WO2019221448A1 - Matrix copolymer, graft copolymer, and thermoplastic resin composition - Google Patents

Abstract

The present invention relates to: a matrix copolymer comprising a cellulose nanocrystal derivative, an alkyl (meth)acrylate-based monomer unit, an aromatic vinyl-based monomer unit, and a vinyl cyanide-based unit; a graft copolymer comprising a cellulose nanocrystal derivative, a conjugated diene polymer, an alkyl (meth)acrylate-based monomer unit, an aromatic vinyl-based monomer unit, and a vinyl cyanide-based unit; and a thermoplastic resin composition comprising at least one of the copolymers. According to the present invention, provided can be a thermoplastic resin composition having improved processability, impact strength, tensile strength, and chemical resistance while maintaining transparency.

Description

 Matrix Copolymer, Graft Copolymer and Thermoplastic Resin Composition

[Citations with Related Applications]

The present invention relates to Korean patent applications Nos. 10-2018-0054988, 10-2018-0054989 and 10-2018-0054990, filed May 14, 2018, and Korea, filed May 14, 2019. Claims the benefit of priority based on patent application No. 10-2019-0055975 and includes all contents disclosed in the literature of that Korean patent application as part of this specification.

[Technical Field]

The present invention relates to a matrix copolymer, a graft copolymer and a thermoplastic resin composition, and to a matrix copolymer, a graft copolymer and a thermoplastic resin composition comprising a cellulose nanocrystal derivative.

The transparent thermoplastic resin composition is prepared by extruding the transparent graft copolymer and the transparent matrix copolymer. As the refractive index of the transparent graft copolymer and the transparent matrix copolymer coincides, the transparency of the thermoplastic resin molded article is improved.

Meanwhile, the transparent matrix copolymer and the transparent graft copolymer include methyl methacrylate units having a low refractive index as the highest content among the components. These methyl methacrylate units improve the transparency of the transparent matrix copolymer, but lower the chemical resistance. In addition, the methyl methacrylate unit may be pyrolyzed at a high temperature of 300 ° C. or higher, thereby reducing the color or thermal stability of the final product.

Accordingly, studies for producing a transparent matrix copolymer and a transparent graft copolymer excellent in both transparency and chemical resistance are continuing.

An object of the present invention is to provide a matrix copolymer, a graft copolymer and a thermoplastic resin composition excellent in transparency, chemical resistance and mechanical properties.

The present invention is a cellulose nanocrystal derivative; Alkyl (meth) acrylate monomer units; Aromatic vinyl monomer units; And it provides a matrix copolymer comprising a vinyl cyan monomer unit.

The present invention also provides a method for producing a matrix copolymer in which a cellulose nanocrystal, an alkyl (meth) acrylate monomer, an aromatic vinyl monomer, and a vinyl cyan monomer are added to a reactor and polymerized.

In addition, the present invention is a cellulose nanocrystal derivative; Conjugated diene-based polymers; Alkyl (meth) acrylate monomer units; Aromatic vinyl monomer units; And it provides a graft copolymer comprising a vinyl cyan monomer unit.

The present invention also provides a method for preparing a graft copolymer in which cellulose nanocrystals, conjugated diene polymers, alkyl (meth) acrylate monomers, aromatic vinyl monomers and vinyl cyan monomers are added to a reactor and graft polymerized. do.

The present invention also provides a matrix copolymer comprising an alkyl (meth) acrylate monomer unit, an aromatic vinyl monomer unit, and a vinyl cyan monomer unit; And a graft copolymer comprising a conjugated diene polymer, an alkyl (meth) acrylate monomer unit, an aromatic vinyl monomer unit, and a vinyl cyan monomer unit, wherein the matrix copolymer and the graph At least one or more of the copolymer copolymer provides a thermoplastic resin composition further comprises a cellulose nanocrystal derivative.

The matrix copolymer, the graft copolymer, and the thermoplastic resin composition of the present invention can further improve chemical resistance, impact strength, and tensile strength while maintaining transparency at an equivalent level by including cellulose nanocrystal derivatives.

In addition, the cellulose nanocrystal derivative contained in the matrix copolymer and the graft copolymer of the present invention may partially replace the alkyl (meth) acrylate-based monomer units, and therefore, The chemical degradation can be minimized.

In addition, since the low refractive index of the cellulose nanocrystal derivatives included in the matrix copolymer and the graft copolymer of the present invention may include an aromatic vinyl monomer unit in excess than before, workability may be further improved.

Hereinafter, the present invention will be described in more detail to aid in understanding the present invention.

The terms or words used in this specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best describe their invention. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

Cellulose nanocrystal (C ellulose N ano C rystal, CNC) in the present invention can be obtained by chemical treatment of cellulose. The cellulose may be composed of a crystalline region and an amorphous region. When acid is added to the cellulose, hydronium ions (H ₃ O ⁺ ) penetrate into the amorphous region where molecules are arranged relatively irregularly, and the penetrated hydronium ions are glyco Hydrolysis of the seed bonds may be promoted to prepare cellulose nanocrystals in which amorphous regions are converted to crystalline regions. Here, the acid may be at least one selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid and nitric acid, of which sulfuric acid is preferred.

In the present invention, the cellulose nanocrystals may have a refractive index of 1.4 to 1.5 or 1.42 to 1.48, of which 1.42 to 1.48 is preferable. If the above range is satisfied, the transparency of the copolymer can be maintained at an equivalent level as before.

In the present invention, the cellulose nanocrystals may be secondary particles including a plurality of primary particles. Here, the primary particles may refer to a single crystal of cellulose nanocrystals, and the secondary particles may refer to a collection of primary particles that are single crystals of a plurality of cellulose nanocrystals.

The cellulose nanocrystals may have an average diameter of primary particles of 5 to 20 nm or 9 to 14 nm, and preferably 9 to 14 nm. If the above range is satisfied, the chemical resistance and mechanical properties of the matrix copolymer or the graft copolymer can be further improved. The cellulose nanocrystals have an average length of primary particles of 50 to 200 nm or 100 to 150 nm, of which 100 to 150 nm is preferred. If the above range is satisfied, the chemical resistance and mechanical properties of the matrix copolymer or the graft copolymer can be further improved.

Here, the average diameter and average length of primary particles of the cellulose nanocrystal can be measured using a transmission electron microscope (T ransmission E lectron M icroscope, TEM).

The cellulose nanocrystals may have an average diameter of secondary particles of 100 to 200 nm or 125 to 175 nm, of which 125 to 175 nm is preferable. If the above range is satisfied, the chemical resistance, impact resistance and tensile strength of the matrix copolymer or the graft copolymer can be further improved.

Here, the average particle diameter of the secondary particles of the cellulose nanocrystals may mean an average hydrodynamic diameter. 2 average particle diameter of the primary ipcha of the cellulose nanocrystal can be measured by dynamic light scattering (D ynamic L ight S cattering, DLS) method, specifically Zetasizer model Nano-Zs (trade name, manufacturer: Malvern) to be measured by using a Can be.

The cellulose nanocrystals may have a crystallization index of 70% to 90% or 75% to 85%, preferably 75% to 85%. If the above range is satisfied, the cellulose nanocrystals can be more uniformly dispersed when introduced into the polymerization solution.

Here, the crystallinity index (Crystallinity Index) of the cellulose nanocrystals can be measured by the Segal method.

The cellulose nanocrystals may be added during the manufacturing process in the form of a mixed solution with an aqueous solvent in order to uniformly dispersed in the polymerization solution, when the matrix copolymer or graft copolymer is prepared.

The weight ratio of the cellulose nanocrystals and the aqueous solvent may be 5:95 to 15:85 or 5:95 to 10:90, of which 5:95 to 10:90 is preferable. If the above range is satisfied, the cellulose nanocrystals can be more uniformly dispersed in the polymerization solution.

The aqueous solvent may be water, with reverse osmosis water being preferred.

The zeta potential of the cellulose nanocrystals in the solution may be -45 kV to -25 kV or -40 kV to -30 kV, of which -40 kV to -30 kV is preferable. If the above conditions are satisfied, the dispersion stability of the cellulose nanocrystal solution may be more excellent. In addition, when the cellulose nanocrystal solution is added to the polymerization solution, it can be more uniformly dispersed.

Here, the zeta potential of the cellulose nanocrystals may be measured by a DLS method using a Zetasizer model Nano-Zs (trade name, manufacturer: Malvern).

In the present invention, the cellulose nanocrystals may be directly manufactured or commercially available, and commercially available materials may be BGB Ultra ^™ Cellulose Nanocrystals Suspension of Blue Goose Biorefineries Inc ..

In the present invention, the refractive index means the absolute refractive index of the material, and the refractive index may be recognized as the ratio of the speed of electromagnetic radiation in free space to the speed of radiation in the material, wherein the radiation has visible wavelengths of 450 nm to 680 nm. It may be a line, specifically visible light of 589.3 nm wavelength. The refractive index can be measured using a known method, that is, using an Abbe Refractometer.

In the present invention, the weight average molecular weight of the matrix copolymer may be measured as a relative value with respect to a standard polystyrene (PS) sample using tetrahydrofuran (THF) and gel permeation chromatography (GPC, water breeze).

In the present invention, the graft ratio of the graft copolymer is a certain amount of the graft copolymer in acetone and vibrated for 24 hours to dissolve the free graft copolymer, centrifuged for 1 hour by centrifugation to separate the supernatant (sol). After that, the precipitate (gel) is vacuum dried at 140 ° C. for 2 hours to obtain an insoluble content, and then it can be calculated using the following formula.

Graft Rate (%) = [(Y- (X × R)) / (X × R)] × 100

X: weight of the graft copolymer added to obtain an insoluble content

Y: insoluble weight

R: Fraction of butadiene rubbery polymer in the graft copolymer added to obtain an insoluble content

In the present invention, the weight average molecular weight (g / mol) of the shell of the graft copolymer is obtained by drying the sol separated by the method described in the graft rate measurement method in a 50 ° C. hot air oven, and then dissolving the sol portion in a THF solution. 0.1% by weight), which can be sieved through a 0.1 μm filter and finally obtain a weight average molecular weight using a GPC device (manufacturer: waters).

In the present invention, the conjugated diene-based polymer may be a conjugated diene-based rubbery polymer, and may be prepared by polymerizing, preferably emulsion-polymerizing, the conjugated diene-based monomer. The conjugated diene monomer may be at least one selected from the group consisting of 1,3-butadiene, isoprene, chloroprene and piperylene, and 1,3-butadiene is preferable.

In the present invention, the alkyl (meth) acrylate monomer unit may be a unit derived from an alkyl (meth) acrylate monomer. The alkyl (meth) acrylate monomers are methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate and lauryl It may be one or more selected from the group consisting of (meth) acrylates, of which methyl methacrylate is preferred.

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

In the present invention, the vinyl cyan monomer unit may be a unit derived from a vinyl cyan monomer. The vinyl cyan-based monomer may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, phenylacrylonitrile, and α-chloroacrylonitrile, of which acrylonitrile is preferable.

1. Matrix Copolymer

Matrix copolymer according to an embodiment of the present invention 1) cellulose nanocrystal derivative; 2) alkyl (meth) acrylate monomer units; 3) aromatic vinyl monomer units; And 4) vinyl cyan monomer units.

On the other hand, the matrix copolymer according to an embodiment of the present invention may have a refractive index of 1.51 to 1.52 or 1.512 to 1.518, of which 1.512 to 1.518 is preferable. When the above range is satisfied, the graft copolymer including the conjugated diene polymer, the alkyl (meth) acrylate monomer unit, the aromatic vinyl monomer unit, and the vinyl cyan monomer unit is matched with the refractive index to form a transparent thermoplastic resin molded article. It can manufacture.

Meanwhile, the matrix copolymer according to an embodiment of the present invention may have a weight average molecular weight of 80,000 to 150,000 g / mol or 90,000 to 120,000 g / mol, of which 90,000 to 120,000 g / mol is preferable. If the above range is satisfied, mechanical properties, particularly impact strength, can be improved.

Hereinafter, the components of the matrix copolymer according to an embodiment of the present invention will be described in detail.

1) Cellulose Nanocrystal Derivative

The cellulose nanocrystal derivative may be changed by reacting the cellulose nanocrystal with one or more selected from the group consisting of alkyl (meth) acrylate monomers, aromatic vinyl monomers and vinyl cyan monomers introduced in the preparation of the matrix copolymer. .

The cellulose nanocrystal derivative can further improve the chemical resistance, impact resistance and tensile strength of the copolymer without affecting the transparency of the matrix copolymer.

Since the cellulose nanocrystal derivative may partially replace the alkyl (meth) acrylate-based monomer unit, it is possible to minimize the decrease in chemical resistance of the copolymer due to the alkyl (meth) acrylate monomer unit.

In addition, since the cellulose nanocrystal derivative having a relatively low refractive index can maintain the transparency of the matrix copolymer, and the matrix copolymer can contain an aromatic vinyl monomer unit in a higher content than before, the processability is equivalent to that of the conventional. I can keep it.

The matrix copolymer may include the cellulose nanocrystal derivative and an alkyl (meth) acrylate monomer unit in a weight ratio of 1:99 to 20:80, 2:98 to 15:85, or 2:98 to 12:88. Among them, it is preferable to include in a weight ratio of 2:98 to 12:88. When the above range is satisfied, the cellulose nanocrystal derivative may partially replace the alkyl (meth) acrylate monomer unit within a range that does not affect the transparency of the copolymer. As a result, a decrease in chemical resistance caused by the alkyl (meth) acrylate monomer unit may be minimized.

The matrix copolymer may include the cellulose nanocrystal derivative and the aromatic vinyl monomer unit in a weight ratio of 5:95 to 35:65, 7:93 to 30:70 or 7:93 to 25:75, of which It is preferably included in the weight ratio of 7:93 to 25:75. When the above range is satisfied, the processability of the matrix copolymer can be further improved while preventing the decrease in transparency of the copolymer due to the cellulose nanocrystal derivative having a low refractive index.

The cellulose nanocrystal derivative may be included in an amount of 0.1 to 15% by weight, 1 to 12% by weight, or 2 to 9% by weight, based on the total weight of the matrix copolymer, 2 to 9% by weight of the matrix copolymer. desirable. When the above-mentioned range is satisfied, chemical resistance and mechanical properties can be further improved without affecting the transparency of the matrix copolymer.

2) Alkyl (meth) acrylate monomer units

The alkyl (meth) acrylate-based monomer units can impart excellent transparency to the matrix copolymer.

The alkyl (meth) acrylate monomer unit may be included in 50 to 75% by weight, 52 to 72% by weight, or 55 to 70% by weight, based on the total weight of the matrix copolymer, 55 to 70% by weight of It is preferably included in%. If the above range is satisfied, the transparency of the copolymer can be further improved.

3) aromatic vinyl monomer unit

The aromatic vinyl monomer unit can impart excellent processability, rigidity and impact resistance to the matrix copolymer.

The aromatic vinyl monomer unit may be included in an amount of 15 to 35% by weight, 17 to 32% by weight, or 20 to 30% by weight, based on the total weight of the matrix copolymer. It is preferable. If the above-mentioned range is satisfied, the rigidity, impact resistance and workability of the copolymer can be further improved.

4) Vinyl Cyanide Monomer Unit

The vinyl cyan monomer unit may impart excellent chemical resistance to the matrix copolymer.

The vinyl cyan monomer unit may be included in an amount of 1 to 15% by weight, 3 to 12% by weight, or 5 to 10% by weight, based on 5 to 10% by weight, based on the total weight of the matrix copolymer. It is preferable. If the above range is satisfied, the chemical resistance of the matrix copolymer can be further improved.

2. Manufacturing method of matrix copolymer

The matrix copolymer according to an embodiment of the present invention is prepared by adding a cellulose nanocrystal, an alkyl (meth) acrylate monomer, an aromatic vinyl monomer, and a vinyl cyan monomer to a reactor and polymerizing the same.

The cellulose nanocrystals may be added during the manufacturing process of the graft copolymer in the form of a solution mixed with a solvent in order to be uniformly dispersed in the polymerization solution.

In the method for preparing the matrix copolymer, the weight ratio of the cellulose nanocrystal and the alkyl (meth) acrylate monomer may be 1:99 to 20:80, 2:98 to 15:85, or 2:98 to 12:88. Of these, it is preferable that they are 2: 98-12: 88. When the above range is satisfied, the cellulose nanocrystals may partially replace the alkyl (meth) acrylate monomers within a range that does not affect the transparency of the matrix copolymer. Accordingly, the content of the alkyl (meth) acrylate-based monomer units in the matrix copolymer can be reduced, thereby minimizing chemical resistance degradation.

In the method for preparing the matrix copolymer, the weight ratio of the cellulose nanocrystal and the aromatic vinyl monomer may be 5:95 to 35:65, 7:93 to 30:70, or 7:93 to 25:75, of which 7 It is preferable that they are: 93-25: 75. When the above range is satisfied, the processability of the matrix copolymer can be further improved while preventing the decrease in transparency of the matrix copolymer due to the cellulose nanocrystals having a low refractive index.

The cellulose nanocrystals are 0.1 to 15% by weight, 1 to 12% by weight, or 2 to 9, based on the total weight of the cellulose nanocrystals, alkyl (meth) acrylate monomers, aromatic vinyl monomers and vinyl cyan monomers. It may be added in the weight%, of which it is preferred to add 2 to 9% by weight. When the above-mentioned range is satisfied, chemical resistance and mechanical properties can be further improved without affecting the transparency of the matrix copolymer.

The alkyl (meth) acrylate monomer is 50 to 75% by weight, 52 to 72% by weight relative to the total weight of the cellulose nanocrystal, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer Or 55 to 70% by weight, of which 55 to 70% by weight is preferred. If the above range is satisfied, the transparency of the copolymer can be further improved.

The aromatic vinyl monomer is 15 to 35% by weight, 17 to 32% by weight or 20 to 30, based on the total weight of the cellulose nanocrystal, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer. It may be by weight, preferably 20 to 30% by weight. When the above range is satisfied, the stiffness, impact resistance and workability of the matrix copolymer can be further improved.

The vinyl cyan monomer is 1 to 15% by weight, 3 to 12% by weight, or 5 to 5, based on the total weight of the cellulose nanocrystal, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer. It may be 10% by weight, of which 5 to 10% by weight is preferred. If the above range is satisfied, the chemical resistance of the matrix copolymer can be further improved.

In addition, the description of the cellulose nanocrystals, alkyl (meth) acrylate monomers, aromatic vinyl monomers and vinyl cyan monomers, the cellulose nanocrystal derivatives, alkyl (meth) acrylate monomer units, aromatic vinyl monomer units And the vinyl cyan monomer unit.

On the other hand, the method for producing a matrix copolymer according to another embodiment of the present invention comprises the steps of polymerizing by adding an alkyl (meth) acrylate monomer, an aromatic vinyl monomer and a vinyl cyan monomer to the reactor (step 1); And it may include the step of adding the cellulose nanocrystals to the reactor and reacting (step 2).

Hereinafter, the steps 1 and 2 will be described in detail.

1) Step 1

Step 1 may be a step of adding an alkyl (meth) acrylate monomer, an aromatic vinyl monomer and a vinyl cyan monomer to the reactor and polymerization.

The polymerization may be a bulk polymerization or a suspension polymerization, of which a bulk polymerization capable of producing a high purity copolymer is preferable.

In the step 1, the alkyl (meth) acrylate monomer, the aromatic vinyl monomer and the vinyl cyan monomer are preferably polymerized while continuously input at a constant rate.

When the monomers are polymerized while being continuously added, it is easy to remove heat during polymerization and suppress the runaway reaction due to excessive heat generation. In addition, the weight average molecular weight and polymerization conversion of the copolymer can be properly maintained.

The continuous dosing and polymerization may be carried out for 1 to 6 hours or 1.5 to 5 hours, preferably 1.5 to 5 hours. If the above conditions are satisfied, a copolymer having a uniform particle size can be produced and a stable polymerization conversion can be obtained.

The continuous dosing and polymerization may be performed at 100 ° C to 180 ° C or 110 ° C to 170 ° C, preferably at 110 ° C to 170 ° C. In addition, the continuous polymerization and the polymerization is preferably carried out at a constant temperature in order to have a suitable polymerization rate.

In step 1, it is preferable to further add one or more selected from the group consisting of an initiator, a molecular weight regulator and a solvent.

In this case, the initiator, the molecular weight regulator and the solvent is preferably continuously added at a constant rate with the monomers described above. When the initiator and the like are continuously added, a copolymer having a uniform particle size can be prepared while maintaining an appropriate polymerization rate.

The initiator is 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) -2-methylcyclohexane, 1,1-bis (t-butylperoxy)- It may be at least one selected from the group consisting of 3,3,5-trimethylcyclohexane or 2,2-bis (t-butylperoxy) butane, among which 1,1-bis (t-butylperoxy) cyclo Hexane is preferred.

The initiator may be added in an amount of 0.5 to 3 parts by weight or 0.7 to 1.5 parts by weight based on 100 parts by weight of the total of the cellulose nanocrystal, the alkyl (meth) acrylate monomer, the aromatic vinyl monomer, and the vinyl cyan monomer. It is preferable to add 0.7-1.5 weight part among these. If the above range is satisfied, the balance between the polymerization conversion ratio and the weight average molecular weight of the copolymer can be balanced.

The molecular weight modifiers include α-methyl styrene dimer, t-dodecyl mercaptan, n-dodecyl mercaptan, octyl mercaptan, carbon tetrachloride, methylene chloride, methylene bromide, tetraethylthiuram disulfide, dipentamethylene thiuram disulfide and di It may be one or more selected from the group consisting of isopropyl chianthogen disulfide, of which t-dodecyl mercaptan is preferred. The molecular weight modifier may be added in an amount of 0.05 to 0.3 parts by weight or 0.1 to 0.2 parts by weight based on 100 parts by weight of the cellulose nanocrystal, the alkyl (meth) acrylate monomer, the aromatic vinyl monomer, and the vinyl cyan monomer. Of these, 0.1 to 0.2 parts by weight is preferably added. If the above range is satisfied, the polymerization conversion ratio of the copolymer can be further increased.

The solvent may be an inert organic solvent when the copolymer is prepared by bulk polymerization. The solvent may be at least one selected from the group consisting of methyl ethyl ketone, petroleum ether, ethyl benzene, toluene, carbon tetrachloride and chloroform, of which toluene is preferable.

The solvent may be added in an amount of 1 to 50 parts by weight or 10 to 40 parts by weight based on 100 parts by weight of the cellulose nanocrystal, an alkyl (meth) acrylate monomer, an aromatic vinyl monomer, and a vinyl cyan monomer. Of these, it is preferable to be added in 10 to 40 parts by weight. When the above range is satisfied, the viscosity of the polymerization solution is appropriately adjusted so that polymerization can be easily performed.

2) step 2

Subsequently, the cellulose nanocrystals may be added to the reactor and reacted. Specifically, the cellulose nanocrystals may be added at a polymerization conversion rate of 40 to 50% and reacted with the polymer and the unreacted monomer obtained in step 1.

When the cellulose nanocrystals are introduced into the reactor in step 2, the cellulose nanocrystals may be uniformly dispersed in the polymer and unreacted monomers obtained in step 1, and as a result, the cellulose nanocrystal derivatives may be uniformly distributed in the matrix copolymer. Copolymers with excellent transparency, chemical resistance and mechanical properties can all be prepared.

On the other hand, when the cellulose nanocrystals are added together in the step 1, the cellulose nanocrystals may be difficult to uniformly dispersed in the matrix copolymer by cellulose nanocrystals are polymerized due to their properties. However, when the cellulose nanocrystals are introduced in step 2, it is possible to minimize the polymerization of the cellulose nanocrystals, and the cellulose nanocrystals are the alkyl (meth) acrylate monomers, aromatic vinyl monomers, and vinyl cyan. The influence on the copolymerization of the monomers can be minimized.

After the cellulose nanocrystals are added, the cellulose nanocrystals may be reacted with the polymer and the unreacted monomer obtained in step 1 for 1 to 5 hours or 1 to 4 hours, preferably 1 to 4 hours. If the above conditions are satisfied, the cellulose nanocrystals may be uniformly dispersed and present stably.

Step 2 may be performed at a higher temperature than step 1, and specifically, may be performed at a temperature of 1 ° C. to 5 ° C., but is not limited thereto.

After the step 2 is completed, the copolymer may be separated by volatilizing the unreacted monomer and the solvent in the polymerization product produced in the step 2 in a devolatilization tank.

3. Graft Copolymer

Graft copolymer according to another embodiment of the present invention is 1) cellulose nanocrystal derivative; 2) conjugated diene polymer 3) alkyl (meth) acrylate monomer units; 4) aromatic vinyl monomer units; And 5) vinyl cyan-based monomer units.

Meanwhile, the graft copolymer according to another embodiment of the present invention may have a weight average molecular weight of 80,000 to 130,000 g / mol or 90,000 to 120,000 g / mol, of which 90,000 to 120,000 g / mol is preferred. Do. If the above range is satisfied, a better balance between the processability and the mechanical properties of the graft copolymer can be achieved.

On the other hand, the graft copolymer according to another embodiment of the present invention may have a refractive index of 1.51 to 1.52 or 1.512 to 1.518, of which 1.512 to 1.518 is preferable. If the above-mentioned range is satisfied, the graft copolymer excellent in transparency can be manufactured.

Hereinafter, the components of the graft copolymer according to another embodiment of the present invention will be described in detail.

1) Cellulose Nanocrystal Derivative

The cellulose nanocrystal derivative is reacted with at least one selected from the group consisting of conjugated diene polymers, alkyl (meth) acrylate monomers, aromatic vinyl monomers and vinyl cyan monomers in which cellulose nanocrystals are introduced during the preparation of graft copolymers. It may be changed.

 The cellulose nanocrystal derivative can significantly improve the chemical resistance and mechanical properties of the graft copolymer. Since the cellulose nanocrystal derivative may partially replace the alkyl (meth) acrylate-based monomer unit, it is possible to minimize a decrease in chemical resistance of the graft copolymer due to the alkyl (meth) acrylate monomer unit. In addition, the graft copolymer may maintain transparency due to the relatively low refractive index cellulose nanocrystal derivative, and the graft copolymer may include an aromatic vinyl monomer unit in a higher content than the conventional one, and thus processability is equivalent to that of the conventional one. Can be maintained.

The graft copolymer may include the cellulose nanocrystal derivative and an alkyl (meth) acrylate monomer unit in a weight ratio of 1:99 to 30:70, 2:98 to 25:75, or 3:97 to 20:80. Among them, it is preferable to include in a weight ratio of 3:97 to 20:80. When the above range is satisfied, the cellulose nanocrystal derivative may partially replace the alkyl (meth) acrylate monomer unit within a range that does not affect the transparency of the graft copolymer. As a result, a decrease in chemical resistance caused by the alkyl (meth) acrylate monomer unit may be minimized.

The graft copolymer of the cellulose nanocrystal derivative and the aromatic vinyl monomer unit 1:99 to 40:60, 3:97 to 35:65, 5:95 to 30:70 or 8:92 to 25:75 It may be included in a weight ratio, of which it is preferable to include in a weight ratio of 8:92 to 25:75. When the above-mentioned range is satisfied, the workability of the graft copolymer can be further improved while preventing the decrease in transparency of the graft copolymer due to the cellulose nanocrystal derivative having a low refractive index.

The cellulose nanocrystal derivative may be included in an amount of 0.1 to 10% by weight, 0.5 to 8% by weight, or 1 to 5% by weight, based on 1 to 5% by weight, based on the total weight of the graft copolymer. It is preferable. When the above-mentioned range is satisfied, chemical resistance and mechanical properties can be further improved without affecting the transparency of the graft copolymer.

2) conjugated diene polymer

The conjugated diene polymer is a conjugated diene polymer and a conjugated diene polymer and a cellulose nanocrystal that are modified by graft copolymerization of an alkyl (meth) acrylate monomer, an aromatic vinyl monomer, and a vinyl cyan monomer to a conjugated diene polymer. The reaction may include a modified conjugated diene-based polymer.

The conjugated diene-based polymer may have an average particle diameter of 0.05 to 0.5 ㎛ or 0.1 to 0.4 ㎛, of which 0.1 to 0.4 ㎛ is preferred. If the above-mentioned range is satisfied, a graft copolymer excellent in both mechanical properties and surface gloss properties can be produced.

The conjugated diene polymer may be included in an amount of 40 to 60 wt%, 42 to 57 wt%, or 45 to 55 wt% of the conjugated diene polymer based on the total weight of the graft copolymer, of which 45 to 55 wt%. It is preferably included in the weight percent. If the above range is satisfied, the stiffness, mechanical properties, processability and surface gloss properties of the graft copolymer may be further improved.

3) Alkyl (meth) acrylate monomer unit

The alkyl (meth) acrylate-based monomer unit can impart excellent transparency to the graft copolymer.

The alkyl (meth) acrylate monomer unit may be included in the amount of 15 to 40% by weight, 17 to 37% by weight, or 20 to 35% by weight, based on the total weight of the graft copolymer, of which 20 to 35 It is preferably included in the weight percent. If the above range is satisfied, the transparency of the graft copolymer can be further improved.

4) Aromatic vinyl monomer unit

The aromatic vinyl monomer unit can impart the processability, rigidity and mechanical properties of the graft copolymer.

The aromatic vinyl monomer unit may be included in 5 to 20% by weight, 7 to 17% by weight, or 10 to 15% by weight, based on the total weight of the graft copolymer, of which 10 to 15% by weight It is preferred to be included. If the above range is satisfied, the workability, rigidity and mechanical properties of the graft copolymer can be further improved.

5) Vinyl Cyanic Monomer Unit

The vinyl cyan monomer unit may impart excellent chemical resistance to the graft copolymer.

The vinyl cyan monomer unit may be included in an amount of 1 to 15% by weight, 3 to 12% by weight, or 5 to 10% by weight, based on the total weight of the graft copolymer, including 5 to 10% by weight. It is preferable to be. If the above range is satisfied, the chemical resistance of the graft copolymer can be further improved.

4. Manufacturing method of graft copolymer

The graft copolymer according to another embodiment of the present invention is prepared by adding a cellulose nanocrystal, a conjugated diene polymer, an alkyl (meth) acrylate monomer, an aromatic vinyl monomer, and a vinyl cyan monomer to a reactor and polymerizing the same. .

In the method for preparing the graft copolymer, the weight ratio of the cellulose nanocrystal and the alkyl (meth) acrylate monomer may be 1:99 to 30:70, 2:98 to 25:75, or 3:97 to 20:80. Among them, 3:97 to 20:80 are preferable. When the above range is satisfied, the cellulose nanocrystals may partially replace the alkyl (meth) acrylate monomers within a range that does not affect the transparency of the graft copolymer. Thus, it is possible to minimize the decrease in chemical resistance caused by the alkyl (meth) acrylate-based monomers.

In the method for preparing the graft copolymer, the weight ratio of the cellulose nanocrystal and the aromatic vinyl monomer is 1:99 to 40:60, 3:97 to 35:65, 5:95 to 30:70 or 8:92 to 25 : 75, of which 8:92 to 25:75 are preferred. When the above-mentioned range is satisfied, the workability of the graft copolymer can be further improved while preventing the decrease in transparency of the graft copolymer due to the cellulose nanocrystal having a low refractive index.

The cellulose nanocrystals are 0.1 to 10% by weight, 0.5 to 8% by weight based on the total weight of the cellulose nanocrystals, conjugated diene polymer, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer. , Or 1 to 5% by weight, preferably 1 to 5% by weight. When the above-mentioned range is satisfied, chemical resistance and mechanical properties can be further improved without affecting the transparency of the graft copolymer.

The conjugated diene polymer is 40 to 60% by weight of the conjugated diene polymer based on the total weight of the cellulose nanocrystal, conjugated diene polymer, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer. , 42 to 57 wt%, or 45 to 55 wt%, of which 45 to 55 wt% is preferred. If the above range is satisfied, the stiffness, mechanical properties, processability and surface gloss properties of the graft copolymer may be further improved.

The alkyl (meth) acrylate monomer is 15 to 40% by weight, based on the total weight of the cellulose nanocrystal, conjugated diene polymer, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer, 17 to 37% by weight, or 20 to 35% by weight, of which 20 to 35% by weight is preferred. If the above range is satisfied, the transparency of the graft copolymer can be further improved.

The aromatic vinyl monomer is 5 to 20 wt%, 7 to 17 wt% based on the total weight of the cellulose nanocrystal, conjugated diene polymer, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer. %, Or 10 to 15% by weight, of which 10 to 15% by weight is preferred. If the above range is satisfied, the workability, rigidity and mechanical properties of the graft copolymer can be further improved.

The vinyl cyan monomer is 1 to 15% by weight, 3 to 12 weight based on the total weight of the cellulose nanocrystal, conjugated diene polymer, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer. %, Or 5 to 10 weight percent, of which 5 to 10 weight percent is preferred. If the above range is satisfied, the chemical resistance of the graft copolymer can be further improved.

In addition, the description of the cellulose nanocrystals, conjugated diene polymers, alkyl (meth) acrylate monomers, aromatic vinyl monomers and vinyl cyan monomers, the cellulose nanocrystal derivatives, alkyl (meth) acrylate monomer units, It is as having described in description about an aromatic vinyl monomer unit and a vinyl cyan monomer unit.

On the other hand, the graft copolymer production method according to another embodiment of the present invention is a step of polymerizing the conjugated diene polymer, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer in the reactor (Step 1); And it is preferable that the cellulose nanocrystals are prepared by a manufacturing method comprising the step (step 2) of the reaction.

Step 1 may be a step of emulsion polymerization by adding the conjugated diene polymer, alkyl (meth) acrylate monomers, aromatic vinyl monomers and vinyl cyan monomers.

In step 1, the conjugated diene-based polymer is collectively added to the reactor, and then the alkyl (meth) acrylate-based monomer, aromatic vinyl-based monomer and vinyl cyan-based monomer are preferably polymerized while continuously feeding at a constant rate. When the polymerization is carried out by the above-described method, heat removal during polymerization is easy, and congestion reaction due to excessive heat generation can be suppressed.

The continuous dosing and polymerization may be carried out for 3 to 7 hours or 4 to 6 hours, preferably 4 to 6 hours. If the above conditions are satisfied, graft copolymerization can be easily performed as long as it is easy to defrost during polymerization and can suppress the runaway reaction caused by excessive exotherm.

The continuous addition and polymerization may be carried out at 60 ℃ to 80 ℃ or 62 ℃ to 78 ℃, it is preferably carried out at 62 ℃ to 78 ℃. In addition, the continuous dosing and polymerization is preferably carried out at a constant temperature.

Herein, the conjugated diene-based polymer may be in a latex form dispersed in water in a colloidal state.

On the other hand, in step 1, it is preferable to further add one or more selected from the group consisting of an initiator, an emulsifier, a molecular weight regulator, an oxidation-reduction catalyst and ion-exchanged water.

In addition, it is preferable to continuously input at a constant rate with the above-described monomers. When the initiator and the like are continuously added, the polymerization rate can be controlled, and the copolymer having a uniform particle size can be polymerized while suppressing the runaway reaction due to excessive heat generation.

The initiator may be at least one selected from the group consisting of a peroxide initiator and a sulfite initiator.

The peroxide initiator may be at least one selected from the group consisting of t-butyl peroxide, cumene hydroperoxide and diisopropylbenzene peroxide, of which cumene hydroperoxide is preferable. The sulfite-based initiator may be at least one selected from the group consisting of potassium persulfate, sodium persulfate and ammonium persulfate, and potassium persulfate is preferred.

The initiator is 0.01 to 0.1 parts by weight or 0.03 to 0.08 parts by weight based on 100 parts by weight of the conjugated diene polymer, cellulose nanocrystal, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer. It may be added, of which 0.03 to 0.08 parts by weight is preferably added. If the above-mentioned range is satisfied, while the emulsion polymerization is easily performed, the residual amount in the graft copolymer can be minimized.

The emulsifier may be at least one selected from the group consisting of C ₁₂ to C ₁₈ succinate metal salts, sulfonic acid metal salts, alkali metal rosin acids, alkali metal alkali salts and fatty acid dimer alkali metal salts, of which sulfonic acid metal salts are preferred. .

The C ₁₂ to C ₁₈ succinate salt of the alkenyl succinic acid may be di-potassium salt of a C ₁₂ to C _18.

The sulfonic acid metal salt is one selected from the group consisting of sodium dodecyl sulfate, sodium lauric sulfate, sodium octadecyl sulfate, sodium oleic sulfate, potassium dodecyl sulfate, sodium dodecyl benzene sulfonate and potassium octadecyl sulfonate. Or more, of which sodium dodecyl benzene sulfonate is preferred.

The rosin acid alkali metal salt may be one or more selected from the group consisting of potassium rosin acid salt and sodium rosin acid salt, and potassium rosin acid salt is preferable.

The fatty acid alkali metal salt may be a C ₈ to C ₂₀ fatty acid alkali metal salt, alkali metal salt of capric acid, alkali metal salt of lauric acid, alkali metal salt of palmitic acid, alkali metal salt of stearic acid, alkali metal salt and oleic acid and linol More than 1 type chosen from the group which consists of alkali metal salt of a rain acid is more preferable.

The fatty acid dimer alkali metal salt may be a C ₈ to C ₂₀ fatty acid dimer alkali metal salt, preferably a C ₈ to C ₂₀ fatty acid dimer potassium salt, and more preferably an oleic acid dimer potassium salt.

The emulsifier is 0.1 to 3 parts by weight or 0.5 to 2 parts by weight based on 100 parts by weight of the conjugated diene polymer, cellulose nanocrystal, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer. It may be added, of which 0.5 to 2 parts by weight is preferably added. If the above range is satisfied, the polymerization rate may be excellent while maintaining the reaction rate appropriately. In addition, discoloration and gas generation due to the emulsifier can be minimized.

The molecular weight modifier is as described above, t-dodecyl mercaptan is preferred.

The molecular weight modifier is 0.1 to 0.6 parts by weight or 0.2 to 0.5 parts by weight based on 100 parts by weight of the conjugated diene polymer, cellulose nanocrystal, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer. It may be added in a portion, of which 0.2 to 0.5 parts by weight is preferably added. If the above-mentioned range is satisfied, the graft copolymer having the target weight average molecular weight can be produced while the polymerization conversion rate of the shell can be further increased while appropriately adjusting the weight average molecular weight of the shell.

The redox catalyst may be at least one selected from the group consisting of sodium formaldehyde sulfoxylate, ethylenediamine tetraacetic acid disodium salt, ferrous sulfate, dextrose, sodium pyrophosphate, anhydrous sodium pyrophosphate and sodium sulfate. Among them, at least one selected from the group consisting of sodium formaldehyde sulfoxylate, ethylenediamine tetraacetic acid disodium salt and ferrous sulfate is preferable.

The redox catalyst is 0.01 to 0.1 parts by weight or 0.02 to 100 parts by weight of the total of the conjugated diene polymer, cellulose nanocrystal, alkyl (meth) acrylate monomer, aromatic vinyl monomer and vinyl cyan monomer. To 0.09 parts by weight, of which 0.02 to 0.09 parts by weight is preferred. If the above range is satisfied, polymerization can be easily initiated at a relatively low temperature.

Step 2 is a step of ripening the polymer obtained in step 1 and further polymerizing the unreacted monomer, cellulose nanocrystals are added in step 2 may react with the polymer and the unreacted monomer obtained in step 1. .

The time point of the cellulose nanocrystals may be a time when the polymerization conversion rate is 40 to 50%.

When the cellulose nanocrystals are introduced in step 2, the cellulose nanocrystals may be uniformly dispersed in the polymer and unreacted monomers obtained in step 1, and as a result, the cellulose nanocrystal derivatives are uniformly distributed in the graft copolymer, thereby providing transparency, Graft copolymers excellent in both chemical resistance and mechanical properties can be prepared.

On the other hand, the cellulose nanocrystals can be polymerized cellulose nanocrystals due to their properties. However, when the cellulose nanocrystals are introduced in step 2, the cellulose nanocrystals can be minimized from polymerizing, and the cellulose nanocrystals are conjugated diene-based polymers, alkyl (meth) acrylate monomers, and aromatic vinyl-based monomers. The influence on the graft copolymerization of the monomer and the vinyl cyan monomer can also be minimized.

In step 2, the cellulose nanocrystals may be added in batches or continuously.

After the cellulose nanocrystals are added, aging and further polymerization may be performed for 0.5 to 2 hours or 1 to 1.5 hours, and aging and further polymerization is preferably performed for 1 to 1.5 hours. If the above conditions are satisfied, the polymerization conversion rate can be higher.

Step 2 may be carried out at a higher temperature than the step 1, it may be carried out at 75 ℃ to 85 ℃ to 78 ℃ to 83 ℃, which is preferably performed at 78 ℃ to 83 ℃. If the above conditions are satisfied, a copolymer having a uniform particle size can be produced by easily controlling the polymerization temperature and having an appropriate polymerization rate.

When the step 2 is completed, the coagulation, aging, washing and drying may be further performed to obtain a graft copolymer in powder form.

5. Thermoplastic Composition

Thermoplastic resin composition according to another embodiment of the present invention is a matrix copolymer comprising an alkyl (meth) acrylate monomer unit, an aromatic vinyl monomer unit, and a vinyl cyan monomer unit; And a graft copolymer comprising a conjugated diene polymer, an alkyl (meth) acrylate monomer unit, an aromatic vinyl monomer unit, and a vinyl cyan monomer unit, wherein at least one of the matrix copolymer and the graft copolymer At least one further comprises a cellulose nanocrystal derivative.

The weight ratio of the matrix copolymer and the graft copolymer may include a weight ratio of 50:50 to 20:80 or 50:50 to 25:75, and preferably includes a weight ratio of 50:50 to 25:75. . If the above range is satisfied, a thermoplastic resin molded article excellent in transparency, chemical resistance, impact resistance and tensile strength can be produced.

The matrix copolymer and the graft copolymer may have a refractive index difference of 0 to 0.008 or 0 to 0.003, of which 0 to 0.003. If the above-mentioned range is satisfied, the thermoplastic resin molded article excellent in transparency can be manufactured.

The matrix copolymer and the graft copolymer may have a refractive index of 1.51 to 1.52 or 1.512 to 1.518, respectively, of which 1.512 to 1.518 are preferable. When the above range is satisfied, the refractive indexes of the matrix copolymer and the graft copolymer are similar to each other, whereby a transparent thermoplastic resin molded article may be manufactured.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

<Preparation of Aqueous Cellulose Nanocrystals>

BGB Ultra ^™ Cellulose Nanocrystals Suspension from Blue Goose Biorefineries Inc. was used. Information on BGB Ultra ^™ Cellulose Nanocrystals Suspension is as follows.

Refractive index: The cellulose nanocrystal aqueous solution was irradiated with 589.3 nm visible light, and the value measured using the Abbe refractometer was 1.47.

Concentration: 8% w / w

Solvent: Reverse Osmosis Water

Primary particle length: 100-150 nm (Measuring method: TEM)

Particle diameter of primary particles: 9 to 14 nm (Measuring method: TEM)

Diameter of secondary particles: 150 nm (Measuring method: DLS)

<Production of Matrix Copolymer>

Examples 1 to 4, Comparative Example 1

30 parts by weight of toluene in the reactor, 1 part by weight of 1,1-bis (t-butylperoxy) cyclohexane as the initiator, 0.15 part by weight of t-dodecyl mercaptan as the molecular weight regulator, methyl in the amount shown in the following [Table 1] Methacrylate (MMA), styrene (SM) and acrylonitrile (AN) were polymerized with continuous charge at a constant rate for 3 hours. At this time, the polymerization temperature was maintained at 148 ° C. Then, the cellulose nanocrystalline: To (CNC C ellulose N ano C rystal) 2 by weight of cellulose nanocrystalline bulk solution including a commitment, and polymerized for 2 hours, and terminates the polymerization. The obtained polymerization product was heated in a preheating bath and volatilized unreacted monomer and solvent in a volatilization bath. Thereafter, the matrix copolymer in pellet form was prepared by a polymer transfer pump extrusion machine maintained at 210 ° C.

<Production of Graft Copolymer>

Examples 5 to 8, Comparative Example 2

Butadiene rubbery polymer latex (BD, average particle diameter: 300 nm, refractive index: 1.516, gel content: 70%) in a reactor containing 50 parts by weight (based on solids) 1.0 part by weight of sodium dodecyl benzene sulfonate as emulsifier, cumene as initiator 0.04 parts by weight of hydroperoxide, 0.3 parts by weight of t-dodecyl mercaptan as molecular weight modifier, 0.048 parts by weight of sodium formaldehyde sulfoxylate as oxidation-reduction catalyst, 0.012 parts by weight of ethylenediamine tetraacetic acid disodium salt and sulfate 1 Methyl methacrylate (MMA), styrene (SM) and acrylonitrile (AN) at a constant rate at 75 ° C. for 5 hours at 0.001 parts by weight of iron, 100 parts by weight of ion-exchanged water, and the contents described in [Table 2]. The polymerization was carried out while feeding continuously.

Then, after heating the reactor to 80 ℃, cellulose nanocrystal (CNC: C ellulose N ano C rystal) after the cellulose nanocrystalline aqueous solution containing 1 part by weight of a bulk input to the reactor, and was aged for one hour. The reaction was terminated to obtain graft copolymer latex. In this case, the polymerization conversion rate of the graft copolymer latex was 98%.

An aqueous solution of calcium chloride was added to the obtained graft copolymer latex to coagulate, aged, washed and dried to obtain a graft copolymer powder.

<Production of the thermoplastic resin composition>

Example  9 to 22, Comparative example  3

The thermoplastic resin composition was prepared by uniformly mixing the matrix polymer and the graft copolymer described in Table 3 below.

Comparative Example 4

A thermoplastic resin composition was prepared by uniformly mixing an aqueous solution of cellulose nanocrystals including 60 parts by weight of the matrix copolymer of Comparative Example 1, 37 parts by weight of the graft copolymer powder of Comparative Example 2, and 3 parts by weight of cellulose nanocrystals.

Experimental Example 1

The physical properties of the matrix copolymers of Examples and Comparative Examples were evaluated by the methods described below, and the results are shown in the following [Table 1].

① Refractive index: 589.3 nm visible ray was irradiated to the matrix copolymer, and it measured using the Abbe refractometer.

② Polymerization Conversion Rate (%): [(Measured Value TSC) / (Theoretical Value TSC)] × 100

Measured value TSC: solid content of matrix copolymer

Theoretical value TSC: Solid content of monomers and additives theoretically introduced in the preparation of the matrix copolymer

(3) Weight average molecular weight (g / mol): It was measured by using tetrahydrofuran (THF), relative to the standard polystyrene (PS) sample using gel permeation chromatography (GPC, waters breeze).

division		Example 1	Example 2	Example 3	Example 4	Comparative Example 1
Matrix copolymer		A	B	C	D	E
Composition (part by weight)	MMA	66.5	64.0	61.5	59.0	69.0
	SM	24.5	25.0	25.5	24.0	24.0
	AN	7.0	7.0	7.0	7.0	7.0
	CNC	2.0	4.0	6.0	8.0	-
① refractive index		1.516	1.516	1.516	1.516	1.516
② polymerization conversion rate		60	59	61	60	61
③ Weight average molecular weight		109,000	109,500	110,000	115,000	110,000

Referring to Table 1, it can be seen that the matrix copolymers of Examples 1 to 4 have the same refractive index, polymerization conversion ratio, and weight average molecular weight as compared to the matrix copolymer of Comparative Example 1. From these results, it was confirmed that even if the cellulose nanocrystals were added during the manufacturing process of the matrix copolymer, the physical properties of the matrix copolymer were not affected.

Experimental Example 2

The physical properties of the graft copolymer powders of Examples and Comparative Examples were evaluated by the methods described below, and the results are shown in the following [Table 2].

④ Refractive Index: The graft copolymer powder was irradiated with 589.3 nm visible light and measured using an Abbe refractometer.

⑤ Graft rate (%): A certain amount of graft copolymer is added to acetone and vibrated for 24 hours with a vibrator (trade name: SI-600R, manufacturer: Lab. Companion) to dissolve the free graft copolymer, and then centrifuge 14,000. After centrifugation at rpm for 1 hour to separate the supernatant (sol), the precipitate (gel) was dried in a vacuum dryer (trade name: DRV320DB, manufacturer: ADVANTEC) at 140 ° C. for 2 hours to obtain an insoluble content. It can be calculated using an equation.

Graft Rate (%) = [(Y- (X × R)) / (X × R)] × 100

X: weight of the graft copolymer added to obtain an insoluble content

Y: insoluble weight

R: Fraction of butadiene rubbery polymer in the graft copolymer added to obtain an insoluble content

(6) Weight average molecular weight of the shell (g / mol): The sol separated by the method described in the graft rate measurement method was dried in a 50 ° C. hot air oven. Thereafter, the sol portion was dissolved in THF solution to prepare a solution (concentration: 0.1% by weight), which was hung through a 0.1 μm filter, and finally, a weight average molecular weight was obtained using a GPC apparatus (manufacturer: waters). .

division		Example 5	Example 6	Example 7	Example 8	Comparative Example 2
Graft copolymer		A	B	C	D	E
Composition (part by weight)	BD	50.0	50.0	50.0	50.0	50.0
	MMA	31.0	30.0	28.0	24.0	32.0
	SM	11.0	11.2	12.0	12.5	11.0
	AN	7.0	7.0	7.0	7.0	7
	CNC	1.0	1.8	3.0	6.5	-
④ refractive index		1.516	1.516	1.516	1.517	1.516
⑤ graft rate		43.76	44.51	44.50	45.00	43.50
⑥ Weight average molecular weight of shell		110,000	118,960	119,000	119,870	108,900

Referring to Table 2, the graft copolymers of Examples 5 to 8 it was confirmed that the graft copolymer of Comparative Example 2 and the refractive index, the graft ratio and the weight average molecular weight of the shell is the same level or higher. From these results, it was confirmed that the cellulose nanocrystals did not affect the physical properties of the graft copolymer even when the cellulose nanocrystal was added during the manufacturing process of the graft copolymer.

Experimental Example 3

The thermoplastic resin compositions of Examples and Comparative Examples, 2 parts by weight of ethylene bis (stearicamide) and 0.2 parts by weight of phosphate-based antioxidants were uniformly mixed, and then charged into a twin screw extruder set at 230 ° C. to extrude pellets. The flow index of the pellets was measured by the following method, and the results are shown in the following [Table 3] to [Table 6].

⑦ Flow index (g / 10 min): measured under 10 ℃, 220 ℃ in accordance with ASTM D-1238.

Experimental Example 4

The pellets prepared in Experimental Example 3 were injected at 230 ° C., and aged at 25 ° C. and 50 ± 5% relative humidity for 12 hours to prepare specimens. The specimens were evaluated for physical properties by the method described below, and the results are shown in the following [Table 3] to [Table 6].

(8) Transparency (haze,%): The transparency of the sheet having a thickness of 3 mm was measured according to ASTM D-1003.

⑨ Oven change over time (△ E ₁ ): After measuring the L, a, b value of the specimen, and stored the sample in an oven at 80 ℃ for 7 days, the L, a, b value was measured. And the degree of discoloration was evaluated by the following formula.

Where L ₁ ′, a ₁ ′ and b ₁ ′ are L, a and b values measured in a CIE LAB color coordinate system after storing the specimen in an oven at 80 ° C. for 7 days, and L ₁₀ , a ₁₀ and b ₁₀ is the L, a, and b values measured in a CIE LAB color coordinate system before storage in the oven.

류 Injection retention change (ΔE ₂ ): The L, a, b values of the specimens were measured, and after staying at 250 ° C. for 15 minutes in the injection machine, the L, a, b values were measured. And the degree of discoloration was evaluated by the following formula.

Where L ₂ ′, a ₂ ′ and b ₂ ′ are L, a and b values measured with a CIE LAB color coordinate system after the specimen is held at 250 ° C. for 15 minutes in an injection molding machine, and L ₂₀ , a ₂₀ and b ₂₀ is the L, a and b values of the specimen measured in CIE LAB color coordinate system prior to retention.

⑪ Notched Izod impact strength (kg · cm / cm, 1/4 In): Measured according to ASTM D256.

Tensile Strength (kgf / cm 2): Measured according to ASTM D638.

화학 Chemical resistance: After fixing the tensile test specimen in 1.0% jig, isopropyl alcohol solution (concentration: 70%) was applied on the tensile test specimen and the change was visually observed after 10 minutes.

◎: no change, ○: fine crack generation, Δ: crack generation, ×: breakage

division		Example
		9	10	11	12
Matrix copolymer (parts by weight)	Kinds	A	B	C	D
	content	60	60	60	60
Graft copolymer powder (parts by weight)	Kinds	E	E	E	E
	content	40	40	40	40
⑦ Flow index		18.0	17.9	18.2	18.5
⑧ transparency		2.2	2.3	2.4	2.3
⑨Change over oven		3.0	3.1	3.0	3.1
⑩ Change of injection residence		3.2	3.1	3.0	3.8
⑪ impact strength		21.3	23.4	23.1	25.1
⑫ tensile strength		521	535	538	546
화학 chemical resistance		◎	◎	◎	◎

division		Example
		13	14	15
Matrix copolymer (parts by weight)	Kinds	E	E	E
	content	60	60	60
Graft copolymer powder (parts by weight)	Kinds	B	C	D
	content	40	40	40
⑦ Flow index		18.0	18.1	18.5
⑧ transparency		2.0	2.1	2.1
⑨ Change over time		3.2	3.3	3.2
⑩ Change of injection residence		3.4	3.4	3.3
⑪ impact strength		18.0	20.1	23.5
⑫ tensile strength		510	522	555
화학 chemical resistance		○	◎	◎

division		Example
		16	17	18	19
Matrix copolymer (parts by weight)	Kinds	A	B	C	D
	content	60	60	60	60
Graft copolymer powder (parts by weight)	Kinds	A	A	A	A
	content	40	40	40	40
⑦ Flow index		17.9	18.0	18.5	18.6
⑧ transparency		2.1	2.1	2.2	2.3
⑨ Change over time		3.0	3.0	3.1	3.1
⑩ Change of injection residence		3.0	3.2	3.0	3.0
⑪ impact strength		20.5	22.9	23.7	26.8
⑫ tensile strength		528	540	558	575
화학 chemical resistance		◎	◎	◎	◎

division		Example			Comparative example
		20	21	22	3	4
Matrix copolymer (parts by weight)	Kinds	B	B	B	E	E
	content	50	60	60	60	60
Graft copolymer powder (parts by weight)	Kinds	B	B	C	E	E
	content	50	40	40	40	37
CNC (parts by weight)		-	-	-	-	3
⑦ Flow index		18.5	17.9	18.2	-	18.5
⑧ transparency		2.0	2.2	2.2	2	12.0
⑨ Change over time		3.1	3.1	3.1	3.6	-
⑩ Change of injection residence		3.0	3.1	3.0	3.8	-
⑪ impact strength		21.1	23.1	23.3	17.0	19.5
⑫ tensile strength		516	544	551	498	520
화학 chemical resistance		◎	◎	◎	×	◎

Referring to Tables 3 to 6, the specimens of Examples 9 to 12 made of a thermoplastic resin composition comprising a matrix copolymer comprising a cellulose nanocrystal derivative and a graft copolymer not containing a cellulose nanocrystal derivative Flow index and transparency are comparable to those of Comparative Example 3 prepared with a graft copolymer without a cellulose nanocrystal derivative and a thermoplastic resin composition including a matrix copolymer, but changes in oven aging, change in injection flow rate, impact strength, and tensile strength are similar. It was confirmed that the strength and chemical resistance were excellent. In addition, as the content of cellulose nanocrystals added during the preparation of the matrix copolymer increased, changes in oven aging, changes in injection retention, impact strength, tensile strength and chemical resistance were more improved. In addition, cellulose nanocrystal derivatives were included. The specimens of Examples 13 to 15 made of a thermoplastic resin composition comprising a matrix copolymer not containing and a graft copolymer comprising a cellulose nanocrystal derivative are used as the graft copolymer and matrix containing no cellulose nanocrystal derivative. Compared to Comparative Example 3 made of a thermoplastic resin composition including a copolymer, the flow index and transparency were equivalent, but it was confirmed that the change over time, change in injection flow, impact strength, tensile strength, and chemical resistance were excellent. In addition, as the content of the cellulose nanocrystals added during the manufacture of the graft copolymer was increased, changes in oven aging, changes in injection flow, impact strength, tensile strength, and chemical resistance were improved.

In addition, the specimens of Examples 16 to 22 prepared from the graft copolymer including the cellulose nanocrystal derivative and the thermoplastic resin composition including the matrix copolymer include the graft copolymer and the matrix copolymer without the cellulose nanocrystal derivative. Compared to Comparative Example 3 made of a thermoplastic resin composition comprising a flow index and transparency is the same level, it was confirmed that the change over time, the change in injection residence, impact strength, tensile strength and chemical resistance. In addition, as the content of the cellulose nanocrystals added during the preparation of the graft copolymer or the matrix copolymer increased, changes in oven aging, change in injection flow rate, impact strength, tensile strength, and chemical resistance were improved.

On the other hand, in the thermoplastic resin composition of Comparative Example 4 containing the aqueous solution of cellulose nanocrystals as a separate component, it was difficult to continuously perform extrusion because the phenomenon of the cellulose nanocrystals accumulated in the screw of the extruder during the pellet manufacturing process. Therefore, the pellets of Comparative Example 4 could not be extruded to the extent that the change in oven time and injection retention could be measured, and as a result, the change in oven time and injection retention could not be measured. In addition, since the cellulose nanocrystals are present in the form of an aqueous solution, the pellets are carbonized due to water, and the transparency is markedly reduced.

Claims (18)

1. Cellulose nanocrystal derivatives;

   Alkyl (meth) acrylate monomer units;

   Aromatic vinyl monomer units; And

   A matrix copolymer comprising vinyl cyan monomer units.
2. The method according to claim 1,

   The matrix copolymer has a refractive index of 1.51 to 1.52 matrix copolymer.
3. The method according to claim 1,

   The cellulose nanocrystals have a refractive index of 1.4 to 1.5 matrix copolymer.
4. The method according to claim 1,

   The cellulose nanocrystals are secondary particles including a plurality of primary particles,

   The average diameter of the primary particles is 5 to 20 nm, the average length is 50 to 200 nm,

   A matrix copolymer having an average diameter of the secondary particles of 100 to 200 nm in average diameter.
5. A method for producing a matrix copolymer in which a cellulose nanocrystal, an alkyl (meth) acrylate monomer, an aromatic vinyl monomer, and a vinyl cyan monomer are added to a reactor and polymerized.
6. The method according to claim 5,

   The weight ratio of the cellulose nanocrystal and the alkyl (meth) acrylate monomer is 1:99 to 20:80 method of producing a matrix copolymer.
7. The method according to claim 5,

   The weight ratio of the cellulose nanocrystals and the aromatic vinyl monomer is 5:95 to 35:65 method of producing a matrix copolymer.
8. The method according to claim 5,

   For the total weight of the cellulose nanocrystals, alkyl (meth) acrylate monomers, aromatic vinyl monomers and vinyl cyan monomers,

   0.1 to 15% by weight of the cellulose nanocrystals;

   50 to 75 wt% of the alkyl (meth) acrylate monomer;

   15 to 35% by weight of the aromatic vinyl monomer; And

   Method of producing a matrix copolymer of 1 to 15% by weight of the vinyl cyan monomer.
9. Cellulose nanocrystal derivatives;

   Conjugated diene-based polymers;

   Alkyl (meth) acrylate monomer units;

   Aromatic vinyl monomer units; And

   Graft copolymer comprising a vinyl cyan monomer unit.
10. The method according to claim 9,

    The graft copolymer is a graft copolymer having a refractive index of 1.51 to 1.52.
11. The method according to claim 9,

    The cellulose nanocrystal is a graft copolymer having a refractive index of 1.4 to 1.5.
12. The method according to claim 9,

    The cellulose nanocrystals are secondary particles including a plurality of primary particles,

    The average diameter of the primary particles is 5 to 20 nm, the average length is 50 to 200 nm,

    Graft copolymer wherein the average diameter of the secondary particles is 100 to 200 nm in average diameter.
13. A method for producing a graft copolymer in which a cellulose nanocrystal, a conjugated diene polymer, an alkyl (meth) acrylate monomer, an aromatic vinyl monomer, and a vinyl cyan monomer are added to a reactor and graft polymerized.
14. The method according to claim 13,

    The weight ratio of the cellulose nanocrystal and the alkyl (meth) acrylate monomer is 1:99 to 30:70 The method for producing a graft copolymer.
15. The method according to claim 13,

    The weight ratio of the cellulose nanocrystals and the aromatic vinyl monomer is 1:99 to 40:60 The manufacturing method of the graft copolymer.
16. The method according to claim 13,

    For the total weight of the cellulose nanocrystal, conjugated diene polymer, alkyl (meth) acrylate monomer, aromatic vinyl monomer, and vinyl cyan monomer,

    0.1 to 10% by weight of the cellulose nanocrystals;

    40 to 60% by weight of the conjugated diene polymer;

    15 to 40% by weight of the alkyl (meth) acrylate monomers;

    5 to 20% by weight of the aromatic vinyl monomer; And

    1 to 15% by weight of the vinyl cyan monomer.
17. Matrix copolymers comprising alkyl (meth) acrylate monomer units, aromatic vinyl monomer units, and vinyl cyan monomer units; And

    A thermoplastic resin composition comprising a graft copolymer comprising a conjugated diene polymer, an alkyl (meth) acrylate monomer unit, an aromatic vinyl monomer unit, and a vinyl cyan monomer unit,

    At least one or more of the matrix copolymer and the graft copolymer further comprises a cellulose nanocrystal derivative.
18. The method according to claim 17,

    The matrix copolymer and the graft copolymer is a thermoplastic resin composition having a difference in refractive index of 0 to 0.008.