Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/07—Flat, e.g. panels
  • B29C48/08—Flat, e.g. panels flexible, e.g. films
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/001—Combinations of extrusion moulding with other shaping operations
  • B29C48/0011—Combinations of extrusion moulding with other shaping operations combined with compression moulding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/30—Extrusion nozzles or dies
  • B29C48/305—Extrusion nozzles or dies having a wide opening, e.g. for forming sheets
  • B29C48/31—Extrusion nozzles or dies having a wide opening, e.g. for forming sheets being adjustable, i.e. having adjustable exit sections
  • B29C48/313—Extrusion nozzles or dies having a wide opening, e.g. for forming sheets being adjustable, i.e. having adjustable exit sections by positioning the die lips
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D11/00—Producing optical elements, e.g. lenses or prisms
  • B29D11/00663—Production of light guides
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
  • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
  • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
  • G02B6/0065—Manufacturing aspects; Material aspects
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/001—Combinations of extrusion moulding with other shaping operations
  • B29C48/002—Combinations of extrusion moulding with other shaping operations combined with surface shaping
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
  • B29C48/911—Cooling
  • B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
  • B29C48/914—Cooling of flat articles, e.g. using specially adapted supporting means cooling drums
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2033/00—Use of polymers of unsaturated acids or derivatives thereof as moulding material
  • B29K2033/04—Polymers of esters
  • B29K2033/12—Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
  • B29K2995/0037—Other properties
  • B29K2995/0072—Roughness, e.g. anti-slip
  • B29K2995/0073—Roughness, e.g. anti-slip smooth
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/34—Electrical apparatus, e.g. sparking plugs or parts thereof
  • B29L2031/3475—Displays, monitors, TV-sets, computer screens
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
  • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
  • G02B6/0033—Means for improving the coupling-out of light from the light guide
  • G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
  • G02B6/0036—2-D arrangement of prisms, protrusions, indentations or roughened surfaces

Definitions

• the present invention relates to a method for
• the present invention relates to a
• Light guide serve in particular for planar
• LCD liquid crystal displays
• Light guide bodies are the subject of EP 800 036.
• EP 656 548 discloses light-conducting bodies which use polymer particles as scattering bodies.
• EP 1022129 discloses light-conducting bodies comprising a particle-free, light-conducting layer
• the equipped layer having a thickness in the range of 10 to 1500 ⁇ comprises barium sulfate particles. According to this principle, the light is transmitted through the PMMA layer
• Plate thickness of the previously described light guide leads to a very strong decrease in the luminance relative to the direction of extension of the incident light. As a result, a very inhomogeneous lighting is obtained, the
• Another object of the present invention was to provide a simple and inexpensive method for producing light bodies which can be easily adapted in size and shape to the requirements.
• Light guide body according to the invention have a thickness
• the method is characterized in that it is a
• the plant used according to the invention may also have the following optional components: a
• Melt pump a melt filtration, a static mixing element and / or a winder.
• system used in the method according to the invention is characterized in that the
• Flat film nozzle has a die lip with adjusting elements for adjusting the nozzle lip width, and the
• Adjusting elements have a distance of 5 to 20 mm, preferably from 11 to 15 mm to each other.
• the gap of the die lip can be finely adjusted over the entire width of the die lip by means of the adjusting elements.
• a so-called flex lip or Flexdüsenlippe The nozzle body used in the method according to the invention has an outer geometry which is adapted to the shape of the smoothing rollers (Fig.l). This can be a
• the flanks of the nozzle body can also be rounded so that they assume the shape of the smoothing rollers complementary. As shown by way of example in FIG. 2, this can also be asymmetrical only with respect to one of the first two
• the distance from the melt outlet edge to the smoothing gap is set of less than 100 mm, preferably less than 80 mm, and in particular embodiments of less than 60 mm. Surprisingly, it has been found that a particularly good film quality, in particular with regard to the surface quality, can be achieved by particularly small distances between the melt outlet edge and the smoothing gap.
• the distance from the melt outlet edge to the calendering nip is defined in the context of this invention as the distance (6 in Fig. 2) between the melt outlet edge and the point in the middle between the calender rolls, which is the smallest distance (7 in Fig. 2) to the two Has smoothing rollers.
• the present invention relates to a
• Calender is aligned by laser. This ensures that the parallel deviation of the nozzle to the smoothing rollers, measured at the two ends of a
• the nozzle outsides are in this case, the two flanks of the flat foil nozzle, each parallel to the two smoothing rolls.
• the method is characterized in that the difference between the thinnest and the thickest point of the light guide is at most 8 ⁇ , preferably at most 5 ⁇ and more preferably at most 4 ⁇ .
• the light guide bodies according to the invention are distinguished by the fact that the thickness deviation in the light guide body is at most 4%, preferably at most 3%.
• the thickness deviation is determined starting from the thinnest point of the light guide.
• Deviation of 3% thus means that the thickness of the thickest point of the light guide is allowed to be at most 3% greater than the thickness of the thinnest point.
• the light guide produced by a method according to the present invention a particularly high resistance to weathering, especially against UV irradiation. Furthermore, the light guide body over the entire
• Light-guiding bodies is also particularly simple and inexpensive to perform.
• a hot melt is extruded from the die of the extruder to a gap between two smoothing rolls.
• melt for example, depends on the composition of the mixture and therefore can vary widely.
• Preferred temperatures of the PMMA molding compound to for the nozzle inlet are in the range of 150 to 300 ° C, more preferably in the range of 180 to 270 ° C and most preferably in the range of 200 to 220 ° C.
• the temperature of the smoothing rollers is preferably less than or equal to 150 ° C, preferably between 60 ° C and 140 ° C.
• the temperature of the nozzle is selected to be higher than the temperature of the mixture before the nozzle inlet.
• the nozzle temperature is preferably set higher by 10 ° C., particularly preferably by 20 ° C. and very particularly preferably by 30 ° C., than the temperature of the mixture before the nozzle inlet. Accordingly, preferred temperatures of the die are in the range of 160 ° C to 330 ° C, more preferably 190 ° C to 300 ° C.
• the calender used in the invention consists of two or three smoothing rollers. Smoothing rollers are well known in the art, with polished rollers used to obtain a high gloss. In the process according to the invention, however, other rolls can also be used as a smoothing roll. Through the gap between the two first smoothing rollers, a film is formed, which is the simultaneous cooling to a film.
• FIG. 1 schematically depicts an embodiment with three smoothing rollers.
• chrome surfaces and in particular by the fact that these chrome surfaces have a roughness Ra (according to DIN 4768) less than 0.10 ⁇ , preferably less than 0.08 ⁇ .
• the pressure with which the molten mixture is pressed into the nozzle can be controlled by the speed of the screw. The pressure is in
• the speed with which the films can be obtained according to the invention is generally greater than 5 m / min, in particular greater than 10 m / min.
• a melt pump can additionally be installed before the
• a filter is optionally arranged before the melt enters the nozzle.
• the mesh size of the filter is generally based on the
• a static mixing element can be installed in front of the flat film nozzle.
• components such as pigments, stabilizers or additives can be mixed into the polymer melt or up to 5% by weight of a second polymer, for example in the form of a melt from a second extruder, can be mixed with the PMMA.
• the molding compositions used to produce the methacrylate-based light-guiding bodies produced according to the invention are molding compositions which consist of at least 80% by weight, preferably at least 90% by weight and more preferably at least 95% by weight of polymethyl methacrylate (hereinafter PMMA for short) and none
• These polymers are generally obtained by free radical polymerization of mixtures containing methyl methacrylate. In general, these mixtures contain at least 80% by weight, preferably at least 90% by weight and more preferably at least 95% by weight, based on the weight of the monomers, of methyl methacrylate.
• these mixtures may contain further (meth) acrylates which are copolymerizable with methyl methacrylate.
• the term (meth) acrylates include methacrylates and acrylates as well as mixtures of both.
• compositions to be polymerized may also be further
• the unsaturated monomers that are copolymerizable with methyl methacrylate and the aforementioned (meth) acrylates include, inter alia, 1-alkenes, acrylonitrile, vinyl acetate, styrene, substituted styrenes, vinyl ethers or divinylbenzene. All of the stated monomers are preferably used in a high purity.
• the weight-average molecular weight M w of the homo- and / or copolymers to be used according to the invention can vary within wide limits, the
• Molecular weight is usually tailored to the application purpose and the processing of the molding material. In general, however, it is in the range between 20,000 and 1,000,000 g / mol, preferably 50,000 to 500,000 g / mol, and more preferably 80,000 to 300,000 g / mol, without this being intended to restrict this.
• Weight average molecular weight becomes medium
• Differ monomer composition Such particularly preferred molding compositions are commercially available under the trade name PLEXIGLAS ® from Evonik Röhm GmbH.
• the molding compositions may contain conventional additives.
• additives include, but are not limited to, antistatic agents, antioxidants, light stabilizers and organic phosphorus compounds, weathering agents and plasticizers.
• antistatic agents antioxidants, light stabilizers and organic phosphorus compounds, weathering agents and plasticizers.
• amount of additives is the application purpose
• optical waveguide at most 5 wt .-% and particularly preferably at most 2 wt .-% additives, wherein optical waveguide, which comprise substantially no additives surprisingly show exceptional performance.
• the form is
• Light guide as a multilayer, preferably as
• One layer represents the already executed PMMA light guide with the
• the guide body is a coextrudate with at least one PMMA layer and at least one PVDF layer.
• Quantities of the composition refer exclusively to the PMMA layer.
• the light guide body In addition to the procedure carried out are also the
• Light guide produced by the method according to the invention, and lighting units produced therefrom part of this invention.
• a lighting unit according to the invention comprises at least one light source and at least one light guide body.
• the light-conducting body consists of at least 80% by weight, preferably at least 90% by weight and particularly preferably at least 95% by weight, of PMMA and contains no impact modifiers.
• the light guide body has a thickness between 100 ⁇ and 1 mm, preferably between 125 ⁇ and 500 ⁇ , more preferably in the range of 100 ⁇ to 300 ⁇ . on. The difference between the thinnest and the
• the optical attenuation measured by a method according to a further below measuring method on a 0.5 mm thick film at a wavelength of 730 nm is less than 10000 db / km, preferably less than 9000 db / km and most preferably less than 8000 db / km. These values can be extrapolated to other thicknesses.
• the thickness here refers to the mean value of the smallest dimension of the optical waveguide measured perpendicular to the light propagation direction.
• the thickness can be determined by means of a stirrup micrometer or similar
• the illumination units are preferably distinguished by the fact that the thickness deviation in the light guide body is at most 3% and the yellowness of the light guide body (calculation according to DIN 6167, measurement according to DIN 5033) measured at Ü [D65 / IO °] smaller than 1, preferably smaller than 0.75 , more preferably less than 0.5 and especially
• the light source is preferably one or more light-emitting diodes (LED). These are particularly preferably positioned on the edge of the light guide body.
• the light guide bodies of the present invention have at least one light introduction surface and at least one light exit surface, the light introduction surfaces preferably having one or more outer edges of the light guide surface
• the light can also be transmitted through a prism
• the light can be irradiated over all four edge surfaces. This may be necessary in particular for very large light-guiding bodies. In the case of smaller light-conducting bodies, one or two light sources are generally sufficient.
• the light introduction surface is capable of light in the
• the surface of preferred light guide bodies formed parallel to the light exit surface comprises a region with structures and an area without structures, beyond which
• Light guide bodies can therefore have very well defined
• Regions of the surface intentionally emit light, which was coupled via the light introduction surface.
• the surface which is formed perpendicular to the light propagation direction, in addition to a light exit surface also have a surface over which only a small proportion of the incident light
• a small proportion means that the luminance in this area of the surface is at most 20%, particularly preferably at most 10% of that on the surface
• Light exit surface maximum measured luminance is. Areas with a low luminance do not count to the light exit surface.
• the ratio of light exit surface to light introduction surface is generally at least 1,
• the light guide body may have a tabular shape
• the smallest extent here is the thickness of the board.
• the largest extent is defined as length, so that the third dimension represents the width. From this it follows that the light exit surface of this embodiment is defined by the surface which corresponds to the product of length by width.
• the edge surfaces of the panel each defined as the surface formed by the product of length times thickness or width times thickness, can generally serve as a light entrance surface. Preferably, the edge surfaces serving as the light entrance surface are polished.
• Such a light guide body preferably has a length in the range from 20 mm to 3000 mm, preferably from 30 to 2000 mm and particularly preferably from 50 to 100 mm.
• the width of this particular embodiment is in the
• the invention is characterized by:
• Has surface of the light guide structuring and a contrast between the structured surface of the light guide and the non-structured surface of the light guide is present.
• the structuring can after the production of the
• Structuring can be achieved in the production of the films by using rolls having a negative of structuring.
• Light emission surface includes impurities that are able to decouple light. For example, points or notches can be applied.
• the light exit surface can also be roughened.
• the structurings have a depth in the range of
• Light propagation direction trained surface also areas without structures include. Areas of the surface over which a slight, preferably no light extraction should take place, preferably have a roughness Ra less than 0.10 ⁇ , preferably less than 0.08 ⁇ on.
• the density of the structuring can be over the entire
• the density change can be chosen to be much lower, since the
• BLU Back Light Unit
• LGP Light Guide Panel
• the measurement is performed on a Varian Cary 5000, equipped with an integration ball DRA2500.
• the measurement is made on film strips with a thickness of 0.5 mm, a width of 15 mm and a length of up to 970 mm.
• Spectrophotometer initiated in the face of the film sample. At the opposite end of the strip, the optically attenuated light falls into the integration sphere and is measured by the detector. In order to obtain a usable measurement signal, the light coupling into the very small area of the foil front side (for example 15 mm * 0.5 mm foil thickness) must be laid to the most intense point of the measuring beam. This necessary change in the beam path prevents the acquisition of a conventional baseline.
• Intensities are measured, which consist of the transmission through the film and the coupling losses.
• Auskoppelkoppellag en be compensated for the same. Measurements are made by first measuring a long strip (970 mm), which is then shortened to 530 mm and re-measured. As a result, the optical attenuation, taking into account the length difference and the detected intensities, is calculated as follows
• the determination of the measured value is carried out by
• Fig.2 Clarification of the distances nozzle lip to calender

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Manufacturing & Machinery (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Health & Medical Sciences (AREA)
• Ophthalmology & Optometry (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Planar Illumination Modules (AREA)
• Light Guides In General And Applications Therefor (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Citations (5)

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• 2010
  • 2010-12-13 DE DE102010062900A patent/DE102010062900A1/de not_active Withdrawn
• 2011
  • 2011-11-11 JP JP2013543597A patent/JP5930326B2/ja not_active Expired - Fee Related
  • 2011-11-11 KR KR1020157027396A patent/KR20150119481A/ko not_active Application Discontinuation
  • 2011-11-11 EP EP11790897.0A patent/EP2651618A2/de not_active Withdrawn
  • 2011-11-11 MX MX2013006672A patent/MX336822B/es active IP Right Grant
  • 2011-11-11 BR BR112013014768A patent/BR112013014768A2/pt not_active Application Discontinuation
  • 2011-11-11 KR KR1020137018262A patent/KR101714115B1/ko active IP Right Grant
  • 2011-11-11 US US13/993,882 patent/US9442237B2/en active Active
  • 2011-11-11 WO PCT/EP2011/069893 patent/WO2012079865A2/de active Application Filing
  • 2011-11-11 CN CN201180065289.XA patent/CN103328182B/zh not_active Expired - Fee Related
  • 2011-12-08 TW TW100145335A patent/TWI623409B/zh not_active IP Right Cessation
• 2013
  • 2013-06-12 IL IL226887A patent/IL226887A/en active IP Right Grant
• 2014
  • 2014-01-14 HK HK14100390.0A patent/HK1187306A1/zh not_active IP Right Cessation

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