KR20230010495A - Method for preparing vinyl chloride-based polymer - Google Patents

Abstract

The present invention relates to a manufacturing method of a vinyl chloride-based polymer, which comprises the steps of: manufacturing a mixture containing a vinyl chloride monomer and a maleimide-based polymer; and polymerizing the mixture to manufacture a vinyl chloride polymer. The present invention is to provide the manufacturing method of the vinyl chloride-based polymer having excellent heat resistance while maintaining basic physical properties.

Description

Manufacturing method of vinyl chloride-based polymer {METHOD FOR PREPARING VINYL CHLORIDE-BASED POLYMER}

The present invention relates to a method for producing a vinyl chloride-based polymer, and more specifically, to a method for producing a vinyl chloride-based polymer having excellent heat resistance.

Since vinyl chloride-based polymers have flexible and hard properties, they are mainly used for various purposes, especially windows and doors.

In the past, white-colored windows were preferred, but recently, the trend has changed to prefer windows of various colors. In addition, since windows of various colors, especially black windows, have higher heat absorption rates than white windows, a problem of bending of windows occurs in summer when the temperature is high. In order to improve this problem, a method of compounding a polymer having excellent heat resistance with a vinyl chloride-based polymer has been proposed, but a problem of increasing manufacturing cost due to the additional installation of an extrusion device for compounding and the resulting additional process has occurred.

Accordingly, studies to improve the heat resistance of the vinyl chloride-based polymer itself are being continued while minimizing the increase in manufacturing cost.

KR2017-0004703A

The problem to be solved by the present invention is to provide a method for producing a vinyl chloride-based polymer having excellent heat resistance while maintaining basic physical properties.

In order to solve the above problems, the present invention comprises the steps of preparing a mixture containing a vinyl chloride-based monomer and a maleimide-based polymer; and polymerizing the mixture to prepare a vinyl chloride polymer.

The vinyl chloride-based polymer prepared by the production method of the present invention has remarkably excellent heat resistance while maintaining basic physical properties. Therefore, it is suitable for use as a raw material for windows and doors having various colors.

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

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

In the present invention, the 'vinyl chloride-based polymer' is a homopolymer prepared by polymerizing a vinyl chloride-based monomer alone; Alternatively, it may be a copolymer prepared by copolymerizing a vinyl chloride monomer and a comonomer copolymerizable with the vinyl chloride monomer. The vinyl chloride-based monomer may be vinyl chloride. The comonomer is ethylene, propylene, vinyl acetate, vinyl propionate, acrylonitrile, methyl vinyl ether, ethyl vinyl ether, acrylic acid, acrylic anhydride, methacrylic acid, methacrylic anhydride, itaconic acid, itaconic anhydride, maleic acid And it may be at least one selected from the group consisting of maleic anhydride.

In the present invention, the 'vinyl aromatic monomer' may be at least one selected from the group consisting of styrene, α-methyl styrene, α-ethyl styrene, and p-methyl styrene, of which styrene is preferred.

In the present invention, the 'vinyl cyanide-based monomer' may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, phenylacrylonitrile, and α-chloroacrylonitrile, of which acrylonitrile is preferred. Do.

In the present invention, the 'maleimide-based monomer' includes maleimide, N-methyl maleimide, N-ethyl maleimide, N-propyl maleimide, N-isopropyl maleimide, N-butyl maleimide, and N-isobutyl maleimide. , N-t-butyl maleimide, N-lauryl maleimide, N-cyclohexyl maleimide, N-phenyl maleimide, N-(4-chlorophenyl) maleimide, 2-methyl-N-phenyl maleimide, N- (4-bromophenyl) maleimide, N-(4-nitrophenyl) maleimide, N-(4-hydroxyphenyl) maleimide, N-(4-methoxyphenyl) maleimide, N-(4- It may be at least one selected from the group consisting of carboxyphenyl) maleimide and N-benzyl maleimide, among which N-phenyl maleimide is preferred.

In the present invention, the 'maleic acid monomer' may be at least one selected from the group consisting of maleic anhydride, maleic acid, maleic monoester, and maleic diester. Heavy maleic anhydride is preferred.

Manufacturing method of vinyl chloride-based polymer

A method for producing a vinyl chloride-based polymer according to an embodiment of the present invention includes preparing a mixture including a vinyl chloride-based monomer and a maleimide-based polymer; and polymerizing the mixture to prepare a vinyl chloride-based polymer.

As a method of improving the heat resistance of the vinyl chloride polymer, there may be a method of compounding with a heat resistant polymer. This method requires an additional process for compounding, and a heat resistant polymer having excellent compatibility with the vinyl chloride polymer may be prepared. There is a problem that is difficult to find.

On the other hand, maleimide-based polymers have excellent heat resistance and are usable, but when mixed with vinyl chloride-based polymers, uniform dispersion itself may not occur, or even if dispersed, phase separation may occur again within a short time. It is difficult to expect an effect of improving the heat resistance of the vinyl chloride polymer.

However, as in the present invention, when a mixture containing a vinyl chloride monomer and a maleimide polymer is prepared before polymerization starts, the maleimide polymer is uniformly dispersed in the final product, the vinyl chloride polymer, so that the vinyl chloride polymer Heat resistance is remarkably improved. In addition, it is possible to minimize a phenomenon in which the maleimide-based polymer is separated from the final product, the vinyl chloride-based polymer.

In addition, the maleimide-based polymer included in the mixture is powdery in nature, and may be very advantageous in dispersion in the mixture containing the vinyl chloride-based monomer. On the other hand, it is impossible to realize the effect of improving heat resistance by including the monomers constituting the maleimide-based polymer in the mixture, but the maleimide-based monomer, which is one of the monomers constituting the maleimide-based polymer, is superior to the maleimide-based polymer. This is because dispersion in the mixture may be very difficult due to a remarkably large particle diameter, and alkyl-substituted styrene-based monomers such as α-methyl styrene have poor reactivity with vinyl chloride-based monomers and may be treated as simple impurities after polymerization. Therefore, it is difficult to prepare a vinyl chloride-based polymer having improved heat resistance by including monomers constituting the same other than the maleimide-based polymer.

The mixture may include 100 parts by weight of the vinyl chloride monomer and 3.0 to 6.0 parts by weight of the maleimide-based polymer, and preferably include 100 parts by weight of the vinyl chloride monomer and 4.0 to 5.0 parts by weight of the maleimide-based polymer. there is. If the above conditions are satisfied, heat resistance can be remarkably improved while maintaining thermal stability and color characteristics, which are basic physical properties, at the same level as those of the prior art.

It is preferable to prepare by stirring so that the mixture uniformly contains the vinyl chloride-based monomer and the maleimide-based polymer. And, in order to further increase the uniformity of the mixture, it is preferable that the mixture further includes water.

Meanwhile, the maleimide-based polymer may have a glass transition temperature of 180.0 to 210.0 °C, preferably 190.0 to 200.0 °C. If the above conditions are satisfied, the dispersion of the vinyl chloride-based polymer can be uniform in the monomer mixture during polymerization, and the phase separation phenomenon in the final polymer can be prevented, thereby improving the heat resistance of the final product, the vinyl chloride-based polymer. It can be.

The maleimide-based polymer may have a weight average molecular weight of 110,000 to 140,000 g/mol, preferably 120,000 to 130,000 g/mol. If the above conditions are satisfied, there is an advantage in that mechanical properties are improved.

Here, the weight average molecular weight can be measured as a relative value with respect to standard polystyrene through gel permeation chromatography.

The maleimide-based polymer may be a polymer including a maleimide-based monomer unit, a vinyl aromatic monomer unit, and a maleic acid monomer unit, among which N- Phenylmaleimide/styrene/maleic anhydride polymers are preferred.

On the other hand, the polymerization is preferably suspension polymerization capable of producing a variety of products in small quantities, and when a dispersant and an initiator for suspension polymerization are added in the mixing step, polymerization is initiated and the vinyl chloride-based monomer and the maleimide-based polymer are mixed in advance. can't Since a vinyl chloride polymer having improved heat resistance cannot be prepared unless the vinyl chloride monomer and the maleimide polymer are mixed in advance, the method for preparing a vinyl chloride polymer according to an embodiment of the present invention is performed after the mixing step It is preferable to perform the step of adding a dispersant and an initiator to the mixture.

The dispersant is polyvinyl alcohol, polyacrylic acid, a copolymer of vinyl acetate and maleic anhydride, hydroxypropyl methylcellulose, gelatin, calcium phosphate, hydroxyapatite, sorbitan monolaurate, sorbitan trioleate, polyoxyethylene, It may be at least one selected from the group consisting of sodium lauryl sulfate, sodium dodecylbenzenesulfonate and sodium dioctylsulfosuccinate.

The content of the dispersant may be 0.0100 to 0.3000 parts by weight, preferably 0.0500 to 0.2500 parts by weight, based on 100 parts by weight of the vinyl chloride monomer. If the above conditions are satisfied, a vinyl chloride-based polymer having a desired grade can be produced.

The initiator is dicumyl peroxide, dipentyl peroxide, di(3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, diisopropyl peroxidacarbonate, di-sec-butylperoxide Carbonate, di(2-ethylhexyl)peroxy dicarbonate, t-butylperoxy neodecanoate, t-butylperoxy neoheptanoate, t-amyl peroxy neodecanoate, cumyl peroxyneodecano ate, cumyl peroxyneoheptanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, azobis-2,4-dimethylvaleronitrile, potassium persulfate and ammonium persulfate It may be one or more selected from.

The amount of the initiator may be 0.0100 to 0.2000 parts by weight, preferably 0.0500 to 0.1500 parts by weight, based on 100 parts by weight of the vinyl chloride monomer. When the above conditions are satisfied, polymerization can be stably performed while minimizing the influence on the odor and color characteristics of the final product.

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

Example 1

After adding 135 parts by weight of ion-exchanged water and 100 parts by weight of vinyl chloride monomer to a stainless steel polymerization reactor (internal volume: 1 m 3) equipped with a reflux condenser and a stirrer, N-phenylmaleimide / styrene / maleic anhydride polymer (Denka Co. MSNB) 3.0 parts by weight was added and mixed in advance by stirring at a speed of 200 rpm for 90 minutes. Thereafter, 0.2000 parts by weight of hydroxypropyl methylcellulose (FMC60150 from Lotte Fine Chemical), 0.096 parts by weight of t-butylperoxy neodecanoate, and 0.024 parts by weight of cumyl peroxyneodecanoate were added to the polymerization reactor, and 200 rpm While stirring at high speed, the inside was degassed with a vacuum pump. The polymerization was performed while maintaining the internal temperature of the polymerization reactor at 57.2° C., and the polymerization was stopped when the pressure of the polymerization reactor changed by 1.0 kg/cm 2 compared to before polymerization. After stopping the polymerization, triethylene glycol bis(3-t-butyl-4-hydroxy-5-methylphenyl)propionate was introduced. Thereafter, unreacted monomers were recovered and a vinyl chloride polymer slurry was recovered from the reactor.

Stripping and dehydration were performed on the vinyl chloride polymer slurry, followed by hot air drying to obtain a vinyl chloride polymer powder.

Example 2

After adding 135 parts by weight of ion-exchanged water and 100 parts by weight of vinyl chloride monomer to a stainless steel polymerization reactor (internal volume: 1 m 3) equipped with a reflux condenser and a stirrer, N-phenylmaleimide / styrene / maleic anhydride polymer (Denka Co. MSNB) 3.0 parts by weight was added and mixed in advance by stirring at a speed of 200 rpm for 90 minutes. Thereafter, 0.0484 parts by weight of polyvinyl alcohol 1 (JP27Y from JAPAN VAN & POVAL CO. LTD, degree of hydration: 88 mol%) and 0.0326 part by weight of polyvinyl alcohol 2 (ALCOTEX B72 from SYNTHOMER, degree of hydration: 72 mol%) were added to the polymerization reactor. part, polyvinyl alcohol 3 (ALCOTEX 55 from SYNTHOMER, degree of hydration: 55 mol%) 0.0178 parts by weight, hydroxypropyl methylcellulose (FMC60150 from Lotte Fine Chemical) 0.0109 parts by weight, t-butylperoxy neodecanoate 0.096 parts by weight 0.024 parts by weight of part and cumyl peroxyneodecanoate were added, and the inside was degassed with a vacuum pump while stirring at a speed of 200 rpm. The polymerization was performed while maintaining the internal temperature of the polymerization reactor at 57.2° C., and the polymerization was stopped when the pressure of the polymerization reactor changed by 1.0 kg/cm 2 compared to before polymerization. After stopping the polymerization, triethylene glycol bis(3-t-butyl-4-hydroxy-5-methylphenyl)propionate was introduced. Thereafter, unreacted monomers were recovered and a vinyl chloride polymer slurry was recovered from the reactor.

Stripping and dehydration were performed on the vinyl chloride polymer slurry, followed by hot air drying to obtain a vinyl chloride polymer powder.

Example 3

A vinyl chloride polymer powder was prepared in the same manner as in Example 1, except that 6.0 parts by weight of the N-phenylmaleimide/styrene/maleic anhydride polymer was added in Example 2.

Comparative Example 1

135 parts by weight of ion-exchanged water, 0.2000 parts by weight of hydroxypropyl methylcellulose, 0.096 parts by weight of t-butylperoxy neodecanoate, cumyl peroxy 0.024 part by weight of neodecanoate was added, and the inside was degassed with a vacuum pump while stirring at a speed of 200 rpm. The polymerization was performed while maintaining the internal temperature of the polymerization reactor at 57.2° C., and the polymerization was stopped when the pressure of the polymerization reactor changed by 1.0 kg/cm 2 compared to before polymerization. After stopping the polymerization, triethylene glycol bis(3-t-butyl-4-hydroxy-5-methylphenyl)propionate was introduced. Thereafter, unreacted monomers were recovered and a vinyl chloride polymer slurry was recovered from the reactor.

Stripping and dehydration were performed on the vinyl chloride polymer slurry, followed by hot air drying to obtain a vinyl chloride polymer powder.

Comparative Example 2

135 parts by weight of ion-exchanged water and 1 part by weight of polyvinyl alcohol (JP27Y from JAPAN VAN & POVAL CO. LTD, degree of hydration: 88 mol%) 0.0484 parts by weight , Polyvinyl alcohol 2 (SYNTHOMER's ALCOTEX B72, hydration degree: 72 mol%) 0.0326 parts by weight, polyvinyl alcohol 3 (SYNTHOMER's ALCOTEX 55, hydration degree: 55 mol%) 0.0178 parts by weight, hydroxypropyl methylcellulose (Lotte Fine Chemicals FMC60150) 0.0109 parts by weight, 0.096 parts by weight of t-butylperoxyneodecanoate, and 0.024 parts by weight of cumyl peroxyneodecanoate were added, and the inside was degassed with a vacuum pump while stirring at a speed of 200 rpm. The polymerization was performed while maintaining the internal temperature of the polymerization reactor at 57.2° C., and the polymerization was stopped when the pressure of the polymerization reactor changed by 1.0 kg/cm 2 compared to before polymerization. After stopping the polymerization, triethylene glycol bis(3-t-butyl-4-hydroxy-5-methylphenyl)propionate was introduced. Thereafter, unreacted monomers were recovered and a vinyl chloride polymer slurry was recovered from the reactor.

Stripping and dehydration were performed on the vinyl chloride polymer slurry, followed by hot air drying to obtain a vinyl chloride polymer powder.

Comparative Example 3

135 parts by weight of ion-exchanged water and 1 part by weight of polyvinyl alcohol (JP27Y from JAPAN VAN & POVAL CO. LTD, degree of hydration: 88 mol%) 0.0484 parts by weight , Polyvinyl alcohol 2 (SYNTHOMER's ALCOTEX B72, hydration degree: 72 mol%) 0.0326 parts by weight, polyvinyl alcohol 3 (SYNTHOMER's ALCOTEX 55, hydration degree: 55 mol%) 0.0178 parts by weight, hydroxypropyl methylcellulose (Lotte Fine Chemical FMC60150) 0.0109 parts by weight, N-phenylmaleimide/styrene/maleic anhydride polymer (MSNB from Denka) 3.0 parts by weight, t-butylperoxy neodecanoate 0.096 parts by weight, cumyl peroxyneodecanoate 0.024 part by weight was introduced, and the inside was degassed with a vacuum pump while stirring at a speed of 200 rpm. The polymerization was performed while maintaining the internal temperature of the polymerization reactor at 57.2° C., and the polymerization was stopped when the pressure of the polymerization reactor changed by 1.0 kg/cm 2 compared to before polymerization. After stopping the polymerization, triethylene glycol bis(3-t-butyl-4-hydroxy-5-methylphenyl)propionate was introduced. Thereafter, unreacted monomers were recovered and a vinyl chloride polymer slurry was recovered from the reactor.

Stripping and dehydration were performed on the vinyl chloride polymer slurry, followed by hot air drying to obtain a vinyl chloride polymer powder.

Comparative Example 4

It was prepared in the same manner as in Comparative Example 3, except that 6.0 parts by weight of N-phenylmaleimide/styrene/maleic anhydride polymer (MSNB from Denka) was added in Comparative Example 3.

Experimental Example 1

The physical properties of the vinyl chloride polymer powders or thermoplastic resin compositions of Examples and Comparative Examples were evaluated by the methods described below, and the results are shown in Tables 1 and 2 below.

1) Glass transition temperature (Tg, ℃): measured by DSC 25 of TA Instruments using differential scanning calorimetry. Here, the glass transition temperature refers to a temperature at which the Brownian motion of the polymer chain becomes significantly more active than before, and the higher the glass transition temperature of the vinyl chloride-based polymer, the better the heat resistance.

2) Average particle diameter (μm): The average particle diameter was calculated with a particle size analyzer from Sympatec in accordance with ASTM D1921.

3) Plasticizer Absorption (%): The plasticizer absorption was calculated according to ASTM D3367. The plasticizer absorption rate is an index indicating the level at which the plasticizer can be absorbed by the external and internal morphologies of the vinyl chloride polymer. When the vinyl chloride polymer is used for hard windows, the plasticizer absorption rate is preferably 15 to 22.

division Example 1 Example 2 Example 3 polymerization whether to blend lines ○ ○ ○ Vinyl chloride monomer (parts by weight) 100.0 100.0 100.0 PNM/ST/MAH polymer (parts by weight) 3.0 3.0 6.0 PVA 1 (parts by weight) 0.0000 0.0484 0.0484 PVA 2 (parts by weight) 0.0000 0.0326 0.0326 PVA 3 (parts by weight) 0.0000 0.0178 0.0178 HPMC (parts by weight) 0.2000 0.0000 0.0000 Properties glass transition temperature 91.1 91.4 95.7 average particle diameter 139 125 142 plasticizer absorption 20.5 19.5 18.1 PNM/ST/MAH polymer: N-phenylmaleimide/styrene/maleic anhydride polymer (MSNB from Denka Co.) PVA 1: polyvinyl alcohol 1 (JP27Y from JAPAN VAN & POVAL CO. LTD, degree of hydration: 88 mol%)
PVA 2: polyvinyl alcohol 2 (ALCOTEX B72 from SYNTHOMER, degree of hydration: 72 mol%)
PVA 3: polyvinyl alcohol 3 (ALCOTEX 55 from SYNTHOMER, degree of hydration: 55 mol%)
HPMC: Hydroxypropyl methylcellulose (FMC60150 from Lotte Fine Chemical)

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 polymerization whether to blend lines × × × × Vinyl chloride monomer (parts by weight) 100.0 100.0 100.0 100.0 PNM/ST/MAH polymer (parts by weight) 0.0 0.0 3.0 6.0 PVA 1 (parts by weight) 0 0.0484 0.0484 0.0484 PVA 2 (parts by weight) 0 0.0326 0.0326 0.0326 PVA 3 (parts by weight) 0 0.0178 0.0178 0.0178 HPMC (parts by weight) 0.2000 0.0000 0.0000 0.0000 composition Vinyl Chloride Polymer Powder
(parts by weight) 0 0 0 0 PNM/ST/MAH polymer (parts by weight) 0 0 0 0 Properties glass transition temperature 85.2 85.4 85.7 89.7 average particle diameter 142 146 152 139 plasticizer absorption 20.2 18.5 18.3 17.9 PNM/ST/MAH polymer: N-phenylmaleimide/styrene/maleic anhydride polymer (MSNB from Denka)
PVA 1: polyvinyl alcohol 1 (JP27Y from JAPAN VAN & POVAL CO. LTD, degree of hydration: 88 mol%)
PVA 2: polyvinyl alcohol 2 (ALCOTEX B72 from SYNTHOMER, degree of hydration: 72 mol%)
PVA 3: polyvinyl alcohol 3 (ALCOTEX 55 from SYNTHOMER, degree of hydration: 55 mol%)
HPMC: Hydroxypropyl methylcellulose (FMC60150 from Lotte Fine Chemical)

Referring to Tables 1 and 2, after mixing 100.0 parts by weight of vinyl chloride monomer and 3.0 parts by weight of N-phenylmaleimide/styrene/maleic anhydride polymer in advance, polymerization was performed using only hydroxypropyl methylcellulose as a dispersing agent. Example 1 was remarkably superior in glass transition temperature compared to Comparative Example 1 in which N-phenylmaleimide/styrene/maleic anhydride was not used.

In addition, comparing Example 2 and Comparative Example 2 with the same type and amount of dispersant, 100.0 parts by weight of vinyl chloride monomer and 3.0 parts by weight of N-phenylmaleimide/styrene/maleic anhydride polymer were mixed in advance, followed by poly Example 2, which was polymerized using three types of vinyl alcohol and hydroxypropyl methylcellulose, had a significantly superior glass transition temperature compared to Comparative Example 2, which did not use N-phenylmaleimide/styrene/maleic anhydride polymer.

In addition, Example 2 had a significantly superior glass transition temperature and a high plasticizer absorption compared to Comparative Example 3, in which 3.0 parts by weight of the N-phenylmaleimide/styrene/maleic anhydride polymer was polymerized without pre-mixing.

In addition, after mixing 100.0 parts by weight of vinyl chloride monomer and 6.0 parts by weight of N-phenylmaleimide/styrene/maleic anhydride polymer in advance, Example 3 was polymerized using three types of polyvinyl alcohol and hydroxypropyl methylcellulose as dispersants. , the glass transition temperature was significantly higher than that of Comparative Example 2.

In addition, Example 3 was remarkably superior in glass transition temperature compared to Comparative Example 4 in which 6.0 parts by weight of N-phenylmaleimide/styrene/maleic anhydride polymer was polymerized without mixing in advance.

Claims (8)

preparing a mixture containing a vinyl chloride-based monomer and a maleimide-based polymer; and
Method for producing a vinyl chloride-based polymer comprising the step of polymerizing the mixture to prepare a vinyl chloride-based polymer.
The method of claim 1,
Wherein the mixture comprises 100 parts by weight of the vinyl chloride monomer and 3.0 to 6.0 parts by weight of the maleimide polymer.
The method of claim 1,
The method for producing a vinyl chloride-based polymer, wherein the mixture is prepared by stirring a vinyl chloride-based monomer and a maleimide-based polymer.
The method of claim 1,
The mixture is a method for producing a vinyl chloride-based polymer containing water.
The method of claim 1,
The maleimide-based polymer has a glass transition temperature of 180.0 to 210.0 ℃ method for producing a vinyl chloride-based polymer.
The method of claim 1,
The maleimide-based polymer is a method for producing a vinyl chloride-based polymer comprising a maleimide-based monomer unit, a vinyl aromatic-based monomer unit and a maleic acid monomer unit.
The method of claim 1,
The polymerization is a method for producing a vinyl chloride-based polymer that is suspension polymerization.
The method of claim 1,
Method for producing a vinyl chloride-based polymer comprising the step of adding a dispersant and an initiator to the mixture after the mixing step.