JPS60147413A - Production of styrene based resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin, having improved transparency and heat resistance, and useful for industrial materials, etc. by easy operation, by polymerizing a monovinyl aromatic monomer with maleic anhydride while specifying the composition ratio of the respective copolymers in optional two stages by the continuous multistage polymerization method. CONSTITUTION:(A) A monovinyl aromatic monomer, e.g. styrene, is polymerized with (B) maleic anhydride to produce a styrene based resin by the continuous multistage polymerization method. In the process, the polymerization is carried out under such conditions that the composition ratio in the respective copolymers in optional two stages satisfies the formula (DELTAS1 is the amount of the monovinyl aromatic monomer polymerized per unit time in one stage; DELTAM1 is the amount of the maleic anhydride added per unit time in the stage; DELTAS2 is the amount of the monovinyl aromatic monomer polymerized per unit time in another stage; DELTAM2 is the amount of the maleic anhydride added per unit time in the stage) to give the aimed resin.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for producing a styrenic resin, and more specifically, to a method for producing a styrene-maleic anhydride copolymer with excellent transparency by a continuous multi-stage polymerization method. Regarding how to.

[Technical background of the invention and its problems]

Styrene-maleic anhydride copolymer has excellent transparency, heat resistance, high refractive index, excellent high-frequency insulation, and little strength loss at low temperatures, so it is used in various industrial materials, building materials, packaging materials, miscellaneous goods materials, etc. Applied.

This styrene-maleic anhydride copolymer is composed of styrene and its respective monomers, which are generally classified as monovinyl aromatic monomers.
It is manufactured by polymerizing M8 conductor and maleic anhydride.

As continuous polymerization methods in this case, single-stage continuous polymerization methods and multi-stage continuous polymerization methods are known.

The former is a polymerization method that proceeds in one reaction tank,
This method has the disadvantage that the conversion rate does not improve. In order to increase the conversion rate and transparency, a method has been adopted in which maleic anhydride corresponding to the amount of polymerized styrene is added to the quaternary reaction tank (Japanese Patent Application Laid-Open No. 58-1151).
No. 4).

However, this method is extremely complicated to operate and
Sushi cannot be called industrial.

The latter is a method in which multiple reaction vessels are arranged in series to proceed with polymerization, and is an industrially advantageous method. However, this method requires special reaction vessels and the entire process is complicated. The problem arises that it becomes iy.
No. 164110). Furthermore, Japanese Patent Publication No. 7849/1984 discloses a method in which maleic anhydride is added at a rate lower than the polymerization rate of styrene, but a transparent copolymer cannot be obtained by this method.

[Purpose of the invention]

The present invention aims to provide a method for producing a styrenic resin with excellent transparency and heat resistance using an ordinary reaction tank and a simple operation by applying an industrially advantageous continuous multi-stage polymerization method. do.

[Summary of the invention]

In order to achieve the above object, the present inventors have conducted extensive research on continuous multi-stage polymerization methods, and have discovered that styrene produced in each reaction tank in any two reaction stages.
We found that if the difference in the composition ratio of maleic anhydride in the maleic anhydride copolymer is controlled within a predetermined range, it is possible to produce the following resin with excellent transparency, which led us to develop the method of the present invention. Ta.

That is, the method for producing a styrenic resin of the present invention is a method for producing a styrenic resin from a monovinyl aromatic monomer and maleic anhydride by a continuous multi-stage polymerization method. The composition ratio of maleic anhydride of
M represents the amount of maleic anhydride added per unit time in this stage; ΔS2 represents the amount of monovinyl aromatic monomer polymerized per unit time in another stage, and 1M2 represents the amount of anhydride added per unit time in the other stage. It is characterized in that it satisfies the relationship expressed by:

' First, in the method of the present invention, a plurality of polymerization tanks are arranged in series, and a monovinyl aromatic derivative, which will be described later, and a copolymer, which has been polymerized to some extent in the previous stage, are sequentially flowed into each tank at a constant flow rate. Then, at each stage, a predetermined amount of maleic anhydride is added.

In this continuous multi-stage polymerization, the number of polymerization tanks installed may be two or three stages. Providing a greater number of stages may not be inconvenient, but there is no industrial advantage. Further, the polymerization tank used may be a normal polymerization tank, and a complete mixing type is preferable. The polymerization tank may be equipped with a double helical blade, Clochod-Russell blade, etc. as a stirring means.

Examples of the monovinyl aromatic monomer used as one of the raw materials include styrene, α-methylstyrene, dimethylstyrene, diethylstyrene, monochlorostyrene, diethylstyrene, vinyltoluene, or appropriate mixtures thereof. . In particular, styrene, α-
Methylstyrene and vinyltoluene are preferred.

Polymerization may be carried out by either bulk polymerization or solution polymerization. Industrially, it is preferable to carry out bulk polymerization, which does not require recovery and separation of the solvent.

The polymerization may be carried out either thermally or in the presence of a catalyst. In the latter case, the catalyst used may be any catalyst used in normal radical polymerization, such as benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, cumene hydroperoxide, diisoprobyl benzene hydroperoxide, diisoprobyl peroxydicarbonate, t-butyl peroxybenzoate, t-butyl peroxide/hybarate, Stearoyl peroxide, azobisisobutyronitrile, 1,1-bis(t-butylperoxy)-
3,3,5-trimethylzoclohexane, 1. l-bis(t-butylperoxy)cyclohexane, 2,2-bis(t-phthylperoxy)octane, n-butyl-
4,4-bis(t-glyveroxine valerate, 2
,2-bis(t]ethylperoxy)butane, di-t-
Mention may be made of butylshiba-oxyisophthalate and 2,5-dimethyl-2,5-di(be/'shibaoxy)hexane.

When using a solvent, for example, be/zene, toluene,
Chrysanthemum, ethylbenzene, methyl ethyl ketone, acetone, tetrahydrofuran, dioxane, dimethylformamide, chlorobenzene.

Inglobil alcohol, n-butyl alcohol,
Just use it.

Polymerization is carried out at a temperature of 70-200°C, preferably 80-160°C. Additionally, it is useful to add butadiene rubber, styrene/-butadiene rubber, imprene rubber, butadiene/-acrylonitrile rubber, etc. to the reaction system during the first polymerization to improve the impact resistance of the resulting styrene-maleic anhydride copolymer. .

A feature of the present invention is that in the continuous multi-stage superposition carried out as described above, any two reaction stages are managed so as to satisfy the relationship described below.

In other words, the amount of monovinyl aromatic monomer polymerized per unit time in a certain stage polymerization tank is determined by ΔS1 (for example, mol/
hr ), and the amount of maleic anhydride added to the polymerization tank per unit time is -ΔMs (for example, mol/h
r) and 17, and also in one other polymerization tank, the polymerization amount per unit time of heptanovinyl aromatic, 1 $ polymer is ΔS2 (e.g. mol/hr), and the unit time of maleic anhydride to be nitrated is rtf] is 3M2.

ΔMt/Δ8. +ΔMI or ΔM2/Δs2+ΔM2
Both mean the reaction amount of maleic anhydride with respect to the total N@ amount j of the copolymer produced in one polymerization tank. Another 1
This represents the composition ratio of maleic anhydride in the copolymer.

Therefore, what is the difference (absolute value) between the two in each copolymer in the two polymerization tanks? maleic anhydride.

This is the difference in the composition ratio of

The present invention manages this difference to 0.045 or less as described above. When this value exceeds 0.045, the transparency of the obtained copolymer deteriorates.

Preferably it is 0.04 or less.

In order to manage the above value to 0.045 or less, a method, for example, of increasing the temperature of the denomination is applied.

[Embodiments of the invention]

Examples 1 to 7 A reactor with a capacity of 2.31 mm equipped with a stirrer with double helical blades was used as the first polymerization tank, and a reactor with a capacity of 2.01 cm equipped with a stirrer with Clofford-Russell blades was used as the second polymerization tank. , these are arranged in series.

Styrene and maleic anhydride (molten maleic anhydride) were supplied to the first polymerization tank at the indicated flow rates.

The polymerization vessel was maintained at the indicated temperature.

From the lower part of the first polymerization tank, the partially polymerized mixture of copolymer □ and styrene is continuously fed into the second polymerization tank, and at the indicated flow rate there, maleic anhydride (molten maleic anhydride 1r 1 polymerization tank was maintained at the indicated temperature.

Reaction mixture sound taken out from the second polymerization tank 200'C, 3
After treatment under 0 mHH conditions to remove the reactive monomer, the obtained copolymer was made into a plate with a thickness of 3 m. The total light transmittance of the resulting film was measured.

Examples 8 and 9 Reactors No. 2 and 01 equipped with Clophod Miracel A stirrers were installed as third polymerization tanks downstream of the second polymerization tanks of Examples 1 to 7. Polymerization was carried out under the conditions shown in the table, and a plate having a thickness of 3 cm was also produced. The total light transmittance of the plate material was measured and the results are shown in the table.

The operating conditions and total light transmittance results for each of the above examples are collectively shown in the table.

〔Effect of the invention〕

As is clear from the above description, one method of the present invention is as follows.

Although it is a continuous multi-stage method, it is possible to produce a styrene-maleic anhydride copolymer tS with excellent transparency using one ordinary polymerization tank and simple operations. In addition, the obtained copolymer is not only transparent but also has good heat resistance, so it is useful for various yuzu industrial materials, building materials, packaging materials, and miscellaneous goods materials.

Procedural amendment November 30, 1980 Director of Patent W Gakudono Shiga ■, Indication of the case 1982 Patent Application No. 1368 2, Name of the invention Method for manufacturing styrenic resin 3, Person making the amendment Relationship to the case Patent applicant name Idemitsu Petrochemical Co., Ltd. 4, Agent 5° Date of amendment order Voluntary T 6, Subject of amendment Detailed explanation of the invention in the specification column 7, Contents of amendment (1) Specification page 3 1 In the second line, "In order to increase the conversion rate and transparency," should be amended to "In order to increase the conversion rate and transparency," should be changed to "such a method."

(2) No. 3 of the specification: Lines 9 to 12 of ``This is an advantageous method, but this method requires a special reaction tank.'' issue)
. ” is an advantageous method.
No. 184110 is available, but this method requires a special reaction tank and causes problems in that the overall process becomes more complicated. ” Procedural amendment January 11, 1985 Mr. Manabu Shiga, Commissioner of the Patent Office1, Indication of the case Patent Application No. 1368 of 19822, Name of the invention Process for manufacturing styrenic resin 3 , Relationship with the person making the amendment (41 cases) Name of patent applicant: Idemitsu Petrochemical Co., Ltd. 4, Agent 7, The detailed explanation of the invention column in the statement of contents of the amendment is amended as follows.

(1) "Polymerization means thermal polymerization or" in line 7 of page 6 of the specification is replaced with "the above bulk polymerization or solution polymerization means thermoelectric polymerization or"
and correct it.

(2) "Diisopropyl peroxydicarbonate" described in lines 15 and 16 of page 6 of the specification is corrected to "diisopropyl peroxydicarbonate."

(3) rt described in page 6, lines 17 and 18 of the specification
-butyloxyhyvalate" is corrected to "t-butylperoxypivalate."

(4) "rn-butyl-4,4-bis(t-butylperoxy)valerate" described in lines 3 and 4 of page 7 of the specification is replaced by "n-butyl-4,4-bis(t- butyl peroxy) valerate”.

(5) “ΔM□/ΔS, +ΔMi or 6M2 /ΔS2+ΔM” described on page 8, line 17 of the specification
2J as “ΔM□/(Δs, +ΔM+) or 6M2/(
ΔS2+ΔM2)".

(6) Add the following sentence to the next line of page 11, line 2 of the specification.

"Comparative Examples 1 to 3 As a comparative example, 1ΔM1/(ΔS1+ΔM1)-6M2/
The thickness was 3 under the same conditions as Examples 1 to 9 except that the value of (ΔS2+ΔM2)1 was set to exceed 0.045.
■The board was manufactured. The total light transmittance of the plate material was measured in the same manner as in the examples, and the results are also shown in the table. (7) Note: The catalyst described on page 12 of the specification is 1
, i(bis-tert-butylperoxy)-1,3
, 5-trimethylcyclohexane was used. ” to “Note)
As a catalyst, 1. L-(bis-tert-butylperoxy)-3,3,5-trimethylcyclo-hexane was used. ” he corrected.

Claims (1)

[Claims] In a method for producing a styrenic resin from a monovinyl aromatic monomer and maleic anhydride by a continuous multi-stage polymerization method, the composition ratio of maleic anhydride in each copolymer in any two stages is the following formula 2 (where ΔSl represents the amount of monovinyl aromatic monomer polymerized per unit time in one stage, and ΔMN represents the amount of maleic anhydride added per unit time in that stage; ΔS2 represents the amount of monovinyl aromatic monomer polymerized per unit time in another stage, and 3M2 represents the amount of maleic anhydride added per unit time in that stage. Characteristic manufacturing method of styrenic resin.