet using coextrusion. Co-extrusion refers to a method of making a multi-layer structure by using at least two extruders to add one or more layers in extrusion coating, film or sheet production. The co-extrusion process is not particularly limited, and the coating layer and the base layer may be formed by a general co-extrusion process. For example, there are a method of joining the substrate layer and the coating layer pushed out from two or more extruders at a roll, a method of pneumatic shipment using a single extrusion die using a multi-nozzle, and the like. However, in order to achieve good scratch resistance and weatherability of the coating layer during the co-extrusion process, it is important that the coating layer is formed to a thickness of 100 탆 or more as described above.

The scratch resistance of the multilayer polycarbonate sheet produced according to the present invention was measured in accordance with ASTM evaluation method D3363 on the basis of a multilayer sheet having a total thickness of 3 mm and a coating layer thickness of 102 mu m and was measured using an Atlas CI4000 instrument under SAE J1960 conditions When the weather resistance (DELTA E) is measured using a colorimeter after 1,000 hours of exposure, the scratch resistance can exhibit a pencil hardness F or more and a weather resistance of less than 4. Hereinafter, specific examples and comparative examples according to the present invention will be described.

First, the component specifications used in Examples and Comparative Examples are as follows.

The substrate layer

(A) Polycarbonate resin

A polycarbonate resin (PC-1070U, LOTTE CHEMICAL) having a melt index (300 DEG C, 1.2 kg) of 7.0 and a weight average molecular weight of 25,000 was used.

Coating layer

(A) Polycarbonate resin

A polycarbonate resin (PC-1070U, LOTTE CHEMICAL) having a melt index (300 DEG C, 1.2 kg) of 7.0 and a weight average molecular weight of 20,000 to 50,000 was used.

(B) a methacrylic copolymer resin

H-880 (refractive index: 1.54 to 1.56, weight average molecular weight: 2,500) of Mitsubishi Rayon, which is a commercially available product, was used.

(C) Ultraviolet absorber

A commercially available product, Tinuvin-1600 (2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol) from BASF was used.

Example  One

To prepare a methacrylic copolymer / ultraviolet absorber / polycarbonate resin composition as a coating layer, 88.5 parts by weight of a polycarbonate resin, 10 parts by weight of a methacrylic copolymer resin, 1.5 parts by weight of an ultraviolet absorber and 0.1 parts by weight of a commercial antioxidant And a pellet-shaped polycarbonate resin composition was produced under the extrusion conditions of an extrusion temperature of 270 to 300 ° C and a screw rotation speed of 200 rpm using a twin screw extruder (screw diameter 26 mm, L / D = 40) Respectively. Thereafter, a first extruder (screw diameter 120 mm, L / D = 40, screw rotation speed 35 rpm) and a second extruder (screw diameter 65 mm, L / D = 30 rpm) , Screw rotation speed: 25 rpm), the temperature of the die was adjusted to 230 to 280 占 폚 according to the flow of the resin and the temperature of the roll was controlled to 100 to 120 占 폚 to cooperate to produce a multilayer sheet having a total thickness of 3 mm and a coating layer thickness of 102 占 퐉 Respectively.

Example  2

A multilayer sheet was prepared in the same manner as in Example 1, except that 78.5 parts by weight of a polycarbonate resin and 20 parts by weight of a methacrylic copolymer resin were mixed at the time of preparing the coating layer in Example 1.

Example  3

A multilayer sheet was prepared in the same manner as in Example 1, except that 68.5 parts by weight of a polycarbonate resin and 30 parts by weight of a methacrylic copolymer resin were mixed in the coating layer in Example 1.

Example  4

A multilayer sheet was prepared in the same manner as in Example 1, except that 58.5 parts by weight of a polycarbonate resin and 40 parts by weight of a methacrylic copolymer resin were mixed in the coating layer in Example 1.

Example  5

A multilayer sheet was prepared in the same manner as in Example 1, except that 48.5 parts by weight of a polycarbonate resin and 50 parts by weight of a methacrylic copolymer resin were mixed at the time of preparing the coating layer in Example 1.

Comparative Example  One

A multilayer sheet was prepared in the same manner as in Example 1, except that the methacrylic copolymer resin and the ultraviolet absorber were not mixed in the preparation of the coating layer in Example 1, but 100 parts by weight of the polycarbonate resin was used.

Comparative Example  2

A multilayer sheet was prepared in the same manner as in Example 1, except that the ultraviolet absorber was not mixed at the time of preparing the coating layer in Example 1, but the ratio was 70 parts by weight of the polycarbonate resin and 30 parts by weight of the methacrylic copolymer resin .

Comparative Example  3

A multilayer sheet was prepared in the same manner as in Example 1, except that the methacrylic copolymer resin was not mixed with the polycarbonate resin in the preparation of the coating layer in Example 1, except that 98.5 parts by weight of the polycarbonate resin was used.

Test Example

The haze, the transmittance, the scratch resistance and the weather resistance of the multilayer polycarbonate sheet according to the present invention were measured according to the following method. The results are shown in Table 1 below.

[How to measure]

(1) Cloudiness

ASTM evaluation method D1003.

(2) Transmittance

ASTM evaluation method D1003.

(3) scratch resistance

It was measured according to ASTM Evaluation Method D3363.

(4) Weatherability

The AtE CI4000 instrument was used to measure ΔE using a colorimeter after 1,000 hours exposure under SAE J1960 conditions.

Referring to Table 1, a coating layer using a methacrylic copolymer / ultraviolet absorber / polycarbonate resin composition having a component composition range according to the present invention and a multilayer sheet formed of a base layer using a polycarbonate resin (Examples 1 to 5 ) Was improved in weather resistance and scratch resistance as compared with the multilayer sheet (Comparative Example 1) formed of a coating layer composed of pure polycarbonate not using an ultraviolet absorber and a methacrylic copolymer.

Compared with the multilayer sheet (Comparative Example 3) formed with the coating layer without the methacrylic copolymer, the weather resistance performance was improved as compared with the multilayer sheet formed with the coating layer without using the ultraviolet absorber (Comparative Example 2) Is improved.

The preferred embodiments of the present invention have been described in detail above. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning, range, and equivalence of the claims are included in the scope of the present invention Should be interpreted.

10: multilayer sheet 11: coating layer
12: substrate layer

Claims (6)

A covering layer comprising 43 to 89.9% by weight of a polycarbonate resin, 10 to 50% by weight of a methacrylic copolymer resin and 0.1 to 10% by weight of an ultraviolet absorber; And
A base layer comprising a polycarbonate resin;
≪ / RTI >
The methacrylic copolymer resin is a copolymer of 10 to 100% by weight of an aliphatic or aromatic methacrylate represented by the following formula (1) and 0 to 90% by weight of a monofunctional unsaturated monomer, and has a weight average molecular weight of less than 2,000 and less than 3,000, Layer polycarbonate sheet having a refractive index of 1.52 to 1.58.
[Chemical Formula 1]

(Wherein m is an integer of 0 to 10, and X is a methyl group, a phenyl group, a cyclohexyl group, a methylphenyl group, a methylethylphenyl group, a propylphenyl group, a methoxyphenyl group, a cyclohexylphenyl group, a chlorophenyl group, Or a benzylphenyl group) The method according to claim 1,
Wherein the coating layer and the polycarbonate resin of the base layer have a weight average molecular weight of 10,000 to 200,000. delete The method according to claim 1,
Wherein the ultraviolet absorber is at least one selected from the group consisting of benzotriazole-based, benzophenone-based, benzotriazine-based, malonate-based and cyanoacrylate-based ultraviolet absorbers. 5. The method of claim 4,
The ultraviolet absorber may be selected from the group consisting of 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl- Benzyltriazole, 2,2'-methylenebis [6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) Phenol], 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5 - [(hexyl) oxy] -phenol, 2-cyano-3 ', 3'-phenyl acrylonyl] oxy} methyl} propane, ethyl 2-cyano 3,3-diphenylacrylate, tetra-ethyl-2,2 '- (1,4-phenylene-dimethylidene) -bismarnonate, dimethyl 4-methoxybenzylidmalonate, Yl) -4-methylphenol and 3- (diaryl) [1,3,5] triazin-2-yl) -5- Alkoxysubstlisted) -phenol. ≪ / RTI > The green sheet for multilayer polycarbonate sheet for greenhouse according to claim 1, The method according to claim 1,
Wherein the multilayer polycarbonate sheet has a scratch resistance of not less than pencil hardness F measured according to the following method and has a weather resistance of less than 4 as measured by the following method.
[How to measure]
The multilayer sheet having a total thickness of 3 mm and a coating layer thickness of 102 占 퐉 was measured for scratch resistance according to ASTM Evaluation Method D3363 and exposed to 1,000 hours under an SAI J1960 condition using an Atlas CI4000 instrument to measure weatherability (ΔE) .

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