KR20210086152A - Method for preparation of chlorinated polyvinylchloride - Google Patents

Abstract

The present invention is to provide a method for producing chlorinated polyvinyl chloride, which uses a UV LED as a light source, increases production efficiency of the chlorinated polyvinyl chloride by adjusting a radiation angle, and also increases the physical properties of the produced chlorinated polyvinyl chloride.

Description

The manufacturing method of chlorinated polyvinyl chloride {Method for preparation of chlorinated polyvinylchloride}

The present invention relates to a method for producing chlorinated polyvinyl chloride using an ultraviolet LED.

Chlorinated polyvinyl chloride has excellent heat resistance and is used in various fields such as pipes, films, and sheets. Chlorinated polyvinyl chloride is produced by reacting polyvinyl chloride with chlorine. In general, chlorine radicals must be generated in order for chlorine to react with polyvinyl chloride, and UV irradiation is required for this purpose.

Until now, in the production of chlorinated polyvinyl chloride, the most common method used for UV irradiation is to use a mercury UV lamp. Mercury UV Lamps are widely used because they are inexpensive and easily available, but they have a problem that they have to be replaced frequently due to their low energy efficiency and short lifespan. In addition, ultraviolet rays are emitted from the mercury UV lamp in a radiation form, and accordingly, the ultraviolet rays do not sufficiently reach the reactants, which causes a problem in that the reaction efficiency is lowered.

Accordingly, the present inventors have made diligent efforts to solve the above problems, as will be described later, using UV LED as a light source and adjusting the radiation angle to increase the production efficiency of chlorinated polyvinyl chloride as well as to increase the production efficiency of the chlorinated polyvinyl chloride. The present invention was completed by confirming that the physical properties of polyvinyl chloride can also be increased.

The present invention uses a UV LED as a light source and also adjusts the radiation angle to increase the production efficiency of chlorinated polyvinyl chloride as well as increase the physical properties of the produced chlorinated polyvinyl chloride. Preparation of a method for producing chlorinated polyvinyl chloride to provide a way.

In order to solve the above problems, the present invention provides a method for producing the following chlorinated polyvinyl chloride:

1) introducing a reactant containing polyvinyl chloride and chlorine into the reactor; and

2) In the method for producing chlorinated polyvinyl chloride, comprising the step of irradiating the reactant with ultraviolet rays while stirring the reactant,

The ultraviolet irradiation uses an ultraviolet LED disposed in the reactor as a light source,

The radiation angle of the light source is 45 ° to 110 °,

A method for producing chlorinated polyvinyl chloride.

Polyvinyl chloride can be reacted with chlorine to produce chlorinated polyvinyl chloride, and chlorinated polyvinyl chloride has improved heat resistance compared to polyvinyl chloride, and is used in various fields such as pipes, films, and sheets. In order to produce such chlorinated polyvinyl chloride, chlorine radicals must be generated, and ultraviolet irradiation is required for this purpose.

Conventionally, a mercury UV lamp has been used as a light source for ultraviolet irradiation, but there is a problem in that the energy efficiency is low and the lifespan is short, so that it must be frequently replaced. Therefore, in the present invention, an ultraviolet LED is used as a light source, but due to the high light energy of the ultraviolet LED, there is a risk of deterioration of physical properties due to the generation of _{double bonds or CCl 2 bonds in the manufacturing process of chlorinated polyvinyl chloride.} As such, it is characterized in that the radiation angle of the light source is adjusted.

Step 1 is a step of introducing a reactant containing polyvinyl chloride and chlorine into the reactor, and is a step of preparing the reaction of step 2 to be described later.

The reactor is not particularly limited as long as it is used for producing chlorinated polyvinyl chloride. In addition, the reactor may be provided with a device capable of adjusting the conditions required for the reaction of the reactants by having a temperature control device, a pressure control device, and the like. In addition, since polyvinyl chloride and chlorine are generally reacted with stirring, a stirrer may be provided inside the reactor.

Among the reactants, polyvinyl chloride is preferably introduced into the reactor as an aqueous suspension, and accordingly, the stirrer is preferably provided at the lower end of the reactor. The aqueous polyvinyl chloride suspension may be prepared by mixing polyvinyl chloride with water and suspending the polyvinyl chloride, and the polyvinyl chloride in the suspension may be adjusted to 1 to 90 wt%. In addition, the suspension may be prepared first and put into the reactor, or polyvinyl chloride and water may be sequentially or together added to the reactor and then stirred.

In addition, chlorine among the reactants may be introduced into the reactor in gaseous or liquid phase. On the other hand, since chlorine is consumed by the chlorination reaction to be described later, chlorine may be additionally supplied to the reactor during the chlorination reaction process, and this process can be controlled by monitoring the chlorination degree of polyvinyl chloride.

In addition, the input amount of the reactant may be appropriately adjusted in consideration of the size of the reactor and the like.

Step 2 is a step of performing a chlorination reaction by irradiating ultraviolet rays while stirring the reactants introduced into the reactor.

As for the temperature of the chlorination reaction, 55-95 degreeC is preferable. If the temperature of the chlorination reaction is less than 55 ° C., the chlorination reaction does not proceed sufficiently, and if it exceeds 95 ° C., deterioration of polyvinyl chloride proceeds and there is a possibility that physical properties may be reduced. In addition, since the temperature inside the reactor increases as the chlorination reaction proceeds, it is preferable to adjust the temperature inside the reactor to maintain the above range.

Meanwhile, ultraviolet light is irradiated for the chlorination reaction of step 2, and in particular, in the present invention, an ultraviolet LED is used as a light source.

One of the ultraviolet LEDs is disposed in the reactor, or a plurality of UV LEDs may be disposed as needed. In addition, as long as the ultraviolet light emitted from the ultraviolet LED can be irradiated to the reactants in the reactor, the arrangement position of the ultraviolet LED is not particularly limited. Preferably, it is preferable that the UV LED of the UV LED is disposed above the reactor so that the UV light can be effectively irradiated to the reactant.

The wavelength of ultraviolet rays emitted from the light source is not particularly limited as long as it enables the chlorination reaction, and is preferably 290 nm to 400 nm.

On the other hand, the radiation angle of the light source is 45 ° to 110 °. The term 'radiation angle' refers to a semi-apical angle appearing in a cone of ultraviolet rays emitted from the light source. If the radiation angle is less than 45°, the light output is too high, and there is a risk of deterioration of the physical properties of chlorinated polyvinyl chloride produced in the chlorination reaction. There are concerns. Preferably, the radiation angle of the light source is between 60° and 70°. The radiation angle is determined according to the refraction angle of the quartz lens installed in the light source, and the desired radiation angle can be adjusted by changing the quartz lens.

Preferably, the light output of the light source is 10 W to 80 W, more preferably 20 W to 40 W. Preferably, the ultraviolet intensity of the light source is 30 to 300 mW/cm ² . In this case, the light output and ultraviolet intensity of the light source means the sum of the light output and ultraviolet intensity of the plurality of light sources when there are a plurality of light sources.

The distance between the light source and the reactant may be appropriately adjusted in consideration of the light output and UV intensity, and preferably, the distance is 10 cm or less.

On the other hand, as the chlorination reaction proceeds through step 2, chlorinated polyvinyl chloride is produced, and the reaction time of the chlorination reaction can be controlled by monitoring the degree of chlorination of the polyvinyl chloride. Preferably, it is preferable to adjust until the chlorine content of the chlorinated polyvinyl chloride to be produced becomes 62 to 69%, 64 to 68%, or 66 to 67.5%. On the other hand, the chlorination reaction may be terminated by terminating the ultraviolet irradiation through the light source.

In addition, the present invention may further include the step of dehydrating and/or drying the chlorinated polyvinyl chloride produced through the chlorination reaction.

As in the examples to be described later, when chlorinated polyvinyl chloride is manufactured by the manufacturing method according to the present invention as described above, not only the manufacturing efficiency is high, but also physical properties such as coloration, thermal stability, and softening point of the prepared chlorinated polyvinyl chloride will be improved. can

As described above, the present invention can increase the production efficiency of chlorinated polyvinyl chloride by using UV LED as a light source and adjusting the radiation angle, as well as increase the physical properties of the produced chlorinated polyvinyl chloride.

Hereinafter, preferred examples are presented to help the understanding of the present invention, but the following examples are only illustrative of the present invention and the scope of the present invention is not limited to the following examples.

Example 1

1) Experiment 1-1

A 20 wt% polyvinyl chloride slurry was prepared by mixing polyvinyl chloride having a polymerization degree of 1000 (average molecular chain length of 1000 pieces; K Value 67) and deionized water, and then it was put into a 5 L reactor. In the reactor, one UV lamp (100 W) was installed at a position spaced apart by 1/2 of the upper radius of the reactor from the center of the upper part of the reactor.

When the input was completed, degassing was performed until the pressure inside the reactor became -0.9 bar or more while stirring at a constant speed of 400 to 1000 rpm to remove oxygen in the reactor. When the degassing was completed, the temperature was raised to 40° C., and chlorine gas was started to be introduced.

When chlorine was normally added, the UV lamp was operated to carry out the chlorination reaction. At this time, the reaction pressure was maintained at 0.5 to 4.0 bar, and the chlorination reaction was carried out at a reaction temperature of 50 to 95 °C.

When the input chlorine reached the target value during the chlorination reaction, the UV irradiation was terminated to terminate the reaction. After the reaction was completed, the unreacted residual chlorine was removed with sufficient nitrogen, the chlorinated polyvinyl chloride slurry was dehydrated, and the slurry was prepared again with deionized water, neutralized using a neutralizing agent (sodium carbonate), and then dehydrated and dried to obtain a powdery state. Chlorinated polyvinyl chloride was prepared.

2) Experiment 1-2 to 1-7

A chlorinated polyvinyl chloride was prepared in the same manner as in Experiment 1-1, except that the UV LED lamp was changed and used as shown in Table 1 below.

Each of the physical properties of the prepared chlorinated polyvinyl chloride was evaluated by the following method.

(1) Processing coloration: Whiteness (White Index, WI) and yellowness (Yellow Index, YI) were measured using a colorimeter.

(2) Thermal stability: The time of discoloration to black was measured by setting the oven temperature to 195° C. using a Mathis Oven and ejecting the sample at a rate of 23 mm/10 min.

③ Vicat softening point: In accordance with KS M ISO 306:2015, it was measured at a temperature increase rate of 50°C and a load of 50N.

④ Chlorine content: CHNS element content was measured using an elemental analyzer.

The results are shown in Table 1 below.

Experiment 1-1 Experiment 1-2 Experiment 1-3 Experiment 1-4 Experiment 1-5 Experiment 1-6 Experiment 1-7 reaction
Condition Lamp output (W/EA) 100 5 2 5 2 5 2 Lamp total power (W) 100 100 40 100 40 100 40 Number of Lamps (pcs) One 20 20 20 20 20 20 Radiation angle (°) radial 110 110 60 60 45 45 UV intensity (mW/cm ² ) 40 80 35 170 70 230 110 Chlorination reaction time (min) 137 135 160 95 115 116 123 Total reaction time (min) 218 210 254 147 179 180 196 Properties processing coloring WI 11.3 8.5 12.3 10.2 16.7 9.2 10.2 YI 20.9 24.4 20.5 21.3 18.9 23.0 21.2 Thermal stability (min) 65 55 60 60 72 52 55 Vicat softening point (℃) 115.3 114.1 115.2 115.1 115.8 114.7 114.3 Chlorine content (wt%) 67.1 67.2 67.2 67.1 67.3 67.2 67.1

Example 2

Chlorinated polyvinyl chloride was prepared in the same manner as in Experiment 1-1, except that a 200 L reactor was used as the reactor and the UV LED lamp was changed as shown in Table 2 below (Experiment 2-1 to 2- 7).

Each of the physical properties of the prepared chlorinated polyvinyl chloride was evaluated in the same manner as in Example 1, and the results are shown in Table 2 below.

Experiment 2-1 Experiment 2-2 Experiment 2-3 Experiment 2-4 Experiment 2-5 Experiment 2-6 Experiment 2-7 reaction
Condition Lamp output (W/EA) 200 5 One 5 One 5 One Lamp total power (W) 400 400 80 400 80 400 80 Number of Lamps (pcs) 2 80 80 80 80 80 80 Radiation angle (°) radial 110 110 60 60 45 45 UV intensity (mW/cm ² ) 65 75 20 160 35 225 50 Chlorination reaction time (min) 126 123 201 83 110 109 143 Total reaction time (min) 192 199 343 123 166 161 220 Properties processing coloring WI 13.3 10.6 14.0 13.1 18.2 10.0 12.1 YI 20.3 22.0 19.9 20.3 18.7 22.8 21.7 Thermal stability (min) 67 60 61 65 75 50 58 Vicat softening point (℃) 115.3 114.2 114.6 115.2 116.1 114.3 114.8 Chlorine content (wt%) 67.3 67.4 67.4 67.4 67.4 67.2 67.4

Claims (10)

1) introducing a reactant containing polyvinyl chloride and chlorine into the reactor; and
2) In the method for producing chlorinated polyvinyl chloride, comprising the step of irradiating the reactant with ultraviolet rays while stirring the reactant,
The ultraviolet irradiation uses an ultraviolet LED disposed in the reactor as a light source,
The radiation angle of the light source is 45 ° to 110 °,
A method for producing chlorinated polyvinyl chloride.
According to claim 1,
The radiation angle is 60 ° to 70 °,
manufacturing method.
According to claim 1,
The wavelength of ultraviolet rays emitted from the light source is 290 nm to 400 nm,
manufacturing method.
According to claim 1,
The light output of the light source is 10 W to 80 W,
manufacturing method.
According to claim 1,
The light output of the light source is 20 W to 40 W,
manufacturing method.
According to claim 1,
The UV intensity of the light source is 30 to 300 mW / cm ² of,
manufacturing method.
According to claim 1,
The ultraviolet LED is arranged in plurality in the reactor,
manufacturing method.
According to claim 1,
The distance between the light source and the reactant is 10 cm or less,
manufacturing method.
According to claim 1,
The step 2 is carried out until the chlorine content of the chlorinated polyvinyl chloride to be prepared is 62 to 69%,
manufacturing method.
According to claim 1,
Further comprising the step of dehydrating and / or drying the prepared chlorinated polyvinyl chloride,
manufacturing method.