KR20100042159A - Seed of vinyl chloride with large diameter, method of preparation of the same and vinylchloride resin made by the same - Google Patents

Abstract

PURPOSE: A vinyl chloride-based seed with large diameter is provided to increase an average particle diameter of a resin, to improve properties of plastisol, and to polymerize a vinylchloride resin with excellent polymerization stability. CONSTITUTION: A vinyl chloride-based seed with large diameter has an average particle diameter is 0.65~1.5 micron. A method for preparing the vinyl chloride-based seed with large diameter is prepared by adding a chlorinated vinyl monomer, emulsifier and polymerization initiator to an aqueous medium, homogenizing droplets using a homogenizer pump, and then polymerization. The particle diameter of the seed is controlled by adjusting the homogenizing time.

Description

Seed of vinyl chloride with large diameter, method of preparation of the same and vinylchloride resin made by the same}

The present invention relates to a vinyl chloride-based large-diameter seed for a paste vinyl chloride-based resin, a method for producing the same, and a vinyl chloride-based resin prepared therefrom.

Paste vinyl chloride-based resin is the most widely used general-purpose resin in the world as a living and industrial materials, it is usually produced by emulsion polymerization, fine suspension polymerization, seed emulsion polymerization method.

In the seed emulsion polymerization method, the paste vinyl chloride resin is prepared by injecting seeds having two kinds of average particle diameters different from each other at the initial stage of polymerization, and growing the vinyl chloride monomer while reacting with the seed to produce final latex particles.

Among the two kinds of seeds, the first seed is prepared by adding a vinyl chloride monomer, an emulsifier and a oil-soluble initiator, homogenizing by using a homogenizer pump of a rotor-stator type, and polymerizing it. Currently, an average particle diameter of about 0.54 μm is used. to be. The second seed is prepared by emulsion polymerization and has an average particle diameter of about 0.1 μm. Since the first seed contains the oil-soluble initiator in the particle, the first seed has a reaction site by itself.

In general, during the emulsion polymerization of the vinyl chloride-based resin, a polymerized latex having a particle size in the form of a bimodal having an average particle diameter of about 0.8 to 1.3 μm is obtained. The paste vinyl chloride-based resin prepared by seed emulsion polymerization is used for preparing plastisol, and the viscosity properties of the plastisol tend to depend on the average particle size of the paste-vinyl chloride-based resin.

In the case of using the first seed having an average particle diameter of 0.54 μm, which is conventionally used in the seed emulsion polymerization method, there is a problem in that a resin having a limited particle size cannot be produced without controlling the average particle diameter of the paste vinyl chloride-based resin significantly. . Nevertheless, only the average particle diameter of the first seed was used in the size of 0.54㎛ fixed seed seed polymerization and there was no technology to control the particle size at all. This means that if the average particle diameter of the first seed is increased, it is not the normal polymer but the abnormally occurring polymer masses, which may come out during the polymerization or stick to the reactor wall, which cannot be used in normal products, so filtering in the process More and more, which increases the loss of production and the deterioration of product quality.

However, factors that can control the particle size of the first seed include the amount of emulsifier, the number of revolutions of the homogenizer, the homogenization time of the homogenizer, Agitator rpm, TSC (total solid content), and the like.

Among them, the amount of the emulsifier was changed to adjust the average particle diameter of the vinyl chloride seed used in the seed emulsion polymerization method of the conventional paste vinyl chloride resin. Thus, when the seed emulsion polymerization is carried out using the first seed grown by reducing the amount of the emulsifier, it has a problem that a lot of scale is generated as described above.

In order to solve the problems of the prior art as described above, an object of the present invention is to prepare a large-diameter seed having excellent polymerization stability during seed emulsion polymerization by adjusting the homogenization time of the homogenizer.

By using a large diameter seed having an average particle diameter of 0.54 µm or more prepared from the present invention, a paste vinyl chloride resin having a large average particle size can be produced without increasing scale generation. In addition, the viscosity properties of the plastisol can be improved from this.

Specifically, in the case of using a rotor-stator type homogenizer pump for the polymerization of the seed, the average particle size of the seed is to be manufactured to be larger than 0.54 μm.

The above and other objects of the present invention can be achieved by the present invention described below.

The present invention provides a method for producing a vinyl chloride-based large-diameter seed by adding a vinyl chloride monomer, an emulsifier, and a polymerization initiator to an aqueous medium and homogenizing droplets using a homogenizer pump to adjust the seed particle size by adjusting the homogenization time. It provides a method for producing a vinyl chloride-based large diameter seed, characterized in that the adjustment.

Preferably, the homogenization may be performed for 1 hour to 3 hours.

The homogenizer pump may be of rotor-stator type.

The present invention provides a vinyl chloride-based large diameter seed, characterized in that produced by the above production method.

In addition, the present invention provides a paste-vinyl chloride-based resin, which is prepared by seed emulsion polymerization using the vinyl chloride-based large-diameter seed as the first seed.

The vinyl chloride resin has an average particle diameter of 0.8 ~ 3.0㎛.

According to the method for preparing a vinyl chloride-based large diameter seed of the present invention, a seed having an average particle diameter of 0.54 μm or more may be manufactured using a homogenizer pump of a rotor-stator type. In addition, when this was applied to the seed emulsion polymerization of the vinyl chloride-based resin, it was possible to prepare a paste-vinyl chloride-based resin having excellent polymerization stability without increasing scale generation.

The present invention provides a stable vinyl chloride large-diameter seed latex having an average particle diameter of 0.65 to 1.5 µm by adding a vinyl chloride monomer, an emulsifier, and a polymerization initiator to an aqueous medium, homogenizing the droplets using a homogenizer pump, and then polymerizing.

The present invention is characterized by controlling the circulation time in the homogenizer in order to control the average particle diameter during the preparation of large diameter seeds.

When the large-diameter seed is applied to the seed emulsion polymerization method of the paste vinyl chloride-based resin, it is possible to prepare a paste-vinyl chloride-based resin having an increased average particle diameter without increasing generation of scale. In addition, the use of such a resin can improve the viscosity properties of the plastisol.

In the seed emulsion polymerization method of the paste vinyl chloride resin, the vinyl chloride monomer is polymerized by adding an emulsifier, a first seed, a second seed, a buffer, a redox catalyst and the like in an aqueous medium. The vinyl chloride monomer used in the paste vinyl chloride resin polymerization is generally 80 to 98 wt% of the paste vinyl chloride resin and the remaining unreacted monomer is removed. The latex of the paste vinyl chloride resin after polymerization is obtained by spray drying. In drying, dehydration filtration or the like is not generally performed. Thus, raw materials such as an emulsifier remain in the resin. The paste vinyl chloride resin having a particle size of 0.1 to 50 µm basically has good dispersibility of the plasticizer and is suitable for paste processing.

As the emulsifier, anionic emulsifiers or nonionic emulsifiers may be used alone or in combination of two or more thereof.

As the anionic emulsifier, carboxylic acid, alkyl sulfonic acid, alkyl benzene sulfonic acid, sulfo succinic acid, α-olefin sulfonic acid, or alkyl phosphoric acid may be used. The anionic emulsifier may be used up to 1 part by weight based on 100 parts by weight of the vinyl chloride monomer. When used in the above content has excellent effects such as mechanical stability of the polymerization and latex.

Examples of the nonionic emulsifier include polyoxyethylene ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkenyl ether, polyoxyethylene derivative, glycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene fatty acid ester, silicone emulsifier, polyethylene Glycol (polyethylene-glycol) and derivatives thereof, or polypropylene glycol (polyepropylene-glycol) and derivatives thereof may be used. The nonionic emulsifier is not particularly limited in content, and may be used in an amount of up to 3 parts by weight based on 100 parts by weight of the vinyl chloride monomer.

The emulsifier may be added in an aqueous medium before the seed emulsion polymerization reaction, may be continuously added to the aqueous medium during the polymerization reaction, may be added to the latex after completion of the polymerization reaction may be used in combination with the above method if necessary. .

The first seed may be prepared by microsuspension polymerization. That is, it is obtained by adding a vinyl chloride monomer, an emulsifier, and a polymerization initiator to the aqueous medium, homogenizing the droplets using a homogenizer pump and then polymerizing.

Polymerization initiators used herein include oil-soluble polymerization initiators such as peroxy dicarbonates such as diisopropyl peroxy dicarbonate; organic peroxide initiators such as peroxy esters such as t-butyl peroxy pivalate and t-butyl peroxy neodecanoate, or azo (azo) such as 2,2-azobisisobutyronitrile. ) Initiator or the like can be used alone or in combination. As a polymerization initiator, 1-2 weight part is used normally with respect to 100 weight part of vinyl chloride monomers.

In the preparation of the first seed, an auxiliary dispersant may be used together with the emulsifier to maintain polymerization and stability of the seed latex. Specifically, higher alcohols such as lauryl alcohol, mystic alcohol, stearyl alcohol, or higher fatty acids such as lauric acid, myristic acid, partic acid, stearic acid, and the like can be used.

The above components may be added to an aqueous medium to homogenize the droplets using a rotor-stator type homogenizer pump, and then polymerized to prepare a vinyl chloride-based seed.

The present invention shortened the homogenization time in the homogenizer in the polymerization process to increase the average particle diameter of the seed 40 to 60% compared with the conventional.

Homogenization time depends on the reaction scale, but the homogenization time is currently averaged about 4 hours in the production of vinyl chloride seed. Therefore, the homogenization time suggested by the present invention is substantially 1 to 3 hours.

When the vinyl chloride seed is prepared by the above method, a vinyl chloride large diameter seed having an average particle diameter of 0.65 to 1.5 µm can be prepared. In addition, when applied to the seed emulsion polymerization, it is possible to produce a paste vinyl chloride resin having an average particle size of 0.8 ~ 3.0㎛ excellent polymerization stability without increasing the scale generation.

Hereinafter, preferred examples are provided to help the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it is apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. And modifications fall within the scope of the appended claims.

 Example 1

First seed polymerization

While stirring the Agitator at 40 rpm in a 200 L high-pressure reactor, 97 kg of deionized water, 89 g of KH ₂ PO ₄ , 11 g of NaOH (98%), 1.2 kg of Laruyl peroxide, and 0.9 g of Paraquinone were put in a vacuum at -730 mmHg. . 66 kg of vinyl chloride monomer and 7.8 kg of sodium dodecyl benzene sulfonate (15%) were added to the reactor under vacuum, followed by stirring for 15 minutes. The internal temperature of the reactor was lowered below 20 ° C., and homogenization was performed for 2 hours using a rotor-stator type homogenizer. Upon completion of homogenization, the reactor temperature was adjusted to 43 ° C. and polymerization was carried out. When the reactor pressure reached 3.5 kg / cm 2, the reaction was terminated. After the unreacted vinyl chloride monomer was recovered and removed, the average particle diameter was 0.77 μm, TSC (total solid content) was 35%, and the lauryl peroxide content was 1.77. % First seed latex was obtained.

Seed emulsion polymerization for flooring (paste vinyl chloride resin)

In a 200 L high pressure reactor, 46 kg of deionized water, 77 kg of vinyl chloride monomer, 4.3 kg of sodium dodecyl benzene sulfonate (15%), and the temperature of the high pressure reactor were heated to 51.5 ° C. to prepare an emulsion of vinyl chloride latex for 7 hours. The used first seed had an average particle diameter of 0.77 μm, TSC (total solid content) of 35%, a soluble initiator (Lauryl peroxide) content of 1.77% and 9 kg. The second seed had an average particle diameter of 0.1 μm, TSC (total solid content) of 40% and 4.5 kg. When the pressure of the reactor reached 4 kg / cm 2, the reaction was terminated and the unreacted vinyl chloride monomer was recovered and removed. The average emulsification was 0.94 μm, TSC (total solid content) was 50%, and the scale was 100g or less. Polymerized latex was obtained.

[Comparative Example 1]

Except that the homogenization was carried out for 4 hours using a rotor-stator type homogenizer in Example 1, the average particle diameter was 0.54 μm, TSC (total solid content) was 35%, and an oil-soluble initiator. (Lauryl peroxide) content of 1.77% of the first seed latex was obtained.

Using the first seed latex, an average particle diameter of 0.73 μm, total solid content (TSC) of 50%, and a scale of seed emulsion latex for a flooring material of 100 g or less were obtained.

Comparative Example 2

In Example 1, homogenization was carried out using a rotor-stator type homogenizer for 4 hours, except that 5.6 kg of Sodium Dodecyl Benzene Sulfonate (15%) was added. A first seed latex of 0.75 μm, total solid content (TSC) of 35% and lauryl peroxide content of 1.77% was obtained.

Using the first seed latex, an average particle diameter of 0.91 μm, total solid content (TSC) of 50%, and a scale of seed emulsion latex for a flooring material of 1000 g or more were obtained.

Comparative Example 3

Except that the homogenization was carried out using a rotor-stator type homogenizer for 4 hours in Example 1 and 3.5kg of Sodium Dodecyl Benzene Sulfonate (15%) was added, the average particle diameter was 1.05. The first seed latex of 35 μm, total solid content (TSC) and lauryl peroxide content of 1.77% was obtained.

As a result of manufacturing the vinyl chloride-based resin using the first seed latex, the seed emulsion latex for flooring was agglomerated and excessively scaled due to deterioration in stability of the first seed latex.

Polymerization Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Seed1 Emulsifier amount (kg) 7.8 7.8 5.6 3.5 Homogenization time (hrs) 2 4 4 4 Average particle size (㎛) 0.77 0.54 0.75 1.05 Seed Emulsion Polymerization for Flooring Latex condition normal normal normal Abnormal (agglomeration) Average particle size (㎛) 0.94 0.73 0.91 Not measurable Polymerization scale (g) <100 <100 > 1000 Overdose

The measuring method used in the said Example is as follows.

1) Average particle diameter measurement

Average particle size was measured using a Microtrac UPA150 instrument.

Comparing Example 1 and Comparative Example 1, as a result of reducing the homogenization time it was possible to increase the average particle diameter of the resin produced by the seed and seed emulsion polymerization. At this time, even when the scale generation was compared, only the average particle diameter of the seed was increased, but the scale generation amount did not increase.

On the other hand, in Comparative Examples 2 and 3 in which the amount of the emulsifier is reduced, the average particle diameter of the first seed and the resin increases, but at the same time, a problem in that the polymerization scale increases.

Claims (7)

Vinyl chloride-based large diameter seeds having an average particle diameter of 0.65 to 1.5 µm. A method of preparing a vinyl chloride-based large diameter seed by adding a vinyl chloride monomer, an emulsifier, and a polymerization initiator to an aqueous medium and homogenizing the droplets using a homogenizer pump to control the seed particle size by adjusting the homogenization time. A method for producing a vinyl chloride-based large diameter seed. The method of claim 2, wherein the homogenization is performed for 1 hour to 3 hours. The method of claim 2, wherein the homogenizer pump is a rotor-stator type. A vinyl chloride-based large diameter seed, which is prepared by the method of any one of claims 2 to 4. A paste vinyl chloride-based resin prepared by seed emulsion polymerization using the vinyl chloride-based large-diameter seed of claim 1 or 5 as a first seed. The paste vinyl chloride-based resin according to claim 6, wherein the average particle diameter is 0.8-3.0 µm.