DE2019270A1 - Method and device for hardening a layer applied to a body - Google Patents

Description

DIPL..ING. H. FINK PATENTANWALT ■ 7300 ESSLINGEN (NECKAR) · HINDENBURGSTRASSE

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P 5812

j. April 21, 1970 ϋϊ

Robert Hildebrand Maschinenbau GmbH, 7446 Oberboihingen, Nürtinger Strasse 68

"Method and device for hardening a layer applied to a body"

The invention relates to a method for hardening a layer applied to a body from a layer after stimulation SertraMtn en§Fg £ § @ £ 3 @ ug§nä @ ß (isothermally governing)> organic material, especially oxidative drying paint, including Synthetic resin and oil varnishes are to be understood as meaning j and a device for carrying out the method.

A layer of the aforementioned material is generally exposed to air, possibly with the help of convection heat dried, that is, hardened. It is known that by ultraviolet irradiation (200 - 400 mMy wavelength) solidification many paint coats are accelerated very strongly katui, since the oxidation and polymerization processes during solidification * - tion of paints and varnishes based on linseed oil

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P 5812

April 21, 1970 Ul

UV irradiation accelerates the process by around ten thousand times will. It is also known that many synthetic resin paints solidify more quickly under UV radiation. This irradiation required for the hardening of exothermic reacting, post-reacting organic substances, especially oxidative drying Lacquers have a very high amount of energy, which makes the process uneconomical because of the high costs.

It is also known to paint on the basis of alkyd-phenol and Urea resins, asphalt paints and the like by infrared rays to dry.

The invention is based on the object of the hardening of exothermic organic substances Significantly reduce the amount of energy. This object is achieved according to the invention in that the substance is exposed to UV rays is irradiated, the wavelength of which lies in the resonance range of its radical and which is in the form of essentially the same Pulses having temporal intervals are generated. the Invention makes use of the knowledge that the energy-sucking (exothermic) reaction of the substance by a specific impulse can be excited, and runs on for at least a limited time. During the reaction is one UV irradiation not necessary, but also not disruptive. The greater the time, the lower the energy supply Distance between the pulses in relation to the pulse time. Since an impulse does not interfere with the energy-generating reaction of the paint it is advantageous for quick drying if the limited reaction time has not expired before the next pulse follows. The wavelength of the ultraviolet rays corresponds to the natural frequency of the radicals involved in the hardening or reaction oxidative curing paints are involved.

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P 5812

April 21, 1970 Ul

In a further development of the invention, the time interval is Impulse to the duration of the impulse is much greater than 1, in particular greater than 100. The higher this ratio is, the lower the power required for hardening. the The form of the impulse can be of any type.

A device for hardening a layer applied to a body from an exothermic after excitation by irradiation reacting, organic substance using an ultra- 'violet radiator is characterized in that this Emitter generates a wavelength that is in the resonance range of the Radical lies, and that the radiator is connected to an ignition device.

Further advantageous features emerge from the remaining claims, the description and the drawing. In this show

Pig «1 shows a cross section through a device as an embodiment of the subject matter of the invention in a schematic part division,

Fig. 2 is a graphical representation of from one to

ultraviolet emitters connected to an AC power source outgoing impulses,

Fig. 3 is a graphical representation of the impulses Io occurring in the embodiment example of a schematic Dars division,

Fig. 4 in the circuit diagram of the ignition device. ■

A conveying device 2 is accommodated in a housing 1 connected to the outside , which can be connected from the outside, for example.

: 109847/1530

⁰ INSPECTED

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P 5β12

2ΐ. April 1970

has driven conveyor rollers which are used to convey coated bodies. These bodies are provided with a layer 4 made of a synthetic resin or oil varnish, in particular an oxidatively drying varnish. In the exemplary embodiment, flat bodies 3 are shown. A tube 5 is attached to the ceiling of the housing which generates ultraviolet rays which have at least / ' a portion of rays of a certain wavelength or a certain frequency. The tube 5 is connected to an ignition device 6.

When the tube 5 is connected to a standard AC power source if it were, the pulses shown in FIG. 2 would be produced by it go out. However, the ignition device 6 generates in cooperation with the tube 5 pulses according to Fig. 3, which also have a different shape can have. Depending on the type of tube to be used, a A basic voltage that cannot be undershot may be necessary. One Basic voltage is z. B. not necessary for a xenon pulse tube with additional ignition winding, the tube housing of which has the desired wavelength in an advantageous manner permeable quartz or the like. When using a However, a mercury vapor lamp must have a basic voltage so that the tube does not go out.

The ignition device 6 for the tube 5 has according to FIG. 4 a transformer 7 connectable to an alternating current source

, the secondary side of which has a half-wave rectifier 8 and a Resistor 9 connected to the tube 5 with its electrodes is. A capacitor 10 is connected in parallel to the tube 5. A The ignition circuit also connected on the secondary side to the transformer 7 has a full-wave rectifier 11, 12 in bridge n-. circuit old a smooth capacitor 13, which is connected to the tube connected let. Hit the; Rectifier 11, 12 is across a resistor 14 a Zündicoo «# 08jator 15 terbuadeav to the eia

P 5812

21ν April 1970 ul

voltage or ignition transformer 16 and a switch 17 are parallel. The switch 17 can be a pulse switch, a thyristor or the like. The ignition transformer is connected to an ignition winding 18 of the tube 15. The ignition device 6 aims for short pulse times (approximately -Tq ₀₀ seconds) and long pauses. From Fig. 3 it can be clearly seen that the longer the pauses between the individual, possibly different impulses, the lower the power required for hardening.

The inventive device is used for hardening one on one Body applied layer of an exothermic reacting and post-reacting organic after stimulation by irradiation Fabric, especially an oxidative drying varnish. It is this z. B. a synthetic resin or oil varnish. That kind of varnish is relatively inexpensive and has a larger overall market share than the other paints.

The paints to be dried can be mixed with low-boiling solvents with a high evaporation number, e.g. B. ethyl acetate, Butanol, acetone or the like. Be added to the curing times to belittle. Photo initiators or light-sensitive substances serve as additives for the same purpose, e.g. B. ammonium dichromate, Chromic acid and the like. Chromic acid produced from ammonium dichromate at the moment of irradiation has a hardening effect.

The lacquers used or a mixture component thereof of more than $ 30> have an energy-generating or exothermic reaction when hardening, which are stimulated by pulses of a certain wavelength as soon as a certain energy threshold is exceeded and react within certain limits. The radical of the organic substance is excited in its natural frequency, which is involved in the hardening of oxidative drying

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P 5812

April 21, 1970 Ul

the paint is involved, which activates oxygen. the Radiation must have a frequency which corresponds to the resonance oscillation of the molecules that combine with oxygen. In the case of a certain type of paint, this corresponds to one wavelength of 197 »4 mMy or nm. An acceleration of the hardening is also achieved if a small proportion of the radiation has a wavelength that corresponds to one of the resonance lines of the Sauer Substance corresponds, z. B. 184.9 nm. It has also been found that if part of the radiation has a wavelength of 389.0 nm, this also contributes to the acceleration of hardening.

The number of pulses generated in the unit of time can depend on Type of paint may be different. It can vary depending on the type of Shift with two or ten to twenty impulses per second. With about six hundred pulses per unit area, a satisfactory hardening level was achieved, the number of times required for hardening The impulse naturally also depends on the layer thickness.

The energy required for curing is the lower, the more . greater is the time interval between the pulses and the duration of a pulse is. With a ratio of 100, good results were achieved with extremely low power consumption.

In the case of the substances used, the energy-generating or exothermic reaction run on for at least a certain time and pulses of a certain frequency can be stimulated.

¹ - 7 m,

109847/1530

Claims (1)

2 5912 ■ zn- Ap * ii 1970 A χι β Tt r ü c he , Method of hardening one applied to a body. Layer of an exothermic after excitation by irradiation reactive 'organic' substance, especially oxidative drying paint, thereby. g e k e η η indicates that the fabric is irradiated by ultraviolet rays' whose Wavelength lies in the resonance range of its radical and. in the form of essentially equal time intervals. having pulses are generated. 2. The method of claim 1, characterized geke η η ζ e ic h η et that the average time interval between two pulses to the average time duration of the pulse is much larger than 1, in particular greater than 100. % A method according to claim 1 or 2, characterized geke η η - ze ic h .'- et η that the wavelength is nm 19,714th 4 · Vtrfahrtn ntoh claims 3ι dafluroh gt k β η η β ei ο h net that an additional wavelength of 184.9 nm and / or 389.0 nm is used. 5. Apparatus for performing the method according to any one of the preceding claims using an ultraviolet emitter, daduroh geke η η ζ ei ch η et that this emitter generates a wavelength which is in the resonance range of the radical of the substance to be irradiated, and that the emitter is on an ignition device is connected. - '■ .. ■■ -. · ■■ - ^:. '. ■■ - ■ 6 «Device according to claim 5 ₁ characterized in that 41 · ignition device (6) is a DC power source (8) 109847 / ORIGINAL INSPECTED ? 5812 April 21 ifrr © Μ. with a capacitor lying parallel to the radiator (5) and a 25Ündkr <bis (11 fcie 17) * 7. The device of claim 5 Naeh barren 6, characterized jg e fc eh η ζ eieh ή e% News from Austria -WM Hsiöeüjpn -üNsr a xenon IIFL | jUlB ft8hre * Mi ^ auitlSlicher soft tube one ittr the aur- e * ö $ h (örnieü excitation ertördei * - Wavelength permeable h ^ 6. liaek for the implementation of the procedure according to one of the , before 1 to 4 and for use in the Vorriöhtung after einffii of claims 6 and 7 »thereby g e fc e η η ζ e 1 ö h η e t that he is a low-boiling solvent high ver steaming number 9. Lacquer according to claim 8, characterized in that g e k e η η ζ e i c h η e t, that he was an ichthyophantic Ötoff. contains. 10. Paint according to one of claims 8 and 9 »thereby g e k e η η shows that it has a minimum share of 30% min * at least one exothermic reacting and post-reacting, contains organic matter. 100847/1510 Lee on the side