Abstract: Polyamic acids and corresponding polyimides are prepared by reacting polyfunctional amines, aromatic polyfunctional anhydrides or esters thereof, and allyl-nadic anhydride end capping agents, the resulting products exhibiting excellent properties and being suitable for the preparation of prepregs, composites, adhesives, coatings, and the like.

Abstract: Polyamic acids and corresponding polyimides are prepared by reacting phenylindane diamines, aromatic polyfunctional anhydrides or esters thereof, and nadic anhydride or allylnadic anhydride end capping agents, the resulting products exhibiting excellent properties and being suitable for the preparation of prepregs, composites, adhesives, coatings, and the like.

Abstract: Addition of compounds of formula I ##STR1## in which R.sup.1 to R.sup.4 are each hydroxyl or C.sub.1-6 -alkoxy and R.sup.5 to R.sup.10 are each hydrogen or C.sub.1-6 -alkyl,to positive photoresist compositions based on a diazoquinone/novolak resin effectively suppresses stray radiation and halation effects in corresponding photoresist coatings, in particular if these coatings have been applied to highly reflective substrates.

Abstract: A process for producing as end-product a heat-hardenable mixture forming thermosetting resin, e.g., a reactive hot-melt adhesive, comprises preparing a first pre-mixture by introducing a meltable heat-hardenable solid resin and liquid resin, flexibilizer, adhesion-promoter and/or plasticizer into a mixing zone in which the components are melted together; preparing a second pre-mixture by mixing with each other a heat-activatable hardener and thixotropic agent, hardening accelerator and/or electrical conductivity-imparting additive; introducing the melt into an extruding zone; and introducing the pulverulent pre-mixture into the extruding zone downstream of the melt-intake for mixing with the first pre-mixture at a temperature below said hardening temperature and in such amount that the content of the second pre-mixture in the end-product ranges from 10 to 50, preferably from 20 to 30 weight-% air occlusions in the melt and the extruded end-product being avoided.

Abstract: A high-pressure control valve (2) used in chromatography serves as a counter pressure control valve which, in a separating column, is intended to maintain a specific predeterminable pressure. The valve has a valve seat (12) with an outlet channel opening (18) located in its center and a valve body (13) that cooperates with the valve seat. The valve body (13) can be moved with the aid of a piezo transducer, actively in the opening direction and, while being monitored, actively in the closing direction. The opposed faces of the valve seat (12) and the valve body (13) are so shaped that an annular gap (16) that widens radially towards the outside starting from the opening (18) of the outlet channel is produced. When the valve is in the closed position, this results in the formation of a narrow sealing zone directly at the edge of the opening of the outlet channel.

Abstract: Lubricants stabilized against oxidative degradation by the incorporation therein of N-thiomethylphenothiazine derivatives, as well as certain phenothiazines within the indicated group.

Abstract: Positive-working photoresist compositions containing 23-27%, based on said composition, of at least one compound of formula (I) ##STR1## wherein one of the substituents X is hydrogen or a group of formula II ##STR2## and the other substituents X are a group of formula II; and 6-11%, based on said composition, of at least one polyhydroxy compound of formula III ##STR3## wherein X is a direct bond, --O--, --S--, --SO.sub.2 --, --CO-- or C(R.sub.6 (R.sub.7)--, and R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently of the other hydrogen, halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy or hydroxy, and R.sub.6 and R.sub.7 are each independently of the other hydrogen, --CH.sub.3 or --CF.sub.3.These compositions have particularly good profile contrast and exhibit insignificant fluctuations in line width.

Abstract: In a method of checking the gelling process after pouring a reactive resin system into a production mould, the gelling behavior of a resin system is detected by means of calibration measurements and stored. Temperature patterns of the resin system are detected and, for each temperature pattern, the temperature at which the gelling point lies is determined. A scalar value and the gelling moment temperature are associated with each temperature pattern. On carrying out a checking measurement inside a production mould, the temperature patterns at various sites inside the production mould are detected using a large number of thermocouples. Scalar values are obtained from the temperature patterns and are compared with the scalar values established during the calibration measurement in order to establish gelling moment temperatures. The particular advantage of the method described is that the checking measurement of a production mould requires the use only of thermocouples and not of gelling point probes.

Abstract: A process for converting crude pigments into pigmentary form wherein the crude pigment is premilled, then contacted with a polar solvent at temperatures below 50.degree. C., with or without the presence of particle growth inhibitors, and finally isolated.

Abstract: The advanced polymaleimide reaction product and solutions thereof resulting from the reaction of polymaleimides with alkenylphenols or alkenyl phenol ethers in the presence of specified molar amounts of an amine catalyst at elevated temperatures, the desired degree of resin advancement being reflected in solution stability and melt viscosity values.

Abstract: o-Hydroxyohenyl-s-triazines containing suitable functional groups are incorporated in polymers by copolymerisation, copolycondensation, copolyaddition or by polymer-analogous reaction. The modified polymers so obtained have excellent stability to degradation induced by light, oxygen and heat. They can also be used as stabilisers.

Abstract: Photocurable and solvent-developable compositions based on photopolymerizable (meth)acrylates, a photoinitiator for (meth)acrylates, an organic polymeric binder which comprises free carboxyl groups and has an acid number of at least 60, a blocked polyisocyanate crosslinking agent which has a cleavage temperature of at least 100.degree. C., and an inert solvent in an amount such that the photocurable composition is pourable, are described.

Abstract: Surface modification of a variety of pigments, particularly quinacridone pigments, and the pigments resulting therefrom whereby the pigment is treated with a poly(vinyl lower alkyl ether) and, optionally, with a dispersion-improving derivative of the primary pigment resulting in compositions exhibiting enhanced performance in automotive and other finish systems. The surface treatment also improves flow properties of the pigment in the aqueous phase of processing leading to higher solids content for direct application in waterborne systems.

Abstract: A vibratory conveyor for forming flowable grain agglomerations from previously poorly flowable fine-grained powder and thereafter conveying said agglomerations to a metering chamber which comprises a mechanical vibration device to agglomerate the poorly flowable powder, transport means for conveying the agglomerated powder and metering means for collecting and measuring the conveyed powder; and a method directed thereto wherein the poorly flowable powder is subjected to a mechanical vibration step prior to transport and metering.

Abstract: Curable compositions comprising(a) an aromatic bismaleimide of formula ##STR1## wherein R.sub.1 and R.sub.2 are identical or different and each is C.sub.1 -C.sub.4 alkyl, and R.sub.3 and R.sub.4 are each independently of the other a hydrogen or halogen atom, or a mixture of an aromatic bismaleimide of formula I and N,N'-4,4'-methylenebis(phenylmaleimide),(b) an alkenyl phenol, an alkenyl phenol ether or a mixture thereof, with the proviso that the alkenyl moiety contains at least 3 carbon atoms,are readily processable, well suited for the fabrication or prepregs or fibre-reinforced composites, and give mouldings having excellent ultimate strength.

Abstract: N--OR.sub.1 substituted hindered amine light stabilizers impart outstanding stabilization properties to ambient cured coatings based on a variety of resins, the stabilized coatings exhibiting improved durability, weatherability, and the like.

Abstract: A process for stabilizing bismuth vanadate pigments against attack by hydrochloric acid by treating said pigments with a metal phosphate, which process comprises treating an aqueous suspension of a bismuth vanadate pigment with 2-20% by weight, based on said pigment, of an orthophosphate selected from the group consisting of calcium, magnesium, aluminium, zirconium and titanium orthophosphate, of a mixture of such orthophosphates with one another or of such orthophosphates with zinc orthophosphate, with stirring, in the temperature range from 20.degree. to 100.degree. C. and in the pH range from 2 to 8, which orthophosphate is precipitated in situ from the appropriate metal salt of a strong mineral acid and orthophosphoric acid or from an alkali metal salt thereof, and isolating the resultant product by conventional methods.The pigments so obtained have excellent resistance to hydrochloric acid.

Abstract: In a device for injecting the light energy of a laser beam into a multimode fibre-optic optical waveguide (2) a small part of the light emerging from the end face of the optical waveguide (2) is projected through a beam splitting cube (7) and a reproducing lens (21) onto a display screen (1), so that an image (24) of the end face of the optical waveguide (2) can be observed on the display screen (1). The arrangement is such that the system is correctly focused only when the distance between the optical waveguide (2) and a focusing point of the laser beam (12) reaches an intended value. The light spot of the laser beam on the end face of the optical waveguide (2) is clearly visible on the display screen (1) so than an optimum positioning and adjustment can be readily effected.

Abstract: A transport device (1) for boards (2) or board-shaped workpieces, especially those having a sensitive surface, preferably for circuit boards which are coated with plastics material, for example UV-hardenable plastics material, with lacquer or the like and then dried, is constructed as a circulating coating system. The device (1) has holders (3) for taking hold of the boards (2) at the edges (2a) thereof when they are being handled, and advancing means, advantageously in the form of chains, for transporting those holders (3). The holder (3) has two parallel bars (10) on each of which there are provided two rows (11, 12) of prongs (13) arranged in the form of a rake, the prongs (13) of the one row (11) of a bar (10) forming an acute angle with those of the second row (12) of that bar (10) and the two rows (11, 12) accordingly being arranged with respect to each other in a "V" shape when viewed in cross-section.

Abstract: A method for the manufacture of contact lenses, especially individually fitted contact lenses, and a contact lens production system therefor is described, wherein the topography of the surface of the eye is measured three-dimensionally, the geometry of the rear face of the lens is determined so as to fit the topography measured, the optical effect of a lachrymal lens which is formed between the rear face of the lens and the surface of the eye is determined, the geometry of the front face of the lens is determined taking into account the optical effect of the lachrymal lens and the sight correction to be achieved, and the data so obtained for the lens geometry of the front and rear faces of the lens are stored and transferred to a control arrangement for the manufacture of the lens in a machine tool.