KR20190075346A - Vinyl chloride polymer and preparation method thereof - Google Patents

Abstract

The present invention relates to a vinyl chloride polymer, a preparation method thereof and plastisol comprising the same. A vinyl chloride polymer according to the present invention has a low moisture content based on the weight of the vinyl chloride polymer and contains the particle diameter within a specific range. When the vinyl chloride polymer is mixed with a plasticizer to prepare plastisol, prepared plastisol has low viscosity and a low time change rate, thereby having improved viscosity properties. In addition, provided is a method for preparing a vinyl chloride polymer.

Description

[0001] The present invention relates to a vinyl chloride polymer and a preparation method thereof,

The present invention relates to a vinyl chloride polymer and a method for producing the same.

The vinyl chloride polymer is a resin containing 50% or more of vinyl chloride. It is inexpensive, hardness is easy to control, and can be applied to most processing equipments. In addition, it can provide molded articles having excellent physical and chemical properties such as mechanical strength, weather resistance, chemical resistance and the like, and is widely used in various fields.

These vinyl chloride-based polymers are prepared in different forms depending on the use. For example, a vinyl chloride polymer for straight processing such as an extrusion process, a calendering process, and an injection process is generally produced by suspension polymerization, and a vinyl chloride polymer for paste processing such as dipping, spraying and coating is produced by emulsion polymerization.

The pasting is generally performed by spray drying a paste-working vinyl chloride polymer latex obtained by emulsion polymerization to form final resin particles, and the particles are dispersed in a solvent or a plasticizer to form a reverse roll-coating knife coatings, screen coatings, spray coatings, gravure and screen printing, rotocation casting, shell casting and dipping, to produce flooring, wallpaper, tarpaulin, Gloves, automotive underbody coatings, sealants and carpet tiles. Such vinyl chloride-based polymers for paste processing alone are difficult to apply because of low processability and are usually processed into plastisol form which is composed of various additives such as heat stabilizer together with a plasticizer. In order to improve workability, It is important to lower the viscosity of the styrene to maintain good flowability, and it is important that the viscosity change over time, that is, the viscosity retention rate is low.

Accordingly, the inventors of the present invention have developed a process for producing a novel vinyl chloride-based polymer capable of realizing a low viscosity property in mixing plastisols by controlling the water content and particle diameter of the vinyl chloride-based polymer, .

JP 2970659 B2 (Aug. 27, 1999)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art, and it is an object of the present invention to provide a vinyl chloride polymer having a remarkably low moisture content.

It is still another object of the present invention to provide a process for producing a vinyl chloride polymer capable of producing the vinyl chloride polymer.

Still another object of the present invention is to provide a plastisol which comprises the vinyl chloride-based polymer described above and can realize a low viscosity property and has a low viscosity-time rate.

In order to solve the above problems, the vinyl chloride polymer according to an embodiment of the present invention is characterized in that the vinyl chloride polymer has a water content of 10.5 ppm or less and an average particle diameter (D ₅₀ ) of 70 to 150 μm A vinyl chloride polymer is provided.

Also, the step of polymerizing the vinyl chloride monomer (step 1); And a step (step 2) of spray drying the vinyl chloride polymer so that the water content becomes 10.5 ppm or less based on the weight of the vinyl chloride polymer and the average particle diameter (D ₅₀ ) of the vinyl chloride polymer is 70 to 150 탆. A method for producing a polymer is provided.

The present invention also provides a plastisol containing the above vinyl chloride polymer and having a viscosity time-rate ratio of less than 1.5 for 24 hours.

The vinyl chloride polymer according to the present invention has a remarkably low water content and can be blended with a plasticizer as the particle diameter of the polymer is controlled to realize a low viscosity property in the production of a plastisol.

In addition, when the vinyl chloride polymer according to the present invention is prepared from a plastisol, there is an effect that the time-dependent viscosity ratio with time is greatly improved.

Accordingly, the vinyl chloride-based polymer according to the present invention and the method for producing the same can be easily applied to an industry that requires it, for example, a vinyl chloride resin industry for paste processing.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description of the invention, It should not be construed as limited.
1 and 2 are electron micrograph (SEM) photographs of Example 1 according to an embodiment of the present invention.
3 and 4 are electron micrograph (SEM) photographs of Comparative Example 2 according to an embodiment of the present invention.
5 and 6 are electron micrograph (SEM) photographs of Comparative Example 8 according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail in order to facilitate understanding of the present invention.

The terms and words used in the present specification and claims should not be construed in an ordinary or dictionary sense and the inventor can properly define the concept of the term to describe its invention in the best possible way It should be construed as meaning and concept consistent with the technical idea of the present invention.

As used herein, the term average particle size (D ₅₀ ) can be defined as the particle size corresponding to 50% of the particle number accumulation amount in the particle size distribution curve of the particles. The average particle diameter (D ₅₀ ) can be measured using, for example, a laser diffraction method. The laser diffraction method generally enables measurement of a particle diameter of several millimeters from a submicron region, resulting in high reproducibility and high degradability.

As used herein, the term "vinyl chloride polymer" refers to "vinyl chloride polymer solid" unless stated specifically to be a latex of vinyl chloride polymer, May mean "secondary particles" unless specifically described as primary particles.

As used herein, the term "primary particle" means a particle immediately after the vinyl chloride polymer is prepared, that is, a particle of a vinyl chloride polymer on a latex, and the term "secondary particle" In the course of the vinyl chloride-based polymer being converted into a solid through the drying process, the primary particles are formed by lumping together during drying, and the primary particles form the shell and core of the secondary particles.

As used herein, the term "resin" or "vinyl chloride polymer resin" refers to a state after the vinyl chloride polymer latex has undergone a drying process, and the vinyl chloride polymer may be present in a solid state.

The vinyl chloride polymer according to one embodiment of the present invention has a water content of 10.5 ppm or less and an average particle diameter (D ₅₀ ) of 70 to 150 탆 based on the weight of the vinyl chloride polymer.

Specifically, the vinyl chloride polymer may have a moisture content of 8.5 ppm or less, more preferably 5.0 to 8.0 ppm. In addition, the vinyl chloride polymer preferably has a particle diameter of 70 to 130 탆, more preferably 80 to 120 탆.

In the present invention, the vinyl chloride-based polymer having an average particle diameter may mean a vinyl chloride-based polymer solid formed after drying, and the vinyl chloride-based polymer solid matter may be composed of secondary particles of a vinyl chloride-based polymer.

In the present invention, when the water content of the vinyl chloride polymer exceeds 10.5 ppm, the produced vinyl chloride polymer contains a large amount of water. Therefore, when the moisture is evaporated, the pore of secondary polymer of the vinyl chloride polymer ) Is formed on the plastisol, and the vinyl chloride polymer formed with a large amount of voids is dispersed on the plasticizer, and when the plasticizer is blended, the plasticizer rapidly absorbs and the remaining plasticizer content, which is not absorbed in the vinyl chloride polymer, The viscosity of the plastisol is increased, and the rate of increase of the viscosity with time is also increased with time, so that the problem of poor processability may occur.

Small particles having a particle diameter of less than 70 占 퐉 of the vinyl chloride polymer tends to be inferior in rheological properties to particles having a large particle diameter. Therefore, when the average particle diameter of the vinyl chloride polymer of the present invention is less than 70 占 퐉, In the case of blending with styrenes, there may arise a problem that workability is lowered as the viscosity of the plastisol increases. When vinylidene chloride polymer particles having an average particle size exceeding 150 μm and a large particle diameter are formed, In the process of forming solid particles of the polymer, that is, secondary particles, a large amount of voids are formed due to the difference in drying rate between the shell and the core of the particles, and the quality of the protrusions Problems may arise, and the initial viscosity of the plastisol formulation is high, and the viscosity rate with time increases You may experience problems. Specifically, in the case of particles of a vinyl chloride polymer having an average particle size too large, that is, particles (secondary particles) of a vinyl chloride polymer solid, are formed, the outer part of the secondary particle is formed first due to the difference in drying speed, At this time, the primary particles in the central portion existing in the outer periphery are diffused toward the outer periphery, and the primary particles forming the outer periphery are combined with each other to form secondary particles. Accordingly, when the average particle diameter of the vinyl chloride polymer as the secondary particle is too large, the number of primary particles present in the center portion is relatively small, thereby forming a large number of voids, which may cause the above problems.

At this time, the moisture content may be measured by raising the temperature of the measurement chamber to 150 DEG C for 60 minutes using an ESCO TDS1200 II apparatus.

In the present specification, the ppm unit of the water content is a unit based on the weight of the vinyl chloride polymer, and the weight of the vinyl chloride polymer may mean the weight of the solid content of the vinyl chloride polymer.

The vinyl chloride-based polymer according to an embodiment of the present invention may be a vinyl chloride-based monomer alone or a mixture of a mixture of vinyl chloride-based monomer and vinyl chloride-based monomer copolymerizable with vinyl chloride-based monomer . That is, the vinyl chloride polymer according to an embodiment of the present invention may be a vinyl chloride homopolymer or a copolymer of a vinyl chloride monomer and a vinyl monomer capable of copolymerizing with the vinyl chloride monomer. If the vinyl chloride polymer is a copolymer as described above, it may contain at least 50% of vinyl chloride.

Examples of the vinyl monomer capable of copolymerizing with the vinyl chloride monomer include, but not limited to, olefin compounds such as ethylene, propylene and butene, vinyl esters such as vinyl acetate, vinyl propionate and vinyl stearate Unsaturated nitriles such as acrylonitrile, vinyl alkyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl octyl ether and vinyl lauryl ether, halogenated vinylidene halides such as vinylidene chloride, acrylic acid, methacrylic Unsaturated fatty acids such as maleic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride and itaconic anhydride, and anhydrides of these fatty acids, unsaturated fatty acid esters such as methyl acrylate, ethyl acrylate, monomethyl maleate, dimelkyl maleate, butyl benzyl maleate ), Diallyl phthalate, and the like, and the vinyl Monomer may be singly or in combination of two or more species

The method for producing a vinyl chloride monomer according to an embodiment of the present invention may be a method for producing the vinyl chloride polymer, specifically, a step of polymerizing a vinyl chloride monomer (step 1); And a step (step 2) of spray drying the vinyl chloride polymer so that the water content becomes 10.5 ppm or less based on the weight of the vinyl chloride polymer and the average particle diameter of the vinyl chloride polymer is 70 to 150 탆.

Each step will be described concretely.

Step 1

Step 1 of the process for producing a vinyl chloride polymer according to an embodiment of the present invention is a step of polymerizing a vinyl chloride monomer and initiating a polymerization reaction in a reactor to form a vinyl chloride monomer into a vinyl chloride polymer to be.

Specifically, the polymerization of Step 1 may be carried out by charging a vinyl chloride monomer into a polymerization reactor filled with the polymerization water, the first emulsifier and the polymerization initiator, and performing a polymerization reaction. In the present invention, a second emulsifier may be further added as needed, and the second emulsifier may be continuously added during the course of the polymerization reaction.

Here, the polymerization may preferably be carried out by an emulsion polymerization method.

The polymerization reactor filled with the polymerization water, the first emulsifier and the polymerization initiator may be a polymerization reactor containing a mixed solution containing polymerized water, a first emulsifier and a polymerization initiator, An emulsifier, a polymerization initiator, a dispersant, a molecular weight modifier, an electrolyte, a reaction inhibitor, and the like, but is not limited thereto.

The polymerization initiator may be used in an amount of 0.01 to 2.0 parts by weight based on 100 parts by weight of the vinyl chloride monomer. The polymerization initiator is not particularly limited, but may be one or more selected from the group consisting of peroxycarbonates, peroxyesters and azo compounds. Specifically, the polymerization initiator is at least one selected from the group consisting of lauryl peroxide (LPO), di-2-ethylhexyl peroxycarbonate (OPP), diisopropyl peroxy dicarbonate, t-butyl peroxy pivalate, Neodecanoate, and 2,2-azobisisobutyronitrile may be used alone or in combination of two or more.

Further, the polymerization initiator may be a water-soluble initiator. When the polymerization initiator is a water-soluble initiator, it is not particularly limited, but may be one or more selected from the group consisting of potassium persulfate, ammonium persulfate and hydrogen peroxide. In the present invention, a water-soluble initiator Specifically, potassium persulfate can be used.

The polymerized water may be used in an amount of 70 to 120 parts by weight based on 100 parts by weight of the vinyl chloride monomer, and the polymerized water may be deionized water.

The first emulsifier may be used in an amount of 0.01 part by weight to 0.4 part by weight based on 100 parts by weight of the vinyl chloride monomer. The second emulsifier may be continuously added during the reaction, And may be used in an amount of 1 part by weight to 15 parts by weight based on 100 parts by weight of the vinyl monomer.

In the present invention, the first emulsifier and the second emulsifier may be the same or different from each other. When the first emulsifier and the second emulsifier are the same substance, It may be for discrimination.

Specifically, the first emulsifier and the second emulsifier are each selected from the group consisting of sodium lauryl sulfate, sodium hydroxide, laurylbenzenesulfonic acid, alpha-olefinsulfonate, sodium dodecylbenzenesulfonate, sodium laurylethoxylate sulfate, Sodium lauryl sulfate, sodium octadecyl sulfate, sodium lauryl ether sulfate and a straight chain alkyl benzene sulfonate, and may preferably include sodium lauryl sulfate.

The reaction inhibitor is not particularly limited, and examples thereof include paraquinone, hydroquinone, butylated hydroxytoluene, monomethyl ether hydroquinone, quaternary butyl catechol, diphenylamine, triisopropanolamine , And triethanolamine. The dispersing agent is not particularly limited, and examples thereof include higher alcohols such as lauryl alcohol, myristic alcohol and stearyl alcohol, and alcohols such as lauric acid, myristic acid, palmitic acid, stearic acid And the like can be used.

The molecular weight regulator may be, for example, n-butyl mercaptan, n-octylmercaptan, n-dodecylmercaptan, t-dodecylmercaptan and the like. Examples of the electrolyte include potassium chloride, sodium chloride, May be at least one selected from the group consisting of potassium bicarbonate, sodium carbonate, potassium carbonate, potassium hydrogen sulfite, sodium hydrogen sulfite, sodium pyrophosphate, sodium pyrophosphate, tripotassium phosphate, trisodium phosphate, dipotassium hydrogenphosphate and disodium hydrogenphosphate The electrolyte is not particularly limited, but includes, for example, potassium chloride, sodium chloride, potassium bicarbonate, potassium carbonate, potassium hydrogen sulfite, sodium hydrogen sulfite, sodium pyrophosphate, sodium pyrophosphate, Potassium hydrogen phosphate, disodium hydrogen phosphate, disodium hydrogen phosphate, and the like.

The vinyl chloride monomer according to an embodiment of the present invention may be a vinyl chloride monomer alone or a mixture of a vinyl chloride monomer and a vinyl monomer copolymerizable with a vinyl chloride monomer. That is, the vinyl chloride polymer according to an embodiment of the present invention may be a vinyl chloride homopolymer or a copolymer of a vinyl chloride monomer and a vinyl monomer capable of copolymerizing with the vinyl chloride monomer. If the vinyl chloride polymer is a copolymer as described above, it may contain at least 50% of vinyl chloride.

The vinyl-based monomer capable of copolymerizing with the vinyl chloride-based monomer is as described above.

According to one embodiment of the present invention, the homogenization process can be performed on the polymerized water, the polymerization initiator, the first emulsifier, and the vinyl chloride monomer mixture, which are filled in the polymerization reactor, as needed before starting the polymerization reaction. The homogenization may be performed by homogenizing at a temperature of 30 DEG C or less, specifically, at a temperature of 5 DEG C to 25 DEG C using a homogenizer for 1 hour to 3 hours. At this time, the homogenizer is not particularly limited and conventional ones known in the art can be used. For example, a rotor-stator type homogenizer can be used.

The polymerization of Step 1 proceeded according to one embodiment of the present invention may terminate the polymerization reaction at a polymerization conversion rate of 85% or more.

The vinyl chloride-based polymer prepared in the step 1 may be present as a latex of a vinyl chloride-based polymer, and it may be dried in a step 2 described later to prepare a solid content of the vinyl chloride-based polymer.

Step 2

In the method for producing a vinyl chloride polymer according to an embodiment of the present invention, the step 2 is a step of spray drying, specifically, the step of spraying the vinyl chloride polymer latex prepared in step 1 with a water content of 10.5 ppm and the average particle diameter of the vinyl chloride polymer is 70 to 150 탆, and the water content of the final vinyl chloride polymer solid content to be produced is lowered and the average particle diameter is controlled.

Here, 'after polymerization' may mean after the polymerization reaction in Step 1 is terminated, and 'weight based on vinyl chloride polymer' may refer to the weight of solid content of vinyl chloride polymer.

According to an embodiment of the present invention, the step 2 can be roughly divided into two methods.

The first method is to adjust the temperature of the drying air (inlet temperature) at the dryer inlet, the temperature of the drying air at the outlet of the dryer (outlet temperature), the spraying rate of the vinyl chloride polymer latex (atomizer speed) And a method of controlling the feeding rate of the vinyl chloride-based polymer latex so that the water content becomes 10.5 ppm or less based on the weight of the vinyl chloride-based polymer and the average particle diameter of the vinyl chloride-based polymer is 70 to 150 탆, The method is a method in which the primary spray drying is performed and then the secondary drying is performed to dry the water to a water content of 10.5 ppm or less based on the weight of the vinyl chloride polymer and an average particle diameter of the vinyl chloride polymer of 70 to 150 탆 .

According to one embodiment of the present invention, the spray drying is performed in a dryer chamber composed of an atomizer rotating at high speed and a dry chamber including the atomizer, wherein the latex of the vinyl chloride polymer is sprayed from the atomizer, When scattered into the chamber, drying air is sprayed at the inlet of the dry chamber to quickly remove water, thereby obtaining a powder-type paste-type vinyl chloride polymer. Thereafter, drying is continued while the paste vinyl chloride polymer is moved to the outlet of the dry chamber, and when the outlet is exited, drying of the paste vinyl chloride polymer is completed.

In this case, the dryer used in the present invention is a rotary wheel atomizer, which is a FU 11 model of GEA Niro, and a dry air spraying method is a Co current spraying method which is introduced in the same direction as a latex to be introduced.

According to the first method of the drying method of step 2 according to the embodiment of the present invention, the drying temperature of the dryer inlet (inlet temperature) is 160 to 200 캜, the drying air temperature at the outlet of the dryer Temperature is higher than 75 ° C and lower than 95 ° C to dry the dispersion to a water content of 10.5 ppm or less based on the weight of the vinyl chloride polymer and an average particle diameter of the vinyl chloride polymer of 70 to 150 μm . Here, the drying time of the sprayed particles of step 2 may be performed for 0.5 to 3 minutes.

Specifically, the drying air temperature at the dryer inlet may be preferably 170 to 200 ° C, and the drying air temperature at the dryer outlet is preferably 78 to 92 ° C, more preferably 80 to 90 ° C To 10.5 ppm or less of the vinyl chloride polymer, and drying the vinyl chloride polymer so that the average particle diameter of the vinyl chloride polymer is 70 to 150 占 퐉.

When the temperature of the drying air at the dryer outlet is 75 캜 or lower, the drying temperature is low and moisture can not be effectively removed. Therefore, the water content in the vinyl chloride-based polymer is high and the vinyl chloride-based polymer is mixed with a plasticizer, The viscosity of the plastisol may be rapidly increased due to the reaction between the plasticizer and the water in the polymer during the production, and the viscosity increase rate with time may be increased. Furthermore, the temperature of the drying air at the outlet of the dryer Or 95 ° C or more, when the vinyl chloride type polymer latex is dried to form a solid content, the vinyl chloride type polymer is agglomerated or dried at a temperature higher than the glass transition temperature (Tg) of the vinyl chloride type polymer A problem that the vinyl chloride polymer resin is not normally formed due to deterioration of thermal stability Lt; / RTI >

In addition, in the first method, the spraying speed (atomizing speed) of the atomizer may be more than 5,000 rpm, less than 20,000 rpm, and preferably 10,000 to 15,000 rpm.

When the spraying rate is 5,000 rpm or less, the size of droplets of the vinyl chloride-based polymer latex to be sprayed is large, so that drying can not be performed properly and moisture can not be effectively removed. Therefore, the initial viscosity of the plastisol And the time-dependent viscosity is rapidly increased. When the spraying speed is higher than 20,000 rpm, the device has a limit in terms of heat generation and shortening of the life of the equipment. In addition, when the spraying speed of the vinyl chloride polymer latex The size of the droplet is too small, and the average particle diameter of the vinyl chloride polymer (solid content) to be produced may be small. As the average particle diameter becomes small, the viscosity property of the vinyl chloride polymer may decrease and the initial viscosity may become high.

In addition, in the first method, the feeding rate of the drying air at the dryer inlet may be 0.4 m / s to 1.5 m / s. When the feeding rate is less than 0.4 m / s, the feeding of the drying air is too slow As a result, there is a problem that the drying time is prolonged. As a result, the temperature of the drying air at the dryer inlet is adjusted to a high temperature in order to proceed smooth drying. The thermal stability may deteriorate and deterioration may occur. In addition, when the air inlet speed of the inlet is excessively fast, exceeding 1.5 m / s, the initial drying speed is too fast when the dry air introduced from the air dispenser meets the droplet, ) Are formed first, and then the polymer particles present in the shell are diffused toward the shell through the liquid phase diffusion and the gas phase diffusion process, and at the same time, they are dried to form secondary particles. Thus, secondary particles of the vinyl chloride- There may arise a problem that pores in the solid particles are excessively formed.

In the first method, the feed rate of the vinyl chloride-based polymer latex may be from 100 g / min to 400 g / min, preferably from 150 g / min to 300 g / min. When the range is satisfied, The temperature of the drying air of the drying apparatus can be maintained at more than 75 DEG C and less than 95 DEG C as described above.

According to the second method of the drying method of step 2 according to another embodiment of the present invention, the step 2 is first spray-dried to produce a vinyl chloride polymer in an amount exceeding 10.5 ppm based on the weight of the vinyl chloride-based polymer Step (step 2-1); And a step (step 2-2) of secondary drying such that the moisture content is 10.5 ppm or less based on the weight of the vinyl chloride polymer and the average particle diameter of the vinyl chloride polymer is 70 to 150 占 퐉.

Here, the primary drying is not particularly limited as long as it is a spray drying method. Since the secondary drying is further performed, it is not necessary to dry the primary drying to a moisture content of 10.5 ppm or less. In the second method, the drying method is not particularly limited as far as the moisture content of the vinyl chloride-based polymer to be finally produced is 10.5 ppm or less based on the weight of the vinyl chloride-based polymer. For example, The secondary drying can be carried out.

The second drying method is advantageous in that the drying load of the dryer is relatively small in the first drying since the second drying is performed so that moisture is not removed to a moisture content of 10.5 ppm or less by one drying.

In the case of producing a vinyl chloride polymer according to the production method of a vinyl chloride polymer according to an embodiment of the present invention, it is possible to produce a vinyl chloride polymer having a water content of 10.5 ppm or less and an average particle diameter of 70 to 150 탆 have.

Further, according to one embodiment of the present invention, the present invention provides a plastisol comprising the vinyl chloride-based polymer.

The plastisol according to one embodiment of the present invention is used in an amount of 40 to 180 parts by weight, preferably 80 to 160 parts by weight, more preferably 100 to 100 parts by weight (based on 100 parts by weight of solid content) To 140 parts by weight of a plasticizer, and may further contain additives such as a dispersion diluent, a heat stabilizer, a viscosity adjusting agent and a foaming agent, if necessary. As the plasticizer and the additive, those conventionally known in the art can be used.

The term "plastisol" used in the present invention refers to a mixture of a resin and a plasticizer so as to be processed into a molding, a mold, or a continuous film by heating. For example, a mixture of a vinyl chloride polymer and a plasticizer And may represent a paste phase.

The term "plasticizer " used in the present invention may refer to an organic additive material which serves to improve moldability at high temperature by adding thermoplastic resin to the thermoplastic resin to increase the thermoplasticity.

The plastisol according to one embodiment of the present invention can realize a low viscosity property even when a plastisol is produced by dispersing the plastisol in a plasticizer as it contains a vinyl chloride polymer having a remarkably small moisture content and an average particle size within a specific range, It can have a low viscosity and a low elapsed time property. In particular, the viscosity retention rate over 24 hours is less than 1.5 and can be very low.

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 for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example

Example 1

170 kg of polymerization water, 120 g of sodium laurylsulfate, 120 g of sodium hydroxide and 50 g of potassium persulfate (KPS) were charged into a 500 L high-pressure reactor, and the reactor was vacuumed while stirring. 180 kg of a vinyl chloride monomer was charged into a reactor in a vacuum state, and the temperature of the reactor was raised to 58 ° C to conduct polymerization. When the polymerization was initiated, 20 kg of sodium lauryl sulfate was continuously fed into the reactor for 6 hours. Thereafter, the reaction was terminated at a polymerization conversion of 85% or more, and the unreacted vinyl chloride monomer was recovered and removed to prepare a vinyl chloride polymer latex. The vinyl chloride-based polymer latex is sprayed into the dryer chamber using an atomizer rotating at 10,800 rpm. At this time, the dry air temperature at the inlet of the dryer was adjusted to 195 ° C., the feed rate of the dry air at the inlet was adjusted to 0.9 m / s, and then the vinyl chloride type polymer latex was fed at 230 g / min to remove water Before reaching the chamber wall, a vinyl chloride type polymer in powder form is obtained. Thereafter, the temperature of the dry air at the bottom of the chamber, that is, the outlet of the dryer, is adjusted to 80 캜 to obtain a final dried vinyl chloride polymer.

Example 2

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that the drying conditions in Table 1 were changed to those in Example 1.

Comparative Example 1

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that the drying conditions in Table 1 were changed to those in Example 1.

Comparative Example 2

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that the drying conditions in Table 1 were changed to those in Example 1.

Comparative Example 3

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that the drying conditions in Table 1 were changed to those in Example 1.

Comparative Example 4

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that the drying conditions in Table 1 were changed to those in Example 1.

Comparative Example 5

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that the drying conditions in Table 1 were changed to those in Example 1.

Comparative Example 6

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that the drying conditions in Table 1 were changed to those in Example 1.

Comparative Example 7

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that the drying conditions in Table 1 were changed to those in Example 1.

Comparative Example 8

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that the drying conditions in Table 1 were changed to those in Example 1.

Experimental Example 1: Measurement of Physical Properties of Vinyl Chloride Polymer

1) Electron Microscope (SEM) photography

The vinyl chloride polymer prepared in Example 1, Comparative Example 2, and Comparative Example 8 was photographed by an electron microscope (SEM).

1: x 1,100, scale bar: 10.0 m

2: x 5,000, scale bar: 1.0 m

3: x 550, scale bar: 10.0 m

4: x 5,000, scale bar: 1.0 m

5: x 200, scale bar: 100.0 m

6: x 900, scale bar: 10.0 m

2) Moisture content measurement

The water content of each of the vinyl chloride polymers prepared in the above Examples and Comparative Examples was measured using ESCO TDS1200 II. The results are shown in Table 1 below.

Exhaust the specimen until it reaches 10 ^-3 Pa in the load-lock chamber, and transfer it to the measuring chamber. The initial temperature of the measurement chamber is 40 ° C. After exhausting for 60 minutes in the measuring chamber, the temperature of the sample is raised to 150 ° C at a constant temperature rise rate (0.3 ° C / s). After reaching 150 캜, the water content in the vinyl chloride polymer was measured while maintaining the temperature for 60 minutes.

3) Measurement of average particle diameter (D ₅₀ )

The average particle size (D ₅₀ ) of the solid content of the vinyl chloride polymer was measured using a particle size analyzer (Sympatec HELOS) without grinding the vinyl chloride polymer solid obtained after drying the respective vinyl chloride polymer, and the results are shown in Table 1 .

Experimental Example 2: Measurement of Viscosity Property of Plastisol

Viscosity characteristics such as viscosity, viscosity elapsed time and the like of the plastisol containing each vinyl chloride polymer prepared in the above Examples and Comparative Examples were measured and the results are shown in Table 1 below.

First, 100 g of each vinyl chloride polymer and 120 g of dioctyl phthalate (DOP) were stirred at 800 rpm for 10 minutes using a Werke mixer (EUROSTAR IKA) to prepare each plastisol. Was evaluated by the following method.

The viscosity of each of the above plastisols was measured 1 hour after mixing and after 24 hours of mixing, the viscosity was measured using a Brookfield viscometer, and the viscosity retention rate was calculated according to the following formula (1).

[Equation 1]

Here, the lower the viscosity elapsed time rate is, the smaller the change in viscosity is, and therefore, the viscosity property may be excellent.

division Drying conditions Moisture content
(wt ppm) Average particle diameter (D ₅₀ , 占 퐉) Resin
Formation Viscosity characteristic Dry inlet temperature Dry outlet temperature Atomizer Speed
(rpm) Dry inlet air feed rate
(m / s) Latex feed rate
(g / min) After 1 hour of mixing
(cP) After 24 hours of mixing
(cP) Viscosity aging rate
(1day) Example 1 195 80 10800 0.9 230 6.81 ± 1.41 117 ○ 11500 13000 1.1 Example 2 195 90 10800 1.4 250 6.48 0.97 118 ○ 11200 12500 1.1 Comparative Example 1 195 40 10800 0.9 280 - - X - - - Comparative Example 2 195 50 10800 0.9 270 13.84 1.52 115 ○ 30200 72800 2.4 Comparative Example 3 195 60 10800 0.9 260 12.77 ± 1.15 114 ○ 24300 46200 1.9 Comparative Example 4 195 70 10800 0.9 250 12.46 + - 0.57 115 ○ 18200 29300 1.6 Comparative Example 5 195 75 10800 0.9 240 11.15 ± 0.21 115 ○ 16000 24500 1.5 Comparative Example 6 195 95 10800 0.9 225 - 115 X - - - Comparative Example 7 195 80 20000 0.9 230 5.87 ± 1.43 35 ○ More than 100,000 10 million
More than - Comparative Example 8 195 80 5000 0.9 230 18.94 + 1.31 180 ○ 16000 56000 3.5

As shown in Table 1, it was confirmed that the vinyl chloride polymer of the examples according to the present invention had a significantly lower moisture content than that of the vinyl chloride polymer of the comparative example, and that the particle diameter was included in the range of 70 to 150 μm have. Also, it can be seen that the plastisol containing the vinyl chloride-based polymer prepared according to the embodiment can realize the initial low viscosity property, and the viscosity-time ratio with time is also greatly improved.

On the other hand, in the case of the vinyl chloride-based polymer of the comparative example, the water content was higher than that of the examples, the average particle diameter was smaller, and the viscosity was relatively high and the viscosity-time rate was also high in the case of the plastisol.

In particular, when Examples 1 and 2 and Comparative Examples 1 to 6 were compared, when the drying conditions according to one embodiment of the present invention were all satisfied, the moisture content was significantly lower than that of Examples 1 and 2, The viscosity properties of the sol are also excellent. In particular, in Comparative Example 1, in which the temperature of the drying air at the outlet of the dryer is extremely low in the drying condition, the drying temperature is too low, so that the vinyl chloride type polymer latex can not be dried sufficiently and normal resin can not be formed. In Comparative Example 6 in which the temperature of the drying air of Comparative Example 6 is extremely high, the air temperature is higher than the glass transition temperature of the vinyl chloride polymer, and therefore the thermal stability of the vinyl chloride polymer is deteriorated and deteriorated, .

In addition, when Examples 1 and 2 and Comparative Examples 7 and 8 were compared, it was found that by controlling the spraying rate to a specific value range in the drying condition, the average particle size was adjusted to a desired level while the water content was low, Viscosity characteristics and improved the viscosity time-rate change with time, whereas in Comparative Example 7, since the average particle diameter of the polymer was extremely small due to the spray rate being too high, the low viscosity property In Comparative Example 8, since the drying rate was too low due to the low spraying rate, the viscosity of the polymer could not be improved due to the increase in the moisture content of the polymer, and the viscosity change rate with time As shown in Fig.

1 and 2, it can be confirmed that, in the case of Example 1, voids are hardly formed in the form of secondary particles formed after drying the vinyl chloride polymer , It can be confirmed that primary particles of the vinyl chloride-based polymer are aggregated well during drying to maintain globular spherical particles as a whole. Thus, it can be seen that the vinyl chloride-based polymer of Example 1 has low initial viscosity at the time of blending plastisols, and can also improve viscosity change rate with time.

On the other hand, in the case of Comparative Example 2 shown in FIGS. 3 and 4, in the form of secondary particles formed after drying of the vinyl chloride polymer, the pores were formed to some extent as compared with the examples, However, when the particle size is enlarged at a higher magnification, it can be confirmed that the primary particles do not aggregate well during drying, and therefore spherical particles can not be retained and have irregular particles. As a result, it can be seen that the vinyl chloride polymer of Comparative Example 2 can not achieve the initial low viscosity property when blending the plastisol, and the viscosity change rate with time can also be deteriorated.

In the case of Comparative Example 8 shown in Fig. 5 and Fig. 6, it can be seen that secondary particles formed after drying of the vinyl chloride polymer were broken without being spherical, and when expanded at a high magnification, It can be confirmed that a large number of pores are formed in the form of. As a result, it can be seen that the initial low viscosity property can not be realized when the plastisol is blended, and the viscosity change rate with time can also be remarkably decreased.

As described above, in the production process of the vinyl chloride polymer, the feeding rate of the drying air temperature at the dryer inlet and outlet, the spraying rate, the feed rate of the latex, and the drying air temperature at the dryer inlet are determined according to one embodiment of the present invention When the range is satisfied, low viscosity properties can be realized in the blending of plastisols, and the time-dependent viscosity ratio with time can be greatly improved, and a vinyl chloride polymer having excellent processability can be produced.

Claims (13)

Based on the weight of the vinyl chloride polymer, a water content of 10.5 ppm or less,
A vinyl chloride-based polymer having an average particle diameter (D ₅₀ ) of 70 to 150 μm.
The method according to claim 1,
Wherein the vinyl chloride polymer has a water content of not more than 8.5 ppm based on the weight of the vinyl chloride polymer.
The method according to claim 1,
Wherein the average particle diameter (D ₅₀ ) of the vinyl chloride polymer is 80 to 120 탆.
Polymerizing the vinyl chloride monomer (step 1); And
(Step 2) in which the water content is 10.5 ppm or less based on the weight of the vinyl chloride polymer and the average particle diameter (D ₅₀ ) of the vinyl chloride polymer is 70 to 150 탆. ≪ / RTI >
5. The method of claim 4,
Wherein the temperature of the drying air at the inlet of the dryer is in the range of 160 to 200 DEG C in step 2 above.
5. The method of claim 4,
Wherein the drying air temperature at the dryer outlet is higher than 75 캜 and lower than 95 캜 in said step 2.
5. The method of claim 4,
Wherein in step 2, the drying air temperature at the dryer outlet is 80 to 90 ° C.
5. The method of claim 4,
Wherein the spraying rate of the spray drying is greater than 5000 rpm and less than 20,000 rpm.
5. The method of claim 4,
Wherein the supply rate of the vinyl chloride latex is 100 to 400 g / min in the step 2.
Polymerizing the vinyl chloride monomer (step a);
A first spray drying step (step b); And
Based on the weight of the vinyl chloride polymer, a step of secondary drying (step c) such that the water content becomes 10.5 ppm or less and the vinyl chloride-based polymer has an average particle diameter (D ₅₀ ) of 70 to 150 탆. Gt;
11. The method of claim 10,
Wherein the step (c) is carried out in a fluidized bed dryer.
5. The method of claim 4,
Wherein the polymerization is an emulsion polymerization.
A vinyl chloride polymer composition comprising the vinyl chloride polymer according to claim 1,
Wherein the viscosity aging ratio during 24 hours is less than 1.5.

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