JPH06508875A - Benzene-free maleic anhydride/vinyl ether polymer - 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] Patent application related to benzene-free maleic anhydride/vinyl ether polymer cross reference This application is filed under pending U.S. Patent Application Serial No. 726.415, July 5, 1991. This application is a continuation of the original application, and will be inherited by the same successor.

In one concept, the present invention provides an inorganic material having a predetermined specific viscosity within the range of 1 to 5.5. A toxin-free copolymer of water maleic acid and an alkyl vinyl ether.

In another concept, the present invention provides maleic anhydride/methyl vinyl ether copolymer with a relatively high chain transfer reaction rate. It relates to a method that can be produced in the presence of a solvent having a certain constant. The present invention is In addition, a mixture of maleic anhydride and lower alkyl vinyl ether with high viscosity terpolymer.

Description of prior art Various processes for producing copolymers of maleic anhydride and lower alkyl vinyl ethers Commercial methods are available and these methods can be modified using different solvents and reaction conditions. A copolymer having a specific viscosity or molecular weight is obtained. Polymerization temperature, polymerization initiator adjusting the concentration of and/or the specific type of solvent used in the polymerization reaction. It is known that the molecular weight of copolymers can be partially controlled by . However, the purpose of the solvent used is to bind to the free radicals generated by the initiator and to It is generally believed that the purpose of this is to terminate the reaction quickly. In polymerization The degree of interference of a solvent can be determined from its chain transfer constant: Therefore, solvents with low chain transfer constants, such as benzene and chlorinated aliphatic Hydrocarbons exhibit relatively little tendency to inhibit chain reaction type polymerization.

On the other hand, solvents with significantly high chain transfer constants, such as toluene, xylene, Ethylbenzene exhibits a significantly higher degree of interference and chain termination in such polymerizations. It is thought that it causes a stop reaction. Therefore, for a given maleic anhydride For polymerization, solvents with low chain transfer constants, e.g. It produces a copolymer with a relatively high specific viscosity (high molecular weight), while a relatively high Solvents with chain transfer constants yield products with relatively low viscosities. .

To avoid the use of toxic benzene, various prior art methods employ other solvents. was attempted. For example, substitution with toluene, which has a relatively high chain transfer constant to dissolve the maleic anhydride monomer in the feedstock introduced into the reactor and initiate the reaction. contact with the comonomer in the liquid state to better distribute it in the vessel. let However, this method and similar methods are limited to numbers larger than about 50,000. It was not possible to obtain a copolymer product with a uniform molecular weight: therefore, the produced Maleic anhydride/vinyl ether copolymers have limited uses, such as adhesives, Not suitable for use as pastes, medical thickeners, etc.

It is therefore an object of the present invention to overcome the drawbacks of the above-mentioned methods and to Unique toxin-free maleic anhydride/low molecular weight The object of the present invention is to provide a class alkyl hinyl ether polymer.

The purpose of the pond of the present invention is to avoid interference with the polymerization reaction and to generate long polymer chains. We present a general method using solvents with high chain transfer constants for It is about providing.

Yet another object is to provide a benzene having an individually defined specific viscosity within the range of about 1 to about 5.5. To obtain a maleic anhydride/methyl vinyl ether copolymer that does not contain zene. Ru.

The purpose of the pond is to use solvents with the same high chain transfer constants between 1 and 5.5. The object of the present invention is to provide a general method for obtaining polymers having a predetermined specific viscosity within a range.

Still other objects of the invention include adhesives and food products and medicated creams, pastes, etc. toxin-free maleic anhydride/vinyl ether suitable for use in packaging such as The purpose is to obtain a copolymer.

These and other objects of the invention will be apparent from the following description and disclosure.

Description of the invention In the present invention, a toxin-free compound having a specific viscosity within the range of about 1.0 to 5.5 is used. In producing the hydromaleic acid/lower alkyl vinyl ether copolymer, (a ) In the reaction zone, lower alkyl-substituted benzene, liquid 06-C, alkane as a solvent are added. , saturated lower alkyl ethers or mixtures thereof, as well as auxiliary solvents. A controlled amount of lower alkyl vinyl ether or lower alkyl as described above as a solvent. Pre-charge a mixture of vinyl ether: (b) maleic anhydride monomer and excess of the lower alkyl vinyl ether monomer reactant outside the reaction zone. (c) the above monomers are mixed in advance at a temperature below the reaction temperature to form a polymerizable composite of the above monomers; The pre-mixed composite monomers are added to the pre-loaded reactor at a controlled feed rate. (d) the lower alkali is fed into the reaction zone over a long period of several hours; benzene or the above liquids C3-C, alkanes or mixtures thereof. (e) The complex monomer mixture is heated to a high concentration. Polymerization is carried out at high temperature and pressure, during which time the above complex is thoroughly mixed with an initiator solution into which it is gradually introduced. (f) forming a slurry of the polymer product in the solvent; (g) the polymerization; toxin-free, characterized in that the body is recovered from the above solvent as a product of the method. A method for producing a maleic anhydride/vinyl ether copolymer is provided. This method is It can be operated by a batch or continuous method and is clear from the disclosure below. .

Co-solvent systems suitable for use in the present method include those having relatively high chain transfer as a solvent. Lower alkyl-substituted aromatic compounds with dynamic reaction constants, e.g. toluene, xylene , individual compounds or mixtures such as ethylbenzene, liquids 06-C, alkanes, e.g. For example, heptane, cyclohexane, hexane, etc. and saturated lower alkyl ethers, For example, methyl t-butyl ether, diisopropyl ether, dibutyl ether , methyl butyl ether, etc., the same or different comonomer in the polymerization reaction. Lower alkyl vinyl ether Contains as a mixture with a co-solvent. Generally, the solvent pair in the pre-charged solvent mixture is The weight ratio of the co-solvent can range from about 4:1 to about 1:12 depending on the specific viscosity of the desired product. It can be changed between. The specific viscosity and molecular weight of the produced polymer depend on the solvent system. was found to vary directly with the amount of alkyl vinyl ether used in It was done. Thus, with a 4:1-1:1 solvent mixture, a viscosity of about 1 to about 3 On the other hand, a mixture of 1:1.4 to 1:12 forms a polymer of 5.5 Polymers with small viscosities are formed, which could not be achieved conventionally , 1,500,000 to 2,000,000.

In the above method, a suitable lower alkyl vinyl ether comonomer reactant is Ethyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether isobutyl vinyl ether, tert-butyl vinyl ether and methyl vinyl ether Contains ether: the latter is preferred.

At least a slight excess of lower alkyl vinyl relative to the maleic anhydride monomer The ether comonomer reactant is used in the premix zone. mole like this The ratio can vary from about 1:1 to about 2, or from about 1.3+1 to about 1.3+1. A molar ratio of 7+1 is preferred. maleic anhydride and vinyl ether monomer with low reactivity. Polymerization at appropriate temperatures and well premixed before entering the reactor to form polymer chains. The monomer-comonomer complex species is formed to provide an alternating polymeric product.

Mixing of the monomers is advantageously carried out at between about 30 and about 40°C and at atmospheric pressure.

The complex monomers are introduced into the reaction zone containing the pre-charged co-solvent mixture for about 2 to about 5 hours. for a period of time, preferably from about 2.5 to about 3.5 hours, or until the polymerization reaction reaches the desired level. be introduced gradually until the target is achieved. Generally, about 1:1.8 to about 1 = 3 parts/part Feed rate of monomer/comonomer complex versus cosolvent mixture or optimal mixing and temperature Use slightly higher or lower feed rates as recommended or required for temperature control. I can be there. Next, the polymerizable composite mixture is thoroughly stirred to give about 25 to about 10 Under a pressure of 0 pSig, a reaction temperature of about 45 to about 90°C was reached, while simultaneously is contacted with a free radical initiator that is continuously introduced into the reactor throughout the polymerization reaction.

Since free radical initiators are usually solid, they can be combined with lower alkyl-substituted benzenes or C ．． -C. Alkane, preferably the same aroma as used in the cosolvent mixture or alkane compounds, or mixtures thereof, before being introduced into the reactor. Understand. Preferred monomer mixture: maleic anhydride/methyl vinyl ether Recommended reaction temperatures and pressures for use in the 35 to about 70 psig. Ethyl, propyl and butyl vinyl ether co Monomers require slightly harsher reaction conditions within the above temperature and pressure ranges. .

Suitable free radical initiators are those known in the art and include peroxides, For example, benzoyl peroxide, lauryl peroxide, decanyl peroxide , tertiary butyl peroxyvivalate, tertiary amyl peroxyvivalate, etc. but is not limited to these. The initiator solution is mixed with the monomer mixture throughout the exothermic polymerization reaction. Continuously mix thoroughly. Concentration of initiator to maleic anhydride in the feed mixture The degree is generally about o.　oooos~about 0. 05: 1 part by weight, preferably about 0 ．． 0001 to about 0. 005 parts by weight.

In a reactor, the monomers are reacted under relatively mild reaction conditions and excess unreacted vinyl is removed. A portion of the solvent of the ether comonomer and cosolvent mixture is removed from the gaseous atmosphere during the exothermic reaction. Eliminate as olkuhe soto. Directly feed this overhead mixture into the reactor. Recirculate and mix with the co-solvent feed mixture, or alternatively separate the components and separate them. Can be recycled in any way.

After the addition of the complex monomer, initiator solution and co-solvent mixture is completed, the interior of the reactor is The container is held at the reaction temperature and pressure for an additional period of up to about 2 hours to remove the anhydrous maleic acid. Quantitative conversion of acid to the desired polymeric product can be ensured. of polymerization reaction At the end, add any additional solvent needed to add about 15 to A crude product mixture is provided containing approximately 30 by weight 96 solids. Next, process the slurry. The polymer product is recovered from the dilute solution in a nearly pure state.

Product recovery can be accomplished by any known method. One method is , comprising drying the crude product mixture under reduced pressure at a temperature above the boiling point of the solvent. this The solvent vaporized in the step is condensed and recycled as one of the feedstocks suitable for the reactor. I can do it.

An important advantage of this method is that contact with solvents and initiators with high chain transfer constants Limit the formation of polymeric chains by preforming the copolymerizable complex before This stems from the surprising discovery that the expected tendency of aromatic solvents is overcome. Also , continuous supply of initiator during the reaction minimizes the influence of aromatic solvent during the copolymerization reaction. Become small. Therefore, the only factor controlling the molecular weight of the product is an easily monitored , in the amount of vinyl ether solvent fed into the system. Here, a certain aromatic solvent, In other words, a solvent with a relatively high chain transfer reaction constant is do not terminate the reaction, but instead extend the chain, resulting in higher number average molecular weights, e.g. Approximately 1.00 o., which could not be achieved before. ooo ~ approx. 2,000, It has been found that it can be usefully used to produce products having a It was. Such products must be manufactured without trace amounts of these toxic components. adhesives, especially maleic anhydride/vinyl anhydride, including use as denture adhesives. The scope of application to nyl ether copolymers has been expanded. This high molecular weight copolymer is suitable for other New uses include food packaging or foraging in human skin, toothpaste additives, etc. It is used for cosolvent in the solvent mixture or lower alkyl in the comonomer complex When containing lower alkyl vinyl ethers that are not similar to vinyl ethers, dissimilar Co-solvents of alkyl vinyl ethers can also be reacted to produce high viscosities suitable for the above uses. Terpolymer products may be formed.

A more detailed description and best mode of implementation of the method of the invention is provided below in attached FIG. This is shown by the description. In an exemplary flowchart describing a batch operation, point 4381 alkyl vinyl ether (methyl vinyl ether) in a lamp equipped with a valve. 1367 bond into a high shear mixer at 25°C. 6, where it was introduced through line 4 with a valve. of maleic anhydride to form a composite comonomer. The remaining 3014 bottles The methyl vinyl ether feedstock from the supplemented by mixing with 3014 pounds of toluene entering via line 9 with A co-solvent mixture is provided, which is placed in a nitrogen purged reactor equipped with an effective mixing device 11. directly into the reactor 10. Toluene/methyl vinyl ether auxiliary solvent mixture After pre-charging the materials, the monomer to comonomer complex formed in the high shear mixer 6 is The coalescence is carried out at the first introduction into the reactor IO via line 12 equipped with a valve. at a feed rate effective to provide a weight ratio of the complex monomer to cosolvent mixture of about 1:2. supply Composite monomer (* Simultaneously with the introduction of the species, line 1 equipped with a valve is added to the reactor. Approximately 2.2 bonds of lauryl pel to 3010 bonds of toluene from 4 and 18 Charge the solution containing the oxide initiator. Composite monomer/comonomer species and gradually introducing the solution of the initiator into the sealed reactor IO over a period of about 2.5 hours; During this time, exothermic solution polymerization proceeds at about 65° C. and about 80 psig. during the reaction , the pressure exceeds the desired parts of vaporous unreacted methyl vinyl ether/toluene. - can be discharged as a head mixture into line 20 and then into condenser 22. The pressure is kept constant by means of a pressure regulating valve 44 adapted to vaporous unreacted methyl vinyl ether is removed via line 50, It can then be compressed and recovered. The remaining condensed methyl vinyl ether and The uncondensed toluene was recycled to reactor IO via line 24.

After completion of the polymerization reaction, the crude copolymer solids in toluene weigh approximately 18-25 96 of solids. This slurry is then pumped into the system with a valve. with toluene recovered from line 28 and supplied from line 30 equipped with a valve. Dilute with toluene with or without additional water. By post-dilution with toluene , the solids content in the crude product is reduced to about 15% by weight. Next, complete the pressure valve 44. fully opened to vaporize any remaining unreacted methyl vinyl ether via line 20. Remove. For most efficient operation, store the crude product using a holding tank (not shown). Can receive slurry and clean reactor lO for next feed batch . In the figure, the crude product is withdrawn from the reactor IO by line 36 and then reduced. It passes into a pressure dryer 38 where it is heated at a temperature of about 230°C and a vacuum of 28"Hg. solid methyl vinyl ether/free in quantitative yield and at least 99% purity. The water-maleic acid copolymer product is withdrawn and collected via line 40. Vacuum dryer 3 The toluene vaporized at 8 is removed via line 42 and passed to a cooling condenser 48. The top of the crude product slurry in reactor 10 is recycled to the process in line 28. After writing, feed for dilution.

From the description of FIG. 1 above, it can be seen that the process can be simplified by using other pressure reactors, It is clear that it can be applied to continuous operation. In addition, other alky Rubinyl ether comonomer can be used in place of methyl vinyl ether. and other aromatic or 06-C3 alkane solvents and other peroxide initiators Alternatively, the one described in FIG. 1 may be used without departing from the scope of the invention. and that any modifications, substitutions or variations of the methods described are also intended to be included herein. What you need to understandContinuation of the front page (81) Designated countries EP (AT, BE, CH, DE.

DK, ES, FR, GB, GR, IT, LU, MC, NL, SE), AU, CA , J.P. (72) Inventor: Coyle Laurie, New Chassis, United States of America 07040 Maplewood Lexington Avenue 65 (72) Inventor Taj Mohammed United States of America Georgia 30064 Marietsuta Bridle Run Tre Iru N W 3383 (72) Inventor: John A. Zamora, New Chassis, United States of America 07652 Paramus Heather Lane 52

Claims (1)

[Claims] 1. Benzene-free anhydrous Malay having a specific viscosity within the range of about 1.0 to 5.5 In producing the acid/lower alkyl vinyl ether polymer: (a) In a reactor, lower alkyl vinyl ether mixed with a lower alkyl vinyl ether co-solvent is added. Kill-substituted benzenes, saturated lower alkyl ethers and liquid C6-C8 alkanes, or a primary selected from the group consisting of individual compounds or mixtures of these. pre-charging a co-solvent mixture of solvents; (b) Maleic anhydride monomer and lower alkyl vinyl ether monomer are reacted. The above monomers are individually premixed in a molar ratio of about 1:1.1 to about 1:2 at temperatures below forming a polymerizable complex of; (c) adding the premixed The complex monomers are fed at a controlled feed rate over an extended period of several hours. ; (d) simultaneously introducing into said reactor a solution of a free radical initiator dissolved in a soluble amount of said solvent; and gradually introduce the initiator to maleic anhydride molar ratio of about 0.00005: 1 to about 0.05:1; (e) reacting the monomer mixture at high temperature and pressure; during which the monomers are thoroughly mixed with and continuously contacted with the initiator solution, throughout this period to ensure the polymerization reaction; (f) a slurry of the crude polymer product in the solvent; during which all unreacted vinyl ether is discharged from the reactor; ( g) recovering the polymer solid from the solvent as a product of the process; A benzene-free maleic anhydride/vinyl ether copolymer characterized by manufacturing method. 2. The above lower alkyl vinyl ether is methyl vinyl ether. The method according to claim 1. 3. Claims characterized in that the lower alkyl-substituted benzene is toluene. The method described in Box 2. 4. The polymerization reaction is carried out at a temperature of about 45 to about 90°C and about 25 to about 100 psig. 2. The method according to claim 1, wherein the method is carried out at 5. The polymerization reaction is carried out at a temperature of about 55 to about 75°C and about 35 to about 70 psig. 4. The method according to claim 3, characterized in that the method is carried out by: 6. Claim 1, wherein the solvent is lower alkyl-substituted benzene. Method described. 7. Weight ratio of lower alkyl substituted benzene to lower alkyl vinyl ether cosolvent 7. The method of claim 6, wherein the ratio is from about 4:1 to about 1:12. 8. Weight ratio of lower alkyl substituted benzene to lower alkyl vinyl ether cosolvent is about 4:1 to about 1:1, and the lower alkyl vinyl ether cosolvent is It is the same as the lower alkyl vinyl ether in the copolymerization, and the product is a copolymer. and the copolymer product has a specific viscosity of about 1 to 3. Method described. 9. Weight ratio of lower alkyl substituted benzene to lower alkyl vinyl ether cosolvent is about 1:1.4 to about 1:12, and the lower alkyl vinyl ether cosolvent is is the same as the lower alkyl vinyl ether in the polymer complex, and the product is copolymerized. and the copolymer product has a specific viscosity of about 3 to 5.5. The method described in Scope 6 of the request. 10. Step (b) is carried out in a high shear mixer at a temperature of about 30 to about 40°C. The method according to claim 1, characterized in that: 11. The feed rate of the monomer complex to the cosolvent mixture is about 1 part per part: A method according to claim 1, characterized in that the amount is from 1.8 to about 1:3 parts. 12. The above lower alkyl vinyl ethers are used as solvents and comonomers. methyl vinyl ether; when the above lower alkyl-substituted benzene is Yes; the weight ratio of toluene to methyl vinyl ether in the cosolvent mixture is approximately 1: 1.4 to about 1:12, and the reaction is carried out at a temperature of about 55 to about 70°C, about 35 to about 7 conducted at 0 psig and the polymer product has a specific viscosity of about 3 to about 5.5. The method according to claim 6, characterized in that: 13. Step (g) is carried out by drying the slurry of step (f) under reduced pressure to remove toluene. 13. The method of claim 12, wherein the method is carried out by: 14. A product produced by the method of claim 12. 15. Number average molecular weight greater than 1,000,000 and from about 3.0 to about 5.5 Methyl vinyl ether/maleic anhydride copolymer characterized by having specific viscosity body. 16. Step (a) comprises using a mixture of lower alkyl vinyl ethers as a co-solvent. and the product of the process is a terpolymer. The method described in Scope 1 of the request. 17. The above co-solvent is a mixture of methyl vinyl ether and butyl vinyl ether. , the comonomer in the complex is methyl vinyl ether, and the product is It is characterized by being a terpolymer of alkyl vinyl ether and maleic anhydride. 17. The method according to claim 16. 18. A product produced by the method of claim 16. 19. Step (a) comprises toluene, cyclohexane as the solvent in the co-solvent mixture. Claims characterized in that a mixture of the group consisting of xane and heptane is used The method described in 1. 20. Step (a) comprises a C6-C8 alkane as the solvent in the co-solvent mixture. The method according to claim 1, characterized in that the method uses: 21. Step (a) uses a saturated lower alkyl ether as the solvent. The method according to claim 1, characterized in that: 22. Claims characterized in that the solvent is methyl t-butyl ether. The method described in Box 21.