KR20130009718A - Vinyl chloride resin with low viscosity for foaming application and method of preparing the same - Google Patents

Abstract

PURPOSE: A vinylchloride resin for foaming with improved high shear and low shear viscosity and a manufacturing method thereof are provided to express low viscosity at high shear and low shear. CONSTITUTION: A vinylchloride resin for foaming is formed by polymerizing vinylchloride based small seed particles having the average particle diameter of 0.15-0.5 microns and vinylchloride based large seed particles having the average particle diameter of 0.51-0.8 microns. The large seed particle molar ratio based on the small seed particle is 1-2 weight ratio. The small seed particle is manufactured by emulsion polymerization.

Description

Vinyl chloride resin with low viscosity for foaming application and method of preparing the same}

The present invention relates to a vinyl chloride-based resin having excellent low viscosity characteristics and a method for preparing the same, and more particularly, seed seeds having different average particle diameters as seeds of the seed emulsion polymerization method, but having a small particle size. By adjusting the size, low viscosity characteristics can be realized at high shear and low shear.

Paste resins that are conventionally used for foaming the flooring material have two or more particles (large / small) of different sizes to have a low viscosity at low shear and high shear to provide ease of processing.

As a method of polymerizing paste resin used here, fine suspension polymerization, seed emulsion polymerization, etc. are used. In the case of fine suspension polymerization, it is difficult to control the particle size distribution, and thus, two or more vinyl chloride resin latexes having different sizes are usually mixed, and the reaction time is longer than that of the seed emulsion polymerization.

Seeds used for seed emulsion polymerization use different seed particles, usually two seeds, small seeds are prepared by emulsion polymerization, and large seeds are prepared by fine suspension polymerization. Large seeds are prepared by polymerizing monomer droplets using a homogenizer to which a vinyl chloride monomer, an emulsifier, an oil-soluble polymerization initiator are added and pressurized, or a homogenization pump of a rotor-stator type by centrifugal force.

Seed emulsion polymerization has the advantage of easy particle size control because it is made by using different seed particles, but the particle size of the final product is largely dependent on the particle size of the large seed prepared by fine suspension polymerization and the small seed prepared by emulsion polymerization. do. Conventionally, large seed particles of 0.5 to 0.8 mu m and small seed particles of 0.08 to 0.13 mu m have been used.

In seed emulsion polymerization, viscosity and foaming properties are controlled by adjusting the ratio of large seed to small seed. Here, the size of the small seed and the amount injected into the seed emulsion polymerization have a great influence on the foaming properties such as viscosity and foam cell density, resilience, and whiteness.

In general, a small seed may exhibit excellent foaming properties when it is added at least 2.5 pmn, but a small seed particle having a size of 0.08 to 0.13 μm, which is conventionally used, has a limitation in loading because it worsens the low shear viscosity. This may cause problems in the plasticity sol formulation and pumping in the product manufacturing plant.

The present invention is to solve the above-mentioned problems in preparing a vinyl chloride-based resin by polymerizing two kinds of seed particles having different particle sizes by seed emulsion polymerization.

An object of the present invention is to provide a vinyl chloride-based resin having improved high shear and low shear viscosity properties by controlling the particle size of small seeds used in the seed emulsion polymerization method.

Another object of the present invention to provide a method for producing a vinyl chloride-based resin having the above characteristics.

In addition, an object of the present invention is to provide a plastisol comprising the vinyl chloride resin.

In the present invention, when seed emulsion polymerization of two kinds of seed particles having different particle sizes to prepare a vinyl chloride-based resin, the particle size of the seed particles having a relatively small particle size is different from that of 0.08 to 0.13 μm, which is the level of conventional use. By adjusting, the low shear viscosity is deteriorated, and thus there is a limit to the input, thereby solving the problems that the vinyl chloride resin having low viscosity could not be produced.

According to the present invention, the particle size distribution of the paste vinyl chloride-based resin can be controlled by controlling the particle size of the small seed used in the seed emulsion polymerization, and the particles having the particle size of the controlled distribution are plastisol which is a semi-finished product of the paste product. The low shear and high shear viscosity of the resin will be lowered, and the excellent foaming properties will enable the development of resins to suit the working conditions of the company. It facilitates pumping operations and reduces the volume of volatile liquid side ingredients in plastisol formulations, offering the possibility of using low cost diluents and increasing filler inputs.

The vinyl chloride-based resin of the present invention for achieving the above object is made by polymerizing a vinyl chloride-based small seed particles having an average particle diameter of 0.15 ~ 0.5㎛, and a vinyl chloride-based large seed particles having an average particle diameter of 0.51 ~ 0.8㎛, The large seed particle content ratio (large seed particle content / small seed particle content) to the small seed particles is characterized by being 1 to 2 by weight.

In addition, the production method of the vinyl chloride-based resin of the present invention is a vinyl chloride-based small seed particles having an average particle diameter of 0.15 ~ 0.5㎛, vinyl chloride-based large seed particles having an average particle size of 0.51 ~ 0.8㎛, vinyl chloride monomer, emulsifier, and It is characterized in that it comprises the step of emulsion emulsion polymerization by adding an initiator.

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

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride-based resin having excellent low viscosity properties, and in a method of seed emulsion polymerization using a vinyl chloride monomer, an emulsifier, and an oil-soluble initiator, the use of a small seed in a specific range outside the size of a conventionally used range. It relates to a method for producing a resin excellent in viscosity and foaming properties.

In the present invention, two kinds of vinyl chloride seed are prepared in advance. First, the vinyl chloride seed having a small particle size is prepared by emulsion polymerization, and its particle size is 0.15 to 0.5 μm. Compared to conventionally used seeds having a small particle size having 0.08 to 0.13 μm, the vinyl chloride final resin prepared by seed emulsion polymerization using seeds having an average particle diameter in the range according to the present invention is used in the preparation of plastisol. It has the effect of lowering the viscosity, which enables the reduction of liquid raw materials and the production of high hardness products and excellent workability during processing.

 The method for preparing the vinyl chloride seed particles having a small size is according to a conventional emulsion polymerization, and the detailed description of the synthesis process is omitted in the present invention.

The vinyl chloride seed having a large particle size of the present invention is prepared by fine suspension polymerization, and has an average particle diameter of 0.51 to 0.8 μm. The method for producing a vinyl chloride-based seed having a large particle size according to the present invention is according to a conventional fine suspension polymerization, and the detailed description of the synthesis process is omitted in the present invention.

Vinyl chloride-based emulsion polymerization seeds having two different average particle size ranges as described above can be used to make the average particle diameter of the resin prepared finally, and two different seeds of microsuspension polymerization and emulsion polymerization that are commonly used. May be used at an appropriate ratio.

That is, the final particle size distribution may be adjusted by adjusting the seed particle loading ratio, and two seed latex doses which are commonly used may be 1.0 to 10.0 parts by weight relative to vinyl chloride monomer (commonly referred to as "VCM"). Can be. In the present invention, it is particularly preferable to adjust the content ratio of the large seed to the small seed to 1-2. When the content ratio of the large seed to the small seed is less than 1, the viscosity increase in the low shear region is large, which is not preferable. When the content exceeds 2, the viscosity increase occurs in the high shear region (Dilatancy), and foaming properties are also preferable. You won't be able to.

The vinyl chloride resin according to the present invention prepared by adding two kinds of seed particles having a different particle size as described above in a mixing ratio as described above usually has a particle size in the range of 0.1 to 4 μm, and average A vinyl chloride resin having a particle diameter of 0.8 to 1.5 mu m can be obtained.

On the other hand, the present invention is a vinyl chloride seed seed particles having an average particle size of 0.15 ~ 0.5㎛, and a vinyl chloride seed seed particles, a vinyl chloride monomer, an emulsifier, and an initiator with an average particle diameter of 0.51 ~ 0.8㎛ is added to the emulsion emulsion It provides a method for producing a low viscosity vinyl chloride resin through a step.

In the present invention, first, two kinds of vinyl chloride seed particles having different particle sizes are prepared. As described above, vinyl chloride-based seed particles having a large particle size are prepared by fine suspension polymerization to produce seed particles having an average particle diameter in the range of 0.51 to 0.8 μm.

In addition, the vinyl chloride seed particles having a small particle size are prepared by emulsion polymerization to prepare seed particles having an average particle diameter in the range of 0.15 to 0.5 μm. Potassium persulfate is widely used as a polymerization initiator in preparing small seeds.

Two kinds of vinyl chloride seed particles having different average particle diameters were prepared, and seed emulsion polymerization was performed by adding deionized water, a vinyl chloride monomer, the two kinds of vinyl chloride seed particles, an emulsifier, and an initiator to a high-pressure reactor, and then vinyl chloride. To prepare a latex.

The seed emulsion polymerization method is a conventional method, the reaction temperature is preferably 50 ~ 64 ℃. If the temperature is less than 50 ° C, the polymerization time becomes long, and if it exceeds 64 ° C, the pressure control is not easy.

In the seed emulsion polymerization, the vinyl chloride-based small seed particles and the vinyl chloride-based large seed particles are 1.0 to 10.0 parts by weight, the emulsifier 0.5 to 2 parts by weight, and the initiator is contained in the large seed to be added to 100 parts by weight of the vinyl chloride monomer. It is.

The emulsifier of the present invention is characterized in that the anionic emulsifier, nonionic emulsifiers or mixtures thereof, the anionic emulsifier to maintain the stability of the latex during polymerization, the nonionic emulsifier to achieve low viscosity properties Used. The anionic emulsifier is selected from the group consisting of carboxylic acid, alkyl sulfonic acid, alkyl benzene sulfonic acid, sulfo succinic acid, α-olefin sulfonic acid, and alkyl phosphoric acid.

The anionic emulsifier may be used 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.

Nonionic emulsifiers that can be used to control the viscosity include polyoxyethylene ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkenyl ether, polyoxyethylene derivatives, glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene Fatty acid esters, silicone-based emulsifiers, polyethylene glycol (glycol) and derivatives thereof, and polypropylene glycol (polyepropylene-glycol) and derivatives thereof. The nonionic emulsifier is not particularly limited in content, and may be used in an amount of up to 0.5 parts by weight based on 100 parts by weight of the vinyl chloride monomer.

The initiator according to the present invention is contained in a large seed, and in some cases, the additional initiator may add about 0.001% to 0.01% of a sulfate-based water-soluble initiator during the polymerization.

 In addition to the above composition, it is a matter of course that surfactants, fillers and other additives that can be included in the conventional seed emulsion polymerization within the range that does not impair the physical properties of the vinyl chloride-based resin of the present invention can be used.

Particle size distribution of the vinyl chloride produced by the production method of the present invention as described above has a bimodal distribution, and thus can be obtained the effect of viscosity reduction in both high shear and low shear, which is large and small When the polymerization is performed from the above seed particles, particles generated from small seeds of about 0.1 to 0.3 μm may cause high low shear viscosity, but also lower the viscosity at high shear and improve foaming properties. This is because the roles will be parallel.

Therefore, the selection of the size of the small seed particles, such as the present invention is an important key to lowering the viscosity in the high shear and low shear, in view of this point by controlling the size of the small seed particles as appropriate in the high shear And vinyl chloride-based resins having low viscosity characteristics in both low shear.

In general, low shear viscosity is important for plastisol compounding and transport, and high shear viscosity is important during coating, so it may be important to easily control the two viscosity.

In the case of the vinyl chloride-based resin having low viscosity characteristics as described above, the low shear and high shear viscosity of the plastisol, which is a semi-finished product of the paste product, is reduced, and the resin is suitable for the working conditions of the company because of excellent foaming properties. This enables low viscosity paste resin plastisol in flooring foam paste resin, which facilitates coating and pumping operations, reduces volatile liquid subsidiary ingredients when formulating plastisols, uses low-cost diluents, and increases the amount of additive input. Offers the possibility.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. , And it is natural that such variations and modifications fall within the scope of the appended claims.

Example  One

Vinyl chloride particles having a large seed particle size having a mean particle size of 0.7 μm and a polymerization initiator content of 1.8% were prepared using the fine suspension polymerization method. Vinyl chloride particles having small seed particle sizes having an average particle diameter of 0.2 μm were prepared by emulsion polymerization.

In a 200 L high-pressure reactor, 60 kg of deionized water, 80 kg of vinyl chloride monomer, 0.46 kg of sodium lauryl sulfate, and large seed particles and small seed particles were added so that the content ratio of vinyl chloride-based large seed particles / small seed particles was 1.5. The temperature of the high-pressure reactor was raised to 51 ° C. and seed emulsion polymerization was performed for 7 hours to prepare vinyl chloride-based latex having a particle size of 0.1 to 4 μm and an average particle size of 0.8 to 1.5 μm.

Example  2

Seed emulsion polymerization was carried out in the same manner as in Example 1, except that vinyl chloride-based small seed particles having an average particle size of 0.3 μm were used, and particles having a particle size in the range of 0.1 to 4 μm and an average particle size of 0.8 to 1.5 μm were used. Vinyl-based latex was prepared.

Comparative example  One

The above-mentioned implementation was carried out except that the vinyl chloride-based large seed particles having an average particle diameter of 0.5 µm and the vinyl chloride-based small seed particles having an average particle diameter of 0.1 µm were used, and the content ratio of the large seed particles to the small seed particles was added at 1.4. Seed emulsion polymerization in the same manner as in Example 1 to prepare a vinyl chloride-based latex.

Comparative example  2

Vinyl chloride-based latex was prepared by seed emulsion polymerization in the same manner as in Comparative Example 1, except that the average particle diameter of the vinyl chloride-based large seed particles was used.

Comparative example  3

The vinyl chloride-based latex was prepared by seed emulsion polymerization in the same manner as in Example 1, except that the content ratio of the large seed particles to the vinyl chloride-based small seed particles was 2.3.

[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: The average particle size was measured using a Microtrac UPA 150 instrument.

Low shear viscosity (Phesica Rheometer): 55 parts by weight of dioctylphthalate as a plasticizer, 100 parts by weight of filler, 80 parts by weight of viscosity reducing agent, stabilizer to 100 parts by weight of the powdery paste vinyl chloride resin prepared in Examples and Comparative Examples 2.5 parts by weight and 2 parts by weight of blowing agent were added thereto, stirred at 500 rpm for 10 minutes, and then mixed at 800 rpm for 10 minutes to prepare a paste sol, followed by vacuum defoaming and storage at 25 ° C. for 1 hour, and then measured at a shear rate of 1 / s as a cylinder type.

-High shear viscosity (Physica Rheometer): Viscosity was measured at a shear rate of 1000 / s in cylinder type.

- Foaming Cell: The coated paper was coated with plastisol, heated at 200 ° C for 2 minutes using a Matis oven, and visually distinguished using an optical microscope.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Large seed size (μm) 0.7 0.7 0.5 0.7 0.7 Small seed size (μm) 0.2 0.3 0.1 0.1 0.2 Seed content ratio
(Large seed / small seed) 1.5 1.5 1.4 2.5 2.3 Low Shear Viscosity (Pa.s) 7.4 8.1 19 9.3 7.6 High shear viscosity (Pa.s) 7.8 5.0 4.7 7.6 6.6 Foam Cell ◎ ○ ◎ ○ △

As shown in Table 1, the vinyl chloride resin of Example 1 prepared according to the present invention effectively suppresses the tendency of viscosity increase in the high shear region and significantly improves the viscosity of the low shear region.

As can be seen from the above results, since the viscosity and the foaming cell characteristics have opposite properties, it is very difficult to satisfy both. Comparative Example 1 has a high high shear viscosity, but low shear viscosity is a problem in operation, foam cell density is also low. Comparative Example 2 has a problem of excellent viscosity but difficult to be used as a product because the foaming cell is so deteriorated.

As a result of reducing the amount of small seed used in Comparative Example 3, fluidity was maintained similarly to Example 1, but adversely affected the foaming properties. Therefore, a small amount of more than an appropriate amount should be included to improve the foaming properties.

Claims (7)

It is made by polymerizing a vinyl chloride-based small seed particle having an average particle diameter of 0.15 to 0.5 µm and a vinyl chloride-based large seed particle having an average particle diameter of 0.51 to 0.8 µm. Vinyl chloride type resin, characterized in that 1-2. The vinyl chloride-based resin of claim 1, wherein the vinyl chloride-based small seed particles are prepared by emulsion polymerization, and the vinyl chloride-based large seed particles are prepared by fine suspension polymerization. The vinyl chloride-based resin of claim 1, wherein the vinyl chloride-based resin has a bimodal particle size distribution. The vinyl chloride resin of claim 1, wherein the vinyl chloride resin has a particle size of 0.1 to 4 µm and an average particle diameter of 0.8 to 1.5 µm. Chloride comprising the steps of emulsifying the seed by adding a vinyl chloride-based small seed particles having an average particle diameter of 0.15 to 0.5 µm, and a vinyl chloride-based large seed particles having an average particle diameter of 0.51 to 0.8 µm, a vinyl chloride monomer, an emulsifier, and an initiator. Method for producing vinyl resin. The vinyl chloride-based small seed particles and the vinyl chloride-based large seed particles are each contained in an amount of 1.0 to 10.0 parts by weight, and 0.5 to 2 parts by weight of an emulsifier, based on 100 parts by weight of the vinyl chloride monomer. Method for producing vinyl chloride resin. Flooring consisting of a plastisol containing a vinyl chloride-based resin according to claim 1.