DE1301099B - Process for the preparation of copolymers of trioxane - Google Patents

Description

1 2

It is known that high molecular weight poly a) 97.9 to 88.0 percent by weight of trioxane, merisate with repeating oxymethylene units

by polymerization of formaldehyde or by b) 2 to 10 percent by weight of a cyclic ether

May represent polymerization of trioxane. It is also known to the formula, by copolymerization of tri-5

oxane with saturated cyclic ethers, e.g. B. Glycol- ^ s

formal or ethylene oxide, thermally stable poly!

to produce acetals. Such products are pre- R ₁ CO

mainly used in the injection molding sector. It is | |

also known, copolymers of trioxane, eye- io R _a q (R ₁ ) ^

ical ethers and bifunctional compounds I

to manufacture. The previously known bifunctional η

However, compounds crosslink the copolymers ⁴ very easily and give infusible products.

It is also known to produce terpolymers of improved 15 in which R ₁ to R _{4 are} each hydrogen or alkyl flowability from trioxane, cyclic ethers and radicals or halogen-substituted alkyl radicals with alkyl glycidyl formals (cf. French 1 to 5 carbon atoms and R ₅ a methylene patent 1 376169). or oxymethylene radical, each alkyl or

The invention relates to a process for haloalkyl-substituted methylene or oxy-

Production of copolymers of trioxane by ao methylene radical, where η is an integer from 0 to 3

Polymerizing trioxane with cyclic ethers is, or the rest

and bifunctional compounds in the presence of . _nn . New

Catalysts at temperatures from -50 to + 100 ° C, - (.υ - CH ₂ - CH _a ) _m - UCH ₂ -

which is characterized in that one denotes mixtures, where η is 1 and m is a whole

of 35 is a number from 1 to 3, and

c) 0.1 to 3 percent by weight of a polyglycol diglycidyl ether of the formula

CH ₂ CH - CH ₂ - (O - CH ₂ - CH ₈ ) ,, - O - CH ₂ - CH CH ₂

Ό Ο

in which η is an integer from 2 to 5, boron fluoride and its complexes, e.g. B. boron trifluoride polymerized. The above-mentioned alkyl radicals etherate, very suitable. Particularly useful can be substituted with 0 to 3 halogen atoms, preferably those from Belgian patents 593,648 and weise chlorine atoms. 618 213 known diazonium fluoroborates and the

from the Belgian patent 585 980 known

Compounds are particularly suitable as cyclic ethers.

Ethylene oxide, glycol formal and diglycol formal. 40 The concentration of the catalysts can be adjusted in You can also z. B. Propylene oxide, Epichlor- wide limits vary. It is determined by use hydrin and 4-chloromethyldioxolane. the type of catalyst and the amount of

Polyglycol diglycidyl ethers of molecular weight which the polymer is supposed to have are particularly suitable. You of the formula given above, in which η is an integer between 0.0001 and 1 percent by weight, be number of 2 or 3. Preference is given to poly- 45 based on the monomer mixture, preferably glycol diglycidyl ether in amounts of 0.5 to 1.5 percent, and 0.001 to 0.1 percent by weight of catalyst, based on the total mixture of catalysts. Monomers used. Since the in the inventive method to

The copolymers are characterized by the fact that the catalysts used tend to decompose the polymer, which is substantially improved in the flowability of the polymers, and it is advisable to follow them directly afterwards melt out, a property that is specifically designed to render the polymerization ineffective, Production of large-area injection molded parts from z. B. with ammonia or with amine solutions. is crucial. The removal of unstable hemiacetal end groups

As in the case of other copolymers, the polymerization can be carried out by known methods according to the hitherto customary methods, ie in bulk, in solution or in a manner; the slurry is expediently in suspension. As the solvent, preference can indifferent at tempera, aliphatic and aromatic carbon doors of 100 to 200 ⁰ C of the polymer in aqueous ammonia, and also a swelling agent, hydrogen halides, halogenated hydrocarbons or ethers, such as methanol or n-propanol may be present, can be used. The poly- or the dissolution of the polymer in an alkaline merization in substance proceeds particularly smoothly. The polymerization is each 60-reacting medium at temperatures above 100 ⁰ C on the solvent used at -50 to + 10O ⁰ C followed by re-precipitation. Executed as a solution. medium are e.g. B. Benzyl alcohol, ethylene glycol mono-

The polymerization is initiated with ethyl ether known per se or a mixture of 60 ° / ₀ methanol and cationic catalysts. Suitable 40% water are suitable as alkaline reacting catalysts are e.g. B. Inorganic and organic bonds, ammonia and aliphatic amines. Acids, acid halides and especially Lewis- The stabilization of the polymer against the influence

Acids (see Kortüm, textbook of electrochemistry, of heat, light and oxygen can, as with the Wiesbaden 1948, pp. 300 and 301). Other trioxane copolymers and terpolymers have been made from the latter.

As heat stabilizers, for. B. polyamides, amides of polybasic carboxylic acids, amidines and urea compounds suitable as oxidation stabilizers phenols, especially bisphenols and aromatic Amines. α-Oxybenzophenone derivatives are suitable for light stabilization.

The copolymers are particularly suitable for injection molding large-area objects, but also for extrusion as well as for the production of foils, films and fibers.

example 1

A trioxane solution containing 2 percent by weight of ethylene oxide and 0.5 percent by weight of diglycol diglycidyl ether is pumped into a co-kneader at 70 ° C. At the same time, a solution of BF ₃ dibutyl etherate in cyclohexane in a ratio of 1:80 is injected into the kneader, the pump speeds being regulated so that 80 ppm of BF _{3 dissolve} in the monomer mixture. The polymer is precipitated from the kneader into a l ° / ^e oig ammonia solution as quenching liquid. The product is ground wet and finally hydrolyzed heterogeneously in 1% ammonia solution in a ratio of 1: 4. The hydrolysis temperature is 141 ⁰ C, the pressure 3.6 atm. The product is washed and dried, the melt index according to ASTM-D1238-52 T is 4 = 9.8; i ₁₆ = 190 (Terpolymer I).

^15th

ao

Example 2

100 g of trioxane, 2 cm ³ of ethylene oxide, 0.6 cm ³ Triglykoldiglycidyläther be polymerized with 10 mg p-Nitrophenyldiazoniurnfluorborat as a catalyst in a thermostatic temperature of 7O ⁰ C in a screw-top jar. After the polymerization, the block is comminuted and ground and then homogeneously hydrolyzed for half an hour in ^{1 1 of} benzyl alcohol at 150 ° C. in the presence of 10 cm ^{3 of triethanolamine.} After the hydrolysis, it is precipitated with methanol and the suctioned-off product is boiled with methanol, washed and dried. The melt index is i ₂ = 1.1 and i ₂₀ = 82.9.

Unexpected technical advantages of the copolymers prepared according to the invention over known ones Copolymers result from the following comparative experiments.

Comparative example 1

The product prepared according to Example 1 was with a copolymer of 100 parts of trioxane and 2 parts of ethylene oxide obtained by the same method were compared. As a benchmark used spiral injection molding, which is a measure of the flowability of plastics. The length the spiral is measured in centimeters.

Stiffness Copolymer Terpolymer I Melt index Limit bending stress L. DIN 53452 kp / cm ² .. 9 9.8 U ₁ , Stiffness 90 190 Spiral injection molding Ball indentation hardness at 40 atm DIN 53456 kp / cm ² .. 22 cm 45 cm at 50 atm Torsion 26.5 cm 53 cm at 60 atm stiffness 12O ⁰ C 30 cm 59.5 cm Notched impact strength DIN 53447 kp / cm ² .. DIN 53453 M ⁰ " ¹ 5 5 cm ² 1010 1170 1355 1555 1500 1880

Comparative example 2

100 g of trioxane, 2 cm ^{3 of} ethylene oxide, 0.8 cm ^{3 of} butanediol diglycidyl ether are polymerized with 10 mg of p-nitrophenyldiazonium fluoroborate at a thermostat ^{temperature of 70 °} C. in a screw jar. A hydrolysis of the product in benzyl alcohol is not possible because it is insoluble. In addition, the polymer is infusible and the spiral test cannot be carried out. Because of the obvious non-processability, the product has no technical interest. In the case of meltable terpolymers based on butanediol diglycidyl ether with lower termonomer concentrations which have been adjusted to the injection molding viscosity with the aid of regulators, the notched impact strength values are about 15% below those of the corresponding types of copolymers.

Claims (1)

Claim: A process for preparing copolymers of trioxane by polymerizing trioxane with cyclic ethers and difunctional compounds in the presence of catalysts at temperatures of -50 to +100 ⁰ C, characterized in that mixtures of a) 97.9 to 88.0 weight percent trioxane , b) 2 to 10 percent by weight of a cyclic in which R ₁ to R _{4 are} each hydrogen atoms, ethers of the formula alkyl radicals or halogen-substituted alkyl residues with 1 to 5 carbon atoms and R ₅ £ a methylene or oxymethylene radical, a ² 5 each alkyl or haloalkyl-substituted "Methylene or oxymethylene radical, where η ~ Y is an integer from 0 to 3, or the remainder R ₃ C- (R ₅ ) * - (O -CH ₂ -CH ₂ V-OCH ₂ - ! ίο mean, where η is 1 and m is a whole R _{4 is a} number from 1 to 3, and c) O ₅ I to 3 percent by weight of a polyglycol diglycidyl ether of the formula CH ₃ CH-CH ₂ - (O-CH ₂ -CH ₂ ) ,, - O-CH ₂ -CH CH ₂ in which η is an integer from 2 to 5, polymerized.