KR102304735B1 - Polyvinyl chloride and preparation method for the same - Google Patents

Abstract

The present invention relates to a vinyl chloride-based polymer and a method for producing the same, and by controlling the tip speed of a stirrer blade at a specific conversion rate, excellent fogging properties and foaming properties of plastisol without adding additional additives, and low viscosity It relates to a vinyl chloride-based polymer capable of implementing properties and a method for manufacturing the same.

Description

Vinyl chloride-based polymer and manufacturing method thereof

The present invention relates to a method for producing a vinyl chloride-based polymer, and to a method for producing a vinyl chloride-based polymer having low viscosity characteristics.

A vinyl chloride-based polymer is a polymer containing 50% or more of vinyl chloride, and has a wide range of applications because it is inexpensive, can easily control hardness, and can be applied to most processing equipment. In addition, it can provide a molded article having excellent physical and chemical properties, such as mechanical strength, weather resistance, chemical resistance, and the like, and thus is widely used in various fields.

These vinyl chloride-based resins are manufactured by mixing various additives such as a plasticizer, a colorant, and a heat stabilizer, and then molding them through an extrusion process, a calendar process, an injection process, a paste process, and the like. In particular, in the case of paste processing that is mixed with a plasticizer, it is molded into products for various uses in various fields such as building materials, toys, artificial leather, shoes, and gloves, depending on the processing method.

The paste processing is generally performed by spray drying the vinyl chloride-based polymer for paste processing obtained by emulsion polymerization to form final resin particles, and the particles are plastics composed of various additives such as solvents, plasticizers, and heat stabilizers. It is prepared in the form of a sol for coating (reverse roll-coating, knife coating, screen coating, spray coating), gravure and screen printing, rotation casting, shell casting and dipping (shell casting and dipping) It is applied to products such as flooring, wallpaper, tarpaulin, raincoats, gloves, automobile underbody coatings, sealants, and carpet tiles through the same process.

In this case, the viscosity in the plastisol state has a high contribution to the processing characteristics. The lower the viscosity based on the same amount of plasticizer used, the more advantageous it is for processing, so the implementation of low viscosity is a very important part.

In general, as a method of lowering the viscosity, it can be divided into a method that can be treated under polymerization conditions and processing conditions. However, the conventional polymer plastisol prepared by using a low-viscosity emulsifier or by increasing the particle diameter of the polymer is difficult to apply because the foaming properties are inferior. However, in this case, there is a problem in that the foaming color is deteriorated or the cost is increased.

In addition, as suggested in Korean Patent Application Laid-Open No. 2009-0067946, there is a method of injecting a viscosity modifier capable of controlling the viscosity under processing conditions, but the commonly used viscosity modifier not only deteriorates foam properties during processing, but also volatile It causes the generation of organic compounds, which adversely affects the properties of fogging and is harmful to the human body.

On the other hand, vinyl chloride-based polymers are manufactured and used through bulk polymerization, suspension polymerization, or emulsion polymerization according to the desired purpose. There is a problem in that aggregates and deposits (scale) are generated in the polymerization apparatus. These aggregates or deposits not only reduce productivity but also adversely affect the quality of latex. For this reason, various methods have been proposed to reduce the occurrence of aggregates and scale, for example, there is a method of increasing the ratio of the polymerization water to the monomer.

However, although the above method reduces the generation of some aggregates and scales, there is a disadvantage in that productivity is lowered because the proportion of the polymer generated in the reaction solution decreases as the proportion of polymerization water increases.

In this way, while maintaining an excellent level of fogging properties and foaming properties, a vinyl chloride-based polymer having a low viscosity characteristic as a compounding property is produced, and at the same time, scale is generated in the reactor and stirring device even if heterogeneous polymerization such as emulsion polymerization is performed. There is a need for technological development for a method for producing a vinyl chloride-based polymer that is suppressed.

KR2009-0067946 (published on June 25, 2009)

The present invention has been devised to solve the problems of the prior art, and an object of the present invention is to provide a vinyl chloride-based polymer in which scale generation is suppressed during polymerization while implementing low-viscosity characteristics.

In order to solve the above problems, the present invention adjusts the tip speed of the stirrer blade to 1 to 1.5 m/s at the time when the conversion rate is 0 to 40% after the start of the emulsion polymerization reaction, and the tip speed is adjusted There is provided a method for producing a vinyl chloride-based polymer that maintains the tip speed until after the reaction is completed.

In addition, the average particle diameter (D ₅₀ ) is 0.6 to 0.8 μm, and the number of particles (Nc) is 7.0x10 ¹⁴ /L to 1.2x10 ¹⁵ /L The vinyl chloride-based polymer prepared by the above manufacturing method is provided.

In addition, there is provided a plastisol having a viscosity of 5 to 20 Pa·s including the vinyl chloride-based polymer.

In the method for producing a vinyl chloride-based polymer according to the present invention, the tip speed of the stirrer blade is adjusted to 1 to 1.5 m/s at the time when the conversion rate is 0 to 40%, and the tip speed is maintained until the end of the reaction. By proceeding the polymerization reaction, the amount of scale generated inside the reactor can be suppressed, and a polymer can be manufactured that realizes a low viscosity characteristic as a compounding property and maintains an excellent level of fogging properties.

In addition, the method for producing a vinyl chloride-based polymer of the present invention uses an emulsifier having a high plastisol viscosity to have excellent foaming properties. It is possible to prepare a polymer capable of having

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

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

The present invention provides a method for producing a vinyl chloride-based main body capable of producing a vinyl chloride-based polymer having blending physical properties of low viscosity characteristics.

In the method for producing the vinyl chloride-based polymer according to an embodiment of the present invention, the tip speed of the stirrer blade is adjusted to 1 to 1.5 m/s at the time when the conversion rate is 0 to 40% after the start of the emulsion polymerization reaction. and maintaining the tip speed until the reaction is completed after adjusting the tip speed.

The emulsion polymerization reaction is a step for preparing a vinyl chloride-based polymer latex by polymerizing a vinyl chloride-based monomer, and may be performed by polymerizing the vinyl chloride-based monomer in the presence of a polymerization initiator and an emulsifier.

Specifically, the polymerization may be carried out by polymerization of a vinyl chloride monomer in the presence of polymerization water, a water-soluble polymerization initiator and an emulsifier, and in this case, the emulsifier may be additionally added continuously during polymerization.

In addition, the polymerization reaction in the presence of polymerization water, a water-soluble polymerization initiator and an emulsifier may be carried out by adding a vinyl chloride monomer to a reactor including polymerization water, a water-soluble polymerization initiator and an emulsifier to perform a polymerization reaction.

For example, the polymerization is carried out in an amount of 70 parts by weight to 120 parts by weight of polymerization water, 0.01 parts by weight to 2.0 parts by weight of a water-soluble polymerization initiator, preferably 0.06 parts by weight to 0.1 parts by weight, and 0.01 parts by weight of an emulsifier based on 100 parts by weight of the vinyl chloride monomer. to 0.4 parts by weight, preferably 0.02 parts by weight to 0.1 parts by weight, in a vacuum reactor containing 100 parts by weight of a vinyl chloride-based monomer, and polymerization may be initiated at a temperature range of 30°C to 70°C.

In addition, if necessary, 0.1 to 6 parts by weight, preferably 0.6 to 1.4 parts by weight, of the emulsifier based on 100 parts by weight of the vinyl chloride-based monomer may be added continuously during the polymerization reaction.

In the present invention, both polymerization and polymerization may have the same meaning as emulsion polymerization.

According to an embodiment of the present invention, in the method for preparing the vinyl chloride-based polymer, the polymerization conversion rate after the start of the emulsion polymerization reaction is 0 to 40%, preferably 5 to 20%, and even more preferably 5 to 10%. At this point, the tip speed of the stirrer blade may be adjusted to 1 to 1.5 m/s, preferably 1.05 to 1.47 m/s, and more preferably 1.2 to 1.47 m/s to proceed with the polymerization reaction, the tip speed may be kept the same until the reaction is completed.

Here, "when the reaction is terminated" may refer to a point in time when the polymerization reaction is completed through stirring of the reactants, and all of the resulting polymer latex is recovered from the reactor, ie, degassed.

In addition, in the present invention, a step of removing heat through reflux may be performed while the polymerization reaction through stirring proceeds in the present invention, and the polymerization period and a separate reflux period are not distinguished, and may be carried out simultaneously.

That is, in the method for producing a polymer according to an embodiment of the present invention, the tip speed of the aforementioned stirrer blade is maintained the same from the specific conversion rate described above to the point of recovery of the polymerized latex from the reactor after the polymerization reaction is started. can

On the other hand, when the polymerization conversion rate exceeds 40%, when the tip speed is adjusted to the above numerical range, the growth of the particle size of the polymer is mostly finished and it is difficult to control the viscosity of the prepared polymer because it is after the stabilized polymer is formed. There may be a problem of not having the characteristics.

In addition, when the tip speed of the agitator blade is adjusted to less than 1.0 m/s, the viscosity gradually rises, making it difficult to realize low-viscosity characteristics, and due to the low stirring force, it is possible to uniformly remove heat through local particle growth and exothermic reaction. none. On the other hand When the tip speed of the stirrer blade exceeds 1.5 m/s, the shear force received by the initially generated polymer particles is excessively increased, and due to inter-particle aggregation, the produced polymer latex causes agglomeration, and a normal polymer latex can be obtained. There may be a problem that there is no problem, and furthermore, a problem in which the amount of scale generated inside the reactor is significantly increased may occur.

The term "polymerization conversion" used in the present invention refers to the degree of conversion of the vinyl chloride-based monomer to a polymer, and may be measured using a butane tracer equipped with gas chromatography. Specifically, a polymerization conversion curve according to the ratio of vinyl chloride monomer and butane according to time according to each condition under certain polymerization conditions was prepared for each polymerization condition, and based on this, polymerization conversion rate was obtained according to polymerization conditions. In addition, the polymerization conversion rate may include up to an error range according to the measurement.

The vinyl chloride monomer may be a mixture of a vinyl chloride monomer or a vinyl chloride monomer and a vinyl monomer having copolymerizability with the vinyl chloride monomer, wherein the vinyl chloride monomer is a mixture of a vinyl chloride monomer and a vinyl monomer In this case, it may be used by appropriately adjusting the amount of vinyl chloride in the vinyl chloride-based polymer prepared through this method so that 50% by weight or more is included.

The vinyl-based monomer is not particularly limited, for example, olefin (olefin) compounds such as ethylene, propylene, butyne; vinyl esters such as vinyl acetate, vinyl propionate, and vinyl stearate; unsaturated nitriles such as acrylonitrile; vinylalkyl ethers such as vinylmethyl ether, vinylethyl ether, vinyloctyl ether, and vinyllauryl ether; vinylidene halides such as vinylidene chloride; unsaturated fatty acids such as acrylic acid, methacrylic 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, dimethyl maleate, and butylbenzyl maleate; It may be a cross-linkable monomer such as diallyl phthalate, and the vinyl-based monomer may be used alone or in combination of two or more.

The emulsifier is not particularly limited as long as it is commonly used in the art, and specifically, alkane sulfonate, alpha-olefin sulfonate, straight chain alkylbenzene sulfonate, alkane sulfate, alkane ethoxylated sulfate, alkane ether sulfate, alkyl It may be at least one selected from among benzene sulfonic acids, for example, alkane sulfonate, alpha-olefin sulfonate, straight chain alkylbenzene sulfonate, sodium dodecyl benzene sulfonate, alkane sulfate, alkane sodium lauryl ethoxylated sulfate, It may be at least one selected from sodium octadecyl sulfate, sodium lauryl ether sulfate, sodium lauryl sulfate, and lauryl benzene sulfonic acid.

Preferably, the emulsifier in the present invention is an alkane sulfate emulsifier alone or a sulfonate-based emulsifier of at least one of the alkane sulfonate, alpha-olefin sulfonate, and straight-chain alkylbenzene sulfonate, and the alkane sulfate and alkane ethoxylay A mixture of one or more sulfate-based emulsifiers among tide sulfate and alkane ether sulfate may be used. In this case, the sulfate-based emulsifier may preferably use alkane sulfate.

The above emulsifiers, among others, sulfate-based emulsifiers including alkane sulfates are emulsifiers advantageous for foaming properties, and are mainly used for the purpose of improving the foaming properties of plastisols containing vinyl chloride-based polymers. When the emulsifier is used, the foaming properties can be improved, but it was difficult to apply a product requiring low viscosity characteristics due to high plastisol viscosity. In order to solve this problem, in the present invention, as stated above, by controlling the tip speed when preparing the vinyl chloride-based polymer, it is possible to prepare a polymer having a low viscosity characteristic as a compounding property while maintaining excellent foaming properties.

The polymerization initiator is not particularly limited, and any one or more of a water-soluble initiator and an oil-soluble initiator may be used. For example, it may be one or more selected from the group consisting of peroxy carbonates, peroxy esters, and azo compounds. Specifically, as the polymerization initiator, diisopropyl peroxydicarbonate, t-butyl peroxypivalate, t-butylperoxyneodecanoate, 2,2-azobisisobutyronitrile, etc. are used alone, Two or more types may be mixed and used.

In addition, when a water-soluble initiator is used as the polymerization initiator, it may be preferably at least one selected from the group consisting of potassium persulfate, ammonium persulfate and hydrogen peroxide.

In addition, as the polymerization solvent, various kinds of polymerization water such as distilled water or deionized water may be used as the polymerization water, 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 emulsion polymerization takes place.

In addition, the emulsion polymerization may be carried out by adding additives such as a dispersant and a reaction inhibitor as needed in addition to the polymerization initiator, the emulsifier and the polymerization water.

The dispersing agent is not particularly limited, and for example, higher alcohols such as lauryl alcohol, myristic alcohol, and stearyl alcohol or higher fatty acids such as lauryl acid, myristic acid, palamitic acid, and stearic acid may be used.

The reaction inhibitor is not particularly limited, for example, paraquinone, hydroquinone, butylated hydroxy toluene, monomethyl ether hydroquinone, quaternary butyl catechol, diphenyl amine, triisopropanol amine, triethanol amines and the like can be used.

On the other hand, in the manufacturing method according to an embodiment of the present invention, the step of recovering and drying the vinyl chloride-based polymer latex prepared after the emulsion polymerization reaction may be performed, and prior to the drying step, a conventional method It may further include a step of washing according to the, and the drying is not limited as long as it is a conventionally applied drying method, but specifically, a spray drying method may be applied.

In addition, the vinyl chloride-based polymer latex produced by polymerization may be dried as it is without going through the washing step to obtain a vinyl chloride-based polymer, and the total amount of the active ingredient used during polymerization is the final material produced after the polymerization reaction. It may be included in the vinyl chloride-based polymer.

According to an embodiment of the present invention, the method for producing the vinyl chloride-based polymer is advantageous in low viscosity that can deteriorate the foaming properties of the plastisol in order to realize the low viscosity characteristics of the polymer, plastisol, and molded article to be manufactured. Because the polymer is not prepared by applying an emulsifier or by seed polymerization, and a post additive for lowering the viscosity or a viscosity lowering agent is not separately added during processing, it has excellent fogging and foaming properties when blended with plastisol, but also has low viscosity properties It is possible to prepare a vinyl chloride-based polymer that can implement.

Here, the fogging properties are properties related to the amount of volatile organic compounds generated from the vinyl chloride-based polymer, and the lower the amount of the volatile organic compounds generated, the better the fogging properties.

On the other hand, according to an embodiment of the present invention, the present invention is a vinyl chloride-based polymer having an _{average particle diameter (D 50} ) of 0.1 to 1.0 μm and a particle number (Nc) of 3.0x10 ¹⁴ /L to ^{1.5x10 15 /L} may be provided. Here, the vinyl chloride-based polymer may be prepared according to the above manufacturing method.

Specifically, the vinyl chloride-based polymer of the present invention may have an average particle diameter (D ₅₀ ) of 0.3 to 0.9 μm, more preferably 0.6 to 0.8 μm, and the number of particles (Nc) of 5.0x10 ¹⁴ /L to 1.3x10 ¹⁵ /L, more preferably 7.0x10 ¹⁴ /L to 1.2x10 ¹⁵ /L.

In the present specification, the average particle diameter (D ₅₀ ) may be defined as a particle diameter corresponding to 50% of the cumulative number in the particle size distribution curve of the particles. The average particle diameter (D ₅₀ ) may be measured using, for example, a laser diffraction method. The laser diffraction method is generally capable of measuring a particle diameter of several mm from a submicron region, and can obtain high reproducibility and high resolution results.

In addition, the present invention provides a plastisol containing the vinyl chloride-based polymer and a molded article manufactured using the plastisol. The plastisol and the molded article may include a vinyl chloride-based polymer prepared according to the above manufacturing method.

Specifically, the plastisol may include 100 parts by weight of a vinyl chloride-based polymer and 40 to 120 parts by weight of a plasticizer, preferably 60 to 100 parts by weight, and, if necessary, a dispersion diluent, a heat stabilizer, Additives such as viscosity reducing agents and foaming agents may be further included.

The plastisol containing the vinyl chloride-based polymer according to the present invention has excellent fogging properties and foaming properties. The foaming properties of the sol may be 5.0 to 6.0 times by measuring the foaming ratio, and the foaming properties and foaming ratio can be calculated by Equations 1 and 2 below, respectively.

[Equation 1]

Amount of volatile organic compounds generated (mg) = mass of aluminum foil after fogging test - mass of aluminum foil before fogging test

[Equation 2]

Foaming properties = Thickness after conducting at 220℃, 120 seconds / Thickness after performing pre-gelling at 150℃, 60 seconds

In the present invention, the term "plastisol" refers to a mixture of a resin and a plasticizer so that it can be molded, molded, or processed into a continuous film by heating, for example, a paste in which a vinyl chloride-based polymer and a plasticizer are mixed. may indicate

In the present invention, the term "plasticizer" may refer to an organic additive material that serves to improve the moldability of the resin at a high temperature by adding it to the thermoplastic resin to increase the thermoplasticity.

The plasticizer and the additive are not particularly limited, and those conventional in the art may be used, and although not particularly limited, the plasticizer may specifically include dioctyl phthalate (DPO).

In addition, the plastisol according to the present invention may have a low viscosity characteristic with a viscosity of 5 to 20 Pa·s, preferably 6 to 12 Pa·s, and the viscosity characteristic is the vinyl chloride contained in the plastisol. It may be expressed from a type polymer.

In addition, the molded article may be a paste molded article manufactured by paste processing using plastisol. The molded article is manufactured by using the plastisol containing the vinyl chloride-based polymer according to an embodiment of the present invention, so that the generation of volatile organic compounds is reduced compared to the conventional molded article manufactured using a conventional vinyl chloride-based polymer. can

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

Example 1

100 parts by weight of polymerization water, 0.06 parts by weight of an initiator (Potassium persulfate), and 0.02 parts by weight of an emulsifier (Alkane sulfate) were added to a reactor with an internal volume of 0.5 m ^{3 to which a stirrer was attached, and a vacuum was applied to the reactor while stirring.} After 100 parts by weight of vinyl chloride monomer was added to the reactor in a vacuum state, the temperature of the reactor was raised to 55° C. to initiate polymerization. At this time, the tip speed of the stirrer blade inside the reactor is 0.84 m/s. Thereafter, the reaction was carried out by adjusting the tip speed of the stirrer blade inside the reactor to 1.05 m/s at the time when the polymerization conversion rate was 5%. After 2 h of polymerization, 0.8 parts by weight of an emulsifier was continuously added. When the internal pressure of the reactor reached 3.5 K/G, the reaction was terminated, the prepared polymer latex was recovered, and then spray-dried (inlet: 195° C., outlet: 65° C.) to prepare a vinyl chloride-based polymer.

Example 2

In Example 1, a vinyl chloride polymer was prepared in the same manner as in Example 1, except that the tip speed was changed under the conditions shown in Table 1 below.

Example 3

In Example 1, a vinyl chloride polymer was prepared in the same manner as in Example 1, except that the tip speed was changed under the conditions shown in Table 1 below.

Example 4

In Example 1, a vinyl chloride polymer was prepared in the same manner as in Example 1, except that the tip speed was changed under the conditions shown in Table 1 below.

Example 5

In Example 1, a vinyl chloride polymer was prepared in the same manner as in Example 1, except that the tip speed was changed under the conditions shown in Table 1 below.

Example 6

In Example 1, a vinyl chloride polymer was prepared in the same manner as in Example 1, except that the tip speed was changed under the conditions shown in Table 1 below.

Comparative Example 1

In Example 1, a vinyl chloride polymer was prepared in the same manner as in Example 1, except that the tip speed was changed under the conditions shown in Table 1 below.

Comparative Example 2

In Example 1, a vinyl chloride polymer was prepared in the same manner as in Example 1, except that the tip speed was changed under the conditions shown in Table 1 below.

Comparative Example 3

In Example 1, a vinyl chloride polymer was prepared in the same manner as in Example 1, except that the tip speed was changed under the conditions shown in Table 1 below.

Comparative Example 4

In Example 1, a vinyl chloride polymer was prepared in the same manner as in Example 1, except that the tip speed was changed under the conditions shown in Table 1 below.

Comparative Example 5

When the polymerization conversion was 50%, a vinyl chloride polymer was prepared in the same manner as in Example 1, except that the tip speed of the stirrer blade was adjusted to 0.84 m/s.

division Initial tip speed
(m/s) Tip speed conversion point Tip speed after conversion (m/s) End point of maintaining tip speed Example 1 0.84 5% 1.05 reaction termination Example 2 0.84 5% 1.26 reaction termination Example 3 0.84 5% 1.47 reaction termination Example 4 1.47 - -
(maintaining the initial tip speed) reaction termination Example 5 0.84 40% 1.47 reaction termination Example 6 1.47 40% 1.05 reaction termination Comparative Example 1 0.84 - -
(maintaining the initial tip speed) reaction termination Comparative Example 2 0.84 5% 1.68 reaction termination Comparative Example 3 0.84 50% 1.05 reaction termination Comparative Example 4 1.05 50% 1.68 reaction termination Comparative Example 5 1.05 50% 0.84 reaction termination

Experimental Example 1: Evaluation of polymer particle properties, fogging properties, and reactor scale generation

The particle characteristics of the prepared polymer, fogging properties, and the amount of scale generation in the reactor were measured by the following measurement methods, respectively, and are shown in Table 2.

1) Measure average particle diameter (D ₅₀ ) and number of particles (Nc)

After the polymerization was completed, the polymer obtained was diluted to 0.05% by weight in deionized water to prepare a sample for measuring the average particle size, and then the average particle size was measured using a particle size meter (DC24000 UHR from CPS).

2) Measurement of fogging properties

To analyze the fogging properties, the generation of volatile organic compounds was measured, and the generation of volatile organic compounds was measured using a fogging tester (Horizon-FTS, Thermo Fisher Scientific, Inc.) in accordance with DIN 75-201 B. Specifically, 10 g of each of the above vinyl chloride polymers was placed in a cylinder, and the top of the cylinder was covered with aluminum foil and then heated at 100° C. for 16 hours. Thereafter, the volatile organic compounds collected on the surface of the aluminum foil were measured through the calculation of Equation 1 below.

[Equation 1]

Amount of volatile organic compounds generated (mg) = mass of aluminum foil after fogging test - mass of aluminum foil before fogging test

3) Measurement of scale generation

The amount of scale generation was measured with the amount filtered using 200mesh, and the amount of scale generation was shown as the following standard.

◎: When the amount of generation is very small

○: When the amount of generation is small

△: When the amount of generation is large

X: agglomeration

division Average particle diameter (D ₅₀ ) Number of particles (Nc) / L Amount of volatile organic compounds (mg) amount of scale Example 1 0.65 1.1 x 10 ¹⁵ 0.32 ◎ Example 2 0.69 9.6 x 10 ¹⁴ 0.34 ◎ Example 3 0.73 7.4 x 10 ¹⁴ 0.34 ◎ Example 4 0.80 7.0 x 10 ¹⁴ 0.35 ◎ Example 5 0.73 7.2 x 10 ¹⁴ 0.32 ○ Example 6 0.62 1.2 x 10 ¹⁵ 0.33 ◎ Comparative Example 1 0.61 1.1 x 10 ¹⁵ 0.36 ◎ Comparative Example 2 0.82 6.4 x 10 ¹⁴ - X Comparative Example 3 0.64 1.0 x 10 ¹⁵ 0.35 ○ Comparative Example 4 0.79 6.8 x 10 ¹⁴ 0.39 △ Comparative Example 5 0.66 9.4 x 10 ¹⁴ 0.35 ○

As shown in Table 1, in Examples 1 to 6, it can be seen that the amount of scale generation is very small compared to Comparative Examples 1 to 4, which suppresses the agglomeration between particles by controlling the tip speed according to the present invention when manufacturing the polymer. It can be seen that this is because

On the other hand, in the case of Comparative Example 2, in which the tip speed was controlled at the same conversion rate as in Examples 1 to 3, but changed to a value exceeding the specific tip speed range in the present invention, aggregation occurred to obtain a normal vinyl chloride-based polymer latex This was difficult, and this could be confirmed through the amount of scale generation.

In addition, it can be seen that Examples 1 to 6 have improved overall fogging properties compared to Comparative Examples 1 to 5, and through this, it can be seen that the vinyl chloride-based polymer prepared by the production method of the present invention has a low amount of volatile organic compounds. can As such, volatile organic compounds are harmful to the environment and human body, and the vinyl chloride-based polymer of the present invention can be variously applied as an eco-friendly material because the amount of harmful volatile organic compounds is low.

Experimental Example 2: Evaluation of plastisol formulation properties

In order to compare and analyze the plastisol viscosity characteristics and foaming properties of each of the vinyl chloride-based polymers prepared in Examples 1 to 6 and Comparative Examples 1 to 5, the physical properties of each vinyl chloride polymer were measured. The results are shown in Table 3 below.

First, each plastisol was prepared by stirring at 800 rpm for 10 minutes using a Werke mixer (EUROSTAR IKA) using a Werke mixer (EUROSTAR IKA) in a ratio of each of the vinyl chloride-based polymers and diisononyl phthalate (DINP). The viscosity, fogging properties and foaming properties of the plastisol were evaluated in the following way, and the evaluation results are shown in Table 2.

1) Viscosity measurement

Viscosity characteristics were measured for each of the plastisols using a Rheometer (AR2000EX peltier plate, TA Instruments) with a measuring tool 40 mm parallel plate and a measuring gap of 500 μm.

2) Measurement of foam properties

First, 70 parts by weight of diisononyl phthalate (DINP), 3 parts by weight of an azo-based foaming agent, and 2 parts by weight of a Ba/Zn stabilizer were added to 100 parts by weight of the vinyl chloride-based polymer, and 4 parts by weight at 700 rpm using a Werke mixer (EUROSTAR IKA). Each plastisol was prepared by stirring for minutes, and the thickness was measured after pre-gelling at 150°C and 60 seconds using the prepared plastisol oven (CH-8156, Mathis), and then at 220°C. After carrying out under the condition of , 120 seconds, the thickness was measured and the foaming properties were measured through the calculation of Equation 2 below.

[Equation 2]

Foaming properties = Thickness after conducting at 220℃, 120 seconds / Thickness after performing pre-gelling at 150℃, 60 seconds

Here, the foaming property may mean a foaming ratio.

division Viscosity (Pa s) Foam properties measurement parameters Example 1 12 5.7 Example 2 8 5.2 Example 3 7 5.3 Example 4 7 5.2 Example 5 10 5.6 Example 6 14 5.6 Comparative Example 1 27 5.9 Comparative Example 2 - - Comparative Example 3 25 5.8 Comparative Example 4 8 - Comparative Example 5 27 5.8

As shown in Table 2, the plastisols containing the vinyl chloride-based polymers of Examples 1 to 6 according to an embodiment of the present invention have low viscosity properties and foam at the same time as compared to Comparative Examples 1 to 5. It can be seen that the physical properties are improved.

Specifically, Comparative Example 1, in which the tip speed during polymerization was out of the numerical range according to an embodiment of the present invention, had a high viscosity and could not implement low-viscosity characteristics, and set the tip speed to the numerical range according to an embodiment of the present invention. It can be seen that even in the case of Comparative Example 3, which was adjusted at a time point exceeding 40%, the viscosity was high, so that the low-viscosity characteristic could not be realized.

In addition, in the case of Comparative Example 2, although the tip speed was adjusted at the time of conversion according to an embodiment of the present invention, the latex stability was lost as the tip speed was adjusted too high, and the latex agglomeration phenomenon (creaming) of the vinyl chloride-based polymer It was difficult to secure, and in the case of Comparative Example 4, it was possible to implement the low viscosity characteristic by controlling the tip speed according to an embodiment of the present invention up to 50%, but this was not maintained until the end of the reaction, and the time point to the latter part of polymerization In the case of foam measurement, due to a decrease in latex stability as the tip speed was increased, it was impossible to measure the foaming ratio due to an open cell. In addition, the plastisol produced by adjusting the tip speed according to an embodiment of the present invention to 50%, and not maintained until the end of the reaction, and by lowering the tip speed at the point of transition to the latter half of polymerization, increases the viscosity, so that the plastisol produced has a low point. It can also be seen that the characteristic cannot be implemented.

In contrast, the polymers of Examples 1 to 6 control the tip speed at the time of conversion according to an embodiment of the present invention, and all plastisols prepared by maintaining this have low viscosity characteristics, but the foam cell bursts. The foaming properties were improved to an excellent level without any problems.

As described above, since the plastisol containing the vinyl chloride-based polymer prepared according to an embodiment of the present invention has low viscosity characteristics and improved foaming properties, it is possible to provide a plastisol that is easy to process.

Claims (9)

Controlled so that the tip speed of the stirrer blade is 1.2 to 1.47 m/s at the time when the conversion rate is 0 to 40% after the start of the emulsion polymerization reaction,
A method for producing a vinyl chloride-based polymer that maintains the controlled tip speed until the polymerization reaction is completed.
delete According to claim 1,
The method for producing a vinyl chloride-based polymer by controlling the tip speed at the time when the conversion rate is 5 to 10%.
According to claim 1,
The emulsion polymerization reaction is a method for producing a vinyl chloride-based polymer to start the reaction by adding a vinyl chloride-based monomer to a reactor filled with a polymerization initiator and an emulsifier.
5. The method of claim 4,
The emulsifier is a method for producing a vinyl chloride-based polymer comprising 0.02 to 0.1 parts by weight based on 100 parts by weight of the vinyl chloride-based monomer.
5. The method of claim 4,
The emulsifier comprises at least one of alkane sulfonate, alpha-olefin sulfonate, straight chain alkylbenzene sulfonate, alkane sulfate, alkane ethoxylated sulfate, alkane ether sulfate, and alkylbenzene sulfonic acid. A method for producing a polymer.
5. The method of claim 4,
The emulsifier is a method for producing a vinyl chloride-based polymer comprising an alkane sulfate.
The average particle diameter (D ₅₀ ) is 0.69 to 0.8 μm,
The number of particles (Nc) of 7.0 × 10 ¹⁴ /L to 1.2 × 10 ¹⁵ /L of the vinyl chloride-based polymer prepared by the method of claim 1.
It contains the vinyl chloride-based polymer of claim 8,
A vinyl chloride-based plastisol having a viscosity of 5 to 20 Pa·s.