Abstract: Disclosed is a test and test apparatus used to determine whether lactic acid is suitable for polymerization. The test apparatus comprises a) means for the polycondensation of the lactic acid to form a pre-polymer, b) means for depolymerization of the prepolymer to form dilactide, and c) means for carrying out analytical methods to determine at least one of the dilactide yield and/or the racemization, wherein lactic acid which is suitable for polymerization exhibits a dilactide yield of >90% and a racemization of <5%.

Abstract: The present disclosure relates to a thin film type controlled viewing window back light unit and a thin flat type Controlled Viewing window Display using the same. The present disclosure suggests a thin film type back light unit which can include: a base film having a width and a length, and including a high refractive film and a low refractive film stacked on the high refractive film; an incident pattern disposed at one side of a bottom surface of the base film; a reflective pattern disposed at an opposite side apart from the one side with the length of the bottom surface of the base film, and covering the width of the opposite side; a light radiating pattern disposed on an upper surface of the base film; a holographic film for controlling a viewing-window disposed on the light radiating pattern; and a light source being apart from the incident pattern, and providing an incident light to the incident pattern.

Abstract: The invention relates to a method for producing a security element having a holographic layer in which a hologram is arranged, characterized by at least the following steps: a) providing the holographic layer; b) exposing the holographic layer at least in sections via a master hologram to produce a hologram copy in the holographic layer; e) printing the holographic layer at least in sections with an ink, forming a printed feature, wherein the ink comprises the melt of a dye or a colorless component or a solvent and a dye dissolved therein or a colorless component dissolved therein; d) fixing the exposed holographic layer to produce the hologram in the holographic layer, wherein the printed feature and the hologram are arranged in the holographic layer such that the printed feature and the hologram overlap at least in sections. The invention further relates to a security feature which is produced or can be produced by said method.

Abstract: The present invention relates to a device and also to a method for separating and recovering a cyclic diester, in particular dilactide or glycolide from polymer melts which include the cyclic diester as impurity. The device and also the method according to the invention allow recovery of the cyclic diester with a high yield and at the same time high purity.

Abstract: The invention relates to a method for the production of a high-molecular polyester or copolyester which comprises at least three method steps. In a first method step, a paste is produced from at least one aromatic dicarboxylic acid or the diester thereof or the acid anhydride thereof and also from at least one aliphatic dicarboxylic acid or the diester thereof or acid anhydride thereof and also from at least one dialcohol and also the required quantity of transesterification- or polycondensation catalyst. This paste is converted into a prepolymer in a second step at increased temperature and, in the third method step, this obtained prepolymer is polycondensed or copolycondensed at reduced pressure relative to normal conditions. The implementation of the method can be effected continuously and also discontinuously. Furthermore, the invention relates to polyesters and copolyesters produced in this way and also to biodegradable polymer blends comprising these.

Abstract: The invention relates to a planar light distribution module for a display, comprising a light guide plate through which light coupled in via at least one side face can propagate by means of total reflection, and at least one out-coupling device (2), which is applied on one or both of the main faces of the light guide plate (1), is in optical contact therewith and has a multiplicity of holographic optical elements (13) formed therein, which are configured in such a way that they can couple light out of the light guide plate (1), the light distribution module being characterized in that the holographic optical elements (13), independently of one another, have an extent of at least 300 ?m in at least one spatial axis extending parallel to the surface of the out-coupling device (2). The invention furthermore relates to an optical display, in particular an electronic display.

Abstract: The invention relates to a planar light distribution module for a display, comprising a light guide plate through which light coupled in via at least one side face can propagate by means of total reflection, and at least one planar out-coupling device (2), which is applied on one or both of the main faces of the light guide plate (1), is in optical contact therewith and has a multiplicity of holographic optical elements (13) formed therein, which are configured in such a way that they can couple light out of the light guide plate (1), the light distribution module being characterized in that the holographic optical elements (13) are arranged in the out-coupling device (2) without translational symmetry. The invention furthermore relates to an optical display, in particular an electronic display, which contains a light distribution module according to the invention.

Abstract: The present disclosure relates to a method for producing a beam shaping holographic optical element, which is configured to generate diffracted beams configured to reconstruct an image of a diffusor irrespectively of the point of impact of a pencil of light on the beam shaping holographic optical element, comprising providing a recording element, providing a master element comprising a particular pattern, forming a recording stack comprising the recording element and the master element such that the master element is arranged to the recording element in a closed-copy distance, irradiating at least a part of the recording stack with a reconstruction beam, irradiating at least a part of the recording stack with a reference beam, wherein at least one of the reconstruction beam or reference beam penetrates the master element to record the pattern of the master element onto the recording element.

Abstract: The invention relates to an illumination device for illuminating at least one light modulator system of a liquid crystal display, the device comprising at least one waveguide substrate for guiding at least one targeted light beam that can be coupled into the waveguide substrate. The waveguide substrate is at least in optical contact with at least one holographic optical decoupling substrate comprising a plurality of decoupling regions and a decoupling region is at least designed to decouple part of the targeted light beam in the form of a plurality of sub-beams in the direction of the light modulator system. At least one diffuser module is provided, said diffuser module being designed in such a way that at least the outermost sub-beams of two neighbouring decoupling regions are at least adjacent to one another before exiting the diffuser module.

Abstract: A mixture of cyclic diesters derived from lactic acid and in cases a mixture of a racemate of dilactide may be produced in several different processes. In some instances, the process can thereby start from the corresponding alpha-hydroxycarboxylic acids, the corresponding cyclic diesters or oligomers of the corresponding alpha-hydroxycarboxylic acids.

Abstract: The present invention relates to a device for separating a biodegradable, intermolecular cyclic diester of an alpha-hydroxycarboxylic acid from material mixtures which contain in addition the alpha-hydroxycarboxylic acid of the diester corresponding thereto. In particular, the diester is thereby dilactide and the acid lactic acid. Furthermore, the present invention relates to a method for separating dilactide from material mixtures, which is based on a modified, distillative method. In addition, the present invention describes a polymerization device, in particular for preparing polylactide. Likewise, purposes of use of both the devices and of the method are indicated.

Abstract: Disclosed is a test and test apparatus used to determine whether lactic acid is suitable for polymerization.

Abstract: The present invention relates to a process for recovering lactide from polylactide (PLA) or glycolide from polyglycolide (PGA), in which, in a first step, PLA or PGA is contacted with a hydrolysing medium and hydrolytically degraded to oligomers. In a further step, a cyclising depolymerisation of the oligomers obtained in the first step is effected to give lactide or glycolide. In addition, the present invention relates to an apparatus based on the combination of a hydrolysis apparatus with a depolymerisation reactor, with which the above-described process can be performed. The core of the process according to the invention is a partial hydrolysis of the polymeric materials originally used in combination with a cyclising depolymerisation.

Abstract: The present invention relates to a condensation and washing device with which in particular the process vapors which occur during the production of polylactide can be processed and cleaned. Furthermore, the present invention relates to a polymerization device for the production of polylactide and also to a method for processing process vapors which occur during the production of polylactide; possibilities for use of both the condensation and washing devices and of the method are likewise mentioned.

Abstract: The present invention relates to a device for separating a biodegradable, intermolecular cyclic diester of an alpha-hydroxycarboxylic acid from material mixtures which contain in addition the alpha-hydroxycarboxylic acid of the diester corresponding thereto. In particular, the diester is thereby dilactide and the acid lactic acid. Furthermore, the present invention relates to a method for separating dilactide from material mixtures, which is based on a modified, distillative method. In addition, the present invention describes a polymerisation device, in particular for preparing polylactide. Likewise, purposes of use of both the devices and of the method are indicated.

Abstract: The present invention relates to a device for separating a biodegradable, intermolecular cyclic diester of an alpha-hydroxycarboxylic acid from material mixtures which contain in addition the alpha-hydroxycarboxylic acid of the diester corresponding thereto. In particular, the diester is thereby dilactide and the acid lactic acid. Furthermore, the present invention relates to a method for separating dilactide from material mixtures, which is based on a modified, distillative method. In addition, the present invention describes a polymerization device, in particular for preparing polylactide. Likewise, purposes of use of both the devices and of the method are indicated.

Abstract: The invention relates to an autostereoscopic 3D display (1), comprising an illumination unit (2) having two light sources (3, 4), a light guide (5), a holographic-optical element (6) as a diffractive optical light directing element, a transparent display panel (7), and a control unit (8) for alternately synchronizing the light sources (3, 4) with a right and a left parallactic image represented on the display panel (7), wherein the light sources (3, 4) are oriented so as to irradiate light into the light guide (5) from various directions and the holographic-optical element (6) and the display panel (7) are arranged such that light emitted by the light guide is diffracted by the holographic-optical element (6) in two different directions, depending in the preferred direction of the light, and directed through the display panel (7), wherein at least one surface of he light guide (5) has a refractive surface (10).

Abstract: The present invention relates to a condensation and washing device with which in particular the process vapours which occur during the production of polylactide can be processed and cleaned. Furthermore, the present invention relates to a polymerisation device for the production of polylactide and also to a method for processing process vapours which occur during the production of polylactide; possibilities for use of both the condensation and washing devices and of the method are likewise mentioned.

Abstract: The present invention relates to a condensation and washing device with which in particular the process vapors which occur during the production of polylactide can be processed and cleaned. Furthermore, the present invention relates to a polymerization device for the production of polylactide and also to a method for processing process vapors which occur during the production of polylactide; possibilities for use of both the condensation and washing devices and of the method are likewise mentioned.

Abstract: The present invention relates to a polymerization reactor for continuous polymerization, the reactor being constructed in two stages and comprising a prepolymerization stage which is configured as a stirred vessel or as a loop-type bubble column and also a main polymerization stage which is configured as a tubular reactor. Furthermore, the present invention relates to a method for the production of biodegradable polyester, in particular polylactide, the reactor according to the invention being used. Likewise, the invention relates to a polymerization device which comprises further components in addition to the polymerization reactor.