Hoechst Celanese Corporation

Celanese Gmbh

George L Collins

John R Costanza

William M Pleban

Hongkyu Kim

Kurt F Wissbrun

Paul Zema

Thomas M Powanda

Robert H Imes

Milton J Hayes

Anthony B Conciatori

James E Kuder

O Richard Hughes

Norman W Thomas

Edwina Ying

Thyagaraja Sarada

Diane Terrone

Milton J Hayes, Jr

Yusuf A Rashada

A crosslinked elastomeric acetal polymer is synthesized from 1,3-dioxolane, 1,3-dioxepane, and a polyfunctional crosslinking compound having two or more functional groups that react under conditions of cationic polymerization, such as 1,4-divinyloxybutane or poly(butadiene oxide). The polymers are elastomeric and non-crystalline at temperatures well below room temperature. They can be blended with crystalline acetal polymers to produce blends that have improved impact properties.

Crosslinked elastomeric acetal polymers

Crosslinked elastomeric acetal polymers are made by the copolymerization of 1,3-dioxolane with a smaller amount of one or more bifunctional monomers. The two functional groups of the bifunctional monomer react under the same cationic polymerization conditions as the 1,3-dioxolane. The elastomeric acetal polymer does not crystallize even when the temperature is as low as -50.degree. C. The elastomeric acetal polymer is particularly useful for blending with crystalline acetal polymers to yield a composition with improved impact resistance.

Elastomeric crosslinked poly(1,3-dioxlane)

Non-crystalline elastomeric acetal polymers are disclosed which have ethylenic unsaturation in the polymer backbone. The polymers are synthesized by the ring-opening polymerization of 1,3-dioxolane, 1,3-dioxepane, and the cyclic formal of an ethylenically unsaturated diol having at least 4 adjacent carbon atoms in its main chain. The preferred cyclic formal is 4,7-dihydro-1,3-dioxepin. Because of the ethylenic unsaturation, the elastomeric acetal polymers can be vulcanized or cured with multifunctional vinyl monomers to produce elastomers with improved properties, such as better elasticity, decreased thermoplasticity and decreased solubility. The elastomeric acetals in any of their embodiments are particularly useful for blending with crystalline acetal polymers to improve the impact resistance of the crystalline acetal polymers.

Vulcanizable non-crystalline acetal elastomers

There are provided novel mixtures and composites comprising a normally crystalline acetal polymer and a reinforcing material comprising glass fibers or filaments sized with a normally non-crystalline elastomeric copolymer of about 15 to 45 mol %, preferably about 25 to 35 mol % of trioxane, about 55 to 85 mol %, preferably about 65 to 75 mol % of 1,3-dioxolane, said mol percents based on the total of trioxane and 1,3-dioxolane, and about 0.005 to 0.15 wt. %, preferably about 0.05 to 0.12 wt. % of 1,4-butanediol diglycidyl ether or butadiene diepoxide as a bifunctional monomer, based on the total weight of copolymer.

Glass reinforced acetal polymer products

There are provided new moldable blends of a normally crystalline acetal polymer and a normally non-crystalline elastomeric copolymer of about 15 to 45 mol %, preferably about 25 to 35 mol % of trioxane, about 55 to 85 %, preferably about 65 to 75 mol % of 1,3-dioxolane, said mol percents based on the total of trioxane and 1,3-dioxolane, and about 0.005 to 0.15 wt. %, preferably about 0.05 to 0.12 wt. % of 1,4-butanediol diglycidyl ether or butadiene diepoxide as a bifunctional monomer, based on the total weight of copolymer.

Acetal polymer blends

An injection moldable ceramic composition is prepared by mixing a sinterable powder, a polyacetal binding agent and silicon carbide whiskers which have been coated with a polyacetal resin.

Whisker-reinforced ceramic matrix composite by injection molding

Copolymers of 1,3-dioxolane and 1,3-dioxepane in the form of non-crystalline high molecular weight elastomers having low glass transition temperatures (Tg) are disclosed. Such copolymers are formed by polymerizing from about 40 to about 60 mol percent of 1,3-dioxolane and correspondingly from about 60 to about 40 mol percent of 1,3-dioxepane under substantially anhydrous conditions in the presence of a cationic polymerization catalyst, e.g., a strong Bronsted acid such as trifluoromethanesulfonic acid. Blends of such non-crystalline copolymers with crystalline oxymethylene polymers are also disclosed.

Non-crystalline acetal copolymer elastomers

A process for producing oxymethylene copolymers and terpolymers is disclosed which involves the non-linear addition of gaseous formaldehyde to a cyclic ether having at least two adjacent carbon atoms (1) and, in the case of a terpolymer, to a mixture of at least one (1) and one monoethylenically unsaturated aliphatic diol formal having at least four carbon atoms in its main chain (2), or to a mixture of (1) with a (2), in the presence of a polymerization initiator at a rate controlled so as to conform to a rate determined by kinetic equations that describe the rate of decomposition of trioxane to formaldehyde during conventional copolymerization of trioxane with a cyclic ether. The process and kinetic equations of the invention are applicable to batch reactions, single stream continuous reactions and dual stream continuous reactions.

Production of acetal copolymers from gaseous formaldehyde and cyclic

There are provided new articles comprising elements having surfaces bonded together with a bonding resin which is an elastomeric copolymer of about 15 to 45 mol %, preferably about 25 to 35 mol % trioxane, about 55 to 85 mol %, preferably about 65 to 75 mol % of 1,3-dioxolane, said mol percents based on the total of trioxane and 1,3-dioxolane, and about 0.005 to 0.15 wt. %, preferably about 0.05 to 0.12 wt. % of 1,4-butanediol diglycidyl ether or butadiene diepoxide as a bifunctional monomer, based on the total weight of copolymer. Preferably, at least one of said surfaces, and more preferably at least two of said surfaces bonded to each other are of a crystalline acetal polymer comprising at least 85 mol % of polymerized oxymethylene units.

Articles utilizing acetal copolymer bonding resins

There are provided new elastomeric copolymers of about 15 to 45 mol %, preferably about 25 to 35 mol % trioxane, about 55 to 85 mol %, preferably about 65 to 75 mol % of 1,3-dioxolane, said mol percents based on the total of trioxane and 1,3-dioxolane, and about 0.005 to 0.15 wt. %, preferably about 0.05 to 0.12 wt. % of 1,4-butanediol diglycidyl ether or butadiene diepoxide as a bifunctional monomer, based on the total weight of copolymer. The elastomeric copolymers may be prepared by mixing said monomers in a substantially dry state and under an inert atmosphere with a cationic polymerization catalyst, e.g., p-nitrobenzenediazonium tetrafluoroborate. The elastomeric copolymers have a strong interaction with moldable, crystalline acetal polymers comprising at least 85 mol % of polymerized oxymethylene units and may be used as a blending agent with such crystalline acetal polymers or as a bonding agent to improve the adhesiveness of the crystalline acetal polymer to other materials.

Process for producing elastomeric acetal polymers

There are provided new elastomeric copolymers of about 15 to 45 mol %, preferably about 25 to 35 mol % trioxane, about 55 to 85 mol %, preferably about 65 to 75 mol % of 1,3-dioxolane, said mol percents based on the total of trioxane and 1,3-dioxolane, and about 0.005 to 0.15 wt. %, preferably about 0.05 to 0.12 wt. % of 1,4-butanediol diglycidyl ether or butadiene diepoxide as a bifunctional monomer, based on the total weight of copolymer. The elastomeric copolymers may be prepared by mixing said monomers in a substantially dry state and under an inert atmosphere with a cationic polymerization catalyst, e.g, p-nitrobenzenediazonium tetrafluoroborate. The elastomeric copolymers have a strong interaction with moldable, crystalline acetal polymers comprising at least 85 mol % of polymerized oxymethylene units and may be used as a blending agent with such crystalline acetal polymers or as a bonding agent to improve the adhesiveness of the crystalline acetal polymer to other materials.

Elastomeric acetal polymers

The instant invention involves a process for preparing carboxylic acid esters which comprises coreacting a carboxylic acid and an aliphatic mono or polyol by maintaining one of the reactants in a reactor at elevated temperatures and adding the other reactant to the reactor over a period of time. By employing this process esterification times are significantly reduced.

Accelerated preparation of carboxylic acid esters

The instant invention involves a process for preparing acrylic acid esters which comprises coreacting an acrylic acid and an aliphatic mono or polyol by maintaining one of the reactants in a reactor at elevated temperatures and adding the other reactant to the reactor over a period of time. By employing this process esterification times are reduced significantly.

Accelerated preparation of esters

Oxymethylene polymer bonded articles, such as multilayer laminates, are disclosed. Such articles are prepared by bonding together at least two articles shaped or molded from crystalline oxymethylene homo-, co- and terpolymers using, as an adhesive, a low Tg copolymer of trioxane and 1,3-dioxolane which have a dioxolane content greater than 65 mol percent and less than about 75 mol percent and an IV of from about 1.0 to about 2.3, and which are non-crystalline at room temperature or above.

Acetal polymer bonded articles and method of making same

Low Tg copolymers of trioxane and 1,3-dioxolane which have a dioxolane content greater than 65 mol percent and less than about 75 mol percent and an IV of from about 1.0 to about 2.3, and which are non-crystalline at room temperature or above, are disclosed. These polymers, when blended with crystalline oxymethylene polymers, improve the latter's impact properties. They can also be used as adhesives for crystalline oxymethylene polymers.

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Maplewood, NJ, United States of America

George L Collins