KR100465881B1 - Process of High Flow Thermoplastic Resin Having Good Moldability - Google Patents

Abstract

In the high flow thermoplastic resin of the present invention, the total flow rate of the styrene monomer is introduced into the first and second reactors in the first reactor is F, the total flow rate of the raw material solution is introduced into the first reactor, F ₁ , and the raw material solution is the second reactor. F = F ₁ + F ₂ , F = 12, 6.1 when the total flow rate into the reactor is F ₂ , the reactor volume of the first reactor is V ₁ , and the volume of the reaction solution in the first reactor is V ₁ ′. Continuous bulk polymerization under the conditions ≦ F ₁ / F ₂ ≦ 7.0 and 1.9 ≦ V ₁ / V ₁ ≦≦ 2.9; When the content of the reactor in the second reactor is V ₂ and the content of the reaction solution in the second reactor is V ₂ ′, 1.3 ≤ V ₂ / V ₂ '≤ 1.8, F = F ₁ + F ₂ Continuous bulk polymerization under the conditions of and continuously adding 1.5 to 2.3% by weight of the hydrocarbon compound based on the final pellets; When the reactor volume of the third reactor in the third reactor is V ₃ and the volume of the reaction solution in the third reactor is V ₃ ′, continuous bulk polymerization is carried out under the condition of V ₃ / V ₃ '= 1; And it is prepared by the step of separating the unreacted monomer from the polymer produced from the third reactor and then cut into pellets, the average molecular weight is 16-200,000, the fluidity is 11.0 ~ 15.0, the yellowness is 1.0 or less.

Description

Process of High Flow Thermoplastic Resin Having Good Moldability

Field of invention

The present invention relates to a method for producing a high flow thermoplastic resin having excellent release properties. More specifically, the present invention controls the residence time by adjusting the reaction conditions in the first reactor, the reaction conditions are adjusted to reduce the high temperature and reaction time in the second reactor, the high temperature continuous mass in the third reactor By preparing a thermoplastic resin having a certain range of solids (polystyrene) content and a molecular weight within a specific range by polymerization, the yellowness is good, the fluidity is excellent, and the releasability is greatly improved, so that food and beverage containers, audio product cases, and refrigerators The present invention relates to a method for producing a high flow thermoplastic resin useful for the production of parts, sundries and the like.

Background of the Invention

In general, high-flow polystyrene has been used to manufacture food and beverage containers, audio product cases, refrigerator internal parts, and general merchandise containers. The manufacturing process for producing such high-flow polystyrene proceeds by solution polymerization, and there are methods for polymerizing all the raw material solutions by adding them to the first reactor, and the methods are well known through Japanese and US patent documents. However, since the above methods are reacted by solution polymerization using solvents (EB, MEK), polystyrene, which has transparency as the best condition, brings about lowering of the product.

In order to solve the problems of the prior art, the present inventors have developed a method for producing a polystyrene resin having good yellowness and excellent fluidity by continuous bulk polymerization in three reactors.

An object of the present invention is to provide a method for producing a thermoplastic resin excellent in fluidity.

Another object of the present invention is to provide a method of producing a high flow thermoplastic resin useful in the manufacture of food and beverage containers, audio product cases, refrigerator internal parts, general merchandise containers, etc., as well as good yellowness and excellent fluidity. It is for.

Both the above and other objects of the present invention can be achieved by the present invention described below. Hereinafter, the content of the present invention will be described in detail.

1 is a schematic diagram schematically showing a continuous block polymerization apparatus for producing a high flow thermoplastic resin having excellent release properties according to the present invention.

Brief description of the main symbols in the drawing

1: total flow rate (F) in which styrene monomer is introduced into the first and second reactors

2: total flow rate of the styrene monomer to the first reactor (F ₁ )

3: total flow rate of the styrene monomer to the second reactor (F ₂ )

4: reactor content of the first reactor (V ₁ )

5: the volume of the reaction solution in the first reactor (V ₁ ')

6: reactor volume of the second reactor (V ₂ )

7: Content (V ₂ ') of the reaction solution in the second reactor

8: reactor volume in the third reactor (V ₃ )

9: the internal volume of the reaction solution in the third reactor (V ₃ ')

Summary of the Invention

In the high flow thermoplastic resin of the present invention in the production of polystyrene by mass polymerization of styrene monomer (raw material solution) in the first reactor, the second reactor and the third reactor, by adjusting the ratio of the total flow rate of the styrene monomer It is manufactured by separating and adding the first reactor and the second reactor.

In the first reactor, a core reaction for producing polystyrene having an appropriate molecular weight, which is a condition for producing styrene monomer into a high flow resin, proceeds, and in the second reactor, the first reactant is polymerized at a high temperature to continuously react the reactant of the first reactor. In order to produce polystyrene which is relatively lower than the molecular weight in, and to give the resin excellent flow characteristics and release property, an appropriate amount of hydrocarbon compound extracted from petroleum is added. In the third reactor, the polymer is polymerized at a high temperature to produce polystyrene having an appropriate molecular weight which may have a desired fluidity, and the ratio of the final solid content is increased.

The high flow thermoplastic resin according to the present invention is subjected to continuous bulk polymerization while maintaining the styrene monomer input flow rate and reaction time in the first reactor under the conditions of the following formulas (A) to (C); Continuous block polymerization while maintaining the reaction conditions in the second reactor under the conditions of the following formula (D); It is prepared by continuous bulk polymerization while maintaining the reaction conditions in the third reactor under the condition of the following formula (E): and separating the unreacted monomers from the polymer (solids) produced in the third reactor:

F = F ₁ + F ₂ , F = 12 (A)

6.1 ≤ F ₁ / F ₂ ≤ 7.0 (B)

1.9 ≤ V ₁ / V ₁ '≤ 2.9 (C)

1.3 ≤ V ₂ / V ₂ '≤ 1.8 (D)

V ₃ / V ₃ '= 1 (E)

In the above formula, F is the total flow rate of the styrene monomer to the first, second reactor, F ₁ is the total flow rate of the styrene monomer to the first reactor, F ₂ is the total flow rate of the styrene monomer to the second reactor. Flow rate, V ₁ is the reactor content of the first reactor, V ₁ ′ is the content of the reaction liquid in the first reactor, V ₂ is the reactor content of the second reactor, and V ₂ ′ is the reaction in the second reactor. and information that the liquid point, V ₃ is the reactor and the contents of the third reactor, V ₃ 'is cut out contents to the reaction solution points in the third reactor.

In the production method according to the present invention, the continuous bulk polymerization is carried out at 140 to 149 ° C. in the first reactor, the continuous bulk polymerization is carried out at 165 to 180 ° C. in the second reactor, and the continuous bulk polymerization in the third reactor is 190 to It is carried out at 205 ℃. The content of polystyrene obtained by the above method is 50 to 65% by weight in the second reactor, 70 to 85% by weight in the third reactor, the average molecular weight of the final pellet resin is 16 to 200,000, and fluidity 11-15, and yellowness is 1.0 or less.

Detailed Description of the Invention

Referring to the method of producing a high flow thermoplastic resin of the present invention in more detail.

First, in the first reactor and the second reactor, the styrene monomer is continuously supplied from the tank in which the styrene monomer is stored. Styrene monomers that can be used in the present invention include styrene; side chain alkyl-substituted styrenes such as α-ethylstyrene and α-methylstyrene; Nuclear alkyl substituted styrenes such as vinyl xylene, O-t-butylstyrene, P-t-butylstyrene and P-methyl styrene; Halogenated styrenes such as monochloro styrene, dichloro styrene, tribromo styrene and tetrahydro styrene; P-hydroxy styrene; And O-methoxy styrene. Of these, styrene is most commonly used.

(1) Polymerization in the first reactor

The total flow rate of the raw material solution (styrene monomer) to the first and second reactors is F, the total flow rate of the raw material solution to the first reactor is F ₁ , and the total flow rate of the raw material solution to the second reactor is F _2. , F = F ₁ + F ₂ , F = 12, 6.1 ≤ F ₁ / F ₂ ≤ 7.0 when the reactor volume of the first reactor is V ₁ , and the volume of the reaction solution in the first reactor is V ₁ ′. , Under the condition of 1.9 ≦ V ₁ / V ₁ ′ 2.9, continuously agitated polymerization at 140 to 149 ° C. by adjusting the stirrer speed of the first reactor to 30 times / minute.

In the case of F ₁ / F ₂ > 7.0, polystyrene of the appropriate molecular weight cannot be formed, and in the case of F ₁ / F ₂ <6.1, the viscosity of the reactant is too high, resulting in poor transport, making it difficult to control the temperature of the second reactor. However, a large amount of low molecular weight polystyrene is generated in the second reactor, so that a desired high flow resin cannot be obtained. In addition, the reason for maintaining the conditions of 6.1 ≦ F ₁ / F ₂ ≤ 7.0, F = F ₁ + F ₂ , F = 12 in the first reactor is to use the three reactors effectively to control the viscosity, It is to make it smooth and to make styrene resin of moderate molecular weight excellent in mold release property, and having high fluidity.

In the case of V ₁ / V ₁ '<1.9, the viscosity becomes too high and the load of the stirrer increases, which makes it difficult to operate and also poses a danger due to insufficient time to cope with an emergency situation. On the other hand, in the case of V ₁ / V ₁ '> 2.9, the solid content of the desired content cannot be obtained, and the molecular weight is lowered to obtain the desired resin.

As a result, by maintaining the reaction conditions in the first reactor, it is possible to smoothly transfer the reactants in the continuous bulk polymerization without using a solvent, thereby obtaining a high flow cationic resin having an average molecular weight of 16 to 200,000.

The polymerized product in the first reactor is continuously supplied to the second reactor and subjected to continuous bulk polymerization.

(2) Polymerization in Second Reactor

The total flow rate of the raw material solution (styrene monomer) to the first and second reactors is F, the total flow rate of the raw material solution to the first reactor is F ₁ , and the total flow rate of the raw material solution to the second reactor is F _2. When the content of the reactor in the second reactor is V ₂ , and the content of the reaction solution in the second reactor is V ₂ ′, the condition of 1.3 ≦ V ₂ / V ₂ ≦ 1.8 is maintained and the number of revolutions of the reactor is maintained. It is fixed at 20 times / min and subjected to continuous bulk polymerization at 165 to 180 deg. C so that the solid content is 50 to 65 wt%. In addition, 1.5 to 2.3% by weight of the hydrocarbon compound is continuously added to the final pellets.

Hydrocarbon compounds usable in the present invention are generally produced as white oil, which is produced in domestic Far East oil, unchanged petroleum, and the like, and LP-350, TOMI-350, and the like.

In the second reactor, in the case of V ₂ / V ₂ '> 1.8, the content of solid content is reduced, and productivity is decreased. In the case of V ₂ / V ₂ '<1.3, it is difficult to control the polymerization temperature due to the increase in calorific value.

Maintaining the temperature below 165 ° C. in the second reactor results in a decrease in productivity. Maintaining a temperature above 180 ° C. results in a low molecular weight formation rate in the final pellets, thereby preventing the desired high flow resin.

Therefore, the reaction conditions of the second reactor were maintained at 1.3 ≦ V ₂ / V ₂ ′ ≦ 1.8, F = F ₁ + F ₂ , F = 12, 165 to 180 ° C., and 1.5 to 2.3% by weight of the hydrocarbon compound was continuously The high flow polystyrene with excellent release property can be obtained by maintaining valuable productivity.

The polymerized product in the second reactor is continuously supplied to the third reactor and subjected to continuous bulk polymerization.

(3) polymerization in the third reactor

When the content of the reactor of the third reactor is V ₃ , and the content of the reaction solution in the third reactor is V ₃ ′, the condition of V ₃ / V ₃ '= 1 is maintained and the number of revolutions of the reactor is 15 times / It is fixed in minutes and subjected to continuous bulk polymerization at 190 to 205 ° C so that the solid content is 70 to 85% by weight.

Maintaining the temperature below 190 ° C. in the third reactor reduces the productivity, and it is not possible to obtain a solid content of the desired content. If the temperature is maintained above 205 ° C., the solid content increases, resulting in poor transport, and high molecular weight in the final pellet. The production rate is low to obtain the desired high flow resin.

Therefore, the reaction conditions of the third reactor is maintained at V ₃ / V ₃ '= 1, 190 ~ 205 ℃ to produce a polystyrene of the appropriate molecular weight that can have the desired fluidity, and increase the proportion of solid content, high flowability with excellent releasability Polystyrene of can be obtained.

Other additives such as molecular weight regulators may be added to the first reactor or the second reactor. For example, an antistatic agent, antioxidant, etc. can be added and used suitably according to each use.

After the polymerization reaction is completed in the third reactor, an unreacted monomer is separated through a temperature increaser, a volatilization tank, and the like, and is then cut into pellets. The average molecular weight of this pellet-form final resin is 16-200,000, fluidity is 11.0-15.0, and yellowness is 1.0 or less.

According to the production method of the present invention, polystyrene having good transparency and excellent releasability to maintain high flowability is efficiently manufactured using three reactors without additional solvent addition.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

Example 1

In the first reactor, the polymerization is carried out in which the total flow rate of the raw material solution (styrene monomer) into the first and second reactors is F, the total flow rate of the raw material solution into the first reactor is F ₁ , and the raw material solution is introduced into the second reactor. F = F ₁ + F ₂ , F = 12, F ₁ / when the total flow rate is F ₂ , the content of the reactor in the first reactor is V ₁ , and the content of the reaction solution in the first reactor is V ₁ ′. F ₂ = 6.5, V ₁ / V ₁ '= was carried out under the reaction conditions of 2.7. Continuous block polymerization was performed at the stirrer speed of 30 times / min and polymerization temperature of 145 degreeC.

The polymer of the first reactor is continuously supplied to the second reactor in the same manner as the supply flow rate of the first reactor, so that the total flow rate of the raw material solution (styrene monomer) to the first and second reactors is F, and the raw material solution is the first reactor. The total flow rate introduced into the reactor F ₁ , the total flow rate of the raw material solution into the second reactor, F ₂ , the reactor volume of the second reactor V ₂ , and the volume of the reaction solution in the second reactor V ₂ ′. When V ₂ / V ₂ '= 1.5, F = F ₁ + F ₂ , F = 12 was maintained. The rotation speed of the reactor was fixed at 20 times / minute, and the reaction temperature was maintained at 170 ° C.

In the second reactor, white oil, a hydrocarbon compound extracted from petroleum, was continuously added in a separate storage tank so as to be 1.5% by weight in the final pellet.

The polymer of the second reactor was continuously fed to the third reactor. When the reactor content of the third reactor was V ₃ and the content of the reaction solution in the third reactor was V ₃ ', V ₃ / V ₃ ' = 1 The condition of was maintained, the rotation speed of the reactor was fixed at 15 times / min, the reaction temperature was maintained at 195 ℃.

The final polymer obtained in the third reactor was continuously sent to a devolatilization step and heated up to 245 ° C. to remove volatile components such as unreacted monomers. Molecular weight, yellowness, and fluidity were measured about the obtained resin on pellets, and mold release property was evaluated using the lattice mold of the injection machine.

Flowability was measured by ASTM D1238 (200 ° C., 5 kg).

Yellowness was measured by JIS K7105.

Molecular weight is 5 mg of the sample in the final pellet, 5 ml of THF is mixed in a shaker and shaken for 30 minutes to completely dissolve the solution, and then the solution is subjected to gel permeation chromatography of SPECTRA-PHYSICS ANALYTICAL. Measured.

The release cracking rate was calculated by converting 20 crack generation rates into a 5.3 OZ injection machine manufactured by Venus Cable using a lattice mold for evaluation of release property.

Example 2

F ₁ / F ₂ = 6.8 and was carried out in the same manner as in Example 1 except that the white oil continuously added to the second reactor was changed to 2.0% by weight.

Example 3

The residence time of the first reactor was adjusted to V ₁ / V ₁ ′ = 2.8, and the same procedure as in Example 1 was carried out except that the white oil continuously added to the second reactor was changed to 2.0 wt%.

Example 4

The same procedure as in Example 1 was carried out except that the residence time of the second reactor was adjusted to V ₂ / V ₂ ′ = 1.7.

Example 5

The same process as in Example 1 was conducted except that the temperature of the second reactor was changed to 177 ° C.

Example 6

The same process as in Example 1 was carried out except that the reaction temperature of the third reactor was changed to 198 ° C.

Example 7

The same procedure as in Example 1 was conducted except that the white oil continuously added to the second reactor was changed to 2.3 wt%.

Comparative Example 1

The reaction was carried out in the same manner as in Example 1 except that the reactor input ratio of the raw material solution (styrene monomer) was adjusted to F ₁ / F ₂ = 5.0.

Comparative Example 2

The same procedure as in Example 1 was carried out except that the residence time of the first reactor was adjusted to V ₁ / V ₁ ′ = 3.1.

Comparative Example 3

The same procedure as in Example 1 was conducted except that the residence time of the second reactor was adjusted to V ₂ / V ₂ ′ = 2.2.

Comparative Example 4

The same process as in Example 1 was conducted except that the temperature of the second reactor was changed to 185 ° C.

Comparative Example 5

The same process as in Example 1 was carried out except that the reaction temperature of the third reactor was changed to 208 ° C.

Comparative Example 6

The same process as in Example 1 was carried out except that the white oil was changed to 2.7 wt% in the second reactor.

Comparative Example 7

The same procedure as in Example 1 was conducted except that the white oil continuously added to the second reactor was adjusted to 3.0 wt%.

Tables 1 and 2 show the measurement results of the physical properties of the reaction conditions and the resins prepared according to the examples used in Examples 1 to 7 and Comparative Examples 1 to 7, respectively.

Example One 2 3 4 5 6 7 Reaction condition F = F ₁ + F ₂ 12 12 12 12 12 12 12 F ₁ / F ₂ 6.5 6.8 6.5 6.5 6.5 6.5 6.5 V ₁ / V ₁ '' 2.7 2.7 2.8 2.7 2.7 2.7 2.7 V ₂ / V ₂ '' 1.5 1.5 1.5 1.7 1.5 1.5 1.5 V ₃ / V ₃ '' One One One One One One One Hydrocarbon compound (wt%) 1.5 2.0 2.0 1.5 1.5 1.5 2.3 Second reactor temperature (℃) 170 170 170 170 177 170 170 Third reactor temperature (℃) 195 195 195 195 195 198 195 Properties Average molecular weight (Mw x 1,000) 190 195 180 175 170 180 190 Yellow Degree (YI) 0.8 0.8 0.9 0.7 0.8 0.9 0.8 Fluidity (g / 10 min) 12.7 13.5 14.5 13.5 13.7 13.0 14.0 Release Breakage Rate (%) 2.0 1.5 2.1 2.5 2.3 2.2 1.7

Comparative Example One 2 3 4 5 6 7 Reaction condition F = F ₁ + F ₂ 12 12 12 12 12 12 12 F ₁ / F ₂ 5.0 6.5 6.5 6.5 6.5 6.5 6.5 V ₁ / V ₁ '' 2.7 3.1 2.7 2.7 2.7 2.7 2.7 V ₂ / V ₂ '' 1.5 1.5 2.2 1.5 1.5 1.5 1.5 V ₃ / V ₃ '' One One One One One One One Hydrocarbon compound (wt%) 1.5 1.5 1.5 1.5 1.5 2.7 3.0 Second reactor temperature (℃) 170 170 170 185 170 170 170 Third reactor temperature (℃) 195 195 195 195 208 195 195 Properties Average molecular weight (Mw x 1,000) 140 145 147 150 151 150 148 Yellow Degree (YI) 0.9 0.8 0.8 1.0 1.3 0.8 0.9 Fluidity (g / 10 min) 16.6 16.4 16.3 16.3 16.2 17.2 17.5 Release Breakage Rate (%) 5.2 5.0 5.0 4.5 4.2 4.4 4.8

From the results of Tables 1 and 2, it can be seen that polystyrene resin having excellent yellowness, mold release property and fluidity can be obtained by continuous bulk polymerization under the reaction conditions according to the present invention.

The present invention has the effect of providing a high-flow thermoplastic resin, which is useful for the production of food and beverage containers, audio product cases, refrigerator internal parts, general merchandise containers, etc., as well as good yellowness and excellent fluidity. .

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (4)

Styrene monomer is the first and the second reactor total flow rate of F, the raw material solution to the total flow rate fed to the first reactor, F _{1, the} raw material solution, the entire flow rate of the F _2, the first reactor being fed to the second reactor is fed to the F = F ₁ + F ₂ , F = 12, 6.1 ≤ F ₁ / F ₂ ≤ 7.0, 1.9 ≤ V when the reactor content of V ₁ , the content of the reaction solution in the first reactor is V ₁ ' Continuous bulk polymerization under the condition of ₁ / V ₁ ≦≦ 2.9; When the content of the reactor in the second reactor is V ₂ and the content of the reaction solution in the second reactor is V ₂ ′, 1.3 ≤ V ₂ / V ₂ '≤ 1.8, F = F ₁ + F ₂ Continuous bulk polymerization under the conditions of and continuously adding 1.5 to 2.3% by weight of the hydrocarbon compound based on the final pellets; When the reactor volume of the third reactor in the third reactor is V ₃ and the volume of the reaction solution in the third reactor is V ₃ ′, continuous bulk polymerization is carried out under the condition of V ₃ / V ₃ '= 1; And Separating the unreacted monomer from the polymer produced from the third reactor and cutting into pellets; A method for producing a high flow thermoplastic resin having an average molecular weight of 16 to 200,000, a fluidity of 11.0 to 15.0, and a yellowness of 1.0 or less, characterized by being produced by the step. According to claim 1, wherein the temperature of the first reactor is maintained at 140 ~ 149 ℃, the temperature of the second reactor is maintained at 165 ~ 180 ℃, the temperature of the third reactor is maintained at 190 ~ 205 ℃ Method for producing a high flow thermoplastic resin, characterized in that. The method of claim 1, wherein the polystyrene solids content is 50 to 65 wt% in the second reactor, and the polystyrene solids content is 70 to 85 wt% in the third reactor. The method of manufacturing a high flow thermoplastic resin according to claim 1, wherein a molecular weight regulator, an antistatic agent or an antioxidant is further added to the first reactor or the second reactor.