Abstract: The present invention relates to a process for the preparation of oxymethylene polymers, the oxymethylene polymers obtained therefrom as well as their use.

Abstract: Oxymethylene polymers having a bimodal distribution or having a distribution of higher modality and having a targeted content of a low molecular weight fraction of from 1 to 5 percent by mass are described. Moldings of these polymers are distinguished by high low-temperature notched impact strength associated with a high modulus of elasticity.

Abstract: An initiator for cationic polymerization comprises a salt of a protic acid as well as a protic add. The molar ratio of protic acid to salt is in the range from 1:0.01 to 1:2000. The initiator is used for example for cationic homo- or copolymerization of trioxane, and permits stable and flexible operation of the polymerization.

Abstract: The present invention relates to a process for the preparation of oxymethylene polymers, the oxymethylene polymers obtained therefrom as well as their use.

Abstract: An initiator for cationic polymerization comprises a salt of a protic acid as well as a protic add. The molar ratio of protic acid to salt is in the range from 1:0.01 to 1:2000. The initiator is used for example for cationic homo- or copolymerization of trioxane, and permits stable and flexible operation of the polymerization.

Abstract: Oxymethylene polymers having a bimodal distribution or having a distribution of higher modality and having a targeted content of a low molecular weight fraction of from 1 to 5 percent by mass are described. Moldings of these polymers are distinguished by high low-temperature notched impact strength associated with a high modulus of elasticity.

Abstract: An initiator for cationic polymerization comprises a salt of a protic acid as well as a protic acid. The molar ratio of protic acid to salt is in the range from 1:0.01 to 1:2000. The initiator is used for example for cationic homo- or copolymerization of trioxane, and permits stable and flexible operation of the polymerization.

Abstract: Oxymethylene polymers having a bimodal distribution or having a distribution of higher modality and having a targeted content of a low molecular weight fraction of from 1 to 5 percent by mass are described. Moldings of these polymers are distinguished by high low-temperature notched impact strength associated with a high modulus of elasticity.

Abstract: An initiator for cationic polymerization comprises a salt of a protic acid as well as a protic acid. The molar ratio of protic acid to salt is in the range from 1:0.01 to 1:2000. The initiator is used for example for cationic homo- or copolymerization of trioxane, and permits stable and flexible operation of the polymerization.

Abstract: An initiator for cationic polymerization comprises a salt of a protic acid as well as a protic acid. The molar ratio of protic acid to salt is in the range from 1:0.01 to 1:2000. The initiator is used for example for cationic homo- or copolymerization of trioxane, and permits stable and flexible operation of the polymerization.

Abstract: Oxymethylene polymers having a bimodal distribution or having a distribution of higher modality and having a targeted content of a low molecular weight fraction of from 1 to 5 percent by mass are described. Moldings of these polymers are distinguished by high low-temperature notched impact strength associated with a high modulus of elasticity.

Abstract: A process for the cationically initiated preparation of oxymethylene copolymers in which, after the polymerization and after comminution of the crude polymer in a grinding assembly a portion of the deactivation suspension comprising the ground crude polymer is removed downstream of the grinding assembly and fed back to the process upstream of the grinding assembly. The return procedure predominantly reduces the proportion of oversize while the proportion of undersize rises only insignificantly. The treated crude polymer also has a lower proportion of unstable chain ends.

Abstract: A negative-working radiation-sensitive mixture containinga) a compound which generates a strong acid under the action of actinic radiation,b) a compound having at least two groups crosslinkable by means of acid andc) a polymeric binder which is insoluble in water and soluble or at least swellable in aqueous alkaline solutions,wherein the compound (a) comprises a di-, tri- or tetra-hydroxybenzene which may be further substituted, or a polymer containing a di-, tri-, or tetra- hydroxy phenyl radical, is esterified with respectively 2, 3 or 4 sulfonic acids of the formula R--SO.sub.3 H, and is distinguished by high resolution and high sensitivity over a wide spectral range. It also shows high thermal stability and does not form any corrosive photolysis products on exposure. A radiation-sensitive recording material produced with this mixture is suitable for the production of photoresists, electronic components, printing plates or for chemical milling.

Abstract: The invention relates to a positive-working radiation-sensitive mixture containing a) a compound which forms acid when exposed to actinic radiation, b) a compound containing at least one C--O--C or C--O--Si bond which can be cleaved by said acid, and c) a water-insoluble polymeric binder which is soluble, or at least swellable, in aqueous alkaline solutions, wherein the compound a) comprises the structure of the formulae I, II or III: ##STR1## The radiation-sensitive mixture according to the invention is notable for a high resolution and a high sensitivity over a wide spectral range. It also has high thermal stability and does not form any corrosive photolysis products on exposure to light.The invention furthermore relates to a radiation-sensitive recording material produced therefrom which is suitable for producing photoresists, electronic components, printed circuit boards or for chemical milling.

Abstract: Sulfonic acid esters are used as (a) compounds for forming a strong acid on irradiation in radiation-sensitive, positive or negative working mixtures also comprising (b) either a compound with at least one acid-decomposable C--O--C or C--O--Si bond (for positive working mixtures) or a compound with at least acid-cross-linkable groups (for negative working mixtures) and c) a binder which is insoluble in water but soluble or at least swellable in aqueous alkaline solutions, wherein said sulfonic acid esters are formula?R.sup.1 --CR.sup.2 (CF.sub.3)--O--SO.sub.2 --!.sub.n R.sup.3(I)orR.sup.1 ?--CR.sup.2 (CF.sub.3)--O--SO.sub.2 --R.sup.3 !m (II)wherein R.sup.1, R.sup.2, R.sup.3, n and n are defined with the body of the disclosure. These mixtures are particularly suitable for exposure to deep UV radiation in the formation of recording materials suitable for the production of photoresists, electronic components, and printing plates.

Abstract: The invention relates to a radiation-sensitive mixture comprising a) a binder which is insoluble in water but soluble or at least swellable in aqueous alkaline solution, b) a compound which forms an acid under the action of actinic radiation and c) a compound which contains at least one C-O-C or C-O-Si bond which can be cleaved by an acid, wherein said mixture additionally contains 0.1 to 70 mol %, based on the maximum amount of acid which can theoretically be produced from the compound b), of at least one compound having at least one nitrogen atom in an amine or amide bond. The mixture is used in particular in the production of electronic components. The invention also relates to a recording material having a substrate and a radiation-sensitive coating.

Abstract: Sulfonic acid esters of 2,4-bistrichloromethyl-6-(mono- or dihydroxyphenyl)-1,3,5-triazine are disclosed. Also disclosed is a negative-working radiation-sensitive mixture containing such a compound in combination with a compound containing at least two acid-crosslinkable groups, and a water-insoluble polymeric binder which is soluble or at least swellable in aqueous alkaline solutions. The esters are esters of a sulfonic acid or sulfonic acids of the formula R--SO.sub.3 H or R'(--SO.sub.3 H).sub.2 with 2,4-bistrichloromethyl-6-(mono- or dihydroxyphenyl)-1,3,5-triazine of the formulae I and/or II ##STR1## where R is an optionally further substituted (C.sub.1 -C.sub.10)alkyl, (C.sub.5 -C.sub.10)cycloalkyl, (C.sub.6 -C.sub.10)aryl, (C.sub.6 -C.sub.10)aryl-(C.sub.1 -C.sub.10)alkyl or (C.sub.3 -C.sub.9)heteroaryl radical, R' is an optionally substituted (C.sub.1 -C.sub.10)alkylene, (C.sub.6 -C.sub.10)arylene or (C.sub.3 -C.sub.9)heteroarylene radical, and n may be 1 or 2.

Abstract: A negative-working radiation-sensitive mixture which comprisesa) a compound, which forms a strong acid on irradiation, of the general formula ##STR1## in which R.sup.1 is a radical R.sup.2 --SO.sub.2 -- or R.sup.3 --C(O)-- andR.sup.2 and R.sup.3 independently of one another are an optionally substituted alkyl, cycloalkyl, aryl or heteroaryl radical,b) a compound containing at least two reactive groups which can be crosslinked by an acid andc) a water-insoluble binder which is soluble or at least swellable in aqueous-alkaline solutions, is described.The radiation-sensitive mixture according to the invention is distinguished by a high sensitivity over a wide spectral range. It likewise exhibits a high heat stability and forms no corrosive photolysis products on exposure to light.

Abstract: A negative-working radiation-sensitive mixture containinga) a compound which contains at least one --CBr.sub.3 group bound to an atom not linked in turn to a hydrogen atom,b) an alkoxymethylated melamine andc) a water-insoluble polymeric binder which is soluble, or at least swellable, in aqueous alkaline solutions and contains phenolic OH groups,wherein(1) the mixture has an absorption of <0.4 .mu.m.sup.-1 at 248 nm,(2) the CBr.sub.3 group of the compound a) is bound to the sulfur atom of a sulfonyl group and the compound a) is contained in the mixture in an amount of 0.2 to 10% by weight, based on the total amount of the components b) and c),(3) the ratio by mass of the components b) and c) is between 50:50 and 5:95 and(4) the component c) is a homopolymer or copolymer of hydroxystyrene or a derivative thereof, the homopolymer or copolymer having a removal rate of 200 to 3,000 nm/min at 21.degree. C. in an aqueous alkaline developer containing 2.

Abstract: A process for the preparation of polyoxymethylene copolymers, wherein 1,3,5-trioxane is polymerized with generally known comonomers in the presence of a strong protonic acid initiator and in the presence of a formaldehyde dialkyl acetal, and wherein the initiator is dissolved in the formaldehyde dialkyl acetal before admixing to the trioxane and the comonomers.