KR20140084462A - High weatherable acrylic film having improved surface property and stress whitening resistibility - Google Patents

Abstract

The present invention relates to a stress-whitening resistant film which comprises a first layer formed by dispersing 50-60 parts by weight of a graft copolymer into 100 parts by weight of a first acryl-based resin matrix; and a second layer formed by 65-400 parts by weight of a graft copolymer into 100 parts by weight of a second acryl-based resin matrix.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a high weather-resistant acrylic film excellent in stress resistance, whitening resistance and surface properties,

The present invention is directed to a highly weatherable acrylic film.

Acrylic film is widely used in the field of construction materials due to its excellent weatherability. For example, JP 2007-182585 A discloses a laminate film excellent in weatherability and flexibility by using a block copolymer. In recent years, a laminate film having excellent weather resistance and flexibility has been developed. In order to improve the processing characteristics, especially the softness characteristics, a method of adding a rubber reinforcing agent is developed.

However, when the content of the impact modifier in the film is increased, there arises a problem that the gel is formed on the surface of the film although the soft characteristic is high, and the gloss of the film is lowered. Further, when a hard layer is introduced on the surface in order to improve the appearance characteristics, there is a problem that the surface of the film is cracked or peeled off depending on the processing conditions.

Accordingly, the inventors of the present invention have been studying an acrylic film having excellent stress whitening resistance, weather resistance, and surface characteristics, and have found that an acrylic film containing a specific range of impact reinforcing material having a specific structure as a rubber is formed into a multilayer structure, It is possible to produce an acrylic film excellent in both surface characteristics, stress-resistance whitening property, and weather resistance, thereby completing the present invention.

An object of the present invention is to provide a high weather-resistant acrylic film excellent in stress relaxation resistance, weather resistance and surface properties.

According to an aspect of the present invention,

A first layer formed by dispersing 5 to 60 parts by weight of a graft copolymer in 100 parts by weight of a first acrylic resin matrix;

And a second layer formed by dispersing 65 to 400 parts by weight of a graft copolymer in 100 parts by weight of a second acrylic resin matrix,

The first acrylic resin and the second acrylic resin provide a stress-relieving film having a resin composition which is not the same.

The acrylic film of the present invention is excellent in stress relaxation resistance, surface characteristics and weather resistance.

Figure 1 schematically shows the graft copolymer of the present invention.
2 is an embodiment of the acrylic film of the present invention.
Fig. 3 shows the folding of the acrylic film of the present invention for testing stress-resistance whitening resistance.

According to the present invention,

A first layer 10 formed by dispersing 5 to 60 parts by weight of the graft copolymer 100 in 100 parts by weight of the first acrylic resin matrix 200;

And a second layer (20) formed by dispersing 65 to 400 parts by weight of the graft copolymer (100) in 100 parts by weight of the second acrylic resin matrix (300)

The first acrylic resin and the second acrylic resin are for a stress-relieving film having a resin composition which is not the same.

Further, according to the present invention,

The present invention relates to a building material including the stress-relieving film of the present invention.

Further, according to the present invention,

The present invention relates to a window including an intrinsic stress-free film of the present invention.

Further, according to the present invention,

Preparing a graft copolymer (100) having a core-shell structure;

Dispersing 5 to 60 parts by weight of the graft copolymer in 100 parts by weight of the first acrylic resin matrix 200 to form a first composition and pelletizing the first composition;

Dispersing 65 to 400 parts by weight of the graft copolymer in 100 parts by weight of the second acrylic resin matrix 300 to form a second composition and pelletizing the second composition;

And pneumatically discharging the first composition and the second composition in the form of pellets.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, with reference to the accompanying drawings, a high-weatherability acrylic film having excellent stress relaxation resistance and surface characteristics according to the present invention will be described in detail.

The graft copolymer (100)

The structure of the graft copolymer (100)

The graft copolymer 100 of the present invention has a core-shell structure and the shell 140 comprises a core 110 and a grafted first shell layer 120, and a first shell layer 120 and a grafted And has a structure of the second shell layer 130. Figure 1 schematically shows the structure of the graft copolymer (100) of the present invention, which shows the arrangement of the core-first shell layer-second shell layer, and in fact they are grafted to one another.

The graft copolymer 100 has a particle size of 100 to 200 nm, a size of the core 110 is 20 to 60 nm, and a thickness of the shell 140 is 40 to 70 nm. Here, the thickness of the shell 140 means (average diameter of graft copolymer - average diameter of core) / 2.

The graft copolymer (100) of the present invention acts as an impact modifier. If the graft copolymer (100) has a particle size of less than 100 nm, it fails to properly absorb external impacts applied thereto, , The physical properties of the film become unsatisfactory. When the size of the graft copolymer (100) exceeds 200 nm, a gap is opened between the acrylic resin matrix (200, 300) and the graft copolymer (100) It is prone to bleaching phenomenon.

On the other hand, when the size of the core 110 is less than 20 nm, it is not easy to form particles by a general emulsion polymerization method, and the efficiency of the graft polymerization is deteriorated so that the physical properties of the impact modifier are not uniform. Further, when the size of the core 110 exceeds 60 nm, it is not easy to control the overall size of the graft copolymer (100) particles to less than 200 nm by graft polymerization, and the haze value of the film increases There is a limit to obtaining highly transparent products.

If the thickness of the shell 140 is less than 40 nm, the uniformity of the shell 140 is lowered. In such a case, the core 110 may be exposed to the outside, which may adversely affect the physical properties and appearance quality. If the thickness of the shell 140 is increased to 70 nm or more, the polymerization time for forming the shell is long, and the effect of improving the impact may be relatively small.

 The graft copolymer (100) has a structure in which a shell (140) is formed by grafting a copolymer containing alkyl methacrylic acid as a main component to a copolymer constituting the core (110). Preferably, the graft copolymer (100) is obtained by grafting a copolymer mainly composed of alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group on the copolymer constituting the core (110) Form.

The core 110,

The core 110 is formed by cross-linking a copolymer containing an alkyl acrylate as a main component, and a glass transition temperature of the core is -60 to -30 ° C. When the glass transition temperature of the core 110 is higher than -30 占 폚, the impact absorbing ability is lowered and the performance as an impact modifier is deteriorated.

Preferably, the core 110 is composed of 9 to 13 parts by weight of alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group and 0.5 to 1.5 parts by weight of allyl methacrylic acid per 100 parts by weight of alkyl acrylate having 4 to 8 carbon atoms in the alkyl group Weight parts are formed by copolymerization. The alkyl acrylate having 4 to 8 carbon atoms in the alkyl group may be butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate and the like, preferably butyl acrylate. The alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group may be methyl methacrylate, ethyl methacrylate, propyl methacrylate and the like, preferably methyl methacrylate. More preferably, the core is formed by copolymerizing 9 to 13 parts by weight of methyl methacrylate (MMA) and 0.5 to 1.5 parts by weight of allyl methacrylate (AMA) with respect to 100 parts by weight of butyl acrylate (BA) And is formed by crosslinking.

The shell (140)

The shell 140 is formed of a first shell layer 120 and a second shell layer 130.

The first shell layer 120 includes 100 parts by weight of alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group of the copolymer constituting the core 110, 8 to 15 parts by weight of alkyl acrylate having 4 to 8 carbon atoms in the alkyl group, And 4 to 7 parts by weight of aromatic aromatic hydrocarbons are grafted while being copolymerized. The alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group may be methyl methacrylate, ethyl methacrylate, propyl methacrylate and the like, preferably methyl methacrylate. The alkyl acrylate having 4 to 8 carbon atoms in the alkyl group may be butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate and the like, preferably butyl acrylate. The vinyl aromatic hydrocarbon is for adjusting the reactivity and the refractive index, and may be styrene, divinylbenzene, alpha methyl styrene, and the like, preferably styrene. More preferably, the first shell layer is composed of a copolymer of 100 parts by weight of methyl methacrylate and 8 to 15 parts by weight of butyl acrylate and 5 parts by weight of styrene.

The second shell layer 130 may include 100 parts by weight of alkyl methacrylate having 1 to 3 carbon atoms in the copolymer of the first shell layer 120 and 8 to 15 parts by weight of alkyl acrylate having 4 to 8 carbon atoms in the alkyl group And are grafted and formed. The alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group may be methyl methacrylate, ethyl methacrylate, propyl methacrylate and the like, preferably methyl methacrylate. The alkyl acrylate having 4 to 8 carbon atoms in the alkyl group may be butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate and the like, preferably butyl acrylate. More preferably, the second shell layer comprises a copolymer obtained by copolymerizing 100 parts by weight of methyl methacrylate and 8 to 15 parts by weight of butyl acrylate. Due to compatibility with the acrylic resin matrices (100, 200), the monomer forming the copolymer constituting the second shell layer does not include aromatic hydrocarbons such as styrene.

Process for producing graft copolymer (100)

The graft copolymer (100) of the present invention can be produced by a conventional emulsion polymerization method. For example, the graft copolymer (100) of the present invention can be produced by conventional methods such as US 4513118, US5270397, and US5063259 or by slightly modifying the conventional method, and the method of producing the graft copolymer (100) Is not particularly limited. For example, the graft copolymer 100 may be prepared by preparing a copolymer constituting the core 110, crosslinking the copolymer to form a core 110, and forming a copolymer comprising the first shell layer 120 And the second shell layer 130 is formed by grafting while forming a first shell layer 120 and forming a copolymer constituting the second shell layer 130. In this case, It is obvious that the specific and detailed process of the step can be appropriately selected and carried out by a person skilled in the art.

The first acrylic resin matrix 200

The first acrylic resin matrix 200 of the present invention has a glass transition temperature of 80 to 110 DEG C and a molecular weight of 80,000 to 150,000. If the glass transition temperature of the first acrylic resin matrix 200 is less than 80 占 폚 or the molecular weight is less than 80,000, the first acrylic resin matrix 200 becomes too soft and the surface scratch characteristics of the first layer deteriorate, It is not suitable to use one layer as the surface layer of the film. If the glass transition temperature of the first acrylic resin matrix 200 exceeds 110 ° C or the molecular weight exceeds 150,000, fine cracking may occur on the surface of the film when the film is folded, and unmelted gel may be formed on the film have.

Preferably, the first acrylic resin matrix 200 comprises 100 parts by weight of alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group and 4 to 18 parts by weight of alkyl acrylate having 4 to 8 carbon atoms in the alkyl group by conventional suspension polymerization And a copolymer formed by copolymerization. The alkyl methacrylic acid in which the alkyl group has 1 to 3 carbon atoms may be methyl methacrylate, ethyl methacrylate, propyl methacrylate and the like, preferably methyl methacrylate. The alkyl acrylate having 4 to 8 carbon atoms in the alkyl group may be butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate and the like, preferably butyl acrylate.

The second acrylic-based resin matrix 300,

The second acrylic resin matrix 300 of the present invention has a glass transition temperature of 70 to 100 DEG C and a molecular weight of 50,000 to 120,000. When the second acrylic resin matrix 300 has a glass transition temperature of less than 70 占 폚 or a molecular weight of less than 50,000, the stretching property of the film is deteriorated. When the glass transition temperature of the second acrylic resin matrix 300 exceeds 100 ° C or the molecular weight exceeds 120,000, the soft characteristics of the film become insufficient.

Preferably, the second acrylic resin matrix 300 comprises 100 parts by weight of alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group and 4 to 18 parts by weight of alkyl acrylate having 4 to 8 carbon atoms in the alkyl group by conventional suspension polymerization And a copolymer formed by copolymerization. The alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group may be methyl methacrylate, ethyl methacrylate, propyl methacrylate and the like, preferably methyl methacrylate. The alkyl acrylate having 4 to 8 carbon atoms in the alkyl group may be butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate and the like, preferably butyl acrylate.

The first acrylic resin constituting the first acrylic resin matrix 200 and the second acrylic resin constituting the second acrylic resin matrix 300 do not have the same resin composition. That is, although the first acrylic resin and the second acrylic resin are all copolymers and the monomers constituting the both copolymers may be common, the ratio between the monomers, the copolymerization time, and the copolymerization temperature are different. Molecular weight or glass transition temperature. Preferably, the glass transition temperature of the first acrylic resin is higher than the glass transition temperature of the second acrylic resin, and the molecular weight of the first acrylic resin is larger than the molecular weight of the second acrylic resin. By varying the components of the resin matrix of the first layer 10 and the second layer 20 in this way, it is possible to compensate for the disadvantages of the single-layer film, thereby providing a film having excellent surface characteristics and simultaneously enhanced mechanical strength.

When the first acrylic resin matrix and the second acrylic resin matrix are prepared, additives such as antioxidants and UV stabilizers besides the monomers forming the copolymer may be added. The antioxidant may be Irganox 1076, Irganox 1010 or the like, and the UV stabilizer may be Tiuvin 234, Tinuvin 360 or the like, but is not limited thereto.

The first layer (10)

The first layer (10) of the present invention is formed by dispersing the graft copolymer (100) in the first acrylic resin matrix (200). Preferably, the first layer of the present invention has a structure in which the graft copolymer 100 is dispersed in the first acrylic resin matrix 200, wherein the copolymer of the shell 140 of the graft copolymer 100 is a It may be mixed with the first acrylic resin.

The first layer 10 is preferably 5 to 60 parts by weight based on 100 parts by weight of the first acrylic resin matrix 200 and the graft copolymer 100. When the content of the graft copolymer (100) is less than 5 parts by weight, cracks tend to occur on the surface of the produced film. When the content of the graft copolymer (100) exceeds 60 parts by weight, The surface characteristics such as surface roughness are deteriorated.

Second layer

The second layer (20) of the present invention is formed by dispersing the graft copolymer (100) in the second acrylic resin matrix (300). Preferably, the second layer of the present invention has a structure in which the graft copolymer (100) is dispersed in the second acrylic resin matrix (300), wherein the copolymer of the shell (140) of the graft copolymer (100) It may be mixed with the second acrylic resin.

The second layer 20 is preferably 65 to 400 parts by weight of the graft copolymer 100 based on 100 parts by weight of the second acrylic resin matrix 300. When the content of the graft copolymer (100) is less than 65 parts by weight, the softening performance is not sufficient and the stretching property of the film becomes insufficient. When the content of the graft copolymer (100) exceeds 400 parts by weight, The gel content is excessively increased and the workability is deteriorated when the film is extruded.

Stress-relief film

Structure of film

The film of the present invention comprises the first layer 10 and the second layer 20, which are laminated in direct contact (FIG. 2). When the film of the present invention includes only one of the first layer 10 and the second layer 20, the first layer 10 having excellent appearance characteristics is exposed to the outside, and the second layer 10 having a higher elongation It is preferred that the layer 20 be located internally or in contact with the substrate.

The thickness of the second layer 20 is preferably greater than or equal to the thickness of the first layer 10. More preferably, the thickness of the first layer 10 and the thickness of the second layer 20 have a ratio of 1: 1 to 9. The film of the present invention can be used as a surface layer or a protective layer of a door exposed to a window or outdoors. When the thickness of the film is less than 40 탆, the ultraviolet blocking effect becomes insignificant. When the thickness exceeds 150 탆, And it is inefficient. Also, when the thicknesses of the first layer 10 and the second layer 20 are 1: 1 to 9, the scratch characteristics of the film surface are high and the softness characteristics of the film are effectively exhibited.

The film of the present invention may further comprise a first layer 10 so as to be the structure of the first layer 10 / the second layer 20 / the first layer 10. In this case, each of the first layers 10 may independently have a thickness of 10 to 30% of the total film thickness, and the second layer 20 may have a thickness of 40 to 80%.

Further, the film of the present invention may further include other layers such as the first layer and the second layer outer base layer, the decorative layer, the UV layer, and the protective layer.

Method of manufacturing film

The method for producing a film of the present invention comprises:

Preparing a graft copolymer (100) having a core-shell structure;

Dispersing 5 to 60 parts by weight of the graft copolymer in 100 parts by weight of the first acrylic resin matrix 200 to form a first composition and pelletizing the first composition;

Dispersing 65 to 400 parts by weight of the graft copolymer in 100 parts by weight of the second acrylic resin matrix 300 to form a second composition and pelletizing the second composition;

Pneumatic delivery of the first and second compositions in pellet form. At this time, the co-extrusion process is a general film extrusion process and is not particularly limited.

It is preferable that the film of the present invention be pneumatically delivered rather than preparing and bonding the first layer 10 and the second layer 20 respectively. The coextrusion method is simple and advantageous in terms of cost, This is because the first layer 10 and the second layer 20 are not easily separated. However, this is merely that the film of the present invention is produced by a co-extrusion method, and does not mean that it is outside the scope of the present invention to manufacture the film by a method other than the co-extrusion method.

Characteristics of film

The film of the present invention has an elongation of 85 to 115% and an elongation of the second layer 20 is greater than that of the first layer 10.

The film of the present invention has stress-strain whitening resistance. Specifically, the film of the present invention does not show a whitening phenomenon in the folded portion A of the first layer 10 when the film is folded at 90 degrees such that the second layer 20 is inward as shown in FIG.

Further, the film of the present invention does not show a gel on its surface when observed with naked eyes.

Use of film

The present invention provides building materials, furniture and the like comprising the film of the present invention. The building material is a general building material and is not particularly limited. For example, the building material may be a window, a window frame, a column, an interior finishing material, but is not limited thereto. The furniture may be, but is not limited to, household furniture, office furniture, prefabricated furniture, and the like.

Hereinafter, the present invention will be described in detail. The copolymer of the following graft copolymer and acrylic resin matrix was polymerized by a conventional method.

≪ Preparation of graft copolymer >

IM-1

0.25 parts by weight of dioctyl sodium sulfosuccinate, 0.075 parts by weight of sodium formaldehyde sulfoxylate, 0.001 part by weight of EDTA2Na and 0.00025 parts by weight of iron sulfate were added to a reactor And the temperature was raised to 60 占 폚. 15 parts by weight of Solution A was then added over 2 hours and further polymerized for 30 minutes to prepare a core having a core particle size of 50 nm and a Tg of -30 캜 or lower. Then, 10 parts by weight of Solution B was added over 90 minutes and further polymerized for 30 minutes. Then, 25 parts by weight of Solution C was added over 3 hours and further polymerized for 1 hour. The particle size of the final polymerized product was 150 nm, and 0.01 part by weight of calcium chloride was added thereto, followed by agglomeration at 70 ° C. The obtained powder was washed with distilled water, dehydrated and dried.

The solution A was copolymerized using butyl acrylate, methyl methacrylate (MMA), allyl methacrylate (AMA) and cumene hydroperoxide (CHP) in a weight ratio of 90: 10: 1: 0.05 . Solution B was prepared by copolymerizing butyl acrylate, MMA, styrene, tert-docdecylmercaptan, and CHP in a weight ratio of 10: 85: 5: 0.5: 0.5. Solution C was prepared by copolymerizing butyl acrylate, MMA, tert-docdecylmercaptan, and CHP in a weight ratio of 10: 90: 0.5: 0.5.

IM-2

Except that 25 parts by weight of Solution A, 10 parts by weight of Solution B and 20 parts by weight of Solution C were used for 100 parts by weight of ion-exchanged water to prepare graft copolymers. The particle size of the core of the IM-2 graft copolymer was 60 nm, and the particle size of the final polymer was 110 nm.

IM-3

In general, commercially available acrylic impact modifiers were purchased and used as IM-3. The commercially available acrylic impact modifier has a particle size of more than 200 nm and less than 300 nm.

<Preparation of Acrylic Resin Matrix>

PM-1

MMA, butyl acrylate, n-octylmercaptan and AIBN were mixed in a weight ratio of 90: 10: 0.2: 0.1 to prepare an acrylic mixture. 250 parts by weight of ion-exchanged water and 2 parts by weight of a polymerization dispersant were added to 100 parts by weight of the mixture, and the mixture was polymerized at 70 DEG C for 3 hours to remove residual monomers and then dried to prepare acrylic polymer in the form of beads. The acrylic polymer had a molecular weight of 120,000 and a glass transition temperature of 87 ° C.

PM-2

Acrylic polymer was prepared by polymerizing in the same manner as PM-1, except that the acrylic mixture was prepared by mixing MMA, butyl acrylate, n-octylmercaptan and AIBN in a weight ratio of 85: 15: 0.15: 0.1. The molecular weight of the acrylic polymer was 100,000, and the glass transition temperature was 83 ° C.

&Lt; Production of film &

The composition of the first layer and the composition of the second layer were prepared with the compositions shown in Table 1 below. Irganox 1010 and Tinuvin 234 were added to each composition in addition to the acrylic resin matrix and the graft copolymer. The total weight of the acrylic resin matrix and the graft copolymer was mixed in a weight ratio of Irganox 1010: Tinuvin of 100: 0.3: 2.0. The first layer composition and the second side composition were made into pellets. Then, the film was co-extruded at 240 캜 in a general film co-extrusion process using a twin-screw extruder to produce a film.

In the following Table 1, the compositions of the first layer and the second layer are expressed as parts by weight of the graft copolymer relative to 100 parts by weight of the acrylic resin matrix (for example, in the case of Example 1, the first layer is PM-1 100 And 40 parts by weight of IM-1 with respect to 100 parts by weight of PM-2, and 150 parts by weight of IM-1 with respect to 100 parts by weight of PM-2. Or IM-1 of the second layer was used in an amount of 150 parts by weight with respect to 100 parts by weight of PM-1).

&Lt; Evaluation of physical properties &

The physical properties of the films prepared in Examples 1 to 6 and Comparative Examples 1 to 8 were measured. At this time, the thicknesses of the film and each layer were analyzed using a scanning electron microscope (SEM). The elongation was measured at room temperature using a Zwick / Roell UTM. At this time, the specimen was measured to have a width of 10 mm and a tensile speed of 50 mm / min. As shown in Fig. 3, when the film is folded at 90 degrees so that the second layer is inwardly folded as shown in Fig. 3, when the whitening phenomenon occurs in the folded portion (A) of the first layer, ○ was marked. When the gel was observed on the surface of the film by visual observation, it was indicated by Χ, and when the gel was not observed, it was indicated by ◯. Gloss was measured at 60 degrees using a BYK Gardner Gloss Meter.

As a result, Examples 1 to 6 exhibited excellent elongation, stress relaxation resistance and gloss at 60 degrees, and no gel was observed on the surface of the film. On the other hand, in Comparative Example 1, the elongation was too low, and in Comparative Example 2 and Comparative Example 7, a gel was observed on the surface of the film. In addition, the gloss of Comparative Example 4 was too low because the content of the graft copolymer was too high to form irregularities on the surface of the film. On the other hand, in Comparative Example 8, stress whitening occurred (Table 2).

10: First layer
20: Second layer
100: graft copolymer
110: Core
120: first shell layer
130: second shell layer
140: Shell
200: First acrylic resin matrix
300: Second acrylic resin matrix

Claims (21)

A first layer formed by dispersing 5 to 60 parts by weight of a graft copolymer in 100 parts by weight of a first acrylic resin matrix;
And a second layer formed by dispersing 65 to 400 parts by weight of a graft copolymer in 100 parts by weight of a second acrylic resin matrix,
Wherein the first acrylic resin and the second acrylic resin have the same resin composition.
The method according to claim 1,
Wherein the first layer and the second layer are laminated in direct contact.
The method according to claim 1,
The graft copolymer is a core-shell structure having a particle size of 100 to 200 nm,
Wherein the core is formed by cross-linking a copolymer containing an alkyl acrylate as a main component,
Wherein the core has a glass transition temperature of from -60 to -30 占 폚.
The method according to claim 1,
The graft copolymer has a core-shell structure,
The core is formed by copolymerizing 9 to 13 parts by weight of alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group and 0.5 to 1.5 parts by weight of allyl methacrylic acid per 100 parts by weight of alkyl acrylate having 4 to 8 carbon atoms in the alkyl group Lt; / RTI &gt;
The method according to claim 1,
The graft copolymer has a core-shell structure,
Wherein a copolymer mainly composed of alkyl methacrylic acid having 1 to 3 carbon atoms of an alkyl group is grafted on the copolymer constituting the core to form a shell.
6. The method of claim 5,
The shell is formed by copolymerizing 100 parts by weight of alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group, 8 to 15 parts by weight of alkyl acrylate having 4 to 8 carbon atoms in the alkyl group and 4 to 7 parts by weight of aromatic hydrocarbon in the copolymer constituting the core A first shell layer that is grafted; And
100 parts by weight of alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group and 8 to 15 parts by weight of alkyl acrylate having 4 to 8 carbon atoms in the alkyl group are copolymerized and grafted to the copolymer of the first shell layer Lt; / RTI &gt;
The method according to claim 6,
The graft copolymer has a core-shell structure,
Wherein the first shell layer is 50-80 parts by weight and the second shell layer is 140-200 parts by weight based on 100 parts by weight of the core.
The method according to claim 1,
The graft copolymer has a core-shell structure
Characterized in that the size of the core is 20-60 nm.
The method according to claim 1,
The graft copolymer has a core-shell structure
Wherein the thickness of the shell is 40-70 nm.
The method according to claim 1,
Wherein the first acrylic resin matrix comprises a first acrylic resin having a glass transition temperature of 80 to 110 DEG C and a molecular weight of 80,000 to 150,000.
The method according to claim 1,
Wherein the first acrylic resin matrix comprises a copolymer formed by copolymerizing 100 parts by weight of alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group and 4 to 18 parts by weight of alkyl acrylate having 4 to 8 carbon atoms in the alkyl group .
The method according to claim 1,
Wherein the second acrylic resin matrix comprises a second acrylic resin having a glass transition temperature of 70 to 100 DEG C and a molecular weight of 50,000 to 120,000.
The method according to claim 1,
Wherein the second acrylic resin matrix comprises a copolymer formed by copolymerizing 100 parts by weight of alkyl methacrylic acid having 1 to 3 carbon atoms in the alkyl group and 4 to 18 parts by weight of alkyl acrylate having 4 to 8 carbon atoms in the alkyl group .
The method according to claim 1,
Wherein the thickness of the second layer is greater than or equal to the thickness of the first layer.
The method according to claim 1,
The thickness of the first layer and the thickness of the second layer have a ratio of 1: 1 to 9,
And an elongation of 85 to 115%.
The method according to claim 1,
Wherein when the film is folded at 90 degrees such that the second layer is inward, the folded portion of the first layer is not whitened.
The method according to claim 1,
Wherein the film has a thickness of 40 to 150 占 퐉.
The method according to claim 1,
Wherein the first layer is further comprised of a first layer / second layer / first layer structure.
A building material comprising the film of any one of claims 1 to 18.
18. A window comprising a film of any one of claims 1 to 18.
Preparing a graft copolymer of core-shell structure;
Dispersing 5 to 60 parts by weight of the graft copolymer in 100 parts by weight of the first acrylic resin matrix to form a first composition and pelletizing the first composition;
Dispersing 65 to 400 parts by weight of the graft copolymer in 100 parts by weight of the second acrylic resin matrix to form a second composition and pelletizing the second composition;
Pelletizing the first composition and the second composition in the pellet form.

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