Patent Application
20240309198
This application claims priority to Korean Patent Application No. 10-2021-0141872, filed Oct. 22, 2021, and Korean Patent Application No. 10-2022-0104724, re-filed on Aug. 22, 2022, based on the priority of the above patent, in the Korean Intellectual Property Office, the disclosures of each of which are incorporated herein by reference.
The present invention relates to a thermoplastic resin composition, a method of preparing the same, and a molded article manufactured using the same. More particularly, the present invention relates to a thermoplastic resin composition having excellent transparency, gloss, heat resistance, weather resistance, and impact resistance prepared by adjusting the composition and composition ratio of each layer of a graft copolymer having a structure consisting of a polymer seed, a rubber core surrounding the seed, and a graft shell surrounding the core, adjusting the morphology of the rubber core, and adjusting the refractive index difference with a matrix polymer; a method of preparing the thermoplastic resin composition; and a molded article manufactured using the thermoplastic resin composition.
Acrylate-styrene-acrylonitrile graft copolymers (hereinafter referred to as “ASA resins”) do not contain an unstable double bond, and thus have very excellent weather resistance. Accordingly, ASA resins are widely used in various fields such as electric/electronic parts, building materials (e.g., vinyl siding, etc.), extrusion profiles, and automobile parts. In recent years, in the field of outdoor products, market demand for high value-added products having properties such as unpainted, transparent, high chroma, and special color is continuously increasing.
To impart transparency to a graft copolymer including a rubber core, the refractive indexes of the rubber core, a graft shell, and a matrix resin should be similar to each other. In addition, in a resin composition including a graft copolymer and a matrix resin, when the difference in refractive index between a rubber core and the matrix resin is small, refraction and reflection of light do not occur at the interface of the graft copolymer, so that the resin composition becomes transparent.
In the case of an ASA resin including a butyl acrylate rubber core and a styrene-acrylonitrile copolymer shell, the refractive index of the butyl acrylate rubber is 1.46, and the refractive index of the styrene-acrylonitrile copolymer is 1.56 to 1.58. Due to the large difference in refractive index between the core and the shell, the resin is opaque. In addition, when an ASA resin is prepared using a styrene-acrylonitrile copolymer (hereinafter referred to as “SAN resin”) as a matrix resin, due to the large difference in refractive index between the SAN resin (refractive index: 1.56 to 1.58) and the core of the ASA resin, the resin composition is opaque.
Therefore, it is necessary to develop a resin composition having excellent heat resistance, weather resistance, and mechanical properties while realizing transparency and gloss by reducing the difference between the refractive index of each of a seed, a core, and a shell constituting an ASA resin and the refractive index of a matrix resin.
Therefore, the present invention has been made in view of the above problems, and it is one object of the present invention to provide a thermoplastic resin composition having excellent transparency, gloss, heat resistance, weather resistance, and impact resistance, a method of preparing the same, and a molded article manufactured using the same.
The above and other objects can be accomplished by the present invention described below.
In accordance with one aspect of the present invention, provided is a thermoplastic resin composition including an alkyl (meth)acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A) including a polymer seed including 51 to 77% by weight of an alkyl (meth)acrylate and 23 to 49% by weight of an aromatic vinyl compound, a rubber core surrounding the polymer seed and including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound, and a graft shell surrounding the rubber core and including 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl acrylate; and a non-graft copolymer (B) including an alkyl (meth)acrylate, an alkyl-substituted styrene-based compound, and a vinyl cyanide compound, wherein the graft copolymer (A) satisfies both Equations 1 and 2 below:
wherein r1 represents an average radius (nm) from a center of the graft copolymer to the polymer seed, and r2 represents an average radius (nm) from the center of the graft copolymer to the rubber core.
In the graft copolymer (A), a difference between a refractive index of the rubber core and a refractive index (μD25) of the graft shell may be preferably 0.08 to 0.09.
A difference between a refractive index of the polymer seed of the graft copolymer (A) and a refractive index (μD25) of the non-graft copolymer (B) may be preferably 0.01 or less.
Based on 100% by weight in total of the graft copolymer (A), the graft copolymer (A) may include preferably 5 to 35% by weight of the polymer seed, 25 to 55% by weight of the rubber core, and 25 to 55% by weight of the graft shell.
The non-graft copolymer (B) may include preferably 30 to 60% by weight of an alkyl (meth)acrylate, 25 to 55% by weight of an alkyl-substituted styrene-based compound, and 5 to 35% by weight of a vinyl cyanide compound.
The alkyl-substituted styrene-based compound may include preferably one or more selected from the group consisting of α-methyl styrene, p-methyl styrene, o-ethyl styrene, m-ethyl styrene, ρ-ethyl styrene, ρ-t-butyl styrene, and 2,4-dimethyl styrene.
The thermoplastic resin composition may include preferably 10 to 90% by weight of the graft copolymer (A) and 10 to 90% by weight of the non-graft copolymer (B).
The thermoplastic resin composition may include preferably an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (C) containing a rubber core having an average particle diameter of 50 to 150 nm.
When acetone is added to the thermoplastic resin composition, stirring and centrifugation are performed to obtain an insoluble sol and a soluble gel, and then refractive indexes thereof are measured, a difference between a refractive index of the sol and a refractive index (μD25) of the gel may be preferably 0.005 or less.
The thermoplastic resin composition may have a haze of preferably 6.5% or less as measured using an injection specimen having a thickness of 3 mm according to ASTM D1003.
The thermoplastic resin composition may have a gloss of preferably 110 or more as measured at 45° using an injection specimen having a thickness of 3 mm according to ASTM D2457.
The thermoplastic resin composition may have an Izod impact strength of preferably 14.5 kgf·cm/cm or more as measured at room temperature using a specimen having a thickness of ¼″ according to ASTM D256.
In accordance with another aspect of the present invention, provided is a method of preparing a thermoplastic resin composition, the method including kneading and extruding, at 180 to 300° C. and 80 to 400 rpm, an alkyl (meth)acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A) including a polymer seed including 51 to 77% by weight of an alkyl (meth)acrylate and 23 to 49% by weight of an aromatic vinyl compound, a rubber core surrounding the polymer seed and including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound, and a graft shell surrounding the rubber core and including 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl acrylate; and a non-graft copolymer (B) including an alkyl (meth)acrylate, an alkyl-substituted styrene-based compound, and a vinyl cyanide compound, wherein the graft copolymer (A) satisfies both Equations 1 and 2 below:
wherein r1 represents an average radius (nm) from a center of the graft copolymer to the seed, and r2 represents an average radius (nm) from the center of the graft copolymer to the core.
In the kneading and extruding, an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (C) containing a rubber core having an average particle diameter of 50 to 150 nm may be preferably included.
In accordance with yet another aspect of the present invention, provided is a molded article including the thermoplastic resin composition.
According to the present invention, the present invention has an effect of providing a thermoplastic resin composition having excellent transparency, gloss, heat resistance, weather resistance, and impact resistance, a method of preparing the same, and a molded article manufactured using the same.
In addition, the thermoplastic resin composition of the present invention can be applied to automotive interior materials, automotive exterior materials, building materials, home appliances, or medical parts that require excellent transparency, gloss, heat resistance, weather resistance, and impact resistance. In this case, an aesthetically excellent appearance and excellent impact resistance can be realized.
Hereinafter, a thermoplastic resin composition, a method of preparing the same, and a molded article manufactured using the same according to the present invention will be described in detail.
The present inventors have studied to develop a thermoplastic resin composition including an ASA resin and a matrix resin and having excellent transparency, gloss, heat resistance, weather resistance, and impact resistance. During the study, the present inventors confirmed that, when the composition, composition ratio, and refractive index difference of a seed, a core, and a shell constituting the ASA resin were adjusted within a predetermined range, and a refractive index difference with the matrix resin was reduced, impact resistance was secured, transparency and gloss were greatly improved, and heat resistance and weather resistance were excellent. Based on these results, the present inventors conducted further studies to complete the present invention.
The thermoplastic resin composition of the present invention includes an alkyl (meth)acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A) including a polymer seed including 51 to 77% by weight of an alkyl (meth)acrylate and 23 to 49% by weight of an aromatic vinyl compound, a rubber core surrounding the polymer seed and including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound, and a graft shell surrounding the rubber core and including 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl acrylate; and a non-graft copolymer (B) including an alkyl (meth)acrylate, an alkyl-substituted styrene-based compound, and a vinyl cyanide compound, wherein the graft copolymer (A) satisfies both Equations 1 and 2 below. In this case, transparency, gloss, heat resistance, weather resistance, and impact resistance may be excellent.
In Equations 1 and 2, r1 represents an average radius (nm) from the center of the graft copolymer to the polymer seed, and r2 represents an average radius (nm) from the center of the graft copolymer to the core.
Hereinafter, each component of the thermoplastic resin composition of the present invention will be described in detail.
(A) Alkyl (meth)acrylate-aromatic Vinyl Compound-Vinyl Cyanide Compound Graft Copolymer
For example, the graft copolymer (A) may include a polymer seed including 51 to 77% by weight of an alkyl (meth)acrylate and 23 to 49% by weight of an aromatic vinyl compound, a rubber core surrounding the polymer seed and including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound, and a graft shell surrounding the rubber core and including 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl acrylate. In this case, transparency, gloss, weather resistance, and impact resistance may be excellent, and compatibility with the non-graft copolymer (B) may be excellent due to the alkyl acrylate contained in the graft shell.
For example, the polymer seed of the graft copolymer (A) may be prepared by polymerizing 51 to 77% by weight of an alkyl (meth)acrylate and 23 to 49% by weight of an aromatic vinyl compound, preferably 52 to 70% by weight of an alkyl (meth)acrylate and 30 to 48% by weight of an aromatic vinyl compound, more preferably 52 to 65% by weight of an alkyl (meth)acrylate and 35 to 48% by weight of an aromatic vinyl compound. In this case, the refractive index difference between the non-graft copolymer (B) and the seed may be reduced, and thus transparency, gloss, heat resistance, and weather resistance may be excellent.
For example, the polymer seed of the graft copolymer (A) may have an average particle diameter of 120 to 220 nm, preferably 150 to 190 nm. Within this range, impact resistance, fluidity, and transparency may be imparted to a finally prepared thermoplastic resin composition.
In the present disclosure, the average particle diameters of the polymer seed, rubber core, and graft shell of the graft copolymer may be measured by a measurement method commonly used in the art to which the present invention pertains using electron microscopy such as SEM and TEM, without particular limitation. For example, for each of the polymer seed, the rubber core, and the graft shell, upon completion of preparation thereof, a sample is obtained, and the average particle diameter of the sample is measured by dynamic light scattering. Specifically, the average particle diameter may be measured as an intensity value using a Nicomp 380 particle size analyzer (manufacturer: PSS) in a Gaussian mode. As a specific measurement example, a sample is prepared by diluting 0.1 g of latex (TSC: 35 to 50 wt %) 1,000 to 5,000-fold with distilled water, i.e., a sample is diluted appropriately so as not to deviate significantly from an intensity setpoint of 300 kHz, and is placed in a glass tube. Then, the average particle diameter of the sample is measured using a flow cell in auto-dilution in a measurement mode of dynamic light scattering/intensity 300 kHz/intensity-weight Gaussian analysis. At this time, setting values are as follows: temperature: 23° C. and measurement wavelength: 632.8 nm.
For example, the difference between the refractive index of the polymer seed of the graft copolymer (A) and the refractive index (μD25) of the non-graft copolymer (B) may be 0.01 or less, preferably 0.007 or less, more preferably 0.005 or less, still more preferably 0.004 or less. Within this range, transparency and gloss may be realized, and impact resistance may be excellent.
For example, the rubber core of the graft copolymer (A) may surround the polymer seed and may be prepared by polymerizing 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound, preferably 80 to 90% by weight of an alkyl acrylate and 10 to 20% by weight of an aromatic vinyl compound, more preferably 82 to 88% by weight of an alkyl acrylate and 12 to 18% by weight of an aromatic vinyl compound. In this case, physical property balance, impact resistance, transparency, gloss, and weather resistance may be excellent.
For example, the rubber core may have an average particle diameter of 200 to 300 nm, preferably 220 to 280 nm, more preferably 230 to 260 nm. Within this range, physical property balance and impact resistance may be excellent.
For example, the graft shell of the graft copolymer (A) may surround the rubber core and may be prepared by polymerizing 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl acrylate, preferably 67 to 77% by weight of an aromatic vinyl compound, 14 to 22% by weight of a vinyl cyanide compound, and 5 to 12% by weight of an alkyl acrylate, more preferably 70 to 75% by weight of an aromatic vinyl compound, 17 to 22% by weight of a vinyl cyanide compound, and 5 to 10% by weight of an alkyl acrylate. In this case, due to the alkyl acrylate contained in the graft shell, compatibility with the non-graft copolymer (B) may be excellent, and thus physical property balance, transparency, gloss, impact resistance, and weather resistance may be excellent.
For example, the difference between the refractive index of the rubber core of the graft copolymer (A) and the refractive index (μD25) of the graft shell may be 0.08 to 0.09, preferably 0.081 to 0.089, more preferably 0.083 to 0.089, still more preferably 0.084 to 0.088. Within this range, transparency, gloss, heat resistance, weather resistance, and impact resistance may be excellent.
In the present disclosure, for example, the aromatic vinyl compound may include one or more selected from the group consisting of styrene, α-methyl styrene, o-methyl styrene, ρ-methyl styrene, m-methyl styrene, ethyl styrene, isobutyl styrene, t-butyl styrene, o-bromostyrene, ρ-bromostyrene, m-bromostyrene, o-chlorostyrene, ρ-chlorostyrene, m-chlorostyrene, vinyltoluene, vinylxylene, fluorostyrene, and vinylnaphthalene, preferably styrene.
In the present disclosure, for example, the vinyl cyanide compound may include one or more selected from the group consisting of acrylonitrile, methacrylonitrile, ethylacrylonitrile, and isopropylacrylonitrile, preferably acrylonitrile.
In the present disclosure, the alkyl (meth)acrylate may be defined to include both an alkyl acrylate and an alkyl methacrylate.
In the present disclosure, for example, the alkyl acrylate may be an alkyl acrylate containing an alkyl group having 1 to 15 carbon atoms or may include preferably one or more selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylbutyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, hexyl acrylate, heptyl acrylate, n-pentyl acrylate, and lauryl acrylate, more preferably an alkyl acrylate containing an alkyl group having 1 to 4 carbon atoms, still more preferably n-butylacrylate, 2-ethylhexyl acrylate, or a mixture thereof.
In the present disclosure, for example, the alkyl methacrylate may be an alkyl methacrylate containing an alkyl group having 1 to 15 carbon atoms or may include preferably one or more selected from the group consisting of methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylbutyl methacrylate, 2-ethylhexyl methacrylate, and lauryl methacrylate, more preferably an alkyl methacrylate containing an alkyl group having 1 to 4 carbon atoms, still more preferably methyl methacrylate.
For example, the graft copolymer (A) satisfies both Equations 1 and 2 below. In this case, since the thickness of the rubber core of the graft copolymer (A) having a large difference in refractive index with the non-graft copolymer (B) is reduced, transparency and gloss may be improved, and impact resistance may be excellent.
In Equations 1 and 2, r1 represents an average radius (nm) from the center of the graft copolymer to the polymer seed, and r2 represents an average radius (nm) from the center of the graft copolymer to the core.
r1 may be a value obtained by dividing the average particle diameter of the seed by 2, and r2 may be a value obtained by dividing the average particle diameter of the seed-containing core by 2.
r2-r1 means the thickness of the rubber core. As the thickness of the rubber core decreases, the transmittance of light increases, thereby improving transparency and gloss.
Equation 1 may be preferably 220≤2*r≤280, more preferably 230≤2*r2≤260. Within this range, impact resistance may be excellent.
Equation 2 may be preferably 30≤r2−r1≤40, more preferably 32≤r2−r1≤37. Within this range, transparency and gloss may be excellent.
In the present disclosure, the refractive index of each of the polymer seed, rubber core, and graft shell of the graft copolymer and the refractive index of the non-graft copolymer (B) may be calculated by Equation 3 below.
Wti=Weight fraction (%) of each component of copolymer
RIi=Refractive index of polymer of each component of copolymer
In the present disclosure, the refractive index of each component of the copolymer, i.e., the refractive index of the polymer of a monomer, may be a value generally known in the art to which the present invention pertains. For example, methyl methacrylate may have a refractive index of 1.49, butyl acrylate may have a refractive index of 1.46, styrene may have a refractive index of 1.592, and acrylonitrile may have a refractive index of 1.52.
For example, the graft copolymer (A) may have a gel content of 70 to 98% by weight, preferably 80 to 95% by weight, more preferably 82 to 92% by weight. Within this range, mechanical properties such as impact resistance may be excellent.
For example, the graft copolymer (A) may have a swelling index of 2.5 to 10, preferably 3 to 6, more preferably 3.5 to 5. Within this range, mechanical properties, such as impact resistance, and weather resistance may be excellent.
For example, the graft copolymer (A) may have a grafting degree of 30% or more, preferably 35 to 70%, more preferably 35 to 60%. Within this range, mechanical properties, such as impact resistance, and weather resistance may be excellent.
In the present disclosure, when measuring gel content, swelling index, and grafting degree, 30 g of acetone is added to 0.5 g of a powdered graft copolymer, agitation is performed at 210 rpm and room temperature for 12 hours using a shaker (SKC-6075, Lab Companion Co.), centrifugation is performed at 18,000 rpm and 0° C. for 3 hours using a centrifuge (Supra R30, Hanil Science Co.) to separate only insoluble matter that is not dissolved in acetone, and the separated insoluble matter is dried via forced circulation at 85° C. for 12 hours using an oven (OF-12GW, Lab Companion Co.). Then, the weight of the dried insoluble matter is measured, and gel content, swelling index, and grafting degree are calculated by Equations 4, 5, and 6 below.
In Equation 6, the weight (g) of grafted monomers is obtained by subtracting rubber weight (g) from the weight (g) of insoluble matter (gel) obtained by dissolving a graft copolymer in acetone and performing centrifugation, and the rubber weight (g) is the weight (g) of rubber components theoretically added to graft copolymer powder.
For example, based on 100% by weight in total of the graft copolymer (A), the graft copolymer (A) may include the polymer seed in an amount of 5 to 35% by weight, preferably 10 to 30% by weight, more preferably 15 to 25% by weight. Within this range, impact resistance and physical property balance may be excellent. When the content of the polymer seed is less than the range, transparency, gloss, and weather resistance may be reduced. When the content of the polymer seed exceeds the range, impact resistance may be reduced.
For example, based on 100% by weight in total of the graft copolymer (A), the graft copolymer (A) may include the rubber core in an amount of 25 to 55% by weight, preferably 30 to 50% by weight, more preferably 35 to 45% by weight. Within this range, impact resistance and physical property balance may be excellent. When the content of the rubber core is less than the range, the impact absorbing effect of the graft copolymer may be reduced due to insufficient rubber content. When the content of the rubber core exceeds the range, due to insufficient graft shell content, rubber may agglomerate during coagulation. In addition, the compatibility with the non-graft copolymer (B) may be significantly reduced. As a result, the impact absorbing effect of the graft copolymer may be reduced, and a desired level of refractive index may not be obtained.
For example, based on 100% by weight in total of the graft copolymer (A), the graft copolymer (A) may include the graft shell in an amount of 25 to 55% by weight, preferably 30 to 50% by weight, more preferably 35 to 45% by weight. Within this range, impact resistance and physical property balance may be excellent. When the content of the graft shell is less than the range, due to low grafting efficiency, rubber may agglomerate, which reduces the compatibility with the non-graft copolymer (B) and reduces the impact absorbing effect of the graft copolymer. When an excess of the graft shell is included, due to a decrease in the relative content of rubber, impact resistance may be reduced.
For example, the rubber core may be an acrylic rubber prepared by polymerizing an alkyl acrylate, an aromatic vinyl compound, and a crosslinking agent. When the crosslinking agent is included, a gel content may be adjusted, and impact resistance may be excellent.
For example, the polymer seed, the rubber core, or both may include one or more selected from the group consisting of divinylbenzene, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, aryl acrylate, aryl methacrylate, trimethylolpropane triacrylate, tetraethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, triaryl isocyanurate, triarylamine, diallylamine, and a compound represented by Chemical Formula 1 below as the crosslinking agent.
In Chemical Formula 1, A is independently a substituent having a vinyl group, or a (meth)acrylate group, A′ is a hydrogen group, a substituent having a vinyl group, an alkyl group having 1 to 30 carbon atoms, an allylalkyl group having 5 to 24 carbon atoms, an arylamine group having 5 to 24 carbon atoms, or an allyl group having 6 to 30 carbon atoms, R is independently a divalent ethyl group or a propyl group, and n is an integer of 0 to 15, preferably 0 to 5, more preferably 0 to 4.
For example, based on 100 parts by weight in total of monomers used in the preparation of each of the polymer seed, rubber core, and graft shell of the graft copolymer (A), the crosslinking agent may be used in an amount of 0.001 to 3 parts by weight, preferably 0.05 to 1 part by weight for each preparation.
In the present disclosure, the content of a monomer in a polymer may mean a content (% by weight) of the monomer fed when the polymer is prepared, or may mean a value (% by weight) calculated by converting a unit in the polymer into the monomer.
For example, a method of preparing the graft copolymer (A) may include step (i) of preparing a polymer seed by including 51 to 77% by weight of an alkyl (meth)acrylate and 23 to 49% by weight of an aromatic vinyl compound; step (ii) of preparing a rubber core by including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound in the presence of the polymer seed; and step (iii) of preparing a graft copolymer by graft-polymerizing 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl acrylate in the presence of the rubber core. In this case, transparency, gloss, weather resistance, and impact resistance may be excellent.
The method of preparing the graft copolymer (A) may preferably include step (i) of preparing a polymer seed by including 51 to 77% by weight of an alkyl (meth)acrylate, 23 to 49% by weight of an aromatic vinyl compound, an electrolyte, a crosslinking agent, an initiator, and an emulsifier; step (ii) of preparing a rubber core by including 78 to 90% by weight of an alkyl acrylate, 10 to 22% by weight of an aromatic vinyl compound, a crosslinking agent, an initiator, and an emulsifier in the presence of the polymer seed; and step (iii) of preparing a graft copolymer by graft-polymerizing 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, 3 to 15% by weight of an alkyl acrylate, a crosslinking agent, an initiator, and an emulsifier in the presence of the rubber core. In this case, transparency, gloss, weather resistance, and impact resistance may be excellent.
In steps (i), (ii), and (iii), emulsifiers commonly used in the art to which the present invention pertains may be used as the emulsifier without particular limitation. For example, one or more selected from the group consisting of an alkyl sulfosuccinate metal salt having 12 to 18 carbon atoms or a derivative thereof, an alkyl sulfuric acid ester having 12 to 20 carbon atoms or a derivative thereof, an alkyl sulfonic acid metal salt having 12 to 20 carbon atoms or a derivative thereof, fatty acid soap, and rosin acid soap may be used as the emulsifier.
The alkyl sulfosuccinate metal salt having 12 to 18 carbon atoms or the derivative thereof may include preferably one or more selected from the group consisting of dicyclohexyl sulfosuccinate, dihexyl sulfosuccinate, di-2-ethyl hexyl sulfosuccinate sodium salt, di-2-ethyl hexyl sulfosuccinate potassium salt, dioctyl sulfosuccinate sodium salt, and dioctyl sulfosuccinate potassium salt.
The alkyl sulfuric acid ester having 12 to 20 carbon atoms or the derivative thereof and the alkyl sulfonic acid metal salt having 12 to 20 carbon atoms or the derivative thereof may include preferably one or more selected from the group consisting of sodium lauryl sulfate, sodium dodecyl sulfate, sodium dodecyl benzene sulfate, sodium octadecyl sulfate, sodium oleic sulfate, potassium dodecyl sulfate, and potassium octadecyl sulfate.
The fatty acid soap may include preferably one or more selected from the group consisting of sodium or potassium salts of oleic acid, stearic acid, lauric acid, and mixed fatty acids.
The rosin acid soap may be preferably abietic acid salt.
For example, based on 100 parts by weight in total of monomers used in the preparation of each of the polymer seed, rubber core, and graft shell of the graft copolymer (A), the emulsifier may be used in an amount of 0.01 to 5 parts by weight, preferably 0.1 to 4 parts by weight, more preferably 1 to 3 parts by weight for each preparation.
In steps (i), (ii), and (iii), the type of the initiator is not particularly limited, but a radical initiator may be preferably used.
For example, the radical initiator may include one or more selected from the group consisting of inorganic peroxides, organic peroxides, peroxyketal-based peroxides, peroxycarbonate peroxides, and azo compounds.
The inorganic peroxides may include preferably one or more selected from the group consisting of sodium persulfate, potassium persulfate, ammonium persulfate, potassium superphosphate, and hydrogen peroxide.
The organic peroxides may include one or more selected from the group consisting of t-butyl peroxide, cumene hydroperoxide, p-menthane hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)-hexane, di-t-amyl peroxide, 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-butylperoxy)-cyclohexane, 1,1-di(t-amylperoxy)-cyclohexane, ethyl 3,3-di(t-amylperoxy)-butyrate, diisopropylbenzene mono-hydroperoxide, t-amyl hydroperoxide, t-butyl hydroperoxide, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, di-(3,3,5-trimethylhexanoyl)-peroxide, t-butylperoxy-2-ethylhexanoate, t-butylperoxy-3,3,5-trimethylhexanoyl, t-amyl peroxy neodecanoate, t-amyl peroxy pivalate, t-amyl peroxy-2-ethylhexanoate, t-butyl peroxyacetate, t-butyl peroxybenzoate, t-amyl peroxy 2-ethylhexyl carbonate, t-butyl peroxy 2-ethylhexyl carbonate, t-butyl peroxy isopropyl monocarbonate, t-butyl peroxy maleic acid, cumyl peroxyneodecanoate, 1,1,3,3,-tetramethylbutylperoxy neodecanoate, 1,1,3,3,-tetramethylbutylperoxy 2-ethylhexanoate, di-2-ethylhexyl peroxydicarbonate, 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, dibenzoyl peroxide, dilauroyl peroxide, 3,5,5-trimethylhexanol peroxide, and t-butylperoxy isobutyrate.
The peroxyketal-based peroxides may include preferably one or more selected from the group consisting of 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-butylperoxy)cyclohexane, 1,1-di(t-amylperoxy)cyclohexane, ethyl-3,3-di(t-butylperoxy)butyrate, and ethyl-3,3-di(t-amylperoxy)butyrate.
The peroxycarbonate peroxides may include preferably one or more selected from the group consisting of dialkyl peroxides such as dicumyl peroxide, di(t-butylperoxy)-m/p-diisopropylbenzene, 2,5-dimethyl-2,5-(t-butylperoxy)hexane, t-butylcumyl peroxide, and 2,5-methyl-2,5-(t-butylperoxy)hexyne-3, t-butylperoxy 2-ethylhexyl monocarbonate, and t-butyl peroxybenzoate.
The azo compounds may include preferably one or more selected from the group consisting of azobis isobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobis cyclohexanecarbonitrile, and azobis isobutyric acid methyl.
In at least one of steps (i), (ii), and (iii), to promote the initiation reaction for peroxides, an activator may be used, preferably in combination with the polymerization initiator.
Activators commonly used in the art to which the present invention pertains may be used as the activator of the present invention without particular limitation.
Based on 100 parts by weight in total of the graft copolymer, the activator may be included in an amount of 0.01 to 3 parts by weight, preferably 0.01 to 1 part by weight. Within this range, a high degree of polymerization may be realized.
For example, in steps (i), (ii), and (iii), an oxidation-reduction catalyst may be used in combination with the initiator to further promote initiation reaction.
For example, the oxidation-reduction catalyst may include one or more selected from the group consisting of sodium pyrophosphate, dextrose, ferrous sulfide, sodium sulfite, sodium formaldehyde sulfoxylate, and sodium ethylenediaminetetraacetate, preferably a mixture of sodium pyrophosphate, dextrose, and ferrous sulfide, without being limited thereto.
For example, in step (i), the electrolyte may include one or more selected from the group consisting of KCl, NaCl, KHCO3, NaHCO3, K2CO3, Na2CO3, KHSO3, NaHSO4, Na2S2O7, K3P2O7, K3PO4, Na3PO4, and Na2HPO4, without being limited thereto.
For example, in step (iii), a molecular weight modifier may be included.
For example, based on 100 parts by weight in total of the graft copolymer, the molecular weight modifier may be included in an amount of 0.01 to 2 parts by weight, preferably 0.05 to 2 parts by weight, more preferably 0.05 to 1 part by weight. Within this range, a polymer having a desired molecular weight may be easily prepared.
For example, the molecular weight modifier may include one or more selected from the group consisting of α-methyl styrene dimer, t-dodecyl mercaptan, n-dodecyl mercaptan, octyl mercaptan, carbon tetrachloride, methylene chloride, methylene bromide, tetra ethyl thiuram disulfide, dipentamethylene thiuram disulfide, and diisopropylxanthogen disulfide, without being limited thereto.
In the present disclosure, 100 parts by weight of the graft copolymer may mean the total weight of the finally obtained graft copolymer; the total weight of the monomers used in the preparation of the polymer seed, the rubber core, and the graft shell, considering that most of the added monomers are used for polymerization; or the total weight of the monomers added in the preparation of the polymer seed and the rubber core and the monomers added in the preparation of the graft shell.
For example, the graft copolymer (A) may be prepared by emulsion polymerization. In this case, chemical resistance, weather resistance, fluidity, tensile strength, and impact strength may be excellent.
The emulsion polymerization may be performed according to an emulsion graft polymerization method commonly practiced in the art to which the present invention pertains, without particular limitation.
Polymerization temperature during the emulsion polymerization is not particularly limited. For example, the emulsion polymerization may be performed at 50 to 85° C., preferably 60 to 80° C.
For example, latex of the graft copolymer (A) may be prepared in the form of powder through a conventional process including coagulation, washing, and drying. As a specific example, a metal salt or an acid is added, coagulation is performed at 60 to 100° C., and aging, dehydration, washing, and drying are performed to prepare the latex of the graft copolymer (A) in powder form, but the present invention is not limited thereto.
For example, based on the total weight of the graft copolymer (A) and the non-graft copolymer (B), the graft copolymer (A) may be included in an amount of 10 to 90% by weight, preferably 30 to 70% by weight, more preferably 40 to 60% by weight. Within this range, transparency, gloss, heat resistance, weather resistance, and impact resistance may be excellent.
(B) Non-Graft Copolymer Including alkyl (meth)acrylate, Alkyl-Substituted Styrene-Based Compound, and Vinyl Cyanide Compound
The non-graft copolymer (B) is a matrix resin, and may include an alkyl (meth)acrylate, an alkyl-substituted styrene-based compound, and a vinyl cyanide compound. In this case, compatibility with the graft copolymer (A) may be excellent, heat resistance may be secured, and transparency, gloss, weather resistance, and impact resistance may be excellent.
The non-graft copolymer (B) may include preferably 30 to 60% by weight of an alkyl (meth)acrylate, 25 to 55% by weight of an alkyl-substituted styrene-based compound, and 5 to 35% by weight of a vinyl cyanide compound, more preferably 35 to 55% by weight of an alkyl (meth)acrylate, 30 to 50% by weight of an alkyl-substituted styrene-based compound, and 15 to 25% by weight of a vinyl cyanide compound, still more preferably 40 to 47% by weight of an alkyl (meth)acrylate, 35 to 42% by weight of an alkyl-substituted styrene-based compound, and 17 to 23% by weight of a vinyl cyanide compound. Within this range, compatibility with the graft copolymer (A) may be excellent, heat resistance may be secured, and transparency, gloss, weather resistance, and impact resistance may be excellent.
In the present disclosure, the term “non-graft copolymer” refers to a copolymer obtained without graft polymerization, and more specifically refers to a copolymer without a graft bond in the presence of rubber.
In the present disclosure, for example, the alkyl-substituted styrene-based compound may include one or more selected from the group consisting of α-methyl styrene, ρ-methyl styrene, o-ethyl styrene, m-ethyl styrene, ρ-ethyl styrene, ρ-t-butyl styrene, and 2,4-dimethyl styrene, preferably α-methyl styrene. In this case, heat resistance may be excellent.
The types of the alkyl (meth)acrylate and the vinyl cyanide compound included in the non-graft copolymer (B) may be the same as the types of the alkyl (meth)acrylate and the vinyl cyanide compound included in the graft copolymer (A).
The non-graft copolymer (B) may be preferably a methyl methacrylate-α-methyl styrene-acrylonitrile copolymer. In this case, since the difference between the refractive index of the polymer seed of graft copolymer (A) and the refractive index of the non-graft copolymer (B) is reduced, transparency, gloss, and heat resistance may be excellent.
For example, the non-graft copolymer (B) may have a weight average molecular weight of 50,000 to 150,000 g/mol, preferably 70,000 to 130,000 g/mol, more preferably 90,000 g/mol to 120,000 g/mol. Within this range, impact resistance and moldability may be excellent.
In the present disclosure, unless otherwise defined, the weight average molecular weight may be measured using gel permeation chromatography (GPC, Waters Breeze). As a specific example, the weight average molecular weight may be measured using tetrahydrofuran (THF) as an eluate through gel permeation chromatography (GPC, Waters Breeze). In this case, weight average molecular weight is obtained as a relative value to a polystyrene (PS) standard sample. As a specific measurement example, the weight average molecular weight may be measured under conditions of solvent: THF, column temperature: 40° C., flow rate: 0.3 ml/min, sample concentration: 20 mg/ml, injection amount: 5 μl, column model: 1× PLgel 10 μm MiniMix-B (250×4.6 mm)+1× PLgel 10 μm MiniMix-B (250×4.6 mm)+1× PLgel 10 μm MiniMix-B Guard (50×4.6 mm), equipment name: Agilent 1200 series system, refractive index detector: Agilent G1362 RID, RI temperature: 35° C., data processing: Agilent ChemStation S/W, and test method (Mn, Mw and PDI): OECD TG 118.
For example, the non-graft copolymer (B) may have a glass transition temperature of 110° C. or higher, preferably 115° C. or higher, more preferably 115 to 150° C. as measured according to ASTM D3418. In this case, heat resistance may be improved.
In the present disclosure, glass transition temperature may be measured at a heating rate of 10° C./min using a TA Instruments Q100 differential scanning calorimeter (DSC) according to ASTM D3418.
For example, the non-graft copolymer (B) may have a melt flow index of 8 g/10 min or more, preferably 10 g/10 min or more, more preferably 10 to 20 g/10 min as measured at 220° C. under a load of 10 Kg according to ASTM D1238. Within this range, processability may be excellent.
For example, the non-graft copolymer (B) may have a refractive index of 1.52 to 1.55, preferably 1.53 to 1.54 as measured at room temperature using an Abbe refractometer according to ASTM D542. Within this range, since the difference in refractive index between the graft copolymer (A) and the seed is reduced, transparency, gloss, heat resistance, and weather resistance may be excellent.
In the present disclosure, room temperature may be within the range of 20±5° C.
For example, the non-graft copolymer (B) may be prepared by a method including step (i) of introducing a reaction mixture including 30 to 60% by weight of an alkyl (meth)acrylate, 25 to 55% by weight of an alkyl-substituted styrene-based compound, 5 to 35% by weight of a vinyl cyanide compound, a solvent, and a polyfunctional group-containing organic peroxide initiator into a polymerization reactor and performing bulk polymerization; and step (ii) of introducing the polymer reaction solution of step (i) into a volatilization tank and volatilizing the unreacted monomers and solvent to separate a polymer.
For example, the non-graft copolymer (B) may be prepared by solution polymerization, bulk polymerization, emulsion polymerization, or suspension polymerization, preferably bulk polymerization. Solution polymerization, bulk polymerization, emulsion polymerization, and suspension polymerization commonly practiced in the art to which the present invention pertains may be used in the present invention without particular limitation.
The bulk polymerization in step (i) may be performed preferably at 100 to 130° C. under the condition that residence time in the reactor is 6 to 8 hours.
The polymerization apparatus used for the polymerization reaction is not particularly limited, but a continuous polymerization apparatus in which two or more stirring tank-type reactors are connected in series is preferable. At this time, the reactor is not particularly limited, but the first reactor is preferably a stirring tank with a heat exchanger attached to the front end of the reactor, and the second reactor, the third reactor, or the like is preferably an evaporative stirring tank-type reactor including a stirring tank, a storage tank, a condenser, and a pressure control plate.
For example, the solvent may be toluene, methyl ethyl ketone, or a mixture thereof, preferably toluene. In this case, viscosity control may be easy, and polymerization conversion rate may be prevented from being reduced.
For example, the polyfunctional group-containing organic peroxide initiator may include one or more selected from the group consisting of 1,1-bis(t-butyl peroxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-butyl peroxy) cyclohexane, and 1,1-bis(t-butyl peroxy)-2-methylcyclohexane. In this case, productivity may be excellent, and heat-induced discoloration may be suppressed.
For example, based on 100 parts by weight in total of the alkyl-substituted styrene-based compound, the alkyl (meth)acrylate, and the vinyl cyanide compound, the organic peroxide initiator may be used in an amount of 0.05 to 0.3 parts by weight. Within this range, polymerization conversion rate and molecular weight may be increased.
Step (ii) may be performed through a conventional volatilization and separation process using a conventional volatilization tank. For example, a reaction solution (polymer reaction solution) that is polymerized in and discharged from a continuous polymerization apparatus is introduced into a first volatilization tank equipped with a heat exchanger, set to a temperature of 100 to 200° C. and a vacuum pressure of 500 to 650 torr, and the reaction solution discharged from the first volatilization tank is introduced into a second volatilization tank equipped with a heat exchanger, set to a temperature of 200 to 250° C. and a vacuum pressure of 50 torr or less, preferably 20 to 30 torr to volatilize unreacted monomers and solvents. Then, the reaction product is condensed, the condensed reaction product is reintroduced as a raw material, and the reaction product is passed through a transfer pump extruder to obtain a polymer in the form of pellets.
For example, based on the total weight of the graft copolymer (A) and the non-graft copolymer (B), the non-graft copolymer (B) may be included in an amount of 10 to 90% by weight, preferably 30 to 70% by weight, more preferably 40 to 60% by weight. Within this range, transparency, gloss, heat resistance, weather resistance, and impact resistance may be excellent.
In the present disclosure, a polymer including a certain compound means a polymer prepared by polymerizing the compound, and a unit in the polymer is derived from the compound.
(C) Alkyl acrylate-Aromatic Vinyl Compound-Vinyl Cyanide Compound Graft Copolymer Containing Rubber Core Having Average Particle Diameter of 50 to 150 nm
For example, the thermoplastic resin composition may include the alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (C) containing a rubber core having an average particle diameter of 50 to 150 nm. In this case, compatibility with the non-graft copolymer (B) may be excellent, and transparency, gloss, heat resistance, and weather resistance may be further improved.
The graft copolymer (C) may have an average particle diameter of preferably 50 to 150 nm, more preferably 70 to 130 nm, still more preferably 80 to 110 nm. Within this range, physical property balance and impact resistance may be excellent.
For example, the graft copolymer (C) may be preferably a graft copolymer including a rubber core including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound and a graft shell surrounding the rubber core and including 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl acrylate. In this case, compatibility with the non-graft copolymer (B) may be excellent, and transparency, gloss, heat resistance, and weather resistance may be further improved.
The graft copolymer (C) may include more preferably a rubber core including 80 to 90% by weight of an alkyl acrylate and 10 to 20% by weight of an aromatic vinyl compound and a graft shell surrounding the rubber core and including 67 to 77% by weight of an aromatic vinyl compound, 14 to 22% by weight of a vinyl cyanide compound, and 5 to 12% by weight of an alkyl acrylate. In this case, compatibility with the non-graft copolymer (B) may be excellent, and transparency, gloss, heat resistance, and weather resistance may be further improved.
The graft copolymer (C) may include still more preferably a rubber core including 82 to 88% by weight of an alkyl acrylate and 12 to 18% by weight of an aromatic vinyl compound and a graft shell surrounding the rubber core and including 70 to 75% by weight of an aromatic vinyl compound, 17 to 22% by weight of a vinyl cyanide compound, and 5 to 10% by weight of an alkyl acrylate. In this case, compatibility with the non-graft copolymer (B) may be excellent, and transparency, gloss, heat resistance, and weather resistance may be further improved.
For example, the graft copolymer (C) may include 30 to 60% by weight of the rubber core and 40 to 70% by weight of the graft shell, preferably 35 to 55% by weight of the rubber core and 45 to 65% by weight of the graft shell, more preferably 40 to 50% by weight of the rubber core and 50 to 60% by weight of the graft shell. Within this range, mechanical properties may be excellent.
The types of the alkyl acrylate, the aromatic vinyl compound, and the vinyl cyanide compound included in the graft copolymer (C) may be the same as the types of the alkyl acrylate, the aromatic vinyl compound, and the vinyl cyanide compound included in the graft copolymer (A).
For example, a method of preparing the graft copolymer (C) may include step (i) of preparing a rubber core by including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound; and step (ii) of preparing a graft copolymer by graft-polymerizing 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl acrylate in the presence of the rubber core. In this case, transparency, gloss, heat resistance, and weather resistance may be excellent.
The method of preparing the graft copolymer (C) may include preferably step (i) of preparing a rubber core by including 78 to 90% by weight of an alkyl acrylate, 10 to 22% by weight of an aromatic vinyl compound, a crosslinking agent, an initiator, and an emulsifier; and step (iii) of preparing a graft copolymer by graft-polymerizing 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, 3 to 15% by weight of an alkyl acrylate, a crosslinking agent, an initiator, and an emulsifier in the presence of the rubber core. In this case, transparency, gloss, heat resistance, and weather resistance may be excellent.
The types of the crosslinking agent, the initiator, and the emulsifier used in steps (i) and/or (ii) may be the same as the types of the crosslinking agent, the initiator, and the emulsifier used in the emulsion polymerization step of the graft copolymer (A) of the present invention.
For example, based on 100% by weight in total of the graft copolymer (A), the non-graft copolymer (B), and the graft copolymer (C), the total weight of the graft copolymer (A) and the graft copolymer (C) may be 10 to 90% by weight, preferably 30 to 70% by weight, more preferably 40 to 60% by weight. Within this range, transparency, gloss, heat resistance, weather resistance, and impact resistance may be excellent.
For example, the weight ratio (A:C) of the graft copolymer (A) to the graft copolymer (C) may be 5:5 to 7:3, preferably 5.5:4.5 to 6.5:3.5, more preferably 5.7:4.3 to 6.2:3.8. Within this range, transparency, gloss, heat resistance, weather resistance, and impact resistance may be excellent.
When acetone is added to the thermoplastic resin composition, stirring and centrifugation are performed to separate the thermoplastic resin composition into an insoluble sol and a soluble gel, and then refractive indexes thereof are measured, a difference between the refractive index of the sol and the refractive index (μD25) of the gel may be preferably 0.005 or less, more preferably 0.004 or less, still more preferably 0.003 or less, still more preferably 0.0001 to 0.003. Within this range, transparency and gloss may be excellent.
In the present disclosure, specifically, when measuring the refractive index difference between the sol and gel of the thermoplastic resin composition, 30 g of acetone is added to 0.5 g of thermoplastic resin composition pellets, stirring is performed at 210 rpm and room temperature for 12 hours using a shaker (SKC-6075, Lab Companion Co.), and centrifugation is performed at 18,000 rpm and 0° C. for 3 hours using a centrifuge (Supra R30, Hanil Science Co.) to separate a gel insoluble in acetone and a sol soluble in acetone. Then, the gel and the sol are dried via forced circulation at 85° C. for 12 hours using a forced convection oven (OF-12GW, Lab Companion Co.), and the refractive indexes of the gel and the sol are measured according to ASTM D542.
In the present disclosure, specifically, the refractive index is measured at room temperature using an Abbe refractometer according to ASTM D542.
The present invention has an effect of providing a resin composition having excellent transparency and gloss by controlling the refractive index difference of the sol and the gel within the above range.
The thermoplastic resin composition may have a haze of preferably 6.5% or less, more preferably 6% or less, still more preferably 5.5% or less, still more preferably 0.1 to 5.5%, still more preferably 0.1 to 5% as measured using an injection specimen having a thickness of 3 mm according to ASTM D1003. Within this range, physical property balance may be excellent.
The thermoplastic resin composition may have a haze of preferably 2.5% or less, more preferably 2% or less, still more preferably 0.1 to 2%, still more preferably 0.1 to 1.7% as measured using an extrusion specimen having a thickness of 0.15 mm according to ASTM D1003. Within this range, physical property balance may be excellent.
In the present disclosure, specifically, the haze of each of an injection specimen having a thickness of 3 mm and an extrusion specimen having a thickness of 0.15 mm may be measured using a haze meter (model name: HM-150, MURAKAMI Co.) according to ASTM D1003. As a haze value decreases, transparency increases.
The thermoplastic resin composition has a gloss of preferably 110 or more, more preferably 120 or more, still more preferably 125 or more, still more preferably 130 or more, still more preferably 135 or more, still more preferably 135 to 150 as measured at 45° using an injection specimen having a thickness of 3 mm according to ASTM D2457. Within this range, physical property balance may be excellent.
The thermoplastic resin composition has a gloss of preferably 110 or more, more preferably 120 or more, still more preferably 125 or more, still more preferably 125 to 150 as measured at 60° using an extrusion specimen having a thickness of 0.15 mm according to ASTM D2457. Within this range, physical property balance may be excellent.
The thermoplastic resin composition may have an Izod impact strength of preferably 14.5 kgf·cm/cm or more, more preferably 16 kgf·cm/cm or more, still more preferably 16 to 20 kgf·cm/cm, still more preferably 16.5 to 19 kgf·cm/cm as measured at room temperature using a specimen having a thickness of ¼″ according to ASTM D256. Within this range, physical property balance may be excellent.
The thermoplastic resin composition may have a heat deflection temperature of preferably 87° C. or higher, more preferably 89° C. or higher, still more preferably 89 to 105° C. as measured under a load of 18.5 kgf according to ASTM D648. Within this range, physical property balance and heat resistance may be excellent.
The thermoplastic resin composition may have a Vicat softening temperature of preferably 85° C. or higher, more preferably 88° C. or higher, still more preferably 90° C. or higher, still more preferably 90 to 105° C. as measured at a heating rate of 50° C./h under a load of 50 N according to ASTM D1525. Within this range, physical property balance and heat resistance may be excellent.
After leaving an specimen for 3,000 hours in an accelerated weather resistance tester (Weather-O-Meter, Ci4000, ATLAS Co., xenon arc lamp, Quartz (inner)/S.Boro (outer) filters, irradiance of 0.55 W/m2 at 340 nm) according to SAE J1960, when the degree of discoloration is measured using a color difference meter, and weather resistance (ΔE) is calculated by Equation 7 below, the thermoplastic resin composition may have a weather resistance (ΔE) of preferably 2.6 or less, more preferably 2.4 or less, still more preferably 0.1 to 2.4. Within this range, physical property balance may be excellent.
ΔE is an arithmetic mean value of L, a, and b values of the specimen measured by the CIE LAB color coordinate system before and after the accelerated weather resistance test. Weather resistance increases as the value of ΔE approaches zero.
For example, the thermoplastic resin composition may include one or more selected from the group consisting of a lubricant, an antioxidant, and a UV absorber.
For example, the lubricant may include one or more selected from the group consisting of ethylene bis stearamide, oxidized polyethylene wax, magnesium stearate, calcium stearamide, and stearic acid. In this case, heat resistance and fluidity may be improved.
For example, based on 100 parts by weight in total of the graft copolymer (A) and the non-graft copolymer (B), the lubricant may be included in an amount of 0.01 to 3 parts by weight, preferably 0.05 to 2 parts by weight.
For example, the antioxidant may be a phenol-based antioxidant, a phosphorus-based antioxidant, or a mixture thereof, preferably a phenol-based antioxidant. In this case, oxidation by heat may be prevented during an extrusion process, and mechanical properties and heat resistance may be excellent.
For example, based on 100 parts by weight in total of the graft copolymer (A) and the non-graft copolymer (B), the antioxidant may be included in an amount of 0.01 to 3 parts by weight, preferably 0.05 to 2 parts by weight. Within this range, physical property balance may be excellent, and heat resistance may be improved.
For example, the UV absorber may include one or more selected from the group consisting of a triazine-based UV absorber, a benzophenone-based UV absorber, a benzotriazole-based UV absorber, a benzoate-based UV absorber, and a cyanoacrylate-based UV absorber, without being limited thereto.
For example, based on 100 parts by weight in total of the graft copolymer (A) and the non-graft copolymer (B), the UV absorber may be included in an amount of 0.01 to 3 parts by weight, preferably 0.05 to 2 parts by weight. Within this range, physical property balance may be excellent, and light resistance may be improved.
For example, the thermoplastic resin composition may further include one or more additives selected from the group consisting of a fluorescent brightening agent, an antistatic agent, a chain extender, a release agent, a pigment, a dye, an antibacterial agent, a processing aid, a metal deactivator, a smoke suppressant, an inorganic filler, glass fiber, an anti-friction agent, and an anti-wear agent.
For example, based on 100 parts by weight in total of the graft copolymer (A) and the non-graft copolymer (B), each of the additives may be included in an amount of 0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight, more preferably 0.1 to 1 part by weight. In this case, physical properties may be improved, and economics may be excellent due to reduction in preparation cost.
Hereinafter, a method of preparing the thermoplastic resin composition of the present invention and a molded article including the same will be described. In describing the method and the molded article, all of the above-described thermoplastic resin composition is included.
The method of preparing the thermoplastic resin composition of the present invention includes a step of kneading and extruding, at 180 to 300° C. and 80 to 400 rpm, an alkyl (meth)acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A) including a polymer seed including 51 to 77% by weight of an alkyl (meth)acrylate and 23 to 49% by weight of an aromatic vinyl compound, a rubber core surrounding the polymer seed and including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound, and a graft shell surrounding the rubber core and including 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl acrylate; and a non-graft copolymer (B) including an alkyl (meth)acrylate, an alkyl-substituted styrene-based compound, and a vinyl cyanide compound, wherein the graft copolymer (A) satisfies both Equations 1 and 2 below. In this case, transparency, gloss, and impact resistance may be excellent.
In Equations 1 and 2, r1 represents an average radius (nm) from the center of the graft copolymer to the seed, and r2 represents an average radius (nm) from the center of the graft copolymer to the core.
For example, in the step of kneading and extruding, an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (C) containing a rubber core having an average particle diameter of 50 to 150 nm may be included. Preferably, an alkyl acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (C) containing a rubber core having an average particle diameter of 50 to 150 nm and including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound and a graft shell surrounding the rubber core and including 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl acrylate may be included. In this case, transparency, gloss, heat resistance, and weather resistance may be greatly improved.
For example, the kneading and extrusion may be performed using a single-screw extruder, a twin-screw extruder, and a Banbury mixer. In this case, the composition may be uniformly distributed, and thus compatibility may be excellent.
For example, the kneading and extrusion may be performed at a barrel temperature of 180 to 300° C., preferably 190 to 280° C., more preferably 200 to 260° C. In this case, throughput per unit time may be appropriate, melt-kneading may be sufficiently performed, and problems such as thermal decomposition of resin components do not occur.
For example, the kneading and extrusion may be performed at a screw rotation speed of 80 to 400 rpm, preferably 100 to 300 rpm, more preferably 150 to 250 rpm. In this case, throughput per unit time may be appropriate, and process efficiency may be excellent.
For example, the thermoplastic resin composition obtained by extrusion may be made into pellets using a pelletizer.
In addition, the resin composition may be manufactured into a molded article used in various industrial fields through a molding process such as a blow process and an injection process.
For example, a molded article of the present invention may include the thermoplastic resin composition of the present invention. Since the molded article has excellent transparency, gloss, heat resistance, weather resistance, and impact resistance, the high-quality molded article may be applied to fields requiring transparency.
For example, the molded article may be an injection-molded article, a film, or a sheet. In this case, since the molded article includes the thermoplastic resin composition of the present invention, the high-quality molded article that may sufficiently satisfy the market demand for transparency, gloss, heat resistance, weather resistance, and impact resistance may be provided.
For example, the molded article may be an automotive interior material, an automotive exterior material, a building material, a home appliance, or a medical part. In this case, since transparency, gloss, heat resistance, weather resistance, and impact resistance are excellent, all market requirements may be satisfied.
A method of manufacturing the molded article preferably includes a step of preparing pellets by kneading and extruding, at 180 to 300° C. and 80 to 400 rpm, an alkyl (meth)acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A) including a polymer seed including 51 to 77% by weight of an alkyl (meth)acrylate and 23 to 49% by weight of an aromatic vinyl compound, a rubber core surrounding the polymer seed and including 78 to 90% by weight of an alkyl acrylate and 10 to 22% by weight of an aromatic vinyl compound, and a graft shell surrounding the rubber core and including 65 to 80% by weight of an aromatic vinyl compound, 14 to 25% by weight of a vinyl cyanide compound, and 3 to 15% by weight of an alkyl acrylate; and a non-graft copolymer (B) including an alkyl (meth)acrylate, an alkyl-substituted styrene-based compound, and a vinyl cyanide compound and a step of injecting or extruding the prepared pellets using an injection machine or an extruder, wherein the graft copolymer (A) satisfies both Equations 1 and 2 below. In this case, a molded article having excellent transparency, gloss, heat resistance, weather resistance, and impact resistance may be manufactured, and the high-quality molded article may be applied to fields requiring transparency.
In Equations 1 and 2, r1 represents an average radius (nm) from the center of the graft copolymer to the polymer seed, and r2 represents an average radius (nm) from the center of the graft copolymer to the rubber core.
Hereinafter, the present invention will be described in more detail with reference to the following preferred examples. However, these examples are provided for illustrative purposes only and should not be construed as limiting the scope and spirit of the present invention. In addition, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention, and such changes and modifications are also within the scope of the appended claims.
Materials used in Examples and Comparative Examples are as follows.
An acrylate-styrene-acrylonitrile graft copolymer (A) including a polymer seed including methyl methacrylate (hereinafter referred to as “MMA”) and styrene (hereinafter referred to as “SM”) in a weight ratio of 55/45, a rubber core including butyl acrylate (hereinafter referred to as “BA”) and SM in a weight ratio of 85/15, and a graft shell including SM, acrylonitrile (hereinafter referred to as “AN”), and BA in a weight ratio of 76/16/8 was prepared. In this case, in the graft copolymer (A), 20% by weight of the polymer seed, 40% by weight of the rubber core, and 40% by weight of the graft shell were included.
1 part by weight of a lubricant, 1 part by weight of an antioxidant, and 0.6 parts by weight of an UV absorber were added to 50 parts by weight of the prepared graft copolymer (A) and 50 parts by weight of AMS T-SAN copolymer (B-1), and kneading and extrusion were performed at 220° C. and 200 rpm to prepare pellets. The prepared pellets were injected at a molding temperature of 220° C. to prepare an injection specimen for measuring physical properties. In addition, the prepared pellets were extruded at 220° C. and 200 rpm using a single-screw film extruder to prepare an extrusion specimen for measuring physical properties.
The same procedure as in Example 1 was performed except that, instead of the graft copolymer (A) of Example 1, the graft copolymer (A) polymerized according to the components and contents shown in Tables 1 and 2 was used.
The same procedure as in Example 7 was performed except that, instead of 50 parts by weight of the graft copolymer (A) prepared in Example 7, 30 parts by weight of the graft copolymer (A) and 20 parts by weight of the graft copolymer (C) were used.
The same procedure as in Example 7 was performed except that, instead of 50 parts by weight of the graft copolymer (A) prepared in Example 7, 35 parts by weight of the graft copolymer (A) and 15 parts by weight of the graft copolymer (C) were used.
The same procedure as in Example 1 was performed except that, instead of the graft copolymer (A) of Example 1, the graft copolymer (A) polymerized according to the components and contents shown in Tables 3 and 4 below was used.
The same procedure as in Example 1 was performed except that a polymer seed including 100% by weight of MA, a rubber core including BA and SM in a weight ratio of 81/19, and a graft shell including 100% by weight of MMA were used to prepare a graft copolymer.
The same procedure as in Example 5 was performed except that, instead of the AMS T-SAN copolymer (B-1) of Example 5, the SAMMA copolymer (B-2) was used.
A transparent acrylonitrile-butadiene-styrene resin (TR557, LG Chemical Co.) was injected to prepare an injection specimen for measuring physical properties.
The properties of the pellets and specimens prepared in Examples 1 to 10 and Comparative Examples 1 to 12 were measured by the following methods, and the results are shown in Tables 1 to 4 below.
Wti=Weight fraction (%) of each component of copolymer
RIi=Refractive index of polymer of each component of copolymer
Note that, r1 was a value obtained by dividing the average particle diameter of the seed by 2, and r2 was a value obtained by dividing the average particle diameter of the seed-containing core by 2.
In Equation 7, L′, a′, and b′ are respectively L, a, and b values measured using the CIE LAB color coordinate system after leaving a specimen for 3,000 hours according to SAE J1960, and L0, a0, and b0 are respectively L, a, and b values measured using the CIE LAB color coordinate system before leaving the specimen.
As shown in Tables 1 to 4, it can be confirmed that the thermoplastic resin compositions (Examples 1 to 10) according to the present invention have physical properties, such as heat deflection temperature and Vicat softening temperature, equal to or superior to those of the thermoplastic resin compositions of Comparative Examples 1 to 12. In addition, the thermoplastic resin compositions according to the present invention have excellent impact strength, haze, gloss, and weather resistance. Note that, the injection specimens and extrusion specimens of Examples 9 and 10 including the graft copolymer (A) and the graft copolymer (C) have excellent haze and gloss.
On the other hand, in the case of Comparative Examples 1 and 2 in which the composition ratio of the polymer seed of the graft copolymer (A) is out of the range of the present invention, since the difference between the refractive index of the polymer seed of the graft copolymer (A) and the refractive index of the non-graft copolymer (B) and the difference in refractive index between a sol and a gel in the thermoplastic resin composition are large, the haze, gloss, and impact strength of both injection and extrusion specimens are poor.
In addition, in the case of Comparative Examples 3 and 4 in which the composition of the rubber core of the graft copolymer (A) is out of the range of the present invention, the difference in refractive index between the rubber core and shell of the graft copolymer (A) is out of the range of 0.08 to 0.09. In addition, since the refractive index difference between a sol and a gel in the thermoplastic resin composition increases, the haze and gloss of both injection and extrusion specimens are poor. In particular, in the case of Comparative Example 4, impact strength is very low.
In addition, in the case of Comparative Examples 5 and 6 in which the composition of the graft shell of the graft copolymer (A) is out of the range of the present invention, the difference in refractive index between the rubber core and shell of the graft copolymer (A) is out of the range of 0.08 to 0.09. In addition, since the refractive index difference between a sol and a gel in the thermoplastic resin composition increases, the haze and gloss of both injection and extrusion specimens are poor. In addition, impact strength is also low.
In addition, in the case of Comparative Example 7 in which 2*r2 and r2-r1 of the rubber core of the graft copolymer (A) exceed out of the range of the present invention, the haze and gloss of both injection and extrusion specimens are poor. In the case of Comparative Example 8 in which 2*r2 and r2-r1 of the rubber core of the graft copolymer (A) are less than the range of the present invention, impact strength is very poor.
In addition, in the case of Comparative Example 9 including only styrene in the seed and only butyl acrylate in the rubber core as in the prior art, the difference between the refractive index of the rubber core of the graft copolymer (A) and the refractive index of the shell is out of the range of 0.08 to 0.09. The difference in refractive index between the polymer seed of the graft copolymer (A) and the non-graft copolymer (B) and the refractive index difference between a sol and a gel in the thermoplastic resin composition increase, resulting in deterioration of the haze and gloss of injection and extrusion specimen.
In addition, in the case of Comparative Example 10 in which methyl methacrylate is included in the seed and shell of the graft copolymer (A), respectively, the difference between the refractive index of the rubber core of the graft copolymer (A) and the refractive index of the shell is out of the range of 0.08 to 0.09, and the difference in refractive index between the polymer seed of the graft copolymer (A) and the non-graft copolymer (B) and the refractive index difference between a sol and a gel in the thermoplastic resin composition increase, resulting in deterioration of the haze, gloss, impact strength, and weather resistance of injection and extrusion specimens.
In addition, in the case of Comparative Example 11 in which the SAMMA copolymer (B-2) is used as the non-graft copolymer, the difference in refractive index between the polymer seed of the graft copolymer (A) and the SAMMA copolymer (B-2) and the refractive index difference between a sol and a gel in the thermoplastic resin composition increase. As a result, the haze, gloss, impact strength, heat deflection temperature, and Vicat softening temperature of injection and extrusion specimens are reduced, and thus the heat resistance thereof is reduced.
In addition, in the case of Comparative Example 12 in which the transparent acrylonitrile-butadiene-styrene resin is used, weather resistance is very poor.
In conclusion, when the composition and composition ratio of the polymer seed, core, and shell constituting the graft copolymer (A) of the thermoplastic resin composition including the alkyl (meth)acrylate-aromatic vinyl compound-vinyl cyanide compound graft copolymer (A) and the non-graft copolymer (B) including an alkyl (meth)acrylate, an alkyl-substituted styrene-based compound, and a vinyl cyanide compound are adjusted within a predetermined range, and the difference between the refractive index of the core and the refractive index of the shell and the difference between the refractive index of the polymer seed of the graft copolymer (A) and the refractive index of the non-graft copolymer (B) are reduced, impact resistance, transparency, gloss, heat resistance, and weather resistance may be excellent.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0141872 | Oct 2021 | KR | national |
| 10-2022-0104724 | Aug 2022 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/012702 | 8/25/2022 | WO |
