KR101715450B1 - Method for polymerizing paste PVC and forming material - Google Patents

Abstract

The present invention relates to a paste PVC polymerization method and a foamed molded article, and it is an object of the present invention to overcome the disadvantages of handling the defoaming agent due to the high viscosity of the conventional defoaming agent and the problem of remaining without evaporation during drying of the paste PVC latex, The specific liquid compound is introduced into the polymerization reactor and polymerized to prevent the deterioration of the heat releasing efficiency of the reflux condenser while maintaining the physical properties of the paste PVC to thereby secure a sufficient heat-separating ability. In addition, And can provide not only latex stability and cycle time reduction without seasonal deviation, but also foam molding products such as artificial leather, flooring, floor coverings, gloves, carpets and the like while reducing the maximum reaching temperature at the end of reaction .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a paste PVC polymerizing method,

The present invention relates to a paste PVC polymerization method and a foamed molded product, and more particularly, to a method for polymerizing paste PVC and a foamed molded product, , And further, by applying specific non-isothermal conditions, it is possible to maintain the degree of increase of the end-of-reaction temperature at a predetermined level and polymerize to shorten the stability and cycle time of latex without causing seasonal deviation in PVC properties And a foamed molded article comprising the paste PVC obtained by this method.

Vinyl chloride resin (hereinafter referred to as PVC) is divided into straight PVC and paste PVC according to the association structure determined in the manufacturing method. Straight PVC is prepared by suspension polymerization method with particle size of about 100 ~ 200㎛ and paste PVC is prepared by fine suspension polymerization, emulsion polymerization, or seed emulsion polymerization with powder particles of about 0.1 ~ 2㎛ size. Further, the straight resin is processed by the calender method, and the paste resin is processed by the casting method.

The paste vinyl chloride resin is prepared by adding a vinyl chloride monomer alone or a mixture of a vinyl chloride monomer and a monomer copolymerizable therewith (these are collectively referred to as a vinyl chloride monomer) in an aqueous medium with an emulsifier and an oil-soluble polymerization initiator, Suspension polymerization is carried out. If necessary, auxiliary dispersants such as higher alcohols and higher fatty acids may be used.

In general, 80 to 98% by weight of the vinyl chloride monomer used in the paste vinyl chloride resin polymerization is converted into a paste vinyl chloride resin, and the remaining unreacted monomer is removed to obtain a latex having a solid content of 50% by weight. The paste vinyl chloride resin is obtained by spray drying the latex from a spray dryer.

High temperature steam of 200 캜 is required to evaporate about 50% by weight of water in the latex during the drying process. The paste PVC is one of general-purpose resins widely used for everyday household goods such as architectural materials, wallpaper, artificial leather, woven fabrics, sheets and films, and industrial applications.

The vinyl chloride monomer is emulsified or emulsion-polymerized by adding an emulsifier or a water-soluble initiator in an aqueous medium by another polymerization method. In seed emulsion polymerization, seeds of two different average particle sizes are injected at the beginning of polymerization and vinyl chloride monomers are grown while reacting with the seed to produce final latex particles.

During the paste PVC polymerization reaction, many bubbles are generated. When the bubbles are excessively generated and the level of the inside of the reactor is completely filled up, the feed line of the polymerization reactor and the reflux condenser line are clogged.

At this time, when the foam flows into the reflux condenser and is filled, the cooling opportunity of the vinyl chloride monomer is reduced, and the heat-removing performance is lowered. In addition, the PVC particles contained in the foam adhere to the wall of the reflux condenser tube to form scale, and it takes much time and effort to remove it.

In order to solve such a problem, the defoaming agent is added to remove the foam, but the paste PVC remains unremoved upon drying, which adversely affects the physical properties of the paste PVC, so that the input is very limited . The defoaming agent is usually a mineral oil type or silicone, which usually has a viscosity of 1,000 to 3,000 cp (at 20 ° C). In addition, since it is an oil component, it is not soluble in water. Therefore, in order to dilute it, a dispersing system should be added. However, its use is limited because it affects the final PVC particle shape. Therefore, there is a limitation in adjusting the input flow rate and the dilution concentration to be supplied during the polymerization through the line, so that it is difficult to accurately input the desired amount.

In fact, in the early and middle stages of polymerization, the production of foam in the reactor is suppressed by the continuous introduction of vinyl chloride monomer, but at the end of the polymerization in which the introduction of the vinyl chloride monomer is completed, measures for foam removal are still required because PVC conversion is 70 to 75% At this point, the heat generated by the Trommsforf effect is rapidly increased, and the temperature of the reactor is also rapidly increased.

The degree of increase of the end-of-reaction temperature is elevated by more than 10 ° C in the summer due to the variation in the heat capacity of the reactor due to the temperature difference of the cooling water during the season, and seasonal variation of the PVC properties may be caused.

Further, when the unreacted vinyl chloride monomer recovery step is carried out during the polymerization, the cycle time is increased by at least 1 hour, so that the productivity is inevitably reduced. After completion of the polymerization, the latex is transferred from the reactor to the storage tank and then the vinyl chloride monomer recovery process At this time, latex coagulation phenomenon frequently occurs due to deterioration of latex stability during the transfer process. In order to prevent such latex agglomeration, if the end-of-reaction temperature is raised, the content of the vinyl chloride monomer in the particle can be reduced due to the rapid increase of the initiator activity due to the high temperature, and the consumption rate of the unreacted vinyl chloride monomer is rapidly increased, The conversion rate of the reactor is increased and thus the pressure drop rate in the reactor is increased, thereby reducing the cycle time.

As a result, there is a need for a technique for preventing the phenomenon that the reflux condenser is lowered in the heat removal efficiency at the end of the reaction due to bubbles so that the degree of increase in the end temperature of the reaction is maintained at a constant level without seasonal variations.

Therefore, it is an object of the present invention to overcome the cost disadvantages of handling defoaming agents of the prior art defoaming agents and the problems that remain unevaporated during drying of the paste PVC latex, and at certain times during the polymerization a specific liquid compound is introduced into the polymerization reactor, Thereby maintaining the physical properties of the paste PVC and effectively preventing foaming in the reflux condenser to prevent the deterioration of the heat-removing performance, thereby preventing the deterioration of the heat-removing efficiency of the reflux condenser and ensuring sufficient heat- separating ability. In addition, , And can provide a latex stability and a cycle time shortening without seasonal deviation, and a foamed molded article comprising the paste PVC obtained by the method.

In order to solve the above-mentioned problems, the present invention provides a process for producing polylactic acid, which comprises heating the polylactic acid to 80 ° C at the time when the reactor pressure change (ΔP) is 0.5 KG / cm 2 or more under isothermal or elevated temperature conditions, And controlling the temperature to be lowered by heating.

The present invention also provides a foamed molded article comprising the paste PVC obtained by the above-mentioned method.

The paste PVC polymerization method and the paste PVC of the present invention overcome the problem of costly handling due to the high viscosity of the conventional defoaming agent and the problem of remaining without evaporation during drying of the paste PVC latex, To prevent the deterioration of the heat removal efficiency of the reflux condenser while maintaining the physical properties of the paste PVC, thereby securing a sufficient heat-retaining ability. In addition to confirming the condition that the pressure does not rise above the reactor allowable level, The present invention can be applied to the production of foamed molded articles such as artificial leather, topsheet, wallpaper, flooring material, gloves, and carpets while reducing the maximum temperature at the end of the reaction, as well as providing latex stability and cycle time reduction.

Hereinafter, the present invention will be described in more detail.

In the present invention, during the paste-PVC polymerization, a liquid compound having a viscosity of 10 to 50 cP or less (at 20 ° C) at a time of completion of the introduction of the vinyl chloride monomer is added and the reactor pressure change (ΔP) Is at least 0.5 KG / cm < 2 >, the temperature is controlled to be 80 DEG C, and when the temperature reaches 80 DEG C, the temperature is controlled to the pre-temperature polymerization temperature.

Even when the liquid compound is used without dilution, the effect of the liquid compound as a defoaming agent is not impaired. However, since the amount of the liquid compound used is very small, it is preferable to dilute the liquid compound with water in consideration of ease of introduction.

Although the dilution ratio is not specified, the dilution ratio is high, and the higher the proportion of water in the latex resin is, the more the amount of water to be removed in the drying step is increased and the drying cost burden is increased. If the amount of water is too much, , The polymerization reaction may be delayed. For example, the dilution ratio may be 1: 10-1: 50 by weight.

The total amount of the liquid compound (before dilution) may be 0.0005 parts by weight or more, or 0.0005 to 0.005 parts by weight based on 100 parts by weight of the vinyl chloride monomer, and the remaining amount after the drying step Adverse effects on the physical properties of the soap paste PVC resin, particularly the foaming properties, can be prevented.

In addition, considering that the pressure of the reactor begins to drop from the point of time when the monomer consumption in the reactor becomes lower than the saturation pressure after the completion of the charging of the vinyl chloride monomer to the isothermal condition or the temperature increase due to the Trommsforf effect, .

The temperature can be adjusted to 80 ° C, for example, when the reactor pressure change (ΔP) is 0.5 kg / cm 2 or more, 0.5 to 1.0 kg / cm 2, or 0.5 kg / cm 2 under isothermal or elevated temperature conditions during polymerization after completion of charging of the vinyl chloride monomer And when the temperature reaches 80 DEG C, the temperature is reduced to the above-mentioned polymerization temperature range.

When the vinyl chloride monomer is present at a temperature higher than the saturation pressure in the reactor, the pressure is also constant if the inner temperature of the reactor is maintained constant. However, since the pressure fluctuates when the temperature is changed, , The time point at which the temperature control is performed is limited to a case where no temperature drop occurs, that is, the case occurs under isothermal or elevated temperature conditions.

This is also related to the polymerization conversion rate. Conventionally, at the end of the reaction, that is, when the PVC conversion rate exceeds 70 to 75%, the temperature is rapidly increased due to the Trommsforf effect, . On the other hand, if the reduction of the heat removal efficiency of the reflux condenser is prevented by removing the bubbles by the liquid compound used in the present invention, the degree of increase of the temperature is greatly reduced. Generally, the temperature of the reactor is controlled to such an extent that the temperature is maintained at 20 ° C in the hot summer and the temperature is maintained in the cold winter. Therefore, it is possible to arbitrarily adjust the temperature at the end of the reaction, so that the temperature control process can be performed to shorten the PVC conversion rate to 80 ~ 85%, and the process can be performed without any seasonal variation.

For reference, in the present invention, the term " reactor pressure change (DELTA P) " refers to the degree of the downward fluctuation of the reactor pressure, unless otherwise specified, and the term " completion time of vinyl chloride monomer addition " It means that the input flow rate is automatically controlled according to the intensity of the reaction based on the heat releasing ability of the reactor at the time when the positive input is completed.

The liquid compound may be introduced through a reflux condenser provided in a paste PVC polymerization reactor. In particular, the liquid compound may be filled in the reflux condenser to fill the void, thereby reducing the chance of cooling the vinyl chloride monomer and deteriorating the heat- It is more preferable to divide and input at specific intervals.

As the liquid compound, for example, aliphatic alcohols having a viscosity of 10 to 50 cP or less (at 20 ° C) and having 8 to 10 carbon atoms may be most suitable for the present application. When the number of carbon atoms is 10 or more, it does not dissolve in water. Conversely, when the number of carbon atoms is 8 or less, the function of removing bubbles is lost.

The total amount of the liquid compound (before dilution) may be 0.0005 parts by weight or more, or 0.0005 to 0.005 parts by weight based on 100 parts by weight of the vinyl chloride monomer, and the remaining amount after the drying step Can be prevented from adversely affecting the physical properties of the soap paste PVC resin, particularly the foaming properties.

The above-described split injection may be, for example, 3 to 4 times of injection at 20 to 30 minute intervals.

The unreacted compound in the liquid compound has the advantage that it evaporates along with water vapor during paste PVC drying (for example, spray drying), and does not adversely affect the physical properties of the paste PVC.

The paste PVC polymerization is, for example, one in which 0.001 to 0.01 part by weight of a polymerization initiator and 0.5 to 2.0 parts by weight of an anionic surfactant are added to a polymerization reactor based on 100 parts by weight of a vinyl chloride monomer and subjected to fine suspension polymerization, emulsion polymerization or seed emulsion polymerization .

In the seed emulsion polymerization, seeds different in two kinds of average particle diameters are injected at the beginning of polymerization, and the vinyl chloride monomer grows while reacting with the seed to prepare final latex particles. The first seed is prepared by adding a vinyl chloride monomer, an emulsifier and an oil-soluble initiator, homogenizing the mixture using a rotor-stator type homogenizer pump, and polymerizing the mixture. The first seed has an average particle diameter of about 0.4 to 1.5 μm, The seed is prepared by emulsion polymerization and has an average particle size of about 0.1 to 0.4 μm. Also in this case, an auxiliary dispersing agent such as a higher alcohol or a higher fatty acid may be used, if necessary. That is, it may be necessary to homogenize the first seed using the homogenizer pump of the rotor-stator type in the seed emulsion polymerization.

In addition, the micro suspension polymerization method is advantageous in that the heat of polymerization can be easily removed, and the polymer can be obtained in a size of about 0.1 to 2 μm, which is a convenient size for use.

In the micro suspension polymerization method, deionized water, a vinyl chloride monomer (or a mixture of two comonomers), a surfactant, an auxiliary surfactant, and a polymerization initiator are mixed with stirring, and then the high-pressure homogenizer is operated to transfer the reactants to the reactor The reaction is allowed to proceed to the reaction temperature. After completion of the reaction, spray drying is performed to obtain a powdery paste-like vinyl chloride resin. During the micro suspension polymerization, a homogenizer may be operated to produce homogeneous monomer droplets.

The high-pressure homogenizer can adjust the droplet size of the vinyl chloride monomer through mechanical operation of a mixture of vinyl chloride monomer, polymerization initiator, surfactant, deionized water, etc. before the polymerization reaction.

For example, a monomer capable of copolymerizing with vinyl chloride or vinyl chloride, a polymerization initiator, and a surfactant are mixed with strong stirring, and the mixture is passed through the high-pressure homogenizer to form a small droplet of 0.05 to 1.5 탆 into the reactor. To 65 占 폚 to give a paste vinyl chloride resin.

The type and shape of the reactor, stirrer, baffle, etc. used in the present invention are not particularly limited, and an apparatus used for the fine suspension polymerization or emulsion polymerization of a conventional vinyl chloride monomer can be used.

Examples of the anionic surfactant include linear fatty acids having 6 to 20 carbon atoms, branched fatty acids having 6 to 20 carbon atoms, alkylsulfonic acids, alkylarylsulfonic acids, sulfosuccinic acid esters, alkyl sulfates, alkyldisulfonic acid diphenyl oxides And ammonium salts of alkyldisulfonic acid diphenyl oxides can be used, but they are usually selected according to the application of the product.

The vinyl chloride monomer is a mixture of a vinyl chloride monomer alone or a monomer capable of copolymerizing with a vinyl chloride monomer. Examples of the monomer copolymerizable with the vinyl chloride monomer include vinyl esters, aromatic vinyl compounds, acrylic acid monoolefins, Halide. ≪ / RTI >

The amount of the polymerization initiator used varies depending on the polymerization temperature, the reaction time, the kind of the polymerization initiator, and the like. For example, an oil-soluble initiator and a water-soluble initiator can be used. Specifically, the oil-soluble initiator is selected from the group consisting of dipentyl peroxide, di-3,3,5-trimethylhexanoyl peroxide, dira lauroyl peroxide, diisopropyl peroxy dicarbonate, di- 2-ethylhexyl peroxydicarbonate, azobisisobutyronitrile, azobis-2-methylbutyronitrile, or azobis-2,4-dimethylvaleronitrile, and the water-soluble initiator may be potassium persulfide, Ammonium sulphide or hydrogen peroxide.

The polymerization initiator is preferably contained in an amount of 0.001 to 2.0 parts by weight based on 100 parts by weight of the total amount of the vinyl chloride monomer. When the content of the polymerization initiator is less than 0.001 part by weight, the polymerization reactivity is deteriorated. There is a problem that it is difficult to heat the polymerization reaction heat.

As another example, the polymerization time can be shortened by controlling the initial reactivity using an oxidation-reduction initiator system. Specific examples of the oxidation-reduction initiator include copper sulfate and ascorbic acid. When the vinyl chloride resin is prepared by an isothermal reaction method while controlling the initial reactivity using such an oxidation-reduction initiator, the reaction stability is improved and the foam properties are improved and the reaction time is shortened.

When the oxidation-reduction initiator system is used, the initiator decomposition may be activated by continuously adding it during the reaction. If all of the initiator is added all at once, a side effect of suppressing the generation of free radicals may occur.

In the present invention, the reaction mixture is prepared from the above-mentioned components, and then the temperature change (ΔP) in the reactor is increased from 0.5 kg / cm 2 or more to 80 ° C. under isothermal or elevated temperature conditions during polymerization of the reaction mixture, The temperature can be controlled so that the temperature is lowered to the pre-heating temperature. When the non-isothermal polymerization is carried out within this range, the conversion rate of the vinyl chloride monomer to the PVC is further increased, and the latex stability is further increased, and the quality deviation can be prevented by adjusting the terminal temperature at the end of the reaction.

For reference, the reaction can be terminated within a shortened time in the range of 80 to 85% conversion after thermostatting at 70% or more, or 70 to 80%, of the polymerization conversion rate.

According to the above method, not only the polymerization time can be shortened, but also the maximum reached temperature at the end of the reaction can be reduced. If necessary, the spray-dried paste may be classified or pulverized.

In order to prepare the plastisol using the powder paste of the present invention, a conventionally used method for preparing the vinyl chloride resin plastisol can be used. That is, the vinyl chloride powder paste may contain additives such as plasticizers such as heat stabilizers, fillers, foaming agents, foaming accelerators, surfactants, viscosity reducing agents, adhesion imparting agents, Other resins or the like may be blended as required and mixed sufficiently to homogeneity using a planetary mixer, a kneader, a roller, a brain ball, or the like to prepare a plastisol.

The plasticizer to be used in the preparation of the plastisol is not particularly limited, and examples thereof include dibutyl phthalate, diisobutyl phthalate, diheptyl phthalate, di- (2-ethylhexyl) phthalate, diphthalic acid- Phthalic acid derivatives such as dicyclohexyl phthalate, dinonyl phthalate, diisodecyl phthalate, diundecyl phthalate, dicyclohexyl phthalate, butyl benzyl phthalate and diphenyl phthalate, isophthalic acid derivatives, adipic acid derivatives, sebacic acid derivatives, Phthalic acid derivatives, pyromellitic acid derivatives; Itaconic acid derivatives, oleic acid derivatives; Phosphoric acid derivatives, glycol derivatives, glycerin derivatives, adipic acid-based polyester, sebacic acid-based polyester, and the like. These plasticizers may be used singly or in combination of two or more. The blending amount of the plasticizer can be appropriately adjusted by those skilled in the art according to the application.

The powder paste of the present invention may be prepared by mixing a vinyl chloride resin for mixing having an average particle diameter of 10 to 60 占 퐉, which is known as a mixed resin, a diluted resin, etc., for the purpose of improving the hardness and glossiness of the molded article.

The method of obtaining the foam from the plastisol of the present invention may be carried out by a method commonly used in this field and is not described here.

The paste PVC obtained by the above-mentioned method can also maintain the expansion ratio when applied to foam molding. For reference, it is applicable to the manufacture of artificial leather, carvings, wallpaper, floor coverings, gloves and carpets.

Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples illustrate the invention

And the contents of the present invention are not limited by the following examples.

Example 1

Paste PVC latex was prepared by emulsion polymerization using two kinds of seed particles of different sizes.

Specifically, the first seed is prepared by adding a vinyl chloride monomer, an emulsifier, and an oil-soluble initiator, homogenizing the mixture using a rotor-stator type homogenizer pump, and polymerizing the mixture. The first seed has an average particle diameter of about 0.66 μm, 2 Seed is emulsion polymerization (the emulsifier used is sodium laurylsulfate (SLS), the total amount of which is 2.5 w / w in 100 w / w of vinyl chloride monomer, 0.1 wt. 0.9 part by weight was continuously added thereto for 4 hours, and after completion of polymerization, 1.5 weight parts were added). The average particle diameter was about 0.19 탆.

The first seed (large) and the second seed (small) were charged at a weight ratio of 1: 0.5 to a 500 L high-pressure reactor equipped with a reflux condenser (performed in July when the cooling water temperature was 22.12 ° C) An oxidation-reduction initiator was used. The concentration of ascorbic acid was 0.44% (concentration) at the beginning of the polymerization in the aqueous solution state of 4% (concentration), and the concentration of ascorbic acid was 0.44% (concentration) After the completion of the temperature rise in the aqueous solution state (at the point of time when the polymerization temperature reached 57.5 ° C.), the reactor was supplied with a flow rate of 0.8 kg / hr for 45 minutes. Then, a programmed reaction mode was set so that the calorific value did not exceed the reactor heat- So that the flow rate of the ascorbic acid aqueous solution is automatically adjusted.

While the polymerization was progressing at 57.5 ° C, vinyl chloride monomer (100 kg was added in advance of polymerization at the initial stage of polymerization and then 115 Kg was continuously supplied for 3 hours and 30 minutes from the completion of the temperature increase) Through the line connected to the reflux condenser tube at the point of time when the continuous supply is completed (at the time when the amount set by the prescription is completed under a system in which the input flow rate is automatically controlled by the intensity of the reaction based on the heat- 99 g of water was mixed with 11 g (corresponding to 0.0005 part by weight based on 100 parts by weight of vinyl chloride monomer) of n-octyl and decyl mixed alcohol having a concentration of 100% as an alcohol and having a viscosity of 10 to 50 cP (mixing ratio 1: 10 weight ratio of aliphatic alcohol-water mixture diluted three times at 20-minute intervals and emulsion polymerization was carried out.

After completion of the addition of the vinyl chloride monomer, the reaction mode setting was changed to 80 ° C when the reactor pressure was lowered at the isothermal temperature or at the time of temperature rise, that is, when the ΔP was 0.5 KG / cm 2. When the internal temperature of the reactor reached 80 ° C The process of lowering the mode setting temperature again to 57.5 ° C was performed once. When the reactor pressure reached 3.5 KG / cm < 2 >, a blow down process for transferring the latex was performed.

After completion of the polymerization, the polymerization time (the time required for the reactor pressure to reach 3.5 kG from the time of the introduction of the oxidation-reduction initiator) and the maximum temperature reached at the end of the reaction from the point after the polymerization conversion rate of 70% were recorded. The latex obtained was measured for stability of the latex by using 1,2-dichloroethane (EDC) in the following manner and then spray-dried to obtain a vinyl chloride-based powder phase.

<Measurement of latex stability>

10 ml of 1,2-dichloroethane (EDC) was added to 220 g of the latex, and the mixture was stirred at 1000 rpm and the time (sec) required for agglomeration of the latex was measured.

Example 2

A vinyl chloride type powdery phase was prepared from latex polymerized in the same manner as in Example 1 except that the cooling water temperature of the reflux condenser was changed to 5.09 ° C in January.

Example 3

In Example 1, 11g (0.0005 parts by weight of 100 parts by weight of vinyl chloride monomer) of a mixed alcohol of n-octyl alcohol and decyl alcohol (mixing ratio 1: 1) was mixed with 539g of water and diluted to a weight ratio of 1:50, A vinyl chloride type powdery phase was prepared from latex polymerized in the same manner as in Example 1 except that the aliphatic alcohol and water mixture was added in portions.

Comparative Example 1

Except that the aliphatic alcohol was not added in the above Example 1 and accordingly the reaction temperature setting mode was not changed at the completion of the polymerization (until the reactor pressure reached 3.5 KG / cm 2 at the point of time when the conversion rate reached 80 to 85% , A vinyl chloride type powdery phase was prepared from the latex polymerized in the same manner as in Example 1.

Comparative Example 2

A vinyl chloride type powdery phase was prepared from latex polymerized in the same manner as in Comparative Example 1 except that the cooling water temperature of the reflux condenser in Comparative Example 1 was 5.09 캜.

Comparative Example 3

The procedure of Example 1 was repeated except that the reaction temperature setting mode was not changed during the completion of the polymerization (until the reactor pressure reached 3.5 KG / cm &lt; 2 &gt; A vinyl chloride powder phase was prepared from the polymerized latex.

Comparative Example 4

In Example 1, 5,489 g of water was mixed with 11 g (0.0005 part by weight based on 100 parts by weight of vinyl chloride monomer) of a mixed alcohol of n-octyl alcohol and decyl alcohol (mixing ratio 1: 1) to dilute the mixture at a weight ratio of 1: g of an aliphatic alcohol-water mixture was added in portions to prepare a vinyl chloride type powdery phase with the latex polymerized in the same manner as in Example 1.

The physical properties of Examples 1 to 3 and Comparative Examples 1 to 4 are summarized together in Table 1 below.

division Example Comparative Example One 2 3 One 2 3 4 Amount of aliphatic alcohol-water mixture (g) 110 110 550 X X 110 5,500 Polymerization time (minutes) 270 253 274 299 272 278 287 Reflux condenser cooling water temperature (℃) 22.12 5.09 22.25 22.34 5.15 21.91 21.99 Whether aliphatic alcohol is added or not O O O X X O O Maximum end temperature of reaction (℃) 80 80 80 86.7 72.32 74.43 80 Latex stability (sec) 141 152 140 145 65 97 144

As shown in Table 1, in the case of Examples 1 and 2 polymerized according to the present invention, it was possible to control the temperature arbitrarily at the end of the reaction by applying the partial feeding method of the terminal aliphatic alcohol at the end of the reaction, The step of raising and lowering the temperature to 80 캜 was performed, whereby the stability of latex was improved and the cycle time was shortened as compared with Comparative Example 3.

In addition, by maintaining the maximum reached temperature at the end of the reaction stably, it is possible to reduce the variation in the latex stability due to the maximum temperature difference at the end of the reaction and the deviation of the physical properties such as viscosity and foaming, i.e. seasonal deviation of the paste PVC resin quality. Specifically, in Table 1, it was found that the deviation between the stability of latex of Example 1 and Example 2 was less than that of the latex stability of Comparative Example 1 and Comparative Example 2.

Further, as a result of comparison between Examples 1-3 and Comparative Example 4, it was found that as the dilution ratio of the liquid compound increases in the diluted concentration range of the liquid compound, the amount of water increased, It was found that it is preferable to lower the dilution ratio as much as possible because it causes retardation of the polymerization at the end of the reaction.

Claims (15)

Paste During the polymerization of PVC, an aliphatic alcohol having a viscosity of 10 to 50 cP (at 20 ° C) and having a carbon number of 8 to 10 was added at the completion of the introduction of the vinyl chloride monomer, and the reactor pressure change (ΔP) Kg / cm &lt; 2 &gt; and temperature is controlled to be 80 DEG C, and when the temperature reaches 80 DEG C, the temperature is adjusted to the pre-polymerization temperature, and the amount of the aliphatic alcohol is 0.0005 to 0.005 wt% based on 100 wt% &Lt; / RTI &gt;
The method according to claim 1,
Wherein the temperature control is performed once at a polymerization conversion rate of 70% or more, and then the reaction is terminated within a conversion ratio of 80 to 85%.
The method according to claim 1,
Wherein the aliphatic alcohol is introduced through a reflux condenser provided in a paste PVC polymerization reactor.
delete delete The method according to claim 1,
Wherein the aliphatic alcohol is diluted with water at a weight ratio of 1:10 to 1:50.
The method according to claim 1,
Wherein said step of introducing is carried out three to four times at intervals of 20 to 30 minutes.
The method according to claim 1,
Wherein the unreacted compound in the aliphatic alcohol is evaporated during the paste PVC drying process.
The method according to claim 1,
Wherein the paste PVC polymerization is carried out in the presence of 0.001 to 0.01 part by weight of a polymerization initiator and 0.5 to 2.0 parts by weight of an anionic surfactant based on 100 parts by weight of a vinyl chloride monomer, Polymerization method.
10. The method of claim 9,
Examples of the anionic surfactant include linear fatty acids having 6 to 20 carbon atoms, branched fatty acids having 6 to 20 carbon atoms, alkylsulfonic acids, alkylarylsulfonic acids, sulfosuccinic acid esters, alkyl sulfates, alkyldisulfonic acid diphenyl oxides An alkali metal salt and an ammonium salt of an alkyldisulfonic acid diphenyl oxide.
The method according to claim 1,
The vinyl chloride monomer is a mixture of a vinyl chloride monomer alone or a monomer copolymerizable with a vinyl chloride monomer, and the monomer copolymerizable with the vinyl chloride monomer is a vinyl ester, an aromatic vinyl compound, an acrylic acid, a monoolefin, and a vinylidene halide Selected from the group consisting of polypropylene and polypropylene.
10. The method of claim 9,
The polymerization initiator may be selected from the group consisting of dipentyl peroxide, di-3,3,5-trimethylhexanoyl peroxide, dilauryl peroxide, diisopropyl peroxy dicarbonate, di-2-butyl peroxy dicarbonate, Characterized by being at least one selected from the group consisting of azobisisobutyronitrile, azobis-2-methylbutyronitrile, azobis-2,4-dimethylvaleronitrile, potassium persulfate, ammonium persulfate and hydrogen peroxide By weight.
10. The method of claim 9,
Wherein the micro suspension polymerization or the seed emulsion polymerization comprises a homogenization treatment step.
A foamed molded article comprising the paste PVC obtained by the method of claim 1.
15. The method of claim 14,
Wherein the foamed molded article is selected from artificial leather, topsheet, wallpaper, floor coverings, gloves, and carpets.