JPS58187410A - Production of aromatic vinyl compound and maleic anhydride copolymer - Google Patents

Abstract

PURPOSE:The copolymerization of an aromatic vinyl compound and maleic anhydride is effected as a polymeriation inhibitor or retarder is added to prevent the formation of scale, thus producing the titled copolymer containing a small amount of maleic anhydride randomly. CONSTITUTION:The polymerization is carried out as an aromatic vinyl compound such as styrene is continuously or intermittently added to maleic anhydride or its solution together with a polymerization inhibitor or retarder such as t-butylcatechol by 0.003-0.05wt% based on the above acid or its solution at 60-170 deg.C under stirring. Then, the unreacting monomers and volatile components are distilled off under reduced pressure to produce the objective copolymer containing 3-30wt% of maleic anhydride.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for producing a moldable aromatic saponyl-maleic anhydride-based composite having a maleic anhydride content of 3 to 30% by weight. The purpose of this invention is to provide an improved method for preventing the formation of scale in the production of so-called random copolymers in which maleic anhydride molecules are randomly distributed in polymer chains. be.

Polystyrene, acrylonitrile, butadiene-styrene copolymer! General styrene resins such as (^BS) have a good balance between moldability and mechanical strength, so they are used as molding materials in the light electrical field, industrial parts, V& These resins are used in various fields, but one thing they have in common is that they have a heat resistance temperature of 100°C.
Because of the major drawback of extremely low heat resistance, it has not been used in fields where heat resistance is required, and there is a strong desire to improve the heat resistance of this type of rotaryne resin.

In line with these demands, a method was proposed in which a small amount (3 to 30%) of maleic anhydride was copolymerized with an aromatic beer compound represented by styrene.
The heat resistance temperature has been improved to 0°C or higher, and the adhesion to inorganic materials such as glass fibers can also be improved.
It is expected that the range of applications will be greatly expanded by compensating for the shortcomings of conventional styrene resins.

However, as is well known, in this type of copolymerization reaction between an aromatic vinyl compound and maleic anhydride,
A so-called alternating copolymer in which both are bonded alternately with 1=1 is easily produced, and a random copolymer with a small amount of maleic anhydride, which is the object of the present invention, is easily produced. As described below, there are many problems and it is not technically easy to obtain this.

That is, for example, 90% by weight of styrene (hereinafter, St
It is sometimes abbreviated as. ) and 10% maleic anhydride (hereinafter sometimes abbreviated as HA) were charged into a polymerization tank and batch polymerization was carried out under heating and stirring, but at the beginning of the polymerization reaction, HA was about Although an alternating copolymer containing 50% by weight and approximately 50% by weight of St is produced, only a homopolymer of styrene is produced after I'lA disappears, so a copolymer with a uniform composition cannot be obtained. However, such resins are of inferior quality and cannot be used as molding materials.

By the way, to explain this copolymerization reaction theoretically, the ratio of the rate at which a polymer radical having a styrene radical at its end reacts with MA to the rate at which the radical reacts with styrene is defined as rl. , if the ratio of the rate at which a polymer radical having maleic anhydride radicals at the end reacts with A^ to the rate at which it reacts with styrene is r2, then as revealed by Mayo et al. The molar fraction l of i^ in the polymer mixture and H in the instantaneously generated copolymer
The following relationship holds true with the mole fraction y of A.

Here, the above reactivity ratios determined by Ding, Aifrey et al. are rl = o, o 42 r2-0 (J, Am, Ches, Soc, 67.2044
(+945)), when the usage rate of HA in the total amount of monomers is 10 mol%, the GA content in the single-shot copolymer is calculated to be 42 mol% from equation (1), and the alternating copolymer content is 42 mol%. It appears that it is close to merging.

Furthermore, the monomer composition to obtain a -^10 mol% polymer is similarly calculated to be 0.5 mol% from equation (1), which means that HA must be maintained at an extremely low concentration. For example, it is not possible to obtain a copolymer with a low h^ content of 3 to 30% by weight, which is suitable as a molding material, and therefore there is always a small amount of unreacted MA in the polymerization tank during the entire reaction time. It will become a science that the desired random copolymer can only be obtained by controlling the reaction system so that it exists.

In this way, the H^ content is relatively low, and this h^
When producing a copolymer suitable for an acid-form material in which is uniformly dispersed in the copolymer by a solution polymerization method or a bulk polymerization method, the consumption rate of 舛^ is lower than that of an aromatic vinyl compound. It is necessary to continuously or intermittently add A^ to the reaction system starting from a very large area, but US Patent No. 12971
No. 939 discloses this.

However, as a result of additional tests conducted by the present inventors, it has been found that the darning method also has some technical difficulties or drawbacks.

That is, according to the description in the same specification, a semi-batch polymerization experiment in which HA is continuously or intermittently supplied to the nail, and a multi-tank continuous polymerization experiment in which St, M, and A are continuously supplied to a polymerization tank equipped with an agitator. I tried polymerization experiments, but although I was able to obtain polymers that were satisfactory in terms of quality, in each case,
The adhesion of scale to the reaction tank walls and stirring blades was unavoidable.

Incidentally, such scale adhesion not only hinders the efficient removal of polymerization heat, but also increases in scale as the polymerization time passes, and in the worst case, it may fall into the reaction tank, causing, for example, In the continuous flow polymerization method, such falling deposits can cause serious operational troubles such as clogging piping and flow pumps during the process, and therefore the operation may be interrupted periodically or irregularly. However, since such scale is originally insoluble in solvents, mechanical removal is required, and the loss is serious. Become.

However, as a result of intensive research in view of the above-mentioned drawbacks of the prior art, the inventors of the present invention found that in addition to h^, which is continuously or intermittently supplied to the reaction tank, a polymerization inhibitor or polymerization inhibitor III Surprisingly, the present invention was completed by discovering scales that substantially prevented the occurrence of scales as described above.

That is, the present invention provides aromatic ginyl compounds such as St and vinyltoluene and other styrene derivatives+all
was heated to 60-17'O℃ with stirring, and the mixture was heated to 60-17'O ℃, -8 or its pronunciation) and this calendar^ or its solution (0 for bl).
．． 003 to 0.05% by weight of a polymerization inhibitor or inhibitor (C1) is polymerized while being continuously or intermittently supplied, and then unreacted monomers and volatile components are removed under reduced pressure. The present invention proposes a method for producing a moldable aromatic vinyl/maleic anhydride copolymer having an h^ content of 3 to 30% by weight.

Here, the polymerization inhibitor ICI is used to extend the induction period until the radical polymerization reaction between the aromatic vinyl compound 1a+ and hair starts, and on the other hand, the polymerization inhibitor tel Although there are techniques to reduce the rate of such polymerization reaction, it is preferable to use a polymerization inhibitor because it does not reduce the molecular weight of the produced polymer.

Typical polymerization inhibitors and CI are substances containing nitro, nitroso, quinoid, hydroxy, or amino groups, and among these, the most useful are hydroquinones and amine phenols, but above all t
-Butylcatechol (hereinafter abbreviated as τBC) is particularly effective.

Furthermore, these polymerization inhibitors or inhibitors (as a method of supplying C1 to the polymer solution, it may be mixed in advance with MA or a fake solution containing i) and then supplied to the polymer solution, or HA or its finished product is fake)
The amount of sedative (el) supplied may be within an optimal range depending on the structure of the polymerization reaction tank, polymerization conditions, etc., but MA or EL supplied throughout the reaction may be A suitable amount is 0.003 to 0.05% by weight based on the weight of the liquid. If the amount of these supplies is less than 0.003% by weight, the effect of preventing school from adhesion will not be recognized;
If it exceeds 0.5% by weight, the polymerization rate itself will be lowered, resulting in a decrease in the molecular weight of the desired copolymer and a deterioration in the hue, which is not preferable.

To explain this relationship more specifically, PIA is dissolved in the raw material St in which approximately 0.0012% of carbon dioxide is mixed as the polymerization inhibitor let, and this MA
- When the h^-St copolymer was produced using the -SL solution as the feed liquid, significant scale formation was observed (Comparative Example 1), but the new concentration compared to the 1'1A-5tl was added to give a concentration of 0.01% by weight, and this solution was used as a feed solution to produce an N, A-5L copolymer, and no scale was observed (Example 1).

As described above, it will be understood that the addition of the new polymerization inhibitor tel to the h^ supply liquid has a remarkable effect in preventing scale formation and adhesion to various devices.

On the other hand, $1 n31, which includes the above-mentioned Ga^, is this one)
ll? The aromatic vinyl compound iMl used as one of the monomers in carrying out the method of the present invention is a typical solvent. itself, or various other aromatic compounds, or esters, ketones, or organic halides, and the solution tb
Although the concentration of MA in 1 will vary depending on the type of solvent, the quality of the intended product, and the quality of the product, it is usually appropriate to set it at 5 to 30% by weight.

In addition, the aromatic vinyl compound (Chang) and cystyrene, α
- methylstyrene, chlorostyrene, dichlorostyrene, bromostyrene or vinyltoluene or a mixture thereof, but up to the 5 o'clock part of the compound ta+ is replaced by another vinyl compound copolymerizable with said MA(k)l; Typical such compounds include methyl (meth)acrylate, methacrylate, (meth)acrylonitrile, (meth)acrylamide, or methylol (meth)acrylamide.

Furthermore, the aS resistance of the copolymer obtained by the method of the present invention
For the purpose of improving sexuality, for example,
As disclosed in Japanese Patent No. 9, in the presence of a rubbery substance, the aromatic vinyl compound TJI as described above is
It goes without saying that impact-resistant resins may be obtained by copolymerizing various monomers such as 1 & rb) containing I and ^ or H^, and representative examples of such rubber-like materials include Typical examples include polybutadiene, a rubbery copolymer of butadiene and St, or a mixture thereof. It can be used by being pre-dissolved in a mixture with other copolymerizable vinyl compounds.

Incidentally, the invention described in Japanese Patent Publication No. 55-7849 mentioned above also involves the generation of scale due to the alternating copolymerization reaction of the aromatic vinyl compound and MA, but if the method of the present invention is followed. For example, even when such an impact-resistant resin is obtained, the problem of scale formation is easily solved.

Here, the above-mentioned polymer solution mainly refers to a solution containing the aromatic vinyl compound (Al and its polymer), and the aromatic vinyl compound/anhydrous maleic III-based copolymer which is the target product obtained by the method of the present invention. It should be used separately from.

To carry out the method of the invention, generally 60 to 170'C1
Preferably, the thermal polymerization reaction may be carried out at a temperature range of 70 to 140'C, and in this case, as a free radical-generating polymerization initiator, a peroxy or perazo compound soluble in the monomer, which is commonly known and commonly used, may be used. It is advantageous to accelerate the reaction wave by adding 0.001 to 1.0 weight percent of the total amount of monomers.

Thus, although it is still not clear why scale formation or adhesion is prevented by applying the method of the present invention,
When a polymerization inhibitor or inhibitor let is supplied to the polymer solution together with h^ or PIA solution (bl), some of the hydrogen that is formed before the supplied H^ is completely mixed with the reaction solution. It is thought that this is because polymerization is suppressed in areas with high H^ concentration, and as a result, various monomers to be subjected to polymerization or M
It is presumed that the production of copolymers or alternating copolymers with a high A content is suppressed, and as a result, scale adhesion within the reaction tank is prevented.

In carrying out the method of the present invention, it is also important to supply the polymerization inhibitor or inhibitor (Cl) after the viscosity of the polymer solution reaches a certain level, which is particularly effective in preventing scale formation. It is usually a SL with a weight average molecular weight (Mw) of 100,000 or more and can be shaped into an onion.
In the case of a -MA copolymer, it is preferable to feed the copolymer when its viscosity (measured by Pruck-Field measurement) reaches about 50 points or more.

To explain in more detail the relationship between such viscosity and the features of the method of the present invention, when carrying out the method of the present invention, the polymerization reaction proceeds in the same manner as in conventional solution polymerization or bulk polymerization reactions. As the polymer concentration in the tank increases, the viscosity also increases, and when producing a St-MA copolymer of about 9 m[1%], it is fed continuously or intermittently until the polymerization rate reaches about 40%. has a viscosity of 50 voids or less, so the MA solution pile (continuously or intermittently supplied) no longer contains polymerization inhibitor or inhibitor 1.
This MA solution can be mixed relatively easily without adding cI, that is, without applying the method of the present invention, and moreover, it is possible to mix the copolymerized solution without causing scale. It is also possible to obtain a combination.

However, this method of stopping the polymerization reaction with a low polymerization rate and removing unreacted monomers, solvents, and other volatile components under reduced pressure has extremely low productivity, and it is difficult to recover the volatile components. Since it is industrially disadvantageous due to the extra cost involved, it is desirable to carry out the polymerization reaction not only until the polymerization rate reaches 40 to 90%, but also until it reaches 90% or more. However, if this is done, the viscosity of the polymer solution in the polymerization tank will increase significantly, making it difficult to combine with the low-viscosity HA solution, resulting in alternating Am coalescence (only) in areas with high Ma concentration. On the other hand, there is a technical contradiction in that conventional methods tend to cause scale.

Therefore, if the method of the present invention is adopted in a region where the viscosity of the polymer solution is 50 poise or more, the effects of the method of the present invention as described above will be remarkable, and the generation or adhesion of scale can be prevented. In addition, the amount of polymerization inhibitor or inhibitor added can also be reduced.

Thus, the feature of the method of the present invention is that scale generation can be prevented without the need for any special or expensive equipment, and MA can be incorporated uniformly or randomly into the polymer chain. It is possible to obtain a molding resin with excellent island quality.

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples. In the following, % means overlapping %.

Example 1 Three polymerization tanks equipped with stirrers as shown in Figure 1 were arranged in series, and the reaction was carried out sequentially from the first polymerization tank to the second polymerization tank, and from the second polymerization tank to the third polymerization tank. The solution was allowed to flow, and MA and [-butylperoxy-2] were added to each reaction solution each time.
-Ethyl xanoate (hereinafter referred to as DBPfl)
It is abbreviated as ll. ) was used to increase the polymer concentration step by step, using a flow-type continuous polymerization device, in which the temperature in each polymerization tank was kept at 100℃, and the liquid volume in each polymerization tank was kept at 2.51℃ Ta. Further, in the first polymerization tank, a St solution containing both substances at a concentration of 5.2% H^, 0 TBC, and 25% OO was added at a rate of 552 g/hour, while TBPI! ! l of 1% toluene solution per hour
It was supplied at a rate of 1.5 g, and the i^ was 14%, toluene was 40%, and St was 46% as 1j sub-feed to the second polymerization tank.
% and TBC is 0. A 1% toluene solution of TBPEH (hereinafter abbreviated as [sub-supply Ill (]) J) was supplied at a rate of 116 g per hour, while a 1% toluene solution of TBPEH (hereinafter referred to as "sub-supply Ill (]) J") was supplied at a rate of 116 g/hour. It is abbreviated as supply liquid (2) 1.

) is fed at a rate of 19 g/hour, and the third polymerization tank is supplied with the same sub-feed liquids (1) and (2) as used in the second tank.
are supplied at a rate of 87g and 8g per hour, respectively,
Continuous polymerization was carried out over about 40 hours. At this time, the 1-s viscosity in the second polymerization tank is about 250 voids (Pluck-field method; the same applies hereinafter), and that in the third tank is about 8.
It was 00 boys.

After the reaction was completed, each polymerization tank was examined for the presence of insoluble polymer (scale), and no scale was observed at all.

The copolymer solution taken out from the third polymerization tank is transferred to a desolvation chamber, and unreacted upper and unreacted components are removed under reduced pressure to obtain the desired aromatic vinyl compound/maleic anhydride system. A copolymer was obtained.

Next, this was crushed and injection molded to prepare a test piece.

As a result of performing physical property tests on each of the test pieces, the tensile strength was 576 kHz/j and the Vicat softening temperature was 122°C.

Comparative Example 1 The first polymerization tank contained a styrene solution with an MAfi degree of 5.1% and TBP without any new addition of TBC.
56 toluene solutions with an Eil concentration of 1% each hour.
In proportions of 5 g and 22 g, the second and triple paddles contained sub-feed (1') as in Example 1, except that the fresh addition of DBC was omitted by one ψ, and sub-feed (2). However, the third tank was supplied at a rate of 146 g and 12 g per hour, and the third tank was supplied at a rate of 87 g and 5.5 g per hour, and the polymerization time was 12 hours. Repeat the same operation as in Example 1 except for changing
A copolymer for comparison was obtained.

In the case of this example, scale adhesion was observed immediately after the start of continuous polymerization, and the amount of adhesion gradually increased, and 12 hours after the start of polymerization, the scale was peeled off. Eventually, the pipe between the second tank and the third tank became clogged with scale, and finally the pipe became blocked and became stuck.

In addition, the liquid viscosity in the second tank in this example is approximately 550
It was about 2200 poise in the third tank.

The thus obtained copolymer was treated in the same manner as in Example 1 and subjected to the same physical property tests, and as a result, the tensile strength was 567.
The softening temperature in kg/ci was 118°C.

Example 2 Twenty-one reactors equipped with helical ribbon stirrers were equipped with S
694 g of t - 5.6 g of A and 0.0315 g of TBPE) I were charged, the rotation speed of the stirrer was set to 60 per minute, the temperature inside the reactor was maintained at 100°C, and H^ was 20%.
, an St solution with a concentration of 0.01% TBC (hereinafter referred to as solution (3)), and a St solution with a concentration of 1% TBPEH, TB
St solution with a concentration of 0.01% C (hereinafter referred to as (4
8 while continuously supplying liquid (referred to as ) at the following rate:
Allowed time to react. (3) The liquid supply rate was 63 g/hour at the beginning of the supply and gradually increased to 141 g/hour after 8 hours, while (4) the liquid supply rate was 4.4 g/hour at the start.
.

After 8 hours, the dose was gradually increased every hour to 6.6 g/hour.

As a result, the viscosity of the reaction solution 6 hours after the start of the reaction was approximately 100
The viscosity after 8 hours was about 1000 poise.

No insoluble scale was observed on the reactor or stirring blade after the reaction was completed.

The copolymer thus obtained had a substantially uniform composition and contained about 20% MA.

Comparative Example 2 In order to avoid adding any new TBC and to keep the polymerization rate and h^ content in the obtained copolymer at the same level as in Example 2, the supply rate of the (3') liquid was adjusted. was gradually increased hourly to 5.7 g/hour at the start of feeding and 106 g/hour after 8 hours, except that (4') 1 was kept at 5 g/hour throughout the entire reaction period. When the same procedure was carried out, approximately 2 g of insoluble scale was observed on the reactor and stirring blade after the reaction was completed.

The above liquids (3') and (4'') refer to liquids (3) and (4) of Example 2, respectively, in which TBC was omitted.

Example 3 The procedure was carried out in the same manner as in Example 2, except that 4-hydroxydiphenylamine of the same concentration was used in place of TBC in each of liquids (3) and (4). No insoluble scale was observed on any of the stirring blades.

Example 4 Be; First, [polybutadiene NF35J
(Asahi Kasei Kogyo 1w product) 50.2g, MA 4.
05g of BPEH, 0.03.75g of [-dodecylmercaptan], and 0.12g of butylated hydroxytoluene (88g) were dissolved in a helical ribbon type. Pour into an if separable flask with a stirrer, rotate the stirrer at 100 revolutions per minute, raise the temperature to 100°C, and the FIA is 17%, T
St solution c with a concentration of BC 0.02)6 or less, this is referred to as (5))) and a TBPEH concentration of 0.14%
While continuously adding a solution (hereinafter referred to as (6) solution) at the rate shown below, the reaction was carried out at the same temperature for 7 hours.

(5) The liquid addition rate is 52.8 per hour at the beginning of addition.
g, gradually increased hourly to 55.7 g/hour after 7 hours; on the other hand, that of (6) liquid was 26 g/hour at the beginning.
．． 1 g/hour, and after 7 hours, the dose was gradually decreased to 10.4 g/hour.

No insoluble scale was observed on the reactor or stirrer after the reaction was completed.

Comparative Example 3 (5) The same operation as in Example 4 was repeated except that the liquid was changed so that no new TBC was added.
As a result of observation after the reaction was completed, about 0.8g was added to the stirrer.
Insoluble scale was attached.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing an example of a fluidized continuous polymerization training used in carrying out the method of the present invention. In the figure, R4-----1st polymerization tank R2-----1st polymerization tank Ra'----13rd polymerization tank 'Pw,
P2 and p3---Pump S D------One theory Solvent device a---One Aromatic vinyl compound b------
Monomaleic anhydride or Is liquid containing it ---
---monopolymerization inhibitor or polymerization inhibitor v ---1-
~ Volatile matter patent applicant Dainippon Ink & Chemicals Co., Ltd. Figure pl,, F', ・P・

Claims (1)

[Claims] 1. Aromatic vinyl compound fat with 60-170
℃, and add O,
Polymerization is carried out while continuously or intermittently supplying OO3 to 0.05% polymerization inhibitor J corrector or polymerization inhibitor FCL, and then unreacted monomers and volatile components are removed under reduced pressure. The content of maleic anhydride is in the range of 3 to 301%, which is characterized by its removal! 11m method for producing li-shaped aromatic vinyl/maleic anhydride copolymer. 2. The method according to claim 1, characterized in that the aromatic vinyl compound (al is styrene). 3. The method according to claim 1, wherein the aromatic vinyl compound (al is characterized in that a1' is vinyltoluene) The method according to claim 1. 4. The method according to claim 1, wherein the aromatic vinyl compound tal is a styrene derivative. 5. The aromatic vinyl compound 1a. ) is a mixture of styrene and a styrene derivative.6 The aromatic vinyl compound ta+ is a mixture of styrene and vinyltoluene. Claim 1 is the method of Kishoku. 7. The method according to Claim 1, wherein the aromatic vinyl compound (5) # is a mixture of vinyltoluene and a styrene derivative. Method. 8. The aromatic vinyl compound (al is
2. The method according to claim 1, wherein up to 50% of the honey content of the maleic anhydride is replaced with a vinyl yarn thread copolymerizable with the maleic anhydride. 9. The aromatic vinyl compound (Jll is the compound (J
2. The method according to claim 1, wherein ll is obtained by fs-resolving polycitatsuene. 10. The aromatic vinyl compound fi1 is composed of the compound (a
The method according to claim 1, wherein a rubbery copolymer is dissolved in l. Il, the polymerization inhibitor or inhibitor (the supply of C1 is
2. The method of claim 1, wherein the process is started when the viscosity of the polymer solution during polymerization is about 50 poise or more. 12. The method according to claim 4.5 or 7, characterized in that the styrene derivative is α-methylstyrene. 13. Process h according to claim 4.5 or 7, characterized in that the styrene derivative is chlorostyrene. 14. The method 7) according to claim 14.5 or 7, wherein the styrene derivative is dichlorostyrene. 15. The method according to claim 4.5 or 7, wherein the styrene derivative is promostyrene. 16,11 Process according to claim 4.5 or 7, characterized in that the IE styrene derivative is dipromostyrene. 17. The method according to claim 8, wherein the m-th vinyl thread picker is methyl methacrylate. 1B. The method according to claim 118JJI, wherein the vinyl monomer is ethyl methacrylate. 19. Method d according to claim @II, item 8, characterized in that the ME vinyl yarn monomer is methyl acrylate. 20. The method according to claim 8, characterized in that the vinyl thread monomer M is ethyl acrylate-F. 21. The method according to claim 8, wherein the vinyl monomer is acrylonitrile. 22. The method according to claim 9, wherein the rubbery copolymer is a copolymer of butadiene and styrene.