KR20210136868A - Method for preparing vinylchloride-based polymer composite, vinylchloride-based polymer composite and vinylchloride-based polymer composite composition comprising the same - Google Patents

Abstract

The present invention relates to a method for preparing a vinyl chloride-based polymer composite, a vinyl chloride-based polymer composite, and a vinyl chloride-based polymer composite composition comprising the same. The method comprises: a first step of bulk polymerization of vinyl chloride-based monomers, and a second step of collecting unreacted vinyl chloride-based monomers and obtaining a vinyl chloride-based polymer composite after the bulk polymerization is completed, wherein polyvinyl alcohol is added in at least one step among the first step and the second step, and the polyvinyl alcohol is added in an amount of 0.003 to 0.500 parts by weight based on 100 parts by weight of the total of the vinyl chloride monomers. According to the present invention, thermal damage of the vinyl chloride-based polymer can be minimized.

Description

Method for producing a vinyl chloride-based polymer composite, a vinyl chloride-based polymer composite, and a vinyl chloride-based polymer composite composition comprising the same

[Citation with related applications]

The present invention claims the benefit of priority based on Korean Patent Application No. 10-2020-0054604 filed on May 07, 2020, and includes all contents disclosed in the documents of the Korean patent application as part of this specification.

[Technology]

The present invention relates to a method for producing a vinyl chloride-based polymer composite, a vinyl chloride-based polymer composite, and a vinyl chloride-based polymer composite composition comprising the same, wherein polyvinyl alcohol is added during or after polymerization to improve thermal stability, color quality and transparency. It is to provide an improved method for producing a vinyl chloride-based polymer composite, a vinyl chloride-based polymer composite, and a vinyl chloride-based polymer composite composition comprising the same.

Vinyl chloride-based polymers are the most widely used synthetic resins among thermoplastic resins. Polymerization methods of the vinyl chloride-based polymer include suspension polymerization, emulsion polymerization and bulk polymerization. Among these, bulk polymerization does not use a solvent, a dispersant, and an emulsifier, but supplies only a vinyl chloride monomer, an initiator, and, if necessary, a reaction additive, and performs polymerization. Polymers polymerized by bulk polymerization are processed and used as raw materials for chlorinated PVC, pipes, chassis, shoe insoles, films, etc., and among them, they are widely used for pipes. The bulk polymerization has advantages in that the device is simple, the reaction is fast, and since it does not go through purification processes such as distillation and extraction, the yield is high, a polymer of high purity can be obtained, and the polymer can be handled as it is.

However, bulk polymerization has a disadvantage in that temperature control is difficult due to strong heat generation during polymerization. In addition, bulk polymerization has a disadvantage in that there is no material that can absorb and remove the heat of polymerization other than the vinyl chloride monomer, and the viscosity of the polymer increases as the polymerization progresses, so that it is difficult to spread the heat of reaction by conduction or convection. Accordingly, in the case of a vinyl chloride-based polymer prepared by bulk polymerization, it is very important to secure the thermal stability of the vinyl chloride-based polymer because it may be damaged due to heat of reaction or unexpected heat generated during bulk polymerization. .

Accordingly, in order to improve the thermal stability during polymerization and/or the thermal stability of the finally prepared vinyl chloride-based polymer/vinyl chloride-based polymer composite, in Chinese Patent Laid-Open No. 107056972, the type of initiator composition in the pre-polymerization step (pre-polymerization step) It is proposed to specify In addition, Korean Patent Application Laid-Open No. 2016-0035439 proposes a manufacturing method in which oxycarboxylic acids, inorganic phosphates, or ethylenediaminetetraacetic acid salts are added during bulk polymerization. In addition, Korean Patent Application Laid-Open No. 2017-0004703 proposes a manufacturing method of copolymerization with a comonomer having excellent heat resistance. However, there is a limit in overcoming the disadvantages of the bulk polymerization method, which is still weak in thermal stability, because the degree of thermal stability improvement is not sufficient by the conventionally proposed method alone.

As such, in preparing a vinyl chloride-based polymer or a vinyl chloride-based polymer composite by a bulk polymerization method, a vinyl chloride-based polymer/vinyl chloride-based polymer composite with significantly improved thermal stability to a level equal to or higher than that of other polymerization methods is prepared. Research on technology is urgently needed.

CN107056972A KR2016-0035439A KR2017-0004703A

An object of the present invention is to provide a method for producing a vinyl chloride-based polymer composite using polyvinyl alcohol that can serve both as a heat stabilizer and an antioxidant.

In addition, it is an object of the present invention to provide a vinyl chloride-based polymer composite and a vinyl chloride-based polymer composite composition having excellent thermal stability, color quality, and transparency.

In order to solve the above problems, the present invention is a first step of bulk polymerization of a vinyl chloride-based monomer; and a second step of recovering unreacted vinyl chloride-based monomers and obtaining a vinyl chloride-based polymer composite after completion of the bulk polymerization, wherein polyvinyl alcohol is added in at least one of the first and second steps, , The polyvinyl alcohol provides a method for producing a vinyl chloride-based polymer composite in which 0.003 parts by weight to 0.500 parts by weight is added based on 100 parts by weight of the total vinyl chloride-based monomer.

In addition, the present invention is a vinyl chloride-based polymer; and polyvinyl alcohol adsorbed to the vinyl chloride-based polymer, wherein the polyvinyl alcohol is included in an amount of 0.003 parts by weight to 0.800 parts by weight based on 100 parts by weight of the vinyl chloride-based polymer. .

In addition, the present invention is the above-mentioned vinyl chloride-based polymer composite; And it provides a vinyl chloride-based polymer composite composition comprising at least one selected from the group consisting of stabilizers, processing aids, impact modifiers and lubricants.

The method for producing the vinyl chloride-based polymer composite of the present invention is a vinyl chloride-based polymer that may be caused by unexpected exotherm in the bulk polymerization process, which is difficult to control temperature by adding polyvinyl alcohol during and/or after the polymerization reaction. It is possible to minimize the thermal damage of the vinyl chloride-based polymer that may occur due to the heat applied during the post-treatment process for the removal of thermal damage and/or unreacted monomers. In addition, the vinyl chloride-based polymer composite prepared by being protected from heat may have excellent thermal stability even when used as a product after manufacturing. In addition, polyvinyl alcohol can suppress the side reaction of the initiator that may occur during the bulk polymerization process. Accordingly, color quality and transparency can be improved by minimizing the coloring of the vinyl chloride-based polymer composite caused by the side reaction.

The vinyl chloride-based polymer composite of the present invention contains polyvinyl alcohol, so that in bulk polymerization that does not use water, it is chlorinated from deformation due to heat generated due to polymerization and from deformation due to heat during a post-treatment process for removing residual unreacted monomers. It is possible to protect the vinyl-based polymer particles, and thus thermal stability, color quality and transparency can all be improved.

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

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

As used herein, the term 'polymer', whether of the same or a different kind, refers to a polymer prepared by polymerizing monomers. The generic term polymer thus encompasses the term homopolymer, which is commonly used to refer to polymers prepared from only one monomer, and the term copolymer prepared from two or more monomers.

The term 'vinyl chloride-based polymer' as used herein encompasses a compound produced by polymerizing a vinyl chloride-based monomer and may mean a polymer chain derived from a vinyl chloride-based monomer.

As used herein, the term 'vinyl chloride-based polymer composite' may be one in which an additive, such as polyvinyl alcohol, is adsorbed to a vinyl chloride-based polymer. Here, the adsorption may include both physical adsorption by van der Waals force and chemical adsorption involving chemical bonding. In addition, in the case of chemical bonding in chemical adsorption, any commonly known chemical bonds such as covalent bonds, ionic bonds, and coordination bonds may be included, for example, a covalent bond between a vinyl chloride-based monomer and a polyvinyl alcohol unit, or a vinyl chloride-based polymer unit and polyvinyl chloride. In addition to covalent bonds between alcohol units, polyvinyl alcohol participates in the polymerization of the vinyl chloride-based polymer, and may mean including polyvinyl alcohol in the main chain of the vinyl chloride-based polymer.

The terms 'first vinyl chloride monomer' and 'second vinyl chloride monomer' used in the present invention are for distinguishing the order in which they participate in the reaction, and the material itself may refer to the same vinyl chloride monomer.

The term 'particle non-uniformity' used in the present invention refers to the surface non-uniformity of the particles or the roughness of the particle surface. It was defined as the average value of , and the smaller the number, the smaller the standard deviation between the diameters of each particle, that is, the diameters of the particles in multiple directions have similar values, indicating that the particle is close to a spherical shape, and thus the roughness of the particle surface is low. Or it could mean smooth.

In the present invention, the number average molecular weight (Mn) is 1.0 using a Breeze GPC (gel permeation chromatography) system from Waters, after diluting 0.02 g of a polymer sample in 20 ml of tetrahydrofuran (THF) solvent and filtering it through a 0.45 μm filter. The molecular weight was measured through a refractive index detector (RI detector) at a flow rate of ml/min. As a standard for calculating the molecular weight of the sample, 8 types of standard PS standards were measured and a calibration curve was prepared, and the molecular weight of the sample was calculated based on this.

The Breeze GPC system consists of an isocratic pump (Waters1515), a refractive index detector (Waters2424), an autosampler (Waters717+), two columns (Waters HR4, HR5), and a Column Heater Chamber. include

In the present invention, the viscosity and polymerization degree of polyvinyl alcohol were measured according to JIS K 6726 (Testing methods for polyvinyl alcohol).

In the present invention, the degree of hydrolysis of polyvinyl alcohol was ^{measured using 1} H 500 MHz NMR. At this time, polyvinyl alcohol was diluted with a solvent of dimethyl sulfoxide (DMSO) to a concentration of 5 wt% (wt/vol), and NMR measurement conditions were as follows.

-Temperature: 60 ℃

- ¹ H NMR standard: tetramethylsilane (TMS)

- Pulse interval: 5 sec

- scan number: 256

1. Method for producing a vinyl chloride-based polymer composite

A method for producing a vinyl chloride-based polymer composite according to an embodiment of the present invention includes a first step of bulk polymerization of a vinyl chloride-based monomer; and a second step of recovering unreacted vinyl chloride-based monomers and obtaining a vinyl chloride-based polymer composite after completion of the bulk polymerization, wherein polyvinyl alcohol is added in at least one of the first and second steps, , The polyvinyl alcohol may be added in an amount of 0.003 parts by weight to 0.500 parts by weight based on 100 parts by weight of the total vinyl chloride monomer.

Here, 100 parts by weight of the total vinyl chloride-based monomer may mean '100 parts by weight of the total content of the vinyl chloride-based monomer input to the method for producing the vinyl chloride-based polymer composite'.

The first step may be performed, for example, in the presence of an initiator. Specifically, the first step includes a pre-polymerization step (step 1-1) of bulk-polymerizing the first vinyl chloride-based monomer to form particle nuclei; and a main polymerization step (step 1-2) of bulk-polymerizing the particle nucleus and the second vinyl chloride-based monomer. For example, the preliminary polymerization step may be to form particle nuclei by bulk-polymerizing the first vinyl chloride-based monomer in the presence of a first initiator, and the present polymerization step is performed in the presence of a second initiator, the particle nuclei and the second It may be bulk polymerization of a vinyl chloride-based monomer. In addition, the present polymerization step may be performed even in a situation in which the second initiator is not present. In this case, the polymerization may be performed by the first initiator remaining in the particle nucleus prepared in the preliminary polymerization step. In addition, in the present polymerization step, in addition to the particle nucleus and the second vinyl chloride monomer, the unreacted first vinyl chloride monomer in the preliminary polymerization step may be polymerized together. For example, the particle nuclei formed after the completion of the preliminary polymerization and the unreacted vinyl chloride-based monomer may be transferred together to the polymerization reactor for bulk polymerization with the second vinyl chloride-based monomer filled in the polymerization reactor. In this case, the second vinyl chloride-based monomer may be added to the main polymerization reactor before, after, or simultaneously with the transfer of the particle nuclei and unreacted monomers in the preliminary polymerization step.

The first and second initiators may be the same as or different from each other, and each independently dicumyl peroxide, dipentyl peroxide, di(3,5,5-trismethylhexanoyl)peroxide diacyl peroxides such as di(3,5,5-trimethylhexanoyl)peroxide and dilauroyl peroxide; Diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, di (2-ethylhexyl) peroxy dicarbonate (di (2-ethylhexyl) peroxydicarbonate), etc. of peroxy carbonates; t-butylperoxy neodecanoate, t-butylperoxy neoheptanoate, t-amyl peroxy neodecanoate, cumyl Peroxyneodecanoate (cumyl peroxy neodecanoate), cumyl peroxy neoheptanoate (cumyl peroxy neoheptanoate), 1,1,3,3-tetramethylbutyl peroxyneodecanoate (1,1,3,3) peroxy esters such as -tetramethylbutyl peroxy neodecanoate); azo compounds such as azobis-2,4-dimethylvaleronitrile; It may be at least one selected from the group consisting of sulfates such as potassium persulfate and ammonium persulfate.

The first or second vinyl chloride monomer may be the same as or different from each other, and each independently may be a pure vinyl chloride monomer, and the pure vinyl chloride monomer as a main component and copolymerizable with the pure vinyl chloride monomer. It may be a mixed monomer comprising a. The mixed monomer may contain 1 to 50 parts by weight of the vinyl-based monomer based on 100 parts by weight of the vinyl chloride monomer. The vinyl-based monomer may be an olefin compound such as ethylene or propylene; vinyl esters such as vinyl acetate and vinyl propionate; unsaturated nitriles such as acrylonitrile; vinyl alkyl ethers such as vinyl methyl ether and vinyl ethyl ether; unsaturated fatty acids such as acrylic acid, methacrylic acid, itaconic acid, and maleic acid; And it may be at least one selected from the group consisting of anhydrides of these fatty acids.

The first initiator may be included in an amount of 0.01 to 0.20 parts by weight, specifically 0.03 to 0.15 parts by weight, and more specifically 0.05 to 0.10 parts by weight, based on 100 parts by weight of the first vinyl chloride-based monomer. When the above-mentioned range is satisfied, the stability of the polymerization process becomes excellent.

The second initiator is 0.03 to 0.60 parts by weight, specifically 0.05 to 0.60 parts by weight, based on 100 parts by weight of the particle nucleus, the unreacted first vinyl chloride monomer and the second vinyl chloride monomer unreacted in the preliminary polymerization step. It may be included in an amount of 0.40 parts by weight, more specifically, 0.08 to 0.30 parts by weight. When the above-mentioned range is satisfied, the stability of the polymerization process becomes excellent.

The bulk polymerization in the prepolymerization step may be carried out at a temperature of 60 °C to 80 °C and a pressure of 9 to 14 kgf/cm2. When the above conditions are satisfied, the particle nucleus may be formed from the first vinyl chloride-based monomer. When the polymerization conversion is 10% to 15%, the first bulk polymerization may be terminated.

The bulk polymerization in the main polymerization step may be performed at a temperature of 50 °C to 70 °C, and a pressure of 7 to 12 kgf/cm2. If the above conditions are satisfied, the particle nuclei may be grown to form a vinyl chloride-based polymer.

Meanwhile, the polyvinyl alcohol may be added in any one of the first step and the second step, and may be added in both the first step and the second step. Specifically, when polyvinyl alcohol is added in the first step, it may be added in at least one of the preliminary polymerization step (step 1-1) and the main polymerization step (step 1-2). In addition, in the preliminary polymerization step, the polyvinyl alcohol may be added before the bulk polymerization is started, and the polyvinyl alcohol may be added during the bulk polymerization. In the main polymerization step, the polyvinyl alcohol may be added before the start of the bulk polymerization, during the block polymerization, or after the block polymerization is completed. More specifically, in the preliminary polymerization step, the polyvinyl alcohol may be added before the bulk polymerization is started, and in the main polymerization step, the polyvinyl alcohol is added before the bulk polymerization is started or after the polymerization is completed, that is, in the second step. Vinyl alcohol may be added. The polyvinyl alcohol may be added while stirring is maintained, and stirring may be performed after the polyvinyl alcohol is added.

In addition, when the polyvinyl alcohol is added in the second step, it may be added after specifically recovering the unreacted vinyl chloride monomer, and more specifically, after recovering the unreacted vinyl chloride monomer after polymerization is completed, It may be added before performing a post-treatment process in order to remove the unreacted vinyl chloride monomer still remaining. In the bulk polymerization process, after separating and recovering unreacted vinyl chloride-based monomers, a post-treatment process of secondary removal of a small amount of unreacted monomers that are not recovered and still remain may be performed. In the separation and recovery process preceding here, any conditions may be applied as long as the conditions are conventionally performed, for example, it may be carried out at room temperature (20±5° C.) vacuum conditions, and the post-treatment process for removing unreacted monomers is heat treatment. may be carried out under vacuum conditions at 70 to 90 ° C., specifically, under pressure conditions of -0.2 kgf/cm 2 to -0.8 kgf/cm 2 . In order to protect the vinyl chloride-based polymer or the vinyl chloride-based polymer composite from heat, the post-treatment process (heat treatment Process) may be to add polyvinyl alcohol before. That is, the second step of the present invention may further include a post-treatment process of heat-treating the vinyl chloride-based polymer composite after recovering the unreacted vinyl chloride-based monomer. In addition, when the polyvinyl alcohol is added in the second step, the polyvinyl alcohol may be added before the post-treatment process is performed after recovering the unreacted vinyl chloride-based monomer.

When the polyvinyl alcohol is added in the above-mentioned step, it is possible to prevent thermal damage to the vinyl chloride-based polymer that may occur due to the heat unexpectedly generated during the bulk polymerization process in which temperature control is difficult. In addition, it is possible to prevent thermal damage to the vinyl chloride-based polymer due to the heat applied in the post-treatment process for removing the unreacted vinyl chloride-based monomer. As such, the vinyl chloride-based polymer prepared by being protected from heat may have excellent thermal stability even when used as a product after manufacturing. In addition, the polyvinyl alcohol may suppress side reactions due to initiators that may occur in each bulk polymerization process in the preliminary polymerization step and the main polymerization step. Due to this, it is possible to minimize the coloration caused by the side reaction, thereby improving the color quality and transparency of the final product, the vinyl chloride-based polymer. In addition, since the processed product using the vinyl chloride polymer is processed at a high temperature, it is very important to secure excellent color quality, transparency and thermal stability. If the polyvinyl alcohol is included in the polymerization process or after polymerization of the vinyl chloride-based polymer, it can be dispersed by reaching the base of the vinyl chloride-based polymer, and both physical and chemical adsorption with the vinyl chloride-based polymer can be achieved. . Accordingly, polyvinyl alcohol is adsorbed to the vinyl chloride polymer according to the manufacturing method of the present invention rather than a processed product manufactured using a composition comprising each component independently by adding a vinyl chloride polymer and polyvinyl alcohol when mixing the composition. Transparency and thermal stability of the processed article using the composition including the polyvinyl chloride-based polymer composite may be much better.

The polyvinyl alcohol is added in an amount of 0.003 to 0.500 parts by weight, specifically 0.005 to 0.500 parts by weight, more specifically 0.200 to 0.500 parts by weight, based on 100 parts by weight of the total of the first and second vinyl chloride monomers. can do. If the above-mentioned range is satisfied, heat damage to the vinyl chloride polymer that may occur due to the heat treatment process for removing the unreacted vinyl chloride monomer and exotherm unexpectedly generated in the bulk polymerization process can be minimized. In addition, since it is possible to suppress side reactions caused by the first and second initiators that may occur during the bulk polymerization process, it is possible to minimize the coloration caused by the side reaction, thereby improving the color quality and transparency of the final product, the vinyl chloride-based polymer. can do it If polyvinyl alcohol is added in an amount of less than 0.003 parts by weight, since it is a small amount that is insufficient to prevent thermal damage to the vinyl chloride-based polymer in the bulk polymerization process and post-treatment process, there is a problem that the effect of improving thermal stability and transparency is hardly exhibited. When polyvinyl alcohol is contained in excess of 0.500 parts by weight, the size of the polyvinyl chloride-based polymer particles is uncontrollably large due to the viscosity of polyvinyl alcohol and the inherent high adsorption property (property to be adsorbed) of polyvinyl alcohol. A phenomenon in which thinning (oversized particle formation) and polymer clump formation (lump phenomenon) may occur frequently. At this time, if the oversize particles in the polymer increase and a lot of lumps are generated due to the lump phenomenon, the yield for obtaining a normal vinyl chloride-based polymer composite is significantly reduced, and the thermal stability and Transparency may be reduced, and a problem in which a large amount of scale is formed in the polymerization reactor may occur. Here, the yield at which a normal vinyl chloride-based polymer composite can be obtained can be confirmed, for example, based on the amount of the vinyl chloride-based polymer composite obtained by filtering through a screen mesh, and the scale of the screen mesh is 30-40 mesh, specifically may be 35 mesh. In the vinyl chloride-based polymer composite according to the present invention, the amount of the vinyl chloride-based polymer composite obtained by filtering through the screen mesh of the scale is about 95% by weight, specifically 95% by weight or more, showing a high yield, but polyvinyl alcohol When an excess is included in excess of 0.500 parts by weight of , there may be a problem in that the yield is significantly lowered to less than about 90% by weight. If the yield is as low as less than 90% by weight, it can be regarded as a level that cannot be used industrially.

In addition, in the present invention, polyvinyl alcohol prevents thermal deformation of the vinyl chloride-based polymer due to heat generated during polymerization of the vinyl chloride-based polymer, and prevents deformation due to heat applied in the post-treatment process for removing unreacted vinyl chloride-based monomers. It is different from polyvinyl alcohol used as a dispersant in the suspension polymerization method of a vinyl chloride-based polymer as an additive serving as a heat stabilizer included to prevent it. Unlike the polyvinyl alcohol of the present invention, which acts as a heat stabilizer to improve the thermal stability and transparency of the prepared vinyl chloride-based polymer composite, polyvinyl alcohol in the suspension polymerization method is added before the polymerization starts or at the beginning of the polymerization to improve the polyvinyl chloride. By helping to form droplets in the reaction mixture containing the monomer-based monomer, it serves to increase the dispersibility of the initial particles of the vinyl chloride-based monomer and the vinyl chloride-based polymer in the polymerization solvent. Accordingly, the formation of coarse polymer particles is prevented by controlling the size and porosity of the prepared polymer particles, particularly the initial polymer particles, thereby preventing deterioration of physical properties such as viscosity and processability of the polymer.

As such, polyvinyl alcohol added in suspension polymerization is added to increase the dispersibility of the initial particles of the vinyl chloride-based monomer and the vinyl chloride-based polymer in the polymerization solvent, and is added in the bulk polymerization method according to an embodiment of the present invention. Since polyvinyl alcohol is added to protect the vinyl chloride polymer from heat applied in the post-treatment process performed after recovery of unreacted monomers and/or exothermic events that are difficult to control during polymerization in the absence of a polymerization solvent, the purpose of addition is different In addition, as described above, since the purpose and effect of the addition are different, the amount of addition used is inevitably different.

In addition, according to an embodiment of the present invention, the polyvinyl alcohol may have a degree of hydrolysis of 30 mol% to 99 mol%, preferably 40 mol% to 99 mol% or 80 mol% to 99 mol% and more preferably 90 mol% to 99 mol% or 95 mol% to 99 mol%. If the degree of hydrolysis of polyvinyl alcohol satisfies the above-mentioned range, in the manufacturing process of the vinyl chloride-based polymer composite, polyvinyl alcohol can lower the rate at which hydrolysis is additionally performed, so the thermal stability and transparency of the prepared vinyl chloride-based polymer composite can be further improved, and in particular, when the degree of hydrolysis is 90 mol% or more, since the degree of hydrolysis of polyvinyl alcohol is already high enough, the hydrolysis rate of polyvinyl alcohol generated during the manufacturing process of the vinyl chloride-based polymer composite can be significantly reduced. and, thereby, thermal stability and transparency may be remarkably improved. When polyvinyl alcohol is hydrolyzed during the polymerization process of the vinyl chloride-based polymer, it becomes difficult to control the size of the vinyl chloride-based polymer particles. There may be problems that reduce stability and transparency.

In the present invention, the degree of hydrolysis of polyvinyl alcohol indicates the degree of hydrolysis, that is, the degree of bonding of hydroxyl groups in the polymer, when the vinyl ester-based polymer is in contact with an alkali substance to form polyvinyl alcohol through hydrolysis. it could be

Polyvinyl alcohol according to an embodiment of the present invention is a linear or branched saturated vinyl ester known in the art, such as vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, and vinyl versatate. It may be obtained from a vinyl ester compound. A mixture of two or more of these vinyl ester compounds or a mixture of vinyl esters and other comonomers may be used. For example, polyvinyl alcohol may be obtained from polyvinyl acetate (polyvinyl acetate) polymerized from a vinyl acetate monomer (VAM) or a monomer mixture including a vinyl acetate monomer. That is, polyvinyl alcohol can be formed by polymerizing or copolymerizing a vinyl ester compound. Polyvinyl alcohol can be formed by partially hydrolyzing the vinyl ester polymer thus obtained. After that, the obtained polyvinyl alcohol can be used as it is in the polymerization process of the present invention, and if necessary, it can be used after treatment with the obtained polyvinyl alcohol to introduce a polyene group (conjugated double bond) into the polymer main chain.

In addition, the vinyl ester polymer obtained by polymerizing or copolymerizing the vinyl ester compound may contain some double bonds derived from the vinyl ester compound (monomer), and these double bonds may be included even after hydrolysis with polyvinyl alcohol. In addition, since the double bond portion becomes a site for reacting with the vinyl chloride-based monomer or the vinyl chloride-based polymer, the polyvinyl alcohol and the vinyl chloride-based monomer or the vinyl chloride-based polymer may form a chemical bond with each other.

The hydrolysis here can be carried out, for example, by contacting the vinyl ester polymer with an alkali substance to carry out transesterification or direct hydrolysis. The hydrolysis temperature may be, for example, in the range of about 10 °C to about 70 °C, such as in the range of about 20 °C to about 50 °C. Alkali materials useful in one embodiment of the present specification include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and lithium hydroxide; and alkali metal alcoholates such as sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide and potassium t-butoxide. For example, saponification may be carried out by bringing the vinyl ester polymer into contact with the alkali substance described above.

In addition, useful solvents for carrying out the hydrolysis include alcohols such as methanol, ethanol, isopropyl alcohol, n-propyl alcohol, n-butanol, isobutanol, sec-butanol, t-butanol, amyl alcohol and cyclohexanol; tetrahydro cyclic ethers such as furan and dioxane; ketones such as acetone, methylethyl ketone, methylisobutyl ketone and pinacorine; sulfoxides such as dimethyl sulfoxide; hydrocarbons such as toluene, benzene, n-hexane and cyclohexane; and mixtures thereof, and a compound capable of swelling or dissolving a vinyl ester polymer and/or polyvinyl alcohol obtained by partial hydrolysis.

After that, the saponified polyvinyl alcohol may be isolated and further processed. For example, the purified polyvinyl alcohol may be recovered by neutralizing the alkali substance remaining in the composition and washing and drying the polymer. The isolation method can be determined by the solubility of the obtained polyvinyl alcohol in a solvent, and poor solvent precipitation, drying, or a combination thereof is mentioned.

According to an embodiment of the present invention, the polyvinyl alcohol may have a viscosity of 3 to 80 pa·s of a 4 wt% aqueous solution at 20 °C, preferably 5 to 70 pa·s, more preferably 6 to It may be 60 pa·s. In addition, the polyvinyl alcohol may have a polymerization degree of 200 to 3,500, preferably 500 to 3,000, more preferably 600 to 2,500. When it has the above-mentioned viscosity range and/or polymerization degree range, the viscosity of polyvinyl alcohol may be a suitable viscosity and polymerization degree to form a vinyl chloride-based polymer composite, so that the dispersibility in the vinyl chloride-based polymer substrate may be further increased, and thus Accordingly, the color quality of the vinyl chloride-based polymer composite can be further improved. In addition, since the pH sensitivity of polyvinyl alcohol participating in the polymerization process and/or post-treatment process is relatively low, the probability of hydrolysis of polyvinyl alcohol during the vinyl chloride-based polymer composite manufacturing process is reduced, so that the heat of the vinyl chloride-based polymer composite Stability can be further improved. In addition, when it has the above-described viscosity range and degree of polymerization, it is possible to further suppress the phenomenon of enlargement of the vinyl chloride-based polymer particles and the formation of lumps of the polymer (lump phenomenon) due to the intrinsic viscosity and adsorption of polyvinyl alcohol. There is an advantage in that the quality such as thermal stability and transparency of the produced vinyl chloride-based polymer is further improved and the formation of scale in the polymerization reactor is suppressed.

In addition, according to an embodiment of the present invention, the polyvinyl alcohol may have a number average molecular weight of 100 to 100,000 g/mol, preferably 500 to 80,000 g/mol, more preferably 1,000 to 50,000 g/mol. . The number average molecular weight may be in a range that can be derived when the viscosity and degree of polymerization of polyvinyl alcohol satisfy the above-mentioned ranges.

In addition, according to an embodiment of the present invention, the vinyl chloride-based polymer included in the vinyl chloride-based polymer composite has a number average molecular weight of 100 to 100,000 g/mol, preferably 500 to 80,000 g/mol, more preferably 1,000 to 50,000 g/mol. In addition, the vinyl chloride-based polymer may have a polymerization degree of 200 to 3,500, preferably 500 to 3,000, more preferably 600 to 2,500.

The polyvinyl alcohol may be added as polyvinyl alcohol in a solid state or may be added as an aqueous solution mixed with an aqueous solvent. For example, polyvinyl alcohol added before the start of bulk polymerization in the preliminary polymerization step or the main polymerization step may be added in a solid state. In the case of adding polyvinyl alcohol in a solid state, it is possible to effectively suppress a problem in which the polymer particles become large during the polymerization process and a phenomenon in which the polymer forms a lump (lump phenomenon). When the polyvinyl alcohol is added in the second step after the polymerization is completed, polyvinyl alcohol having one or more formulations of polyvinyl alcohol in a solid state and polyvinyl alcohol in an aqueous state may be added. In this case, based on the total weight of the aqueous solution, the polyvinyl alcohol may be included in an amount of 1 to 10% by weight, specifically 1 to 7% by weight, and more specifically 3 to 5% by weight. When polyvinyl alcohol is added in an aqueous solution state, if it is added in the above content, the polyvinyl alcohol can be more uniformly dispersed in the vinyl chloride polymer, so that the thermal stability, color quality and Transparency can be further improved. In addition, by stirring after addition of the polyvinyl alcohol, it can be more uniformly dispersed in at least one selected from the group consisting of the first vinyl chloride-based monomer and the second vinyl chloride-based monomer, or a previously prepared vinyl chloride-based polymer. have.

The method for producing a vinyl chloride-based polymer according to the first embodiment of the present invention may include a second step of recovering unreacted vinyl chloride-based monomers after the bulk polymerization is completed and obtaining a vinyl chloride-based polymer composite.

In the second step, when the bulk polymerization conversion reaches 50 to 70%, the bulk polymerization may be completed, and a reaction terminator may be added to complete the bulk polymerization.

The reaction terminator is a material that terminates the reaction by losing the function of the second initiator and/or the first initiator included in the particle nucleus, and is one selected from the group consisting of a phenol compound, an amine compound, a nitrile compound, and a sulfur compound. may be more than one species. The phenolic compound is triethylene glycol-bis-3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate (triethylene glycol-bis-3-(3-t-butyl-4-hydroxy- 5-methylphenyl) propionate), hydroquinone, p-methoxy phenol, t-butyl-4-hydroxyanisole, n-octadecyl- 3-(4-hydroxy-3,5-di-t-butylphenyl)propionate (n-octadecyl-3-(4-hydroxy-3,5-di-t-butylphenyl)propionate), 2,5 -di-t-butyl hydroquinone (2,5-di-t-butyl hydroquione), 4,4'-butylidene bis (3-methyl-6-t-butyl phenol) (4,4'-butylidene bis (3-methyl-t-butyl phenol), t-butyl catechol, 4,4-thiobis (6-t-butyl-m-cresol) (4,4-thiobis (6-t) -butyl-m-cresol), and may be at least one selected from the group consisting of tocopherol.The amine compound is N,N-diphenyl-p-phenylenediamine (N,N-diphenyl-p). -phenylenediamine) and 4,4-bis(dimethylbenzyl)diphenyl (4,4-bis(dimethylbenzyl)diphenyl) may be at least one selected from the group consisting of. The nitrile compound is 4-hydroxy-2,2 ,6,6-tetramethyl-piperidine-1-oxyl (4-Hydroxy-2,2,6,6-tetramethyl piperidine 1-oxyl) The sulfur compound is dodecyl mercaptan And 1,2-biphenyl-2-thiol (1,2-biphenyl-2-thiol) may be at least one selected from the group consisting of.

When the reaction terminator is added, additives such as antioxidants may be added as needed. The antioxidant may be added for the purpose of making the color of the vinyl chloride-based polymer white.

When adding polyvinyl alcohol in the second step, the specific addition timing and amount are the same as described above.

2. Vinyl chloride-based polymer composite

The vinyl chloride-based polymer composite according to an embodiment of the present invention includes a vinyl chloride-based polymer and polyvinyl alcohol adsorbed to the vinyl chloride-based polymer, wherein the polyvinyl alcohol is 0.003 based on 100 parts by weight of the vinyl chloride-based polymer. It is characterized in that it contains 0.800 parts by weight to 0.800 parts by weight.

In addition, the vinyl chloride-based polymer composite of the present invention may be prepared by the above-described method for preparing the vinyl chloride-based polymer composite, and the characteristics of polyvinyl alcohol included in the composite are as described above.

According to an embodiment of the present invention, the polyvinyl alcohol may be included in an amount of 0.003 parts by weight to 0.800 parts by weight based on 100 parts by weight of the vinyl chloride-based polymer, preferably 0.006 parts by weight to 0.600 parts by weight, more preferably may be included in an amount of 0.250 parts by weight to 0.550 parts by weight. The polyvinyl alcohol is hardly lost in the manufacturing process of the vinyl chloride-based polymer composite, and specifically, 80 to 100% of the polyvinyl alcohol added during the manufacturing method of the vinyl chloride-based polymer composite may be included in the polymer. Considering the loss rate of the polyvinyl alcohol and the conversion rate during polymerization of the vinyl chloride-based polymer, polyvinyl alcohol may be included in the above-described range with respect to 100 parts by weight of the total weight of the vinyl chloride-based polymer composite. If the above-mentioned range is satisfied, it is possible to provide a vinyl chloride-based polymer composite excellent in both thermal stability, color quality and transparency without reducing the performance of the vinyl chloride-based polymer composite.

In addition, the vinyl chloride-based polymer composite may have a particle non-uniformity defined by the following formula (1) of 10 or less, preferably 5 or less, more preferably 4 or less.

[Equation 1]

In Equation 1, X _i is the standard deviation of the i-th particle, and is a value defined by Equation 2 below,

[Equation 2]

In Equation 2, A _n is a correction value of the n-th measurement diameter of the i-th particle, wherein the correction value is a value defined by Equation 3 below,

[Equation 3]

In Equation 3, D _n is the n-th measured diameter _{of the i-th particle, D 0} is the longest diameter of the i-th particle, and n is an integer of 1 to 50.

In general, the vinyl chloride-based polymer particles prepared by bulk polymerization have a smooth and angular shape, and the vinyl chloride-based polymer prepared by suspension polymerization has a non-uniform surface. Accordingly, the vinyl chloride-based polymer prepared by suspension polymerization may typically have a particle non-uniformity of greater than 10. As such, the above-mentioned particle non-uniformity in the present invention is a range distinct from the particle non-uniformity of the vinyl chloride-based polymer prepared by suspension polymerization, and the vinyl chloride-based polymer of the vinyl chloride-based polymer composite of the present invention is manufactured by bulk polymerization. It can be confirmed also through the particle non-uniformity that it is a vinyl chloride-based polymer.

3. Vinyl chloride-based polymer composite composition

The vinyl chloride-based polymer composite composition according to an embodiment of the present invention may include one or two or more selected from the group consisting of the vinyl chloride-based polymer composite and a stabilizer, a processing aid, an impact modifier, and a lubricant. In addition, the vinyl chloride-based polymer composite in the vinyl chloride-based polymer composite composition may be a vinyl chloride-based polymer composite prepared according to the above-described method for preparing a vinyl chloride-based polymer composite.

The stabilizer is a material that prevents coloring and decomposition by increasing stability to heat, and may be a metal-based stabilizer or an organic acid metal salt stabilizer. The metal-based stabilizer may be one or two selected from the group consisting of a lead-based stabilizer, an (organic) tin-based stabilizer, a cadmium-based stabilizer, and a barium-based stabilizer. The organic acid metal salt may be a metal salt of carboxylic acid, organic phosphoric acid, or phenols. The carboxylic acid is caproic acid, caprylic acid, pelargonic acid, 2-ethylhexylic acid, capric acid, neodecanoic acid, undecylenic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, 12- Hydroxystearic acid, chlorostearic acid, 12-ketostearic acid, phenyl stearic acid, ricinolic acid, linoleic acid, linolenic acid, oleic acid, arachinic acid, behenic acid, erucic acid, brassic acid, pseudoacid, resin fatty acid, palm oil fatty acid, tung oil fatty acid, 1 selected from the group consisting of soybean oil fatty acid, cottonseed oil fatty acid, benzoic acid, pt-butylbenzoic acid, ethylbenzoic acid, isopropylbenzoic acid, toluic acid, xyllic acid, salicylic acid, 5-t-octylsalicylic acid, naphthenic acid and cyclohexacarboxylic acid species or two or more species. The organic phosphoric acid is monooctyl phosphoric acid, dioctyl phosphoric acid, monododecyl phosphoric acid, didodecyl phosphoric acid, monooctadecyl phosphoric acid, dioctadecyl phosphoric acid, mono(nonylphenyl) phosphoric acid, di(nonylphenyl) phosphoric acid, nonylphenyl phosphonate. It may be one or two or more selected from the group consisting of esters, phosphonate nonylphenyl esters, and phosphonic acid stearyl esters. The phenols may be at least one selected from the group consisting of phenol, cresol, ethylphenol, cyclohexylphenol, nonylphenol, and dodecylphenol. The metal salt may be a neutral salt, an acid salt, a basic salt, or an overbased complex.

The processing aid is a material that promotes the gelation of the vinyl chloride-based polymer, a homopolymer or copolymer of alkyl methacrylate such as methyl methacrylate, ethyl methacrylate, butyl methacrylate; copolymers of the aforementioned alkyl methacrylates and alkyl acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate; copolymers of the above alkyl methacrylates with aromatic vinyl compounds such as styrene, α-methylstyrene and vinyltoluene; and copolymers of alkyl methacrylate and vinyl cyan compounds such as acrylonitrile and methacrylonitrile. The processing aid may be used alone or in a mixture of two or more.

The impact modifier is a material for reinforcing impact resistance by imparting elasticity to the vinyl chloride-based polymer. MBS (Methyl Methacrylate-Butadiene Styrene)-based polymer, chlorinated polyethylene-based copolymer, ethylene vinyl acetate-based polymer, acrylic polymer, and butadiene-based polymer It may be at least one selected from the group consisting of.

The lubricant is a material for improving the processability and interfacial properties of the vinyl chloride-based polymer, and includes hydrocarbon lubricants such as low molecular weight wax, paraffin wax, polyethylene wax, chlorinated hydrocarbon, and fluorocarbon; natural wax-based lubricants such as carnauba wax and candelilla wax; fatty acid-based lubricants such as higher fatty acids such as lauric acid, stearic acid and behenic acid, or oxy fatty acids such as hydroxystearic acid; aliphatic amide compounds such as stearylamide, laurylamide and oleylamide, or aliphatic amide lubricants such as alkylenebisaliphatic amides such as methylenebisstearylamide and ethylenebisstearylamide; Fatty acid monohydric alcohol ester compounds such as stearyl stearate, butyl stearate, and distearyl phthalate, or glycerin tristearate, sorbitan tristearate, pentaerythritol tetrastearate, dipentaerythritol hexastearate, polyglycerin Fatty acid polyhydric alcohol ester compounds such as polyricinolate and hydrogenated castor oil, or fatty acid alcohol esters such as monovalent fatty acids such as adipic acid/stearic acid esters of dipentaerythritol, and complex ester compounds of polybasic organic acids and polyhydric alcohols lubricating agent; aliphatic alcohol lubricants such as stearyl alcohol, lauryl alcohol and palmityl alcohol; metal soaps; montanic acid lubricants such as partially saponified montanic acid esters; acrylic lubricant; and silicone oil. The lubricant may be used alone or in a mixture of two or more.

Hereinafter, preferred embodiments are presented to help the understanding of the present invention, but the embodiments are merely illustrative of the present description, and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope and spirit of the present description, It goes without saying that such variations and modifications fall within the scope of the appended claims.

Example 1

Pre-polymerization reactor of 0.2 m3, main polymerization reactor of 0.5 m3, a reflux condenser connected to the main polymerization reactor to remove heat from the polymerization reaction, and vinyl chloride recovery connected to the reflux condenser and discharging unreacted vinyl chloride monomers A vinyl chloride-based monomer was polymerized in the following manner using a polymerization apparatus including a pipe.

140 kg of vinyl chloride monomer and 85 g of t-butylperoxyneodecanoate were sequentially added to the prepolymerization reactor degassed under high vacuum, and then 11 g of polyvinyl alcohol (hydrolysis degree: 40 mol%) was added and stirred. While maintaining the stirring, the pressure of the pre-polymerization reactor was increased to 12 kgf/cm 2 to perform bulk polymerization to prepare particle nuclei. At this time, the polymerization conversion rate was 10%.

Then, 80 kg of vinyl chloride monomer was put into the main polymerization reactor, the entire amount of particle nuclei prepared in the preliminary polymerization reactor was transferred to the main polymerization reactor, and 1,1,3,3-tetramethyl butyl peroxy neodecano 200 g of ate was added and stirred. While maintaining the agitation, bulk polymerization was carried out at a pressure of 7.5 kgf/cm 2 for 200 minutes. When the polymerization conversion rate reached 60%, 15 g of 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl, triethylene glycol-bis-3-(3-t) -Butyl-4-hydroxy-5-methylphenyl)propionate 100 g was added, and the residual unreacted monomer was recovered by vacuum while stirring was maintained, and the vinyl chloride monomer remaining in the polymer composite was removed even after recovery. After heat treatment at 80 ± 5 ℃ to obtain a vinyl chloride polymer composite.

Examples 2 to 6, Comparative Examples 1 to 3

In Example 1, polyvinyl alcohol (hydrolysis degree: 40 mol%) 11 g instead of polyvinyl alcohol or tetrasodium diphosphate described in Tables 1 and 2 was added in the same manner as in Example 1, except that A vinyl polymer composite was prepared.

Example 7

Pre-polymerization reactor of 0.2 m3, main polymerization reactor of 0.5 m3, a reflux condenser connected to the main polymerization reactor to remove heat from the polymerization reaction, and vinyl chloride recovery connected to the reflux condenser and discharging unreacted vinyl chloride monomers A vinyl chloride-based monomer was polymerized in the following manner using a polymerization apparatus including a pipe.

140 kg of vinyl chloride monomer and 85 g of t-butylperoxyneodecanoate were sequentially added to the prepolymerization reactor degassed under high vacuum, followed by stirring. While maintaining the stirring, the pressure of the pre-polymerization reactor was increased to 12 kgf/cm 2 to perform bulk polymerization to prepare particle nuclei. At this time, the polymerization conversion rate was 10%.

Then, 80 kg of vinyl chloride monomer was put into the main polymerization reactor, the entire amount of particle nuclei prepared in the preliminary polymerization reactor was transferred to the main polymerization reactor, and 1,1,3,3-tetramethyl butyl peroxy neodecano 200 g of ate and 11 g of polyvinyl alcohol (hydrolysis degree: 40 mol%) were sequentially added and stirred. While maintaining the agitation, bulk polymerization was carried out at a pressure of 7.5 kgf/cm 2 for 200 minutes. When the polymerization conversion rate reached 60%, 15 g of 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl, triethylene glycol-bis-3-(3-t) After 100 g of -butyl-4-hydroxy-5-methylphenyl) propionate was added, the residual unreacted monomer was recovered by vacuum while stirring was maintained, and the vinyl chloride monomer remaining in the polymer composite was removed even after recovery. After heat treatment at 80 ± 5 °C to remove, a vinyl chloride polymer composite was obtained.

Examples 8 to 13, Comparative Examples 4 to 6

In Example 7, polyvinyl alcohol (hydrolysis degree: 40 mol%) 11 g of polyvinyl alcohol or tetrasodium diphosphate as shown in Tables 3 and 4 was added instead of 11 g. Chlorinated in the same manner as in Example 7 A vinyl polymer composite was prepared.

Example 14

Pre-polymerization reactor of 0.2 m3, main polymerization reactor of 0.5 m3, a reflux condenser connected to the main polymerization reactor to remove heat from the polymerization reaction, and vinyl chloride recovery connected to the reflux condenser and discharging unreacted vinyl chloride monomers A vinyl chloride-based monomer was polymerized in the following manner using a polymerization apparatus including a pipe.

140 kg of vinyl chloride monomer and 85 g of t-butylperoxyneodecanoate were sequentially added to the prepolymerization reactor degassed under high vacuum, followed by stirring. While maintaining the stirring, the pressure of the pre-polymerization reactor was increased to 12 kgf/cm 2 to perform bulk polymerization to prepare particle nuclei. At this time, the polymerization conversion rate was 10%.

Then, 80 kg of vinyl chloride monomer was put into the main polymerization reactor, the entire amount of particle nuclei prepared in the preliminary polymerization reactor was transferred to the main polymerization reactor, and 1,1,3,3-tetramethyl butyl peroxy neodecano 200 g of ate was added and stirred. While maintaining the agitation, bulk polymerization was carried out at a pressure of 7.5 kgf/cm 2 for 200 minutes. When the polymerization conversion rate reached 60%, 15 g of 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl, triethylene glycol-bis-3-(3-t) -Butyl-4-hydroxy-5-methylphenyl)propionate was added in 100 g, and the residual unreacted monomer was recovered by vacuum while stirring was maintained, and polyvinyl alcohol (hydrolysis degree: 40 mol%) 33 g and stirred. Thereafter, a vinyl chloride polymer composite was obtained after heat treatment at 80±5° C. in order to remove the vinyl chloride monomer remaining in the polymer composite.

Examples 15 to 18, Comparative Examples 7 and 8

In Example 7, polyvinyl alcohol (hydrolysis degree: 40 mol%) 11 g of polyvinyl alcohol or tetrasodium diphosphate described in Tables 5 and 6 was added instead of 11 g. Chlorinated in the same manner as in Example 7 A vinyl polymer composite was prepared.

Comparative Example 9

Pre-polymerization reactor of 0.2 m3, main polymerization reactor of 0.5 m3, a reflux condenser connected to the main polymerization reactor to remove heat from the polymerization reaction, and vinyl chloride recovery connected to the reflux condenser and discharging unreacted vinyl chloride monomers A vinyl chloride-based monomer was polymerized in the following manner using a polymerization apparatus including a pipe.

140 kg of vinyl chloride monomer and 85 g of t-butylperoxyneodecanoate were sequentially added to the prepolymerization reactor degassed under high vacuum, followed by stirring. While maintaining the stirring, the pressure of the pre-polymerization reactor was increased to 12 kgf/cm 2 to perform bulk polymerization to prepare particle nuclei. At this time, the polymerization conversion rate was 10%.

Then, 80 kg of additional vinyl chloride monomer was added to the main polymerization reactor, and the entire amount of particle nuclei prepared in the preliminary polymerization reactor was transferred to the main polymerization reactor, and then 1,1,3,3-tetramethyl butyl peroxyneo 200 g of decanoate was added and stirred. While maintaining the agitation, bulk polymerization was carried out at a pressure of 7.5 kgf/cm 2 for 200 minutes. When the polymerization conversion rate reached 60%, 200 g of butylated hydroxy toluene was added, and then the residual unreacted monomer was recovered in a vacuum while stirring was maintained, and the vinyl chloride remaining in the polymer even after recovery. After heat treatment at 80 ± 5 °C to remove the monomer, a vinyl chloride polymer was obtained.

Comparative Example 10

In Comparative Example 9, a vinyl chloride polymer was prepared in the same manner as in Comparative Example 9, except that di-2-ethylhexyl peroxydicarbonate was added instead of t-butylperoxyneodecanoate to the prepolymerization reactor.

Comparative Example 12

390 kg of deionized water, polyvinyl alcohol aqueous solution (hydrolysis degree: 78.5 mol%, concentration: 4 wt% 3,750 g, polyvinyl alcohol aqueous solution (hydrolysis degree: 40.7 mol%, concentration: 4% by weight) 2,500 g of hydroxypropylmethyl cellulose aqueous solution (concentration: 2% by weight) 1,500 g and 300 kg of vinyl chloride monomer were added, followed by 30 g of di-2-ethylhexylperoxydicarbonate, t-butylperoxyneo After adding 120 g of decanoate, polymerization was carried out while maintaining the polymerization reaction temperature at 57° C. When the polymerization reactor pressure reached 6.3 kgf/cm2, 4-hydroxy-2,2,6,6-tetramethyl -Piperidine-1-oxyl 15 g and triethylene glycol-bis-3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate 60 g were added. was recovered and the resin slurry was recovered in a polymerization reactor, and the obtained slurry was dried in a fluidized bed dryer by a conventional method to obtain a vinyl chloride polymer composite.

Comparative Example 12

90 kg of deionized water, 45 g of hydroxy-dimethylbutyl peroxy ester, 120 g of polyvinyl alcohol (degree of hydrolysis: 80 mol%), 80 g of polyvinyl alcohol (degree of hydrolysis: 40 mol%) in a prepolymerization reactor with an internal volume of 0.2 ㎥ g was added. Thereafter, after vacuum was applied to the pre-polymerization reactor, 75 kg of vinyl chloride monomer was added, the polymerization reaction temperature was raised to 62° C., and polymerization was performed to prepare particle nuclei. At this time, the polymerization conversion was 13%.

360 kg of deionized water, 60 g of cumyl peroxydicarbonate, and 120 g of t-butylperoxy neodecanoate were added to a reactor (main polymerization reactor) having an internal volume of 1 m having a reflux condenser, and polyvinyl alcohol (hydrolysis degree: 80 mol %) 300 g, polyvinyl alcohol (hydrolysis degree: 40 mol %) 250 g, hydroxypropylmethyl cellulose (propyl hydroxide group: 10 wt %, viscosity of 2 wt % aqueous solution measured at 23 ° C: 100 cps) 30 g In addition, after vacuum was applied, 300 kg of vinyl chloride monomer was added.

Then, the obtained particle nuclei and unreacted monomers were added to the polymerization reactor, and the polymerization reaction temperature was adjusted to 57° C., and polymerization was maintained while maintaining the polymerization reaction throughout the entire process. When the polymerization reactor pressure reached 6.5 kgf/cm 2 , 60 g of triethylene glycol-bis-3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate was added, and then unreacted The monomers were recovered and the polymer slurry was withdrawn from the polymerization reactor. The final polymerization conversion was 84%. The obtained slurry was dried in a fluid bed dryer by a conventional method to obtain a vinyl chloride polymer composite.

Experimental Example 1: Measurement of thermal stability

In 100 parts by weight of the vinyl chloride polymer or vinyl chloride polymer composite obtained in Examples and Comparative Examples, 4 parts by weight of mono, dimethyl tin mercaptide complex as a tin-based stabilizer, and acrylic and methyl meta as processing aids Mix 1 part by weight of Acryl and Methyl Methacrylate (MMA) complex, 6 parts by weight of Methyl Methacrylate (MMA) and Butadiene complex as an impact modifier, and roll mill at 185 ° C for 3 minutes. Thus, a preliminary sheet (thickness: 0.5 mm) was prepared. After the preliminary sheet was cut to a predetermined size, a plurality of preliminary sheets were overlapped so that the total weight of the preliminary sheet was 45 g. The overlapping sheets were placed in a mold (thickness: 3 mm) and preheated at 185°C for 2 minutes using a press, low pressure heating for 3 minutes, and high pressure cooling for 2 minutes to prepare a sheet (thickness: 3 mm).

Thereafter, whiteness (W.I) values were measured using a colorimeter NR-3000 (manufactured by Nippon Denshoku), and the results are shown in Tables 1 to 7. Here, the higher the value of the whiteness, the better the thermal stability.

Experimental Example 2: Measurement of resin whiteness and a value

30 g of the vinyl chloride polymer or vinyl chloride polymer composite of each Example and Comparative Example was put into a transparent sample bag, and the surface of the sample bag at the location to be measured was flattened without wrinkles. Whiteness (W.I) values and a values were measured using a colorimeter NR-3000 (manufacturer: Nippon Denshoku), and the results are shown in Tables 3 to 7. The higher the whiteness value, the better the color quality, and the lower the a value, the better the color quality.

Experimental Example 3: Transparency evaluation

In 100 parts by weight of the vinyl chloride polymer or vinyl chloride polymer composite obtained in Examples and Comparative Examples, 2 parts by weight of mono, dimethyl tin mercaptide complex as a tin-based stabilizer, acrylic and 1 part by weight of Acryl and Methyl Methacrylate (MMA) complex, 5 parts by weight of Methyl Methacrylate (MMA) and Butadiene complex as an impact modifier, fatty acid ester and wax complex as lubricant (Fatty acid ester and wax complex) 0.5 parts by weight was mixed, and roll milled at 185° C. for 3 minutes to obtain a preliminary sheet (thickness: 0.5 mm). After the preliminary sheet was cut to a predetermined size, a plurality of preliminary sheets were overlapped so that the total weight of the preliminary sheet was 45 g, and a sheet having a thickness of 6 mm was prepared after compression through press molding. Using the prepared sheet as a sample, turbidity and transmittance were measured using BYK-Gardner (model name: Haze-gard plus), and the results are shown in Tables 1 to 7.

Transmission: It is inversely proportional to the turbidity, and the larger the value, the better the transparency.

Haze: It is defined as the percentage of light that has passed through the sample with respect to the initially emitted beam. The more light passes through the sample, the smaller the value of haze. That is, it means that transparency is excellent, so that the value is small.

Experimental Example 4: Evaluation of particle non-uniformity

The particle non-uniformity is determined by measuring the longest diameter of each particle for a total of 50 particles observed using an optical microscope for each polymer composite or polymer surface, and measuring 50 diameters passing through the center of the following equation 1 to Equation 3 were substituted for calculation. That is, for each 50 particles, using the longest diameter and 50 diameters passing through the center, the diameter standard deviation of each particle is calculated by Equations 2 and 3, and the average of the calculated 50 diameter standard deviations was expressed as the particle non-uniformity.

[Equation 1]

In Equation 1, Xi is the standard deviation of the i-th particle, and is a value defined by Equation 2 below.

[Equation 2]

In Equation 2, A _n is a correction value of the n-th measurement diameter of the i-th particle, where the correction value is a value defined by Equation 3 below.

[Equation 3]

In Equation 3, D _n is the n-th measured diameter _{of the i-th particle, D 0} is the longest diameter of the i-th particle, and n is an integer of 1 to 50.

division Example 1 Example 2 Example 3 Example 4 Example 5 PVA input time prepolymerization prepolymerization prepolymerization prepolymerization prepolymerization Degree of hydrolysis (mol%) 40 80 80 99 99 content g 11 11 110 6.6 22 parts by weight 0.005 0.005 0.050 0.003 0.010 Properties thermal stability 33.1 32.9 36.6 32.4 33.9 Resin Whiteness 90 90 91 89 90 a value 0.8 0.7 0.6 0.9 0.8 Transmittance (%) 85.1 84.9 86.4 84.5 85.2 Turbidity (%) 7.0 7.1 6.6 7.3 7.1 particle non-uniformity 3.58 3.58 3.69 3.67 3.60 PVA: polyvinyl alcohol

division Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 PVA input time prepolymerization prepolymerization prepolymerization - Degree of hydrolysis (mol%) 99 99 99 - content g 1,056 5 1,200 0 parts by weight 0.480 about 0.002 about 0.545 0 TSDP input time - - - prepolymerization content g 0 0 0 220 parts by weight 0 0 0 0.100 Properties thermal stability 40.1 23.9 26.1 25.4 Resin Whiteness 92 86 87 87 a value 0.5 1.2 1.0 1.1 Transmittance (%) 87.3 77.8 76.5 78.7 Turbidity (%) 6.5 10.4 10.7 9.9 particle non-uniformity 3.62 3.55 4.05 3.81 PVA: polyvinyl alcohol
TSDP: Tetrasodium Diphosphate

division Example 7 Example 8 Example 9 Example 10 Example 11 PVA input time Bon polymerization Bon polymerization Bon polymerization Bon polymerization Bon polymerization Degree of hydrolysis (mol%) 40 80 80 99 99 content g 11 110 440 6.6 11 parts by weight 0.005 0.050 0.200 0.003 0.005 Properties thermal stability 33.3 36.5 39.4 32.0 32.8 Resin Whiteness 90 91 92 88 90 a value 0.8 0.5 0.4 1.0 0.5 Transmittance (%) 85.0 86.5 87.3 84.2 84.6 Turbidity (%) 7.0 6.6 6.4 7.4 7.2 particle non-uniformity 3.65 4.12 3.84 3.65 3.61 PVA: polyvinyl alcohol

division Example 12 Example 13 Comparative Example 4 Comparative Example 5 Comparative Example 6 PVA input time Bon polymerization Bon polymerization Bon polymerization Bon polymerization Bon polymerization Degree of hydrolysis (mol%) 99 99 99 99 - content g 22 1,056 4.4 1,200 0 parts by weight 0.010 0.480 0.002 0.545 0 TSDP input time - - - - Bon polymerization content g 0 0 0 0 220 parts by weight 0 0 0 0 0.100 Properties thermal stability 33.8 40.2 24.1 25.8 25.6 Resin Whiteness 90 92 86 87 87 a value 0.6 0.4 1.2 1.0 1.1 Transmittance (%) 85.1 87.6 77.9 76.3 78.9 Turbidity (%) 7.1 6.3 10.3 10.7 9.8 particle non-uniformity 3.63 3.72 3.64 4.11 3.75 PVA: polyvinyl alcohol
TSDP: Tetrasodium Diphosphate

division Example 14 Example 15 Example 16 Example 17 PVA input time after polymerization after polymerization After polymerization After polymerization Degree of hydrolysis (mol%) 40 88 99 99 content g 33 33 6.6 22 parts by weight 0.015 0.015 0.003 0.010 Properties thermal stability 33.6 33.8 32.1 34.0 Resin Whiteness 86 87 89 90 a value 1.3 1.1 0.9 0.7 Transmittance (%) 84.7 84.9 84.1 85.2 Turbidity (%) 7.3 7.2 7.3 7.1 particle non-uniformity 3.74 3.50 3.64 3.62 PVA: polyvinyl alcohol

division Example 18 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 PVA input time after polymerization after polymerization After polymerization - - Degree of hydrolysis (mol%) 99 99 99 - - content g 1,056 4.4 1,200 0 0 parts by weight 0.480 0.002 0.545 0 0 Properties thermal stability 40.1 24.0 26.4 23.7 22.2 resin whiteness 92 86 86 86 85 a value 0.5 1.1 1.1 1.2 1.4 Transmittance (%) 87.5 78.0 75.4 77.6 76.3 Turbidity (%) 6.3 10.3 11.0 10.4 10.8 particle non-uniformity 3.65 3.62 3.60 3.68 3.55 PVA: polyvinyl alcohol

division Comparative Example 11 Comparative Example 12 polymerization method suspension polymerization suspension polymerization PVA input time before polymerization Before the start of the pre-polymerization, before the start of the main polymerization Degree of hydrolysis (mol%) 78.5/40.7 40/80 content g 150/100 300/250 parts by weight 0.05/0.03 0.08/0.07 Properties thermal stability 28.5 27.1 resin whiteness 90 90 a value 0.7 0.7 Transmittance (%) 80.7 79.4 Turbidity (%) 9.3 9.6 particle non-uniformity 15.62 15.13 PVA: polyvinyl alcohol

Referring to Tables 1 and 2, Example 1, in which 0.005 parts by weight of polyvinyl alcohol having a degree of hydrolysis of 40 mol% was added in the preliminary polymerization step, had excellent thermal stability, color characteristics, and transparency. In addition, the degree of hydrolysis was 80 Examples 2 and 3, in which mol% polyvinyl alcohol was added in an amount of 0.005 parts by weight and 0.050 parts by weight, respectively, in the preliminary polymerization step, had excellent thermal stability, color characteristics and transparency.

In addition, Examples 4 to 6, in which 0.003 to 0.480 parts by weight of polyvinyl alcohol having a hydrolysis degree of 99 mol% in the preliminary polymerization step, were excellent in thermal stability, color characteristics, and transparency. However, in Comparative Example 1, in which polyvinyl alcohol having a hydrolysis degree of 99 mol% was added in an amount of about 0.002 parts by weight in the preliminary polymerization step, thermal stability, color characteristics and transparency were lowered compared to Examples 4 to 6. In addition, in Comparative Example 2, in which polyvinyl alcohol having a hydrolysis degree of 99 mol% was added in an amount of about 0.545 parts by weight in the preliminary polymerization step, thermal stability, color characteristics and transparency were lowered compared to Examples 1 to 6.

In Comparative Example 3, in which tetrasodium diphosphate was added in the preliminary polymerization step instead of polyvinyl alcohol, thermal stability, color characteristics and transparency were lowered compared to Examples 1 to 6.

Referring to Tables 3 and 4, Example 7 in which 0.005 parts by weight of polyvinyl alcohol having a degree of hydrolysis of 40 mol% was added in the polymerization step was excellent in thermal stability, color characteristics and transparency.

Examples 8 and 9, in which polyvinyl alcohol having a degree of hydrolysis of 80 mol% was added in an amount of 0.050 parts by weight and 0.200 parts by weight, respectively, in the polymerization step, had excellent thermal stability, color characteristics and transparency.

In addition, Examples 10 to 13, in which 0.003 to 0.480 parts by weight of polyvinyl alcohol having a hydrolysis degree of 99 mol% in the polymerization step, were excellent in thermal stability, color characteristics, and transparency. However, in Comparative Example 4, in which about 0.002 parts by weight of polyvinyl alcohol having a hydrolysis degree of 99 mol% was added in the polymerization step, thermal stability, color characteristics and transparency were lowered compared to Examples 10 to 13. In addition, in Comparative Example 5, in which polyvinyl alcohol having a hydrolysis degree of 99 mol% was added in an amount of about 0.545 parts by weight in the main polymerization step, thermal stability, color characteristics and transparency were lowered compared to Examples 7 to 13.

In Comparative Example 6, in which tetrasodium diphosphate was added in the polymerization step instead of polyvinyl alcohol, thermal stability, color characteristics and transparency were lowered compared to Examples 7 to 13.

Referring to Tables 5 and 6, Example 14, in which 0.015 parts by weight of polyvinyl alcohol having a degree of hydrolysis of 40 mol% was added after the polymerization was completed, had excellent thermal stability, color characteristics and transparency.

Example 15, in which 0.015 parts by weight of polyvinyl alcohol having a degree of hydrolysis of 88 mol% was added after the polymerization was completed, had excellent thermal stability, color characteristics and transparency.

Examples 16 to 18, in which 0.003 parts by weight to 0.480 parts by weight of polyvinyl alcohol having a hydrolysis degree of 99 mol% were added after the polymerization was completed, had excellent thermal stability, color characteristics and transparency. However, in Comparative Example 7, in which polyvinyl alcohol having a hydrolysis degree of 99 mol% was added in an amount of about 0.002 parts by weight after completion of the polymerization, thermal stability, color characteristics and transparency were lowered compared to Examples 16 to 18. In addition, in Comparative Example 8, in which polyvinyl alcohol having a hydrolysis degree of 99 mol% was added in an amount of about 0.545 parts by weight after completion of the polymerization, thermal stability, color characteristics and transparency were lowered compared to Examples 14 to 18.

On the other hand, when polyvinyl alcohol was not added at all and the polymerization conversion reached 60%, 15 g of 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl, triethylene glycol -Bis-3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate 100 g in Comparative Example 9, in which 200 g of butylated hydroxy toluene was added, compared to Examples 1 to 18 Thermal stability, color properties and transparency were deteriorated.

Also, in Comparative Example 9, a vinyl chloride polymer was prepared in the same manner as in Comparative Example 9, except that di-2-ethylhexyl peroxydicarbonate was added instead of t-butylperoxyneodecanoate to the prepolymerization reactor. In Comparative Example 10, compared to Examples 1 to 18, thermal stability, color characteristics, and transparency were lowered.

Comparative Examples 11 and 12, in which the vinyl chloride polymer was prepared by suspension polymerization, had lower thermal stability and transparency compared to Examples 1 to 18.

Claims (13)

A first step of bulk polymerization of a vinyl chloride-based monomer; and
Comprising a second step of recovering unreacted vinyl chloride-based monomers after completion of the bulk polymerization and obtaining a vinyl chloride-based polymer composite,
adding polyvinyl alcohol in at least one step of the first step and the second step,
The polyvinyl alcohol is 0.003 parts by weight to 0.500 parts by weight based on the total 100 parts by weight of the vinyl chloride-based monomer is added to the method for producing a vinyl chloride-based polymer composite.
According to claim 1,
The first step is
A preliminary polymerization step of bulk polymerization of the first vinyl chloride-based monomer to form particle nuclei (step 1-1); and
It comprises the main polymerization step (step 1-2) of bulk polymerization of the particle nucleus and the second vinyl chloride-based monomer,
When the polyvinyl alcohol is added in the first step, the method for producing a vinyl chloride-based polymer composite is added in at least one of the preliminary polymerization step and the main polymerization step.
3. The method of claim 2,
The main polymerization step is a method for producing a vinyl chloride-based polymer composite to bulk-polymerize the particle nuclei, the unreacted first vinyl chloride-based monomer and the second vinyl chloride-based monomer in the preliminary polymerization step.
According to claim 1,
When the polyvinyl alcohol is added in the second step, the method for producing a vinyl chloride-based polymer composite that is added after recovering the unreacted vinyl chloride-based monomer.
According to claim 1,
The second step further comprises a post-treatment process of recovering the unreacted vinyl chloride-based monomer and then heat-treating the vinyl chloride-based polymer composite,
In the case of adding the polyvinyl alcohol in the second step, the method for producing a vinyl chloride-based polymer composite in which unreacted vinyl chloride monomer is recovered and then polyvinyl alcohol is added before performing a post-treatment process.
According to claim 1,
When the polyvinyl alcohol is added in the first step, it is added in a solid state,
When the polyvinyl alcohol is added in the second step, the method for producing a vinyl chloride-based polymer composite that is added in a solid or aqueous solution state.
According to claim 1,
The polyvinyl alcohol is a method for producing a vinyl chloride-based polymer composite having a degree of hydrolysis of 90 mol% to 99 mol%.
According to claim 1,
The polyvinyl alcohol is a method for producing a vinyl chloride-based polymer composite having a viscosity of 3 to 80 pa·s of a 4 wt% aqueous solution at 20 °C.
According to claim 1,
The polyvinyl alcohol is a method for producing a vinyl chloride-based polymer composite having a polymerization degree of 200 to 3,500.
According to claim 1,
The vinyl chloride-based polymer composite is a method for producing a vinyl chloride-based polymer composite in which the polyvinyl alcohol is adsorbed to the vinyl chloride-based polymer.
vinyl chloride-based polymers; and
It contains polyvinyl alcohol adsorbed to the vinyl chloride-based polymer,
The polyvinyl alcohol is a vinyl chloride-based polymer composite comprising 0.003 parts by weight to 0.800 parts by weight based on 100 parts by weight of the vinyl chloride-based polymer.
12. The method of claim 11,
The vinyl chloride-based polymer composite is a vinyl chloride-based polymer composite having a particle non-uniformity of 10 or less as defined according to Equation 1 below.
[Equation 1]

In Equation 1, X _i is the standard deviation of the i-th particle, and is a value defined by Equation 2 below,
[Equation 2]

In Equation 2, A _n is a correction value of the n-th measurement diameter of the i-th particle, wherein the correction value is a value defined by Equation 3 below,
[Equation 3]

In Equation 3, D _n is the n-th measured diameter _{of the i-th particle, D 0} is the longest diameter of the i-th particle, and n is an integer of 1 to 50.
The vinyl chloride-based polymer composite according to claim 11 or 12; and
A vinyl chloride-based polymer composite composition comprising at least one selected from the group consisting of a stabilizer, a processing aid, an impact modifier, and a lubricant.