Art
[Mutual citations and related applications;
This application claims the benefit of priority based on party 05.03.2016 Korea Patent Application No. 10-2016-0054645 03.28.2017 and Now Korea Patent Application No. 10-2017-0039347, all described in the literature of the Korea Patent Application content of which is incorporated as a part hereof.
[Technology]
[5]
The present invention is an excellent water sexual characteristics and while maintaining a high conversion rate, it is possible to secure a heat control (除 熱) flow rate, producing a vinyl chloride polymer to improve productivity by enabling the initial reaction, and controlling the reaction end-stage heat value It relates to a process and hence the vinyl chloride polymer prepared in accordance.
[6]
BACKGROUND
[7]
Vinyl chloride-based polymer is a copolymer comprising a homopolymer or vinyl chloride of 50% or more of vinyl chloride, cost-effective and easier to control hardness, a range of applications and is applicable to most of the processing unit. Besides, there are widely used in many fields it is possible to provide a molded article excellent physical and chemical properties, such as mechanical strength, weather resistance, and chemical resistance.
[8]
Usually the case to manufacture a vinyl chloride polymer by suspension polymerization, shows a pattern for increasing the amount of heat generated increases the degree of polymerization during the polymerization the characteristics polymer made of more than 1000 reactions end. This causes the flow rate of the reflux condenser heat removal is maximum at the end. Accordingly, even distribution of heat control flow by advancing to the initial polymerization medium or the heat generation pattern, and to be secured to the end of the flow rate through it.
[9]
Increasing the initial polymerization temperature in the polymerization method for improving end-stage heat removal efficiency in the prior art, the end has a non-isothermal polymerization techniques have been proposed to have a lower reaction activity, while maintaining a degree of polymerization equivalent to the initial. However, for this method to lower the bulk density of the vinyl chloride polymer to be produced, the polymerization conversion falls significantly, a separate equipment is required for the isothermal polymerization effect. In addition, there is a problem in that through the use of the initial activity initiator maximize the initial reaction activity, but this approach to lower the end of heat generation, the Fish eye and the thermal stability is deteriorated, the relative end of the activation reaction time longer apart.
[10]
The development of a method capable of improving the heat removal efficiency in the production of vinyl chloride polymer is required accordingly.
[11]
Detailed Description of the Invention
SUMMARY
[12]
An object of the present invention is to enable the initial reaction, and by controlling the amount of heat generated the end of the reaction it is possible to evenly distribute the heat control flow rate, provides a novel method for producing the resultant vinyl chloride polymer to improve productivity.
[13]
Another object of the present invention is to provide a vinyl chloride resin for producing excellent water contained sexual characteristics vinyl chloride polymer and having a polymerization conversion rate, and this, according to the above method the composition.
[14]
Problem solving means
[15]
In order to solve the above problems, according to one embodiment of the present invention includes a suspension step of polymerizing a vinyl chloride polymer for preparing the monomer in the presence of a polymerization initiator, a dispersant and water-soluble cellulose ether, the dispersing agent has a degree of saponification of the other two comprises a mixture of polyvinyl alcohol or more species, and is also the poly mole average degree of saponification of the vinyl alcohol mixture is 76 mol% to 80 mol%, the water-soluble cellulose ether has a gel point (gel point) is 60 ℃ to 90 ℃, a polymerization initiator provides a process for the production of vinyl chloride-based polymer to be added within or before the polymerization conversion rate of 70%.
[16]
According to another embodiment of the present invention, it is prepared by the above method, and the average particle diameter to 130㎛ 155㎛, an apparent specific gravity to provide a vinyl chloride polymer, from 0.55 to 0.6.
[17]
According to another embodiment of the present invention, there is provided a vinyl chloride resin composition comprising a vinyl chloride polymer prepared by the above method.
[18]
Effects of the Invention
[19]
Method of producing a vinyl chloride polymer according to the present invention can be vinyl-based polymer during manufacture chloride enable the initial reaction, producing a vinyl chloride polymer having excellent water sexual characteristics and high conversion rate by controlling the reaction end of heat generation. In addition, it is possible to evenly distribute the heat control the flow rate in the production of vinyl chloride polymer, and as a result it is possible to greatly improve the productivity.
[20]
Brief Description of the Drawings
[21]
Following figures attached to this specification are intended to illustrate preferred embodiments of the present invention, the components which serve to further understand the teachings of the present invention with the content of the above-described invention, the invention is only to details set forth in those figures is limited shall not be interpreted.
[22]
1 is a graph of observing the heat control pattern in the production of vinyl chloride polymers according to the Comparative Example 1.
[23]
Figure 2 is a graph of observing the heat control pattern in the production of vinyl chloride polymers according to the first embodiment.
[24]
Best Mode for Carrying Out the Invention
[25]
Hereinafter, the present invention will be described in more detail to aid the understanding of the present invention.
[26]
The terms or words used in the specification and claims are general and not be construed as limited to the dictionary meanings are not, the inventor can adequately define terms to describe his own invention in the best way on the basis of the principle that the interpreted based on the meanings and concepts corresponding to technical aspects of the present invention.
[27]
[28]
But in the present invention to use a mixture of modified PVA having a degree specified saponification through modification of the chlorinated polyvinyl alcohol (PVA) is used as a conventional dispersant in the preparation of the vinyl-based polymer chloride by suspension polymerization of two or more, and the average of the mixing PVA by controlling the molar degree of saponification of, it may activate the initial reaction of the vinyl chloride-based polymer production, and when, to lower the amount of heat generated up to the end of the reaction.
[29]
Droplets of vinyl chloride monomer in the initial reaction (droplet) of PVA adsorbed onto the surface by forming an interference wall making apart droplets contact each other and a degree of saponification of the lower the vinyl chloride monomer-water between the surface tension is more robust in low droplet surface it is adsorbed. Thus the As it is easy to swelling between the droplets more aggregation and deformation is to occur, the primary particles within the droplet is subjected to a greater shearing force is in particles agglomerated in the early formation of the open network (open network). Since the place this process is in the early stage of reaction, the polymerization conversion ratio 10%, by charging a mole average degree of saponification of the control PVA mixture within a polymerization conversion of 10% it is possible to activate the reactivity of the initially compared to the previous reactions, than the resulting heat value It can effectively improve the response to gravitate to the end of the heat removing flow uniformity phenomenon. In the conventional heat control pattern due to the lack of reaction end-stage heat control the flow rate of the isothermal or non-isothermal polymerization polymerization can solve the bed volume (volume charge) and the problem that the initiator amount is limited. The batch (batch by production of vinyl polymers chloride in accordance with one embodiment of the present invention may be expanded to all grades (grade) with the largest heat generation pattern to the reaction end, further increase the polymerization initiator to obtain a heat control flow ) it is possible to improve the productivity to maximize sugar yield.
[30]
And that in the present invention, "heat control flow rate" is the temperature rise caused by the exothermic reaction in accordance with the total amount of cooling water introduced in order to control the temperature in the reactor, for example, the polymerization proceeds, the polymerization reactor, using cooling water in order to suppress this, that there is, at this time, the amount of the sum of the cooling water flowing into the upper volume and a reflux condenser, the cooling water flowing into the reactor, the jacket may be a heat removal rate.
[31]
The degree of polymerization of the vinyl chloride polymer is determined by the polymerization temperature, and polymerization degree of the vinyl chloride polymer, it is important to control the polymerization temperature during the polymerization reaction, so factors greatly affecting the physical properties of the product and processing conditions. May be non-car according polymerization polymerization type of initiator, the polymerization method used in, such as the degree of polymerization that uses the presence or absence and the target of the polymerization degree adjusting agent, but the polymerization temperature in the production method of a vinyl polymer chloride in accordance with one embodiment of the present invention 50 ℃ to 65 ℃, it can be more specifically 50 ℃ to 60 ℃. A gel point is a water-soluble cellulose ether when considering the polymerization temperature under the same conditions as the water-soluble cellulose-based polymer when considering the same polymerization temperature is high gel points than the above polymerization temperature, specifically, the cellulose in that the 60 ℃ to 90 ℃ polymerization can be between to prevent gelation non-uniform particle formation or antagonistic form of the person may experience by being deteriorated dispersion stability due to, it is also possible to prevent the high SPAN (particle size distribution) and a large amount of fine particles occurs, which results in a physical property deterioration. Also polyvinyl Because alcohol-based dispersant higher than the dispersion stability big is more influential have on particle stability in the presence or absence of cellulose, act as a dispersing agent by preventing gelling phenomena in the polymerization temperature by the use of having the gelation point as described above cellulose since the can efficiently be increased to a reaction dispersion of initial monomer and initiator it can be further improved the initial reaction activating effect.
[32]
[33]
Specifically, the production process of the vinyl chloride polymer according to one embodiment of the invention, comprising: a suspension step of polymerizing a vinyl chloride-based polymer for making a monomer in the presence of a polymerization initiator, a dispersant and water-soluble cellulose ether, the dispersing agent is the saponification degrees and an average molar degree of saponification of 76 mol% to 80 mol% of the other in a mixture of the poly (vinyl alcohol) mixture, and including at least one kind of polyvinyl alcohol, the water-soluble cellulose ether has a gel point (gel point) to 60 ℃ It said 90 ℃, is added in less than 70% before the start of polymerization or the polymerization conversion rate.
[34]
In the present invention, the polymerization conversion can measure the amount of vinyl chloride monomer to be recovered after the completion of the reaction by the flow meter, and calculating therefrom. The polymerization conversion ratio includes a margin of error of ± 2% during measurement, and the polymerization conversion rate of 0% is meant to include a polymerization starting time or before the start.
[35]
[36]
In the production method of the vinyl chloride polymer, according to an embodiment of the invention, the suspension polymerization solvent and a polymerization initiator, and optionally a protective colloid preparation, such as 1 In the vinyl chloride-based monomer in the at least one additive is charged polymerization reactor by the reaction it can be carried out. At this time, the polymerization and stabilize the reaction product, including the vinyl chloride monomer, a uniform and may be the total volume added to the dispersing agent and the water-soluble cellulose ethers are each polymerized before the start of the polymerization system to act so that the stabilized particle can be produced, or polymerization in the polymerization into the until stopped, specifically, less than 10% of polymerization conversion rate for the dispersant, and may be added in divided or continuous polymerization conversion rate of 70% within the case of the water-soluble cellulose ether.
[37]
[38]
In the production method according to an embodiment of the invention, the dispersing agent is a degree of saponification of the other of two or more, or three or more kinds of polyester comprising a mixture of polyvinyl alcohol, each of the polyvinyl polyester through saponification help mix ratio adjustment of the alcohol It comprises a molar average degree of saponification of the vinyl alcohol mixture is also such that 76% to 80% by mole of the mole of the same. If the molar average saponification degree poly (vinyl alcohol) of the mixture out of the above range, the mouth itself residue (hereinafter referred to as "sieve residue" means) generate a lot and it is difficult to produce uniform particles. If the saponification degree is less than outside the above range 76% by mole, as this lowers the particle stability, and an ellipse or a fear that the generated non-spherical particles such as rod-like, and is intensified uneven upset the particle, the equivalent particle size compared to low It has a bulk density, or there is a fear of lowering processing properties due to wide particle size distribution. Also if the saponification degree exceeds 80 mol%, there is a fear that stable particles is slow increase over the particles inside the pores developed low plasticizer absorptivity too. More specifically, the dispersant may include such that a mixture of two or more kinds of polyvinyl alcohol molar average degree of saponification of 78 mol% to 80 mol% of poly (vinyl alcohol) mixture.
[39]
[40]
In addition, the dispersing agent is under the condition that satisfies the degree molar average degree of saponification of the polyvinyl alcohol mixture and a degree of saponification of more than 40 degrees or more to 60 mol%, 90 mol% or less of the first polyvinyl alcohol, a saponification mol% to 60 mol the second poly (vinyl alcohol) of less than 10%: may be to a weight ratio of 1: 1 to 20. The optimum degree of saponification can be made of a polyvinyl polymer having a greater water sexual characteristics and uniform grain size by including a first and a second polyvinyl alcohol having a degree optimal content. More specifically, the degree of saponification of the second polyvinyl alcohol of at least 40 degrees or more to 60 mol%, 90 mol% or less of the first polyvinyl alcohol, a saponification mol% to less than 60 mol% and 13: in a weight ratio of 1: 1 to 17 It may be included.
[41]
[42]
In addition, the dispersal agent under conditions that molar average degree of saponification of the polyvinyl alcohol mixture is the range and satisfy the first and second conditions of the polyvinyl alcohol at the same time, the first polyvinyl alcohol saponification degree is at least 75 mol% of 90 the mol% or less the polyvinyl 1a 1b the polyvinyl alcohol and of the alcohol, under a degree of saponification of 75 mol% and less than 60 mole% 4: may be to a weight ratio of 1: 1 to 8. The optimum degree of saponification can also be produced polyvinyl chloride polymer having a greater water sexual characteristics and uniform grain size by including a polyvinyl alcohol content of the best of the three having a. More specifically, under the condition that the dispersing agent is the mole average degree of saponification of the range and satisfy the first and second conditions of the polyvinyl alcohol at the same time, the first polyvinyl alcohol to the first 1a of polyvinyl alcohol and the 1b polyvinyl alcohol 4: 1 to 6: there may be a weight ratio of 1.
[43]
[44]
Wherein a dispersing agent may be included as part of 0.05 to 0.15 parts by weight based on 100 parts by weight of vinyl chloride monomer. If less than 0.05 part by weight of the dispersing agent is the particle size of the vinyl chloride polymer it is too increased and the risk occur Fish eye (fish-eye), In excess of 0.15 parts by weight due to the increase of the fine particle there is a risk of early coloring property decreases . Saponification time also to consider that the remarkable for polymerization efficiency and to improve the physical properties of the vinyl chloride polymer effect of the use of a controlled dispersing agent, the dispersing agent may be used as part of 0.05 part by weight to 0.1 parts by weight based on 100 parts by weight of vinyl chloride monomer.
[45]
[46]
The dispersant is if the polymerization before the start may be the total amount added to the polymerization system, or polymerization, but in the after starting may be added by division or continuously until the polymerization terminator, added in excess of the polymerization conversion rate of 10% active early reaction and the reaction end-stage heat control the concentrated flow-preventing effect may be minimal. Accordingly, the dispersing agent may be added within more specifically, before the start of polymerization or the polymerization conversion rate of 10%.
[47]
[48]
Further, in the manufacturing method according to an embodiment of the present invention, the water-soluble cellulose ether is a protective colloid so as to be prepared to stabilize the reaction product of the polymerization and produce a uniform and stable particle. Examples of the water-soluble cellulose ether is methyl cellulose, and the like hydroxyethyl cellulose, or hydroxypropylmethyl cellulose, the one or a mixture of two or more of them may be used.
[49]
[50]
Among the water-soluble cellulose ether it may be one of the gelling point 60 ℃ to 90 ℃. And a water-soluble cellulose fear that if the gelling of ether point below 60 ℃ because of the gelation at the polymerization temperature is lowered efficiency of the dispersant, when it is more than 90 ℃ the bonding between the cellulose occurs, or the hydrophobic group substantially do not exhibit the function as a dispersing agent there is a possibility that can not. In this way, considering also the significantly improved effectiveness of the control according to the gelation point of the water-soluble cellulose ethers, the gelling point of the water-soluble cellulose ether can be 60 ℃ to 90 ℃.
[51]
[52]
The gelation point of the water-soluble cellulose ether is determined by the content of the hydrophobic group such as a methoxy group or hydroxypropyl group bonded to the ends of the polymer. The water-soluble cellulose ether be used in the present invention is within the hydrophobic molecule in the range that meets the above-described gelling point conditions, 20 Specifically, based on the total cellulose content of the hydrophobic group the water-soluble ether by weight comprising a methoxy group and a hydroxypropyl to 40 it may be one of weight%. More specifically, the water-soluble cellulose ether may be while having the content of the above-mentioned hydrophobic group, a methoxy group substitution degree of 10 to 30 wt%, and hydroxypropyl group substitution degree of 6.5 ~ 11.5% by weight. If, when the content of the hydrophobic group exceeds 40% by weight, gelation due to that gelation according to the degradation and the effect as a dispersant it may be reduced, and 20 is less than% by weight of the gelling point excessive increase in cellulose bond formation or hydrophobic group of each other of there is almost no concerns not have a function as a dispersant.
[53]
[54]
The water-soluble cellulose ether may be one of a 2% aqueous solution viscosity at 23 ± 5 ℃ 100 to 250cps. The viscosity of the water-soluble cellulose ether has a dispersibility in the solution phase can be minimal compared to the improvement of the low dose effect when it is more than 250cps.
[55]
[56]
In addition, the water-soluble cellulose ether may be contained from 0.01 to 0.02 parts by weight based on 100 parts by weight of vinyl chloride monomer. If less than 0.01 part by weight of the dispersing agent is the particle size of the vinyl chloride polymer it is too increased and the risk occur Fish eye (fish-eye), In excess of 0.02 because of the increase of the fine particle there is a risk of early coloring property decreases . When the water-soluble cellulose consider that the remarkable efficiency of the polymerization and improved physical properties of the vinyl chloride polymer effect of the use of the ether, the water-soluble cellulose ether may be used from 0.01 to 0.015 parts by weight based on 100 parts by weight of vinyl chloride monomer.
[57]
[58]
The water-soluble cellulose ether is a case to be introduced in excess of the polymerization before the start may be the total amount added to the polymerization system, or the polymerization after the start until the polymerization stops, but may be added by split or continuous, and the polymerization conversion rate of 70% dispersion improving effect it is insufficient, and there is no stabilizing effect of the end of the heating pattern there is a fear that not show any effect as a dispersant. Accordingly, the water-soluble cellulose ethers are more specifically, may be added in less than 70% before the start of polymerization or the polymerization conversion rate, as more specifically may be added at the same time as the dispersing agent in the above-described input time range.
[59]
[60]
Further, in the production method of the vinyl chloride polymer, according to an embodiment of the invention, under conditions that satisfy the above compositional content conditions the dispersing agent and the water-soluble cellulose ether is in the polymerization system is 5: 1: 1 to 10 It can be added to the weight. Out of the above range the content of the input compared to the water-soluble cellulose ether of the dispersant is too high internal pore development is slow it is difficult to raise the plasticizer absorption rate at a certain level or higher, are liable to cause a lot of consequent Fish eye, if too low, contrary particles this stability is lowered there is a risk of non-uniform particle generation. More specifically, the dispersing agent and the water-soluble cellulose ether in the polymerization system is 5: may be added in a weight ratio of 1: 1 to 7.
[61]
[62]
On the other hand, an embodiment wherein the vinyl chloride vinyl chloride-based polymer is a polymer made purely as a vinyl chloride monomer, as well as the vinyl chloride monomer as a main component is copolymerized with the vinyl chloride monomer which is produced by the production method of the polymer according to the embodiment of the present invention It may be a copolymer of a vinyl-based monomer. At this time, when the vinyl chloride-based polymer is a copolymer of vinyl chloride monomer and a vinyl monomer is vinyl chloride in the copolymer it may be one that contains more than 50%.
[63]
Accordingly, the suspension polymerization and the vinyl chloride-based monomer used in the vinyl chloride may be a single material; Or it may be a vinyl chloride, and mixtures of said vinyl chloride copolymer and a vinyl-based monomer. As the vinyl-based monomer is not particularly limited, an ethylene, an unsaturated nitrile, such as propylene, butene, etc. of the olefin (olefin) compounds, acrylonitrile, vinyl acetate and vinyl propionate, vinyl esters such as vinyl stearate, vinyl (vinyl ester) acids, acrylic acids, vinyl methyl ether, vinyl ethyl ether, vinyl octyl ether, vinyl lauryl ether, vinyl alkyl ethers, vinylidene chloride, such as a halogenated vinylidene (vinylidene) acids, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid , maleic anhydride, cross-linked, such as itaconic anhydride, such as unsaturated fatty acids and anhydrides of these acids, methyl acrylate, ethyl acrylate, maleic acid monomethyl maleate, dimethyl maleate, butyl benzyl, etc. of the unsaturated fatty acid ester (ester) acids, diallyl phthalate may be made of monomers such as, any one or a mixture of two or more of them be used There.
[64]
[65]
In addition, the solvent may be a de-ionized water, the amount of the solvent may be appropriately adjusted depending on the amount of monomers used and the polymerization reactor size, for example, relative to 100 parts by weight of vinyl chloride-based monomer used in the suspension polymerization 70 can be used as parts by weight or more.
[66]
[67]
In the polymerization initiator it may be used as part of 0.02 part by weight to 0.2 parts by weight per 100 parts by weight of the vinyl chloride-based monomer used in the polymerization. If, when used in which the polymerization initiator is less than 0.02 parts by weight, it prolongs the polymerization time, and the possibility that the conversion of a vinyl chloride polymer low decrease in productivity, in the polymerization process, when used in excess of 0.2 wt. the polymerization initiator is to remain in the final production of vinyl chloride polymer slurry does not completely consumed in a danger of lowering the thermal stability. More specifically, the polymerization initiator may be used may be 0.04 part to 0.12 part by weight, based on the weight of 100 parts by weight of vinyl chloride monomer.
[68]
The polymerization initiators include specifically, peroxide compounds such as dicumyl peroxide, diphenhydramine tilpeo peroxide, di -3,5,5- trimethyl hexanoyl peroxide or dilauryl peroxide; Diisopropyl peroxydicarbonate, peroxydicarbonate-based compounds, such as di -sec- butyl peroxydicarbonate or di-2-ethylhexyl peroxydicarbonate; t- butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate or t- butyl peroxy neo having peroxy ester compounds such as decanoate; Oh, such as acrylonitrile-azobis-2,4-dimethylvaleronitrile settlement screen cargo; Hydroperoxide oxide sites compounds such as t- butyl hydroperoxide; Or potassium persulfate or the like, and sulfated compounds such as ammonium persulfate, there is any one or a mixture of two or more of them may be used.
[69]
[70]
Further, the suspension polymerization is more specifically 65 to 50 ℃ ℃, can be carried out at a temperature ranging from 50 ℃ to 60 ℃. The polymerization of the vinyl chloride polymer may be a heat removal step through the reactor jacket and a reflux condenser (R / CN) such that the temperature change is kept within 0.1 ℃ range from 0.2 ℃ during the suspension polymerization, since the exothermic reaction carried out .
[71]
When keeping the temperature of a certain level in the polymerization temperature range as described above, be a polymerization reaction, it is possible to prevent the foam generation and suppressing the re-polymerization and scale generated, and the decomposition of the polymerization initiator in the reaction end of the residual sexual derived superior water after reaction characteristics, i.e. that there is a vinyl chloride-based polymer having a degree of polymerization and improved melt processability can be prepared.
[72]
[73]
Also, further added an additive, such as the suspension polymerization is the substrate a protective colloid preparation, as needed in addition to the active ingredient, an antioxidant, a base, a crosslinking agent, a polymerization regulator, a chain transfer agent, pH adjusting agent, an antistatic agent, a scale inhibitor, surfactant, to, and the type and amount of the additives may be used in the industry is known a conventional type, and the sugar content is not particularly limited. The additive may be added at any point in the suspension polymerization of seconds, polymerization during or after the polymerization, may be added at once or added continuously.
[74]
In one example, the protective colloid is prepared to act to stabilize the reaction product of the polymerization and produce a uniform and stable particle may be added at the beginning of the suspension polymerization. The protective colloid preparation may be specifically unsaturated organic acid polymer.
[75]
In the unsaturated organic acid polymer, and specifically, acrylic acid polymer, methacrylic acid polymer, itaconic acid polymer, fumaric acid polymer, maleic acid polymer, succinic acid polymer, or the like, there is one or a mixture of two or more of them may be used.
[76]
[77]
The protective colloid preparation may be added 0.01 parts by weight to 0.02 parts by weight based on 100 parts by weight of a vinyl chloride-based monomer used in the production of vinyl chloride polymer. Protection is colloidal content of the preparation is less than 0.01 parts by weight is that the particle size of the vinyl chloride polymer is too increased and the risk occur Fish eye (fish-eye), addition of 0.02 exceeding parts by weight of the initial coloring property decreases due to the increase of the fine particles there are of concern. Considering that the remarkable the polymerization efficiency and improved physical properties of the vinyl chloride polymer effect of the use of protective colloids to prepare the protective colloid preparation may be added as part of 0.01 part by weight to 0.015 parts by weight per 100 parts by weight of vinyl chloride monomer.
[78]
[79]
In addition, the antioxidant is that which serves to stop the polymerization reaction and a radical of a vinyl chloride polymer, the suspension polymerization end, specifically, based on the equilibrium pressure of the in-flight polymerization polymerization temperature the pressure change 0.5kg / cm 2 to 1.5kg / cm 2 may be added to the point in time. For general preparation of vinyl chloride polymers by suspension polymerization, the earlier point conversion (critical conversion), the while the pressure is maintained constant by maintaining the equilibrium of the liquid and gas phase, after a certain conversion has a vinyl chloride monomer in the gas phase is the equilibrium pressure is broken occurs, the pressure falls as the developing consumption. On the other hand, in the present invention can significantly improve the melt processability of a vinyl chloride polymer by terminating the reaction by the addition of the antioxidant at the time of pressure decrease to a certain level. As a result, it is possible to increase productivity in the manufacture of processed molded article using the same.
[80]
[81]
The antioxidant as long as it is commonly used in the manufacture of vinyl chloride polymers does not especially limited, specific examples include triethylene glycol-bis - [3- (3-t- butyl-5-methyl-4-hydroxyphenyl ) propionate], hydroquinone, p- methoxyphenol, t- butyl hydroxy anisole, n- octadecyl-3- (4-hydroxy-3,5-di -t- butyl) propionate, 2,5-di -t- butyl-hydroquinone, 4,4-butylidenebis (3-methyl -6-t- butylphenol), t- butyl catechol, 4,4-thio-bis (6-t- butyl -m- cresol), phenol compounds, such as tocopherol; N, N- diphenyl -p- amine compounds such as phenylenediamine, 4,4-bis (dimethylbenzyl) diphenylamine; Dodecyl mercaptan, 1,3-and the like sulfur compounds, such as phenyl-2-thiol, there is any one or a mixture of two or more of them may be used.
[82]
[83]
In addition, the antioxidant may be used as part of 0.01 part by weight to 1 part by weight based on 100 parts by weight of a vinyl chloride-based monomer used in the production of vinyl chloride polymer. When When the content of the antioxidant is less than 0.01 parts by weight it is that the particle size of the vinyl chloride polymer is too increased and the risk occur Fish eye, and more than 1 parts by weight due to the increase of the fine particles may cause lowering of the initial coloring. Considering that the remarkable improvement in the polymerization efficiency and the physical properties of the vinyl chloride polymer effect of the use of a protective colloid preparation, the antioxidant may be used as part of 0.05 part by weight to 1 part by weight based on 100 parts by weight of vinyl chloride monomer.
In addition, the base may be a base which is also useful to improve the bulk density of the vinyl chloride-based polymer with a small amount of the protective brought chloride monomer or copolymerizing the monomers miscible with colloid; Or it may be a water-soluble base which acts as an ion in the protective colloid, such as sodium bicarbonate

Claims
[Claim 1]
Includes a suspension step of polymerizing a vinyl chloride-based polymer for making a monomer in the presence of a polymerization initiator, a dispersant and water-soluble cellulose ether, the dispersing agent has a degree of saponification of comprises a mixture of polyvinyl alcohol than the other two species, the polyvinyl alcohol mixture the molar average a degree of saponification of 76 mol% to 80 mol%, the water-soluble cellulose ether is method for producing a vinyl-based polymer chloride to gel point is added within 70% of said 60 ℃ to 90 ℃, polymerization initiation or before the polymerization conversion rate.
[Claim 2]
The method according to claim 1, wherein the dispersing agent is a degree of saponification of the second polyvinyl alcohol of at least 40 degrees or more to 60 mol%, 90 mol% or less of the first polyvinyl alcohol, a saponification mol% to less than 60 mol% of 10: 1 to 20: the method of producing a vinyl chloride polymer comprises a weight ratio of 1.
[Claim 3]
The method according to claim 1, wherein the first poly (vinyl alcohol) is the first polyvinyl alcohol have a saponification degree of less than 75 mol% and 90 mol% or less in claim 1a, a degree of saponification of 75 mol% and less than 60 mol% and polyvinyl alcohol claim 1b polyvinyl alcohol to 4: 1 to 8: the method of producing a vinyl chloride polymer comprises a weight ratio of 1.
[Claim 4]
The method according to claim 1, wherein the dispersing agent is a method for producing a vinyl chloride-based polymer will be an amount of from 0.05 to 0.15 parts by weight based on 100 parts by weight of vinyl chloride monomer.
[Claim 5]
The method according to claim 1, wherein the dispersant is A method for producing a vinyl chloride-based polymer to be added in less than 10% before the polymerization initiator or the polymerization conversion rate.
[Claim 6]
The method according to claim 1, wherein the water-soluble cellulose ether has a content of the hydrophobic group of 20 to 40% by weight of one method of producing a vinyl chloride polymer based on the total weight.
[Claim 7]
The method according to claim 1, wherein the water-soluble cellulose ether is method for producing a vinyl chloride-based polymer to be added to 0.02 parts from 0.01 parts by weight per 100 parts by weight of vinyl chloride monomer.
[Claim 8]
The method according to claim 1, wherein the dispersing agent and the water-soluble cellulose ether is from 5: 1 to 10: the weight ratio The method of producing a vinyl chloride polymer that is added to the first.
[Claim 9]
The method according to claim 1, wherein the polymerization is a method for producing a vinyl chloride-based polymer is performed at 50 ℃ to 65 ℃.
[Claim 10]
The method according to claim 1, based on the polymerization reaction equilibrium pressure at the polymerization temperature of the cabin pressure change 0.5kg / cm 2 to 1.5kg / cm 2 A method for producing a vinyl chloride-based polymer to which an antioxidant is further added at the time.
[Claim 11]
The method according to claim 1, the method for producing a vinyl chloride polymer to initiate polymerization or before the polymerization conversion rate is less than 5% cross-linking agent is further added.
[Claim 12]
The method according to claim 1, a method for producing a vinyl chloride-based polymer to the polyvinyl chloride in an amount of 0.001 to 0.5 parts by weight based on 100 parts by weight of the polymer for manufacture of monomers as a base is further added.
[Claim 13]
Is manufactured by the manufacturing method according to claim 1, wherein an average particle diameter of 130 to 155㎛, a vinyl chloride-based polymer an apparent specific gravity of 0.55 to 0.6.
[Claim 14]
Vinyl chloride-based resin composition comprising a vinyl chloride polymer according to claim 13.
[Claim 15]
The method according to claim 14, to the vinyl chloride-based resin composition that with respect to the vinyl chloride-based polymer comprising 100 parts by weight of a plasticizer, 30 parts by weight to 120 parts by weight.