KR102846007B1 - Thermoplastic resin composition - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition comprising a rubbery polymer having a gel content of 0 to 10 wt% and including vinyl aromatic monomer units and diene monomer units, a graft polymer comprising a shell including (meth)acrylate monomer units and vinyl aromatic monomer units grafted onto the rubbery polymer, and a non-graft polymer comprising 90 wt% or more of (meth)acrylate monomer units.

Description

Thermoplastic resin composition

[Cross-citation with related applications]

This invention claims the benefit of priority from Korean Patent Application No. 10-2021-0098177, filed July 26, 2021, the entire contents of which are incorporated herein by reference.

[Technical Field]

The present invention relates to a thermoplastic resin composition, and more particularly, to a thermoplastic resin composition capable of achieving excellent impact resistance, scratch resistance, matte properties, and processability.

Diene rubber polymers are widely used as impact modifiers for various thermoplastic polymers, such as graft polymers, due to their excellent rubber properties. Graft polymers can be widely used as materials for electrical appliances, electronic devices, automotive parts, and general office supplies, and can be produced by graft polymerizing diene rubber polymers with vinyl aromatic monomers and vinyl cyanide monomers.

Meanwhile, the gel content of diene-based rubber polymers affects the impact resistance of graft polymers. To control the gel content, an excess of a molecular weight modifier is required. However, excessive use of a molecular weight modifier results in a reduced polymerization rate, which prolongs the polymerization time and reduces manufacturing efficiency.

In addition, as industries have advanced and lifestyles have become more diverse, there has been a need to provide high functionality, such as matte properties, while also enabling injection molding in complex structures. However, it has been difficult for graft polymers using diene rubber polymers to achieve both excellent matte properties and processability. Embossing a mold to achieve matte properties has been proposed, but there has been a limitation in that matte properties cannot be achieved with a general mold. Furthermore, the use of matting agents has been proposed to achieve matte properties, but the matting agents not only increase manufacturing costs but also deteriorate basic physical properties, resulting in poor matte properties.

Accordingly, a method is being studied to improve impact resistance by adjusting the gel content, while improving matte properties, scratch resistance, processability, and manufacturing efficiency.

JP1995-025975B

The purpose of the present invention is to provide a thermoplastic resin composition capable of implementing excellent impact resistance, scratch resistance, matte properties, and processability.

In order to solve the above-described problem, 1) the present invention provides a thermoplastic resin composition comprising a rubbery polymer having a gel content of 0 to 10 wt% and including a vinyl aromatic monomer unit and a diene monomer unit, a graft polymer including a shell including a (meth)acrylate monomer unit and a vinyl aromatic monomer unit grafted onto the rubbery polymer, and a non-graft polymer including 90 wt% or more of a (meth)acrylate monomer unit.

2) The present invention provides a thermoplastic resin composition in which, in the above 1), the rubber polymer has a gel content of 0 to 5 wt%.

3) The present invention provides a thermoplastic resin composition according to 1) or 2), wherein the rubber polymer contains the vinyl aromatic monomer unit and the diene monomer unit in a weight ratio of 10:90 to 35:65.

4) The present invention provides a thermoplastic resin composition in any one of 1) to 3) above, wherein the rubber polymer has an average particle diameter of 20 to 100 nm.

5) The present invention provides a thermoplastic resin composition according to any one of 1) to 4), wherein the graft polymer comprises 30.0 to 65.0 wt% of the rubber polymer; 10.0 to 55.0 wt% of the (meth)acrylate monomer unit; and 5.0 to 40.0 wt% of the vinyl aromatic monomer unit.

6) The present invention provides a thermoplastic resin composition in which, in any one of the above 1) to 5), the non-graft polymer comprises at least one selected from the group consisting of (meth)acrylic acid monomer units and vinyl aromatic monomer units.

7) The present invention provides a thermoplastic resin composition according to any one of 1) to 6), wherein the thermoplastic resin composition comprises 10.0 to 50.0 wt% of the graft polymer and 50.0 to 90.0 wt% of the non-graft polymer.

8) The present invention provides a thermoplastic resin composition according to any one of 1) to 7), wherein the shell of the graft polymer includes a vinyl cyanide monomer unit grafted onto the rubbery polymer.

9) The present invention provides a thermoplastic resin composition according to any one of 1) to 8), wherein the thermoplastic resin composition comprises 5.0 to 25.0 wt% of the rubber polymer; 60.0 to 90.0 wt% of the (meth)acrylate monomer unit; and 3.0 to 20.0 wt% of the vinyl aromatic monomer unit.

The thermoplastic resin composition according to the present invention can realize excellent impact resistance, scratch resistance, matte properties, and processability.

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.

In the present invention, the gel content is obtained by coagulating a rubber polymer latex using a dilute acid or a metal salt, then washing it, and drying it in a vacuum oven at 60°C for 24 hours to obtain a rubber lump. The rubber lump is cut into small pieces with scissors to prepare a 1-g rubber segment, and the rubber segment is placed in 100 g of toluene, stored in a dark room at 23°C for 48 hours, and then the sol and gel are separated. The sol and gel are substituted into the following equation to calculate the gel content. Here, the type of the dilute acid is not particularly limited, but is preferably at least one selected from the group consisting of hydrochloric acid, sulfuric acid, and formic acid. In addition, the type of the metal salt is not particularly limited, but is preferably at least one selected from the group consisting of magnesium sulfate, calcium chloride, and aluminum sulfate.

Gel content (wt%) = weight of gel / weight of rubber section × 100

In the present invention, the refractive index refers to the absolute refractive index of a material, and the refractive index can be recognized as the ratio of the speed of electromagnetic radiation in free space to the speed of radiation within the material. In this case, the radiation may be visible light having a wavelength of 450 nm to 680 nm, and specifically, visible light having a wavelength of 589.3 nm. The refractive index can be measured using a known method, i.e., an Abbe refractometer.

In the present invention, after the graft polymer and the non-graft polymer are spread to a thickness of 0.2 mm, the refractometer can be used to measure the refractometer using visible light having a wavelength of 589.3 nm at 25°C.

In the present invention, the average particle diameter can be measured using the dynamic light scattering method, and more specifically, can be measured using the Nicomp 380 equipment of Particle Sizing Systems Co., Ltd. In the present invention, the average particle diameter can mean the arithmetic mean particle diameter in the particle size distribution measured by the dynamic light scattering method, i.e., the average particle diameter of the scattering intensity (Intensity Distribution).

In the present invention, the average particle diameter can be measured using a transmission electron microscope (TEM).

In the present invention, the weight of the rubber polymer, diene monomer unit, (meth)acrylate monomer unit, vinyl aromatic monomer unit, and vinyl cyanide monomer unit included in the thermoplastic resin composition can be measured by infrared spectroscopy. At this time, the infrared spectroscopy measuring device that can be used is a NicoletTM iS20 FTIR Spectrometer (model name, manufacturer: Thermo Scientific).

In the present invention, the polymerization conversion rate indicates the degree to which monomers polymerize to form a polymer, and can be calculated by the following formula.

Polymerization conversion rate (%) = {(Total weight of monomers introduced until polymerization is complete) - (Total weight of unreacted monomers at the time of measuring polymerization conversion rate)} / (Total weight of monomers introduced until polymerization is complete) × 100

In the present invention, the diene monomer unit may be a unit derived from a diene monomer. The diene monomer unit may be at least one selected from the group consisting of 1,3-butadiene, isoprene, chloroprene, and piperylene, and among these, 1,3-butadiene is preferred.

In the present invention, the vinyl aromatic monomer unit may be a unit derived from a vinyl aromatic monomer. The vinyl aromatic monomer may be at least one selected from the group consisting of styrene, α-methyl styrene, α-ethyl styrene, and p-methyl styrene, and among these, styrene is preferred.

In the present invention, the (meth)acrylate monomer unit may be a unit derived from a (meth)acrylate monomer. The (meth)acrylate monomer may be a C ₁ to C ₁₀ alkyl (meth)acrylate monomer, and the C ₁ to C ₁₀ alkyl (meth)acrylate monomer may be at least one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, heptyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and decyl (meth)acrylate, and among these, methyl methacrylate is preferred.

In the present invention, the vinyl cyanide monomer unit may be a unit derived from a vinyl cyanide monomer. The vinyl cyanide monomer may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, phenylacrylonitrile, and α-chloroacrylonitrile, and among these, acrylonitrile is preferred.

In the present invention, the (meth)acrylic acid monomer unit may be at least one selected from the group consisting of acrylic acid and methacrylic acid.

In the present invention, the emulsifier may be at least one selected from the group consisting of sodium dicyclohexyl sulfosuccinate, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, sodium octadecyl sulfate, sodium oleyl sulfate, potassium dodecyl sulfate, potassium octadecyl sulfate, potassium oleate, sodium oleate, potassium rosinate, and sodium rosinate. Among these, at least one selected from the group consisting of potassium oleate, sodium oleate, and potassium rosinate is preferable.

In the present invention, the initiator may be at least one selected from the group consisting of potassium persulfate, sodium persulfate, ammonium persulfate, cumene hydroperoxide, diisopropyl benzene hydroperoxide, azobisisobutyronitrile, t-butyl hydroperoxide, paramenthane hydroperoxide, benzoyl peroxide, and 1,1-bis(t-butylperoxy)cyclohexane, and among these, at least one selected from the group consisting of potassium persulfate, cumene hydroperoxide, and 1,1-bis(t-butylperoxy)cyclohexane is preferable.

In the present invention, the molecular weight modifier may be at least one selected from the group consisting of α-methyl styrene dimer, t-dodecyl mercaptan, n-dodecyl mercaptan, t-octyl mercaptan, n-octyl mercaptan, carbon tetrachloride, methylene chloride, methylene bromide, tetraethyl thiuram disulfide, dipentamethylene thiuram dipulfide, and diisopropyl xanthogene disulfide. Among these, t-dodecyl mercaptan is preferred.

In the present invention, the oxidation-reduction catalyst may be at least one selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, iron (II) sulfate, dextrose, tetrasodium pyrophosphate, anhydrous sodium pyrophosphate, and sodium sulfate, and among these, it is preferable that it is at least one selected from the group consisting of iron (II) sulfate, dextrose, and tetrasodium pyrophosphate.

In the present invention, the aqueous solvent may be ion-exchanged water or deionized water.

1. Thermoplastic resin composition

A thermoplastic resin composition according to one embodiment of the present invention comprises a rubbery polymer having a gel content of 0 to 10 wt% and including a vinyl aromatic monomer unit and a diene monomer unit, a graft polymer including a shell including a (meth)acrylate monomer unit and a vinyl aromatic monomer unit grafted onto the rubbery polymer, and a non-graft polymer including 90 wt% or more of a (meth)acrylate monomer unit.

The graft polymer and non-graft polymer included in the thermoplastic resin composition according to the present invention may have a difference in refractive index of 0.0350 or more, preferably 0.0400 or more. When the above-described conditions are satisfied, the thermoplastic resin composition may have opaque properties.

The thermoplastic resin composition according to the present invention may contain 10.0 to 50.0 wt% of the graft polymer and 50.0 to 90.0 wt% of the non-graft polymer, preferably 15.0 to 45.0 wt% of the graft polymer and 55.0 to 85.0 wt% of the non-graft polymer, and more preferably 15.0 to 35.0 wt% of the graft polymer and 65.0 to 85.0 wt% of the non-graft polymer. When the above-described conditions are satisfied, the thermoplastic resin composition can realize excellent impact resistance and processability.

The thermoplastic resin composition according to the present invention may contain 5.0 to 25.0 wt%, preferably 10.0 to 20.0 wt%, of the rubber polymer. When the above-described conditions are satisfied, the thermoplastic resin composition can exhibit excellent impact resistance.

The thermoplastic resin composition according to the present invention may contain 60.0 to 90.0 wt%, preferably 65.0 to 85.0 wt%, of the (meth)acrylate monomer unit. When the above-described conditions are satisfied, the thermoplastic resin composition can exhibit excellent impact resistance and scratch resistance.

In addition, the thermoplastic resin composition according to the present invention may contain 3.0 to 20.0 wt%, preferably 8.0 to 15.0 wt%, of the vinyl aromatic monomer unit. When the above-described conditions are satisfied, the thermoplastic resin composition can exhibit excellent processability.

In addition, the thermoplastic resin composition according to the present invention may include the vinyl cyanide monomer unit. In this case, the content of the vinyl cyanide monomer unit may be 10.0 wt% or less, preferably 5 wt% or less. If the above-described conditions are satisfied, excellent chemical resistance can be realized while minimizing yellowing.

Hereinafter, the graft polymer and non-graft polymer, which are components of the present invention, will be described in detail.

1) Graft polymer

The graft polymer comprises a rubbery polymer having a gel content of 0 to 10 wt% and including vinyl aromatic monomer units and diene monomer units, and a shell comprising (meth)acrylate monomer units and vinyl aromatic monomer units grafted onto the rubbery polymer. The shell may further comprise (meth)acrylate monomer units and vinyl aromatic monomer units that are not grafted onto the rubbery polymer. In order to improve the chemical resistance of the graft polymer, the shell may further comprise a vinyl cyanide monomer unit that is or is not grafted onto the rubbery polymer.

The above rubber polymer may have a gel content of 0 to 10 wt%, preferably 0 to 5 wt%, and more preferably 0 to 1 wt%. When the above-described range is satisfied, the thermoplastic resin composition can realize excellent matte properties and impact resistance. However, when the above-described range is exceeded, the thermoplastic resin composition cannot realize matte properties and the impact resistance may be significantly reduced.

Meanwhile, the gel content of the rubber polymer can be controlled by the polymerization temperature and the final polymerization conversion ratio, and the rubber polymer satisfying the above-described gel content can be prepared by initiating and performing polymerization of a vinyl aromatic monomer unit and a diene monomer at 0 to 20°C, and terminating the polymerization at a point where the polymerization conversion ratio is 40 to 60%. Preferably, the rubber polymer satisfying the above-described gel content can be prepared by initiating and performing polymerization of a vinyl aromatic monomer unit and a diene monomer at 5 to 15°C, and terminating the polymerization at a point where the polymerization conversion ratio is 45 to 55%.

If either of the above-described polymerization temperature and polymerization end point is not satisfied, it may be difficult to produce a rubbery polymer satisfying the above-described gel content.

The above polymerization may be emulsion polymerization, and may be performed in the presence of at least one selected from the group consisting of an emulsifier, an initiator, a molecular weight regulator, a redox catalyst, and an aqueous solvent.

The content of the above emulsifier may be 1.0 to 10.0 parts by weight, preferably 3.0 to 7.0 parts by weight, based on 100 parts by weight of the total monomers used in the production of the rubber polymer. When the above-described conditions are satisfied, polymerization stability and latex stability can be improved, while the rubber polymer can be controlled to have a desired average particle size.

The content of the above initiator may be 0.1 to 0.5 parts by weight, preferably 0.1 to 0.3 parts by weight, based on 100 parts by weight of the total of monomers introduced during the production of the rubber polymer. When the above-described conditions are satisfied, emulsion polymerization can be stably initiated and performed.

The content of the above molecular weight regulator may be 0.1 to 1.7 parts by weight, preferably 0.3 to 1.5 parts by weight, and more preferably 0.5 to 1.3 parts by weight, based on 100 parts by weight of the total of monomers introduced during the production of the rubber polymer. When the above-described conditions are satisfied, the gel content of the rubber polymer can be finely controlled, and when the content of the molecular weight regulator increases, the gel content can decrease, and when the content of the molecular weight regulator decreases, the gel content can increase.

The content of the oxidation-reduction catalyst may be 0.010 to 0.100 parts by weight, preferably 0.030 to 0.080 parts by weight, based on 100 parts by weight of the total of monomers introduced during the production of the rubber polymer.

Meanwhile, when the rubbery polymer is a rubbery polymer containing only diene monomer units, the matrix region must contain an excessive amount of (meth)acrylate monomer units in order to eliminate or minimize the difference in refractive index between the impact-reinforced region and the matrix region of the thermoplastic resin composition. However, the (meth)acrylate monomer units cause a decrease in the chemical resistance of the thermoplastic resin composition, and the high unit price of the (meth)acrylate monomer causes an increase in the manufacturing cost. In addition, the rubbery polymer cannot be produced with only a vinyl aromatic monomer.

However, the rubber polymer can increase the refractive index of the rubber polymer by including not only a diene monomer unit but also a vinyl aromatic monomer unit, and thus it is possible to include a small amount of a (meth)acrylate monomer unit in the matrix region. Therefore, the thermoplastic resin composition according to the present invention can minimize the decrease in chemical resistance and the increase in manufacturing cost caused by the (meth)acrylate monomer unit.

The above rubber polymer may contain vinyl aromatic monomer units and diene monomer units in a weight ratio of 10:90 to 35:65, and preferably in a weight ratio of 15:85 to 30:70. When the above-described conditions are satisfied, impact resistance can be improved and refractive index can be increased, so that the amount of (meth)acrylate monomer units used can be reduced, and the decrease in chemical resistance and increase in manufacturing cost due to (meth)acrylate monomer units can be minimized.

Since the rubber polymer contains a diene monomer unit and a vinyl aromatic monomer in the weight ratio described above, it may have a higher refractive index than a rubber polymer composed solely of a diene monomer. As a specific example, the rubber polymer may have a refractive index of 1.5230 to 1.5420, preferably 1.5300 to 1.5400.

The above rubber polymer may have an average particle diameter of 20 to 100 nm, preferably 20 to 80 nm. When the above-described range is satisfied, excellent matte properties and impact resistance can be realized.

The above graft polymer may contain 30.0 to 65.0 wt%, preferably 35.0 to 60.0 wt%, of the rubber polymer. When the above-described range is satisfied, excellent impact resistance can be achieved.

The above graft polymer may contain 10.0 to 55.0 wt%, preferably 15.0 to 50.0 wt%, of the (meth)acrylate monomer unit. When the above-described range is satisfied, excellent scratch resistance can be achieved.

The above graft polymer may contain 5.0 to 40.0 wt%, preferably 10.0 to 35.0 wt%, of the vinyl aromatic monomer unit. When the above-described range is satisfied, excellent processability can be achieved.

The above graft polymer may further include a vinyl cyanide monomer unit, and may further include it at 7.0 wt% or less in order to minimize yellowing while implementing excellent chemical resistance. In this case, the content of the vinyl cyanide monomer unit may refer to the content of the vinyl cyanide monomer unit that is or is not grafted onto the rubber polymer.

The above graft copolymer may have a refractive index of 1.5230 to 1.5420, preferably 1.5300 to 1.5400. When the above-described range is satisfied, the refractive index is identical to or similar to that of the above-described rubber polymer, so that the transparency of the graft copolymer can be further improved.

2) Non-graft polymer

The non-graft polymer contains 90 wt% or more of (meth)acrylate monomer units. If the content of the (meth)acrylate monomer units is less than the above-described range, the scratch resistance and matte properties of the thermoplastic resin composition may deteriorate.

The above non-graft polymer may further include at least one comonomer selected from the group consisting of (meth)acrylic acid monomer units and vinyl aromatic monomer units to improve scratch resistance. The content of the comonomer may be included in a remainder such that the content of the monomer unit in the non-graft polymer is 100 wt%.

The above non-graft copolymer may have a refractive index of 1.4800 to 1.5000, preferably 1.4850 to 1.4950.

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.

Manufacturing Example 1

<Manufacture of rubber polymers>

Into a nitrogen-purged polymerization reactor (autoclave), 200 parts by weight of ion-exchanged water, 20 parts by weight of styrene, 80 parts by weight of 1,3-butadiene, 2.0 parts by weight of potassium oleate, 3.0 parts by weight of potassium rosinate, 0.1 part by weight of cumene hydroperoxide, 1.0 part by weight of t-dodecyl mercaptan, 0.010 part by weight of sodium pyrophosphate, 0.050 part by weight of dextrose, and 0.001 part by weight of iron (II) sulfate were charged all at once, and polymerized at 10°C. When the polymerization conversion rate reached 50%, polymerization was terminated, and a styrene/butadiene rubber polymer latex (gel content: 0 wt%, average particle diameter: 40 nm, refractive index: 1.5310) was manufactured.

<Manufacture of graft polymer>

A mixed solution containing 200 parts by weight of ion-exchanged water, 1.0 parts by weight of sodium oleate, 29.6 parts by weight of methyl methacrylate, 20.4 parts by weight of styrene, 0.6 parts by weight of t-dodecyl mercaptan, 0.050 parts by weight of ethylenediaminetetraacetic acid, 0.100 parts by weight of sodium formaldehyde sulfoxylate, 0.001 parts by weight of iron (II) sulfate, and 0.2 parts by weight of cumene hydroperoxide was prepared.

50 parts by weight (based on solid content) of the styrene/butadiene rubber polymer latex was introduced into the reactor. Thereafter, the mixed solution was continuously introduced into the reactor at 60°C for 5 hours to polymerize. After the continuous introduction of the mixed solution was completed, the mixture was aged at 60°C for 1 hour to complete the polymerization, thereby producing a graft polymer latex. The entire amount of the prepared graft polymer latex was introduced into an aqueous solution containing 2 parts by weight of calcium chloride, coagulated, aged, washed, dehydrated, and dried to produce a graft polymer powder (refractive index: 1.5310).

Manufacturing Example 2

<Manufacture of rubber polymers>

Into a nitrogen-purged polymerization reactor (autoclave), 200 parts by weight of ion-exchanged water, 25 parts by weight of styrene, 75 parts by weight of 1,3-butadiene, 3.0 parts by weight of potassium oleate, 3.0 parts by weight of potassium rosinate, 0.1 parts by weight of cumene hydroperoxide, 0.8 parts by weight of t-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of dextrose, and 0.001 parts by weight of iron (II) sulfate were charged all at once, and polymerized at 10°C. When the polymerization conversion rate reached 60%, polymerization was terminated, and a styrene/butadiene rubber polymer latex (gel content: 1 wt%, average particle diameter: 40 nm, refractive index: 1.5350) was manufactured.

<Manufacture of graft polymer>

A mixed solution containing 200 parts by weight of ion-exchanged water, 1.0 parts by weight of sodium oleate, 25.7 parts by weight of methyl methacrylate, 21.8 parts by weight of styrene, 2.5 parts by weight of acrylonitrile, 0.4 parts by weight of t-dodecyl mercaptan, 0.050 parts by weight of ethylenediaminetetraacetic acid, 0.100 parts by weight of sodium formaldehyde sulfoxylate, 0.001 parts by weight of iron (II) sulfate, and 0.2 parts by weight of cumene hydroperoxide was prepared.

50 parts by weight (based on solid content) of the styrene/butadiene rubber polymer latex was introduced into the reactor. Thereafter, the mixed solution was continuously introduced into the reactor at 60°C for 5 hours to polymerize. After the continuous introduction of the mixed solution was completed, the mixture was aged at 60°C for 1 hour to complete the polymerization, thereby producing a graft polymer latex. The entire amount of the prepared graft polymer latex was introduced into an aqueous solution containing 2 parts by weight of calcium chloride, coagulated, aged, washed, dehydrated, and dried to produce a graft polymer powder (refractive index: 1.5350).

Manufacturing Example 3

<Manufacture of rubber polymers>

Into a nitrogen-purged polymerization reactor (autoclave), 200 parts by weight of ion-exchanged water, 25 parts by weight of styrene, 75 parts by weight of 1,3-butadiene, 3.0 parts by weight of potassium oleate, 3.0 parts by weight of potassium rosinate, 0.1 parts by weight of cumene hydroperoxide, 1.0 parts by weight of t-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of dextrose, and 0.001 parts by weight of iron (II) sulfate were charged all at once, and polymerized at 15°C. When the polymerization conversion rate reached 60%, polymerization was terminated, and a styrene/butadiene rubber polymer latex (gel content: 5 wt%, average particle size: 40 nm, refractive index: 1.5350) was manufactured.

<Manufacture of graft polymer>

A graft polymer powder (refractive index: 1.5350) was prepared in the same manner as in Manufacturing Example 2, except that the styrene/butadiene rubber polymer latex described above was used.

Manufacturing Example 4

<Manufacture of rubber polymers>

Into a nitrogen-substituted polymerization reactor (autoclave), 200 parts by weight of ion-exchanged water, 25 parts by weight of styrene, 75 parts by weight of 1,3-butadiene, 2.0 parts by weight of potassium oleate, 3.0 parts by weight of potassium rosinate, 0.1 part by weight of potassium persulfate, 0.8 parts by weight of t-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of dextrose, and 0.001 parts by weight of iron (II) sulfate were charged all at once, and polymerized at 10°C. When the polymerization conversion rate reached 65%, the polymerization was terminated, and a styrene/butadiene rubber polymer latex (gel content: 15 wt%, average particle diameter: 40 nm, refractive index: 1.5350) was manufactured.

<Manufacture of graft polymer>

A graft polymer powder (refractive index: 1.5350) was prepared in the same manner as in Manufacturing Example 2, except that the styrene/butadiene rubber polymer latex described above was used.

Manufacturing Example 5

<Manufacture of rubber polymers>

Into a nitrogen-purged polymerization reactor (autoclave), 200 parts by weight of ion-exchanged water, 25 parts by weight of styrene, 75 parts by weight of 1,3-butadiene, 1.0 parts by weight of potassium oleate, 1.0 parts by weight of potassium rosinate, 0.2 parts by weight of potassium persulfate, 0.3 parts by weight of t-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of dextrose, and 0.001 parts by weight of iron (Ⅱ) sulfate were charged all at once, and polymerized at 70°C. When the polymerization conversion rate reached 93%, the polymerization was terminated, and a styrene/butadiene rubber polymer latex (gel content: 65 wt%, average particle size: 300 nm, refractive index: 1.5350) was manufactured.

<Manufacture of graft polymer>

A graft polymer powder (refractive index: 1.5350) was prepared in the same manner as in Manufacturing Example 2, except that the styrene/butadiene rubber polymer latex described above was used.

Manufacturing Example 6

<Manufacture of rubber polymers>

Into a nitrogen-substituted polymerization reactor (autoclave), 200 parts by weight of ion-exchanged water, 25 parts by weight of styrene, 75 parts by weight of 1,3-butadiene, 2.0 parts by weight of potassium oleate, 1.0 parts by weight of potassium rosinate, 0.3 parts by weight of potassium persulfate, 0.3 parts by weight of t-dodecyl mercaptan, 0.010 parts by weight of sodium pyrophosphate, 0.050 parts by weight of dextrose, and 0.001 parts by weight of iron (II) sulfate were charged all at once, and polymerized at 70°C. When the polymerization conversion rate reached 99%, the polymerization was terminated, and a styrene/butadiene rubber polymer latex (gel content: 90 wt%, average particle diameter: 90 nm, refractive index: 1.5350) was manufactured.

<Manufacture of graft polymer>

A graft polymer powder (refractive index: 1.5350) was prepared in the same manner as in Manufacturing Example 2, except that the styrene/butadiene rubber polymer latex described above was used.

Manufacturing Example 7

Methyl methacrylate homopolymer (IH830 from LG MMA, refractive index: 1.4900) was used.

Manufacturing Example 8

A mixed solution containing 86 parts by weight of methyl methacrylate, 14 parts by weight of styrene, 3 parts by weight of toluene, 0.01 parts by weight of 1,1-bis(t-butylperoxy)cyclohexane, and 0.4 parts by weight of t-dodecyl mercaptan was prepared.

The above mixed solution was continuously fed into the reactor for polymerization so that the average polymerization time was 3 hours. At this time, the temperature of the reactor was 148°C. The polymer solution discharged from the reactor was heated in a preheating tank, and unreacted monomers were volatilized in a volatilization tank to produce a polymer. Then, while maintaining the temperature of the polymer at 210°C, it was transferred to a polymer transfer pump extrusion processing machine, thereby producing non-grafted polymer pellets (refractive index: 1.5040).

Examples 1 to 4, Comparative Examples 1 to 4

A thermoplastic resin composition was prepared by mixing the graft polymer and non-graft polymer of the manufacturing example in the amounts described in Tables 1 and 2 below.

Experimental Example 1

The properties of the rubber polymer of the manufacturing example were evaluated by the method described below, and the results are shown in Tables 1 and 2 below.

1) Gel content (% by weight): After coagulating the rubber polymer latex with calcium chloride, it was washed and dried in a vacuum oven at 60°C for 24 hours to obtain a rubber lump. This rubber lump was cut into small pieces with scissors to prepare a 1-g rubber section, which was placed in 100 g of toluene and stored in a dark room at 23°C for 48 hours, after which the sol and gel were separated. The sol and gel were substituted into the following equation to calculate the gel content.

Gel content (wt%) = weight of gel / weight of rubber section × 100

2) Average particle size (nm): Measured using the dynamic light scattering method with Nicomp 380 equipment from Particle Sizing Systems.

3) Refractive index: The rubber section manufactured when measuring gel content was cut into 0.2 mm thick and measured using an Abbe refractometer using visible light with a wavelength of 589.3 nm at 25°C.

Experimental Example 2

The composition of the thermoplastic resin compositions of the examples and comparative examples was measured by the method described below, and the results are shown in Tables 1 and 2 below.

1) Content (weight %) of styrene/butadiene rubbery polymer, methyl methacrylate monomer unit, styrene monomer unit, and acrylonitrile monomer unit: The contents of rubbery polymer and monomer units in the thermoplastic resin composition were derived by infrared spectroscopy using a Nicolet ^TM iS20 FTIR Spectrometer (model name, manufacturer: Thermo Scientific).

Experimental Example 3

100 parts by weight of the thermoplastic resin compositions of Examples and Comparative Examples and 0.2 parts by weight of an antioxidant were mixed and extruded to produce pellets. The pellets were injection-molded to produce specimens, and their physical properties were evaluated using the methods described below. The results are shown in Tables 1 and 2 below.

1) Gloss (45°): The gloss of the specimen (thickness: 3 mm) was measured at 45° using a gloss meter VG7000 from Nippon Denshoku. When the gloss value was 30 or less, the matte characteristic was considered to be achieved, and the lower the gloss value, the better the matte characteristic.

2) Gloss (60°): The gloss of the specimen (thickness: 3 mm) was measured at 60° using a gloss meter VG7000 from Nippon Denshoku. When the gloss value was 30 or less, the matte characteristic was considered to be achieved, and the lower the gloss value, the better the matte characteristic.

3) Impact strength (kgf·cm/cm): The notched Izod impact strength of the specimen (1/4 inch) was measured at 23 ℃ according to ASTM D256.

4) Pencil hardness: Measured according to ASTM D3365.

division Example 1 Example 2 Example 3 Example 4 graft polymer type Manufacturing Example 1 Manufacturing Example 2 Manufacturing Example 2 Manufacturing Example 3 SBR monomer
(weight%) S 20 25 25 25 BD 80 75 75 75 Gel content (wt%) 0 1 1 5 Average particle size (nm) 40 40 40 40 refractive index 1.5310 1.5350 1.5350 1.5350 Other than monomers
(weight) SBR 50.0 50.0 50.0 50.0 MMA 29.6 25.7 25.7 25.7 S 20.4 21.8 21.8 21.8 AN 0 2.5 2.5 2.5 refractive index 1.5310 1.5350 1.5350 1.5350 non-graft polymer type Manufacturing Example 5 Manufacturing Example 5 Manufacturing Example 5 Manufacturing Example 5 refractive index 1.4900 1.4900 1.4900 1.4900 thermoplastic resin composition Graft polymer (by weight) 30 20 30 30 Non-graft polymer (by weight) 70 80 70 70 SBR (weight%) 15 10 15 15 MMA monomer unit (weight%) 78.88 85.14 77.71 77.71 S monomer unit (weight%) 6.12 4.36 6.54 6.54 AN monomer unit (weight%) 0.0 0.5 0.75 0.75 Difference in refractive index between grafted and non-grafted polymers 0.0410 0.0450 0.0450 0.0450 Gloss (45°) 14 13 15 17 Gloss (60 °) 15 14 16 18 Impact strength (kgf·cm/cm) 9 8 11 12 Pencil hardness 2H 3H 2H 28 SBR: styrene/butadiene rubber polymer
S: Styrene
BD: 1,3-butadiene
MMA: Methyl methacrylate
AN: Acrylonitrile

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 graft polymer type Manufacturing Example 4 Manufacturing Example 5 Manufacturing Example 6 Manufacturing Example 3 SBR monomer
(weight%) S 25 25 25 25 BD 75 75 75 75 Gel content (wt%) 15 65 90 5 Average particle size (nm) 40 300 90 40 refractive index 1.5350 1.5350 1.5350 1.5310 Other than monomers
(weight) SBR 50.0 50.0 50.0 50.0 MMA 25.7 25.7 25.7 25.7 S 21.8 21.8 21.8 21.8 AN 2.5 2.5 2.5 2.5 refractive index 1.5350 1.5350 1.5350 1.5350 non-graft polymer type Manufacturing Example 7 Manufacturing Example 7 Manufacturing Example 7 Manufacturing Example 8 monomer
(weight) MMA 100 100 100 86 S 0 0 0 14 refractive index 1.4900 1.4900 1.4900 1.5040 thermoplastic resin composition Graft polymer (by weight) 30 30 30 35 Non-graft polymer (by weight) 70 70 70 65 SBR (weight%) 15 15 15 17.5 MMA monomer unit (weight%) 77.74 77.71 77.71 60.8 S monomer unit (weight%) 6.54 6.54 6.54 21.7 AN monomer unit (weight%) 0.75 0.75 0.75 0.75 Difference in refractive index between grafted and non-grafted polymers 0.0450 0.0450 0.0450 0.0310 Gloss (45°) 49 119 125 18 Gloss (60 °) 51 125 131 19 Impact strength (kgf·cm/cm) 11 11 4 11 Pencil hardness H H 2H HB SBR: styrene/butadiene rubber polymer
S: Styrene
BD: 1,3-butadiene
MMA: Methyl methacrylate
AN: Acrylonitrile

Referring to Tables 1 and 2 above, Examples 1 to 4, which include graft polymers having a gel content of 0 to 5 wt% of the rubber polymer and an average particle size of 40 nm, implemented matte characteristics while also implementing excellent impact resistance and scratch resistance. However, Comparative Example 1, which includes graft polymers having a gel content of 15 wt% of the rubber polymer and an average particle size of 40 nm, failed to implement matte characteristics.

In addition, Comparative Example 2, which included a graft polymer having a gel content of 65 wt% of the rubber polymer and an average particle size of 300 nm of the rubber polymer, failed to achieve matte properties and exhibited reduced scratch resistance. In addition, although Comparative Example 2 had a significantly larger average particle size of the rubber polymer than Examples 1 to 4, the impact resistance was at an equivalent level.

In addition, Comparative Example 3, which includes a graft polymer having a gel content of 90 wt% of the rubber polymer and an average particle size of 90 nm of the rubber polymer, failed to achieve matte properties. In addition, although Comparative Example 3 had a significantly larger average particle size of the rubber polymer compared to Examples 1 to 4, the impact resistance was reduced.

In addition, Comparative Example 4, which includes a non-graft polymer containing less than 90 wt% of methyl methacrylate monomer units, had a pencil hardness of HB compared to Examples 1 to 4, resulting in lower scratch resistance.

Claims (9)

A graft polymer comprising a rubbery polymer having a gel content of 0 to 10 wt% and including vinyl aromatic monomer units and diene monomer units, and a shell including (meth)acrylate monomer units and vinyl aromatic monomer units grafted onto the rubbery polymer; and
A thermoplastic resin composition comprising a non-graft polymer containing 90 wt% or more of (meth)acrylate monomer units.
In claim 1,
A thermoplastic resin composition wherein the rubber polymer has a gel content of 0 to 5 wt%.
In claim 1,
A thermoplastic resin composition wherein the rubber polymer comprises the vinyl aromatic monomer unit and the diene monomer unit in a weight ratio of 10:90 to 35:65.
In claim 1,
A thermoplastic resin composition wherein the above rubber polymer has an average particle diameter of 20 to 100 nm.
In claim 1,
The above graft polymer
30.0 to 65.0 wt% of the above rubber polymer;
10.0 to 55.0 wt% of the above (meth)acrylate monomer unit; and
A thermoplastic resin composition comprising 5.0 to 40.0 wt% of a vinyl aromatic monomer unit contained in the above shell.
In claim 1,
A thermoplastic resin composition wherein the non-graft polymer comprises at least one selected from the group consisting of (meth)acrylic acid monomer units and vinyl aromatic monomer units.
In claim 1,
The above thermoplastic resin composition
10.0 to 50.0 wt% of the graft polymer; and
A thermoplastic resin composition comprising 50.0 to 90.0 wt% of the above non-graft polymer.
In claim 1,
A thermoplastic resin composition wherein the shell of the graft polymer comprises a vinyl cyanide monomer unit grafted onto the rubbery polymer.
In claim 1,
The above thermoplastic resin composition
5.0 to 25.0 wt% of the above rubber polymer;
60.0 to 90.0 wt% of the above (meth)acrylate monomer unit; and
A thermoplastic resin composition comprising 3.0 to 20.0 wt% of a vinyl aromatic monomer unit contained in the shell of the graft polymer and the non-graft polymer.