Resin blend

Abstract

Provided are a resin blend, a copolymer, a pellet, a method of manufacturing a resin molded article using the same, and a resin molded article. The exemplary resin blend may provide a protective film for a polarizing plate having an excellent adhesive strength to a polarizer. In addition, when the resin blend is used, additional primer coating on the protective film for a polarizing plate may be omitted, and an excellent adhesive strength to the polarizer may be exhibited, thereby reducing production time and cost and increasing productivity.

Claims

1. A resin blend, comprising: a first resin; and a second resin of an acryl polymer having a difference in a surface energy, melt viscosity or solubility parameter from the first resin, wherein the first resin is a polymer of a first monomer blend consisting of 85 to 98 parts by weight of an alkyl(meth)acrylate having an alkyl group having 1 to 14 carbon atoms; 1 to 5 parts by weight of the monomer of Formula 1; and 3 to 10 parts by weight of the monomer of Formula 2, based on 100 parts by weight of the first monomer blend, wherein the second resin is a polymer of a second monomer blend consisting of 70 to 95 parts by weight of an alkyl(meth)acrylate having an alkyl group having 1 to 14 carbon atoms; and 5 to 30 parts by weight of the monomer of Formula 1, wherein the monomer of Formula 1 is a styrene substituted by at least one substituent, based on 100 parts by weight of the second monomer blend, wherein the second resin is hydrophobic compared to the first resin, wherein the second resin has a difference in melt viscosity form the first resin of 0.1 to 3000 pa*s at a shear rate of 100 to 1000 s.sup.1 and a processing temperature of the resin blend, wherein the second resin is included at 0.1 to 20 parts by weight with respect to 100 parts by weight of the first resin, wherein the second resin has a difference in surface energy of 0.1 to 35 mN/m at 25 C. from the first resin, wherein the second resin has a difference in melt viscosity of 0.1 to 3,000 Pa.Math.s from the first resin at a shear rate of 100 to 1,000 s.sup.1 and a processing temperature of the resin blend, wherein the second resin has a difference in solubility parameter from the solubility parameter from the first resin of 0.001 to 10.0 (J/cm.sup.3).sup.1/2 at 25 C., and wherein the second resin has a polydispersity index of 1 to 2.5 and a weight average molecular weight of 5,000 to 200,000: ##STR00005## where R.sub.1 is hydrogen or an alkyl group having 1 to 4 carbon atoms, Ar is phenyl, and R.sub.2 is hydrogen or XR.sub.6 in which X is O or OC(O), and R.sub.6 is an alkyl group having 1 to 4 carbon atoms, wherein in the second resin the styrene substituted by at least one substituent is the monomer of Formula 1 in which R.sub.2 is XR.sub.6, ##STR00006## where Y is oxygen or NR.sub.10, and R.sub.10 is hydrogen, an alkyl group having 1 to 12 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms.

2. The resin blend according to claim 1, wherein, in the first resin, the monomer of Formula 1 is styrene or -methyl styrene, and the monomer of Formula 2 is cyclohexyl maleimide or maleic acid anhydride.

3. The resin blend according to claim 1, wherein R.sub.1 is hydrogen or an alkyl-group having 1 to 4 carbon atoms, Ar is phenyl, and R.sub.2 is hydrogen or XR.sub.6 in which X is O or OC(O), and R.sub.6 is a methyl group or an ethyl group.

4. The resin blend according to claim 1, wherein, in the second resin, the monomer of Formula 1 is an unsubstituted styrene and a styrene substituted by at least one substituent selected from the group consisting of methyl, methoxy, ethoxy and acetoxy.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is an SEM image of a layer-separated cross-section of a resin molded article manufactured in Example 4;

(2) FIG. 2 is an SEM image of a cross-section of a resin molded article manufactured in Comparative Example 1; and

(3) FIG. 3 is an exemplary polarizing plate of the present application.

MODE FOR INVENTION

(4) Hereinafter, the present application will be described in detail with reference to Examples and Comparative Examples, but the range of the resin blend is not limited to the following Examples.

Preparation Example

Preparation of Second Resin

Preparation Example 1

(5) 1674 g of methylethylketone as a solvent, 810 g of methylmethacrylate (MMA) and 90 g of styrene as monomers, and 1.17 g of n-dodecyl mercaptane (n-DDM) as a chain transfer agent were put into a reactor, after 1.8 g of azobisisobutyronitrile (AIBN) as an initiator was input in a nitrogen atmosphere, the resulting blend was stirred at 400 rpm. After polymerization was performed at a reaction temperature of 70 C. for 18 hours, a resulting product was precipitated in n-hexane, washed and dehydrated three times or more, and dried in an oven at 80 C.

Preparation Example 2

(6) A second resin was prepared by the same method as described in Preparation Example 1, except that 675 g of methylmethacrylate and 225 g of styrene were used as monomers.

Preparation Example 3

(7) A second resin was prepared by the same method as described in Preparation Example 1, except that 675 g of methylmethacrylate and 225 g of acetoxystyrene were used as monomers.

Preparation Example 4

(8) A second resin was prepared by the same method as described in Preparation Example 1, except that 675 g of methylmethacrylate, 180 g of styrene, and 45 g of acetoxystyrene were used as monomers.

Preparation Example 5

(9) A second resin was prepared by the same method as described in Preparation Example 1, except that 675 g of methylmethacrylate and 225 g of methoxystyrene were used as monomers.

Preparation Example 6

(10) A second resin was prepared by the same method as described in Preparation Example 1, except that 675 g of methylmethacrylate, 180 g of styrene, and 45 g of methoxystyrene were used as monomers.

Preparation Example 7

(11) A second resin was prepared by the same method as described in Preparation Example 1, except that 900 g of methylmethacrylate was used as a monomer.

Preparation Example 8

(12) A second resin was prepared by the same method as described in Preparation Example 1, except that 450 g of methylmethacrylate and 450 g of styrene were used as monomers.

Preparation Example 9

(13) A second resin was prepared by the same method as described in Preparation Example 1, except that 450 g of methylmethacrylate and 450 g of acetoxystyrene were used as monomers.

Preparation Example 10

(14) A second resin was prepared by the same method as described in Preparation Example 1, except that 450 g of methylmethacrylate and 450 g of methoxystyrene were used as monomers.

Example 1

(15) A pellet was obtained by mixing 90 parts by weight of a first resin (a thermoplastic resin composed of 91 parts by weight of methylmethacrylate, 6 parts by weight of cyclohexylmaleimide and 3 parts by weight of -methylstyrene) and 10 parts by weight of the second resin prepared in Preparation Example 1, and extruding the resulting blend using a twin screw extruder (Leistritz) at 250 C. In addition, the pellet was extruded into an extrusion film having a thickness of 180 to 210 m at 250 C. using an extruder (Hankook EM Ltd) having a T-die gap of 1 t. The extrusion film was extended by biaxial extension in MD and TD directions at 135 C., thereby manufacturing an extension film having a thickness of approximately 50 m.

(16) The extension film including the second resin and a polarizer were laminated using an adhesive, thereby manufacturing a stack structure having a structure of the extension film including an extension film including a second resin/adhesive/PVA/adhesive/an extension film including a second resin as shown in FIG. 3. The stack structure was exposed to UV rays to cure the adhesive, thereby manufacturing a polarizing plate.

Example 2

(17) A sample was manufactured by the same method as described in Example 1, except that 10 parts by weight of the second resin obtained in Preparation Example 2 was mixed with 90 parts by weight of the first resin which was the same as used in Example 1.

Example 3

(18) A sample was manufactured by the same method as described in Example 1, except that 10 parts by weight of the second resin obtained in Preparation Example 3 was mixed with 90 parts by weight of the first resin which was the same as used in Example 1.

Example 4

(19) A sample was manufactured by the same method as described in Example 1, except that 10 parts by weight of the second resin obtained in Preparation Example 4 was mixed with 90 parts by weight of the first resin which was the same as used in Example 1.

Example 5

(20) A sample was manufactured by the same method as described in Example 1, except that 10 parts by weight of the second resin obtained in Preparation Example 5 was mixed with 90 parts by weight of the first resin which was the same as used in Example 1.

Example 6

(21) A sample was manufactured by the same method as described in Example 1, except that 10 parts by weight of the second resin obtained in Preparation Example 6 was mixed with 90 parts by weight of the first resin which was the same as used in Example 1.

Comparative Example 1

(22) An extrusion film was manufactured by drying 100 parts by weight of the pellet of the first resin used in Example 1 in an oven and extruding the pellet by the same method as described in Example 1. An extension film was manufactured by extending the extrusion film by the same method as described in Example 1.

Comparative Example 2

(23) A sample was manufactured by the same method as described in Example 1, except that 10 parts by weight of the second resin obtained in Preparation Example 7 was mixed with 90 parts by weight of the first resin which was the same as used in Example 1.

Comparative Example 3

(24) A sample was manufactured by the same method as described in Example 1, except that 10 parts by weight of the second resin obtained in Preparation Example 8 was mixed with 90 parts by weight of the first resin which was the same as used in Example 1.

Comparative Example 4

(25) A sample was manufactured by the same method as described in Example 1, except that 10 parts by weight of the second resin obtained in Preparation Example 9 was mixed with 90 parts by weight of the first resin which was the same as used in Example 1.

Comparative Example 5

(26) A sample was manufactured by the same method as described in Example 1, except that 10 parts by weight of the second resin obtained in Preparation Example 10 was mixed with 90 parts by weight of the first resin which was the same as used in Example 1.

(27) Physical properties in Examples and Comparative Examples were evaluated by the following methods.

(28) 1. Measurement of Optical Characteristics (Haze and Transmittance)

(29) Haze and a transmittance of an extension film were measured using a haze meter HM-150 (Murakami Color Research Laboratory).

(30) 2. Measurement of Melt Viscosity

(31) A melt viscosity was measured using a capillary rheometer 1501 (Gottfert).

(32) Specifically, a capillary die was attached to a barrel, and resins obtained in the examples or comparative examples were filled over three times. In addition, a shear viscosity (pa*s) according to a shear rate at a processing temperature of 250 C. was measured.

(33) 3. Measurement of Adhesive Strength

(34) To evaluate an adhesive strength between a polarizer and a protective film in a polarizing plate, the polarizing plate having a width of 18 mm was prepared. Specifically, the polarizing plate was prepared by adhering the samples prepared in the examples or comparative examples as a protective film using a cation- and radical-polymerized adhesive to one surface of the polarizer manufactured by extending a polyvinylalcohol-based resin film, dying the extended film with iodine and treating the dyed film with a boric acid aqueous solution such that a second resin layer of the sample was disposed to face the polarizer. A peeling strength at 90 of the prepared polarizing plate was measured using a texture analyzer (MHK) at 300 mm/min was measured, and as shown in FIG. 3, a peeling strength between the polarizer and the protective film was measured on a side to which UV rays were irradiated. The peeling strength was measured three times, and an average was listed.

(35) 4. Observation of Shape of Cross-Section

(36) After a low temperature impact test for the samples of the examples or comparative examples, a broken surface was etched using THF vapor, and a layer-separated cross-section was observed using an SEM (Manufacturer: Hitachi, Model name: S-4800).

(37) A shape of the observed cross-section was evaluated according to the following criteria.

(38) : the state in which complete layer separation phenomenon was observed

(39) : the state in which layer separation was not sufficiently performed

(40) x: the state in which layer separation was not performed

(41) 5. Measurement of Surface Energy

(42) Surface energy was measured using a drop shape analyzer (DAS 100, KRUSS) according to the Owens-Wendt-Rabel-Kaelble method.

(43) Specifically, the resin obtained in the examples or comparative examples was dissolved at 15 wt % in a methyl ethyl ketone solvent, and bar-coated on an LCD glass. In addition, the coated LCD glass was pre-dried in an oven at 60 C. for 2 minutes, and dried in an oven at 90 C. for 1 minute.

(44) After drying (or curing), 10 drops of deionized water and diiodomethane each were dropped on the coated surface to obtain an average of a contact angle, and the surface energy was obtained by substituting the value by the Owens-Wendt-Rabel-Kaelble method.

(45) TABLE-US-00001 TABLE 1 Difference in Adhesive Difference in surface energy Optical characteristic strength Phase melt viscosity (mN/m) Haze T(%) (N/cm.sup.2) separation (pa*s) Example 1 3 0.2 93.8 2.2 900 Example 2 5 0.2 93.7 2.5 1010 Example 3 5 0.2 93.9 2.4 990 Example 4 6 0.2 93.9 2.7 995 Example 5 5 0.2 93.6 2.3 985 Example 6 5 0.2 93.7 2.6 990 Comparative 0.2 93.9 2 x Example 1 Comparative 2 0.2 93.7 2.5 x 1140 Example 2 Comparative 9 0.2 93.8 2.2 930 Example 3 Comparative 3 0.2 93.8 2.1 920 Example 4 Comparative 3 0.2 93.7 2 915 Example 5