KR102075566B1 - Vinyl chloride polymer and preparing method thereof - Google Patents

Abstract

The present invention relates to a vinyl chloride-based polymer having improved thermal stability and a method for preparing the same. Accordingly, the vinyl chloride-based polymer contains a certain amount of the boron compound, thereby improving thermal stability, thereby preventing discoloration and deterioration of physical properties due to heat. In addition, the production method through suspension polymerization according to the present invention may contain a certain amount of the boron compound in the vinyl chloride-based polymer prepared without causing deformation to the vinyl chloride-based polymer.
Therefore, the vinyl chloride polymer according to the present invention and a method for preparing the same through suspension polymerization can be easily applied to industries requiring a vinyl chloride polymer, such as vinyl chloride resin and molded article related industries.

Description

Vinyl chloride polymer and its preparation method {Vinyl chloride polymer and preparing method

The present invention relates to a vinyl chloride-based polymer having improved thermal stability and a method for preparing the same.

The vinyl chloride polymer is a polymer containing 50% or more of vinyl chloride, which is inexpensive, easy to control hardness, and can be applied to most processing equipment, thereby increasing its application field. In addition, molded articles having excellent physical and chemical properties such as mechanical strength, weather resistance, chemical resistance, and the like can be provided, and thus they are widely used in various fields.

However, the vinyl chloride-based polymer is dehydrogenated by heat or ultraviolet rays applied during processing due to chemical structural defects generated during the polymerization reaction, thereby causing discoloration of the resin or deteriorating physical properties.

Specifically, in the vinyl chloride polymer, chemical defects generated during the polymerization reaction, that is, chemical structural defects such as allyl chloride or tertiary chlorine are present in the vinyl chloride polymer, and the vinyl chloride polymer is caused by these chemical structural defects. The binding energy of carbon and chlorine is very low compared to the binding energy of carbon and chlorine in the normal molecular structure, so when the vinyl chloride polymer is processed, the bond between carbon and chlorine is easily released due to external radical transition. Hydrogen chloride released from the molecular chain accelerates new side reactions by auto-catalyst reactions, producing hydrogen chloride continuously. In addition, a double bond is formed at the position where the hydrogen chloride has escaped, and due to the overlapping of these double bonds, discoloration of the resin occurs and a problem of deteriorating physical properties occurs. That is, the vinyl chloride polymer or the molded article processed therefrom causes dehydrogenation reactions due to heat or ultraviolet rays, and as a result, discoloration, physical properties, or changes in the vinyl chloride polymer itself occur.

In order to improve the problems of the vinyl chloride-based polymer as described above, radicals generated when the vinyl chloride-based polymer is thermally decomposed by mixing a metal chloride compound containing a metal such as Ba, Zn, Ca, and Pb in the vinyl chloride-based polymer. In order to suppress the generation of or ions and to control the thermal decomposition rate of the resin, various methods of using various types of thermal stabilizers, such as metals or organic compounds, have been introduced. However, environmental problems and high environmental problems caused by heavy metal stabilizers have been introduced. Due to the price is a lot of restrictions on the use of the situation.

In addition, a method of blending a polymer having excellent heat resistance with a vinyl chloride-based polymer has also been proposed to compensate for the weak physical properties, but has been difficult to process due to low miscibility with the vinyl chloride-based polymer.

Therefore, it is necessary to develop a method for improving the thermal stability of the vinyl chloride polymer without causing the above problems.

KR 10-1199094 B1

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide a vinyl chloride polymer having improved thermal stability.

Another object of the present invention is to provide a method for preparing the vinyl chloride-based polymer through suspension polymerization.

In order to solve the above problems, the present invention comprises a boron compound 0.05 parts by weight to 0.2 parts by weight relative to 100 parts by weight of the polymer, the boron compound is sodium borate (Na ₂ B ₄ O ₇ ) and ammonia borane (NH ₃ It provides a vinyl chloride polymer that is at least one of BH ₃ ).

In addition, the present invention comprises the steps of preparing a vinyl chloride-based polymer slurry by suspending the vinyl chloride-based monomer (step 1); And adding and mixing a boron compound to the polymer slurry (step 2), wherein the boron compound is at least one of sodium borate (Na ₂ B ₄ O ₇ ) and ammonia borane (NH ₃ BH ₃ ) It provides a method for producing the vinyl chloride polymer.

The vinyl chloride polymer according to the present invention contains a certain amount of the boron compound, thereby improving thermal stability, thereby preventing discoloration and deterioration of physical properties due to heat.

In addition, the production method through suspension polymerization according to the present invention may contain a certain amount of the boron compound in the vinyl chloride-based polymer prepared without causing deformation to the vinyl chloride-based polymer.

Therefore, the vinyl chloride polymer according to the present invention and a method for preparing the same through suspension polymerization can be easily applied to industries requiring a vinyl chloride polymer, such as vinyl chloride resin and molded article related industries.

The following drawings, which are attached to this specification, illustrate exemplary embodiments of the present invention, and together with the contents of the present invention serve to further understand the technical spirit of the present invention, the present invention is limited to the matters described in the drawings. It should not be construed as limited.
Figure 1 shows the color difference according to the heat treatment of the vinyl chloride polymer of Example 3 and Comparative Example 1 prepared according to an embodiment of the present invention.

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

The terms or words used in this specification and claims should not be construed as being limited to the common or dictionary meanings, and the inventors can appropriately define the concept of terms in order to best explain their invention in the best way possible. It should be interpreted as meanings and concepts corresponding to the technical idea of the present invention based on the principle that the present invention.

The present invention provides a vinyl chloride polymer having excellent thermal stability and low discoloration due to heat and ultraviolet rays.

The vinyl chloride polymer according to an embodiment of the present invention comprises 0.05 parts by weight to 0.2 parts by weight of a boron compound based on 100 parts by weight of the polymer, and the boron compound is sodium borate (Na ₂ B ₄ O ₇ ) and ammonia borane It is characterized by one or more of (NH ₃ BH ₃ ).

The vinyl chloride polymer according to the present invention may include not only a polymer composed of purely vinyl chloride monomer, but also a copolymer of a vinyl chloride monomer and a copolymer with a vinyl monomer copolymerizable with the vinyl chloride monomer. In this case, when the vinyl chloride polymer is a copolymer of a vinyl chloride monomer and a vinyl monomer, 50% or more of vinyl chloride may be included in the copolymer.

The vinyl monomer copolymerizable with the vinyl chloride monomer is not particularly limited, but vinyl esters such as olefin compounds such as ethylene, propylene and butene, vinyl acetate, vinyl propionate and vinyl stearate Unsaturated nitriles such as acrylonitrile, vinyl alkyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl octyl ether and vinyl lauryl ether, vinylidene halides such as vinylidene chloride, acrylic acid and methacryl Unsaturated fatty acids such as acids, itaconic acid, maleic acid, fumaric acid, maleic anhydride, and itaconic anhydride and anhydrides of these fatty acids, unsaturated fatty acid esters such as methyl acrylate, ethyl acrylate, monomethyl maleate, dimethyl maleate, and butylbenzyl maleate And crosslinkable monomers such as diallyl phthalate, and the like. Body may be mixed alone or in combination of two or more.

As described above, the boron compound may be one or more of sodium borate (Na ₂ B ₄ O ₇ ) and ammonia borane (NH ₃ BH ₃ ), and specifically, may be ammonia borane. The boron compound may be included in the vinyl chloride polymer to serve to improve thermal stability. As described above, the vinyl chloride polymer may include 0.05 to 0.2 parts by weight of the boron compound based on 100 parts by weight of the polymer. If the boron compound is contained in less than 0.05 parts by weight, the thermal stability improvement effect of the vinyl chloride polymer may not be good, and if the boron compound is contained in excess of more than 0.2 parts by weight, including the same. In the processing of the vinyl chloride-based polymer may be degraded, the color of the molded article processed therefrom may be reduced.

On the other hand, the vinyl chloride-based polymer according to an embodiment of the present invention may be prepared through suspension polymerization described below. That is, the vinyl chloride polymer may be a suspension polymer, an average particle diameter of 20 μm to 180 μm, and a yellowness of 30 to 58.

Here, the average particle diameter may be measured by using a particle size meter after preparing a sample by diluting the vinyl chloride polymer to 0.1% in deionized water, the yellowness is measured by the method described in Experimental Example to be described later It may be one.

The present invention also provides a method for producing the vinyl chloride polymer.

The production method according to an embodiment of the present invention comprises the steps of preparing a vinyl chloride-based polymer slurry by suspending the vinyl chloride-based monomer (step 1); And adding and mixing a boron compound to the polymer slurry (step 2), wherein the boron compound is at least one of sodium borate (Na ₂ B ₄ O ₇ ) and ammonia borane (NH ₃ BH ₃ ). It is done.

Step 1 is a step for preparing a vinyl chloride-based polymer slurry by polymerizing a vinyl chloride-based monomer, by adding a vinyl chloride-based monomer to a polymerization reactor filled with a solvent, a polymerization initiator and a protective colloid preparation, may be carried out by suspension polymerization. have.

Here, the "filled reactor" may represent a state in which a solvent, a polymerization initiator, and a protective colloid preparation are added to the polymerization reactor before the vinyl chloride monomer is added.

The solvent may be deionized water, and the amount of the solvent may be appropriately adjusted depending on the size of the polymerization reactor and the amount of the monomer to be used. For example, 70 parts by weight based on 100 parts by weight of the vinyl chloride monomer used in the suspension polymerization. It can be used more than a part.

The protective colloid preparation serves to stabilize the reactants during polymerization and to produce uniform and stable particles, and may be used in an amount of 0.03 part by weight to 5 parts by weight based on 100 parts by weight of the vinyl chloride monomer used in the suspension polymerization. have. Specifically, the protective colloid preparation may be used at 0.05 parts by weight to 2.5 parts by weight based on 100 parts by weight of the vinyl chloride monomer. If the protective colloid preparation is used less than 0.03 parts by weight, the size of the particles may be excessively increased so that fish-eye may occur. This may result in the initial decrease in colorability.

The protective colloid preparation may be one or more selected from the group consisting of vinyl alcohol-based resins, celluloses and unsaturated organic acid polymers. Mixtures by weight ratio. In this case, the vinyl alcohol-based resin has a first polyvinyl alcohol having a degree of hydration greater than 50% by weight and 90% by weight or less and a second polyvinyl alcohol having a degree of hydration of 30% by weight to 50% by weight of 2: 1 to 1: 2. It may be a mixture mixed by weight ratio.

In addition, the cellulose includes methyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and the like, and any one or a mixture of two or more thereof may be used. Specifically, the content of the hydroxypropyl group in the molecule may be 3 wt% to 20 wt%, and the viscosity of 2% aqueous solution at 23 ± 5 ° C. may be 10 cps to 20,000 cps.

Examples of the unsaturated organic acid polymers include acrylic acid polymers, methacrylic acid polymers, itaconic acid polymers, fumaric acid polymers, maleic acid polymers, and succinic acid polymers.

The polymerization initiator may be used in an amount of 0.02 part by weight to 0.2 part by weight based on 100 parts by weight of the vinyl chloride monomer used in the polymerization. Specifically, the polymerization initiator may be used from 0.04 parts to 0.12 parts by weight relative to 100 parts by weight of the vinyl chloride monomer. If the polymerization initiator is used in less than 0.02 parts by weight, the polymerization reaction time is long, the conversion rate to the vinyl chloride-based polymer is low, there is a possibility that the productivity is lowered, when used in excess of 0.2 parts by weight polymerization process There is a fear that the polymerization initiator is not completely consumed and remains in the finally prepared vinyl chloride polymer slurry, thereby lowering thermal stability and the like.

The polymerization initiator is not particularly limited, and for example, peroxide-based compounds such as dicumyl peroxide, dipentyl peroxide, di-3,5,5-trimethyl hexanoyl peroxide or dilauryl peroxide; Peroxydicarbonate-based compounds such as diisopropylperoxydicarbonate, di-sec-butylperoxydicarbonate or di-2-ethylhexylperoxydicarbonate; peroxy ester compounds such as t-butylperoxy pivalate, 1,1,3,3-tetramethylbutylperoxy neodecanoate or t-butylperoxy neodecanoate; Azo compounds such as azobis-2,4-dimethylvaleronitrile; hydroperoxide sites such as t-butyl hydroperoxide; Or sulfate-based compounds such as potassium persulfate or ammonium persulfate, and the like, and any one or a mixture of two or more thereof may be used.

The suspension polymerization is not particularly limited, for example, may be carried out in a temperature range of 30 ℃ to 70 ℃, the temperature during the suspension polymerization can be appropriately adjusted according to the degree of polymerization desired within the above range. For example, the higher the degree of polymerization, the lower the temperature, and the lower the degree of polymerization, the higher the temperature.

The suspension polymerization may terminate the polymerization by the addition of a reaction terminator, the termination point is when the pressure in the reactor is 6 kg / cm ² to 8 kg / cm ² (or when the polymerization conversion exceeds 95%) Can be.

The reaction terminator is not particularly limited, but may be, for example, a phenol compound, an amine compound, a nitrile compound, a sulfur compound, or the like. Specifically, the reaction terminator is triethylene glycol-bis-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate, hydroquinone, p-methoxyphenol, t-butylhydro Roxyanisole, n-octadecyl-3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, 2,5-di-t-butyl hydroquinone, 4,4'-part Phenol compounds such as thilidenebis (3-methyl-6-t-butyl phenol), t-butyl catechol, 4,4'-thiobis (6-t-butyl-m-cresol), tocophenol, N, Amine compounds such as N'-diphenyl-p-phenylenediamine, 4,4'-bis (dimethylbenzyl) diphenyl amine, 2-phenyl nitronylnitroxide, 3-imida 3-imidazoline nitroxide, 4-hydroxy-2,2 ', 6,6'-tetramethyl-piperidine-1-oxyl (4-hydroxy-2,2', 6,6 ' nitrile compounds such as -tetramethyl-piperidine-1-oxyl) and sulfur compounds such as dodecyl mercaptan and 1,2-diphenyl-2-thiol. The.

The suspension polymerization may further include additives such as polymerization regulators, chain transfer agents, pH regulators, antioxidants, crosslinking agents, antistatic agents, antiscaling agents, surfactants, etc. The kind and content of the is not particularly limited and can be used as a conventional kind and content known in the art. The additives may be added at any time during the suspension polymerization, during the polymerization or after the polymerization, or may be added in batches or continuously.

Step 2 is a step of preparing a vinyl chloride-based polymer comprising a certain amount of the boron compound by adding and mixing the boron compound to the vinyl chloride polymer slurry prepared by suspension polymerization.

As described above, the boron compound may be one or more of sodium borate (Na ₂ B ₄ O ₇ ) and ammonia borane (NH ₃ BH ₃ ), and specifically, may be ammonia borane.

The boron compound may be used in an amount in which the boron compound is present in an amount of 0.05 parts by weight to 0.2 parts by weight based on 100 parts by weight of the polymer in the finally prepared vinyl chloride polymer.

The manufacturing method according to an embodiment of the present invention may further comprise a step of drying after step 2, the drying is not particularly limited and may be carried out by methods commonly known in the art.

The method for preparing the vinyl chloride polymer according to the present invention may include the boron compound in the vinyl chloride polymer without modifying the vinyl chloride polymer prepared by mixing the boron compound in the vinyl chloride polymer slurry.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the following Examples and Experimental Examples are provided to illustrate the present invention, and the scope of the present invention is not limited only to these examples.

Example 1

390 kg of deionized water was added to a reactor of 1 m ³ internal volume having a reflux condenser, 160 g of polyvinyl alcohol having a degree of hydration of 80%, 120 g of polyvinyl alcohol having a degree of hydration of 45%, hydroxypropylmethyl cellulose 50 g was added to the reactor, 300 kg of vinyl chloride monomer was added, and then 60 g of di-2-ethylhexyl peroxydicarbonate and 150 g of t-butylperoxy neodecanoate were added to initiate the reaction. To achieve an average degree of polymerization of 1000, the reaction temperature was maintained at 57 ° C throughout the course of the polymerization, and 4-hydroxy-2,2,6,6-tetramethyl- when the reactor internal pressure reached 6.3 kg / cm ² . The reaction was terminated by adding 15 g of piperidine-1-oxyl and 90 g of triethylene glycol-bis-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate. Thereafter, the unreacted monomer and the resulting copolymer slurry were separated and recovered, and 60 g of sodium borate was added to the slurry and mixed for 1 hour. After drying in a fluid bed dryer to prepare a vinyl chloride polymer.

Example 2

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that 150 g of sodium borate was used.

Example 3

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that 300 g of sodium borate was used.

Example 4

A vinyl chloride polymer was prepared in the same manner as in Example 3, except that ammonia borane was used instead of sodium borate.

Comparative Example 1

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that sodium borate was not used.

Comparative Example 2

A vinyl chloride polymer was prepared in the same manner as in Example 1, except that 750 g of sodium borate was used.

Experimental Example

In order to analyze the thermal stability of each vinyl chloride polymer prepared in Examples 1 to 4 and Comparative Example 1 and Comparative Example 2, the yellowness of each vinyl chloride polymer was analyzed. The results are shown in Table 1 and FIG.

The yellowness is 50 g of each vinyl chloride-based polymer was pressed at 190 ° C. for 2 minutes to prepare a pan-cake specimen, and color was observed. The lower the value, the better the thermal stability. .

division Thermal stability
(YI) Example 1 57.5 Example 2 50.7 Example 3 35.5 Example 4 42.1 Comparative Example 1 58.4 Comparative Example 2 61.3

As shown in Table 1, the vinyl chloride polymers of Examples 1 to 4 containing the boron compound according to the present invention had better thermal stability than the vinyl chloride polymers of Comparative Examples 1 and 2. In addition, as shown in Figure 1 it was confirmed that the vinyl chloride polymer of Example 4 according to an embodiment of the present invention is significantly whiter than the vinyl chloride polymer of Comparative Example 1.

Specifically, when the vinyl chloride polymer of Examples 1 to 4 including the boron compound according to the present invention and the vinyl chloride polymer of Comparative Example 1 not containing the boron compound were compared, the thermal stability was increased. As the amount of the boron compound increased, the remarkably improved.

On the other hand, in the case of the vinyl chloride polymer of Comparative Example 2 containing the boron compound according to the present invention, but exceeded the highest content range (0.25 parts by weight) presented in the present invention, rather than the vinyl chloride polymer of Comparative Example 1 not included Deteriorated thermal stability was shown.

The above results indicate that not only the boron compound is included but also the amount of the boron compound may significantly affect the thermal stability of the vinyl chloride polymer, and the vinyl chloride polymer according to the present invention contains the boron compound in an appropriate amount. This indicates that the effect of improving thermal stability can be excellent.

Claims (10)

0.05 to 0.2 parts by weight of the boron compound based on 100 parts by weight of the polymer,
The vinyl chloride polymer is the boron compound is ammonia borane (NH ₃ BH ₃ ).
The method according to claim 1,
The polymer is a suspension polymer,
The suspension polymer is a vinyl chloride polymer having an average particle diameter of 20 ㎛ to 180 ㎛, the yellowness of 30 to 58.
1) suspending and polymerizing a vinyl chloride monomer to prepare a vinyl chloride polymer slurry; And
2) adding and mixing a boron compound to the polymer slurry,
The method of producing a vinyl chloride-based polymer of claim 1, wherein the boron compound is ammonia borane (NH ₃ BH ₃ ).
The method according to claim 3,
The boron compound is used in the vinyl chloride polymer prepared in the amount of 0.05 to 0.2 parts by weight based on 100 parts by weight of the polymer.
The method according to claim 3,
The suspension polymerization is a method of producing a vinyl chloride-based polymer that is carried out at a temperature of 40 ℃ to 70 ℃.
The method according to claim 3,
Said suspension polymerization is carried out in a solvent in the presence of a polymerization initiator and a protective colloid preparation.
The method according to claim 6,
The protective colloid preparation is a method of producing a vinyl chloride-based polymer is at least one selected from the group consisting of vinyl alcohol resin, cellulose and unsaturated organic acid polymer.
The method according to claim 6,
The protective colloid preparation is a vinyl chloride-based polymer production method is a mixture of a vinyl alcohol resin and cellulose in a weight ratio of 5: 1 to 7: 7.
The method according to claim 7 or 8,
The vinyl alcohol-based resin has a first polyvinyl alcohol having a degree of hydration greater than 50% by weight and 90% by weight or less and a second polyvinyl alcohol having a degree of hydration of 30% by weight to 50% by weight in a weight ratio of 2: 1 to 1: 2. Method for producing a vinyl chloride polymer is a mixed mixture.
The method according to claim 3,
The manufacturing method is a method of producing a vinyl chloride-based polymer further comprising the step of drying after step 2).

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