DE1745161A1 - Process related to resins - Google Patents

Description

"Process in connection with resins" addendum to M 74 101 / IVd 39c This invention relates to methods relating to resins, more particularly to a new one Process for carrying out esterification reactions in alcohol groups containing Resins.

In the German patent application M 74 101 / IVd 39c, attorney files 16 193 a method is described in which a Polymer or Copolymer of an ester of its unsaturated alcohol under the action of a hydrolyzing one Means is subjected while the copolymer is in the molten state. It has now been found that esterification reactions are carried out on a resin while the resin is in a molten state.

Accordingly, the present invention encompasses a method in which a thermoplastic alcohol group-containing resin raw material, while it is in the molten state, subjected to the action of an esterifying agent whereby alcohol groups of the resin raw material are esterified.

An example of a method of the invention is to react an alcohol group-containing resin in a molten state with an acid anhydride. For example, the resin can be reacted with an anhydride of an acid which contains at least two carboxylic acid groups, according to the equation wherein the zigzag line represents part of the resin chain and R is a divalent radical which forms part of the anhydride.

The resin chain or the main skeleton of the starting material is usually unaffected by the reaction, although, as will be discussed, the appropriate selection of an esterifying agent a certain degree of crosslinking of the Resin chains favors which, if desired, can be effected.

The resin raw material is usually a synthetic resin. It can be, for example, a polyester or polyether derived from a triol, for example Glycerine comes from free alcoholic groups as side groups on the resin chain are present, but it has the structure of a polymer (although this Designation includes a copolymer) of an unsaturated alcohol.

The unsaturated alcohol is preferably aliphatic and can, for example Vinyl alcohol (term), a substituted vinyl alcohol, allyl alcohol, or crotyl alcohol be ; alternatively, a cyclic alcohol, for example 2-cyclohexan-1-ol or p-vinylbenzyl alcohol.

The resin raw material can be polymerized in appropriate cases a suitable unsaturated alcohol can be made, but this is not always possible, for example then when the unsaturated alcohol is the intended vinyl alcohol, and in such cases it is most simply the starting material by hydrolysis of a polymer of an ester of the unsaturated alcohol.

Suitable esters include, for example, those resulting from the combination of alcohols with an aliphatic monocarboxylic acid such as acetic acid, propionic acid, Butyric acid, caprylic acid or stearic acid or an aromatic monocarboxylic acid such as benzoic acid or toluolate are formed.

Such a hydrolysis reaction can be in solution in water or a inert solvent, for example an aromatic hydrocarbon such as Benzene or toluene. However, the preferred methods of manufacture are such hydrolyzed polymers in German patent applications M 74 101 / IVd 39 c and 23522/66 described, wherein the hydrolysis in solid or molten State is revealed.

The starting resin preferably has the structure of a copolymer of an unsaturated alcohol with another monomer, which is preferably an olefinic one Is a hydrocarbon and sometimes an olefin such as ethylene, propylene, 1-butene, Ieobutene or a higher homolog with either a straight or branched chain, for example 1-hexane or 2, 2, 4-trimethylpentene-1 can be. Two or more Olefins can be present in the resin if desired be. Farther the olefin hydrocarbon component may be or contain a cyclic olefin, such as cyclopentene or a compound with more than one olefinic bond, for example Butadiene, isoprene or 1,5-hexadiene; or an aryl olefin such as styrene. Ethylene is often the preferred olefinic hydrocarbon.

Other comonomers that can be used in the resin feedstock, if desired, may be present include, for example, a nitrile, such as acrylonitrile, or vinyl Vinylidene chloride, an ester of an unsaturated acid such as acrylic or Methacrylic acid, for example ethyl acrylate or methyl methacrylate, or very often an ester of an unsaturated alcohol such as vinyl acetate. In the latter The starting material can often suitably by partial hydrolysis of a case Polymer of the appropriate ester are prepared. For example, this can be The starting material can be a copolymer of AthurlenX vinyl acetate and vinyl alcohol.

The proportion of unsaturated alcohol in the starting resin with the Structure of a copolymer can, for example, up to 90% by weight, for example from 3 to 75% by weight and preferably from 5 to 50% by weight.

The esterifying agent can, for example, be an acid, an acid halide, be an acid anhydride or an @ster; in the latter case is the reaction is an interesterification. The esterifying agent can be inorganic or organic with some examples of inorganic esterifying agents being mineral acids such as sulfuric acid, hydrochloric acid, nitric acid and phosphoric acids; Acid halides such as sulfonyl chloride and anhydrides such as sulfur trioxide. Very often, however, the esterifying agent is organic, especially a carboxylic acid or a suitable derivative such as an acid halide or anhydride. It can be aliphatic or aromatic and where it is aliphatic it can be saturated or unsaturated. It can be inert Contain substituents such as a halogen or, if desired, a Alkoxy group. Examples of suitable organic esterifying agents include fatty acids such as formic, vinegar, propionic, butyric, caproic, lauric and stearic acids; unsaturated Carboxylic acids such as acrylic, methacrylic, crotonic and oleic acids; Halogen-containing aliphatic acids such as dichloroacetic acid; Dicarbon, Tricarbon and Polycarbonaliphatic Acids such as succinic, adipic, tricarballyl, maleic and fumaric acids; alicyclic Acids such as cyclohexanecarboxylic acid; aromatic acids such as benzoin, toluene, phthalic, Terephthalic, benzene-1, 2,4-tricarboxylic and phenylacetic acids and their ring-substituted ones Derivatives and the acid anhydrides, acid halides and lower alkyl esters of these Acids. (A lower alkyl ester is one in which the alkyl group is up to contains 4 carbon atoms).

Other organic esterifying agents include, for example, sulfonic acids such as benzenesulfonic acid and its acid halides.

Preferably the esterifying agent is an acid that is at least contains two carboxyl groups or their anhydride or acid halide. That esterified The product then contains acid groups and can be converted further with formation of derivative resins, especially for example with a base to form a resin, which contains salt groups and, as will be further explained, can be such further reaction with a base can be carried out simultaneously so that the salt group-containing Product is immediately isolated. It is preferred if an esterification of this Kind is carried out, an anhydride of such an acid as an esterifying agent use and a class of anhydrides found to be particularly useful includes such anhydrides derived from acids that separate two carboxy groups by a substituted or unsubstituted saturated or unsaturated chain of two or more carbon atoms, for example two or three carbon atoms contain. The chain can be straight or branched. Examples of suitable anhydrides of this class are amber; Glutar, adipine, maline, citracon, itacon, glutacon and Aconitic anhydrides and substituted derivatives of these anhydrides .. Another class very useful anhydrides include those anhydrides which are aromatic Dioarboxylic acids, such as, for example, phthalic and naphthalic anhydrides and their ring-substituted ones Alkyl, halo and alkoxy derivatives. An anhydride from a tricarboxylic or polycarboxylic acid can, if desired, be used, for example the anhydride of benzene-1, 2,4-tricarboxylic acid.

The process does not have to result in complete esterification of all hydroxyl groups lead in the resin feedstock; in many cases a partial esterification is for example up to 10% is sufficient. In any case, the esterifying agent must in a sufficiently stoichiometric ratio to the esterification of the resin in desired degree can be used, and very often it is preferable to use of an Uberechusee to work on esterifying agents. Such an excess # can, for example be about 10% or 20%.

If desired, a catalyst, especially an acidic or alkaline one, can be used reacting catalyst be present. Examples of suitable catalysts include Mineral acids such as sulfuric acid, alkali metal salts of weak acids such as sodium acetate or sodium carbonate, alkali metal hydroxides such as sodium hydroxide and amines such as, for example Pyridine.

Where the esterifying agent, for example a dicarboxylic acid or whose acid chloride or anhydride can be an alkaline conversion catalyst cause salt formation with carboxyl groups in the product; this can or may not be desirable, but such salt groups can be used where necessary to acidic carboxyl groups by the action of an acid such as sulfuric acid or hydrochloric acid. Where a catalyst is used it is preferred in an amount up to 5% by weight of the esterifying agent, for example from 0.1% up to 2% by weight present.

As stated earlier, the resin is in a molten state and the reaction temperature is therefore naturally higher than one at which the Resin melts. However, the temperature should not be high enough for the To cause disintegration of the resin and a temperature between 30 to 150 ° C higher than that at which the resin melts is often very suitable. The presence the esterification agent can soften the resin and therefore lower the Resin melting point, in some cases up to 30 ° C, below the usual value and this effect must be taken into account when selecting a suitable reaction temperature be asked. It has sometimes been found that a reaction temperature is above the resin melting point (as stated above) for working with relatively volatile esterification agents, such as a lower fatty acid, is unsuitable; in In such cases, the melting point can, if desired, by adding a suitable Plasticizer are lowered, which is preferably an organic liquid, the the resin under reaction conditions softens but does not dissolve (or not in a sufficient proportion is used to dissolve). Examples of such organic Liquids include such liquid hydrocarbons as, for example, the Petroleum fraction known as white spirit (mineral turpentine oil) or an aromatic one or naphthenic fraction such as benzene, toluene, xylene or cyclohexane.

The process can, in appropriate cases, be carried out at atmospheric pressure carried out, but it is often necessary to use increased pressure, evaporation of the esterifying agent or any organic used To prevent plasticizers. The reactant can be present as a gas or vapor be. Preferably the pressure is from 5 to 5000 psig (1.3 to 353 kg / cm2), for example from 500 to 2000 psig (36 to 142 kg / orn).

The process can be carried out as a batch or a continuous process will. It is often useful to start a batch reaction in a reaction vessel to cause it to be sealed off from the atmosphere and at a suitable temperature can be heated. Any stirring means are preferably provided and it is for example expedient to a Banbury or or another Use internal mixer as reaction vessel. A time from a few seconds to several minutes are normally required for the reaction to complete and, for example, a period of time is between 10 seconds and 30 minutes and very often between 25 seconds and 10 minutes usually sufficient. The reaction can continued until substantial equilibrium is reached or they can be stopped at an intermediate stage. At the end of the reaction, the pressure increases drained into the reaction kettle and removed the resin product. Any excess of esterifying agents, catalyst residues and plasticizers, provided these were used, if desired, by crushing the product and washing with a suitable liquid, for example water.

For a continuous process is the use of a continuous one Mixing machine like a Buss kneader or a screw extruder often particularly suitable, the esterifying agent either in the hopper of the machine introduced together with the resin raw material or separately into the interior of the Fixture especially at a point where some of the resin has already softened has taken place, be injected. The reaction then progresses to that extent like the mixture through the device is moved and at Appropriate adjustment of the advance ratio can reduce the dwell time chosen so that the response is up to the desired extent in time ends where the mixture reaches the mouthpiece of the device. A suitable one Nozzle can of course be attached to the extruder, with a special one Extrusion section is required. For example, a slide or a inflated film can be produced or a rod can be extruded which is subsequently cut into tablets. A water-cooling bath can then also be used used to wash the product. It is also possible to use a propellant, for example a gas or vapor, a volatile liquid or a substance, which gives rise to gas by thermal decomposition, so that the resin product is extruded in the form of a foam. A volatile hydrocarbon, for example Butane, is often a particularly useful propellant, and it can as well as plasticizers as described in the previous paragraph.

A nucleating agent such as a finely divided solid such as silica, if desired, may be present around the manufacture a large number of small cells to facilitate.

It is also possible to use a continuous process in the extruder a blow molding machine or in the Pre-plasticization section a screw preplasticizing injection molding machine so thatB molded objects are produced directly.

The resin products can be used in a wide variety of applications are dependent on the nature of the esterification groups and the extent to which the reaction takes place. For example, it reduces the esterification of the alcohol groups in a polyvinyl alcohol the water solubility and many by unsaturated Acid esterified resins are used to polymerize with unsaturated monomers Manufacture of thermosetting products suitable. A method of the latter Art is described, for example, in British Patent No. 968 463.

Where the esterifying agent is an acid with at least two carboxyl groups or the anhydride or acid halide thereof, the resin product contains acid groups or salt groups as explained above. Resin products with acid groups have special ones Value as intermediates in the manufacture of derivative resins. For example, can the acid groups by known methods of organic chemistry to salt, ester or Amide groups are converted, the properties characteristic of the derivative resin lend where the resin is reacted with a bifunctional substance, for example an oxide or hydroxide of a bi- or plain metal such as zinc oxide or a bi- or three-way Alcohol like ethylene glycol or glycerin or a Di- or polyamine such as, for example, ethylene diamine or phenylene diamine, is a Derivative resin made with crosslinks that give the same an increase in strength, Provide rigidity and resistance to elevated temperatures.

Monovalent ions can also produce weakly crosslinked products as a result let the ion fraction effect arise. A particularly useful type of networked Derivative resin is produced by reacting the acid group-containing resin with a resin containing alcoholic groups, for example a hydrolyzed one Copolymer of ethylene and vinyl acetate. A networked product can also get through Reacting the acid groups with the remaining hydroxyl groups of a partially esterified one Resin can be produced. Cross-linked products are often particularly foamed Shape useful and for example where an extruded foam can be made is to be carried out the crosslinking reaction so that it is in the extrusion cylinder takes place or takes place shortly after extrusion so that the foam structure is stabilized as a result of the increased stiffness of the crosslinked product. if desired, esterification and crosslinking reactions can be carried out in the same device, for example in an extrusion cylinder, or an esterification can take place in an extrusion press sbabbfiuden with a subsequent one forming the crosslinking Hartuugs stage.

It has been found that where the resin products contain salt groups, these are generally good in clarity, 2ah and strong, but none the less are easily processable according to the usual thermoplastic processing methods and accordingly in the manufacture of films and molded or extruded articles Find application.

The invention is illustrated by the following examples.

Example 1 This example describes the preparation of a resin with the structure of a copolymer of ethylene, vinyl alcohol, vinyl acetate and Monovinyl phthalate by reacting in the molten state with the phthalic anhydride a copolymer of ethylene, vinyl alcohol and vinyl acetate.

1000 g Har, which by the 90% hydrolysis of a copolymer of 87.5% by weight of ethylene and 12.5% by weight of vinyl acetate were obtained with 220 g powdered phthalic anhydride mixed trooken and the mixture through a annular die for making a strand with a diameter of 0.1 inch (2.54 mm) which was divided into tablets. The extruder used had an inner cylinder diameter of 1 inch (25.4 mm) that was throughput 17 g per minute, the residence time of the mixture in the cylinder about 1 minute and the cylinder temperature was 200 ° C.

The product was a tough white resin that contained carboxyl groups. By comparing its infrared absorption at 5.8 microns (CO absorption) with the at 6.8 microns (CH2 absorption) it was found to be due to the phthalic anhydride 54 to 57% was esterified, the ratio being the optical density of the product at 5.8 microns to that at 6.8 microns was 0.65. (A ratio of 1.68 will be obtained for a non-hydrolyzed copolymer of ethylene and vinyl acetate, while the ratio for the initially 90% hydrolyzed copolymer is only Q 17 was). The presence of hydroxyl groups in the partially esterified resin was determined indicated by a relatively broad and weak absorption at 2.9 microns, being the ratio of the optical density at that wavelength to that at 6.8 microns (the "OH / CH2 optical density ratio") was 0.12.

Part of the product was converted to its sodium salt by Dissolve the same in toluene at 85 ° C and pour the solution into a 0.1N solution of sodium hydroxide in methyl alcohol. The resin salt thereby became a white solid precipitated and filtered off. It had a relatively high melt viscosity, and so did it a clear, tough film could be obtained therefrom by pressing it between 2 polished steel plates at 180 ° C. It was in hot organic Insoluble in solvents, but was swollen by them.

Example 2 This example describes two methods of manufacture the sodium salt of a resin with the structure of a copolymer of ethylene, Vinyl alcohol, vinyl acetate and monovinyl phthalate by partial esterification, in molten State of a copolymer of ethylene, vinyl alcohol and vinyl acetate with phthalic anhydride in the presence of sodium acetate or sodium methoxide as alkaline reaction catalysts.

50 g of hydrolyzed ethylene / vinyl acetate copolymer, as in Example 1 were heat softened and over mill rolls at 150 ° C processed and 6.1g of anhydrous sodium acetate mixed into the resin. 11 g of phthalic anhydride were gradually introduced into the mixture and the temperature raised to 170 ° C for 15 minutes elevated. Acetic acid was evolved during the reaction.

The resulting resin was flexible and tough and in hot organic form Insoluble in solvents, although it was still thermoplastic. A part 1 became converted into its acid form by swelling it with toluene and reacting it with aqueous hydrochloric acid (15% HC1 based on the weight of the resin) and then through Pour the resulting solution into acidified methyl alcohol. The acid resin had a CO / CH2 optical density ratio of 0.85 and an OH / CH2 optical density ratio of 0.08, which shows that the phthalic anhydride has an approx 50% esterification had taken place.

In another experiment, the use of 37? g of 1N methanolic Sodium methoxide instead of sodium acetate causes a zigue esterification, whereby the CO / CH2 the optical density ratio of the acid resin was 0.

Example 3 This example describes the preparation of the sodium salt of a resin with the structure of a copolymer of ethylene, vinyl alcohol, vinyl acetate and monovinyl maleate by the partial esterification in the molten state of a copolymer of ethylene, vinyl alcohol and vinyl acetate with maleic anhydride in the presence of Sodium acetate as an alkaline reaction catalyst.

The procedure described in the first part of Example 2 was repeated, using 7.3 g of maleic anhydride instead of phthalic anhydride. The product was a very tough, insoluble resin with a high melt viscosity.

Part was made to its acid form as described in Example 2 and then had a CO / CH2 optical density ratio of 0.71 and a OH / CH2 optical density ratio of 0.08, indicating that a approximately 57% esterification by halic anhydride had taken place.

Example 4 This example describes further esterification processes according to the present invention.

The reaction procedures were similar to those used in Example 1 were described, with the reactants and the extrusion conditions are given in the table below. Except where otherwise stated the ratios of the reactants were 1 mole anhydride to 1 mole more alcoholic Groups in the parent resin.

Tabel esterification extrusion extrusion reaction mean temperature ratio (g / min.) degrees (° C) Phthalic Acid-170 10 20 anhydride 200 20 50 2307, 550 250 20 50 260 10 40 260+ 10+ 30+ Maleic acid-130 40 anhydride 160 8 35 170 9 50 170+ 9+ 25+ Serious Acid- 170 8 30 anhydride 192 8 40 270 6 @ ++ Notes: These experiments were carried out with 2 moles of anhydride per mole of alcoholic groups in the starting resin.

@ This product was crosslinked and not sufficiently soluble to determine the extent to which the reaction had occurred.

Except for the product @ ++, all resins produced were Similar to the product of Example 1, thermoplastic and essentially none networked. They could go to their respective Sodium salts the action of methanolic sodium hydroxide solution, as described in Example 1, being transformed. The salts were also essentially the same as the product of Example 1 similar.

Example 5 This example describes a method according to the invention for esterification with phthalic anhydride of a resin that has the structure of a copolymer of ethylene and vinyl alcohol and the conversion of the esterified product to a foamed crosslinked resin.

A mixture of phthalic anhydride and that used in Example 1 hydrolyzed xthylenevinylacetate copolymer was in the proportions 1 mol of anhydride to 2 moles of alcoholic groups in the copolymer, together with 2% finely divided Silicon dioxide (based on the weight of the copolymer) as the core-forming Plittel acts in an extrusion cylinder at a rate of 20 g per minute 1 inch (25.4 mm) in diameter. butas was in the extrusion cylinder injected at a rate of 5 g per minute, the cylinder temperature Was 150 ° C and the residence time was approximately 1 minute. The extrusion took place at 100 ° C through an annular nozzle with a 1/16 inch diameter, creating a foamed strand with a diameter of approximately 0, 2 inch was made.

It was found to be # 90% of the alcoholic groups of the starting resin were esterified and the product was insoluble in hot toluene, which indicated becomes that crosslinks are present. The foam had good rebound resilience and showed no tendency to collapse.

Claims (1)

P a t e n t a n s p r ü c h e: 1. Process for the esterification of alcoholic Groups of a thermoplastic resin raw material characterized in that exposed to the action of an esterifying agent in the molten state thereby esterifying the alcoholic groups of the resin. 2. The method according to claim 1, characterized in that the esterifying agent is an acid anhydride. 3. The method according to claim 2, characterized in that the anhydride that is an acid having at least two carboxyl groups. 4. The method according to any one of the preceding claims, characterized in that that the resin starting material has the structure of a polymer of an unsaturated Has alcohol. 5. The method according to claim 4, characterized in that the alcohol Is ethanol. 6. The method according to any one of claims 4 and 5, characterized in that that the resin starting material by hydrolysis of a polymer of an ester of the unsaturated alcohol. 7. The method according to claim 6, characterized in that # the ester Vinyl acetate is. 8. The method according to any one of claims 4 to 7, characterized in that since # the resin starting material is a copolymer of the unsaturated alcohol with a another monomer. 9. The method according to claim 8, characterized in that # the proportion unsaturated alcohol in the copolymer is 5 to 50 wt. 10. The method according to any one of claims 8 and 9, characterized in that that the other monomer is an olefinic hydrocarbon. 11. The method according to claim 10, characterized in that # the olefinic Hydrocarbon is ethylene. 12. The method according to claim 11, characterized in that # the resin starting material has the structure of a copolymer of ethylene, vinyl alcohol and vinyl acetate. 15. The method according to claim 12, characterized in that the resin starting material by partial hydrolysis of a copolymer of ethylene and vinyl acetate was produced. 14. The method according to any one of the preceding claims, characterized in that that the esterifying agent is an acid anhydride derived from an acid, which comprises two carboxyl groups substituted or unsubstituted by one saturated or unsaturated chain separated by two or more carbon atoms 15. The method according to claim 14, characterized in that the anhydride is succinic anhydride or maleic anhydride. 16. The method according to any one of claims 1 to 13, characterized in that that the esterifying agent is an anhydride of an aromatic dicarboxylic acid. 17. The method according to claim 16, characterized in that # the anhydride Is phthalic anhydride. 18. The method according to any one of the preceding claims, characterized in that that a partial esterification of the alcoholic groups takes place in the resin starting material. 19. The method according to any one of the preceding claims, characterized in that that a catalyst is present. 20. The method according to claim 19, characterized in that # the catalyst Is sodium acetate. 21. The method according to any one of the preceding claims, characterized in that because # the reaction temperature is between 30 and 150 ° C higher than the temperature, at which the resin melts. 22. The method according to one of the preceding claims, characterized in that because # it is carried out under increased pressure. 23. The method according to claim 22, characterized in that # the pressure from 500 to 2000 psig. amounts to. (36 to 142 kg / cm) 24. Method according to one of the preceding claims characterized in that # it is based on a batch process using a Internal mixer is carried out as a reaction pressure vessel. 25. The method according to claim 24, characterized in that # the reaction time between 25 seconds and 10 minutes. 26. The method according to one of claims 1 to 23, characterized in that because # it is done continuously. 27. The method according to claim 26, characterized in that a bus Ko-kneader or a screw extruder is used as the reaction pressure vessel. 28. The method according to claim 2? characterized in that the product in the form of a plate or blown film, or a rod, the following is cut into tablets. 29. The method according to claim 2? characterized in that a propellant is included so that the resin product is extruded in the form of a foam will. 30. The method according to claim 29, characterized in that the propellant is a volatile hydrocarbon. 31. The method according to any one of the preceding claims, characterized in that that a product is prepared which contains acid groups in turn with a base is reacted to form a resin containing salt groups. 32. The method according to claim 31, characterized in that the reaction is carried out with the base simultaneously with the esterification reaction so that the product containing salt groups is isolated in a direct manner. 33. The method according to claim 1 essentially as in one of the examples 1 to 3 described. 34. The method according to claim 1 essentially as in one of the examples 4 and 5. 35. Resin containing ester groups, which by a method according to any one of claims 1 to 33 was produced. 36. Resin containing ester groups, which by a method according to Claim 34 was made. 37. Resin according to claim 35, characterized in that it contains ester groups contains derived from an acid which has at least two carboxylic groups contains, so # the resin contains acid or salt groups. 38. Crosslinked derivative resin characterized in that it is by reacting a resin containing an acid group according to claim 37 with a resin containing contains alcoholic groups. 39. Crosslinked derivative resin characterized in that it is by reacting of the acid groups with the residual alcoholic groups of one containing acid groups partially esterified resin according to claim 37 is produced. 40. Networked Derivative resin like one of claims 38 and 39, characterized in that it has the form of a film, a sheet or plate or a foam. 41. Crosslinked derivative resin according to one of claims 38 to 40 thereby characterized because # it is derived from a resin according to claim 36,