Resin composition and method for preparing same

Abstract

A resin composition according to one embodiment of the present invention comprises: a graft copolymer including a conjugated diene-based polymer, an aromatic vinyl-based monomer unit, and a vinyl cyan-based monomer unit; a matrix copolymer including an aromatic vinyl-based monomer unit and a vinyl cyan-based monomer unit; and a cross-linked copolymer including a cross-linked part formed from an aromatic vinyl-based monomer unit, a vinyl cyan-based monomer unit, and a cross-linked functional compound, wherein the particle diameter (D50) at which the cumulative percentage by weight in the particle size distribution of the cross-linked copolymer reaches 50% is 30 μm to 60 μm, an average H-W ratio of the cross-linked copolymer satisfies Mathematical Formula 1 below, and a light reflection variation coefficient calculated by Mathematical Formula 2 below may be 1.35 or less. [Mathematical Formula 1] 0.09 ≤ average H-W ratio ≤ 1, wherein the average H-W ratio is an average value of H-W ratios (a / b) calculated for each cross-linked copolymer observed when the surface of the resin composition is observed with an optical microscope, a is ½ of the shortest axis length of each cross-linked copolymer observed when observed with the optical microscope, and b is the longest axis length of each cross-linked copolymer observed when observed with the optical microscope. [Mathematical Formula 2] CLR = DL / ML, wherein CLR is the light reflection variation coefficient, DL is the standard deviation of light intensity, and ML is the average light intensity.

Description

Resin composition and method for producing the same

[0001] [Cross-reference with related applications]

[0002] This application claims the benefit of priority to Korean Patent Application No. 2023-0142384, filed October 23, 2023, the entire contents of which are incorporated herein by reference.

[0003]

[0004] [Technical Field]

[0005] The present invention relates to a resin composition and a method for producing the same.

[0006] Acrylonitrile-butadiene-styrene (ABS) copolymers are manufactured by grafting styrene and acrylonitrile onto a rubbery butadiene polymer. ABS copolymers offer a balanced combination of rigidity, chemical resistance, impact resistance, and processability. They also boast excellent impact strength, mechanical properties, surface gloss, and secondary processing characteristics, such as plating, printing, and painting. They also offer the advantage of being able to produce products in a variety of colors.

[0007] Moreover, recently, the demand for plastics with a matte finish has been increasing to improve the appearance of products. To this end, methods are known for manufacturing sheets by coextruding polymethyl methacrylate (PMMA) particles with ABS resin as a substrate layer, extruding sheets using a cross-linked polymer as a matting agent through reactive extrusion, or mixing in crystalline polymers such as syndiotactic polystyrene (sPS) or polyamide (PA). However, when manufacturing using the above-mentioned manufacturing methods, there are problems such as a significant deterioration in the mechanical properties of the resin composition or a decrease in processability.

[0008] [Prior Art Literature]

[0009] [Patent Document]

[0010] (Patent Document 0001) JP 6571542 B2

[0011] The problem to be solved by the present invention is to provide a resin composition having high mechanical properties and high surface uniformity while having a matte characteristic.

[0012] Another problem to be solved by the present invention is to provide a method for producing a resin composition having high mechanical properties and high surface uniformity while having a matte characteristic.

[0013] (1) The present invention comprises a graft copolymer comprising a conjugated diene polymer, an aromatic vinyl monomer unit, and a vinyl cyan monomer unit; a matrix copolymer comprising an aromatic vinyl monomer unit and a vinyl cyan monomer unit; and a crosslinked copolymer comprising a crosslinking moiety formed from an aromatic vinyl monomer unit, a vinyl cyan monomer unit, and a crosslinking functional compound, wherein the particle diameter (D) when the weight-based cumulative percentage on the particle size distribution of the crosslinked copolymer reaches 50% 50 ) is 30 ㎛ or more and 60 ㎛ or less, the average HW ratio of the crosslinked copolymer satisfies the following mathematical formula 1, and the light reflection variation coefficient calculated by the following mathematical formula 2 is 1.35 or less.

[0014] [Mathematical Formula 1]

[0015] 0.09≤ Average HW ratio ≤1

[0016] In the above mathematical expression 1, the average HW ratio is the average value of the HW ratio (a / b) calculated for each crosslinked copolymer observed when the surface of the resin composition is observed with an optical microscope,

[0017] The above a is ½ the value of the shortest axis length of each cross-linked copolymer observed when observed with an optical microscope,

[0018] The above b is the longest axis length of each crosslinked copolymer observed when observed with an optical microscope.

[0019] [Equation 2]

[0020] C LR = D L / M L

[0021] C above LR is the coefficient of variation of light reflection, and D L is the standard deviation of luminosity, and M L is the average luminosity.

[0022] (2) In the present invention, in the above (1), the particle diameter (D) when the weight-based cumulative percentage of the crosslinked copolymer reaches 50% 50 ) provides a resin composition having a particle size of 30 ㎛ or more and 50 ㎛ or less.

[0023] (3) The present invention provides a resin composition in which, in the above (1) or (2), the crosslinking functional compound forming the crosslinking portion of the crosslinked copolymer is an acrylate compound or an allyl compound.

[0024] (4) The present invention provides a resin composition in which, in the above (1) to (3), the crosslinking functional compound forming the crosslinking portion of the crosslinked copolymer is allyl methacrylate.

[0025] (5) The present invention provides a resin composition having a gloss of 7.5 or less at 60° as measured by a gloss meter according to the evaluation method of ASTM D523 in (1) to (4).

[0026] (6) The present invention provides a resin composition comprising, in (1) to (5), the crosslinked copolymer in an amount of 10 parts by weight or more and 35 parts by weight or less, and the matrix copolymer in an amount of 48 parts by weight or more and 63 parts by weight or less, based on 100 parts by weight of the total of the graft copolymer, the matrix copolymer, and the crosslinked copolymer.

[0027] (7) The present invention relates to a particle size distribution diagram in which the cumulative percentage based on weight reaches 50% (D 50 ) is 60 ㎛ or less and an average HW ratio satisfies the following mathematical formula 1; and a step (S2) of mixing the crosslinked copolymer prepared in step S1; a conjugated diene polymer; a graft copolymer comprising an aromatic vinyl monomer unit and a vinyl cyan monomer unit; and a matrix copolymer comprising an aromatic vinyl monomer unit and a vinyl cyan monomer unit, wherein step S1 comprises: a step (S1-1) of initiating a polymerization reaction by introducing an aromatic vinyl monomer, a vinyl cyan monomer, and a polymerization initiator into a reactor; and a step (S1-2) of polymerizing a crosslinking functional compound by dividing it into the reactor after step S1.

[0028] [Mathematical Formula 1]

[0029] 0.09≤ Average HW ratio ≤1 In the above mathematical expression 1, the average HW ratio is the average value of the HW ratio (a / b) calculated for each crosslinked copolymer observed when the surface of the resin composition is observed with an optical microscope,

[0030] The above a is ½ the value of the shortest axis length of each cross-linked copolymer observed when observed with an optical microscope,

[0031] The above b is the longest axis length of each crosslinked copolymer observed when observed with an optical microscope.

[0032] (8) The present invention provides a method for manufacturing a resin composition, wherein, in the above (7), the step S1 further includes a step (S1-3) of crushing the resultant product of the step S1-2.

[0033] The resin composition according to the present invention has a matte characteristic and excellent mechanical properties and surface uniformity.

[0034] The manufacturing method according to the present invention can provide a resin composition having a matte characteristic and excellent mechanical properties and surface uniformity.

[0035] Hereinafter, the present invention will be described in more detail to help understand the present invention.

[0036] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0037]

[0038] The terms and measurement methods used in the present invention may be defined as follows unless otherwise defined.

[0039] The term 'composition' as used in the present invention includes a mixture of materials comprising the composition as well as reaction products and decomposition products formed from the materials of the composition.

[0040] The term 'monomer unit', 'crosslinking unit', or 'crosslinking portion' used in the present invention may mean a repeating unit formed by a compound used as a monomer or a compound used as a crosslinking agent participating in a polymerization reaction or a crosslinking reaction, a structure resulting therefrom, or the material itself.

[0041] The term 'derivative' used in the present invention may refer to a compound having a structure in which at least one of the hydrogen atoms constituting the original compound is substituted with a halogen group, an alkyl group, or a hydroxy group.

[0042]

[0043] Resin composition

[0044] The present invention provides a resin composition.

[0045] The resin composition according to the present invention comprises at least a graft copolymer comprising a conjugated diene polymer, an aromatic vinyl monomer unit, and a vinyl cyan monomer unit; a matrix copolymer comprising an aromatic vinyl monomer unit and a vinyl cyan monomer unit; and a crosslinked copolymer comprising a crosslinking moiety formed from an aromatic vinyl monomer unit, a vinyl cyan monomer unit, and a crosslinking functional compound, wherein the particle diameter (D) when the weight-based cumulative percentage on the particle size distribution of the crosslinked copolymer reaches 50% 50 ) is 30 ㎛ or more and 60 ㎛ or less, the average HW ratio of the crosslinked copolymer satisfies the following mathematical formula 1, and the light reflection variation coefficient calculated by the following mathematical formula 2 is 1.35 or less.

[0046] [Mathematical Formula 1]

[0047] 0.09≤ Average HW ratio ≤1

[0048] In the above mathematical expression 1, the average HW ratio is the average value of the HW ratio (a / b) calculated for each crosslinked copolymer observed when the surface of the resin composition is observed with an optical microscope,

[0049] The above a is ½ the value of the shortest axis length of each cross-linked copolymer observed when observed with an optical microscope,

[0050] The above b is the longest axis length of each crosslinked copolymer observed when observed with an optical microscope.

[0051] [Equation 2]

[0052] C LR = D L / M L

[0053] In the above mathematical expression 2, C LR is the coefficient of variation of light reflection, and D L is the standard deviation of luminosity, and M L is the average luminosity.

[0054]

[0055] Conventional matte products typically involve roughening the surface of an injection mold with a corrosion treatment, then injecting resin to create a diffusely reflective surface. However, this method presents challenges in achieving a practical matte finish, and the resulting wear on the injection mold reduces processability, making it unsuitable for mass production.

[0056] Meanwhile, some molded products attempt to achieve a matte finish through post-processing. For example, a film containing a crosslinker is co-extruded and applied to create a pattern on the surface. Another method involves applying a crosslinker to the product and then UV curing it to create a pattern on the surface. However, these methods have limitations in the achievable gloss level and suffer from poor surface uniformity.

[0057] Gloss is a representative value that can express the gloss (high gloss, low gloss) or matte of a resin. In general, commercially available matte molded products have a gloss value exceeding 30, which cannot be considered practically matte. However, when using the resin composition of the present invention, gloss can be implemented at a very low level, making it possible to implement a matte product.

[0058] In addition, according to one embodiment of the present invention, the resin composition has low gloss and a low coefficient of variation of light reflection, so that it is possible to provide a matte molded product with a uniform surface, and has excellent mechanical properties. These characteristics can be realized by including an aromatic vinyl-vinyl cyan-acrylic crosslinked copolymer having a specific average particle size range, and problems of existing matte molded products can be solved through this crosslinked copolymer.

[0059]

[0060] According to one embodiment of the present invention, the resin composition may have a glossiness at 60° measured by a gloss meter according to the evaluation method of ASTM D523 of 7.5 or less, and for specific examples, it may be 7.4 or less, 7.3 or less, 7.2 or less, 7.1 or less, or 7 or less.

[0061]

[0062] The resin composition according to one embodiment of the present invention may have an Izod impact strength of 18 kg·cm / cm or more, measured on a 1 / 4'' specimen by the evaluation method of ASTM D256, and for specific examples, may be 18.2 kg·cm / cm or more, 18.4 kg·cm / cm or more, 18.6 kg·cm / cm or more, 18.8 kg·cm / cm or more, or 19 kg·cm / cm or more.

[0063]

[0064] According to one embodiment of the present invention, the resin composition may have a flow index of 10 g / 10 min or more as measured under the conditions of 220°C and 10 kg by the evaluation method of ASTM D1238, and for specific examples, may be 10.2 g / 10 min or more, 10.4 g / 10 min or more, 10.6 g / 10 min or more, 10.8 g / 10 min or more, or 11 g / 10 min or more.

[0065]

[0066] Hereinafter, each component included in the above resin composition will be described in detail.

[0067]

[0068] 1. Crosslinked copolymer

[0069] According to one embodiment of the present invention, the crosslinked copolymer imparts surface properties to the resin composition such that light can be diffusely reflected from the surface. Due to crosslinking, the crosslinked copolymer is manufactured in a form with higher strength and can be uniformly distributed within the matrix resin. When the crosslinked copolymer is included in the resin composition, the gloss and light reflection coefficient of variation can be implemented with very low levels, while the impact strength can be improved to an excellent level.

[0070] According to one embodiment of the present invention, the crosslinked copolymer may be included in an amount of 10 parts by weight or more and 35 parts by weight or less, based on 100 parts by weight of the resin composition, and more specifically, may be included in an amount of 11 parts by weight or more, 12 parts by weight or more, 13 parts by weight or more, 14 parts by weight or more, or 15 parts by weight or more, and may also be included in an amount of 34 parts by weight or less, 33 parts by weight or less, 32 parts by weight or less, 31 parts by weight or less, or 30 parts by weight or less. When the crosslinked copolymer is included in the above range, the gloss and the coefficient of variation of light reflection can be implemented with very low values, while the impact strength can be improved to a superior level.

[0071]

[0072] According to one embodiment of the present invention, the crosslinked copolymer may include a crosslinking portion formed from a crosslinking functional compound, an aromatic vinyl monomer unit, and a vinyl cyan monomer unit.

[0073] The above crosslinked copolymer may be a random copolymer, and the composition of the aromatic vinyl monomer units and vinyl cyan monomer units within the copolymer may be uniform. The uniform composition of the monomer units may mean that the ratio of each monomer unit present in the polymer that is polymerized and grows by the polymerization reaction of the monomer is maintained uniformly. As a specific example, as the polymerization progresses, that is, when a portion of the polymer in the reactor is collected according to changes in the polymerization time during the polymerization, the ratio of each monomer unit forming the polymer may be maintained uniformly.

[0074] According to one embodiment of the present invention, the aromatic vinyl monomer unit and the vinyl cyan monomer unit may refer to repeating units formed by the aromatic vinyl monomer and the vinyl cyan monomer participating in a polymerization reaction, respectively. As a specific example, the polymerization reaction may be a radical polymerization reaction, and thus, may refer to repeating units derived from carbon-carbon double bonds present in the aromatic vinyl monomer and the vinyl cyan monomer.

[0075]

[0076] According to one embodiment of the present invention, the cross-linking portion may include a cross-linking functional compound unit formed by a cross-linking functional compound, and the cross-linking functional compound may include at least one selected from the group consisting of an acrylic compound and an allyl compound.

[0077] A crosslinked copolymer according to one embodiment of the present invention may have crosslinking units very uniformly distributed therein, and the degree of distribution of the crosslinking units may be appropriate, so that the fluidity between the entire chains is alive.

[0078] According to one embodiment of the present invention, the crosslinking functional compound may include at least one selected from the group consisting of acrylic compounds and aryl compounds as described above, and may include a functional group such as a vinyl group or an acrylic group, and specifically, at least one selected from the group consisting of divinylbenzene, trivinylbenzene, ethylene glycol di(meth)acrylate, allyl (meth)acrylate, diallyl phthalate, diallyl maleate, triallyl isocyanurate, and trialkyl isocyanurate may be applied, and may be divinylbenzene or allyl methacrylate.

[0079] According to one embodiment of the present invention, the crosslinked copolymer may contain the crosslinking unit in an amount of 0.05 parts by weight or more and 5 parts by weight or less, based on 100 parts by weight of the total of the aromatic vinyl monomer unit and the vinyl cyan monomer unit, and more specifically, it may contain 0.055 parts by weight or more, 0.06 parts by weight or more, 0.065 parts by weight or more, 0.07 parts by weight or more, 0.075 parts by weight or more, or 0.08 parts by weight or more, and further, it may contain 4.5 parts by weight or less, 4 parts by weight or less, 3.5 parts by weight or less, 3 parts by weight or less, 2.5 parts by weight or less, or 2 parts by weight or less. When the above range is satisfied, the degree of crosslinking can be implemented at an appropriate level.

[0080]

[0081] According to one embodiment of the present invention, the aromatic vinyl monomer for forming the aromatic vinyl monomer unit included in the crosslinked copolymer may be at least one selected from the group consisting of styrene, α-methylstyrene, α-ethylstyrene, p-methylstyrene, o-methylstyrene, ot-butylstyrene, bromostyrene, chlorostyrene, trichlorostyrene, and derivatives thereof, and a specific example thereof may be styrene.

[0082] According to one embodiment of the present invention, the crosslinked copolymer may contain 60 parts by weight or more and 85 parts by weight or less of the aromatic vinyl monomer unit, based on 100 parts by weight of the total of the aromatic vinyl monomer unit and the vinyl cyan monomer unit, and for more specific examples, it may contain 62 parts by weight or more, 64 parts by weight or more, 66 parts by weight or more, 68 parts by weight or more, 70 parts by weight or more, or 72 parts by weight or more, and further, it may contain 84 parts by weight or less, 83 parts by weight or less, 82 parts by weight or less, 81 parts by weight or less, 80 parts by weight or less, or 79 parts by weight or less.

[0083]

[0084] According to one embodiment of the present invention, the vinyl cyan monomer for forming the vinyl cyan monomer unit included in the crosslinked copolymer may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, and derivatives thereof, and a specific example thereof may be acrylonitrile.

[0085] According to one embodiment of the present invention, the crosslinked copolymer may contain 15 parts by weight or more and 40 parts by weight or less of the vinyl cyan monomer unit, based on 100 parts by weight of the total of the aromatic vinyl monomer unit and the vinyl cyan monomer unit, and as a more specific example, it may contain 16 parts by weight or more, 17 parts by weight or more, 18 parts by weight or more, 19 parts by weight or more, 20 parts by weight or more, or 21 parts by weight or more, and further, it may contain 38 parts by weight or less, 36 parts by weight or less, 34 parts by weight or less, 32 parts by weight or less, 30 parts by weight or less, or 28 parts by weight or less.

[0086]

[0087] According to one embodiment of the present invention, the crosslinked copolymer has a particle size (D) when the cumulative percentage based on weight on the particle size distribution reaches 50%. 50) may be 30 ㎛ or more and 60 ㎛ or less. In the present invention, D 50 It means the particle size when the cumulative percentage based on weight on the particle size distribution reaches 50%, and it means the particle size when the cumulative weight from the sample with the smallest particle size on the particle size distribution reaches 50%. In the present invention, D of the crosslinked copolymer 50 It can be measured using a laser diffraction measuring device, and as a specific example, it can be measured using a light diffraction particle size analyzer (manufacturer: Sympatec GmbH, product name: HELOS / KR).

[0088] According to one embodiment of the present invention, the crosslinked copolymer has a particle size (D) when the cumulative percentage based on weight on the particle size distribution reaches 50%. 50 ) may be 32 ㎛ or more, 34 ㎛ or more, 36 ㎛ or more, 38 ㎛ or more, or 40 ㎛ or more, and may also be 55 ㎛ or less, 50 ㎛ or less, 45 ㎛ or less, or 40 ㎛ or less. D of the crosslinked copolymer 50 When the above range is satisfied, low gloss and excellent surface properties can be realized in the resin composition. If the D of the crosslinked copolymer 50 If it is larger than the above range, when the crosslinked copolymer is dispersed in the matrix, the surface roughness caused by the crosslinked copolymer may increase, which may deteriorate the surface properties and light reflection coefficient of the resin composition. In addition, the D of the crosslinked copolymer 50 If it is smaller than the above range, the surface roughness of the crosslinked copolymer dispersed in the matrix becomes small, so that diffuse reflection does not occur efficiently, and the gloss of the resin composition may increase.

[0089]

[0090] The crosslinked copolymer according to one embodiment of the present invention may have an average HW ratio of 0.09 or more and 1 or less. In the present invention, the average HW ratio of the crosslinked copolymer refers to an average value of the HW ratio (a / b) of each crosslinked copolymer observed when the surface of the resin composition is observed with an optical microscope. The a is half the value of the shortest axis length of each crosslinked copolymer observed when observed with an optical microscope, and the b is the longest axis length of each crosslinked copolymer observed when observed with an optical microscope.

[0091] Specifically, the crosslinked copolymer can be observed as a plane in an optical microscope image. The plane of the crosslinked copolymer observed in the optical microscope image is referred to as a 'plane', and assuming that the density of the crosslinked copolymer is constant, when the center of gravity of the crosslinked copolymer is within the 'plane', the longest axis of the crosslinked copolymer means the longest distance from the straight lines passing through the center of gravity to the two points where it meets the surface of the plane, and the shortest axis of the crosslinked copolymer means the shortest distance from the straight lines passing through the center of gravity to the two points where it meets the surface of the plane.

[0092] The crosslinked copolymer according to one embodiment of the present invention may have an average HW ratio of 0.092 or more, 0.094 or more, 0.096 or more, 0.098 or more, or 0.1 or more, and may also be 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, or 0.3 or less. When the average HW ratio of the crosslinked copolymer satisfies the above range, low gloss and excellent surface properties can be implemented in the resin composition.

[0093]

[0094] According to one embodiment of the present invention, the resin composition has a gloss of 7.5 or less, preferably 7 or less, more preferably 6.5 or less, and even more preferably 6 or less. If the resin composition does not include a crosslinked copolymer, the gloss of the resin composition may exceed the above-described range.

[0095]

[0096] Furthermore, the resin composition according to one embodiment of the present invention comprises the crosslinked copolymer, thereby enabling the provision of a nonporous molded article with guaranteed surface uniformity. The coefficient of variation of light reflection is a numerical value that indicates the uniformity of the surface of the molded article and also reflects gloss, indicating whether diffuse reflection occurs equally anywhere on the surface of the molded article while maintaining a matte, uniform surface throughout.

[0097]

[0098] The above light reflection variation coefficient can be measured using Python in the following manner.

[0099] 1) Sample imaging: Using a DSLR camera (Canon 750D) and a 200 mm x 200 mm surface light (White LED, Collimated Backlight LTS-3PFT), the prepared sample is photographed and imaged at a distance of 40 cm from the camera and 100 cm from the sample and at an angle of 90°.

[0100] 2) Grayscale conversion of sample image: The sample image is converted to grayscale (0-255) using the Open CV library. At this time, a grayscale value is assigned to each pixel in the sample image, and this grayscale value is used as the luminance.

[0101] 3) Image reconstruction: The image is divided into grids of 200 ㎛ x 200 ㎛ in size, and the image is reconstructed by averaging the luminance values ​​(grayscale values) of the pixels within each grid. At this time, each grid has one averaged luminance value.

[0102] 4) Luminance correction: The target grid is designated as Zone 1, the 8 grids adjacent to Zone 1 as Zone 2, and the 16 grids adjacent to Zone 2 as Zone 3. After assigning zone-specific correction coefficients of 1 to Zone 1, -0.0625 to Zone 2, and -0.03125 to Zone 3, the corrected luminance value of the target grid is derived using the following mathematical expression 3.

[0103] [Equation 3]

[0104]

[0105] In the above mathematical expression 2, L is the luminosity of the grid to be measured, L1 is the luminosity of the grid in the first zone, L21, L22, L23, ..., L28 are the luminosities of each of the eight grids in the second zone, and L31, L32, L33, ..., L316 are the luminosities of each of the 16 grids in the third zone.

[0106] The above correction factor is intended to readjust the brightness in consideration of the visual suppression effect, and may be intended to minimize errors due to an optical illusion in which the brightness of the target grid may be evaluated differently depending on the brightness of the surrounding grids when observed with the naked eye. Specifically, since the judgment by human visual perception is more important when it comes to “matte” when commercialized, the value measured by the device should not only indicate matte, but also be perceived as actually visually matte, and accordingly, the above correction factor may be applied to the measured value so that the measured value derived through the device is at a level equivalent to the actual visual effect that takes the optical illusion into account.

[0107] 5) Derivation of average and standard deviation: The average and standard deviation are derived from the corrected luminosity values ​​of each grid, and the average value and standard deviation of the luminosity thus derived are used to derive the coefficient of variation of light reflection using the above mathematical formula 2.

[0108]

[0109] According to one embodiment of the present invention, the light reflection variation coefficient of the resin composition may be 1.35 or less, and for specific examples, may be 1.3 or less, 1.25 or less, or 1.2 or less. If the light reflection variation coefficient exceeds the above range, the surface appearance quality of the resin composition may deteriorate. If the light reflection variation coefficient exceeds the above range, it may mean that the surface is not uniform and thus diffuse reflection does not occur in any part of the surface.

[0110]

[0111] 2. Matrix copolymer

[0112] According to one embodiment of the present invention, the matrix copolymer can serve as a matrix in a resin composition and play a fundamental role in realizing excellent physical properties of a resin molded product.

[0113] According to one embodiment of the present invention, the resin composition may include a matrix copolymer. The matrix copolymer may include an aromatic vinyl monomer unit and a vinyl cyan monomer unit.

[0114] According to one embodiment of the present invention, the aromatic vinyl monomer for forming the aromatic vinyl monomer unit included in the matrix copolymer may be at least one selected from the group consisting of styrene, α-methylstyrene, α-ethylstyrene, p-methylstyrene, o-methylstyrene, ot-butylstyrene, bromostyrene, chlorostyrene, trichlorostyrene, and derivatives thereof, and a specific example thereof may be styrene.

[0115] According to one embodiment of the present invention, the vinyl cyan monomer for forming the vinyl cyan monomer unit included in the matrix copolymer may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, and derivatives thereof, and a specific example thereof may be acrylonitrile.

[0116] According to one embodiment of the present invention, the matrix copolymer may be included in an amount of 48 parts by weight or more and 63 parts by weight or less with respect to 100 parts by weight of the resin composition, and more specifically, it may be included in an amount of 49 parts by weight or more, 50 parts by weight or more, 51 parts by weight or more, 52 parts by weight or more, or 53 parts by weight or more, and further, it may be included in an amount of 62 parts by weight or less, 61 parts by weight or less, 60 parts by weight or less, 59 parts by weight or less, or 58 parts by weight or less.

[0117]

[0118] 3. Graft copolymer

[0119] According to one embodiment of the present invention, the graft copolymer can serve to provide excellent moldability and impact resistance to the resin composition.

[0120] According to one embodiment of the present invention, the graft copolymer may include a conjugated diene polymer, an aromatic vinyl monomer unit, and a vinyl cyan monomer unit, and specifically, may be a core-shell structured graft copolymer including a core including a conjugated diene monomer unit; and a shell surrounding the core and including an aromatic vinyl monomer unit and a vinyl cyan monomer unit.

[0121] According to one embodiment of the present invention, the conjugated diene monomer for forming the conjugated diene monomer unit included in the graft copolymer may be at least one selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene, and isoprene, and a specific example thereof may be 1,3-butadiene.

[0122] According to one embodiment of the present invention, the aromatic vinyl monomer for forming the aromatic vinyl monomer unit included in the graft copolymer may be at least one selected from the group consisting of styrene, α-methylstyrene, α-ethylstyrene, p-methylstyrene, o-methylstyrene, ot-butylstyrene, bromostyrene, chlorostyrene, trichlorostyrene, and derivatives thereof, and a specific example thereof may be styrene.

[0123] According to one embodiment of the present invention, the vinyl cyan monomer for forming the vinyl cyan monomer unit included in the graft copolymer may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, and derivatives thereof, and a specific example thereof may be acrylonitrile.

[0124] According to one embodiment of the present invention, the graft copolymer may include a core comprising a conjugated diene monomer unit in an amount of 30 wt% to 70 wt%; and a shell surrounding the core and comprising an aromatic vinyl monomer unit and a vinyl cyan monomer unit in an amount of 30 wt% to 70 wt%. In addition, the shell may include an aromatic vinyl monomer unit and a vinyl cyan monomer unit in a weight ratio of 7:3 to 8:2, in which case the impact resistance, mechanical properties, and moldability of the copolymer may be more excellent.

[0125] According to one embodiment of the present invention, the graft copolymer may be included in an amount of 12 parts by weight or more and 42 parts by weight or less with respect to 100 parts by weight of the resin composition, and more specifically, it may be included in an amount of 13 parts by weight or more, 14 parts by weight or more, 15 parts by weight or more, 16 parts by weight or more, or 17 parts by weight or more, and further, it may be included in an amount of 40 parts by weight or less, 38 parts by weight or less, 36 parts by weight or less, 34 parts by weight or less, or 32 parts by weight or less.

[0126]

[0127] 4. Other additives

[0128] The resin composition according to one embodiment of the present invention may further include, if necessary, one or more additives selected from the group consisting of impact modifiers, lubricants, heat stabilizers, anti-drop agents, antioxidants, light stabilizers, ultraviolet ray blockers, pigments, and inorganic fillers, and in this case, the additives may be used in an amount of 5.0 parts by weight or less, or 0.1 to 1.0 parts by weight, based on 100 parts by weight of the copolymer and the thermoplastic resin.

[0129] In addition, the specific material of the additive may be used without particular limitation as long as it is used in a thermoplastic resin composition, but for example, the anti-dripping agent may be at least one selected from the group consisting of Teflon, polyamide, polysilicon, PTFE (polytetrafluoroethylene), and TFE-HFP (tetrafluoroethylene-hexafluoropropylene) copolymer in terms of further improving flame retardancy, and the inorganic filler may be at least one selected from the group consisting of barium sulfate, barium glass filler, and barium oxide.

[0130]

[0131] <Method for producing resin composition>

[0132] The present invention provides a method for producing the above resin composition.

[0133] The method for producing a resin composition according to the present invention is characterized in that the particle size (D) when the cumulative percentage by weight on the particle size distribution reaches at least 50% 50 ) is 30 ㎛ or more and 60 ㎛ or less, and an average HW ratio satisfies the following mathematical formula 1, and a step (S1) of mixing the crosslinked copolymer prepared in step S1; a conjugated diene polymer; a graft copolymer comprising an aromatic vinyl monomer unit and a vinyl cyan monomer unit; and a matrix copolymer comprising an aromatic vinyl monomer unit and a vinyl cyan monomer unit, wherein step S1 includes: a step (S1-1) of initiating a polymerization reaction by introducing an aromatic vinyl monomer, a vinyl cyan monomer, and a polymerization initiator into a reactor, and a step (S1-2) of dividing and introducing a crosslinking functional compound into the reactor after step S1 and polymerizing the same.

[0134] [Mathematical Formula 1]

[0135] 0.09≤ Average HW ratio ≤1

[0136] In the above mathematical expression 1, the average HW ratio is the average value of the HW ratio (a / b) calculated for each crosslinked copolymer observed when the surface of the resin composition is observed with an optical microscope,

[0137] The above a is ½ the value of the shortest axis length of each cross-linked copolymer observed when observed with an optical microscope,

[0138] The above b is the longest axis length of each crosslinked copolymer observed when observed with an optical microscope.

[0139] Hereinafter, a method for manufacturing a resin composition according to one embodiment of the present invention will be described step by step.

[0140]

[0141] 1. Step of preparing a crosslinked copolymer (S1)

[0142] According to one embodiment of the present invention, the step (S1) is to determine the particle size (D) when the weight-based cumulative percentage on the particle size distribution reaches 50%. 50 ) is 30 ㎛ or more and 60 ㎛ or less, and the average HW ratio satisfies the above mathematical formula 1, the step of manufacturing a crosslinked copolymer, the step (S1-1) of initiating a polymerization reaction by introducing an aromatic vinyl monomer, a vinyl cyan monomer, and a polymerization initiator into a reactor; and the step (S1-2) of dividing and introducing a crosslinking functional compound into the reactor and polymerizing it after the step (S1-1).

[0143]

[0144] (1) Polymerization reaction initiation step (S1-1)

[0145] According to one embodiment of the present invention, the step (S1-1) is a step for initiating polymerization, and may be a step of introducing a reaction solution into a reactor and then raising the temperature of the reactor to a predetermined temperature. In the step (S1), if the internal temperature of the reactor rises above the predetermined temperature, polymerization proceeds in the presence of a polymerization initiator, and in the step (S1), the internal temperature of the reactor may be raised to about 60°C to 120°C, and preferably, to 70°C to 110°C.

[0146]

[0147] According to one embodiment of the present invention, the step (S1-1) may include introducing an aromatic vinyl monomer, a vinyl cyan monomer, and a polymerization initiator into the reactor.

[0148] According to one embodiment of the present invention, the aromatic vinyl monomer introduced in the step (S1-1) may be at least one selected from the group consisting of styrene, α-methylstyrene, α-ethylstyrene, p-methylstyrene, o-methylstyrene, ot-butylstyrene, bromostyrene, chlorostyrene, trichlorostyrene, and derivatives thereof, and a specific example thereof may be styrene.

[0149] The aromatic vinyl monomer may be added in an amount of 60 to 95 parts by weight, 64 to 90 parts by weight, 68 to 85 parts by weight, or 72 to 80 parts by weight, based on 100 parts by weight of the vinyl cyan monomer and the aromatic vinyl monomer added in the step (S1-1), and within this range, a copolymer can be obtained with a high polymerization conversion rate, and while maintaining the mechanical properties of the copolymer, it can be a key factor in implementing a matte finish, and has an excellent compatibility effect.

[0150] According to one embodiment of the present invention, the vinyl cyan monomer introduced in the step (S1-1) may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, and derivatives thereof, and a specific example thereof may be acrylonitrile.

[0151] In addition, according to one embodiment of the present invention, the vinyl cyan monomer may be introduced in an amount of 5 to 40 parts by weight, 10 to 36 parts by weight, 15 to 32 parts by weight, or 20 to 28 parts by weight, based on 100 parts by weight of the aromatic vinyl monomer and the vinyl cyan monomer introduced in the step (S1-1), and within this range, a copolymer can be obtained with a high polymerization conversion rate, and the copolymer has excellent compatibility while maintaining mechanical properties.

[0152]

[0153] According to one embodiment of the present invention, the method for producing the crosslinked copolymer may be carried out by a suspension polymerization method, and may further include one or more additives selected from the group consisting of a polymerization initiator, a dispersant, a dispersing aid, and a molecular weight regulator as a solvent for carrying out polymerization in the step (S1-1), and may be carried out in the presence of these.

[0154] According to one embodiment of the present invention, the polymerization initiator is not particularly limited as long as it does not adversely affect the polymerization and is used to easily initiate the polymerization, and for example, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, di(t-butylperoxy-isopropyl)benzene, t-butyl cumyl peroxide, di-(t-amyl)-peroxide, dicumyl peroxide, butyl 4,4-di(t-butylperoxy)valerate, t-butylperoxybenzoate, 2,2-di(t-butylperoxy)butane, t-amyl peroxy-benzoate, t-butylperoxy-acetate, t-butylperoxy-(2-ethylhexyl)carbonate, t-butylperoxy isopropyl carbonate, t-butyl peroxy-3,5,5-trimethyl-hexanoate, It may be at least one selected from the group consisting of 1,1-di(t-butylperoxy)cyclohexane, t-amyl peroxyacetate, t-amylperoxy-(2-ethylhexyl)carbonate, 1,1-di(t-butylperoxy)-3,5,5-trimethylcyclohexane, 1,1-di(t-amylperoxy)cyclohexane, t-butyl-monoperoxy-maleate, 1,1'-azodi(hexahydrobenzonitrile), 1,1'-azobis(cyclohexane-1-cyclonitrile) and azobisisobutyronitrile, and specifically, one selected from the group consisting of dicumyl peroxide, 1,1-di(t-butyl peroxy)cyclohexane, 1,1'-azobis(cyclohexanecarbonitrile) and azobisisobutyronitrile. It could be strange.

[0155] In addition, the polymerization initiator may be used in an amount of 0.001 to 0.5 parts by weight, specifically 0.003 to 0.45 parts by weight or 0.06 to 0.3 parts by weight, based on 100 parts by weight of the aromatic vinyl monomer and the vinyl cyan monomer introduced in the step (S1-1). When used in the above range, the polymerization reaction can be performed more easily, thereby increasing the polymerization conversion rate.

[0156] According to one embodiment of the present invention, the dispersant may be at least one selected from the group consisting of water-soluble polyvinyl alcohol, partially saponified polyvinyl alcohol, polyacrylic acid, a copolymer of vinyl acetate and maleic anhydride, hydroxypropyl methylcellulose, gelatin, calcium phosphate, tricalcium phosphate, hydroxyapatite, sorbitan monolaurate, sorbitan trioleate, polyoxyethylene, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, and sodium dioctylsulfosuccinate, and a specific example thereof may be tricalcium phosphate.

[0157] According to one embodiment of the present invention, the dispersant may be used in an amount of 1.0 to 3.0 parts by weight, 1.5 to 2.5 parts by weight, or 1.5 to 2.0 parts by weight, based on 100 parts by weight of the aromatic vinyl monomer and the vinyl cyan monomer introduced in the step (S1-1), and within this range, the dispersion stability of the monomers in the polymerization system can be increased, thereby producing a copolymer having more uniform particles.

[0158] In addition, according to one embodiment of the present invention, the method for producing the crosslinked copolymer can be carried out by further including a dispersing aid during polymerization, and as a specific example, the dispersing aid can be a polyoxyethylene-based dispersing aid, and as a more specific example, it can be polyoxyethylene alkyl ether phosphate, and in this case, excellent polymerization stability is achieved.

[0159] According to one embodiment of the present invention, the molecular weight modifier may be at least one selected from the group consisting of, for example, α-methylstyrene dimer, t-dodecyl mercaptan, n-dodecyl mercaptan, octyl mercaptan, carbon tetrachloride, methylene chloride, methylene bromide, tetraethyl thiuram disulfide, dipentamethylene thiuram disulfide, and diisopropylxanthogen disulfide, and a specific example may be t-dodecyl mercaptan.

[0160] According to one embodiment of the present invention, the molecular weight regulator introduced in the step (S1-1) may be used in an amount of 0.01 to 0.40 parts by weight, 0.05 to 0.30 parts by weight, or 0.10 to 0.25 parts by weight, based on 100 parts by weight of the aromatic vinyl monomer and the vinyl cyan monomer introduced in the step (S1-1), and a copolymer having an appropriate weight average molecular weight can be prepared within this range.

[0161]

[0162] (2) Polymerization step (S1-2)

[0163] According to one embodiment of the present invention, the step (S1-2) is a step of dividing and introducing a crosslinking agent including the above-described crosslinking functional compound, and the crosslinking agent may be divided and introduced two or more times, or three or more times. In addition, the crosslinking functional compound may include at least one selected from the group consisting of acrylic compounds and aryl compounds, as described above, and may include a functional group such as a vinyl group or an acrylic group.

[0164]

[0165] If the crosslinking agent is added only at the early stage of polymerization, the crosslinking effect may be relatively low. Since the concentration of the crosslinking agent is high at the early stage of polymerization, the possibility of side reactions in which crosslinking agents bond with each other may increase. In addition, since the concentration of the crosslinking agent decreases toward the later stage of polymerization, it is difficult for the crosslinking moiety to be uniformly distributed within the copolymer chain, and the formation of the crosslinked copolymer may not be smooth, so the yield of the crosslinked copolymer may be significantly reduced. These problems ultimately lead to an increase in the gloss and the coefficient of variation of light reflection, and the non-uniformity may even lead to a decrease in the impact strength.

[0166] According to one embodiment of the present invention, the crosslinking functional compound is introduced in step (S1-2), and can be introduced starting immediately after step (S1-1), and can be introduced in two or more portions during polymerization, and preferably can be introduced in three or more portions.

[0167] According to one embodiment of the present invention, the time difference between the divided injections when the crosslinking functional compound is injected in step (S1-2) may be 1% to 30% of the total polymerization time. When the time difference between the divided injections is provided, the degree of crosslinking within the entire copolymer chain of the crosslinked copolymer can be achieved at a uniform and appropriate level, and the crosslinking density can also be excellent, which may play an important role in performing the function of imparting diffuse reflection to the surface of the resin molded product. In addition, the divided injection of the crosslinking agent may be performed for a time period of 20% to 70% of the total polymerization time, and it may be desirable to start and end the divided injection within this time range in order to impart a sufficient crosslinking effect.

[0168] According to one embodiment of the present invention, the crosslinking functional compound that is dividedly introduced during the polymerization in the step (S1-2) may be introduced in an amount of 0.05 to 0.30 parts by weight, preferably 0.05 to 0.20 parts by weight, and more preferably 0.05 to 0.15 parts by weight, based on 100 parts by weight of the aromatic vinyl monomer and the vinyl cyan monomer introduced in the step (S1-1).

[0169] In addition, according to one embodiment of the present invention, the crosslinking functional compound may be injected in the same or different amounts for each split injection, and it is preferable to control the amount so that the deviation between the amounts injected is not large.

[0170]

[0171] According to one embodiment of the present invention, in the step (S1-2), at least one of a molecular weight regulator and a polymerization initiator may be further added to the crosslinking agent and then divided and added.

[0172] In this way, when a molecular weight regulator and / or a polymerization initiator are included in the step (S1-2) and are dividedly introduced together with a crosslinking functional compound, control of the reactivity between monomers, the reactivity between the polymer chain and the crosslinking agent, etc. can be more easily achieved, and thus, control of the degree of crosslinking can be easily achieved, and accordingly, impact strength and heat resistance are maintained at excellent levels, and at the same time, a uniform and matte molded product can be obtained with a low coefficient of variation in gloss and light reflection.

[0173]

[0174] Meanwhile, according to one embodiment of the present invention, the polymerization in step (S1-2) may be performed at a temperature range of 50°C to 150°C, preferably 60°C to 130°C, and more preferably 65°C to 120°C. When polymerization is performed in the above-described temperature range, it may be preferable for obtaining the final polymerization conversion rate and other polymer properties.

[0175]

[0176] Meanwhile, the steps (S1-1) and (S1-2) according to one embodiment of the present invention may be performed under stirring. If the steps (S1-1) and (S1-2) according to one embodiment of the present invention are performed under stirring at 800 rpm or more, even if the crushing step (S1-3) described below is omitted, the particle size (D) when the cumulative percentage by weight of the crosslinked copolymer produced reaches 50% on the target particle size distribution 50 ) and can have an average HW ratio.

[0177]

[0178] (3) Crushing stage (S1-3)

[0179] According to one embodiment of the present invention, the step (S1) may further include a step (S1-3) of grinding the resultant product of the step (S1-2) when the steps (S1-1) and (S1-2) are performed without stirring or under stirring at less than 800 rpm. The step (S1-3) may further include a step (D) of grinding the resultant product of the step (S1-2) when the weight-based cumulative percentage of the crosslinked copolymer reaches 50% on the desired particle size distribution. 50 ) and may be a process for processing to have an average HW ratio.

[0180] According to one embodiment of the present invention, the step (S1-3) may be performed using one or more of an air jet mill, a rotary mill, a cutting mill, a ball mill, or a hammer mill.

[0181]

[0182] 2. Step of mixing crosslinked copolymer, matrix copolymer and graft copolymer (S2)

[0183] According to one embodiment of the present invention, the step (S2) may be to prepare a resin composition by mixing a crosslinked copolymer, a matrix copolymer, and a graft copolymer manufactured by the manufacturing method described above.

[0184]

[0185] According to one embodiment of the present invention, the matrix copolymer can generally be obtained by applying a commercially available resin, or by a commercially available method or a method of producing a crosslinked copolymer described above without using a crosslinking agent.

[0186]

[0187] According to one embodiment of the present invention, the graft copolymer can generally apply a commercially available resin and can be obtained through a commercially available method. For example, the graft copolymer can be manufactured by emulsion polymerizing a conjugated diene monomer to produce a rubbery polymer core (or seed), adding a vinyl cyanide monomer and an aromatic vinyl monomer to the core, and then emulsion graft polymerizing the core.

[0188]

[0189] <Molded product>

[0190] The present invention provides a molded article comprising the resin composition. For example, the molded article can be applied to various industrial fields such as various electrical and electronic products and automobile parts. As a molding method, general molding methods such as extrusion, injection, and casting can be applied. For example, in injection molding, compared to a product that aims to provide a matte molded article by corroding the surface of the mold, the molded article according to the present invention does not require corroding the surface of the mold, and even without post-processing the molded article, it is possible to provide a molded article having a matte and uniform surface in the injection-molded state.

[0191]

[0192] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0193]

[0194] Examples and Comparative Examples

[0195] The materials used in the examples and comparative examples are as follows.

[0196]

[0197] (1) Crosslinked copolymer: The crosslinked copolymers prepared in Manufacturing Examples 1 to 7 below were used.

[0198]

[0199] Manufacturing Example 1 - Crosslinked Copolymer A

[0200] To 100 parts by weight of a mixture consisting of 77 parts by weight of styrene monomer and 23 parts by weight of acrylonitrile, 0.2 parts by weight of azobisisobutyronitrile (AIBN), 0.3 parts by weight of t-dodecyl mercaptan (TDDM), and 2.0 parts by weight of tricalcium phosphate were added while stirring at 200 rpm, and after heating to 70°C, 0.2 parts by weight of t-dodecyl mercaptan (TDDM) and 0.1 parts by weight of allyl methacrylate as a crosslinking agent were added in three portions at one-hour intervals, while performing suspension polymerization for 5 hours. Thereafter, the resultant was washed and dehydrated, and dried at 85°C for 90 minutes in a fluidized bed dryer to prepare a crosslinked copolymer A in powder form.

[0201]

[0202] Manufacturing Example 2 - Crosslinked Copolymer B

[0203] Crosslinked copolymer A of the above manufacturing example 1 was pulverized to produce crosslinked copolymer B in powder form.

[0204]

[0205] Manufacturing Example 3 - Crosslinked Copolymer C

[0206] Crosslinked copolymer A of the above manufacturing example 1 was pulverized to produce crosslinked copolymer C in powder form.

[0207]

[0208] Manufacturing Example 4 - Crosslinked Copolymer D

[0209] A crosslinked copolymer was prepared in the same manner as in Manufacturing Example 1, except that 0.3 parts by weight of allyl methacrylate was added as a crosslinking agent in Manufacturing Example 1, and then the prepared crosslinked copolymer was pulverized to prepare a crosslinked copolymer D in powder form.

[0210]

[0211] Manufacturing Example 5 - Crosslinked Copolymer E

[0212] A crosslinked copolymer E in powder form was prepared in the same manner as in Manufacturing Example 1, except that stirring was performed at 600 rpm.

[0213]

[0214] Manufacturing Example 6 - Crosslinked Copolymer F

[0215] A crosslinked copolymer F in powder form was prepared in the same manner as in Manufacturing Example 1, except that stirring was performed at 1000 rpm.

[0216]

[0217] Manufacturing Example 7 - Crosslinked Copolymer G

[0218] A crosslinked copolymer G in powder form was prepared in the same manner as in Manufacturing Example 1, except that stirring was performed at 800 rpm.

[0219]

[0220] (2) Matrix copolymer: manufactured by LG Chemical, product name 97HC

[0221]

[0222] (3) Graft copolymer: manufactured by LG Chemical, product name DP270

[0223]

[0224] Experimental Example 1 - Measurement of the physical properties of crosslinked copolymers

[0225] * D 50 : D of the crosslinked copolymers manufactured in Manufacturing Examples 1 to 7 was measured using a light diffraction particle size analyzer (manufactured by Sympatec GmbH, product name: HELOS / KR). 50 The results were measured and recorded in Tables 1 and 2 below.

[0226] * HW ratio (a / b): The crosslinked copolymer, matrix copolymer, and graft copolymer manufactured in Manufacturing Examples 1 to 7 were added in the contents described in Tables 1 and 2 below, and 0.2 parts by weight of a heat stabilizer and 1 part by weight of a lubricant were added to 100 parts by weight of the total of the crosslinked copolymer, matrix copolymer, and graft copolymer to manufacture the resin compositions of Examples 1 to 7 and Comparative Examples 1 to 5.

[0227] The resin compositions manufactured in the above-described examples and comparative examples were put into an extrusion mixer (processing temperature: 220°C), extruded, and then injected to manufacture samples. When the surface of the manufactured samples was observed with an optical microscope (manufactured by Olympus, product name: OLS4000), the HW ratio (a / b) was calculated for each crosslinked copolymer observed in the optical microscope image by setting a as 1 / 2 of the shortest axis length and b as the length of the longest axis, and the average value of the HW ratio (a / b) calculated for each crosslinked copolymer is shown in Tables 1 and 2.

[0228]

[0229] Experimental Example 2 - Measurement of physical properties of resin compositions

[0230] The crosslinked copolymer, matrix copolymer and graft copolymer manufactured in Manufacturing Examples 1 to 7 were introduced in the contents described in Tables 1 and 2 below, and 0.2 parts by weight of a heat stabilizer and 1 part by weight of a lubricant were mixed with respect to 100 parts by weight of the total of the crosslinked copolymer, matrix copolymer and graft copolymer to manufacture the resin compositions of Examples 1 to 7 and Comparative Examples 1 to 5.

[0231] The resin compositions manufactured in the above-described examples and comparative examples were put into an extrusion mixer (processing temperature: 220°C), extruded, and then injected to manufacture samples. The properties of the resin compositions of the manufactured samples were measured using the following method, and are shown in Table 1 below.

[0232]

[0233] * Gloss: For a 0.4 mm thick sample, the surface gloss was measured at a 60° angle using a gloss meter according to the evaluation method specified in ASTM D523. In the present invention, if the gloss was 7.5 or less, the matte properties were evaluated as excellent.

[0234]

[0235] * Izod impact strength: Measured according to ASTM 256 for 1 / 4 inch thick samples. In the present invention, when the Izod impact strength is 18 kg·cm / cm or more, the impact resistance is evaluated as excellent.

[0236]

[0237] * Flow Index: Measured under 220℃ / 10kg conditions according to the evaluation method specified in ASTM D1238. In the present invention, a flow index of 10 g / 10 min or higher was evaluated as excellent.

[0238]

[0239] * Coefficient of Variation to Light Reflection: For a 0.4 mm thick sample, the measurement was made using Phyton using the following method.

[0240] 1) Sample imaging: Using a DSLR camera (Canon 750D) and a 200 mm x 200 mm sized surface light (White LED, Collimated Backlight LTS-3PFT), the prepared sample was photographed and imaged at a distance of 40 cm from the camera and sample, a distance of 100 cm from the sample and a 90° angle.

[0241] 2) Grayscale conversion of sample images: The sample images were converted to grayscale (0-255) using the Open CV library. At this time, a grayscale value was assigned to each pixel in the sample image, and this grayscale value was used as luminosity.

[0242] 3) Image reconstruction: The image was divided into grids of 200 ㎛ x 200 ㎛ in size, and the image was reconstructed by averaging the luminance values ​​(grayscale values) of the pixels within each grid. At this time, each grid has one averaged luminance value.

[0243] 4) Luminance correction: The target grid was designated as Zone 1, the 8 grids adjacent to Zone 1 as Zone 2, and the 16 grids adjacent to Zone 2 as Zone 3. After assigning zone-specific correction coefficients of 1 to Zone 1, -0.0625 to Zone 2, and -0.03125 to Zone 3, the corrected luminance value of the target grid was derived using the following mathematical expression 3.

[0244] [Equation 3]

[0245]

[0246] In the above mathematical expression 2, L is the corrected luminance value of the target grid, and L 1 is the luminosity of the first zone grid, L 2 1, L 2 2, L 2 3, ..., L 2 8 is the luminosity of each of the eight grids in Zone 2, L 3 1, L 3 2, L 3 3, ..., L 3 16 is the luminosity of each of the 16 grids in the third zone.

[0247] 5) Derivation of average and standard deviation: The average and standard deviation were derived from the corrected luminosity values ​​of each grid, and the average value and standard deviation of the luminosity thus obtained were used to derive the coefficient of variation of light reflection using the following mathematical formula 2.

[0248] [Equation 2]

[0249] C LR = D L / M L

[0250] C above LR is the coefficient of variation of light reflection, and D L is the standard deviation of luminosity, and M L is the average luminosity.

[0251]

[0252] * Surface appearance quality: The number of pinholes was measured within a sample with a unit area of ​​10 cm x 10 cm. If no pinholes were observed, it was evaluated as ○, if 1 to 7 pinholes were observed, it was evaluated as △, and if 8 or more were observed, it was evaluated as X.

[0253]

[0254] Example 1234567 Crosslinked copolymer type CDCFGDCD 50 (㎛)40404040604040Average HW ratio0.110.120.100.120.100.120.11Content (parts by weight)20203020202030Matrix copolymer (parts by weight)53534353536353Graft copolymer (parts by weight)27272727271717Gloss5655576Flow index (g / 10 min)4.14.32.84.34.45.13.8Impact strength (1 / 4``, kg·cm / cm)22191923211212Coefficient of variation of light reflection1.11.21.21.11.21.21.1Surface appearance quality○○○○○○○

[0255] Comparative Example 12345 Crosslinked Copolymer Type - ABEBD 50 (㎛) -250708070Average HW ratio -0.020.070.080.07Content (parts by weight) -20202030Matrix copolymer (parts by weight) 735353535353Graft copolymer (parts by weight) 2727272717Gloss 901391011Flow index (g / 10 min) 6.04.04.14.35.0Impact strength (1 / 4``, kg·cm / cm) 3021212212Coefficient of variation of light reflection 1.01.91.51.61.6Surface appearance quality○X△△△

[0256] Referring to Table 1, the desired range of D 50 It was confirmed that the resin compositions of Examples 1 to 7, which include a crosslinked copolymer satisfying an average HW ratio and have a light reflection variation coefficient of 1.35 or less, are all excellent in gloss, flow index, impact strength, and surface appearance quality.

[0257]

[0258] It was confirmed that Comparative Example 1, which does not include a crosslinked copolymer, had significantly higher gloss compared to Examples 1 to 7.

[0259]

[0260] D 50 Comparative Examples 2 to 5, which include a crosslinked copolymer exceeding 60 ㎛ and having an average HW ratio of 0.09 or less and a light reflection coefficient of variation exceeding 1.35, were confirmed to have a lower surface appearance quality and gloss compared to Examples 1 to 7.

Claims

1. A graft copolymer comprising a conjugated diene polymer, an aromatic vinyl monomer unit, and a vinyl cyan monomer unit; A matrix copolymer comprising an aromatic vinyl monomer unit and a vinyl cyan monomer unit; and A crosslinked copolymer comprising a crosslinking moiety formed from an aromatic vinyl monomer unit, a vinyl cyan monomer unit, and a crosslinking functional compound, The particle size (D) when the cumulative percentage based on weight in the particle size distribution diagram of the above crosslinked copolymer reaches 50% 50 ) is 30 ㎛ or more and 60 ㎛ or less, The average HW ratio of the above crosslinked copolymer satisfies the following mathematical formula 1, A resin composition having a light reflection variation coefficient of 1.35 or less, calculated by the following mathematical formula 2: [Mathematical Formula 1] 0.09≤ Average HW ratio ≤1 In the above mathematical expression 1, the average HW ratio is the average value of the HW ratio (a / b) calculated for each crosslinked copolymer observed when the surface of the resin composition is observed with an optical microscope, The above a is ½ the value of the shortest axis length of each cross-linked copolymer observed when observed with an optical microscope, The above b is the longest axis length of each crosslinked copolymer observed when observed with an optical microscope. [Equation 2] C LR = D L / M L In the above mathematical expression 2, C LR is the coefficient of variation of light reflection, and D L is the standard deviation of luminosity, and M L is the average luminosity.

2. In paragraph 1, The particle size (D) when the weight-based cumulative percentage of the above cross-linked copolymer reaches 50% 50 ) is a resin composition having a particle size of 30 ㎛ or more and 50 ㎛ or less.

3. In paragraph 1, A resin composition wherein the crosslinking functional compound forming the crosslinking portion of the above crosslinked copolymer is an acrylate compound or an allyl compound.

4. In paragraph 1, A resin composition wherein the crosslinking functional compound forming the crosslinking portion of the above crosslinked copolymer is allyl methacrylate.

5. In paragraph 1, A resin composition having a gloss of 7.5 or less at 60° as measured by a gloss meter according to the evaluation method of ASTM D523.

6. In paragraph 1, For 100 parts by weight of the total of the graft copolymer, the matrix copolymer and the crosslinked copolymer, Containing 10 parts by weight or more and 35 parts by weight or less of the above crosslinked copolymer, A resin composition comprising 48 parts by weight or more and 63 parts by weight or less of the above matrix copolymer.

7. Particle size (D) when the cumulative percentage based on weight on the particle size distribution chart reaches 50% 50 ) is 30 ㎛ or more and 60 ㎛ or less, and a step (S1) of manufacturing a crosslinked copolymer that satisfies the following mathematical formula 1, and A step (S2) of mixing a crosslinked copolymer manufactured in the above step S1; a conjugated diene polymer; a graft copolymer comprising an aromatic vinyl monomer unit and a vinyl cyan monomer unit; and a matrix copolymer comprising an aromatic vinyl monomer unit and a vinyl cyan monomer unit, The above S1 step: A step (S1-1) of initiating a polymerization reaction by introducing an aromatic vinyl monomer, a vinyl cyan monomer, and a polymerization initiator into a reactor, and A method for producing a resin composition, comprising, after the above step S1-1, a step (S1-2) of dividing and polymerizing a crosslinking functional compound into the reactor. [Mathematical Formula 1] 0.09≤ Average HW ratio ≤1 In the above mathematical expression 1, the average HW ratio is the average value of the HW ratio (a / b) calculated for each crosslinked copolymer observed when the surface of the resin composition is observed with an optical microscope, The above a is ½ the value of the shortest axis length of each cross-linked copolymer observed when observed with an optical microscope, The above b is the longest axis length of each crosslinked copolymer observed when observed with an optical microscope.

8. In paragraph 7, A method for producing a resin composition, wherein the step S1 further includes a step (S1-3) of crushing the resultant product of the step S1-2.

Images