Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D1/00—Processes for applying liquids or other fluent materials
  • B05D1/34—Applying different liquids or other fluent materials simultaneously
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
  • B05D3/04—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases
  • B05D3/0493—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases using vacuum

Definitions

• the invention relates to a method for producing a cured plastic composition based on a two-component or multi-component reactive system and to a reactive system adapted thereto.
• Two-component or multi-component reactive systems are also used to produce molded articles with composite materials, in particular with fiber composite materials.
• the invention has for its object to provide a method for coating and / or painting of vehicle parts, with the complex forms of the vehicle parts and hard to reach areas can be coated or painted in good quality. This object is achieved by a method having the features of claim 1.
• the invention is also quite generally based on the object of providing a process for producing cured plastics compositions based on a two-component or multi-component reactive system of the type described above, with which a cured plastic composition having improved properties is obtained.
• the pressure reduction can abruptly, ie. in the range of approx. 10 to approx.
• Adjustable pressure differences are in particularly preferred cases in the range of about 0.01 bar to about 0.9 bar.
• the temperature of the reactive system may be desirable to raise the temperature of the reactive system, particularly to remove residual solvent and / or to accelerate the curing reaction of the plastic mass.
• the inventive method is particularly suitable for the mass production of products in which composite materials are used.
• a first embodiment of the invention after providing a two-component or multi-component reactive system, it is subjected to an elevated temperature and changing ambient pressure in an autoclave, for example application of an overpressure, an ambient pressure and / or a vacuum determined by the reaction conditions.
• pressure shock waves can also be provided which can include both short-term pressure increases and short-term pressure reductions in rapid succession.
• the microcapsules contain radicals, such as those resulting from the UV irradiation of UV photoinitiators. Particularly suitable are long-lived and / or stabilized radicals.
• radicals by means of light, in particular UV radiation, which can be integrated as part of the conditioning process into the process according to the invention, or else can take place when providing the two- or multi-component reactive system, so that the conditions for the production the radical encapsulated component can be chosen in a simple manner so that a complete activation of the component is given and shading effects, as in the prior art, are avoided.
• light in particular UV radiation
• the effect of the release of the microencapsulated component can in a variant of the method according to the invention during or after the reduction of the ambient pressure by means of application of sound waves, in particular infrasound in a frequency range of about 0.2 Hz to about 10 Hz or Ultrasound in a frequency range of about 20 kHz to about 500 kHz, to be supported.
• sound waves in particular infrasound in a frequency range of about 0.2 Hz to about 10 Hz or Ultrasound in a frequency range of about 20 kHz to about 500 kHz, to be supported.
• the method described above is also suitable in particular for plastic materials which constitute a composite material, are used as a lacquer or generally as a coating material, or also in the case of plastic materials which constitute a three-dimensional plastic component.
• the reactive system is injected according to a preferred variant in an injection mold.
• the plastic mass is applied by spraying or spraying or in the form of prefabricated fabrics (so-called "prepregs") inserted into the mold.
• prepregs are resin-impregnated mats or plates in which the reactive system is in the form of a solidified melt.
• the method is suitable for plastic compositions which represent a coating on a surface of a substrate, wherein the substrate may in particular also be a motor vehicle body or a part / module of a motor vehicle body.
• Modules of a motor vehicle body may be the frame (“spaceframe”), frame parts and attachments such as roof, hoods, fenders, side panels, doors and various small parts.
• the reactive system is applied to the substrate in a dip-coating operation, while according to another preferred variant, an application is carried out by means of spraying or spraying.
• the system in providing the reactive system, first the system is mixed with substantially all components except the microencapsulated component and only then the microencapsulated component is added to the reactive system. This is recommended, for example, when an activated reactive component is used, in particular in the form of a long-lived radical.
• the reactive system used can be present on the one hand as a dispersion (soft, deformable mobile microcapsules in liquid) or as a suspension (solid, hard microcapsules in liquid) or of a combination of soft and hard microcapsules in a liquid.
• the reactive system is present in a mixture of pulverulent components and the microencapsulated component and is therefore processed as a pulverulent solid mixture.
• the activation of the microencapsulated component can be carried out before or even during the addition to the reactive system.
• the activation of the microencapsulated component can be realized as a sub-step of the conditioning.
• the invention also relates, as mentioned above, to two-component or multi-component reactive systems according to claim 11, in particular for use in one of the above-mentioned processes, in which the reactive coating system comprises two or more reactive components, at least one of the components being present in encapsulated form whose encapsulation is destructible by means of pressure reduction.
• the encapsulated component of the reactive systems according to the invention comprises in particular an initiator, a catalyst and / or a reaction accelerator for the curing reaction of the reactive system.
• the microcapsules contain radicals, such as those resulting from the UV irradiation of UV photoinitiators.
• Particularly preferred two- or multi-component reactive systems are designed as a lacquer formulation, as an adhesive formulation, as a casting compound or as a mat or fiber-containing panels.
• Another preferred form of the two-component or multi-component reactive system according to the invention is that of a composite material, the material in particular comprising oriented or non-oriented short, long or continuous fibers selected from the group of glass fibers, carbon fibers, ceramic fibers, natural fibers and / or polymer fibers.
• particularly preferred reactive systems comprise additives, in particular in the form of colorants and fillers (pigments, dyes, etc.), and auxiliaries (leveling agents, plasticizers, light stabilizers, etc.).
• the reactive systems according to the invention preferably use microcapsules of an inorganic compound which are based in particular on SiO 2 , an average wall thickness of the encapsulation of from approximately 4 to approximately 100 nanometers, in particular approximately 10 to approximately 75 nanometers, is selected. With such wall thicknesses, it is ensured that the reactive system can be applied as a coating with the customary technical aids, used as a casting compound in the production of three-dimensional objects or can also be used to form composite materials during processing.
• an upper limit of the wall thickness of preferably about
• the encapsulation is carried out based on an organic compound (polymer shell), wherein then average wall thicknesses in the range of about 10 to about 50 nanometers are preferred.
• the encapsulated component can be safely handled in the reactive system in the typical method for applying the reactive system as a coating on substrates, when used as a casting material and / or during processing into composite materials.
• the encapsulation may be made of especially organic materials based on waxes or gelatin.
• the microcapsules In order to ensure a uniform distribution of the microencapsulated component in the reactive system and thus in all parts by volume uniform reaction conditions, it is recommended that the microcapsules with a mean capsule diameter of about 20 nm to about 10,000 nm, in particular about 20 nm to ca 1,000 nm, to use.
• a blowing agent is enclosed in the microcapsule.
• blowing agents in particular solvents, having a vapor pressure of about 20 mbar or more at 20 ° C.
• the reactive systems of the invention may be designed according to a particular embodiment as a pasty mass.
• the reactive system according to the invention is designed as a curable melt.
• Two- or multi-component reactive systems for the processes of the following Examples 1 to 6 can be e.g. develop from the reactive systems described in EP 1 497 338 Bl, to which reference is made in its entirety. In particular, reference may be made to the embodiments of EP 1 497 338 Bl.
• they are added according to the present invention in microencapsulated form to the reactive systems. The photoinitiators are still activated in the microencapsulated state by irradiation and the reactive system is subsequently applied to the substrates to be coated or injected into corresponding molds. Thereafter, the activated photoinitiators are released from the microcapsules, as described in detail in Examples 1 to 6 below.
• a workpiece for example a motor vehicle body or a motor vehicle module, is provided with a lacquer layer, for example a clear lacquer.
• a lacquer layer for example a clear lacquer.
• the workpiece is placed in a chamber and optionally exposed for about 10 minutes to a slight negative pressure of about 0.8 to 0.9 bar (absolute), whereby the residual solvent escapes from the paint film and thus dries the paint film.
• the pressure in the chamber is abruptly lowered (by opening a valve to a parallel chamber under vacuum) to approximately 0.2 bar to 0.1 bar (absolute).
• the microcapsules contained in the reactive system of the paint film break down within a short time and the curing component is released and causes within a short time (10 seconds to 2 minutes) the curing of the paint film.
• a workpiece for. B. a motor vehicle body or a motor vehicle module, with a lacquer layer, e.g. a clearcoat, provided.
• the workpiece is placed in a paint dryer, where the workpiece is exposed to a temperature increased by 40 to 120 K relative to the ambient temperature for about 5 to 15 minutes, whereby the residual solvent escapes from the paint film and thus dries the paint film.
• the workpiece is placed in a chamber and lowered within a few minutes or seconds (by opening a valve to a parallel chamber under vacuum), the pressure in the chamber to less than 0.1 bar.
• the microcapsules contained in the reactive system of the paint film break and the curing component is released and causes within a short time (10 seconds to 2 minutes), the curing of the paint film.
• a workpiece for example a motor vehicle component or a motor vehicle module, with a paint layer, for.
• a clearcoat provided as a clearcoat.
• the reactive system of the clearcoat composition is treated during application of the clearcoat to the component or module by means of UV radiation and thus activates its microencapsulated component.
• the workpiece is placed in a paint dryer, where the workpiece is exposed to a temperature increased by 40 to 120 K from the ambient temperature for about 5 to 15 minutes and / or a slight negative pressure of about 0.8 to 0.9 bar (absolute ), whereby the residual solvent escapes from the paint film and thus dries the paint film.
• the workpiece is placed in a chamber and within 2 minutes or abruptly (eg by opening a valve to a parallel chamber under vacuum), the pressure in the chamber to about 0.1 bar (absolute), ie. by a pressure difference of about 0.7 bar to 0.8 bar compared to the previously set pressure level or by a pressure difference of 0.9 bar lowered to atmospheric pressure.
• the microcapsules contained in the reactive system of the paint film break and the activated curing component is released and causes within a short time (10 seconds to 2 minutes), the curing of the paint film.
• a two- or multi-component plastic material (reactive system) is injected into a mold with or without inserted fiber reinforcement. Subsequently (or even during the injection), the workpiece formed by the tool shape is heated in the workpiece shape by 20 to 80 K from the original temperature and simultaneously increased in proportion to the temperature increase of the ambient pressure to a maximum of 10 bar (absolute). After uniform heating, the workpiece in the mold is abruptly lowered back to atmospheric pressure conditions. The microcapsules contained in the plastic compound break and the curing component is released and causes within a short time (10 seconds to 2 minutes) the curing of the plastic or composite part.
• a two- or multi-component plastic material (reactive system) is injected into a mold with or without inserted fiber reinforcement. Subsequently (or already during the injection), the workpiece formed by the tool mold is exposed in the workpiece mold to an ambient pressure (negative pressure) which is reduced compared to standard conditions, in particular atmospheric pressure. After reaching the maximum negative pressure of about 0.1 bar or less, the microcapsules contained in the plastic mass break and the curing component is released and effected within a short time
• a two- or multi-component Injected plastic mass in a mold with or without inserted fiber reinforcement part, a two- or multi-component Injected plastic mass (reactive system).
• the plastic mass Before injection, the plastic mass is irradiated in the supply line for up to a maximum of 1 minute with UV radiation, resulting in activation of the component contained in the microcapsules.
• the workpiece formed by the tool mold is exposed in the workpiece mold to a negative pressure. After reaching the maximum negative pressure of about 0.1 bar or less, the microcapsules contained in the plastic mass break and the curing component is released and causes within a short time (10 seconds to 2 minutes), the curing of the plastic or composite part.

Landscapes

• Application Of Or Painting With Fluid Materials (AREA)
• Paints Or Removers (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (2)

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ID=46210255

Family Applications (1)

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Citations (2)

Family Cites Families (4)

• 2011
  • 2011-06-06 DE DE102011050871A patent/DE102011050871A1/de not_active Withdrawn
• 2012
  • 2012-06-05 EP EP12726101.4A patent/EP2718025B1/de active Active
  • 2012-06-05 CN CN201280028042.5A patent/CN103608126B/zh not_active Expired - Fee Related
  • 2012-06-05 WO PCT/EP2012/060625 patent/WO2012168258A2/de active Application Filing

Patent Citations (2)

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