WO2019212217A1 - Vinyl chloride polymer and method for preparing same - Google Patents

Abstract

The present invention relates to a vinyl chloride polymer and a method for preparing same and, more specifically, to a vinyl chloride polymer of which the polydispersity index is 2.0 to 2.3 and the porosity is 60% or higher, and a method for preparing the vinyl chloride polymer. More particularly, in the method for preparing the vinyl chloride polymer, a vinyl chloride polymerization seed having a conversion rate of 5 to 20% is first prepared by means of prepolymerization, and then a vinyl chloride monomer is input to the vinyl chloride polymerization seed and a vinyl chloride polymer is polymerized (main polymerization), wherein the temperature differential between the prepolymerization and the main polymerization is adjusted to 5 to 15 °C. The preparation method has the advantage of increasing polymerization productivity. The vinyl chloride polymer polymerized by means of the preparation method shows said physical properties and thus has the advantages of enhancing the fish eye quality and initial coloration as well as enabling excellent processability.

Description

Vinyl chloride polymer and preparation method thereof

Cross Citation with Related Applications

This application claims the benefit of priority based on Korean Patent Application No. 10-2018-0049563 of April 30, 2018 and Korean Patent Application No. 10-2019-0048264 of April 25, 2019, All contents disclosed are included as part of this specification.

Technical Field

The present invention relates to a vinyl chloride polymer having excellent processability, improved fish eye and initial coloring properties, and a method for producing a vinyl chloride polymer having improved polymerization productivity.

Vinyl chloride polymers are inexpensive and have a good quality balance and are used in various fields such as hard and soft. Specifically, in the hard field, it is used for pipes, films, window frames, and the like, and in the soft field, it is used for wire coating, wrap films, sheets, and the like.

In general, it is important to improve the polymerization productivity per unit volume of the reaction as a method for reducing the manufacturing cost of the vinyl chloride polymer and improving the process efficiency. As a method for improving the polymerization productivity, for example, the polymerization reaction time is constant and the polymerization conversion rate is increased to increase the yield per batch and to shorten the polymerization reaction time.

As a method of increasing the polymerization conversion rate in such a polymerization productivity improving method, a method of further adding a polymerization initiator of a vinyl chloride polymer has been proposed. For example, U.S. Patent Publication No. 2005-008027 discloses a method of increasing the polymerization conversion rate by additionally adding an initiator at the time when the internal pressure of the polymerization reactor is lowered. However, the vinyl chloride polymer obtained by the above method slightly increased the polymerization conversion rate. However, since the polymerization conversion rate is 70% or more at the time when the pressure inside the polymerization reactor decreases, the effect of increasing the polymerization conversion rate by the initiator added at this point is insignificant. In addition, there is a problem that the initial colorability is lowered due to an increase in the amount of whiskey or an increase in fine particles. In addition, when considering the quality of the vinyl chloride polymer, considering that the general polymerization conversion rate is 83 to 85%, the method of increasing the polymerization conversion rate does not have a great effect in improving the polymerization productivity. Therefore, most efforts have been made to shorten the polymerization reaction time in order to improve the productivity of the vinyl chloride resin.

As a method of shortening the polymerization reaction time of a vinyl chloride polymer, US Patent Publication No. 2005-0054795 describes a method of introducing an initiator having a short half-life in the middle of a reaction. However, since the initiator having a short half-life is introduced in the middle of the reaction by the above method, a non-uniform internal particle form is formed by locally generated heat of reaction, thereby increasing the fish-eye.

In addition, Japanese Patent Application Laid-Open No. 1998-338701 discloses a method of shortening the polymerization reaction time by using an oil-soluble initiator and a water-soluble initiator in the initial stage of polymerization, and US Pat. No. 6,861,488 discloses an oil-soluble polymerization initiator, t-amylperoxyneodecanoate, and a peroxide type A method for producing a vinyl chloride polymer that prevents initial discoloration under suspension polymerization using a polymerization initiator has been described. However, although the reaction time shortening effect by the above methods can be expected to some extent, in the production of vinyl chloride polymer, vinyl chloride monomer is a substance having useful properties, and in the initial stage of polymerization, vinyl chloride monomer and deionized water, which is polymerized water, Since most of the unreacted vinyl chloride monomer which is present in the phase separated state and then the polymerization reaction proceeds and the polymerization conversion rate of 60% or more is not converted into the polymer is dissolved in the aqueous phase, the water-soluble initiator used together with the oil-soluble initiator at the beginning of the reaction. In addition, the effect of shortening the reaction time is not large, and there remains a problem in which the whiskey is generated by the fine particles generated by the initial water-soluble initiator in the polymerization reaction.

As described above, the above methods may cause problems inferior in quality, such as the proposed methods in terms of improving the polymerization productivity, such as the fiscia or initial colorability of the polymer to be produced, and furthermore cannot guarantee the processability of the produced polymer. there is a problem.

Accordingly, there is a need for a method for preparing a vinyl chloride polymer and a vinyl chloride polymer that can improve the quality of the polymer such as whiskey and initial coloring property while improving the polymerization productivity.

(Prior art document)

(Patent Document 1) US 2005-008027A

(Patent Document 2) US 2005-0054795A

(Patent Document 3) JP 1998-338701A

An object of the present invention was devised to solve the problems of the prior art, while solving the problem of low polymerization productivity during the production of vinyl chloride polymer, solving the problem of lowering the whiskey and initial colorability due to undissolved particles of the reactants To provide a method for producing a vinyl chloride polymer having excellent processability, specifically to prepare a vinyl chloride polymerization seed having a conversion rate of 5 to 20% in a prepolymerization reactor, the vinyl chloride polymerization seed to the present polymerization reactor It is to provide a production method for polymerizing vinyl chloride polymer by controlling the difference in the polymerization temperature of the pre-polymerization and the main polymerization after the transfer.

Another object of the present invention is a vinyl chloride polymer having a polydispersity of 2.0 to 2.3, a porosity of 60% or more, and an average pore diameter of 300 nm or more. To provide a vinyl polymer.

In order to solve the above problems, the present invention provides a vinyl chloride polymer having a polydispersity (PDI) of 2.0 to 2.3, a porosity of 60% or more, and an average pore diameter of 300 nm or more.

In addition, the present invention comprises the steps of polymerizing the first vinyl chloride monomer in a prepolymerization reactor so that the polymerization conversion rate is 5 to 20% to prepare a vinyl chloride polymerization seed (step 1); And transferring the vinyl chloride polymerization seed to the present polymerization reactor and polymerizing with the second vinyl chloride monomer introduced into the present polymerization reactor to prepare a vinyl chloride polymer (step 2). The difference in the polymerization temperature of 2 is 5 to 15 ℃, the vinyl chloride polymer provides a vinyl chloride polymer manufacturing method is a vinyl chloride homopolymer.

The vinyl chloride polymer according to an embodiment of the present invention satisfies the polydispersity of 2.0 to 2.3 and satisfies the porosity of 60% or more, thereby lowering the melt viscosity when blended with a plasticizer and the like, and having excellent workability and excellent plasticizer absorption rate. There is an effect that the quality and initial coloring quality are improved.

In addition, the method for producing a vinyl chloride polymer according to an embodiment of the present invention is to polymerize such that the polymerization conversion rate is 5 to 20% through prepolymerization before the present polymerization to prepare a vinyl chloride polymerization seed, using the polymerization seed The polymerization is carried out, and at this time, by controlling the conversion rate of the polymerization seed and the difference in the polymerization temperature between the preliminary polymerization and the main polymerization, the polymerization reaction time is shortened to significantly improve the polymerization productivity, and at the same time, the workability of the polymer to be prepared The coloring property is excellent in effect.

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.

According to an embodiment of the present invention, a polydispersity index (PDI) of 2.0 to 2.3 and a porosity of the polymer (porosity) to provide a vinyl chloride polymer.

In addition, the average pore diameter (4 V / A) of the vinyl chloride polymer according to an embodiment of the present invention may be 300 nm or more.

In the present invention, "vinyl chloride polymer" refers to a compound produced by polymerizing a vinyl chloride monomer, and may mean a polymer chain derived from a vinyl chloride monomer.

In addition, in the present invention, the "polydispersity index (PDI)" is an index indicating the width of the molecular weight distribution, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw / Mn) The value representing. That is, the polydispersity is obtained by dividing the weight average molecular weight by the number average molecular weight after measuring the weight average molecular weight and the number average molecular weight. In the present invention, the number average molecular weight and the weight average molecular weight are 0.02 g of a vinyl chloride polymer sample in 20 ml of tetrahydrofuran (THF), dissolved for 24 hours, and filtered with a 0.45 um filter, followed by a GPC device (Waters 2414 Refractive Index Detector, Waters 1525). Standard sample (Styrene standard molecular weight (g / mol) 1320, 2750, 6760, 19700, 50600, 124000, measured using Binary HPLC Pump and Waters 717 Autosampler, Waters Co., Ltd.) at 25 ° C and atmospheric pressure (1atm). 279000, 768000, 1540000, 2350000) are used to draw the calibration curve and convert it.

In addition, the average pore diameter (4V / A) and porosity (porosity) of the present invention is a mercury porosity analyzer at room temperature (23 ± 2 ℃), atmospheric pressure (1 atm), specifically Auto Pore IV 9520 ( Using micromeritics, surface pore, accessible intravoid (Pacc) and inaccessible intravoid (Pinacc) were respectively measured from the amount of mercury invaded into the vinyl chloride polymer particles and derived from the measurement results. Value. At this time, the porosity (%) represents the percentage by volume.

Polyvinyl chloride polymer having a polydispersity of 2.0 to 2.3 and a porosity of 60% or more and an average pore diameter of 300 nm or more, as in the present invention, is excellent in processability, and problems of deterioration in quality and initial colorability of the fish oil may be improved. .

Specifically, the vinyl chloride polymer having a polydispersity of 2.0 to 2.3 has excellent workability and good mechanical strength. On the other hand, if the polydispersity is less than 2.0, there is a problem that the machinability deteriorates during processing because the molecular weight distribution is narrow, and if the polydispersity exceeds 2.3, the molecular weight distribution is too wide, such as plasticizers and processed raw materials, etc. When blending, mechanical properties may be reduced.

In addition, when the porosity is less than 60%, the porosity may be too low, so that the absorption rate of the plasticizer and the subsidiary materials added during processing may be lowered. As a result, uniform dispersion of the formulation may not be achieved during processing. This worsening problem may occur. In addition, when the average pore diameter is also less than 300 nm, the same problem may occur because the absorption rate of the plasticizer and the processing sub-material may be reduced when the diameter is too small.

Here, fish-eye refers to white transparent particles generated as undissolved particles of a reactant, and is an index for confirming protrusion quality of a polymer. More whiskey means less polymer quality.

Specifically, according to an embodiment of the present invention, the vinyl chloride polymer may satisfy the polydispersity, and the porosity may be 60 to 75%, and more preferably, the porosity may be 60 to 70%. In addition, the average pore diameter may be 300 to 600 nm, more preferably the average pore diameter may be 300 to 500 nm. When the numerical range is satisfied, the above-described compounding properties may be further maximized.

In addition, the vinyl chloride polymer according to an embodiment of the present invention may have a degree of polymerization of 700 to 1300, preferably 1000 to 1200. In the present invention, "degree of polymerization" indicates the number of repeated units (units or monomers) constituting the polymer and may be a value measured according to ASTM D1243-79.

In addition, the vinyl chloride polymer according to an embodiment of the present invention may be a homopolymer. The homopolymer is a polymer formed of one type of monomer, and the vinyl chloride polymer of the present invention may be a polymer polymerized using only vinyl chloride monomer.

Vinyl chloride polymer according to an embodiment of the present invention expressing the physical properties as described above may be prepared by applying a seed polymerization method. At this time, the vinyl chloride polymerization seed may be prepared by polymerization so as to have a polymerization conversion ratio of 5 to 20% in a prepolymerization reactor, and the polymerization of the main polymerization which polymerizes the final vinyl chloride polymer using the prepolymerization and the seed polymerization. The difference in temperature may be 5 to 15 ° C. Accordingly, according to another embodiment of the present invention, a method for preparing the vinyl chloride polymer is provided.

That is, the method for producing a vinyl chloride polymer according to an embodiment of the present invention comprises the steps of preparing a vinyl chloride polymerization seed in a prepolymerization reactor so that the polymerization conversion rate is 5 to 20% (step 1); And transferring the vinyl chloride polymerization seed to the present polymerization reactor and polymerizing with the second vinyl chloride monomer introduced into the present polymerization reactor to prepare a vinyl chloride polymer (step 2). The difference in the polymerization temperature of the step 1 and step 2 is 5 to 15 ℃, the vinyl chloride polymer may be a vinyl chloride homopolymer.

In addition, the method of manufacturing the vinyl chloride polymer according to an embodiment of the present invention may be a method of preparing the vinyl chloride polymer, specifically, a polyvinyl chloride polymer having a polydispersity of 2.0 to 2.3 and a porosity of 60% or more. have. Alternatively, the polydispersity may be a method of preparing a vinyl chloride polymer having a polydispersity of 2.0 to 2.3, a porosity of 60% or more, and an average pore diameter of 300 nm or more.

In addition, the polymerization of the steps 1 and 2 may be carried out by a suspension polymerization, the suspension polymerization may mean that is carried out in the presence of a protective colloid preparation and a polymerization initiator. That is, the manufacturing method of the vinyl chloride polymer according to an embodiment of the present invention may be to prepare the polymer by suspension seed polymerization.

As described above, in the vinyl chloride polymer production method using the suspension polymerization seed, the vinyl chloride polymerization seed is polymerized in the preliminary polymerization reactor prior to the main polymerization, the vinyl chloride polymerization seed is transferred to the polymerization reactor, and the chloride is introduced into the polymerization reactor. Since the suspension polymerization reaction with the vinyl monomer proceeds, it is possible to shorten the polymerization reaction time to significantly improve the polymerization productivity, to block the whiskey generated by the undissolved particles of the reactants and to improve the initial coloring property. In addition, when the specific polymerization conversion rate and the temperature difference between the prepolymerization and the main polymerization are satisfied in the present invention, not only the improvement effect but also the polydispersity of the polymer to be produced is improved, thereby improving workability.

Hereinafter, each step will be described in detail.

Step 1

Step 1 according to an embodiment of the present invention is to prepare a vinyl chloride polymerization seed using a prepolymerization reactor, specifically, by polymerizing the first vinyl chloride monomer in a prepolymerization reactor so that the polymerization conversion rate is 5 to 20%. A vinyl chloride polymerized seed is prepared. Step 1 may mean a prepolymerization step.

The vinyl chloride polymerization seed of step 1 may be prepared by a suspension polymerization method made in the presence of a polymerization initiator and a protective colloid preparation. In addition, the vinyl chloride polymerization seed is not dissolved in the vinyl chloride monomer (VCM), the size of the seed particles is 100 to 120 ㎛.

It is preferable to prepare a vinyl chloride polymerization seed by polymerizing the polymerization conversion rate to 5 to 20% using a prepolymerization reactor, but more preferably 5 to 15%, even more preferably, the polymerization conversion rate is 10 to It is preferred to polymerize to 15% to produce a vinyl chloride polymerized seed.

In the present invention, the polymerization conversion rate may be a value measured using a butane tracer equipped with gas chromatography. Specifically, the polymerization conversion curve according to the ratio of vinyl chloride monomer and butane over time under constant polymerization conditions is prepared for each polymerization condition, and the polymerization conversion rate according to the polymerization conditions may be measured based on this.

In the case of preparing the vinyl chloride polymerized seed so as to have a polymerization conversion ratio of less than the above range in step 1), the polymerization productivity can be increased because the polymerization of the polymerized seed is not sufficiently performed and the amount of polymerized seed introduced into the polymerization reactor is too small. In the case of producing a vinyl chloride polymerization seed so as to have a polymerization conversion ratio exceeding the above range, since the growth of the polymerization seed is made to some extent and the stability is increased, the unity / redispersion of the vinyl chloride monomer introduced in the polymerization reactor It is hard to occur, which makes it difficult to control the internal shape of the polymer particles and the molecular weight of the polymer, which makes it difficult to control polydispersity, porosity, average pore diameter, etc. Polymer production can be difficult. In addition, workability may also be degraded.

The polymerization of step 1) may be carried out at a polymerization temperature of the vinyl chloride polymer by a conventional suspension polymerization, specifically, the suspension polymerization is carried out at a temperature of 30 to 80 ℃, preferably at a temperature of 45 to 75 ℃ Can be. The temperature at the time of suspension polymerization can be suitably adjusted according to the desired degree of polymerization and polymerization time (productivity) within the said range. For example, in view of the degree of polymerization, the higher the degree of polymerization, the lower the temperature, and the lower the degree of polymerization, the higher the temperature.

In addition, the stirring speed during the suspension polymerization may be a speed generally used to prepare the vinyl chloride polymer, and may be adjusted according to the properties of the desired vinyl chloride polymer, the size of the reactor, and the shape and type of the stirrer. Therefore, although not particularly limited, for example, in one example of the present invention, the stirring speed in the reactor of 1m ³ may be less than 180 to 250 rpm.

Step 1) according to an embodiment of the present invention specifically includes preparing a reaction mixture by mixing a protective colloid preparation, a first vinyl chloride monomer and a polymerization initiator in the polymerization water. Herein, the first vinyl chloride monomer refers to a vinyl chloride monomer, and may be the same as the second vinyl chloride monomer, which will be described later, or a number may be specified to distinguish the order of input.

In this case, as the polymerization solvent, various kinds of polymerization water, such as distilled water or deionized water, may be used as the polymerization solvent, and deionized water may be preferably used. The temperature of the polymerization water may be appropriately selected in consideration of the temperature at which the suspension polymerization is performed, and the amount of the polymerization water may be appropriately used according to the polymerization conditions, for example, the total content of the polymerization water of steps 1) and 2) is 70 parts by weight or more may be used based on 100 parts by weight of the total of the first and second vinyl chloride monomers.

The protective colloid preparation maintains the stability of the vinyl chloride monomer in the manufacturing process of the vinyl chloride polymer, and the average particle diameter, apparent specific gravity (BD), particle size distribution, plasticizer absorption rate (CPA), etc. of the desired degree. It may be used for the purpose of obtaining the physical properties of the, as the protective colloid preparation, for example, a vinyl alcohol-based resin having a hydration degree of 30 to 90%, a viscosity of 4% aqueous solution at room temperature of 5 to 100 cps, methoxy group 15 And at least one selected from the group consisting of cellulose and an unsaturated organic acid having a viscosity of 2 to 40% by weight, 3 to 20% by weight of propyl group, and a viscosity of 2 to 20,000 cps measured at 23 ± 5 ° C., Preferably, the degree of hydration is 30 to 90%, the vinyl alcohol resin having a viscosity of 5 to 100 cps of 4% aqueous solution at room temperature, 15 to 40% by weight of methoxy group and hydroxide It may be a cellulose of 3 to 20% by weight and a viscosity of 10% to 20,000 cps of a 2% aqueous solution measured at room temperature (20 ± 5 ° C.), or a mixture thereof. At this time, the unit% of the degree of hydration can be interpreted as the weight%.

In addition, the total content of the protective colloid preparation of step 1) and step 2) may be 0.03 to 5.0 parts by weight, preferably 0.05 to 2.5 parts by weight, based on 100 parts by weight of the first and second vinyl chloride monomers in total. When the total amount of the protective colloid preparation is less than 0.03 parts by weight, droplet stability is lowered, and the particle size of the polymerized seed and the final polymerized vinyl chloride polymer may be excessively increased to cause whiskey, and when it exceeds 5.0 parts by weight, the fine particles There is a fear of lowering the initial colorability due to the increase of these.

Meanwhile, in one example of the present invention, the protective colloid preparation may include a mixture of two or more vinyl alcohol resins having different degrees of hydration, and for example, vinyl alcohol resins having a degree of hydration of more than 50% and 90% or less (high degree of water resin). ) And a mixture of vinyl alcohol-based resin (low degree of hydration resin) having a degree of hydration of 30% to 50%.

In addition, the protective colloid preparation may be one containing the cellulose in addition to the vinyl alcohol-based resin, wherein the total content of the cellulose is 0.001 to 0.5 parts by weight based on a total of 100 parts by weight of the first and second vinyl chloride monomer It may be included in an amount, the cellulose may be methyl cellulose, hydroxyethyl cellulose, or hydroxypropyl methyl cellulose, and the like, any one or a mixture of two or more thereof may be used. Among these, hydroxypropyl methyl cellulose may be used. More specifically, the cellulose may have a methoxy group of 15 to 40 wt%, a propyl hydroxide group of 3 to 20 wt%, and a viscosity of 2% aqueous solution measured at 20 ± 5 ° C. To 20,000 cps.

The unsaturated organic acid polymer may include an acrylic acid polymer, a methacrylic acid polymer, an itaconic acid polymer, a fumaric acid polymer, a maleic acid polymer, or a succinic acid polymer, and any one or a mixture of two or more thereof may be used.

In addition, the total content of the polymerization initiator of step 1) and step 2) according to an embodiment of the present invention is used from 0.02 to 0.2 parts by weight based on 100 parts by weight of the total of the first and second vinyl chloride monomer used in the polymerization. Can be. Specifically, the polymerization initiator may be used at 0.03 parts by weight to 0.12 parts by weight based on 100 parts by weight of the total of the first and second vinyl chloride monomers. If the total content of the polymerization initiator is less than 0.02 parts by weight, the polymerization reaction time is long, the conversion rate to the vinyl chloride polymer is lowered, and the productivity may be lowered. If the content is more than 0.2 parts by weight, the polymerization initiator is not completely consumed during the polymerization process. However, it may remain in the finally prepared vinyl chloride polymer, thereby degrading thermal stability and color quality of the polymer.

The polymerization initiator is not particularly limited, but for example, diacyl peroxide initiators such as dicumyl peroxide, dipentyl peroxide, di-3,5,5-trimethylhexanoyl peroxide, dilauroyl peroxide, Peroxydicarbonate initiators such as diisopropyl peroxydicarbonate, di-sec-butylperoxydicarbonate, di-2-ethylhexyl peroxydicarbonate, cumyl peroxydicarbonate, t-butylperoxy neodecanoate, t- Butyl peroxy neoheptanoate, t-amyl peroxy neodecanoate, cumyl peroxy neodecanoate, cumyl peroxy neoheptanoate, 1,1,3,3-tetramethylbutyl peroxy neodecano Peroxy ester-based initiators such as ate and hydroxy-dimethylbutyl peroxy ester, azo compounds such as azobis-2,4-dimethylvaleronitrile, sulfes such as potassium persulfate and ammonium persulfate There may be mentioned teugye initiator, etc., it may be used by these alone or in combination of two or more.

Method for producing a vinyl chloride polymer according to an embodiment of the present invention may include stirring the reaction mixture prepared above may be suspended polymerization through the stirring.

In addition, the vinyl chloride polymer production method according to an embodiment of the present invention, if necessary, sodium bicarbonate (NaHCO ₃ ), sodium borate (Na ₂ B ₄ O ₇ ), dibasic sodium phosphate (Na ₂ HPO) as a hydrogen ion concentration regulator. ₄ ), sodium carbonate (Na ₂ CO ₃ ), potassium dihydrogen phosphate (KH ₂ PO ₄ ), ammonium hydroxide (NH ₄ OH), potassium tartarate (KHC ₄ H ₄ O ₆ ), potassium hydrogen phthalate (KHC ₈ H ₄ O ₄ ) or calcium hydroxide (Ca (OH) ₂ ) or a mixture of two or more thereof.

In addition, the vinyl chloride polymer production method according to an embodiment of the present invention is a diaryl maleate (DAM, DiAllyl Maleate), diaryl phthalate (DAP, DiAllyl Phthalate), ethyl glycol dimethyl acrylate as necessary (EGDMA, Ethyl Glycol DiMethyl Acrylate) or triaryl isocyanurate (TAIC, TriAllyl Isocyanurate), or may further include a mixture of two or more thereof.

In addition, at any point in the specific polymerization conversion range in step 1), all of the produced vinyl chloride polymerized seed and unreacted monomer may be transferred to the present polymerization reactor to proceed with the main polymerization.

Step 2

Step 2) according to an embodiment of the present invention is a step of preparing a vinyl chloride polymer through the present polymerization using the vinyl chloride polymerization seed prepared in step 1), specifically, the vinyl chloride polymerization of step 1) The seed may be transferred to the present polymerization reactor, and polymerized with a second vinyl chloride monomer introduced into the present polymerization reactor to prepare a vinyl chloride polymer. In addition, step 2) may mean the present polymerization step. In addition, the vinyl chloride polymer prepared after the step 2) may be a homopolymer.

That is, in step 2), the vinyl chloride polymerization seed of step 1) is transferred to the polymerization reactor, and the vinyl chloride polymer is polymerized by polymerizing the second vinyl chloride monomer and the transferred vinyl chloride polymerization seed introduced into the polymerization reactor. It may be to prepare.

According to an embodiment of the present invention, a method for preparing a vinyl chloride polymer may improve polymerization productivity due to excellent compatibility between monomers compared to a process for preparing a copolymer as a vinyl chloride homopolymer is produced.

In addition, in the case of the copolymer, it is not easy to control the degree of polymerization because the structure and properties of the entire polymer may vary depending on the type and content ratio of the comonomer copolymerized with the vinyl chloride monomer. In this method, there is a problem in that it is difficult to ensure the reliability of the polymerization degree measured, and thus the exact degree of polymerization cannot be measured. In addition, when blending with a resin composition, the physical properties vary greatly depending on the type and content ratio of the comonomer as described above, and thus, it is difficult to control the quality of the molded article and the like because it is difficult to predict the blending properties compared to the homopolymer. Accordingly, the vinyl chloride polymer of the present invention is characterized by ensuring excellent polymerization productivity and blendability while alleviating all the problems of the copolymer by specifying the vinyl chloride homopolymer.

According to one embodiment of the present invention, the order of the time of transferring the vinyl chloride polymerization seed prepared in step 1) and the time of adding the second vinyl chloride monomer to the polymerization reactor is not particularly limited. The vinyl chloride polymerization seed may be transferred to the polymerization reactor with the second vinyl chloride monomer filled in the polymerization reactor, or the second chloride may be transferred to the polymerization reactor after transferring the vinyl chloride polymerization seed to the polymerization reactor. Vinyl monomers can also be added. As another example, the transfer of the vinyl chloride polymerization seed and the introduction of the second vinyl chloride monomer into the polymerization reactor may be simultaneously performed.

In step 2), the suspension polymerization method described above in step 1) may be applied in the same manner. Specifically, in addition to the vinyl chloride polymerization seed transferred in step 1), suspension polymerization may be performed in the presence of a protective colloid preparation and a polymerization initiator. have. At this time, the protective colloid preparation and the polymerization initiator may be introduced into the polymerization reactor at the same time as the second vinyl chloride monomer, or introduced into the polymerization reactor before the second vinyl chloride monomer. In addition, the protective colloid preparation and the polymerization initiator may be selected from the protective colloid preparation and the polymerization initiator of the kind described above in step 1), the protective colloid preparation and polymerization initiator applied in the step 2) in the step 1) It may be the same as or different from the protective colloid preparation and the polymerization initiator. In addition, in step 2), the polymerization water described above in step 1) may be further included in the reaction mixture, and a hydrogen ion concentration regulator and a crosslinking agent may be further added as necessary. In this case, the polymerization water, the hydrogen ion concentration regulator and the crosslinking agent applied in step 2) may be the same as or different from the polymerization water, the hydrogen ion concentration regulator and the crosslinking agent in step 1).

In addition, the polymerization temperature of step 2) may be a temperature having a difference of 5 to 15 ℃ from the polymerization temperature of step 1), preferably the difference between the polymerization temperature of step 1) and step 2) is 10 to 15 ℃ Can be. When the difference in polymerization temperature of steps 1) and 2) satisfies 5 to 15 ° C., a vinyl chloride polymer having a polydispersity of 2.0 to 2.3 can be prepared, and the vinyl chloride polymer has the polydispersity. The workability is improved.

In addition, the polymerization temperature of the step 1) and step 2) is not particularly limited to the step 1) is higher or lower than the step 2), if the temperature difference of the above-described range, the aspect of improving the physical properties of the produced vinyl chloride polymer In step 2), the polymerization temperature of step 2) may be adjusted higher than the polymerization temperature of step 1), but considering the polymerization productivity and shortening of the polymerization time, it is preferable that the polymerization temperature of step 1) is higher than that of step 2). In addition, the above-mentioned first vinyl chloride monomer and second vinyl chloride monomer are terms used to distinguish the order of input, and in order to prepare a vinyl chloride homopolymer, the first vinyl chloride monomer and the second vinyl chloride monomer have the same vinyl chloride monomer. Is preferably.

In addition, the second vinyl chloride monomer of step 2) may have a higher content than the first vinyl chloride monomer of step 1), and the weight ratio of the first vinyl chloride monomer and the second vinyl chloride monomer may be 1: 1.2 to 1:10, preferably 1: 2 to 1: 8.

Furthermore, step 2) of the method for preparing a vinyl chloride polymer according to an embodiment of the present invention may further include terminating the polymerization and recovering a product (vinyl chloride polymer).

In this case, the suspension polymerization may terminate the polymerization by the addition of a reaction terminator, the termination point is the time when the pressure in the reactor is 6 kgf / cm ² to 8 kgf / cm ² (or polymerization conversion exceeds 85%) ).

The reaction terminator is not particularly limited, but may be, for example, a phenol compound, an amine compound, a nitrile compound, a sulfur compound, or the like. Specifically, the reaction terminator is triethylene glycol-bis-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate, hydroquinone, p-methoxyphenol, t-butylhydro Roxyanisole, n-octadecyl-3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, 2,5-di-t-butyl hydroquinone, 4,4'-part Phenolic compounds such as thilidenebis (3-methyl-6-t-butyl phenol), t-butyl catechol, 4,4'-thiobis (6-t-butyl-m-cresol), tocophenol, N, Amine compounds such as N'-diphenyl-p-phenylenediamine, 4,4'-bis (dimethylbenzyl) diphenyl amine, 2-phenyl nitronylnitroxide, 3-imida 3-imidazoline nitroxide, 4-hydroxy-2,2 ', 6,6'-tetramethyl-piperidine-1-oxyl (4-hydroxy-2,2', 6,6 ' nitrile compounds such as -tetramethyl-piperidine-1-oxyl), sulfur compounds such as dodecyl mercaptan and 1,2-diphenyl-2-thiol, triphenylphosphite, diphenylde It may be one or more selected from phosphoric acid compounds such as sil phosphite, phenylisodecyl phosphite, tri (nonylphenyl) phosphite, and trilauryl trithiophosphite, preferably triethylene glycol-bis-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate.

The vinyl chloride polymer prepared according to the polymerization stop may be in the form of a slurry, and the slurry may be prepared in the form of the final vinyl chloride polymer by removing moisture with a fluidized bed dryer under ordinary reaction conditions.

In addition, the polymerization of the steps 1) and 2) may further include additives such as polymerization regulators, chain transfer agents, pH regulators, antioxidants, crosslinking agents, antistatic agents, antiscalants, surfactants, etc. It may be added, the type and content of the additive is not particularly limited and may be used in conventional types and contents known in the art. The additive may be added at any time during suspension polymerization, during polymerization or after polymerization, or may be added in batches or continuously.

The reactor used in the present invention is not particularly limited in the shape of the stirring device such as a stirrer and baffle, and a stirring device generally used for suspension polymerization of a vinyl chloride polymer can be used. Specific examples of the stirrer include stirring paddles, paddle paddles, pitched paddle pads, bloomers gin pads, pudora rams, turbine pads, propeller pads, or the like. Stirrers combined with more than one stirring blade may be used, and baffles may be plate-shaped, cylindrical, D-shaped, looped, or finger-type.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the following Examples and Experimental Examples are provided to illustrate the present invention and the scope of the present invention is not limited thereto.

Example 1

60 g of polyvinyl alcohol having a viscosity of 30 cps in a 4% aqueous solution at room temperature of 90 kg of deionized water, 45 g of hydroxy-dimethylbutyl peroxy ester, 80% of hydration in a reactor having a internal volume of 0.2 m3 (preliminary polymerization reactor) 40 g of polyvinyl alcohol having a viscosity of 20 cps in a 4% aqueous solution at room temperature was charged into a reactor, and vacuum was applied. Then, 75 kg of vinyl chloride monomer was added and the polymerization temperature was raised to 62 ° C. to proceed with the polymerization reaction. The vinyl chloride polymerized seed and the unreacted monomer produced at the time of 13% (13 ± 2%) polymerization conversion are transferred to the present polymerization reactor. At this time, the polymerization conversion was measured using a butane tracer equipped with gas chromatography. The polymerization conversion curve according to the ratio of vinyl chloride monomer and butane over time under constant polymerization conditions is prepared for each polymerization condition, and the polymerization conversion rate according to the polymerization conditions can be measured based on this.

Into a reactor having a reflux condenser of 1 m 3 (main polymerization reactor), 360 kg of deionized water, 60 g of cumylperoxydicarbonate and 120 g of t-butylperoxy neodecanoate were added, and the degree of hydration was 80%. 150 g of polyvinyl alcohol having a viscosity of 30% cps, 40% hydration, 120 g of polyvinyl alcohol having a viscosity of 4 cps at room temperature, and 120 g of polyvinyl alcohol having a viscosity of 20 cps, and a 2% aqueous solution measured at room temperature 30 g of hydroxypropylmethyl cellulose having a viscosity of 100 pcs was added, followed by vacuum, and then 300 kg of vinyl chloride monomer was added thereto.

After the completion of the transfer of the vinyl chloride polymerization seed and the unreacted monomer from the prepolymerization reactor, the polymerization reaction temperature was adjusted to 57 ° C. to maintain the reaction during the entire polymerization process, and triethylene was reached when the polymerization reactor pressure reached 6.5 kgf / cm 2. After adding 60 g of glycol-bis-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate (antioxidant), unreacted monomer was recovered and the polymer slurry was recovered in the polymerization reactor. At the end of the polymerization, the polymerization conversion was 84% (84 ± 2%). The slurry thus obtained was dried in a fluidized bed dryer in a conventional manner to obtain a vinyl chloride polymer.

Example 2

The polymerization reaction was carried out by raising the polymerization reaction temperature of the prepolymerization reactor to 67 ° C., and the polymerization reaction was carried out by adjusting the polymerization reaction temperature of the present polymerization reactor to 56 ° C., and then the polymerization reactor pressure reached 6.3 kgf / cm 2 ( Polymerization conversion was carried out in the same manner as in Example 1 except that the polymerization reaction was terminated at 84% (84 ± 2%)) to obtain a vinyl chloride polymer.

Example 3

The polymerization reaction was carried out by raising the polymerization reaction temperature of the prepolymerization reactor to 70 ° C., and the polymerization reaction was carried out by adjusting the polymerization reaction temperature of the present polymerization reactor to 55.5 ° C., and then the polymerization reactor pressure reached 6.2 kgf / cm 2 ( Polymerization conversion was carried out in the same manner as in Example 1 except that the polymerization reaction was terminated at 84% (84 ± 2%)) to obtain a vinyl chloride polymer.

Example 4

The polymerization reaction was carried out by raising the polymerization reaction temperature of the preliminary polymerization reactor to 67 ° C., and both the vinyl chloride polymer seed and the unreacted monomer prepared at the time when the polymerization conversion was 7% (7 ± 2%) were transferred to the polymerization reactor. After the polymerization reaction was carried out by adjusting the polymerization reaction temperature of the polymerization reactor to 57 ° C., the polymerization reaction was carried out when the polymerization reactor pressure reached 6.5 kgf / cm 2 (the polymerization conversion rate was 84% (84 ± 2%)). Except that was terminated in the same manner as in Example 1 to give a vinyl chloride polymer.

Example 5

The polymerization reaction was carried out by raising the polymerization reaction temperature of the preliminary polymerization reactor to 68 ° C., and both the vinyl chloride polymer seed and the unreacted monomer prepared at a polymerization conversion rate of 18% (18 ± 2%) were transferred to the polymerization reactor. After the polymerization reaction was carried out by adjusting the polymerization reaction temperature of the polymerization reactor to 54.5 ° C., the polymerization reaction was performed at the time when the polymerization reactor pressure reached 6.0 kgf / cm 2 (the polymerization conversion rate was 84% (84 ± 2%)). Except that was terminated in the same manner as in Example 1 to give a vinyl chloride polymer.

Example 6

The polymerization reaction was carried out by raising the polymerization reaction temperature of the preliminary polymerization reactor to 54.5 ° C., and both the vinyl chloride polymer seed and the unreacted monomer prepared at a polymerization conversion rate of 13% (13 ± 2%) were transferred to the polymerization reactor. After the polymerization reaction was carried out by adjusting the polymerization reaction temperature of the polymerization reactor to 60 ° C., the polymerization reaction was carried out when the polymerization reactor pressure reached 7.0 kgf / cm 2 (the polymerization conversion rate was 84% (84 ± 2%)). Except that was terminated in the same manner as in Example 1 to give a vinyl chloride polymer.

Comparative Example 1

Deionized water 360kg, cumylperoxydicarbonate 60g, t-butylperoxy neodecanoate 120g were added to a reactor having a reflux condenser with a volume of 1m 3, the degree of hydration was 80% and the viscosity of a 4% aqueous solution at room temperature 150 g of polyvinyl alcohol of 30 cps, 40% of hydration, 120 g of polyvinyl alcohol of 20 cps with a viscosity of 4% aqueous solution at room temperature, hydroxy group having a viscosity of 100 pcs of 2% aqueous solution measured at room temperature with 10% by weight of propyl hydroxide. 30 g of propylmethyl cellulose was added to the reactor, and vacuum was added, followed by 300 kg of vinyl chloride monomer. The polymerization reaction is carried out while maintaining the temperature of the polymerization reaction at 57 ° C. for the entire polymerization process. 4-hydroxy-2,2,6,6-tetramethyl-piperidine- as a reaction terminator when the polymerization reactor pressure reached 6.5 kgf / cm 2 (polymerization conversion rate was 84% (84 ± 2%)). 15 g of 1-oxyl and 60 g of triethylene glycol-bis-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate were added, then unreacted monomers were recovered and the polymer slurry was recovered in the polymerization reactor. It was. The slurry thus obtained was dried in a fluidized bed dryer in a conventional manner to obtain a vinyl chloride polymer.

Comparative Example 2

Into a reactor with a reflux condenser, 450 kg of deionized water, 75 g of cumylperoxy dicarbonate and 150 g of t-butylperoxy neodecanoate were added to the reactor having a reflux condenser, the degree of hydration was 80%, and the viscosity of the 4% aqueous solution at room temperature 188 g of polyvinyl alcohol with 30 cps, 40% hydration, 150 g of polyvinyl alcohol with a viscosity of 4 cps at room temperature and 150 g of polyvinyl alcohol with 20 cps, hydroxypropyl with a viscosity of 100 pcs of 2% aqueous solution measured at room temperature 37 g of methyl cellulose was added to the reactor, and vacuum was added, followed by 375 kg of vinyl chloride monomer. The polymerization reaction was carried out while maintaining the temperature of the polymerization reaction at 57 DEG C while maintaining the whole polymerization reaction. 4-hydroxy-2,2,6,6-tetramethyl-piperidine- as a reaction terminator when the polymerization reactor pressure reached 6.5 kgf / cm 2 (polymerization conversion rate was 84% (84 ± 2%)). 15 g of 1-oxyl and 75 g of triethylene glycol-bis-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate were added, and then the unreacted monomers were recovered and the polymer slurry was recovered in the polymerization reactor. It was. The slurry thus obtained was dried in a fluidized bed dryer in a conventional manner to obtain a vinyl chloride polymer.

Comparative Example 3

The polymerization reaction was carried out by raising the polymerization reaction temperature of the preliminary polymerization reactor to 60 ° C., and both the vinyl chloride polymer seed and the unreacted monomer prepared at the time when the polymerization conversion was 3% (3 ± 1%) were transferred to the polymerization reactor. After the polymerization reaction was carried out by adjusting the polymerization reaction temperature of the polymerization reactor to 57 ° C., the polymerization reaction was carried out when the polymerization reactor pressure reached 6.5 kgf / cm 2 (the polymerization conversion rate was 84% (84 ± 2%)). Except that was terminated in the same manner as in Example 1 to give a vinyl chloride polymer.

Comparative Example 4

The polymerization reaction was carried out by raising the polymerization reaction temperature of the preliminary polymerization reactor to 65 ° C., and both the vinyl chloride polymer seed and the unreacted monomer prepared at the time when the polymerization conversion was 25% (25 ± 2%) were transferred to the polymerization reactor. After the polymerization reaction was carried out by adjusting the polymerization reaction temperature of the polymerization reactor to 56 ° C., the polymerization reaction was carried out at the time when the polymerization reactor pressure reached 6.3 kgf / cm 2 (the polymerization conversion rate was 84% (84 ± 2%)). Except that was terminated in the same manner as in Example 1 to give a vinyl chloride polymer.

Comparative Example 5

The polymerization reaction was carried out by raising the polymerization reaction temperature of the preliminary polymerization reactor to 69 ° C., and both the vinyl chloride polymer seed and the unreacted monomer prepared at the time when the polymerization conversion was 18% (18 ± 2%) were transferred to the polymerization reactor. After the polymerization reaction was carried out by adjusting the polymerization reaction temperature of the polymerization reactor to 52 ° C., the polymerization reaction was carried out at the time when the polymerization reactor pressure reached 5.7 kgf / cm 2 (the polymerization conversion rate was 84% (84 ± 2%)). Except that was terminated in the same manner as in Example 1 to give a vinyl chloride polymer.

Comparative Example 6

Example 1 except that the polymerization temperature was raised to 57 ° C. in the prepolymerization reactor, and the polymerization reaction was terminated at the time of reaching 6.5 kgf / cm 2 (polymerization conversion rate of 84% (84 ± 2%)) in the present polymerization. The vinyl chloride polymer was obtained by the same method as described above.

Comparative Example 7

80 kg of deionized water was added to a 0.2 m ³ reactor equipped with a reflux condenser, 25 g of polyvinyl alcohol with 80% hydration, 20 g of polyvinyl alcohol with 42% hydration, and 5 g of hydroxypropylmethyl cellulose. Into the reactor, 34 kg of a mixture of di (2-ethylhexyl) maleate and di (2-ethylhexyl) fumarate (weight ratio = 95: 5) together with 50 kg of vinyl chloride monomer was added, followed by di-2-. 30 g of ethylhexyl peroxy dicarbonate was added to initiate the reaction. The reaction was carried out while maintaining the reaction at 57 ° C. during the entire polymerization process, and the reaction product and the unreacted monomer were both transferred to the secondary polymerization reactor at a polymerization conversion rate of 15% (15 ± 2%).

In the de-ionized water 360kg to the interior volume reactor of 1m ³ having a reflux condenser and a moisture content of 80% polyvinyl alcohol 150g, polyvinyl alcohol moisture content is 42% 120g, and hydroxypropyl methyl cellulose 30g to the reactor After adding the vinyl chloride monomer 300 kg, 60 g of dicumyl peroxide and 120 g of t-butyl peroxy neodecanoate were added to initiate the reaction.

The reaction was carried out while maintaining the temperature at 50 ° C. during the entire polymerization reaction, and when the polymerization reactor pressure reached 6.0 kgf / cm ² (the polymerization conversion rate was 84% (84 ± 2%)), 4- 5 g of hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl, triethylene glycol-bis-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate After the addition of 35g of unreacted monomer was isolated and recovered, the produced copolymer was recovered from the polymerization reactor, and then dried in a fluidized bed dryer to obtain a copolymer.

The polymerization conditions of the preliminary polymerization and the main polymerization of Examples 1 to 6 and Comparative Examples 1 to 7 are summarized in Table 1 below.

		Monomer (polymer)	Prepolymerization Conversion Rate (%)	Prepolymerization Temperature (℃)	Main polymerization temperature (℃)
Example	One	Vinyl chloride (homopolymer)	13 (13 ± 2)	62	57
	2	Vinyl chloride (homopolymer)	13 (13 ± 2)	67	56
	3	Vinyl chloride (homopolymer)	13 (13 ± 2)	70	55.5
	4	Vinyl chloride (homopolymer)	7 (7 ± 2)	67	57
	5	Vinyl chloride (homopolymer)	18 (18 ± 2)	68	54.5
	6	Vinyl chloride (homopolymer)	13 (13 ± 2)	54.5	60
Comparative example	One	Vinyl chloride (homopolymer)	-(Single reaction)	-	57
	2	Vinyl chloride (homopolymer)	-(Single reaction)	-	57
	3	Vinyl chloride (homopolymer)	3 (3 ± 1)	60	57
	4	Vinyl chloride (homopolymer)	25 (25 ± 2)	65	56
	5	Vinyl chloride (homopolymer)	18 (18 ± 2)	69	52
	6	Vinyl chloride (homopolymer)	13 (13 ± 2)	57	57
	7	Vinyl chloride, di (2-ethylhexyl) maleate and di (2-ethylhexyl) fumalate (copolymer)	15 (15 ± 2)	57	50

Here, the prepolymerization conversion rate (%) means the polymerization conversion rate in the prepolymerization reaction immediately before transferring to the present polymerization reactor.

Experimental Example 1 Evaluation of Polymerization Productivity and Polymer Properties

1) Evaluation of Polymerization Productivity

In order to evaluate the polymerization productivity of the vinyl chloride polymers of Examples 1 to 6 and Comparative Examples 1 to 7, the output of the PVC polymer produced per hour in batches was measured, and the results are shown in Table 1 below.

2) Determination of polymerization degree

It was measured by ASTM D1243-79.

3) Molecular weight measurement

The weight average molecular weight (Mw), the number average molecular weight (Mn), and the polydispersity were measured for the vinyl chloride polymers prepared in Examples 1 to 6 and Comparative Examples 1 to 7, respectively. Specifically, 0.02 g of a vinyl chloride polymer sample was added to 20 ml of tetrahydrofuran (THF), dissolved for 24 hours, and filtered through a 0.45 um filter, followed by a GPC device (Waters 2414 Refractive Index Detector, Waters 1525 Binary HPLC Pump, and Waters 717 Autosampler, Waters, Inc.). After measurement at 25 ℃ and normal pressure (1 atm), use standard sample (Styrene standard molecular weight (g / mol) 1320, 2750, 6760, 19700, 50600, 124000, 279000, 768000, 1540000, 2350000) After drawing the calibration curve, Mw and Mn were determined, respectively, and polydispersity was determined from the ratio of Mw / Mn. The results are shown in Table 2 below.

4) Pore property measurement

The pore physical properties of the vinyl chloride polymers prepared in Examples 1 to 6 and Comparative Examples 1 to 7 were measured by mercury porosimetry. Specifically, the surface pores (Pinter) from the amount of mercury infiltrated into the vinyl chloride polymer particles using a mercury porosity analyzer (Auto Pore IV 9520, manufactured by Micromeritics) under normal temperature (23 ± 2 ° C) and atmospheric pressure (1atm) conditions Accessible intravoid (Pacc) and inaccessible intravoid (Pinacc) were measured, respectively, and the average pore diameter (4V / A) and porosity were calculated from the results, and the results are shown in Table 2 below. Indicated. In this case, the porosity represents a percentage with respect to the volume.

		Polymerization time (min)	Polymerization output per unit time		Degree of polymerization	Molecular Weight (Mn, Mw: g / mol)			Average pore diameter (nm)	Porosity (%)
			kg / day	MT / year		Mn	Mw	PDI
Example	One	220	2048	748	1028	74014	153648	2.08	324.3	61.11
	2	215	2096	765	1032	73233	155914	2.13	345.4	67.80
	3	212	2125	776	1030	72082	161535	2.24	415.3	65.29
	4	220	2042	746	1033	73755	158190	2.15	308.3	63.28
	5	205	2202	804	1035	73126	160684	2.20	363.6	60.54
	6	235	1917	700	1024	73315	151127	2.06	312.6	61.94
Comparative example	One	270	1328	485	1032	75019	135296	1.80	248.6	55.59
	2	280	1601	584	1030	74868	139081	1.86	255.4	56.07
	3	262	1713	625	1028	72793	141528	1.94	288.9	58.59
	4	220	2058	751	1034	72251	152657	2.11	334.4	51.63
	5	210	2150	785	1032	70220	167411	2.38	310.4	56.07
	6	240	1878	685	1030	74263	137355	1.85	251.3	56.02
	7	360	1229	449	-	84386	163038	1.93	27.6	17.43

As shown in Table 2, Examples 1 to 6 by applying a seed suspension polymerization method using a vinyl chloride polymerization seed and controlling the difference in polymerization conversion rate and each polymerization reaction temperature in preparing a polymerization seed within a specific range are Comparative Example 1 Compared to 7 to 7, the reaction time is shortened at the same conversion rate, and the polymerization yield per unit time is improved, and the average pore diameter and porosity of the polymer to be produced have a larger value, in particular, a porosity of 60% or more can be obtained. We can confirm that we can. In addition, it can be confirmed that the polydispersity (PDI) is in the range of 2.0 to 2.3.

Specifically, Comparative Examples 1 and 2, which do not apply seed polymerization, and a polymerization seed having a polymerization conversion ratio outside the numerical range of the present invention are prepared, and the polymerization temperature of the prepolymerization and the main polymerization is also outside the specific numerical range in the present invention. In Example 3, it can be seen that the polymerization yield is significantly lower than that of Examples 1 to 6, and the polydispersity is less than 2.0, thereby deviating from the physical properties of a specific polymer in the present invention. In addition, looking at the pore characteristics in the polymer, it can be seen that the average pore diameter also has a small value compared to Examples 1 to 6, the porosity has a low value of less than 60%.

In addition, the seed polymerization was applied in the same manner as in the present invention, but in Comparative Example 4 in which the polymerization conversion rate of the seeds was outside the numerical range of the present invention, the polymerization yield, the polydispersity, and the average pore diameter were maintained at a similar level to the present invention. It can be seen that the porosity of the polymer has a low value of less than 60%, Comparative Example 5 in which the temperature difference between the preliminary polymerization and the main polymerization is outside the numerical range of the present invention is the polymerization yield, the average pore diameter is similar to the present invention It is maintained, but the polydispersity exceeds 2.0 and out of the scope of the present invention, it can be confirmed that the porosity also has a low value of less than 60%.

In addition, although the seed polymerization rate was the same numerical range as in Example, Comparative Example 6 in which the prepolymerization and the polymerization temperature of the main polymerization were kept the same, the productivity improvement effect was insignificant compared to Examples 1 to 6, and the porosity was less than 60%. And, polydispersity also has a value of less than 2.0 it can be confirmed that the desired level is not reached, the difference in polymerization conversion and pre-polymerization and polymerization temperature of the present polymerization is the same level as in Example, but the copolymer is not homopolymer The prepared Comparative Example 7 can be confirmed that the average pore diameter and porosity can not meet the physical properties according to an embodiment of the present invention under the influence of the comonomer, polydispersity is also confirmed to have a low value of less than 2.0. have. In particular, Comparative Example 7 has a higher polymerization time compared to Examples 1 to 6, it can be confirmed that the polymerization yield per unit time is significantly lower. In addition, Comparative Example 7 has a problem that it is difficult to measure the degree of polymerization degree of reliability as it is a copolymer using two kinds of monomers.

Experimental Example 2: Evaluation of Blending Properties of Polymer

1) Initial colorability evaluation

To evaluate the initial coloring properties of the vinyl chloride polymers of Examples 1 to 6 and Comparative Examples 1 to 6, 1 part by weight of a tin stabilizer, 0.5 part by weight of a lead stabilizer, and a stabilizer based on 100 parts by weight of the vinyl chloride polymer of each Example and Comparative Example. 1.5 weight part and 45 weight part of plasticizers (DOP) were mix | blended, and it knead | mixed for 5 minutes at 150 degreeC using the roll, and the sheet was obtained. This sheet was cut and stacked, and a press sheet was obtained by press molding. In Comparative Example 7, a compressed sheet was obtained by blending, kneading and compressing in the same manner as described above except that 45 parts by weight of a plasticizer was added. This was visually observed and evaluated, and the results are shown in Table 2 below.

(Double-circle): It is the level of coloring similar to this compared with the comparative example 1, and a level which is satisfactory practically.

(Circle): It is a color degree of the grade which is slightly inferior compared with the comparative example 1, and there is no abnormality, and is a level which is satisfactory practically.

X: The level of coloring differs clearly compared with the comparative example 1, and the level which has a problem practically.

2) Fish-eye sheep

To 100 parts by weight of the vinyl chloride polymer of Examples 1 to 6 and Comparative Examples 1 to 6, 45 parts by weight of a plasticizer (DOP), 0.1 part by weight of barium stearate, 0.2 part by weight of a tin stabilizer, and 0.1 part by weight of carbon black at 140 ° C. After mixing and kneading for 6 minutes using an inch roll, a sheet having a thickness of 0.3 mm was made and represented by the number of white transparent particles in 100 cm 2 of this sheet, and the results are shown in Table 2 below. In addition, the vinyl chloride copolymer of Comparative Example 7 was prepared in the same manner as described above except that 45 parts by weight of a plasticizer (DOP) was added to measure the amount of whiskey.

3) Melt viscosity measurement (processability evaluation)

45 parts by weight of a plasticizer (DOP) was added to 100 parts by weight of each of the vinyl chloride polymers of Examples 1 to 6 and Comparative Examples 1 to 6, and a melt viscosity was obtained using a capillary rheometer (RHEO-TESTER 2000, GOTTFERT Co., Ltd.). Was measured, and the results are shown in Table 3 below. In Comparative Example 7, the melt viscosity was measured without blending the plasticizer with the vinyl chloride copolymer.

		Fusisia	Initial coloring	Melt Viscosity (Pas)
				shear rate (1 / s)
				100	200	300	400	500	600	700	800	1000
Example	One	3	◎	775.31	606.63	511.2	382.55	331.23	268.28	246.72	224.68	188.85
	2	4	◎	706.34	512.51	437.67	342.25	309.07	266.78	226.45	221.54	162.83
	3	2	○	648.25	502.65	381.9	303.24	231.48	206.44	164.17	142.69	122.11
	4	3	◎	740.35	576.47	453.21	350.83	300.55	251.23	512.54	176.64	154.72
	5	4	○	681.22	520.81	431.33	326.72	280.13	230.24	193.77	156.29	138.32
	6	4	◎	742.64	596.38	493.45	372.59	321.87	264.58	240.32	220.06	177.73
Comparative example	One	5	◎	916.38	655.36	571.78	441.18	367.59	314.93	283.62	257.65	218.62
	2	6	○	938.41	659.14	576.09	450.92	375.62	330.68	295.08	273.96	245.72
	3	5	○	865.72	632.14	544.92	414.56	337.35	282.15	248.64	233.6	203.42
	4	20	X	757.57	592.41	491.74	393.39	301.34	268.21	214.71	188.64	161.02
	5	16	X	723.03	568.45	451.23	360.87	283.99	248.35	189.95	159.53	143.17
	6	2	◎	875.43	649.66	518.72	432.51	356.84	290.37	247.65	231.14	205.08
	7	2	○	718.25	612.51	537.67	442.25	409.07	366.78	326.45	321.54	262.83

As shown in Table 3, Examples 1 to 6 by applying a seed suspension polymerization method using a vinyl chloride polymerization seed, and controlling the difference in polymerization conversion rate and each polymerization reaction temperature in the preparation of the polymerization seed within a specific range is Comparative Example 1 Since the number of Fuchsia has a significantly smaller value than to 7, it can be seen that the quality of the Fuchsia (protrusion quality) is improved, it can be seen that the initial colorability is also expressed at an excellent level. In addition, Examples 1 to 6 can confirm that the melt viscosity is lower than Comparative Examples 1 to 3, 6 and 7, but a low melt viscosity means that the flowability is good, indicating that it can have excellent workability It is an indicator. Therefore, Examples 1 to 6 it can be confirmed that the workability is improved compared to Comparative Examples 1 to 3, 6 and 7.

On the other hand, Comparative Examples 4 and 5, but the melt viscosity is similar to the present invention, the number of whiskeys is remarkably large, it can be confirmed that the quality is deteriorated to a level that is also problematic in practical use.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims (11)

1. Vinyl chloride polymer having a polydispersity (PDI) of 2.0 to 2.3 and a porosity of at least 60%.
2. The method of claim 1,

   The vinyl chloride polymer is an average pore diameter (Average pore diameter, 4V / A) is a vinyl chloride polymer of 300 nm or more.
3. The method of claim 1,

   The porosity of the vinyl chloride polymer is 60 to 75% of the vinyl chloride polymer.
4. The method of claim 1,

   The average pore diameter of the vinyl chloride polymer is 300 to 600 nm.
5. The method of claim 1,

   The vinyl chloride polymer is a vinyl chloride polymer homopolymer (homopolymer).
6. Preparing a vinyl chloride polymerization seed by polymerizing the first vinyl chloride monomer in a prepolymerization reactor such that the polymerization conversion rate is 5 to 20% (step 1); And

   And transferring the vinyl chloride polymerization seed to the polymerization reactor and polymerizing with the second vinyl chloride monomer introduced into the polymerization reactor to prepare a vinyl chloride polymer (step 2).

   The difference between the polymerization temperature of step 1 and step 2 is 5 to 15 ℃,

   Wherein said vinyl chloride polymer is a vinyl chloride homopolymer.
7. The method of claim 6,

   The polymerization of step 1 and step 2 is a suspension polymerization,

   The suspension polymerization is carried out in the presence of a protective colloid preparation and a polymerization initiator.
8. The method of claim 6,

   The difference in the polymerization temperature of step 1 and step 2 is a method of producing a vinyl chloride polymer that is 10 to 15 ℃.
9. The method of claim 6,

   The vinyl chloride polymerization seed is a method for producing a vinyl chloride polymer that is prepared by polymerization so that the polymerization conversion is 5 to 15%.
10. The method of claim 6,

    Method for producing a vinyl chloride polymer of the polymerization temperature of the step 1 is a higher temperature than the polymerization temperature of the step 2.
11. The method of claim 6,

    Wherein the first vinyl chloride monomer and the second vinyl chloride monomer are the same vinyl chloride monomers.