KR101550954B1 - Method of preparing polyvinyl chloride resin - Google Patents

Abstract

The present invention relates to a method for preparing a vinyl chloride resin which controls the particle size of a vinyl chloride resin by controlling the size of small particles and large particles through control of the time of introduction of an emulsifier and introduction of a water-soluble initiator.

Description

TECHNICAL FIELD The present invention relates to a method of preparing a polyvinyl chloride resin,

The present invention relates to a process for producing a vinyl chloride resin, and more particularly, to a process for producing a vinyl chloride resin, which comprises controlling the particle size of small particles and large particles by controlling the time of introduction of an emulsifier and introducing a water- And a manufacturing method thereof.

In general, the vinyl chloride resin is divided into a straight vinyl chloride resin and a paste vinyl chloride resin according to a polymerization method. The straight vinyl chloride resin is a powder particle having a size of about 30 to 200 mu m and is produced by a suspension polymerization method. The paste vinyl chloride resin is powder particles having a size of about 0.01 to 5 mu m and is subjected to fine suspension polymerization, emulsion polymerization or seed emulsion polymerization . In addition, the straight resin is processed by a calender method, and the paste resin is processed by a method such as coating or dipping.

The paste vinyl chloride resin may be prepared by emulsion polymerization or seed emulsion polymerization in a polymerization system containing a polymerization initiator, an emulsifier (surfactant), a catalyst and other additives in a monomer mixture capable of copolymerizing vinyl chloride alone or vinyl chloride, , I.e., an emulsion state) is prepared and dried to obtain a powdery resin.

On the other hand, in order to control the particle size and content in the production of the vinyl chloride resin, the content of the emulsifier is important, and it is difficult to obtain the desired particle size and content by itself. Particularly, seed emulsion polymerization has a dominant influence on seed size and feed amount.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems of the prior art, and it is an object of the present invention to provide a vinyl chloride resin composition which can not produce desired particle size and content only by controlling the amount of initial emulsifier, It is possible to adjust the size and content of small sized particles freely according to the desired properties and applications by solving the problem that it is difficult to adjust the physical properties of the resin to the application, and further, a method of controlling the particle size of the vinyl chloride resin .

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

In order to accomplish the object of the present invention, 0.001 to 10 parts by weight of an emulsifier and a water-soluble initiator are added based on 100 parts by weight of a vinyl chloride monomer, followed by seed emulsion polymerization. The emulsifier is heated immediately after completion of heating, Of the total amount of the vinyl chloride resin is continuously added immediately after the elapse of time.

As described above, according to the present invention, it is possible to freely adjust the size and content of small-sized particles according to desired properties and applications, and additionally, shortening of polymerization time can be obtained. When the emulsifier is added at the same time as the polymerization is started, a new micelle is formed to increase the content of the small particles. When the emulsifier is added at the start of the polymerization, a new micelle The small particles are grown.

The present inventors have found that the content of an emulsifier is important in controlling the size and content of particles in the production of a vinyl chloride resin. However, the present invention overcomes the difficulty in obtaining the desired particle size and content, To induce the formation of new particles, a water-soluble initiator was added to induce the formation of new particles in the early stage of polymerization.

In order to understand the influence of the water-soluble initiator on the small particle size and the content, the two kinds of water-soluble initiators are varied and the change of the particle size distribution is confirmed by controlling the injection timing of the continuous emulsifier.

Hereinafter, the present invention will be described in detail.

The method for producing a vinyl chloride resin according to an embodiment of the present invention is characterized in that 0.001 to 10 parts by weight of an emulsifier and a water-soluble initiator are added based on 100 parts by weight of a vinyl chloride monomer, followed by seed emulsion polymerization. Or immediately after a lapse of 1 hour or more after the temperature rise.

The emulsifier may be in an appropriate range depending on the emulsifying ability of the emulsifier, but it is difficult to obtain latex because it is difficult to form micelles when it is added in a range of 0.1 to 1 part by weight and too little is added. It is difficult to obtain normal latex because of the problem. The water-soluble initiator is used in the range of 0.001 to 10 parts by weight, and the proper amount of the water-soluble initiator varies depending on the polymerization method. In the case of emulsion polymerization, there is a problem that the polymerization is not proceeded if the amount is too small, and when the amount is too large, the particles become very small and the transfer of the resin after drying becomes difficult and the reaction becomes strong. However, microseed polymerization (MSP) polymerization or suspension polymerization using other oil-soluble initiators does not cause any problems even if a water-soluble initiator is not used.

The water-soluble initiator may be one selected from the group consisting of potassium persulfate (KPS), ammonium persulfate (APS), sodium persulfate, and hydrogen peroxide. More specifically, potassium persulfate, Ammonium persulfate may be used, but is not limited thereto.

The emulsifier may be selected from the group consisting of sodium lauryl sulfate (SLS), sodium dodecyl benzene sulfate (SDBS), ammonium lauryl sulfate (ALS), sodium cetyl stearyl sulfate sodium lauryl ether sulfate (SLES), and succinate. More specifically, sodium lauryl sulfate or sodium dodecylbenzenesulfate is used. But is not limited thereto.

The vinyl chloride monomer may be used alone or in combination with a vinyl chloride monomer and a copolymerizable monomer. Examples of the monomer copolymerizable with the vinyl chloride monomer include vinyl acetate, acrylates, methacrylates, ethylene, propylene, acrylic acid, methacrylic acid, itaconic acid, maleic acid, and anhydrides thereof. Mix two or more of these.

The emulsion polymerization is carried out in the presence of a polymerization seed having a solid content of 20 to 60% and an average particle size of 0.4 to 1 탆, a polymerization seed having a solid content of 20 to 60% and an average particle size of 0.1 to 0.4 탆 in a ratio of 0.1: 1 to 10: 1 Seed emulsion polymerization can be carried out by using a seed mixture which is contained in a ratio of < RTI ID = 0.0 >

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 scope and spirit of the invention as disclosed in the accompanying claims. Changes and modifications may fall within the scope of the appended claims.

[Example]

Example  One

Vinyl chloride series  Latex and Powder phase  Manufacture of paste vinyl chloride resin

A 500 L high pressure reactor was charged with 76 phm (per hundred monomers) of vinylphosphonic monomer, 0.9 phm of sodium laurylsulfate emulsifier and 0.001 phm of water-soluble initiator potassium persulfate (KPS) The vinyl chloride latex was prepared by seed emulsion polymerization. The sodium lauryl sulfate emulsifier was added continuously for 4 hours from 5 minutes after the completion of the heating. The large seed used had an average particle diameter of 0.7 mu m and the small seed had an average particle diameter of 0.2 mu m.

Example  2

A vinyl chloride latex and a powder phase paste vinyl chloride resin were prepared in the same manner as in Example 1, except that ammonium persulfate (APS) was used as the water-soluble initiator in Example 1.

Example  3

A vinyl chloride latex and a powder phase paste vinyl chloride resin were prepared in the same manner as in Example 1 except that the water-soluble initiator was ammonium persulfate (APS) and the charge amount was 0.01 phm.

Example  4

The procedure of Example 3 was repeated except that the water-soluble initiator was ammonium persulfate (APS) and the continuous emulsifier was added for 1 hour to 4 hours after the completion of the heating, thereby obtaining a vinyl chloride latex and powder phase Paste vinyl chloride resin was prepared.

Example  5

Vinyl chloride-based latex and powdered-phase vinyl chloride resin were prepared in the same manner as in Example 4, except that the injection time of the continuous emulsifier was changed from 2 hours to 2 hours and 30 minutes after completion of the heating.

Example  6

A vinyl chloride latex and a powder phase paste vinyl chloride resin were prepared in the same manner as in Example 5, except that the water-soluble initiator was potassium persulfate.

Example  7

A vinyl chloride latex and a powdery phase paste vinyl chloride resin were prepared in the same manner as in Example 5, except that the amount of the emulsifier was 0.7 phm.

Comparative Example  One

A vinyl chloride latex and a powdery phase paste vinyl chloride resin were prepared in the same manner as in Example 1, except that the water-soluble initiator was not added in Example 1.

[Test Example]

The physical properties of the polymer were evaluated as follows using the following methods for the average particle size and the small particle ratio of the vinyl chloride-based polymer prepared in Examples and Comparative Examples, and the results are shown in Table 1 below.

* Average particle size: The particle size of the prepared vinyl chloride latex was measured using Microtrac nanotrac150.

* Small Particle Ratio: The volume ratio of the particles having a size of not larger than 0.4 mu m in the particle size distribution was calculated from the particle size distribution data.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative Example 1 Polymerization method MSP ^Note) MSP MSP MSP MSP MSP MSP MSP Initiator type KPS APS APS APS APS KPS APS No entry Initiator input
(phm) 0.0013 0.0013 0.013 0.013 0.013 0.013 0.013 No entry When the continuous emulsifier is added Immediately after warming up Immediately after warming up Immediately after warming up After 1 hour of heating After 2 hours of heating After 2 hours of heating After 2 hours of heating Immediately after warming up Emulsifier input
(phm) 0.9 0.9 0.9 0.9 0.9 0.9 0.7 0.9 Polymerization time
(min) 308 315 282 312 299 305 302 331 Average particle diameter (占 퐉) 0.688 0.690 0.550 0.826 0.841 0.832 0.860 0.729 Small particle
ratio(%) 51 52 63 36 35 40 32 46

MSP: Micro Seed Polymerization

As shown in Table 1, it can be seen that the use of a water-soluble initiator and the timing of injecting an emulsifier in the same polymerization method play an important role in controlling the ratio of the small particles and controlling the average size of the whole particles. Comparing Examples 3, 4 and 5 with Comparative Example 1, it can be seen that when the time point of introduction of the emulsifier is one hour or more, even when a large amount of water-soluble initiator is added, the ratio of small particles is not greatly increased. It was confirmed that when the emulsifier is injected, it has the greatest influence on the generation of small particles. Also, it can be seen from the comparison between Examples 2 and 3 that when the amount of the water-soluble initiator is increased, the reaction time is shortened and the relatively small particles are produced when the emulsifier is added immediately after the reaction. It can be seen that APS having a low half-life temperature and high reactivity is more effective in terms of polymerization time and small particle size and content. In Example 7 in which the amount of the emulsifier was somewhat reduced, the fine content could be reduced to make the particles larger. Using this method, it can be seen that smaller particles are produced more by controlling the ratio of small particles according to the application and processing method.

Claims (4)

Wherein the emulsifier and the water-soluble initiator are added in an amount of 0.001 to 10 parts by weight based on 100 parts by weight of the vinyl chloride monomer, and the emulsifier is continuously added for 5 minutes to 2 hours after the completion of the heating. ≪ / RTI > The method according to claim 1,
Wherein the water-soluble initiator is at least one selected from the group consisting of potassium persulfate, ammonium persulfate, sodium peroxalate, and hydrogen peroxide. The method according to claim 1,
The emulsifier may be selected from the group consisting of sodium lauryl sulfate (SLS), sodium dodecyl benzene sulfate (SDBS), ammonium lauryl sulfate (ALS), sodium cetyl stearyl sulfate wherein at least one selected from the group consisting of sodium sulfate, sodium lauryl ether sulfate (SLES) and succinate is selected. The method according to claim 1,
Wherein the emulsifier is 0.1 to 1 part by weight based on 100 parts by weight of the vinyl chloride monomer.