JPS60190406A - Improved stopping and reopening method for radical group polymerization - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A6 The minute hand of the present invention The present invention uses vinyl monomers (one or two The present invention relates to a method for producing a polymer by free radical polymerization. More particularly, the present invention relates to stopping and restarting such polymerizations without producing substandard polymers. The term "off-spec" polymerization 14 refers to a polymer that has properties, such as specific viscosity, that are significantly different from the standard polymer. The term "significantly different" refers to a difference in, for example, its dyeability or frequency of fiber formation, which adversely affects the usefulness of the polymer.

B. Description of the Prior Art Methods for the free radical polymerization of vinyl monolayers (1 or 241 or more) using the redox-based catalysts are well known in the art, such as acrylonitrile and one or two
There is the production of acrylic yarn polymers by aqueous fractional polymerization with more than one vinyl monomer.

Commercially, this process involves the continuous introduction of co-feed materials (monomers, redox catalyst components, water, etc.) into a reactor that is stirred and dispersed. The acrylic spinning wheel combines a 1-1 flow of water containing unreacted monomers and catalyst components from the reactor into a conduit that disposes the contents of the 1-1 reactor each time near the top of the reactor. This is done by making it flow and taking it out altwise. An auxiliary agent is added to the JIN outlet stream to stop the combination reaction for a short time, making it possible to recover unreacted single carriers. The redox catalyst system that can be used in this method consists of a detonator and a cytepersul 7ate ion (=s2
o8), bisulfate ion\in ζ(H
8O3) and iron ions (Fe ++ and Fe ++ ) as promoters. Reactions involved when using such threads include the following reactions: fl) "5208 + Fe" →= so4 +-5
o4 + Fe”10(21H8O3+Fe”” −+
H8O3+Fe”(31H8O3+ M −+ H80
3M(41ISO3MQ +M −+ H3O3M20
, etc. (5) -804+ M-+-804M+61
504M+M-)-8 4M2, etc. (in each formula, M represents a vinyl monomer and Mo represents a vinyl monomer group). Iron ions act simultaneously as an oxidizing agent (1) and as a reducing agent (2), reducing the vinyl olfactory content by polymerization (3).
) and (4), as well as (5) and (6). Normal commercial methods for halting or stopping this method are required! ,+−,−i,
For example, it is a simple method to shut down all co-feed to the reactor when a mechanical failure occurs or when preventive control is required. The process is restarted by the simple procedure of reintroducing the feedstock into the im' fabric, vessel 1, and .6. This stop-and-restart method results in a large amount of off-spec polymer produced when the polymerization is stopped and then restarted again. Separation of off-spec polymers from zero-spec polymers with dyeing properties that cannot be removed is an expensive and time-consuming operation.As an alternative, upon restarting the process, the The aqueous stream is discarded until all the polymer is again within specifications.

SUMMARY OF THE INVENTION According to the present invention, the termination of free radical polymerization of vinyl monomers (one or more monomers) using a redox catalyst system containing a promoter, a reducing agent, and an oxidizing agent consisting of polyvalent metal ions. and how to resume. The method of the invention includes the steps of (a) adding sufficient chelating agent to chelate the metal ions present as a promoter; and (b) adding enough chelating agent to chelate the metal ions present as a promoter; Add the monomer (1 yuzu or 21i14 or more) in a liquid that ensures that the mer groups polymerize to produce an in-spec polymer, and then (c) add the chelating agent present in step 11. Polymerization is restarted by adding the polyvalent metal compound or metal at a level sufficient to provide mW of accelerator corresponding to the concentration previously used.

Step a The chelating agent added in step (a) reacts with the metal ions present as a promoter and incorporates the metal ions.
W Generate 1-4 structures. In this chelated form, the metal ion can no longer function as an oil enhancer for the catalyst and the polymerization is stopped. The monomer added in step (b) ensures that the monolithic particles already present at the time the chelating agent is added will polymerize to form an on-spec polymer. The molecular weight (MW) of a polymer is proportional to the concentration of monomer groups (CM) present, and is proportional to the concentration of monomer groups (MO) present.
), i.e. MW' - (M)/(
Mo).

Upon restarting the polymerization, the metal compound or metal is added in an amount sufficient to provide a metal ion concentration that substantially corresponds to the concentration that existed before the chelating agent was added.

Preferred Embodiments of the Invention The stopping/resuming method of the present invention uses vinyl monomers (1 yuzu or 2 yuzu).
species) can be used in any batch or continuous free radical binding process using redox catalyst threads containing polyvalent gold as the reducing agent, oxidizing agent and promoter.

Alternative oxidizing agents include peroxide, bar carbonate,
Includes barborates, chlorates, purged sulfates and versulfates such as hydrogen peroxide or sodium or ammonium persulfate. Typical reducing agents include bisulfites, sulfates, and sulfinic acids, such as sodium bisulfite, sodium meta-M sulfite, sodium bisulfite, sodium thiosulfate, dialkyl sulfites, and oxidizable sulfoxy acids such as sulfinic acids. Compounds included.

Alternative polyvalent metal ions include ions such as iron, vanadium, indium, thorium, scandium, gallium, titanium, nickel, copper, cobalt, chromium, and the like. Kanetsuna is a water-soluble salt in the form of one yuzu, for example, Fe3.
It is convenient to add it to the aqueous medium in the form of O3.

To carry out step 1 of the method of the invention (a), a chelating agent can be added to the polymerization mixture to chelate the metal ions. Representative chelating inhibitors include ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaphosphoric acid (DTPA), trilotriacetic acid (NTA), and N-hydroxyethylethylenediaminetriacetic acid (HEDTA). Sufficient chelating agent is added to chelate the polyvalent metal ions present. Usually, a slight excess of the amount expected to chelate all of the metal ions present is added. Once the chelating agent is added and the genus ion is chelated, polymerization of the monomer groups already present continues even if no further monomer groups are produced. Unless additional monomers are added to the polymerization mixture along with the chelating agent, these monomer groups already present will polymerize to form a low molecular weight off-spec polymer. 803 and So per polymer III
, as groups, increasing the concentration of terminal So, 8 and 804 groups increases the polymer molecule 11. i will decrease, which will change the dyeing properties of the polymer.

To carry out step (b) of the method of the invention, a sufficient amount of Add monomer to the polymerization mixture. Which AA t should be added to achieve this result? To carry out step 4(c) of Ming's method, the polyvalent gold (-4 ion) can be easily determined by the chelating agent. Polymerization of the monomers is restarted by adding sufficient h to provide substantially the same concentration of metal ions as the ion concentration. In this way, the reaction returns immediately and an on-spec polymer is produced. If an excess of chelating agent is added to terminate the polymerization, the metal ion is added in excess of the original chelating agent, corresponding to the M required to react the excess chelating agent present. I have to.

The method of the present invention is particularly useful for stopping and restarting free radical polymerizations to produce acrylic yarn polymers from one or more vinyl monomers. As used herein, the term acrylic refers to a polymer having at least 5 acrylonitrile units (-0i(2-OH-)) in the polymer chain.
%, preferably in an amount of at least 85*1□1% (4%) of the long-chain synthetic copolymers containing -C1 and acrylonitrile copolymers. ft%H and one or more individual vinyl monomers copolymerizable with acrylonitrile, such as vinyl acetate, acrylic methyl,
It is produced by subjecting methyl methacrylate, styrene vinyl chloride, vinylidene, vinyl bromide, etc., each containing 65 to 41% of OME i, to reaction.

The Takuma method can be used in combination with free radical polymerizations γ, 2, with or without diluents. It is convenient to use diluents such as water or dimethyl sulfoxide.

Next row is the invention? This will be explained further. In the example, life and death ('Nsp) is o,i,! per 1.0 deciliter of solvent in dimethylformamide. Measurements are made at 25°C with a ratio of l/I + 4 degrees.

EXAMPLE This example further illustrates the invention. In this example,
In this article, the method of the present invention is carried out using water, redundant catalyst components, monomers, a PI-(setting agent), and an accelerator under steady-state conditions maintained at 50°C and a PI of about 6°C. The acrylic fibers are continuously introduced into the reactor, which is stirred, and an aqueous stream containing the dispersed acrylic fibers, unreacted monomers, and catalyst components is placed near the top of the side of the reactor. It is used to stop and restart the free radical polymerization reaction, which is taken out of the reactor through an outlet.The following feed diagonal flow is introduced into the reactor: 1.2 at a flow rate of 1860 kl per hour. acrylonitrile (AN) and vinyl acetate (VA) in a weight l:ratio of parts (VA-) to 90.8 parts (AM) +2, FFI5O, in aqueous solution (source of metal ions); 6, water; 4, so2 Aqueous solution of; 5. NaHOO3(p) (modulator) and (NH4)2
Aqueous solution of S208.

Enough material is introduced into the reactor to provide an iron level of 0.4 ppm per unit type: approx.
．． S02 to (NH4)28208 ratio of 5 to 1; and water to monomer*weight ratio of approximately 6.5 to 1. Under these conditions, a copolymer of acrylonitrile and vinyl acetate having a specific viscosity of 0.155±0.01'J5
0 kg is produced per hour.

Polymerization is a raw material flow! 2.5. Stop (ie shut down) by stopping 4 and 5 and add 650 g of a 69% aqueous solution of sodium EjDTA diluted to 57857 with water to the reactor. The M of EiDTA is sufficient to chelate the iron ions present.

Single leg feed stream A1 continues to be introduced for an additional 6 minutes and then is stopped. The addition of this amount of monomer reduces the monomer groups present at the time of FiDTA addition to u, 155-f:fJ, 0
The ratio was determined in advance through experiments to be necessary for polymerization to a specific viscosity of 0.05.

After 15 tJ minutes, the reactor is restarted by adding FeSO4.7a2o15N dissolved in 3.785 liters of water, and then the feed stream is reintroduced to the bore.

Specific viscosity F against time! When F (Nsp) is drawn on a graph, the Nsp of Kura 7 for 9 U after adding the chelating inhibitor is 0.155 -), and the Nsp when polymerization restarts after 150 minutes is still the same. [J, 151].

For comparison purposes, the above-mentioned I4j Synthesis-1 (Experiment A) was carried out under identical conditions except for the following: In one of the experiments (Experiment C), the simple trt form of In another experiment (experiment D), λ is not added (all feed streams are stopped at rest);
Do not add EDTA while stopped, and add F”e80 when restarting.
No 4.7H30 is added; in the other experiment (experiment B), neither the unilobes nor EDTA are added at the time of stop or at the time of restart, and no FeSO4.7H20 is added at restart.

Table 1 summarizes these experimental specifications: 1. Actual additive material % EDTA monokt FeSO4 7M20A
Yes Yes Yes B No No No C Yes No Yes No Yes No The effect of stopping/resuming each experiment on the chassis body viscosity (Nsp) is shown in the third section.

Table 2 Dispersion experiment after stopping Stop+)lie 1 [J 30 6CJ Resuming 7 minutes A 1. '), 1550.1550.1550.155
, [], 151/150B (J, 1540.15(
J O, 1470, 1450, 145/150o O,
1560, 15411, 151 [J, 1460.145
/145D 0.155 [1,152[J, 149
0.146 0.144/150 The results in Table 2 show that the stop/restart method of the present study prevents the formation of off-spec polymers in five steps7. These results demonstrate the importance of adding monoclonal material during shutdown (compare Implementation A to Experiment 0).

Fruit dnO Tsumugi was prepared at the time of suspension (/C) without adding a chelating agent.
This shows that the addition of a monomer does not prevent the formation of substandard polymers.

Attorney Asahi Kaoru Procedural Amendment (spontaneous) dated July 7, 1980, to the Commissioner of the Japan Patent Office, 1, Indication of the case, Patent Application No. 41865, 1982, 2, Name of the invention: Improvement of free radical polymerization, termination of free radical polymerization, and Resumption method 3, relationship with the case of the person making the amendment Patent applicant address 4, agent number 6, number of inventions increased by the amendment 7, specification to be amended 8, content of amendment Details as attached Engraving of calligraphy (no change in content)

Claims (1)

[Scope of Claims] (1) 35% to 100% by weight of acrylonitrile and at least one vinyl filler copolymerizable therewith.
! A-vinyl AA 14 body containing 65% by weight to 0% by weight (
A method for stopping and restarting the free radical polymerization of one or more persimmons (a ) adding thereto sufficient chelating agent to chelate the multivalent metal ion to terminate the polymerization; (b) polymerizing the monomer groups present at the time the metal ion is chelated to form a chelate; adding the monomer to the chassis in sufficient quantity to ensure that it does not produce a polymer having a viscosity substantially corresponding to the specific viscosity of the polymer produced before adding the inhibitor; and (C) adding the polyvalent metal compound or metal to a sufficient amount of d to provide m1 of the accelerator that substantially corresponds to the degree of propagation of the accelerator present before the chelating agent is added. in,
A method that includes the step of restarting polymerization by adding (21) The method according to claim 1, in which the polymerization is carried out in the presence of a diluent. (3) The method according to claim 2, in which the diluent is water. (4) The polymerization is carried out in the presence of a monomer (1). Co-feeding raw materials containing seeds or two or more persimmons), redox catalyst components, and water are continuously introduced into a stirred reactor, and dispersed main coalescence and unreacted monomers (one persimmon or two or more persimmons) are continuously introduced into a stirred reactor. above) and by continuously withdrawing an aqueous stream containing the catalyst component, and the introduction of the feedstock into the reactor and the withdrawal of the aqueous stream from the reactor are carried out in step m (a) by introducing the chelating agent into the reactor. The method according to claim 6, which is stopped when the metal compound or gold 4 is added in step (0), and restarted when the metal compound or gold 4 is added. The method according to claim 4, which includes all of the vinyl monomers copolymerized if FIb. Claim 5 consisting of the group consisting of methyl methacrylate, styrene, vinyl chloride, vinylidene chloride and vinyl bromide.
Section method. (7) The method of claim 6, wherein the oxidizing agent is a peroxide, percarbonate, perforate, chlorate, purdisulfate, or persulfate. (8) The method according to claim 7, wherein the reducing agent is an oxidizable sulfoxy compound. (9) The method according to claim 8, wherein the sulfoxy compound is sulfur dioxide, bisulfite, sulfite, or sulfinic acid. (10) The method of Claim 9, wherein the sulfoxy compound is sodium bicarbonate (?Mm). The method of Claim 9, wherein the oxidant is θIl or persulfate. 03) The method of claim 11, wherein the polyvalent ion comprises iron ion. 04) The 77-method of claim 16, in which the vinyl monomer ta is acrylonitrile and acrylonitrile.