DE1595668A1 - Process for the preparation of copolymers of trioxane - Google Patents

Description

FARBWERKE HOECHST AG, formerly Meister Lucius & Brüning file number: P 15 95 668.0-44 - Pw 5164

Date: December 8, 1969
. Dr.Eg/br

Process for the preparation of copolymers of trioxane

It is known that under the action of cationic catalysts with cyclic ethers which have at least adjacent carbon atoms in the ring, trioxane forms copolymers which are stable to alkaline degradation and which are valuable plastics due to their good mechanical and physical properties. However, copolymers of this type have the disadvantage that, apart from chemical stabilization reactions at the end of the polymer chain, they cannot be subsequently modified in the chain itself by chemical reactions. It is also known that trioxane can be copolymerized with bifunctional compounds, such as cyclohexene-1,2-oxide-4,4-dioxymethylene formal and β, Jjf-epoxypropoxy-β ¹ , / '- carbonatopropoxyalkanes. This results in polymers which either crosslink under the polymerization conditions or during subsequent tempering.

It has now been found that copolymers from 70 to 99.99 Percent by weight trioxane, 0.01 to 20 percent by weight of bifunctional compounds and 0 to 10 percent by weight cyclic ether advantageously prepared in the presence of cationic catalysts at temperatures from -50 to +110 C. can be, if one bifunctional compounds of the formula

R ₁ -R ₂ -CO-OR ₃

0 0 9 8 18/1619

j.i ün! ·?:!;,; ^ ;! : - ■ · ./. ;; /. ■, *. "-, u 3 cla-i Amendmentfles.v.4.9.19 ·

used, in the L a 2,3-epoxy-propyloxy or 1,3-dioxolano-4-methyloxy radical and R "is an aromatic hydrocarbon radical with 6 or 10 carbon atoms means

which is substituted by (A) and / or (B), where A is a χ y

Alkyl radical with 1 to 6 carbon atoms and B an alkoxy radical with 1 to 6 carbon atoms, χ is an integer from 0 to 4, y is an integer from 0 to 4 and χ + y is less than 5 and R _{0 is} an alkyl radical with 1 to Means 6 carbon atoms.

Suitable bifunctional compounds are, for example, p-glycidoxybenzoic acid methyl ester, Ethyl o-glycidoxybenzoate, methyl 3-methoxy-4-glycidoxybenzoate, methyl 3-methyl-6-glycidoxybenzoate or ethyl 2-glycidoxy-naphthalene-3-carboxylate.

In addition to trioxane and the bifunctional compounds cyclic ethers are used in amounts of 0 to 10 percent by weight, based on the total monomer mixture. Suitable cyclic Xthers are e.g. ethylene oxide, propylene oxide, epichlorohydrin, 1,4-butanediol formal, diethylene glycol formal, 1,4-butenediol formal, 1,4-butanediol diglycidyl ether, oxacyclobutane and 1,3-dioxolane.

The process according to the invention produces copolymers, in which the comonomer containing the ester group is incorporated into the molecular chain. The monomeric esters there is practically no regulator effect, so that high molecular weight products are obtained. So come out in Copolyraerisaten Trioxane, ethylene oxide and methyl p-glycidoxy-benzoate after whose alkaline? Treatment in benzyl alcohol at 150 ° C and then repeated boiling with methanol, the carbonyl band characteristic of the ester group in the IR spectrum of the polymer. For example, after quantitative evaluation of the IR spectrum of a copolymer from 100 Ge

00981 8/1619

parts by weight of trioxane, 2 parts by weight of ethylene oxide and 10 parts by weight of p-glycidoxybenzoic acid methyl ester, after its treatment, benzyl alcohol at 150 g and repeated boiling with methanol, 4.4% by weight of built-in p-glycidoxybenzoic acid ethyl ester can be detected. After treating these copolymers containing ester groups with bases, for example sodium hydroxide, barium hydroxide, calcium hydroxide or sodium methylate, the carbonyl band of the ester group disappears in the IR spectrum and the corresponding carboxylate band appears. For example, could be a polymer containing 4.4 percent by weight of the incorporated P-Glycidoxybenzoesäuremethylester, after treatment with sodium methylate benzylalkoholischer at 13O ⁰ C in such a are transferred, 3.7 weight percent of p-glycidoxybenzoesaures Natriumaalz contained installed.

The copolymers can be treated by subsequent treatment chemically change with agents that react with ester groups. For example, the ester groups in the polymer chain can be converted into amide groups with ammonia.

The cationic polymerization can be carried out by methods known per se in the melt, in solution or in suspension. Aliphatic or cycloaliphatic hydrocarbons having 5 to 18 carbon atoms, _z * B, which are inert towards the monomers and the catalyst, are used as solvents or suspending agents. η-hexane or cyclohexane, into consideration. However, preferably ⁰ C is polymerized in the melt at temperatures between +60 and -J-ILO.

To trigger the performed according to the method according to the invention Above all, Lewis acids (definition of Lewis acids: Kortüm, Lehrbuch der Elektrochemie, Wiesbaden 1948, pages 300 and 301) are particularly suitable for copolymerization Boron trifluoride. The latter is preferably in the form of his Complex compounds, e.g. as etherate, oxonium fluoroborate or substituted aryl azonium fluoroborate, used. The Concentrations

^{π Γι} 9 8 1 S, '"~ ι ^c

tration of the catalysts depends primarily on their Activity as a starter and can be between 0.0001 and 1.0 percent by weight, based on the total monomer mixture, be.

To remove the unstable hemiacetal end groups, the copolymers according to the invention can be used in a manner known per se alkaline degradation (as described in Belgian patent 617 897). Advantageously be light stabilizers and oxidation stabilizers added to the copolymers.

The copolymers produced by the process according to the invention are thermally stable and can be processed thermoplastically. You provide important raw materials Modification of polyacetals with reactive groups. They are preferably copolymers with ion groups processed.

example 1

A batch consisting of 1000 g of trioxane, 20 g of ethylene oxide and 30 g of p-glycidoxybenzoic acid methyl ester, was mixed with 20 ml BF "-dibutyl etherate (diluted to 1:40 with cyclohexane) as Catalyst added. The batch was polymerized in a closed vessel in a thermoconstant bath at 70.degree. The polymerization time was 60 minutes. The polymer block obtained was ground and removed to remove the unstable Hemiacetal end groups and the residual monomers in benzyl alcohol containing 1 percent by weight triethanolamine for 30 minutes treated at 150 C. After cooling, the polymer was filtered off with suction, boiled several times with methanol and kept at 50 to 70.degree dried in vacuum. The yield of polymer was 822 g.

0098 18/1619

The following values were measured on the polymer:

The reduced specific viscosity - ^ ₆₀ was 0.33 dl / g (50 mg of the polymer were dissolved in 10 ml of butyrolactone, which contained 2 percent diphenylamine, at 140 ° G, and the viscosity was measured at this temperature). The thermal stability at IC was 0.0164 percent per minute. (A sample of the polymer was stabilized with 0.7 percent by weight 2,2'-methylenebis (4-methyi ~ 6 - ». Tert-butylphenol) and 0.2 percent by weight dicyandiamide and subjected to thermal degradation for 45 minutes at a temperature of 230 ° C). . '

Example 2

Analogously to Example 1, 1000 g of Tfroxan, 20 g of ethylene oxide and 50 g of methyl p-glycidoxybenzoate were polymerized with 10 ml of BF ₃ -dibutyl etherate (1:40). The yield after alkaline degradation was 738 g.

The following was measured: KL => 0.0272 percent per minute

Melt index i _o = 3.7 g / 10 minutes (ASTM-D

* 1238-52 T)

Example 3

Analogously to Example 1, 100 g of trioxane, 2 g of ethylene oxide and 10 g of methyl p-glycidoxybenzoate with 3 ml of BFg dibutyl etherate (1:40) polymerized. The yield after alkaline degradation was 78 g.

The following was measured: % _{τ &} λ ^β 0 »40 dl / g.

0 0981 8/1619

Example 4

Analogously to Example 1, 100 g of trioxane, 2 g of ethylene oxide and 1 g of methyl o-glycidoxybenzoate with 1 ml of BFo-dibutyl etherate were added (1:40) polymerized. The yield after alkaline degradation was 76 g.

The following was measured: % _{x &} ^ ^ö 0.72 dl / g.
Example 5

Analogously to Example 1, 100 g of trioxane, 2 g of ethylene oxide and 2 g of methyl 3-methoxy-4-glycidoxy-benzoate were polymerized with 2 ml of BF ₃ -dibutyl etherate (1:40). The yield after alkaline degradation was 69 g.

The following was measured: ° t . - 0.49 dl / g.
Example 6

Analogously to Example 1, 100 g of "Eioxane, 2 g of ethylene oxide and 2 g of S-methyl-e-glycidoxy-benzoic acid methyl ester with 2 ml of B-fodibutyl etherate (1:40) polymerized. The yield after alkaline degradation was 72 g.

The following was measured: "I. = 0.41 dl / g.
Example 7

Analogously to Example 1, 100 g of trioxane, 2 g of ethylene oxide and 2 g of ethyl 2-glycidoxynaphthalene-3-carboxylate were _{polymerized with 2 ml of BF 3} -dibutyl etherate (1:40). The yield after alkaline degradation was 74 g.

Was eaten:. ι _red ^β 0.37 dl / g.

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Claims (1)

Claim: Process for the preparation of copolymers from 70 to 99.99 percent by weight of trioxane, 0.01 to 20 percent by weight of bifunctional compounds and 0 to 10 percent by weight of cyclic ethers in the presence of cationic catalysts at temperatures from -50 to +110 ⁰ C, characterized in that one bifunctional compounds of the formula - R ₂ - CO - 0 - used in which R _{1 is} a 2,3-epoxypropyloxy or 1,3-dioxolano-4-methyloxy radical and R "is an aromatic hydrocarbon radical with 6 or 10 carbon atoms, denoted by (A) and / or (B) is substituted, where A is a xy
Alkyl radical with 1 to 6 carbon atoms and B an alkoxy radical with 1 to 6 carbon atoms, χ is an integer from 0 to 4, y is an integer from 0 to 4 and χ + y is less than 5 and R _{3 is} an alkyl radical with 1 to 6 carbon atoms. means. 0 0981 87 1619