KR20090117268A - Method for making vinyl chloride resin with enhanced stability in high temperature - Google Patents

Abstract

PURPOSE: A method for preparing a vinyl chloride resin is provided to control an average particle diameter of a paste vinyl chloride-based resin by seed micro suspension and to prepare a vinyl chloride-based resin with high storage stability at a high temperature. CONSTITUTION: A method for preparing a vinyl chloride resin uses a polyvinyl chloride-based latex with an average particle diameter of 65-1.5 micron as seeds in a seed emulsion polymerization method for preparing a chloride-based resin. The vinyl chloride-based latex seed is prepared by a micro-suspension polymerization method and includes 0.7-2% of a polymerization initiator.

Description

Method for making vinyl chloride resin with high temperature storage stability {Method for making Vinyl chloride Resin with enhanced stability in high temperature}

The present invention provides a method for producing a vinyl chloride-based resin for a vinyl chloride-based resin, specifically, a method for producing a vinyl chloride-based resin using a seed emulsion polymerization method using a vinyl chloride-based latex having a mean particle size of 0.65 µm to 1.5 µm as a seed. It is about.

Conventionally, products made by microsuspension polymerization have excellent high temperature storage stability and are used in areas where viscosity is important at high temperatures such as gloves, but microsuspension polymerization has a high manufacturing cost because the reaction time is relatively longer than seed emulsion polymerization. There is a problem that is formed.

In addition, in the related art, seed emulsion polymerization was performed using two kinds of seeds prepared in advance by microsuspension polymerization and emulsion polymerization to prepare a final vinyl chloride resin latex. Seeds prepared by emulsion polymerization have an average particle diameter of 0.1 to 0.2 µm, and seeds prepared by microsuspension polymerization, namely, vinyl chloride monomer, emulsifier, oil-soluble polymerization initiator, and a homogenizer using pressure or a sporaton using centrifugal force. A seed prepared by homogenization using a pump and then polymerized usually has an average particle diameter of about 0.5 to 0.6 mu m.

The paste vinyl chloride-based resin is prepared by seed emulsion polymerization in which seeds having different average particle diameters are introduced at the beginning of polymerization to grow as the vinyl chloride monomer reacts with the seeds to form final resin particles.

In general, the polymerized latex having an average particle diameter of about 0.65 to 1.3 μm is obtained by seed emulsification polymerization using the seed as described above. In this case, the seed having an average particle size of about 0.5 μm has been used as the largest seed particle. Such a seed has a reaction site by itself because the particle contains an oil-soluble polymerization initiator.

Paste vinyl chloride-based resin prepared by seed emulsion polymerization is used for the production of plastisol, the viscosity properties of the plastisol tends to depend on the average particle size of the paste vinyl chloride-based resin.

However, in the case of using a seed having a size of 0.5 μm conventionally used, the average particle diameter of the paste vinyl chloride-based resin is not largely adjusted, and there is a problem in that a fixed size resin is prepared.

Therefore, in order to maintain the viscosity stability of the plastisol, paste vinyl chloride-based resin having an average particle size increased and a vinyl chloride resin having a large particle size to reduce the contact area with a plasticizer in order to maintain storage stability at high temperature can be obtained. It has been requested.

The present invention provides a method for producing a vinyl chloride resin having improved viscosity properties and high storage stability at high temperatures.

According to the above object, in the seed emulsion polymerization method for producing a vinyl chloride-based resin, a vinyl chloride-based resin production method characterized in that the use of a vinyl chloride-based latex having an average particle diameter of 0.65 ㎛ to 1.5 ㎛ as a seed To provide.

 The present invention provides a vinyl chloride-based resin production method characterized in that the vinyl chloride-based latex seed is prepared by a microsuspension polymerization method.

The present invention provides a method for producing a vinyl chloride-based resin, characterized in that the vinyl chloride-based latex seed comprises 0.7 to 2% of a polymerization initiator in the particles.

The present invention provides a method for producing a vinyl chloride-based resin, characterized in that the vinyl chloride-based latex seed comprises at least one emulsifier selected from anionic emulsifiers and nonionic emulsifiers.

The present invention provides a method for producing a vinyl chloride-based resin, characterized in that for producing a vinyl chloride-based resin having an average particle size of 1.3 to 3㎛.

The present invention provides a method for producing a vinyl chloride-based resin, characterized in that the particle size distribution of the vinyl chloride-based resin is a unimodal distribution.

According to the present invention, the seed microsuspension polymerization can greatly control the average particle diameter of the paste vinyl chloride-based resin, and the particles thus made largely reduce the viscosity at room temperature and at high temperature of the plastisol, which is a semi-finished product of the paste product. It can be applied to PVC glove products that require great stability.

Hereinafter, the present invention will be described in detail.

The present invention relates to the production of vinyl chloride-based latex for paste vinyl chloride resin, and more particularly to a seed emulsion polymerization method using a seed containing a vinyl chloride monomer, emulsifier and initiator.

The present invention is characterized by improving the storage stability at high temperatures in the plastisol as a semi-finished product by controlling the particle size distribution of the final vinyl chloride-based polymerized latex by controlling the size of the seed particles to be used.

In the present invention, the average particle diameter of the resin can be largely controlled by using a vinyl chloride-based microsuspension polymerization seed having an average particle diameter of 0.65 μm to 1.5 μm prepared in advance by microsuspension polymerization. Instead of using the other two seeds, the present invention makes it possible to make the final particles obtained after polymerization unimodal and large, by using only seeds of large particles. Such a product has a viscosity-lowering effect in the production of plastisols, and further improves the storage stability at high temperatures, and thus can be applied to a product requiring high temperature storage stability such as a product for gloves.

In one embodiment of the present invention, a vinyl chloride seed latex having a preliminarily prepared average particle size of 0.65 μm to 1.5 μm is added to the polymerization in a predetermined ratio. By adjusting the said loading ratio, final particle size distribution can be adjusted. The amount of Sidratex can be used 2.5 ~ 8.0 phm relative to the monomer.

The present invention is characterized by excluding the emulsion polymerization seeds normally used for seed emulsion polymerization and using only relatively large fine suspension polymerization particles. According to the method of the present invention, the production of small particles is suppressed.

One embodiment of the present invention may add an additional emulsifier or water in the seed to maintain the polymerization stability of large particles. In this way, a vinyl chloride final particle having a particle size range of 0.5 to 7 μm and having an average particle size of 1.3 to 3 μm is produced.

 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 in an amount of 0.5 to 1.5 parts 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.

In addition, a nonionic emulsifier may be used to control viscosity properties. 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 microsuspension polymerization of the seed, may be continuously added to the aqueous medium during the polymerization reaction, may be added to the latex after the polymerization reaction is completed, if necessary by combining the above method Can be used. This polymerization allows the emulsifier to be included in the prepared seeds.

Polymerization initiators used in the microsuspension polymerization seeds 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 can be used.

In addition, the vinyl chloride-based seed used has a content of 0.7 to 2% of the polymerization initiator in the particles, and the content of the polymerization initiator can be adjusted according to the use, reaction time according to the heat removal capacity of the reactor, and particle size distribution of the final particles. . In the case of the polymerization initiator content, the polymerization has a stable effect.

Particles of vinyl chloride produced by the production method of the present invention is characterized in that the particle size distribution shows a unimodal distribution.

As is commonly used, if the polymerization from two or more seed particles, large and small, particles generated from small seeds, such as 0.1 ㎛ causes a high viscosity, according to the production method of the present invention Is to exclude.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely illustrative of the present invention, and various changes and modifications within the scope and spirit of the present invention are apparent to those skilled in the art. Naturally, such modifications and variations fall within the scope of the appended claims.

Example  One

<Production of Vinyl Chloride Seed>

After adding 320 kg of deionized water, 352 kg of vinyl chloride monomer, 6.42 kg of lauryl peroxide, 4.2 g of paraquinone, 7 kg of lauryl alcohol, 2.9 kg of sodium lauryl sulfate as a initiator, Low pressure was homogenized by adjusting to 550 + 550 psi. The vinyl chloride-based seed latex was prepared by raising the temperature of the high pressure reactor to 43 ° C. and suspending polymerization for 9 hours. At this time, in order to control the intensity of the reaction, 0.25% paraquinone as a reaction inhibitor is appropriately continuously added according to the reactor OP value (difference value between the value set in the reactor control and the actual value in the reaction) in the reaction state. It was.

The prepared vinyl chloride-based seed had an average particle diameter of 0.84 μm and a polymerization initiator content of 1.77% in the particles.

<Production of vinyl chloride latex>

In a 200 L high pressure reactor, 60 kg of deionized water, 80 kg of vinyl chloride monomer, 4.5 phm of the prepared vinyl chloride seed, sodium lauryl sulfate content of 0.46 kg, and the temperature of the high pressure reactor were raised to 50.5 ° C. for 7 hours. Seed emulsion polymerization to prepare a vinyl chloride-based latex.

Example  2

Vinyl chloride-based latex was prepared in the same manner as in Example 1, except that the amount of seed used was increased by 20% from Example 1.

Example  3

Polymerization was carried out in the same manner as in Example 1, except that seed particles having an average particle diameter of 0.65 μm were used in Example 1.

Comparative example  One

In Example 1, polymerization was carried out in the same manner as in Example 1, except that an emulsion polymerization seed of 0.12 μm and a suspension polymerization seed of 0.54 μm were used together in a 1: 1 ratio.

Comparative example  2

Polymerization was carried out in the same manner as in Example 1, except that in Example 1, a suspension polymerization seed having a thickness of 0.54 µm was used alone.

[Test Example]

The average particle diameter and viscosity of the vinyl chloride polymers prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 1 below.

* Average particle size-Particle Size Analyser 2000 using laser diffraction technology (manufactured by Malvern) was used to measure the size of the particles in a state in which the vinyl chloride seed was exposed to a small amount of ultrasonic waves to suppress aggregation between the particles.

* Brookfield (BF viscosity)-60 parts by weight of dioctylphthalate as a plasticizer was added to 100 parts by weight of the vinyl chloride resin powder prepared in Examples 1 and Comparative Examples 1 or 2, followed by mixing at 800 rpm for 10 minutes. After the sol was prepared, vacuum defoaming was performed at a Brookfield viscometer and stored at 25 ° C. for 1 hour, and then measured at 6 rpm.

* Viscosity at high temperature-90 parts by weight of dioctylphthalate as a plasticizer was added to 100 parts by weight of the powdery paste vinyl chloride resin prepared in Examples 1 and 2 or 2, followed by mixing at 800 rpm for 10 minutes to prepare a paste sol. The viscosity was measured after 90 minutes at 67.7 ° C using a Physica Rheometer Cylinder Type.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Latex Average Particle Size (㎛) 2.0 1.7 1.4 0.9 1.2 BF (cps) 4000 4500 5300 7500 6000 High Temperature Viscosity (cps) 4200 7000 11000 50000 15000

As shown in Table 1, the vinyl chloride resins of Examples 1 to 3 prepared according to the present invention increased in size compared to conventional resins, and had an adverse effect on high temperature storage stability when the plastisol was stored at high temperature. The content of small particles that increase the viscosity is also significantly lowered.

In Example 2, as a result of increasing the amount of the seed used, the overall particle size of the polymer was smaller than that in Example 1. This is because the initiator is entirely contained in the seed.

Claims (6)

In the seed emulsion polymerization method for producing a vinyl chloride-based resin, a vinyl chloride-based resin production method characterized by using a vinyl chloride-based latex having an average particle diameter of 0.65 ㎛ to 1.5 ㎛ as a seed. The method of claim 1, wherein the vinyl chloride latex seed is prepared by a microsuspension polymerization method. The method of claim 1, wherein the vinyl chloride latex seed comprises 0.7 to 2% of a polymerization initiator in the particles. The method of claim 1, wherein the vinyl chloride-based latex seed comprises at least one emulsifier selected from anionic emulsifiers and nonionic emulsifiers. The method for producing a vinyl chloride resin according to claim 1, wherein a vinyl chloride resin having a mean particle size of 1.3 to 3 mu m is produced. The method of claim 5, wherein the particle size distribution of the vinyl chloride-based resin is a unimodal distribution.