KR20170097536A - Polycarbonate resin composition and optical product using the same - Google Patents

Abstract

The present invention relates to a polycarbonate resin composition for light guide panels, and an optically molded article using the same. According to the present invention, the polycarbonate resin composition ensures excellent processability, color uniformity, and transmittance required in light guide panels, and thus can be useful as materials for light guide panels. To this end, the polycarbonate resin composition contains: 100 parts by weight of polycarbonate; 0.02-1 parts by weight of a block copolymer consisting of a polyethylene oxide (PEO) block represented by chemical formula 1 and a polypropylene oxide (PPO) block represented by chemical formula 2; and 0.01-5 parts by weight of a vinyl-based polymer including a (meth)acrylate repeating unit having an epoxy functional group.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycarbonate resin composition,

The present invention relates to a polycarbonate resin composition for a light guide plate excellent in transmittance, excellent in color uniformity, and excellent in workability, and an optical molded article using the polycarbonate resin composition.

In recent years, as the liquid crystal display device has become thinner and larger, the thickness of the parts used for the liquid crystal display device is getting thinner. BACKGROUND ART [0002] A liquid crystal display ("LCD") is equipped with a backlight which is a light emitting part that emits light behind a LCD, and a light guide plate or a diffusion plate for diffusing or transmitting light depending on the type of a light source is used. The thickness of the light guide plate is becoming thinner according to the recent trend, and the general level of the light guide plate actually used is about 0.5 mm, but the thinner one is about 0.3 mm, and its thickness is becoming thinner in the future.

The use of edge type backlight units equipped with LEDs in the corner portions of the backlight is increasing in place of the cold cathode fluorescent lamp (CCFL) which has been used mainly in accordance with the trend of thinning. In the edge type backlight unit, light emitted from a light source mounted on a corner portion is transmitted through a light guide plate, a part of light transmitted through the plate is scattered by a light scattering layer applied to the surface of the plate, Thereby illuminating the liquid crystal display device. Such a light scattering layer is formed by transferring or printing a dot pattern on the surface of the light guide plate. Recently, a microstructure prism structure is also transferred to increase the light efficiency.

Since the light guide plate requires a high light transmittance, it is common that PMMA, which is an acrylic resin, is used as a material of the light guide plate. The acrylic resin has a high light transmittance but has a disadvantage in that it is not suitable for application to a thin light guide plate due to its lack of mechanical strength and is insufficient in heat resistance and is vulnerable to heat generated in electronic equipment.

Polycarbonates have attracted attention in place of such acrylic resins. Polycarbonate is superior in mechanical strength to acrylic resin and can be used as a material for a thin light guide plate. The polycarbonate is also excellent in heat resistance and flame retardancy, and is gradually replacing acrylic resin in LED backlight unit and lighting apparatus having large heat generation. However, since polycarbonate has a lower total light transmittance than an acrylic resin, it is required to have a light transmittance corresponding to that of an acrylic resin while maintaining the advantages of polycarbonate.

Japanese Patent Laid-Open Publication No. 2008-045131 discloses that PMMA having a viscosity average molecular weight (Mv) of 20,000 to 60,000 in an acrylic resin is blended in a range of 0.1 to 0.3 phr in a polycarbonate having an Mv of 15,000 to 40,000 to obtain excellent photoconductivity There is a suggestion. However, the physical properties such as heat resistance still need to be improved.

Accordingly, the inventors of the present invention have been studying a material that can be used as a material for a light guide plate, and as described below, a block copolymer containing a polyethylene oxide block and a polypropylene oxide block and a (meth) acrylate repeating unit containing an epoxy functional group It has been confirmed that a polycarbonate resin composition containing a vinyl polymer at the same time is excellent in light transmittance and color stability and can be used as a material for a light guide plate.

An object of the present invention is to provide a polycarbonate resin composition for a light guide plate which is excellent in transmittance, excellent in color uniformity, and excellent in workability.

The present invention also provides an optical molded article comprising the resin composition.

In order to solve the above-mentioned problems, the present invention provides a polycarbonate resin composition comprising 100 parts by weight of a polycarbonate; 0.02 to 1 part by weight of a block copolymer comprising a polyethylene oxide (PEO) block represented by the following formula (1) and a polypropylene oxide (PPO) block represented by the following formula (2); And 0.01 to 5 parts by weight of a vinyl-based polymer containing a (meth) acrylate repeating unit containing an epoxy functional group. The polycarbonate resin composition of

[Chemical Formula 1]

(2)

In the above Formulas 1 and 2,

n and m are each independently an integer of 1 or more,

n + m is 7 to 70;

The present invention also relates to a polycarbonate composition comprising 100 parts by weight of a polycarbonate; 0.02 to 1 part by weight of a block copolymer comprising a polyethylene oxide (PEO) block represented by Formula 1 and a polypropylene oxide (PPO) block represented by Formula 2; And 0.01 to 5 parts by weight of a transmittance improving agent having an epoxy functional group, wherein the long-light transmittance measured on a specimen having a thickness of 4 mm is 80% or more.

Polycarbonate

The term " polycarbonate " used in the present invention means a polymer prepared by reacting a diphenol compound, phosgene, carbonic acid ester or a combination thereof. Polycarbonate has excellent heat resistance, impact resistance, mechanical strength and transparency, and is widely used for the manufacture of compact discs, transparent sheets, packaging materials, automobile bumpers, ultraviolet shielding films and the like. Particularly, use.

Examples of the diphenol compound include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) propane (also referred to as bisphenol- (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis Bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis Bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) Ether, and the like. Preferably, 4,4'-dihydroxydiphenyl and 2,2-bis (4-hydroxyphenyl) propane are used. In this case, the structure of the polycarbonate is represented by the following formula 3:

(3)

In Formula 3, a is an integer of 1 or more.

The polycarbonate may be a mixture of copolymers prepared from two or more diphenols. The polycarbonate may be a linear polycarbonate, a branched polycarbonate, or a polyester carbonate copolymer resin.

Examples of the linear polycarbonate include polycarbonate prepared from bisphenol-A. Examples of the branched polycarbonate include those prepared by reacting a polyfunctional aromatic compound such as trimellitic anhydride and trimellitic acid with a diphenol and a carbonate. The polyfunctional aromatic compound may be contained in an amount of 0.05 to 2 mol% based on the total amount of the branched polycarbonate. Examples of the polyester carbonate copolymer resin include those prepared by reacting a bifunctional carboxylic acid with a diphenol and a carbonate. As the carbonate, diaryl carbonate such as diphenyl carbonate, ethylene carbonate and the like can be used.

Preferably, the polycarbonate has a weight average molecular weight of 14,000 to 50,000 g / mol. The formability and workability are excellent in the production of thin film products within the above range.

Polyethylene oxide-polypropylene oxide block copolymer

On the other hand, the polycarbonate is relatively superior in mechanical properties, electrical properties, and weather resistance to other types of resins, and can be used as a light guide plate itself. However, it is necessary to improve the light transmittance which is considered to be important in the light guide plate because it is somewhat low. Therefore, in the present invention, a polyethylene oxide-polypropylene oxide block copolymer is used together with the polycarbonate.

The term " polyethylene oxide-polypropylene oxide block copolymer " used in the present invention refers to polyethylene oxide (PEO) blocks represented by the above formula (1) and polypropylene oxides represented by the above formula (2) (PPO) block, wherein n in the formula (1) is the total number of ethylene oxide repeat units in the block copolymer, and m in the formula (2) is the number of propylene oxide Means the total number of repeating units. Here, the block copolymer refers to a copolymer in which two or more homopolymer blocks are linked by covalent bonds, such as a bimodal block copolymer having two distinct blocks, a triblock copolymer having three distinct blocks Is possible. At this time, the polyethylene oxide-polypropylene oxide block copolymer may be prepared by polymerizing polyoxyethylene glycol and polyoxypropylene glycol.

There has been an attempt to improve the light transmittance in the light guide plate by adding polyoxyalkylene glycol. However, in the case of polyoxypropylene glycol, compatibility with polycarbonate is high, but since the heat resistance is low, there arises a problem that the light transmittance is lowered due to the high temperature in manufacturing the light guide plate. In addition, in the case of polyoxyethylene glycol, there is a problem of migration due to the linear structure having no substituent in the side chain.

However, the block copolymer containing both polyethylene oxide and polypropylene oxide block as in the present invention can improve both the color stability and the light transmittance because the disadvantages of the respective polyoxyalkylene glycols are complementary to each other.

According to one embodiment of the present invention, it was confirmed that both the color stability and the light transmittance of the polyethylene oxide-polypropylene oxide block copolymer-containing example were significantly improved as compared with the comparative example using polyoxyethylene glycol and polyoxypropylene glycol, respectively I could.

The polyethylene oxide-polypropylene oxide block copolymer may be a binary block copolymer or a ternary block copolymer. For example, the polyethylene oxide-polypropylene oxide block copolymer may be a binary block copolymer in the form of PEO-PPO. Alternatively, the polyethylene oxide-polypropylene oxide block copolymer may be a ternary block copolymer in the form of PEO-PPO-PEO or PPO-PEO-PPO. Of these, in the case of using a ternary block copolymer, PEO and PPO blocks having different refractive indexes are combined in the form of PEO-PPO-PEO or PPO-PEO-PPO, compared with the case of using a binary block copolymer of PEO-PPO type , It is possible to show the effect of improving the transmittance. The PEO-PPO-PEO ternary block copolymer may be represented by the following formula (4), and the PPO-PEO-PPO ternary block copolymer may be represented by the following formula (5)

[Chemical Formula 4]

[Chemical Formula 5]

In the formulas (4) and (5), p, q and r are each independently an integer of 1 or more, and p + q + r is 7 to 70.

The polyethylene oxide-polypropylene oxide block copolymer preferably has a weight average molecular weight of 500 to 10,000 g / mol, for example, 1,000 to 10,000 g / mol. Within the above range, the physical properties of the light guide plate can be effectively improved.

The polyethylene oxide-polypropylene oxide block copolymer may be included in an amount of 0.02 to 1 part by weight based on 100 parts by weight of the polycarbonate. For example, the polyethylene oxide-polypropylene oxide block copolymer may be contained in an amount of 0.05 to 1 part by weight, specifically 0.05 to 0.7 part by weight, or more specifically 0.05 to 0.5 part by weight, based on 100 parts by weight of the polycarbonate. Within this range, the light transmittance and tint stability can be improved without deteriorating the properties of the polycarbonate in the resin composition.

Epoxy group-containing vinyl-based polymer

On the other hand, the polycarbonate is relatively superior in mechanical properties, electrical properties, and weather resistance to other types of resins, and can be used as a light guide plate itself. However, it is necessary to improve the tint stability under high temperature and high humidity conditions, which should be considered important in the light guide plate. By using an epoxy group-containing vinyl polymer together with the polycarbonate, the hydrolysis of the polymer under high temperature and high humidity conditions can be suppressed.

The term "epoxy-containing vinyl polymer" used in the present invention means a vinyl-based polymer containing a (meth) acrylate repeating unit containing an epoxy functional group as a polyfunctional epoxy compound. Here, '(meth) acryl' means acryl and methacryl. That is, (meth) acrylate should be understood to mean acrylate or methacrylate.

According to an embodiment of the present invention, a vinyl-based polymer containing a (meth) acrylate repeating unit containing an epoxy functional group, as compared with a comparative example in which a vinyl-based polymer containing a (meth) It was confirmed that the color stability was maintained even after being left for a long time under high temperature and high humidity conditions.

Further, according to another embodiment of the present invention, in comparison with the comparative example using an alicyclic compound containing an epoxy functional group, the hue stability of the example using the vinyl polymer containing the (meth) acrylate repeating unit containing the epoxy functional group, It was confirmed that the transmittance was remarkably improved.

The vinyl polymer containing the (meth) acrylate repeating unit containing the epoxy functional group may be contained in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the polycarbonate. For example, the vinyl-based polymer containing the (meth) acrylate repeating unit containing the epoxy functional group is added in an amount of 0.01 to 2.5 parts by weight, specifically 0.01 to 1 part by weight, more specifically 0.01 to 1 part by weight, 0.1 part by weight, or even more specifically 0.05 part by weight to 0.1 part by weight. When the amount is less than 0.01 part by weight, the degree of color stability is not maintained in a long time under high temperature and high humidity conditions, and when the amount is more than 5 parts by weight, the properties of the polycarbonate may be deteriorated.

In addition, the vinyl-based polymer containing the (meth) acrylate repeating unit containing the epoxy functional group preferably has a weight average molecular weight of 1,000 to 10,000 g / mol. Within the above range, the physical properties of the light guide plate can be effectively improved.

Specifically, the epoxy-containing vinyl polymer may include a (meth) acrylate repeating unit containing an epoxy functional group, and in the (meth) acrylate repeating unit containing the epoxy functional group, the epoxy functional group may be a (meth) May be bonded to the branched end of the unit. The (meth) acrylate repeating unit may include a main chain formed through polymerization between vinyl-based functional groups and a branched chain extending in a branch shape from the main chain. The epoxy functional group may form a bond at the end of the branched chain of the (meth) acrylate repeating unit.

More specifically, the (meth) acrylate repeating unit containing the epoxy functional group may include a repeating unit represented by the following formula (11)

(11)

In Formula 11,

R ₁ to R ₃ are each independently hydrogen or C _1-10 alkyl, R ₄ is C _1-10 alkylene, and x is an integer of 1-20.

The alkyl or alkylene may be substituted or unsubstituted, and the 'substitution' means that a hydrogen atom contained in an alkyl group or an alkylene group is replaced with a specific functional group. Examples of the substituted functional groups are not limited to a wide variety, and various conventionally known functional groups or atomic groups such as halogen, hydroxyl, amino and the like can be used without limitation.

The epoxy-containing vinyl polymer may have an epoxy equivalent weight of 100 to 500 g / mol, or 200 to 400 g / mol. Since the epoxy group-containing vinyl polymer contains a specific amount of epoxy functional groups, excellent color stability can be maintained even after being left for a long time under high temperature and high humidity conditions.

The epoxy-containing vinyl polymer may further include an aromatic vinyl-based repeating unit or a (meth) acrylic-based repeating unit. The aromatic vinyl-based repeating unit means a repeating unit derived from an aromatic vinyl-based monomer, and specifically means a repeating unit constituting a polymer formed through polymerization between aromatic vinyl-based monomers. That is, the epoxy-containing vinyl polymer includes, for example, a (meth) acrylate repeating unit containing an epoxy functional group; An aromatic vinyl-based repeating unit; And a (meth) acrylic repeating unit.

The aromatic vinyl monomer is a compound having one vinylic double bond and at least one benzene nucleus in the same molecule. Specific examples of the aromatic vinyl monomer include, but are not limited to, styrene, alpha-methylstyrene, 2 -Methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-ethylstyrene, t-butylstyrene, 2,5-dimethylstyrene, 1,3-dimethylstyrene, , 4-ethoxystyrene, 4-propoxystyrene, 4-butoxystyrene, chlorostyrene, dichlorostyrene, trichlorostyrene, vinyltoluene, bromostyrene, dibromostyrene, tribromostyrene, vinylnaphthalene, iso Propenyl naphthalene, isopropenyl biphenyl, divinyl benzene, alpha-methyl styrene vinyl toluene and the like.

More specifically, the aromatic vinyl-based resin may include a repeating unit represented by the following formula (12)

[Chemical Formula 12]

In Formula 12,

R ₅ to R ₈ are each independently hydrogen or C _1-10 alkyl, and y is an integer of 1 to 20. The R ₈ functional group may be bonded to at least one of the carbon atoms 2 to 6 excluding the carbon atom 1 to which the vinyl group is bonded in the benzene ring. For example, the R ₈ functional group may be bonded to carbon number 4.

The alkyl may be substituted or unsubstituted, and the 'substitution' means that a hydrogen atom contained in an alkyl group is replaced with a specific functional group. Examples of the substituted functional groups are not limited to a wide variety, and various conventionally known functional groups or atomic groups such as halogen, hydroxyl, amino and the like can be used without limitation.

The (meth) acrylic repeating unit means a repeating unit derived from a (meth) acrylic monomer, and specifically means a repeating unit constituting a polymer formed through polymerization between (meth) acrylic monomers. The (meth) acrylic monomer refers to a compound containing a (meth) acryl functional group. The specific examples thereof are not particularly limited, and examples thereof include a (meth) acrylate compound or a (meth) acrylic acid compound.

More specifically, the (meth) acrylic repeating unit may include a repeating unit represented by the following formula (13).

[Chemical Formula 13]

In Formula 13,

R ₁₁ to R ₁₄ are each independently hydrogen or C _1-10 alkyl, and z is an integer of 1 to 20.

The alkyl may be substituted or unsubstituted, and the 'substitution' means that a hydrogen atom contained in an alkyl group is replaced with a specific functional group. Examples of the substituted functional groups are not limited to a wide variety, and various conventionally known functional groups or atomic groups such as halogen, hydroxyl, amino and the like can be used without limitation.

Transmittance improving agent having epoxy functional group

On the other hand, the polycarbonate resin composition may further include a transmittance improving agent having an epoxy functional group together with the polycarbonate and the polyethylene oxide-polypropylene oxide block copolymer so as to exhibit not only excellent color stability but also an improved light transmittance.

Specifically, in the case of the polycarbonate resin composition containing the transmittance improving agent having an epoxy functional group, the long-light transmittance measured on a specimen having a thickness of 4 mm may be 80% or more. At this time, the long-light transmittance can be measured using a spectrophotometer such as U-4100 manufactured by Hitachi.

As the transmittance improving agent having an epoxy functional group, a compound having at least one epoxy functional group introduced into the molecule may be used. Specifically, the transmittance improving agent having an epoxy functional group may include a vinyl-based polymer containing a (meth) acrylate repeating unit including the above-mentioned epoxy functional group. More specifically, the transmittance improving agent having an epoxy functional group may be a vinyl-based polymer containing a (meth) acrylate repeating unit containing the above-mentioned epoxy functional group.

The transmittance improving agent having an epoxy functional group may be included in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the polycarbonate. For example, the transmittance improving agent having an epoxy functional group may be included in an amount of 0.01 to 2.5 parts by weight, specifically 0.01 to 1 part by weight, based on 100 parts by weight of the polycarbonate.

Polyoxytetramethylene glycol

On the other hand, when the polycarbonate resin composition is used as a light guide plate, the resin composition may further contain polyoxytetramethylene glycol in order to further improve color stability and light transmittance.

The term " polyoxytetramethylene glycol " used in the present invention is a polymer represented by the following formula (6), which can be produced by ring-opening polymerization of tetrahydrofuran:

[Chemical Formula 6]

In Formula 6,

b is an integer of 1 or more, and is 7 to 140;

The polyoxytetramethylene glycol preferably has a weight average molecular weight of 500 to 10,000 g / mol. Within the above range, the physical properties of the light guide plate can be effectively improved.

The polyoxytetramethylene glycol may be included in an amount of 0.02 to 1 part by weight based on 100 parts by weight of the polycarbonate. For example, the polyoxytetramethylene glycol may be contained in an amount of 0.05 to 1 part by weight, specifically 0.05 to 0.7 part by weight, more specifically 0.05 to 0.5 part by weight, based on 100 parts by weight of the polycarbonate. Within this range, the light transmittance can be further improved without deteriorating the properties of the polycarbonate in the resin composition.

Polycarbonate resin composition

The polycarbonate resin composition according to the present invention comprises 100 parts by weight of a polycarbonate; 0.02 to 1 part by weight of a block copolymer comprising a polyethylene oxide (PEO) block represented by Formula 1 and a polypropylene oxide (PPO) block represented by Formula 2; And 0.01 to 5 parts by weight of a vinyl-based polymer containing a (meth) acrylate repeating unit containing an epoxy functional group.

Alternatively, the polycarbonate resin composition according to the present invention comprises 100 parts by weight of a polycarbonate; 0.02 to 1 part by weight of a block copolymer comprising a polyethylene oxide (PEO) block represented by Formula 1 and a polypropylene oxide (PPO) block represented by Formula 2; And 0.01 to 5 parts by weight of a transmittance enhancer having an epoxy functional group. At this time, the polycarbonate resin composition has a long-light transmittance of 80% or more as measured on a specimen having a thickness of 4 mm.

If necessary, the resin composition may further contain additives such as antioxidants, heat stabilizers, plasticizers, antistatic agents, nucleating agents, flame retardants, lubricants, impact modifiers, fluorescent whitening agents, ultraviolet absorbers, And at least one additive selected from the group consisting of

The resin composition may be prepared by mixing a polycarbonate, a polyethylene oxide-polypropylene oxide block copolymer, an epoxy-containing vinyl-based polymer and, if necessary, an additive, and, as will be described below, .

The melt kneading is carried out by a method commonly used in the art, for example, a method using a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, a single screw extruder, a twin screw extruder, a cone . The temperature of the melt-kneading can be appropriately adjusted as needed, and preferably 200 to 300 ° C.

Optical molding product

The present invention also provides an optical molded article comprising the resin composition. Preferably, the optical molded article is a light guide plate.

The term " light guide plate " used in the present invention means a component that performs the brightness and the uniform lighting function of the backlight unit of the liquid crystal display device. Since light is transmitted through the light guide plate, transparency, that is, light transmittance should be excellent. In addition, high heat resistance is required because a molding temperature of the light guide plate and a high temperature during operation are required.

Accordingly, the resin composition according to the present invention is excellent in light transmittance and heat resistance required for a light guide plate, and thus can be usefully used as a light guide plate. Specifically, the resin composition exhibits a long-light transmittance of 80% or more and a long-light-emitting color tone of 11 or less when measured on a specimen having a thickness of 4 mm, and is suitable for use as a material for a light guide plate.

The manufacturing method of the light guide plate can be manufactured by a method commonly used in the art. For example, the melt-kneaded material or the pellet of the resin composition according to the present invention can be used as a raw material for injection molding, injection compression molding, extrusion molding, vacuum molding, blow molding, press molding, pressure molding, foam molding, The light guide plate can be manufactured by applying a molding method such as a calender molding method and a rotary molding method.

The thickness of the light guide plate can be appropriately adjusted according to the purpose of use, and the shape of the light guide plate can be in the form of a flat plate or a curved surface depending on the purpose of use.

The polycarbonate resin composition according to the present invention is excellent in transmittance and color uniformity required in a light guide plate and is excellent in workability and can be usefully used as a material for a light guide plate.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited thereto.

Materials Used

The following materials were used in the following Examples and Comparative Examples.

- Polycarbonate resin (PC)

A bisphenol A type linear polycarbonate having a weight average molecular weight of 16,000 g / mol and MFR (300 캜 1.2 kg) of 120 g / min was used.

- PEO-PPO-PEO block copolymer (PEO-PPO-PEO)

PEO-PPO-PEO block copolymer of Aldrich having a weight average molecular weight of 2,000 g / mol was used.

- PPO-PEO-PPO block copolymer (PPO-PEO-PPO)

A PPO-PEO-PPO block copolymer of Aldrich having a weight average molecular weight of 2,000 g / mol was used.

- polyoxypropylene glycol (PPG)

Uniol D-2000 manufactured by NOF Corporation having a weight average molecular weight of 2,000 g / mol was used.

- polyoxyethylene glycol (PEG)

PEG of Aldrich Corp. having a weight average molecular weight of 2,000 g / mol was used.

- polyoxytetramethylene glycol (PTMG)

PTMG 2000 manufactured by KPX Chemical Co., Ltd. having a weight average molecular weight of 2,000 g / mol was used.

- Epoxy group-containing vinyl polymer

Joncryl ADR-4370F (epoxy equivalent weight: 285 g / mol) manufactured by BASF having a weight average molecular weight of 6,800 g / mol was used.

-Ethoxy group-containing compound

As the polyfunctional epoxy compound which is not a vinyl-based polymer, C2021P of Daicel Corporation represented by the following formula (7) was used.

(7)

- Antioxidant

DP9228 from Dover Chemical Corporation was used.

Examples and Comparative Examples

Pellet samples were prepared at a rate of 80 kg per hour in a twin screw extruder (L / D = 36, Φ = 45, barrel temperature: 240 ° C.) after mixing the respective components as shown in Table 1 below.

Unit (g) PC PEO-PPO
-PEO PPO-PEO
-PPO PPG PEG PTMG ADR
-4370F C2021P DP9228 Example 1 100 0.15 0.075 0.075 Example 2 100 0.075 0.075 0.075 0.075 Example 3 100 0.15 0.075 0.075 Example 4 100 0.075 0.075 0.075 0.075 Comparative Example 1 100 0.15 0.075 0.075 Comparative Example 2 100 0.075 0.075 0.075 0.075 Comparative Example 3 100 0.15 0.075 0.075 Comparative Example 4 100 0.075 0.075 0.075 0.075 Comparative Example 5 100 0.15 0.075 Comparative Example 6 100 0.15 0.075 Comparative Example 7 100 0.15 0.075 0.075 Comparative Example 8 100

The pellets were measured for physical properties in the following manner.

Each of the specimens (length / length / thickness = 150 mm / 80 mm / 4 mm) was injection-molded and irradiated in a direction perpendicular to the thickness with Hitachi Spectrophotometer U-4100 And the transmittance (long-light transmittance) and color stability (long-light hue) were measured.

The results are shown in Table 2 below.

Long-term light transmittance (T%) Long light hue (YI) Example 1 80.27 10.6 Example 2 81.23 10.2 Example 3 80.70 10.11 Example 4 82.30 9.98 Comparative Example 1 78.42 11.32 Comparative Example 2 77.82 12.39 Comparative Example 3 76.24 12.13 Comparative Example 4 77.69 13.01 Comparative Example 5 77.51 12.05 Comparative Example 6 76.42 11.87 Comparative Example 7 78.22 12.01 Comparative Example 8 71.91 29.3

As shown in Table 2, it can be confirmed that the examples according to the present invention are superior to the comparative examples in terms of long-range color tone and long-wavelength transmittance. Specifically, the polycarbonate resin composition of the examples shows a long-light color tone of not more than 11 and a long-wavelength light transmittance of not less than 80% with respect to a specimen having a thickness of 4 mm. In particular, it was confirmed that all the characteristics were improved as compared with Comparative Examples 1 and 3 using polyoxypropylene glycol (PPG) and polyoxyethylene glycol (PEG), respectively.

It was also found that Examples 3 and 4 in which PEO-PPO-PEO or PPO-PEO-PPO block copolymer and polyoxytetramethylene glycol (PTMG) were used at the same time were more effective in improving the long-wavelength color tone and long-wavelength light transmittance . This is in contrast to Comparative Examples 2 and 4 in which polyoxypropylene glycol (PPG) and polyoxyethylene glycol (PEG) were used simultaneously with PTMG, respectively, compared with Comparative Examples 1 and 3 using only PPG and PEG .

In addition, Comparative Example 7 using the PPO-PEO-PPO block copolymer and the alicyclic epoxy compound C2021P at the same time exhibited reduced transmittance and color stability compared to Example 3. As a result, it can be seen that when a vinyl polymer containing a (meth) acrylate repeating unit containing an epoxy functional group in the polyfunctional epoxy compound is added simultaneously with the PPO-PEO-PPO block copolymer, the effect of improving the physical properties of the light guide plate is excellent.

Therefore, it was confirmed that the resin composition according to the present invention can improve all the necessary characteristics in the light guide layer by using the polyethylene oxide-polypropylene oxide block copolymer and the epoxy-containing vinyl polymer together.

Claims (19)

100 parts by weight of polycarbonate;
0.02 to 1 part by weight of a block copolymer comprising a polyethylene oxide (PEO) block represented by the following formula (1) and a polypropylene oxide (PPO) block represented by the following formula (2); And
0.01 to 5 parts by weight of a vinyl-based polymer containing a (meth) acrylate repeating unit containing an epoxy functional group.
[Chemical Formula 1]

(2)

In this formula,
n and m are each independently an integer of 1 or more,
n + m is 7 to 70;
The method according to claim 1,
Wherein the polycarbonate has a weight average molecular weight of 14,000 to 50,000 g / mol.
The method according to claim 1,
Wherein the polycarbonate comprises a repeating unit represented by the following Formula 3:
(3)

In Formula 3, a is an integer of 1 or more.
The method according to claim 1,
Wherein the block copolymer is a block copolymer in the form of PEO-PPO-PEO or PPO-PEO-PPO.
The method according to claim 1,
Wherein the block copolymer has a weight average molecular weight of 500 to 10,000 g / mol.
The method according to claim 1,
Wherein the block copolymer is contained in an amount of 0.05 to 0.5 parts by weight, and the vinyl polymer is contained in an amount of 0.01 to 0.1 parts by weight.
The method according to claim 1,
Wherein the epoxy functional group is bonded to the branched end of the repeating unit of the (meth) acrylate.
The method according to claim 1,
Wherein the (meth) acrylate repeating unit containing the epoxy functional group comprises a repeating unit represented by the following formula (11):
(11)

In Formula 11,
R ₁ to R ₃ are each independently hydrogen or C _1-10 alkyl, R ₄ is C _1-10 alkylene, and x is an integer of 1-20.
The method according to claim 1,
Wherein the vinyl-based polymer further comprises an aromatic vinyl-based repeating unit or a (meth) acrylic-based repeating unit.
10. The method of claim 9,
Wherein the aromatic vinyl-based repeating unit comprises a repeating unit represented by the following formula (12):
[Chemical Formula 12]

In Formula 12,
R ₅ to R ₈ are each independently hydrogen or C _1-10 alkyl, and y is an integer of 1 to 20.
10. The method of claim 9,
Wherein the (meth) acrylic repeating unit comprises a repeating unit represented by the following formula (13):
[Chemical Formula 13]

In Formula 13,
R ₁₁ to R ₁₄ are each independently hydrogen or C _1-10 alkyl, and z is an integer of 1 to 20.
The method according to claim 1,
The vinyl-based polymer containing a (meth) acrylate repeating unit containing an epoxy functional group has a weight average molecular weight of 1,000 to 10,000 g / mol.
The method according to claim 1,
The vinyl-based polymer containing the (meth) acrylate repeating unit containing an epoxy functional group is a polycarbonate resin composition having an epoxy equivalent weight of 100 to 500 g / mol
The method according to claim 1,
And 0.02 to 1 part by weight of polyoxytetramethylene glycol.
The method according to claim 1,
The resin composition may further comprise at least one additive selected from the group consisting of an antioxidant, a heat stabilizer, a plasticizer, an antistatic agent, a nucleating agent, a flame retardant, a lubricant, an impact modifier, a fluorescent whitening agent, an ultraviolet absorber, ≪ / RTI >
100 parts by weight of polycarbonate;
0.02 to 1 part by weight of a block copolymer comprising a polyethylene oxide (PEO) block represented by the following formula (1) and a polypropylene oxide (PPO) block represented by the following formula (2); And
0.01 to 5 parts by weight of a transmittance improving agent having an epoxy functional group,
A polycarbonate resin composition having a long-light transmittance of 80% or more as measured on a specimen having a thickness of 4 mm;
[Chemical Formula 1]

(2)

In this formula,
n and m are each independently an integer of 1 or more,
n + m is 7 to 70;
17. The method of claim 16,
Wherein the transmittance improving agent having an epoxy functional group comprises a vinyl-based polymer containing a (meth) acrylate repeating unit containing an epoxy functional group.
An optical molded article comprising the polycarbonate resin composition according to any one of claims 1 to 17.
19. The method of claim 18,
Wherein the optical molded article is a light guide plate.