KR20240064169A - Method for preparing non-graft polymer and non-graft polymer prepared by the same - Google Patents

Abstract

The present invention includes the steps of purifying waste containing (meth)acrylate monomers two or more times to produce regenerated (meth)acrylate monomers with a purity of 99.0% by weight or more; and preparing a non-grafted polymer by polymerizing a monomer mixture containing the regenerated (meth)acrylate monomer, vinyl aromatic monomer, and vinyl cyanide monomer. It relates to non-grafted polymers.

Description

Method for producing non-grafted polymers and non-grafted polymers produced thereby {METHOD FOR PREPARING NON-GRAFT POLYMER AND NON-GRAFT POLYMER PREPARED BY THE SAME}

The present invention relates to a method for producing a non-grafted polymer and a non-grafted polymer produced thereby.

Methyl methacrylate is produced by oxidizing isobutylene extracted from C4 residue oil in the gas phase to produce methacrylic acid, and then esterifying it with methanol. This methyl methacrylate is used as a raw material for various plastics.

Meanwhile, when plastic is manufactured using methyl methacrylate recovered from industrial waste such as waste artificial marble and waste acrylic polymer, the color and weather resistance of the plastic are affected because the recovered methyl methacrylate contains various impurities. made poorly. Specifically, methyl methacrylate recovered from waste artificial marble (containing more than 35% by weight of poly(methyl methacrylate)) and waste acrylic polymer contains various impurities due to thermal decomposition, and these impurities affect the color and weather resistance of the plastic. made it worse.

Accordingly, research is needed to manufacture plastics with high purity and excellent product color and weather resistance even when using methyl methacrylate recovered from industrial waste.

KR1022512B

The problem to be solved by the present invention is to provide a non-grafted polymer that achieves the same level of purity, color, and weather resistance as a non-grafted polymer manufactured from a new (meth)acrylate-based monomer, even if it is manufactured from a recycled (meth)acrylate-based monomer. We provide manufacturing methods.

In order to solve the above-described problems, the present invention includes the steps of: 1) purifying waste containing (meth)acrylate-based monomers two or more times to produce recycled (meth)acrylate-based monomers with a purity of 99.0% by weight or more; and preparing a non-grafted polymer by polymerizing a monomer mixture containing the regenerated (meth)acrylate monomer, vinyl aromatic monomer, and vinyl cyanide monomer.

2) The present invention provides a method for producing a non-grafted polymer according to 1) above, wherein the waste is at least one selected from the group consisting of waste artificial marble and waste acrylic polymer.

3) In the present invention, in 1) or 2) above, the step of producing the recycled (meth)acrylate-based monomer includes producing a gas condensate containing the (meth)acrylate-based monomer by pyrolyzing the waste. ; Distilling the gas condensate to prepare a preparation containing a (meth)acrylate-based monomer; Supplying the preparation to a first purification column and performing primary purification to prepare a primary purified product with low boiling point impurities removed compared to the (meth)acrylate monomer; And supplying the first purification to a second purification column and performing secondary purification to remove high boiling point impurities compared to the (meth)acrylate monomer to produce a regenerated (meth)acrylate monomer. A method for producing a phosphorus non-grafted polymer is provided.

4) The present invention provides a method for producing a non-grafted polymer according to 3) above, wherein the thermal decomposition is performed at 400 to 700 ° C.

5) The present invention provides a method for producing a non-grafted polymer according to 3) or 4) above, wherein the primary purification is performed at a temperature 21 to 66° C. lower than the boiling point of the (meth)acrylate monomer.

6) The present invention provides a method for producing a non-grafted polymer according to any one of 3) to 5) above, wherein the primary purification is performed at 100 to 760 torr.

7) The present invention provides a method for producing a non-grafted polymer according to any one of 3) to 6) above, wherein the low boiling point impurities are removed at the top of the first purification column.

8) The present invention provides a method for producing a non-grafted polymer according to any one of 3) to 7) above, wherein the secondary purification is performed at a temperature 11 to 56° C. lower than the boiling point of the (meth)acrylate monomer. to provide.

9) The present invention provides a method for producing a non-grafted polymer according to any one of 3) to 8) above, wherein the secondary purification is performed at 100 to 760 torr.

10) The present invention provides a method for producing a non-grafted polymer according to any one of 3) to 9) above, wherein the high boiling point impurities are removed to the bottom of the second purification column.

11) The present invention provides the method for producing a non-grafted polymer according to any one of 3) to 10) above, wherein a polymerization inhibitor is added to the first purification column and the second purification column, respectively.

12) The present invention according to any one of 1) to 11) above, wherein the monomer mixture contains 65 to 85% by weight of the regenerated (meth)acrylate-based monomer; 8 to 26% by weight of the vinyl aromatic monomer; and 1 to 17% by weight of the vinyl cyanide monomer.

13) The present invention provides a non-grafted polymer having a purity of 99.0% or more, a b value measured by the CIE LAB color coordinate system of 4.0 or less, and a β of 1.9 to 3.5 represented by the following formula 1:

<Equation 1>

In the above equation,

L’, a’, and b’ are the L, a, and b values measured using the CIE LAB color coordinate system after irradiating the ungrafted polymer with UV-A (340 nm) at 60°C for 150 hours;

L _O , a ₀ , b ₀ are the L, a, b values measured using the CIE LAB color coordinate system before light irradiation.

The method for producing a non-grafted polymer of the present invention uses regenerated (meth)acrylate-based monomers with a purity of 99.0% by weight or more by purifying waste two or more times, so that the non-grafted polymer produced from new (meth)acrylate-based monomers and Non-grafted polymers can be produced that achieve equivalent levels of purity, color, and weather resistance.

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

In the present invention, (meth)acrylate-based monomer may be an expression encompassing acrylate-based monomer and methacrylate-based monomer. The (meth)acrylate-based monomer may be an alkyl (meth)acrylate-based monomer, and specifically may be a C ₁ to C ₁₀ alkyl (meth)acrylate-based monomer. The (meth)acrylate monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, heptyl (meth)acrylate, and hexyl (meth)acrylate. , 2-ethylhexyl (meth)acrylate, and decyl (meth)acrylate. Among these, methyl methacrylate is preferable. And, the unit derived from the (meth)acrylate-based monomer may be a (meth)acrylate-based monomer unit.

In the present invention, vinyl aromatic monomers include styrene, 4-fluorostyrene, 4-chlorostyrene, 2-chlorostyrene, 4-bromostyrene, 2-bromostyrene, α-methyl styrene, p-methyl styrene and 2, It may be one or more types from the group consisting of 4-dimethyl styrene, and among these, styrene, which has excellent moldability, is preferable. And, a unit derived from a vinyl aromatic monomer is a vinyl aromatic monomer unit.

In the present invention, the vinyl cyanide monomer may refer to one or more types selected from the group consisting of acrylonitrile, 2-methylacrylonitrile, 2-ethylacrylonitrile, and 2-chloroacrylonitrile. Among these, acrylonitrile, which has excellent chemical resistance improvement effect, is preferable. And, the unit derived from vinyl cyanide-based monomer may be a vinyl cyanide-based monomer unit.

The term ‘polymerization’ used in the present invention may refer to ‘continuous polymerization’ that is easy to remove heat during polymerization and can produce a polymer with uniform physical properties.

The term ‘polymerization’ used in the present invention may be ‘bulk polymerization’ or ‘solution polymerization’.

In the present invention, purity can be measured by gas chromatography.

1. Method for producing non-grafted polymers

The method for producing a non-grafted polymer according to an embodiment of the present invention is 1) purifying waste containing (meth)acrylate monomers two or more times to produce regenerated (meth)acrylate monomers with a purity of 99.0% by weight or more. steps; and 2) preparing a non-grafted polymer by polymerizing a monomer mixture including the recycled (meth)acrylate monomer, vinyl aromatic monomer, and vinyl cyanide monomer.

Hereinafter, each step of the method for producing a non-grafted polymer according to an embodiment of the present invention will be described in detail.

1) Production of recycled (meth)acrylate monomer

First, waste containing (meth)acrylate monomers is purified two or more times to produce regenerated (meth)acrylate monomers with a purity of 99.0% by weight.

The waste may be one or more types selected from the group consisting of waste artificial marble and waste acrylic polymer. The waste artificial marble can be crushed to a size of 5 mm or less for easy handling. Additionally, the waste acrylic polymer can also be pulverized to a size of 1 cm or less for easy handling.

The step of producing the recycled (meth)acrylate-based monomer includes pyrolyzing the waste to produce a gas condensate containing the (meth)acrylate-based monomer; Distilling the gas condensate to prepare a preparation containing a (meth)acrylate-based monomer; Supplying the preparation to a first purification column and performing primary purification to prepare a primary purified product with low boiling point impurities removed compared to the (meth)acrylate monomer; And supplying the first purification to a second purification column and performing secondary purification to remove high boiling point impurities compared to the (meth)acrylate monomer to produce a regenerated (meth)acrylate monomer. there is.

The thermal decomposition may be performed at 400 to 700 °C, preferably 450 to 650 °C. If the above-mentioned conditions are satisfied, gas condensate containing gaseous (meth)acrylate-based monomers can be easily decomposed from the waste.

The distillation can be performed one or more times, preferably two or more times. The distillation may be performed at 50 to 90 °C, preferably 60 to 85 °C. If the above-mentioned conditions are satisfied, a preparation containing a (meth)acrylate-based monomer can be easily separated from the gas condensate.

The distillation may be performed in a distillation tower or column without a reflux condenser. Accordingly, distillate that has moved to the top of the distillation tower or column may not be recirculated to the bottom of the distillation tower or column.

The primary purification is preferably performed at a temperature 21 to 66°C lower than the boiling point of the (meth)acrylate monomer, preferably 26 to 51°C lower. If the above-mentioned conditions are satisfied, impurities with a low boiling point compared to the (meth)acrylate-based monomer can be easily removed from the preparation to the top of the first purification column due to heat.

The primary purification is preferably performed at 150 to 760 torr, preferably 100 to 760 torr. If the above-mentioned conditions are satisfied, impurities with a low boiling point compared to the (meth)acrylate-based monomer can be easily removed from the preparation to the top of the first purification column by the above-mentioned pressure even at a relatively low temperature.

Since the low boiling point impurities are vaporized at a lower temperature than the (meth)acrylate monomer, it is preferable to remove them to the top of the first purification column. It is preferable that the first purification product is recovered from the bottom of the first purification column and supplied to the second purification column.

The secondary purification is preferably performed at a temperature 11 to 56°C lower than the boiling point of the (meth)acrylate monomer, preferably 26 to 51°C lower. If the above-mentioned conditions are satisfied, impurities with a high boiling point compared to the (meth)acrylate-based monomer can be easily removed from the first purification product to the bottom of the second purification column.

The secondary purification is preferably performed at 15 to 760 torr, preferably 100 to 760 torr. If the above-mentioned conditions are satisfied, impurities with a high boiling point compared to the (meth)acrylate-based monomer can be easily removed from the first purification product by the above-mentioned pressure even at a relatively low temperature to the bottom of the second purification column.

Since the high boiling point impurities are vaporized at a higher temperature than the (meth)acrylate monomer, it is preferable to remove them to the bottom of the second purification column.

In order to prevent fouling due to self-polymerization of (meth)acrylate-based monomers in the first purification column and the second purification column, a polymerization inhibitor may be added to the first purification column and the second purification column, respectively. .

The content of the polymerization inhibitor introduced into the first purification column may be 40 to 1,000 ppm, preferably 100 to 500 ppm, based on the total weight of the preparation supplied to the first purification column. If the above-mentioned conditions are satisfied, it is possible to prevent the (meth)acrylate-based monomer from self-polymerizing in the first purification column and prevent the polymerization inhibitor from remaining in the regenerated (meth)acrylate-based monomer.

The content of the polymerization inhibitor introduced into the second purification column may be 1,000 to 2,000 ppm, preferably 1,200 to 1,800 ppm, based on the total weight of the first purified product supplied to the second purification column. If the above-mentioned conditions are satisfied, it is possible to prevent the (meth)acrylate-based monomer from self-polymerizing in the second purification column and prevent the polymerization inhibitor from remaining in the regenerated (meth)acrylate-based monomer.

The polymerization inhibitor may be at least one selected from the group consisting of 2,4-dimethyl-6-tert-butylphenol and hydroquinone monomethyl ether.

The first and second purification columns are purification columns equipped with reflux condensers and may have multiple stages therein. Due to the reflux condenser, distillate moving to the top of the first and second purification columns can be condensed and recirculated to the bottom.

2) Preparation of non-grafted polymer

Next, a non-grafted polymer is prepared by polymerizing the monomer mixture including the recycled (meth)acrylate monomer, vinyl aromatic monomer, and vinyl cyanide monomer.

The monomer mixture may include 65 to 85% by weight, preferably 70 to 80% by weight, of the recycled (meth)acrylate-based monomer. If the above-mentioned conditions are satisfied, a non-grafted polymer with excellent transparency can be produced.

The monomer mixture may include 8 to 26% by weight of the vinyl aromatic monomer, preferably 13 to 21% by weight. If the above-mentioned conditions are satisfied, a non-grafted polymer with excellent processability can be produced.

The monomer mixture may include 1 to 17% by weight and 2 to 12% by weight of the vinyl cyanide monomer. If the above-mentioned conditions are satisfied, it is possible to produce a non-grafted polymer with excellent chemical resistance while minimizing the appearance of yellow color.

The polymerization may be performed in the presence of at least one selected from the group consisting of an initiator and a molecular weight regulator.

The initiator is 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-2-methylcyclohexane, 1,1-bis(t-butylperoxy)- It may be one or more selected from the group consisting of 3,3,5-trimethylcyclohexane and 2,2-bis(t-butylperoxy)butane.

The content of the initiator may be 0.01 to 1.00 parts by weight, preferably 0.01 to 0.50 parts by weight, based on 100 parts by weight of the total monomer content added in the method for producing the non-grafted polymer. If the above-mentioned range is satisfied, polymerization can be performed stably.

The molecular weight regulator is 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, It may be one or more types selected from the group consisting of dipentamethylene thiuram dipulphide and diisopropyl xanthogen disulfide. Among these, t-dodecyl mercaptan is preferred.

The content of the molecular weight regulator may be 0.01 to 1.50 parts by weight, preferably 0.10 to 1.00 parts by weight, based on 100 parts by weight of the total monomer content added in the method for producing the non-grafted polymer. If the above-mentioned range is satisfied, polymerization can be performed stably.

When the polymerization is a solution polymerization, the solvent used in the polymerization may be one or more selected from the group consisting of methyl ethyl ketone, ethylbenzene, toluene, carbon tetrachloride, and chloroform.

In order to prevent polymerization from being performed smoothly due to a decrease in viscosity of the monomer mixture, the content of the solvent is 20.0 parts by weight or less based on 100 parts by weight of the total monomer content added in the method for producing the non-grafted polymer. It is desirable.

2. Non-grafted polymers

The ungrafted polymer according to another embodiment of the present invention has a purity of 99.0% or more, a b value measured by the CIE LAB color coordinate system of 4.0 or less, and ΔE expressed by the following equation 1 is 1.9 to 3.5:

<Equation 1>

In the above equation,

L’, a’, and b’ are the L, a, and b values measured using the CIE LAB color coordinate system after irradiating the ungrafted polymer with UV-A (340 nm) at 60°C for 150 hours;

L _O , a ₀ , b ₀ are the L, a, b values measured using the CIE LAB color coordinate system before light irradiation.

The non-grafted polymer preferably has a purity of 99.2% or more. If the above-mentioned conditions are met, side effects due to impurities can be prevented.

The non-grafted polymer preferably has a b value of 3.7 or less as measured by the CIE LAB color coordinate system. If the above-mentioned conditions are satisfied, the appearance of yellow color of the non-grafted polymer can be minimized.

The non-grafted polymer preferably has ΔE of 1.9 to 3.0. If the above-mentioned conditions are satisfied, weather resistance is excellent and oxidation by light can be minimized.

A non-grafted polymer according to another embodiment of the present invention can be produced by the method for producing a non-grafted polymer according to an embodiment of the present invention.

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

Manufacturing Example 1

Veolia R&E's recycled methyl methacrylate (produced by thermal decomposition of waste and then distillation) was purified for 5 hours in the first purification column (temperature: 35 to 80 ℃, pressure: 100 to 760 torr). , was prepared by secondary purification for 5 hours in a second purification column (temperature: 45 to 90 °C, pressure: 100 to 760 torr). Meanwhile, 2,4-dimethyl-6-tert-butylphenol as a polymerization inhibitor was added to the first purification column at 500 ppm based on the total weight of the regenerated methyl methacrylate supplied to the first purification column, and the second purification column 2,4-dimethyl-6-tert-butylphenol as a polymerization inhibitor was added to the column at 1,400 ppm based on the total weight of the first purified product supplied to the second purification column. In addition, the first purification column and the second purification column were each equipped with a reflux condenser.

Production example 2

Recycled methyl methacrylate (produced by pyrolyzing waste and then distilling it) from Veolia R&E was used.

Reference example 1

New methyl methacrylate was used.

The purity of methyl methacrylate in Preparation Examples 1 and 2 and Reference Example 1 was measured by the method below.

1) Purity (% by weight): Purity was measured by gas chromatography using fresh methyl methacrylate (purity: 99.96% by weight) as a standard material.

division Manufacturing Example 1 Production example 2 Reference example 1 Purity (weight) 99.3 97.1 99.9

Example 1

Preparation Example 1: 70 parts by weight of regenerated methyl methacrylate, 17 parts by weight of styrene, 6.5 parts by weight of acrylonitrile, 6.5 parts by weight of toluene, 0.12 parts by weight of 1,1-bis(t-butylperoxy)cyclohexane, and t- A polymerization solution was prepared by mixing 0.46 parts by weight of dodecyl mercaptan.

The polymerization solution was continuously added to the first reactor (internal temperature: 135°C) at a rate of 12 kg/h, and was continuously polymerized while remaining in the first reactor for 75 minutes to prepare a first polymer mixture.

Subsequently, the first polymer mixture was continuously added to the second reactor (internal temperature: 140°C) at a rate of 12 kg/h, and stayed in the second reactor for 75 minutes to continuously polymerize to prepare the second polymer mixture. did.

Subsequently, the second polymer mixture was continuously added to the third reactor (internal temperature: 145°C) at a rate of 12 kg/h, and was continuously polymerized while remaining in the second reactor for 75 hours to prepare the third polymer mixture. did.

While the third polymer mixture was continuously added to the devolatilization tank (internal temperature: 235°C, internal pressure: 15 torr), unreacted monomers and toluene were recovered and removed, and a non-grafted polymer in the form of a pellet was prepared.

Meanwhile, continuous polymerization in the first to third reactors was performed after reaching a steady state.

Comparative Example 1

In Example 1, a non-grafted polymer in the form of a pellet was prepared in the same manner as Example 1, except that the regenerated methyl methacrylate of Preparation Example 2 was used instead of the regenerated methyl methacrylate of Preparation Example 1.

Reference example 1

In Example 1, a non-grafted polymer in the form of a pellet was prepared in the same manner as in Example 1, except that the new methyl methacrylate of Reference Example 1 was used instead of the regenerated methyl methacrylate of Preparation Example 1.

Experimental Example 1

The physical properties of Example 1, Comparative Example 1, and Reference Example 1 were measured by the method described below, and the results are shown in Table 2 below.

1) Impurities (% by weight): The content of impurities was measured by gas chromatography. The type of impurity was confirmed using a gas chromatograph library.

2) Refractive index: The refractive index of the specimen (thickness: 3.175 mm) was measured at 25°C with an Abbe refractometer according to ASTM D542.

3) Haze (%): The haze of the specimen (thickness: 3.175 mm) was measured at 25°C with a haze meter (Haze Meter HZ-V3, SUGA Test Instrument) according to ASTM D1003.

4) Transparency: The transparency of the specimen (thickness: 3.175 mm) was measured at 25°C with a haze meter (Haze Meter HZ-V3 from SUGA Test Instrument) in accordance with ASTM D1003.

5) Weight average molecular weight (g/mol) and molecular weight distribution: Weight average molecular weight and number average molecular weight as relative values to a standard polystyrene sample using gel permeation chromatography (GPC, Waters Breeze) using tetrahydrofuran as the eluent. was measured. Then, the molecular weight distribution was calculated by dividing the weight average molecular weight by the number average molecular weight.

Column: Waters styragel HR2~4

Flow rate: 1.0 ml/min

6) b value: b value was measured using the CIE LAB color coordinate system.

7) △E: △E is derived from Equation 1 below, and the closer the △E value is to 0, the better the weather resistance is.

<Equation 1>

In the above equation, L’, a’, and b’ are the L, a, and b values measured using the CIE LAB color coordinate system after irradiating UV-A (340 nm) at 60°C for 150 hours on the ungrafted polymer,

L _O , a ₀ , b ₀ are the L, a, b values measured using the CIE LAB color coordinate system before light irradiation.

division Example 1 Comparative Example 1 Reference example 1 impurities
(weight%) 2-Propenoic acid, methyl ester 0.0027 0.0033 0.0023 Methyl propionate 0.0066 0.0089 0.0040 Butanoic acid, 2-methyl-, methyl ester 0.0000 0.1700 0.0000 3-Pentanone, 2,4-dimethyl-(3-Pentanone, 2,4-dimethyl-) 0.0000 0.0500 0.0000 Cyclopentanone, 2-methyl- 0.0000 1.4800 0.0000 2-Butenoic acid, 3-methyl-, methyl ester 0.0000 0.0800 0.0000 p-Xylene 0.0270 0.1670 0.0620 2-Butenoic acid, 2-methyl-, methyl ester 0.0000 0.1400 0.0000 Cyclopentanone, 2,5-dimethyl- 0.0000 0.9100 0.0000 3-Heptanol 0.0000 0.1000 0.0000 2-Cyclopenten-1-one, 2-methyl- (2-Cyclopenten-1-one, 2-methyl-) 0.0000 0.1800 0.0000 2-Cyclopenten-1-one, 3,4-methyl-(2-Cyclopenten-1-one, 3,4-methyl-) 0.0000 5.5100 0.0000 4-Pentenoic acid, 2,4-dimethyl-, methyl 0.0000 0.2300 0.0000 Hexanal, 2-ethyl- 0.0000 0.1000 0.0000 3-Hexanoic acid, 2-methyl-, methyl ester 0.0000 0.3100 0.0000 Unknown impurity 0.0000 0.2500 0.0000 Benzene, 1,2,3-trimethyl- 0.0000 0.1900 0.0000 total 0.0363 9.8792 0.0683 refractive index 1.5153 1.5157 1.5153 Haze 0.2 0.3 0.2 transparency 92.6 91.6 92.4 weight average molecular weight 93,000 97,000 92,000 Molecular weight distribution 1.9 1.9 1.9 b value 3.8 6.4 3.7 △E 1.9 5.8 1.4

Referring to Table 2, Example 1 contained a significantly small amount of impurities compared to Comparative Example 1. Example 1 had a low refractive index and haze, high transparency, and excellent weather resistance compared to Comparative Example 1.

Additionally, Example 1 contained a significantly small amount of impurities compared to Reference Example 1. Example 1 implemented a b value equivalent to that of Reference Example 1, but the ΔE value was somewhat higher.

Claims (13)

Purifying waste containing (meth)acrylate monomers two or more times to produce regenerated (meth)acrylate monomers with a purity of 99.0% by weight or more; and
Preparing a non-grafted polymer by polymerizing a monomer mixture including the regenerated (meth)acrylate monomer, vinyl aromatic monomer, and vinyl cyanide monomer.
In claim 1,
A method for producing a non-grafted polymer, wherein the waste is at least one selected from the group consisting of waste artificial marble and waste acrylic polymer.
In claim 1,
The step of producing the recycled (meth)acrylate monomer is
pyrolyzing the waste to produce a gas condensate containing (meth)acrylate-based monomers;
Distilling the gas condensate to prepare a preparation containing a (meth)acrylate-based monomer;
Supplying the preparation to a first purification column and performing primary purification to prepare a primary purified product with low boiling point impurities removed compared to the (meth)acrylate monomer; and
A step of supplying the first purification to a second purification column and performing secondary purification to remove high boiling point impurities compared to the (meth)acrylate monomer to produce a regenerated (meth)acrylate monomer. Method for producing non-grafted polymers.
In claim 3,
A method for producing a non-grafted polymer, wherein the thermal decomposition is performed at 400 to 700 °C.
In claim 3,
A method for producing a non-grafted polymer, wherein the first purification is performed at a temperature 21 to 66 ° C lower than the boiling point of the (meth)acrylate monomer.
In claim 3,
A method for producing a non-grafted polymer, wherein the first purification is performed at 100 to 760 torr.
In claim 3,
A method for producing a non-grafted polymer, wherein the low boiling point impurities are removed to the top of the first purification column.
In claim 3,
A method for producing a non-grafted polymer, wherein the secondary purification is performed at a temperature 11 to 56 ° C lower than the boiling point of the (meth)acrylate monomer.
In claim 3,
A method for producing a non-grafted polymer, wherein the secondary purification is performed at 100 to 760 torr.
In claim 3,
A method for producing a non-grafted polymer, wherein the high boiling point impurities are removed from the bottom of the second purification column.
In claim 3,
A method for producing a non-grafted polymer, wherein a polymerization inhibitor is added to the first purification column and the second purification column, respectively.
In claim 1,
The monomer mixture is
65 to 85% by weight of the recycled (meth)acrylate monomer;
8 to 26% by weight of the vinyl aromatic monomer; and
A method for producing a non-grafted polymer comprising 1 to 17% by weight of the vinyl cyanide monomer.
The purity is over 99.0%,
The b value measured using the CIE LAB color coordinate system is 4.0 or less,
A non-grafted polymer having ΔE of 1.9 to 3.5, represented by the following formula 1:
<Equation 1>

In the above equation,
L', a', and b' are the L, a, and b values measured using the CIE LAB color coordinate system after irradiating the ungrafted polymer with UV-A (340 nm) at 60°C for 150 hours,
L _O , a ₀ , b ₀ are the L, a, b values measured using the CIE LAB color coordinate system before light irradiation.