DE1174502B - Process for the production of soluble prepolymers of diallyl phthalate - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: C08f

German class: 39 c -25/01

Number: 1174 502

File number: H 46330IV d / 39 c

Filing date: July 10, 1962

Opening day: July 23, 1964

Diallyl phthalate prepolymers which still contain reactive double bonds are known and are used for the production of molding compounds, laminates, coatings and molded parts. To Common methods of partially polymerized diallyl phthalate is for most uses not very useful because on the one hand it still contains considerable amounts of the monomer, on the other hand, if the reaction is not stopped very early, crosslinked, not in many organic solvents has more soluble parts. The materials made from it tend due to this composition different shrinkage and are therefore susceptible to cracking and not dimensionally stable.

This disadvantage can be remedied by starting the polymerization after only a small amount of time Sales, namely before the formation of insoluble gel bodies, breaks off and the soluble ones from the mixture Prepolymers isolated. The yield of prepolymer in such a process is generally small amount.

It is known, the polymerization of diallyl phthalate in the presence of hydroquinone or Perform copper salts. This process delivers the prepolymer in higher yields, if required but careful cleaning of the product, as the additives mentioned in further processing the prepolymers have an unfavorable effect on the curing process, and phenolic inhibitors as well easily lead to discoloration.

It is also known to reduce the tendency towards the formation of insoluble by-products by that the polymerization of diallyl phthalate in carbon tetrachloride or in a mixture with allyl alcohol undertakes. However, one obtains either chlorine-containing products, which lead to discoloration Temperature exposure, especially when in contact with metals, tend, or in the second case, copolymers of diallyl phthalate with allyl alcohol, as these are incorporated into the macromolecule. This changes the properties of the finished products produced from the prepolymers obtained in this way - often changed in an undesirable way.

Finally, it is known to use benzyl alcohol or alkyl- or halogen-substituted benzyl alcohols or substituted benzyl chlorides as regulators for the production of solid diallyl phthalate prepolymers. However, these substances must be added in considerable amounts, preferably 10 and 25%, based on the monomer. These modifying agents are also partly incorporated into the macromolecule and consequently there are processes for the production of soluble ones
Prepolymers of diallyl phthalate

Applicant:

Henkel & Cie. G. m. B. H.,

Düsseldorf-Holthausen, Henkelstr. 67

Named as inventor:

Dr. Joachim Galinke, Düsseldorf-Holthausen - -

no pure prepolymers of diallyl phthalate obtained.

If polymerization regulators are added, all of the aforementioned processes also have the The disadvantage of a relatively long polymerization time, which can be up to 40 hours to be acceptable To obtain yields of diallyl phthalate prepolymer.

Finally, it is known to polymerize diallyl phthalate in the presence of thioglycolic acid. Included the polymerization is not carried out in suspension or in the presence of organic solvents. In this block polymerization, however, if any effect was observed, hardly any was observed Pushing out the gelling point determined. It could be due to the behavior of thioglycolic acid be assumed in the bulk polymerization that they are also in the polymerization in Suspension or in solvents would be similarly ineffective.

It has now been found that the disadvantages described can be eliminated and soluble prepolymers of diallyl phthalate can be obtained in a short time and with good yield by polymerization in aqueous suspension or in organic solvents using catalysts which form free radicals, if in the presence of 0.05 to 5 %, based on monomeric diallyl phthalate, of mercaptocarboxylic acids, the alkyl radicals of which contain 1 to 8 carbon atoms, or their salts, esters or amides polymerized.

409 637/4 «

The mercaptocarboxylic acids preferably contain 1 to 4 carbon atoms in the alkyl radical. The alkyl radicals can be straight-chain or branched. Particularly good results are achieved with thioglycolic acid. Suitable mercaptocarboxylic acids are also α- or ß-thiopropionic acid, the thiobutyric acids or the thiovaleric acids.

The salts of the mercaptocarboxylic acids mentioned include, for example, the alkali metal or ammonium salts in question. Suitable esters are esters of mercaptocarboxylic acids with alcohols up to 12 carbon atoms, short-chain alcohols, such as methanol, ethanol, propanol, butanol, are preferred. In the amides of the mercaptocarboxylic acids, the nitrogen can also carry 1 or 2 alkyl radicals, provided that these alkyl radicals contain no more than a total of 12 carbon atoms.

The amount of mercaptocarboxylic acid or its salt, ester or amide to be added is various Factors dependent, e.g. B. on the type of solvent, the concentration of the catalyst and the Diallyl phthalate. The optimal amount of the added mercaptocarboxylic acids or their derivatives can easily be determined by preliminary tests and is in the order of magnitude of 0.05 to 5%, based on on monomeric diallyl phthalate.

Known free-radical, in particular peroxidic, catalysts are used for the polymerization Initiators used, e.g. B. diacetyl peroxide, ditertiary butyl peroxide, dibenzoyl peroxide or tertiary butyl hydroperoxide. In general, their proportion is between 0.1 and 10%, based on the monomer content.

The polymerization is carried out in a manner known per se, preferably as a suspension polymerization in the aqueous phase or as solution polymerization in organic solvents. At the Working in aqueous suspension, the amount of water used can vary considerably, in general you will use 10 to 150% water, based on the monomer. In the case of suspension polymerization emulsifiers or dispersants, emulsion stabilizers and other known ones Additives are also used. In the case of polymerization in solution, it is expedient to use such organic solvents in which the monomer is readily soluble and the prepolymer is less soluble. Lower alcohols such as isopropanol, ethanol and methanol can be used as solvents. If appropriate, hydrocarbons and mixtures thereof with lower alcohols can also be used be used.

The polymerization is carried out at an elevated temperature, which is expediently between 50 ^° C. and the boiling point of the solvent. The reaction time is relatively short and is usually between 1 and 3 hours. Longer reaction times than 3 to 4 hours are not required.

The work-up of the reaction mixture depends on the polymerization method used. If a suspension polymerization has been carried out in the aqueous phase, this is separated into residual diallyl phthalate dissolved prepolymer in a known manner from the aqueous phase and carries the organic phase into a precipitation bath. To do this, a solvent is used that has the Monomers, but not the prepolymer dissolves, e.g. B. methanol. One can proceed in such a way that the organic phase poured into the precipitation bath with stirring, sprayed in or in a kneader with Precipitant is worked through. Sometimes it is advisable to use the solution at a moderately elevated temperature to dilute the prepolymer with inadequate amounts of precipitants for precipitation and then to add larger amounts of precipitants or the diluted solution in excess Pour in precipitant while stirring

ίο or to be injected. This way it will be free flowing and non-caking powders of the diallyl phthalate prepolymer obtain. If the desired free-flowing state is not yet fully achieved with the first precipitation, you can a reprecipitation, for example by dissolving the prepolymer in acetone and precipitating the same with Methanol, connect.

If the polymerization has been carried out in solution, it is often after the end of the polymerization part of the prepolymer has failed. You can precipitate further amounts by cooling or use the procedure described above.

The prepolymers of diallyl phthalate obtained by the process according to the invention can for the production of coatings, laminates and pressed parts are used.

example 1

184.5 ecm of water and 2.5 g of 80% strength thioglycolic acid were placed in a 500 ecm flask equipped with a reflux condenser, stirrer, dropping funnel and thermometer. After displacing the air with nitrogen, the mixture was heated to 100.degree. A mixture of 11.7 g of 85% strength dibenzoyl peroxide and 184.5 g of diallyl phthalate was allowed to run in over the course of 20 minutes with vigorous stirring. After the addition was complete, the mixture was stirred at 100 ^° C. for a further 1 hour (experiment a). The approach was repeated twice, but the duration of the subsequent stirring was 2 hours (experiment b) and 3 hours (experiment c).

The batches were then allowed to cool and separated after two layers had formed, the aqueous phase from the organic. The latter was diluted with 65 g of methanol and vigorously Stir sprayed into excess methanol. After complete mixing has occurred was, the polymer settled as a solid white powder. The methanolic solution that Contained unreacted monomer was filtered off with suction.

The yields of soluble prepolymer were, based on the diallyl phthalate used:

Experiment a) with a post-reaction time of 1 hour 31%, Test b) with a post-reaction time of 2 hours 37%, test c) with a post-reaction time of 3 hours 41%.

In all three cases the products obtained were clearly soluble in acetone.

Example 2

The approach described in Example 1 was repeated under the same reaction conditions, with the difference that different amounts of thioglycolic acid were used.

Yield of prepolymer in%, at a 2 hours 3 hours Thioglycolic acid based on monomer Response time (after the addition is complete) of 15th 16 (800 / oig) 1 hour 30th 38 era 13th 37 41 3.0 24 2.7 31 2.5

All products were clearly soluble in acetone.

Example 3

The approach described in Example 1 was repeated under the same conditions with the The difference is that both the amount of thioglycolic acid and benzoyl peroxide used vary became.

Benzoyl Yield of prepolymer in%, 2 hours 3 hours Thioglycol peroxide based on monomer, 37 41 acid (85% ® at a response time 28 37 (80%) G (after the addition is complete) of 28 36 G 11.70 1 hour 33 37 2.5 4.68 31 1.0 9.34 24 2.12 4.68 18th 0.94 29

Example 4

0.5 Yield of prepolymer in%, , at a 2 hours 3 hours 1.0 based on monomer Response time (after the addition is complete) of 41 42 relationship 1.5 1 hour 37 41 DAP on water 31 37 41 31 1 30th 1 1

Example 5

The approach according to Example 1 was repeated, with the difference that in the template from 184.5 ecm Water was added 1.85 g of an emulsifier, which by the addition of about 20 moles of ethylene oxide on 1 mole of nonylphenol was obtained. After the addition of the diallyl phthalate was complete Polymerized with further heating at 100 ° C for 3 hours. The work-up was carried out as in Example 1 described. 77.8 g of soluble prepolymer were obtained, corresponding to a yield of 42%.

Example 6

The apparatus described in Example 1 was initially charged with 184.5 ecm of water and 5 g of butyl thioglycolate. After heating to 100 ^° C

20th

25th

In the first two rows, the ratio of thioglycolic acid to benzoyl peroxide is 1: 5, calculated on pure substances, in the third row 1: 4.7 and in the last row 1: 5.3. all products were clearly soluble in acetone.

35

The approach according to Example 1 was repeated in the same way, the ratio of diallyl phthalate (DAP) was changed to water. The second row of the table corresponds to example 1. a mixture of 184.5 g of diallyl phthalate and 11.7 g of benzoyl peroxide (85%) was allowed to run in over the course of 20 minutes. After the addition is complete was polymerized for 4 hours at 100 ° C. with further stirring. The work-up was carried out as in Example 1 described, and gave 70.5 g of prepolymer, corresponding to a yield of 38%; it is clearly soluble in acetone.

Example 7

In the apparatus described in Example 1, 184.5 g of n-propanol were each made in four batches and 1 g of thioglycolic acid (80%) and heated to 95 to 99 ° C with vigorous stirring. In addition a mixture of 184.5 g each of diallyl phthalate was left with further stirring over the course of 20 minutes and 11.7 g of benzoyl peroxide (85%) run in. This was followed by further stirring and heating for 1 hour [experiment a], 2 hours [experiment b], 3 hours [experiment c] and 4 hours [Experiment d] polymerized further. The four different batches remained during the polymerization completely clear. After cooling, the prepolymer sat down together with monomeric diallyl phthalate as a highly viscous mass at the bottom of the vessel. It was withdrawn and stirred vigorously added dropwise into excess methanol as a precipitant. It has been taking different approaches obtain:

Experiment a) 59.2 g, corresponding to 32%,
Experiment b) 75.8 g, corresponding to 41%,
Experiment c) 77.8 g, corresponding to 42%,
Experiment d) 77.8 g, corresponding to 42%.

All products were clearly soluble in acetone.

The approaches of this example were repeated, with the difference that the amount of Thioglycolic acid (80%) was varied. Row 3 thus corresponds to the first approach in this example. The prepolymers obtained dissolve clearly in acetone.

45

55

6o

Thioglycol Yield of prepolymer in%, based on 2 hours 3 hours 4 hours acid on monomer, at a reaction time 24 (80%) (after the addition is complete) of 30th - G 1 hour 41 42 42 2.0 25th 40 44 * 45 * 1.5 29 1.0 32 0.5 31

Acetonic solution of the prepolymer slightly cloudy.
Example 8

A 500 ecm flask equipped with a reflux condenser, stirrer, dropping funnel and thermometer was charged with 184.5 ecm of water and 8.55 g of thioglycolic acid dodecyl ester. After displacing the air with nitrogen, was heated to 100 ⁰ C. A mixture of 11.7 g of 85% strength dibenzoyl peroxide and 184.5 g of diallyl phthalate was allowed to run in over the course of 20 minutes with vigorous stirring. After the addition was complete, the mixture was stirred at 100 ^° C. for a further 2 hours.

The polymerization batch was worked up as described in Example 1. The received The prepolymer dissolved clearly in acetone.

Example 9

In the apparatus described in Example 1, a mixture of 184.5 g of diallyl phthalate and 9.23 g of dibenzoyl peroxide was added dropwise (100 ° / oig) in a heated at 100 ⁰ C mixture of 184.5 cc water, and 4.4 g Thioglykolsäureäthanolamid. The addition took place within 20 minutes, and polymerization was carried out ^{at 95 to 100 ° C. in 3 hours.}

The work-up was carried out as described in Example 1, and a yield of 30% of prepolymer was obtained, which is clearly soluble in acetone was.

Example 10

In the manner described in Example 1 apparatus was placed in a heated at 100 ⁰ C mixture of 184.5 cc of water and 3.56 g a-mercaptopropionic acid with vigorous stirring a mixture of 184.5 g of diallyl phthalate and 9.23 g of dibenzoyl peroxide in 20 Dripped in minutes. Polymerization was then continued at 95 to 100 ° C. for 3 hours. After cooling and separating off the organic phase, 63.2 g of this

dissolved in acetone and precipitated by stirring into 900 ecm of methanol.

The yield, converted to the total batch, was 22% of theory of prepolymer, which in Acetone was clearly soluble.

Claims (1)

Claim: Process for the preparation of soluble prepolymers of diallyl phthalate by polymerization in aqueous suspension or in organic solvents using radical-forming Catalysts, characterized in that diallyl phthalate is used in the presence of 0.05 to 5%, based on monomeric diallyl phthalate, polymerized on mercaptocarboxylic acids, the alkyl radicals of which contain 1 to 8 carbon atoms, or their salts, esters or amides. Considered publications:
German Auslegeschrift No. 1,067,216;
U.S. Patent Nos. 2,446,314, 2,635,090; Journal of Polymer Science, 3 (1948), pp. 693 to 703. 409 637/442 7.64 0 Bundesdruckerei Berlin