KR101410547B1 - A method for preparing PVC with high productivity and thermal stability - Google Patents

Abstract

The present invention relates to a method for producing a vinyl chloride resin having high productivity and improved thermal stability. In the step of producing a vinyl chloride resin by suspension polymerization, a polymerization initiator different in polymerization temperature is added, By controlling the injection amount, it is possible to reduce the whiteness due to the use of the low-efficiency initiator and to solve the problem caused by the incoherent heat of the heat, thereby increasing the production amount.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preparing a vinyl chloride resin having high productivity and improved thermal stability,

The present invention relates to a method for producing a vinyl chloride resin having high productivity and improved thermal stability. In the step of producing a vinyl chloride resin by suspension polymerization, a polymerization initiator different in polymerization temperature is added, The present invention relates to a method of controlling an input amount.

Vinyl chloride resins are inexpensive, and have properties such as excellent processability, chemical resistance, durability, and insulation, and are thus widely used for pipes, wallpaper, and window frames. However, the vinyl chloride resin has a low stability due to light or heat, and is easily oxidized or decomposed. This problem is mainly due to the high concentration of the residual initiator in the resin after polymerization due to the low efficiency of the initiator. In order to use the initiator having high efficiency, it is difficult to remove the heat generated during the polymerization reaction.

As a conventional technique for solving such problems, a method of using two or more kinds of initiators in combination to distribute the reaction heat evenly during the reaction or adjusting the reaction temperature so that the reaction heat is evenly distributed has been used. However, in the case of an initiator having a long half-life period for the latter reaction, there is a problem that the reactivity is low due to low reactivity and remains after the completion of the reaction, and when the reaction temperature is changed during polymerization, the polymerization degree is difficult to control. In order to solve this problem, in Akzo nobel, continuous injection of a peroxide initiator having a fast initial reaction is continuously injected during polymerization in domestic patents 0603684 and 0965925, the content of the initiator is increased, the content of the initiator is decreased, Heat stability was solved. In addition, the extinction of the vinyl chloride monomer rapidly proceeded with the continuous introduction of the initiator, and the pressure reduction time point became faster and the polymerization time was also shortened.

However, in this case, only initiators having a high reactivity with a half-life of 0.05 to 1.0 hour at the reaction temperature can be used in a limited manner, and since a high initiator activity tends to cause a reaction during the injection, a scale is generated in the reactor and the piping There is a problem that special injection equipment is required to prevent such a problem.

As described later, in the present invention, an initiator having a relatively wide half-temperature range is introduced into the reactor before the reaction so as not to have disadvantages of the prior art, and in order to utilize the given limit heat- A method of producing a resin by keeping the generation of reaction heat constant during the reaction by using a reaction modifier of a kind or more. In this case, since the initiator can be used in a maximum amount under a limited heat-separating ability, the amount of production can be increased. On the other hand, by using a quick initiator as compared with the conventional one, the residual initiator is not left and the thermal stability is improved. It is possible to produce using the existing facilities without using the existing facilities.

As an example of using a regulator during the reaction, Korean Patent Application No. 2005-7024687 discloses a method of preparing a (co) polymer in which the number of fish-eyes is reduced by controlling at least one controlling agent to control an organic peroxide initiator . However, this technique is different from the intention of the present invention only in the method of reducing the number of fish eyes by controlling the activity of the initiator at the initial stage of the reaction.

In the present invention, the content of the initiator remaining after the completion of the reaction is lowered by using a high-efficiency initiator and the excessive reaction heat generated by the high-efficiency initiator is stably maintained below the heat-releasing limit using the reaction control agent, And to provide a process for producing a resin which does not have problems of scale generation and control of degree of polymerization of existing methods by producing excellent vinyl chloride resin polymers.

That is, in the present invention, all or part of one or more reaction activity modifiers selected from the group consisting of free nitroxyl radicals, organic hydroperoxides, ethylenically unsaturated organic compounds, phenol-based hydrocarbon compounds, oximes, The reaction regulator may be added to the polymerization reaction material individually or in combination with one or more of other compounds, etc. Accordingly, it is an object of the present invention to provide a process for preparing a vinyl chloride resin, The reaction activity is controlled by controlling the reaction activity of the initiator using characteristics possessed by the reaction activity modifier and the vinyl chloride resin having excellent thermal stability related to discoloration can be produced by reducing the residual initiator.

According to the present invention, there is provided a method for producing a vinyl chloride resin by suspension polymerization while introducing a polymerization initiator different in polymerization temperature, characterized in that an activity regulator is used while controlling the injection timing and the amount

A method for producing a vinyl chloride resin is provided.

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

The present invention solves the problems caused by the low initiator efficiency and the high level of residual initiator of the prior art and overcomes the difficulties in controlling the reaction heat, and provides a novel vinyl chloride resin polymer production method. .

In order to achieve the above-mentioned technical characteristics, one or more reaction modifiers capable of controlling the reaction activity of the initiator used can be prepared by reacting one or more initiators having a half-life of 0.35 hours to 2.0 hours at the beginning of the reaction, The residual initiator content of the final resin obtained by injecting the resin so as not to exceed the heat-release limit determined in the reactor does not exceed 10 parts by weight based on 1 million parts by weight of the resin, and the time required for polymerization is from 120 minutes to at least 120 minutes It is possible to prepare a resin which does not exceed a maximum of 300 minutes by the following examples.

First, the present invention can be applied to any method of polymerizing a vinyl monomer containing a vinyl chloride monomer, and a method of polymerizing using a suitable initiator. When a water-soluble reaction modifier is used, it is particularly preferable for the suspension polymerization method. Examples of the vinyl chloride resin include copolymers of vinyl chloride homopolymers and other monomers copolymerizable with vinyl chloride, olefin compounds such as ethylene and propylene, vinyl esters such as vinyl acetate and vinyl propionate, unsaturated compounds such as acrylonitrile Unsaturated fatty acids such as acrylic acid, methacrylic acid, itaconic acid, and maleic acid, and anhydrides of these fatty acids may be used either singly or as a mixture of two or more thereof .

The initiator used in the production of the resin is used at the initial stage of polymerization by appropriately selecting an initiator having a half life of 0.35 to 2.0 hours under the polymerization temperature determined according to the degree of polymerization of the resin. The amount of the initiator to be fed into the reactor is increased by 5 to 50% by weight relative to the amount of the initiator used in the conventional polymerization. Accordingly, the use of 0.02 to 0.3 parts by weight per 100 parts by weight of the vinyl chloride monomer is suitable , And most preferably 0.03 to 0.15 part by weight.

At this time, when the amount of the initiator used is less than 0.02 parts by weight, the amount of the initiator for the monomer is lowered, and the reaction time is prolonged and the productivity is lowered. On the other hand, when more than 0.3 part by weight of the initiator is used, the efficiency of use of the initiator decreases due to the inter-initiator reaction, and the generation of particles proceeds too quickly, resulting in a problem that the particles can not be properly formed.

The above-mentioned polymerization temperature is generally determined by the degree of polymerization of the resin. Generally, the applied temperature is 55 to 60 ° C for a number average degree of polymerization of 1000 products, 61 to 65 ° C for a number average degree of polymerization of 800, In the range of 66 to 70 占 폚.

An initiator having a suitable half-life at the above polymerization temperature is as follows. Polymerization temperature 55 to 60 占 폚: α, α'-bis (neodecanoylperoxy) diisopropylbenzene, cumyl peroxyneodecanoate, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate , 1,1,3,3-tetramethylbutyl peroxyneodecanoate, bis (4-t-butylcyclohexyl) peroxy dicarbonate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, Di-2-ethoxyethyl peroxy dicarbonate, and di-2-ethylhexyl peroxydicarbonate, and azo compounds such as 2,2'-azobis (2,4-dimethylvaleronitrile) ≪ / RTI >

Polymerization temperature 61 to 65 占 폚: di-n-propyl peroxy dicarbonate, diisopropyl peroxy dicarbonate, 1,1,3,3-tetramethyl butyl peroxyneodecanoate, bis (4-t-butyl Cyclohexyl) peroxydicarbonate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, di-2-ethoxyethyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, t- At least one selected from peroxyneodecanoate, dimethoxybutyl peroxydicarbonate, bis (3-methyl-3-methoxybutyl) peroxydicarbonate, and t-butyl peroxyneodecanoate.

Polymerization temperature 66 to 70 占 폚: di-n-propyl peroxydicarbonate, diisopropyl peroxy dicarbonate, 1,1,3,3-tetramethyl butyl peroxyneodecanoate, bis (4-t-butyl Cyclohexyl) peroxydicarbonate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, di-2-ethoxyethyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, t- Peroxyneodecanoate, dimethoxybutyl peroxydicarbonate, bis (3-methyl-3-methoxybutyl) peroxydicarbonate, t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, And azo compounds such as 2,2'-azobis (isobutyronitrile) and dimethyl 2,2'-azobis (isobutyrate).

The reaction (activity) regulator suggested in the present invention may have various forms such as a stable free nitroxyl radical, an organic hydroperoxide, an ethylenically unsaturated organic compound, a phenol-based hydrocarbon compound, an oxime and a mixture thereof, Select and use. They are added to the reaction mixture during the reaction to react with the active radicals, thereby removing the radical activity and controlling the rate at which the initiator reacts with the monomer. When the reaction of the initiator is controlled to a certain level by using the reaction activity regulator, the reaction heat generated during the polymerization can be maintained at a constant level.

In order to control the polymerization method of the vinyl chloride resin, the reaction activity modifier of the initiator may be supplied to the reaction at least once to be mixed. Such physical property regulators may be added individually or in combination with one or more of other compounds.

In order to effectively control the activity of the initiator used, the reaction modifier is added in the initial stage of the reaction or in the middle of the reaction. In order to effectively use the reaction modifier, a minimum amount of the reaction modifier is added before the heat generation limit is exceeded to prevent the reaction heat from exceeding the heat generation limit. The heat limitation limit described herein means the maximum possible value for all the methods used for cooling the reactor. Specifically, when the cooling water is introduced through the jacket of the reactor, the point at which the lowest possible cooling temperature coincides with the jacket temperature And when the heat is removed through the heat exchanger, the maximum amount of the material circulated to the heat exchanger is regarded as reaching the heat removal limit criterion 100%.

Accordingly, the range of the heat-generating limit to which the reaction activity modifier used in the present invention is applied ranges from 80 to 99%, more preferably from 85 to 99%, and most preferably from 90% to 99%. When the reaction temperature is 65 ° C, when the heat-releasing limit reaches 90 to 99%, it is added when the jacket temperature is 5 to 0.5 ° C higher than the cooling water minimum temperature of 15 ° C. The introduction at a point higher than 5 ° C is not preferable because it slows the reaction time, and the introduction at a point lower than 0.5 ° C raises the temperature of the reactor, which is not preferable from the viewpoint of quality and safety. Further, even if the reaction modifier is added together with the initiator at the initial stage of the reaction, the polymerization is delayed because the radical reactivity of the initiator is lowered.

The amount of the active agent to be used varies depending on the kind of the controlling agent and the kind of the initiator. Typically, the amount of the active agent to be used is 0.1 to 50 parts by weight, 0.1 to 25 parts by weight, or 0.1 to 15 parts by weight, For example, 0.033 to 0.1 part by weight based on 1 part by weight of the initiator. If the amount of the reaction-controlling agent is more than the proper amount, most of the free radicals derived from the initiator are less reactive due to the radical-to-radical coupling reaction of the controlling agent, and the overall polymerization rate can be slowed down. Therefore, the amount of reaction modifier input should be used within the range of application. In addition, even when two or more kinds of regulators are mixed, the activity of the reaction is controlled irrespective of the mixing ratio. Therefore, only the amount of the mixture is used within the range of use.

When properly used, the activity of the reaction is immediately reduced, and the reaction heat can be controlled. This operation can be performed several times during the polymerization. This makes it possible to efficiently produce a vinyl chloride resin having high productivity and thermal stability.

Reaction controllers which can be used in the above polymerization include radicals containing a stable nitroxyl radical, i.e., = N-O- group. As a stable free radical, for example, a radical represented by the following formula can be used.

R1, R2, R3, R4, R1 'and R2' may be the same or different and are each a halogen atom such as chlorine, bromine or iodine, a linear, branched or cyclic Such as a saturated or unsaturated hydrocarbon-based group such as an alkyl or phenyl group, or an ester group -COOR, or an alkoxy group -OR, or a phosphonate group -PO (OR) 2, Rate), polybutadiene or polyethylene, or a polyolefin chain such as a polypropylene chain, but preferably represents any polymer chain that may be a polystyrene chain.

In this formula, R5, R6, R7, R8, R9 and R10 may be the same or different and may be selected from the same group as those for R1, R2, R3, R4, R1 'and R2' And may further represent an acid group such as a hydrogen atom, hydroxyl group -OH or -COOH or -PO (OR) ₂ , or SO ₃ H.

Representative free nitroxy radicals include 2,2,5,5-tetramethyl-1-pyrrolidinyloxy, 2,2,6,6-tetramethyl-1-piperidyloxy (TEMPO), N- Butyl-1-phenyl-2-methylpropylnitroxide, N-tert-butyl-1- (2-naphthyl) -2- methylpropylnitroxide, N-tert- N-tert-butyl-1-dibenzylphosphino-2,2-dimethylpropylnitroxide, N-phenyl-1-diethylphosphono-2,2-dimethylpropyl N-phenyl-1-diethylphosphono-1-methylethylnitroxide, N- (1-phenyl-2-methylpropyl) -1-diethylpropano- , 4-hydroxy-2,2,6,6-tetramethyl-1-piperidyloxy, 4-oxo-2,2,6,6-tetramethyl- 6-tri-tert-butylphenoxy, and the like.

In addition, the modifier that can be used in the present invention is hydroperoxide. Examples include, but are not limited to, methylhydroperoxide, ethylhydroperoxide, n-propylhydroperoxide, isopropylhydroperoxide, sec-butylhydroperoxide, isobutylhydroperoxide, 1-phenyl- -Hydroperoxyethane, benzyl hydroperoxide, methyl ethyl ketone hydroperoxide such as 2,2'-dihydropperoxy-2'-di-n-butyl peroxide and 2,2-dihydropor A mixture of cyclohexanone hydroperoxide, for example, a mixture of 1,1'-dihydroperoxy-1,1'-dicyclohexyl peroxide and 1,1-dihydroperoxycyclohexane, and a mixture of cyclohexyl And hydroperoxides.

Furthermore, it is preferred to use tertiary hydroperoxides, such as hydroperoxides having at least one hydroperoxy group linked to a tertiary carbon atom. Particularly preferred examples of tertiary hydroperoxides include tert-butyl hydroperoxide (TBHP), tert-amyl hydroperoxide (TAHP), 1,1,3,3-tetramethylbutyl hydroxide (TMBH), 2- Hydroperoxy-2-methyl-3-butene, 2-hydroperoxy-2,4,4-trimethylpentane, 2,5-dihydropperoxy- Dimethylhexane, 2,5-dihydroperoxy-2,5-dimethyl-3-hexane, 2,6-dihydroperoxy-4-hydroxy-2,6-dimethylheptane, Hydroxy-2-methylbutane, 3-ethyl-3-hydroperoxy-2-methylbutane, 2-hydroperoxy- (2-phenyl-2-hydroperoxypropane), m-isopropyl cumyl hydroperoxide, p-isopropyl cumyl hydroperoxide, m- (tert- butylperoxyisobutyl Propyl) cumyl hydroperoxide, p- (tert-butylperoxyisopropyl) cumyl 1-hydroperoxy-1-methylcyclohexane, 1 -hydroperoxy-5-hydroxy-1,3,3-trimethylcyclohexane, p-menthol hydroxide and pyran hydroperoxide. . According to the present invention, a mixture of hydroperoxides may be used as the stabilizer.

Examples of the ethylenically unsaturated organic compound that can not be polymerized singly include dialkyl maleate, dialkyl fumarate,? -Olefin, styrene,? -Methyl styrene,? -Unsaturated ketone represented by the following formula (2) ≪ / RTI > compounds:

In Formula 2, R1 may be selected from the group consisting of hydrogen, alkyl, alkenyl, and aryl, R2 may be selected from the group consisting of hydrogen, alkyl, and aryl, and R3 is selected from the group consisting of hydrogen and alkyl And R4 may be selected from the group consisting of hydrogen, OH and OR5, wherein R5 is selected from the group consisting of alkyl and aryl, and R1 and R3 form a cycloalkenyl or oxa-cycloalkenyl fraction can do.

Wherein R6 and R7, which may be the same or different, are hydrogen, alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 10 carbon atoms, Aralkyl having 7 to 11 carbon atoms, alkenyl having 2 to 6 carbon atoms, bromo, and chloro; Z is -C? N or -C? C-R8 where R8 is hydrogen, alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, alkenyl having 2 to 6 carbon atoms , Aralkyl having 7 to 11 carbon atoms, and aryl having 6 to 10 carbon atoms.

A preferred compound of the ethylenically unsaturated organic compound that can not be monopolymerized is dibutyl maleate (DBM).

The type of the compound having an unstable carbon-hydrogen bond is selected from the group consisting of a? -Dicarbonyl compound and a cyclic? -Diketone compound, and includes diethyl malonate (DEM) and acetylacetone, aliphatic aldehyde and aromatic aldehyde do. Preferred compounds include diethylmalonate (DEM) and acetylacetone.

Also, oxime is selected from the group consisting of compounds represented by the following formula (4).

In Formula 4, R9 and R10 are independently hydrogen, branched or unbranched, substituted or unsubstituted, alkyl having 1 to 22 carbon atoms, alkenyl having 2 to 22 carbon atoms, substituted or unsubstituted Unsubstituted phenyl, or R9 and R10 together with the carbon atoms to which they are attached may form a cycloalkyl ring having from 4 to 8 carbon atoms, substituted or unsubstituted; Or R9 is -C (R11) = N-OH, wherein R11 is hydrogen, branched or unbranched, substituted or unsubstituted alkyl having 1 to 22 carbon atoms or alkenyl having 2 to 22 carbon atoms , Substituted or unsubstituted phenyl, or R < 11 > may be taken together with the carbon atom to which R < 10 > and R < 10 > are attached to form a substituted or unsubstituted cycloalkyl ring having 4 to 8 carbon atoms. Preferred compounds include dibutylglyoxime (DBG) and the like.

According to the method of the present invention described above, a polymerization initiator different in polymerization temperature is added in the step of producing vinyl chloride resin by suspension polymerization, and the amount of the residual initiator is minimized, By controlling the injection amount, it is possible to reduce the whiteness due to the use of the low-efficiency initiator and to solve the problem caused by the incoherent heat of the heat, thereby increasing the production amount. Further, there is no problem of conventional scale generation problems and polymerization degree control.

Hereinafter, the constitution and effects of the present invention will be described in more detail with reference to examples and comparative examples. However, these examples are merely intended to clearly understand the present invention and are not intended to limit the scope of the present invention.

Example  One

All experiments were carried out according to the standard suspension polymerization method.

100 parts by weight of a vinyl chloride monomer, 130 parts by weight of deionized water, 0.04 parts by weight of a polyvinyl dispersant having a degree of saponification of 72% and 0.02 parts by weight of a 55% polyvinyl dispersant were fed into a 1-cubic meter reactor. 0.06 part by weight of 1,1,3,3-tetramethylbutyl peroxyneodecanoate (OND, 1,1,3,3-tetramethylbutyl peroxyneodecanoate) was introduced as an initiator, and the reactor was depressurized and air and nitrogen Respectively.

This was heated to maintain the target polymerization temperature at 65 占 폚, and the temperature was maintained until the pressure dropped. The temperature of the cooling water flowing into the reactor was maintained at 15 ° C. When the temperature of the jacket was lowered to 20 ° C., 0.002 parts by weight of 2,2,6,6-tetramethyl-1-piperidyloxy (TEMPO) Respectively. When the pressure reached 8.7 Kgf / cm < ² >, the reactor was cooled and stopped by adding 0.02 part by weight of Irganox 245 and 0.01 part by weight of sodium hydrogencarbonate as an antioxidant. Unreacted vinyl chloride monomer was recovered through de-vacuuming and the vinyl chloride resin slurry was recovered.

The obtained slurry was washed and dried to obtain a vinyl chloride resin having a polymerization degree of 800.

Example  2

Polymerization was repeated under the same conditions as in Example 1 except that 0.006 parts by weight of the TEMPO injection amount was added to the initiator weight part in Example 1 to obtain a vinyl chloride resin polymer having a polymerization degree of 800. [

Example  3

Polymerization was repeated under the same conditions as in Example 1 except that TEMPO was added at a jacket temperature of 0.5 占 폚 higher than the cooling water temperature flowing into the reactor in Example 1 to obtain a vinyl chloride resin polymer having a polymerization degree of 800. [

Example  4

Polymerization was repeated under the same conditions as in Example 1, except that tert-butyl hydroperoxide (TBHP) was mixed in a ratio of 1: 1 by weight in TEMPO in Example 1 and added in an amount of 0.002 parts by weight based on the initiator weight, A vinyl resin polymer was obtained.

Example  5

Polymerization was repeated under the same conditions as in Example 1, except that 0.06 part by weight of t-butyl peroxyneodecanoate (BND, t-butyl peroxyneodecanoate) was added instead of OND in Example 1, A vinyl resin polymer was obtained.

Example  6: TBHP  Single use

Polymerization was repeated under the same conditions as in Example 1, except that 0.002 parts by weight of TBHP instead of TEMPO was added to the initiator part by weight in Example 1 to obtain a vinyl chloride resin with a polymerization degree of 800. [

Example  7: When using ethylenically unsaturated organic compounds

Polymerization was repeated under the same conditions as in Example 1 except that dibutyl maleate (DBM) was added to the initiator in an amount of 0.002 parts by weight in place of TEMPO in Example 1 to obtain a vinyl chloride resin having a polymerization degree of 800.

Example  8: When using unstable hydrocarbon compound

Polymerization was repeated under the same conditions as in Example 1, except that 0.002 parts by weight of diethylmalonate (DEM) instead of TEMPO was added to the initiator part by weight in Example 1 to obtain a vinyl chloride resin with a polymerization degree of 800. [

Example  9: Oxime  If used

Polymerization was repeated under the same conditions as in Example 1, except that 0.002 parts by weight of dimethyl glyoxime (DMG) was added instead of TEMPO in Example 1 to the initiator weight portion to obtain a vinyl chloride resin polymer having a degree of polymerization of 800. [

Comparative Example  One

A vinyl chloride resin having a polymerization degree of 800 was prepared by repeating the same procedure except that TEMPO was not used as a reaction activity regulator in Example 1 for comparison with the vinyl chloride resin production method of Example 1.

Comparative Example  2

A vinyl chloride resin having a polymerization degree of 800 was prepared by repeating the same procedure as in Example 1 except that 0.04 parts by weight of the amount of TEMPO was added to the initiator in Example 1 to control the reaction.

Comparative Example  3

A vinyl chloride resin having a degree of polymerization of 800 was prepared by repeating the same procedure as in Example 1, except that 0.06 parts by weight of the amount of OND was added to the monomer in Example 1 to control the reaction.

Comparative Example  4

A vinyl chloride resin having a degree of polymerization of 800 was prepared by repeating the same procedure as in Example 1 except that the amount of OND was 0.4 part by weight based on the weight of the monomer.

Comparative Example  5

A vinyl chloride resin having a degree of polymerization of 800 was prepared by repeating the same procedure as in Example 1 except that the injection timing of TEMPO was changed to the jacket temperature of 5.5 캜 higher than the cooling water temperature flowing into the reactor in Example 1.

Comparative Example  6

A vinyl chloride resin having a polymerization degree of 800 was prepared by repeating the same procedure as in Example 1 except that the injection timing of TEMPO was changed to a jacket temperature of 0.1 ° C higher than the cooling water temperature flowing into the reactor in Example 1.

Comparative Example  7: TEMPO Wow Initiator  When starting from the beginning of the reaction

A vinyl chloride resin having a polymerization degree of 800 was prepared by repeating the same procedure as in Example 1 except that the injection timing of TEMPO was changed to the initiator at the beginning of the reaction in Example 1.

The physical properties of the vinyl chloride resin prepared in Example 1-9 and Comparative Example 1-7 were evaluated by the following method.

* Process whiteness measurement :

5 parts by weight of a complex stabilizer (WPS-60, lead stabilizer, Songwon Industry), 1.5 parts by weight of a processing aid (PA-822, acrylic processing aid, LG Chem), 2 parts by weight of titanium oxide And the mixture was roll-milled at 180 ° C for 3 minutes to obtain a sheet having a thickness of 0.5 mm. Then, the whiteness (WI) value was measured using NR-3000 manufactured by Nippon Denshoku Co., Ltd. The results are summarized in Tables 1 and 2. The thermal stability can be measured from the whiteness value. The higher the value, the better the thermal stability.

* Residual initiator  Concentration measurement:

The iodine titration method was used to measure the content of the residual initiator present in the produced vinyl chloride resin. That is, 50 parts by weight of the produced resin and 80 parts by weight of isopropyl alcohol (IPA) were mixed. Then, 20 ml of a 10% acetic acid solution and 20 ml of a 10% potassium iodide solution were added and sufficiently mixed. The amount of iodine produced in the mixed solution was measured by titration using a sodium thiosulfate standard solution until the color disappears. At the same time, a blank test was carried out in the same manner without adding a vinyl chloride resin.

* Measurement of particle size distribution :

The obtained resin was measured for particle size using a HELOS particle size analyzer manufactured by Sumpatec, and the value of the span at that time was defined as a particle size distribution. The lower the value of the span, the smaller the deviation.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Modulator type TEMPO TEMPO TEMPO TEMPO / TBHP
(1: 1) TEMPO TBHP DBM DEM DMG Adjusting agent input amount (parts by weight) 0.002 0.006 0.002 0.002 0.002 0.002 0.002 0.002 0.002 Time of input
(Jacket temperature - coolant temperature) 5.0 5.0 0.5 5.0 5.0 5.0 5.0 5.0 5.0 Initiator type OND OND OND OND BND OND OND OND OND Initiator charge (parts by weight) 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 The number of control agents injected 7 2 7 5 3 4 8 7 6 Particle size distribution 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 Whiteness 72 70 72 74 71 73 71 72 71 Residual initiator concentration (ppm) 8 9 8 6 9 8 7 8 8 Polymerization time (minutes) 242 278 225 229 264 234 241 256 246

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Modulator type - TEMPO TEMPO TEMPO TEMPO TEMPO TEMPO Adjusting agent input amount (parts by weight) - 0.04 0.002 0.002 0.002 0.002 0.002 Time of input
(Jacket temperature - coolant temperature) 5.0 5.0 5.0 5.0 5.5 0.1 - Initiator type OND OND OND OND OND OND OND Initiator charge (parts by weight) 0.06 0.06 0.015 0.4 0.06 0.06 0.06 The number of control agents injected - One 0 10 7 7 5 Particle size distribution 0.62 0.63 0.61 1.3 0.61 1.3 0.62 Whiteness 58 65 68 62 68 62 62 Residual initiator concentration (ppm) 50 26 20 38 21 15 25 Polymerization time (minutes) 173 320 416 171 393 298 352

As can be seen from the results of Tables 1 and 2, it was confirmed that the whiteness and residual initiator concentration of Example 1 using one or more reaction control agents were improved as compared with Comparative Example 1 in which the reaction control agent was not added. Also, as in Examples 1, 4 and 6-9, the reaction modifier minimized the concentration of the residual initiator by controlling the reaction activity irrespective of the kind of the mixture or the modifier, and improved the thermal stability.

In addition, when the addition amount of the reaction activity modifier was higher than 5 캜 as in Comparative Example 5, the reaction time was delayed and the polymerization time became longer. When the thermal limiting limit was lower than 0.5 캜 as in Comparative Example 6, And the particle size distribution was widened.

Therefore, according to the present invention, the concentration of the residual initiator can be minimized by adjusting the timing of introduction of the modifier and the amount of the modifier, and the vinyl chloride resin having high productivity and thermal stability can be efficiently produced through the reaction heat elimination.

Claims (15)

A method for producing a vinyl chloride resin by suspension polymerization while introducing a polymerization initiator, which comprises reacting at least one compound selected from a compound having a free nitroxyl radical, an organic hydroperoxide, an oxime, an ethylenically unsaturated organic compound, and a phenol-based hydrocarbon compound The activity modifier is added in the range of 80 to 99% based on the polymerization temperature limit of the formula (1), the amount of which is 0.033 to 0.1 part by weight based on 1 part by weight of the initiator,
The initiator
(Neodecanoyl peroxy) diisopropylbenzene, cumyl peroxyneodecanoate, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, diisopropyl peroxydicarbonate , 1,1,3,3-tetramethylbutyl peroxyneodecanoate, bis (4-t-butylcyclohexyl) peroxy dicarbonate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, Di-2-ethoxyethyl peroxy dicarbonate, di-2-ethylhexyl peroxy dicarbonate, and 2,2'-azobis (2,4-dimethyl valeronitrile)
Di-n-propyl peroxydicarbonate, diisopropyl peroxy dicarbonate, 1,1,3,3-tetramethyl butyl peroxyneodecanoate, bis (4-t-butyl Cyclohexyl) peroxydicarbonate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, di-2-ethoxyethyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, t- At least one selected from peroxyneodecanoate, dimethoxybutyl peroxy dicarbonate, bis (3-methyl-3-methoxybutyl) peroxy dicarbonate, and t-butyl peroxyneodecanoate, and ,
Di-n-propyl peroxydicarbonate, diisopropyl peroxy dicarbonate, 1,1,3,3-tetramethyl butyl peroxyneodecanoate, bis (4-t-butyl Cyclohexyl) peroxydicarbonate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, di-2-ethoxyethyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, t- Peroxyneodecanoate, dimethoxybutyl peroxydicarbonate, bis (3-methyl-3-methoxybutyl) peroxydicarbonate, t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, Azobisisobutyronitrile, 2,2'-azobis (isobutyronitrile), and dimethyl 2,2'-azobis (isobutyrate).
Process for producing vinyl chloride resin
[Equation 1]

The method according to claim 1,
Wherein the residual concentration of the polymerization initiator in the resin is less than 10 parts by weight relative to 1 million parts by weight of the resin
A method for producing a vinyl chloride resin. The method according to claim 1,
Characterized in that the heat of reaction heat generation by the addition of the activity modifier maintains the heat-releasing limit range of 90 to 99% of the formula (1)
A method for producing a vinyl chloride resin. delete The method according to claim 1,
The compound having a free nitroxyl radical may be 2,2,5,5-tetramethyl-1-pyrrolidinyloxy, 2,2,6,6-tetramethyl-1-piperidyloxy (TEMPO), N- butyl-1-phenyl-2-methylpropyl nitrite, N-tert-butyl-1- (2-naphthyl) -2- methylpropyl nitrite, N-tert- N-tert-butyl-1-dibenzylphosphino-2,2-dimethylpropylnitroxide, N-phenyl-1-diethylphosphono-2,2- Phenylethyl-1-methylethyl nitrite, N- (1-phenyl-2-methylpropyl) -1-diethylphosphono-1-methylethyl nitrite 2-hydroxy-2,2,6,6-tetramethyl-1-piperidyloxy, 4-oxo-2,2,6,6-tetramethyl-1-piperidyloxy, 2, 4,6-tri-tert-butylphenoxy.
A method for producing a vinyl chloride resin. The method according to claim 1,
Examples of the organic hydroperoxide include tert-butyl hydroperoxide (TBHP), tert-amyl hydroperoxide (TAHP), 1,1,3,3-tetramethyl butyl hydroperoxide (TMBH) Methylpentane, 2-hydroperoxy-2-methyl-3-butene, 2-hydroperoxy-2,4,4-trimethylpentane, 2,5-dihydroperoxy- 2,5-dimethyl-3-hexane, 2,6-dihydroperoxy-4-hydroxy-2,6-dimethylheptane, 2-hydroperoxy- 2-methylbutane, 2-hydroperoxy-4-hydroxy-2-methylpentane, 2-hydroperoxy-4-hydroxy- (2-phenyl-2-hydroperoxypropane), m-isopropyl cumyl hydroperoxide, p-isopropyl cumyl hydroperoxide, m- (tert-butylperoxyisopropyl) cumyl Hydroperoxide, p- (tert-butylperoxyisopropyl) cumyl hydroperoxide 1-hydroperoxy-1-methylcyclohexane, 1 -hydroperoxy-5-hydroxy-1,3,3-trimethylcyclohexane, p-menthol hydroxide and pyran hydroperoxide. Featured
A method for producing a vinyl chloride resin. The method according to claim 1,
As the ethylenically unsaturated organic compound, dibutyl maleate (DMB) is used
A method for producing a vinyl chloride resin. The method according to claim 1,
As the phenol-based hydrocarbon compound, diethylmalonate (DEM) or acetylacetone is used
A method for producing a vinyl chloride resin. The method according to claim 1,
And dimethylglyoxime (DMG) is used as the oxime compound
A method for producing a vinyl chloride resin. delete delete The method according to claim 1,
Wherein the initiator is added in an amount of 0.02 to 0.3 parts by weight based on 100 parts by weight of the initial vinyl chloride monomer
A method for producing a vinyl chloride resin. The method according to claim 1,
Characterized in that the polymerization temperature of 55 to 60 DEG C achieves an average degree of polymerization of 1000 products
A method for producing a vinyl chloride resin. The method according to claim 1,
Characterized in that the polymerization temperature of 61 to 65 DEG C achieves an average degree of polymerization of 800 products
A method for producing a vinyl chloride resin. The method according to claim 1,
Characterized in that said polymerization temperature of 66-70 DEG C achieves an average degree of polymerization of 700 products
A method for producing a vinyl chloride resin.