摘要:
A photopolymerizable recording composition which comprises a mixture, containing a photoinitiator, of (a) a photopolymerizable olefinically unsaturated monomer and (b) an organic polymeric binder, wherein the photoinitiator is an acylphosphine oxide compound of the formula R.sup.1 R.sup.2 PO-CO-R.sup.3, where R.sup.1 and R.sup.2 are certain organic radicals and R.sup.3 is tert.-alkyl or a cyclic radical with two substituents in the ortho-position to the carbonyl group. The recording compositions have a high reactivity when irradiated with UV light and are used in particular for the preparation of printing plates, relief plates and photoresists.
摘要:
A photopolymerizable recording composition which comprises a mixture, containing a photoinitiator, of (a) a photopolymerizable olefinically unsaturated monomer and (b) an organic polymeric binder, wherein the photoinitiator is an acylphosphine oxide compound of the formula R.sup.1 R.sup.2 PO--CO--R.sup.3, where R.sup.1 and R.sup.2 are certain organic radicals and R.sup.3 is tert.-alkyl or a cyclic radical with two substituents in the ortho-position to the carbonyl group. The recording compositions have a high reactivity when irradiated with UV light and are used in particular for the preparation of printing plates, relief plates and photo-resists.
摘要:
Relief plates and printing plates are produced by a positive-working process, using a photopolymerizable layer which contains one or more photopolymerizable, olefinically unsaturated compounds, one or more photoinitiators which can be activated by UV light, and a combination of a phenothiazinium, phenoxazinium, phenazinium or acridinium dye with a mild reducing agent which, on exposure to visible light, is capable of reducing the dye in the excited electronic state. The photopolymerizable layer is exposed imagewise to light having a wavelength longer than 450 nm, and simultaneously or subsequently exposed uniformly to light having a wavelength of from 300 to 420 nm, after which the unpolymerized areas of the layer are removed.
摘要:
Photosensitive recording materials which are suitable for the production of printing plates and relief plates and possess a photopolymerizable relief-forming layer which can be developed with water and is based on a polyvinylalcohol/monomer mixture contain, as a binder in the said layer, a polyvinylalcohol derivative which is obtained by reacting polyvinylalcohol with an acylating agent which has groups which are polymerizable by free radicals, the reaction being carried out in the heterogeneous phase, in an aprotic dispersant, using the acylating agent in an amount which corresponds to not less than twice the molar amount required to achieve the desired degree of acylation.
摘要:
Multi-layer photopolymer elements, which are suitable for the production of relief printing plates and contain photosensitive polyvinyl alcohol/monomer layers which can be developed with water, can be improved in respect of their production, drying and shelf life by the application of a thin layer of a highly hydrolyzed low molecular weight polyvinyl alcohol.
摘要:
A laminate suitable for the production of printing plates and relief plates, and possessing a photosensitive layer, which is soluble in water or in an aqueous solution, and contains a hydrophilic polymeric binder, applied to a base, contains, between the base and the photosensitive layer, an intermediate layer which consists of a mixture of a polymeric binder which is compatible with the polymeric binder of the photosensitive layer and contains at least 30% by weight of a reaction product of a polyvinyl alcohol with acrylic anhydride and/or methacrylic anhydride, with at least one monomer which is compatible therewith and selected from the group consisting of the hydroxyalkyl acrylates and methacrylates and the diacrylates and dimethacrylates containing urethane groups. After application to the base, the intermediate layer is cured at 110.degree.-220.degree. C. before the photosensitive layer is applied.
摘要:
A method, system, and computer-readable media are provided for adjusting one or more video parameters of a video communication session based on a type of use for the video communication session. At least one method includes detecting a use for a certain video communication session and applying a profile of video parameters to the session based on the use. The method further includes detecting a network constraint and adjusting one or more of the video parameters based on the network constraint.
摘要:
Acoustic weight or mass sensing technology (referred to here as Acoustic Weigh In Motion (AWIN)) provides accurate weighing of any type of moving load moving over a load bearing medium. Acoustic transducers are affixed to or embedded in the load bearing medium. One or more source acoustic transducers propagate an acoustic wave over an acoustic path through the medium between the source and receiver transducers when the medium is in an unloaded state. The wave is detected at one or more receiving acoustic transducers. A propagation time delay is determined for the unloaded state. When a moving load travels over the acoustic path in the medium, the acoustic propagation time delay for that loaded state is determined. The difference between the acoustic propagation time delays for the unloaded and loaded states is determined. That acoustic propagation time delay difference is used to determine the weight or mass of the moving load.
摘要:
A method of measuring bone strength under dynamic loading is provided using an ultrasonic probe wave sensor to sense a low-frequency pump wave and an ultrasonic probe wave implemented to the bone. The bone is cyclically loaded with compressional and rarefactional pump waves, and probed with the probe wave that is timed according to the pump wave to determine the wave velocity of the probe wave. Bone strength is interpreted by measuring wave velocity changes during the pump wave cycles. Ultrasonic velocity derivatives are used to determine bone third-order (nonlinear) elastic constants that are linked to bone strength. High-resolution second-order (linear) elastic constants are provided through measurement of absolute phase velocity. A pulsed phase lock loop is locked at intervals as the probe wave phase is modulated over 360 degrees providing probe wave harmonic numbers that are correlated with the pump wave frequency to determine the probe wave velocity.
摘要:
Catalyst systems of the Ziegler-Natta type comprise as active constituents a) a solid component comprising a compound of titanium or vanadium, a compound of magnesium, a particulate inorganic oxide as support and an internal electron donor compound, and as cocatalyst b) an aluminum compound and c) if desired, a further, external electron donor compound, wherein the particulate, inorganic oxide used has a specific surface area of from 350 to 1000 m2/g and a mean particle diameter {overscore (D)} in the range from 5 to 60 &mgr;m and comprises particles which are composed of primary particles having a mean particle diameter {overscore (d)} in the range from 1 to 10 &mgr;m and contain voids or channels between the primary particles, where the macroscopic proportion of voids or channels having a diameter of greater than 1 &mgr;m in the particles of the inorganic oxides is in the range from 5 to 30% by volume and the molar ratio of the compound of magnesium to the particulate, inorganic oxide is from 0.5:1 to 2.0:1.